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A Specialist Periodical ReportInorgani c Chemistry of the Mai n-Group Elements Volume 5 A Review of the Literature Published between October 1975 and Septern ber 1976 Senior Reporter C. C. Addison Reporters M. G. Barker G. Davidson M. F. A. Dove P. G. Harrison P. Hubberstey N. Logan D. B. Sowerby All of: Department of Chemistry, University of Nottingham The Chemical Society Burlington House, London WI V OBN British Library Cataloguing in Publication Data Inorganic chemistry of the Main-group elements. (Chemical Society; Specialist periodical reports). VOl . 5 1. Chemistry, Inorganic 2. Chemical elements I. Addison, Cyril Clifford 11. Series 546 QD151.2 72-95098 ISBN 0-85 186-792-8 ISSN 0305-697X Copyright @ 1978 The Chemical Society All Rights Reserved No part of this book may be reproduced or transmitted in any form or by any means-graphic, electronic, including photocopying, recording, taping or information storage and retrieval systems - without written permission from The Chemical Society Filmset in Northern Ireland at The Universities Press (Belfast) Ltd, and printed at The Pitman Press (Bath) Ltd. Preface I t has again been possible, in Volume 5 , to find authors for all chapters from amongst the inorganic chemists in the University of Nottingham, and the Senior Reporter would like to express his appreciation of the hard work to which they were prepared to commit themselves, and of the enthusiasm which they have shown. Because of financial pressures, we were called upon to produce a volume only two-thirds the length of Volume 4. The shorter the volume the more difficult becomes the task of choosing amongst the large number of worth-while research papers published during the year. Readers will detect a further move in the direction of structure and reactivity as against purely physical properties; for example, Chaper 4 no longer includes cover of binary and ternary intermetallic phases, which have been included in earlier volumes. All authors regret that much good work which merited mention has had to be omitted purely because of space limitation. Selection has to be based on originality and novelty, but also on the need to present a readable account, and thus to include reference to all published papers on any chosen theme. In this difficult task the authors have found that the opportunity to work as a team, and to maintain day to day discussion on possible overlap between chapters, has been of considerable advantage. C. C. ADDISON .I. 1ll con tents Chapter 1 Elements of Group I By P. Hubberstey 1 Introduction 2 The Alkali Metals as Solvent Media 3 Metallic Solutions and Intermetallic Compounds 4 Solvation of Alkali-metal Cations 5 Simple Compounds of the Alkali Metals Hydrides Oxides, Hydroxides, Sulphides, etc. Halides Molten Salts Halides Nitrates 6 Compounds of the Alkali Metals containing Organic Molecules or Complex Ions Radical-anion Salts Crown and Cryptate Complexes Lithium Derivatives Sodium Derivatives Potassium Derivatives Rubidium and Caesium Derivatives Chapter 2 Elements of Group I I By P. Hubberstey 1 Introduction 2 Alloys and Intermetallic Compounds Transition Metals and Rare Earths Main-Group Elements 3 Binary Compounds Oxides, Sulphides, and Related Species Halides 4 Ternary Compounds H ydrides Oxides Halides V 1 1 1 6 7 11 11 12 14 15 15 18 19 19 21 27 29 31 33 35 35 36 36 36 38 38 40 40 40 40 41 vi 5 Compounds containing Organic or Complex Ions Beryllium Derivatives Magnesium Derivatives Calcium Derivatives Strontium and Barium Derivatives Chapter 3 Elements of Group 111 By G. Davidson 1 Boron Boranes Borane Anions and Metallo-derivatives Carba- and other Non-metal Hetero-boranes Metallo- hetero boranes Compounds containing B-C Bonds Aminoboranes and other Compounds containing Compounds containing B-P or B-As Bonds Compounds containing B-0 Bonds Compounds containing B-S or B-Se Bonds Boron Halides Boron-containing Heterocycles Boron Nitride, Metal Borides, etc. B-N Bonds 2 Aluminium General Aluminium Hydrides Compounds containing Al-C Bonds Compounds containing Al-N Bonds Compounds containing A1-0 or Al-Se Bonds Aluminium Halides 3 Gallium Compounds containing Ga-N, Ga-P, or Ga-As Bonds Contents 43 43 45 49 52 54 54 54 55 59 65 72 73 76 77 80 81 83 88 89 89 89 90 91 92 96 99 99 Compounds containing Bonds between Gallium and 100 Gallium Halides 102 Atoms of Elements of Group VI 4 Indium 103 General 103 Compounds containing Bonds between Indium and 103 Indium Halides 104 Atoms of Elements of Group VI 5 Thallium Thallium(II1) Compounds Thallium(1) Compounds Other Thallium Compounds 106 106 107 108 Contents vii Chapter 4 El ement s of Group IV 109 By P. G. Harrison 1 Carbon Carbon Allotropes Chemical Reactions Intercalation Compounds Carbon Compounds Hydrocarbons Halogen Derivatives Oxygen and Sulphur Derivatives 0 ther Derivatives 109 109 111 113 114 114 114 116 118 2 Silicon, Germanium, Tin, and Lead 118 118 119 Simple Oxides 119 122 Molecular Silicon(1v)-, Germanium(w)-, Tin(rv)-, and 125 Halogen Derivatives 134 Sulphur, Selenium, and Tellurium Derivatives 141 Sulphides, Selenides, and Tellurides 141 Molecular Sulphur and Selenium Compounds 142 Nitrogen and Phosphorus Derivatives 144 Derivatives with Bonds to Main-Group Metals 145 Derivatives with Bonds to Transition Metals 150 Bivalent Derivatives 157 Subvalent Chemistry 172 Hydrides of Silicon, Germanium, and Tin The Metal(w) Oxides and Related Oxide Phases Silicates, Germanates, and Related Materials Lead (Iv)-Ox y ge n Derivatives Chapter 5 El ement s of Group V 173 By N. Logan and D. B. Sower by 1 Nitrogen Elemental Nitrogen Reactions of N2 Complexing of N2 Nitrides Bonds to Hydrogen Ammonia The Ammonium Ion H ydroxylamine Bonds to Nitrogen The N2H2 Molecule H ydrazine Azides General Bonds to Oxygen 173 173 173 175 175 177 177 178 179 179 179 180 180 181 181 ... Vlll Contents Nitrogen($ Species Nitric Oxide Nitrogen(xI1) Species Nitric Acid Nitrates NO,’ Salts NOZ-NZOd Bonds to Fluorine Bonds to Bromine and Iodine 2 Phosphorus Phosphides Compounds containing P-P Bonds Bond to Boron Bonds to Carbon Phosphorus(xI1) Compounds Phosp horus(v) Compounds Bonds to Silicon, Germanium, or Tin Bonds to Halogens Phosphorus(n1) Compounds Phosphorus(v) Compounds Phosphorus(n1) Compounds Phosphorus(v) Compounds Compounds containing P-N Rings Compounds containing Other Ring Systems Compounds of Lower Oxidation State Phosphorus(v) Compounds X-Ray Diffraction Studies Phase Studies Mono-, Di-, and Poly-phosphates Bonds to Nitrogen Bonds to Oxygen Bonds to Sulphur or Selenium 3 Arsenic Arsenides Bonds to Carbon Bonds to Halogens Bonds to Nitrogen Bonds to Oxygen Bonds to Sulphur or Selenium 4 Antimony Antimony and Antimonides Bonds to Carbon Bonds to Halogens Antimony(xI1) Compounds Antimony(v) Compounds Antimony(II1) Compounds Bonds to Oxygen 181 181 182 183 184 184 187 187 187 188 188 188 190 191 191 193 195 196 196 198 200 200 202 205 212 213 213 214 216 216 217 218 220 220 221 222 223 223 225 226 226 227 228 228 229 23 1 23 1 Contents ix Antimony(v) Compounds Bonds to Sulphur 5 Bismuth Chapter 6 Elements of Group VI By M. G. Barker 1 Oxygen The Element Hydrogen Peroxide and Hydrogen-Oxygen Species The Element Sulphur-Halogen Compounds Sulphur-Oxygen-Halogen Compounds Sulphur-Nitrogen Compounds Linear Molecules Polymeric Sulphur Nitride Cyclic Compounds Sulphur-Oxygen Compounds Oxyanions of Sulphur Sulphides Hydrogen Sulphide Polysulphides 0 ther Sulp hides 2 Sulphur 3 Selenium The Element Selenium-Halogen Compounds Selenium-Oxygen Compounds Metal Selenides Other Compounds of Selenium 4 Tellurium The Element Tellurium-Halogen Compounds Tellurium-Oxygen Compounds Tellurides Other Compounds containing Tellurium Chapter 7 The Halogens and Hydrogen By M. F. A. Dove 1 Halogens The Elements Halides Interhalogens and Related Species Oxides, Oxide Halides, and Oxyanions Hydrogen Halides 231 232 233 234 234 234 235 237 237 237 241 242 242 244 245 250 253 255 255 257 257 259 259 259 260 261 263 263 263 264 267 268 270 27 1 271 271 273 276 28 1 284 X Contents 2 Hydrogen Hydrogen-bonding Protonic Acids Miscellaneous Chapter 8 The Noble Gases By M. F. A. Dove 1 The Elements 2 Krypton(n) and Xenon(n) 3 Xenon(rv) 4 Xenon(w) Author Index 286 286 289 290 292 292 292 295 295 297 1 Elements of Group BY P. HUBBERSTEY 1 Introduction The definition of the limits of the literature search pertinent to the present Report is complicated by the extensive role of the alkali metals as simple counter-cations. In general, papers have been abstracted which are relevant to a number of broad subject groups in which the role of the alkali metals is unique. Consequently, the format of this Chapter is such that the inorganic chemistry of the alkali metals is considered collectively in sections which reflect topics presently of interest and importance. For certain topics (e. g. cation solvation, molten salts, crown and cryptate complexes), the chemistry of the Group I and I1 metals is closely ipterwoven; in these cases, the data abstracted are considered once only in the relevant section in this Chapter. The extraction of alkali-metal cations from salt solutions into organic solvents has been the subject of four The ion [.rr-3-1,2-B,C2Hl,]Co- has been proposed as a nearly ideal hydrophobic anion for extraction of M' ions into C,H,NO, uia formation of ion pairs.' Li' has been selectively extracted from nearly neutral aqueous solutions of alkali-metal salts via the formation of the trioctylphosphine adduct of a lithium chelate of fluorinated /3-diketones; although high separation factors were obtained from Na', K', Rb', and Cs+, selectivity from the alkaline-earth-metal cations was found to be poor.* The extraction of M' into PhNO, and MeNO, using hexafluoroacetylacetonate has also been in~estigated.~'~ Dissociation constants of the alkali-metal enolates were deter- mined, the extent of association of enolate ion with enol to give a dimeric ion was deduced, and the latter's formation constant calculated. 2 The Alkali Metals as Solvent Media The role of liquid sodium as a heat-exchange medium in the fast breeder reactor, and that of liquid lithium as a prime candidate far use as the blanket medium in a deuterium-tritium-fuelled thermonuclear reactor, has maintained interest in the solution chemistry of these liquid metals. J. Rais, P. Selucky, and M. Kyrs, J. Inorg. Nuclear Chem., 1976, 38, 1376. * F. G. Seeley and W. H. Baldwin, J. Inorg. Nuclear Chem., 1976, 38, 1049. S. Tribalat and M. Grall, Cornpt. rend., 1976, 282, C, 457. S. Tribalat and M. Grall, Compt. rend., 1976, 282, C, 539. 1 2 Inorganic Chemistry of the Main-Group Elements Phase equilibria for Li-Li3N dilute solutions have been investigated by two independent groups of authors.'-' Pulham et ~1 . ' ~~ have determined the hypoeutectic and hypereutectic liquidi by thermal5 and by electrical resistance6 methods, respectively. The freezing point of Li (453.64 K) is depressed by 0.25 K to 453.39 K at the eutectic composition 0.068 mol YON. The depression was used to calculate the solid solubility of Li,N in Li (0.024molYoN) at the eutectic temperature.' The solubility of Li3N in liquid Li increases smoothly from the eutectic to 2.77 mol % N at 723 K.6 Over a wide temperature range, the data can be represented by equation (1). These latter data are corroborated by those of Veleckis et aL7 [equation (2)], who used a direct sampling technique. This agreement resolves the problem of the earlier inconsistent data' referred to in the previous Report.' Veleckis et uL7 also measured the equilibrium nitrogen pressure over solid Li,N at temperatures between 933 and 1051 K. From a thermodynamic analysis of the solubility and decomposition data, the standard free energy of formation of solid Li3N (AGy/kJ mol-l) was estimated to be 138.9 X T/K - 163.6. For dilute solutions of Li3N in Li, the Sieverts law constant (Ks/atm-1'2= xLi3N P-''~) is given by -13.80+ 14590 (T',K)-'. The melting point of Li,N was found to be 1086 K, in good agreement with the previously reported value of 1088 K.7 10gloXN= 1.168-2036(T/K)-' (473 s T/Ks708) (1) 10g10XL13N = 1.323 - 2107(T/K)-' (468 G T/Ks714) (2) Phase equilibria of Li-LiH and Li-LiD dilute solutions have also been studied by Pulham et a1.5T6~'0*'1 The maximum depression of the freezing point of Li by LiH5 (LiD)" is 0.08K (0.075K), corresponding to a eutectic composition of 0.016 mol%H (0.013 mol% D). These data, which indicate negligible solid solubil- ity of the salts in Li, have been used to show that both hydrogen and deuterium dissolve in liquid Li as monatomic solute species." Typically, the depression caused by small LiH concentrations (Figure 1) follows quite closely the line derived theoretically for monatomic solutes. The theoretical line for a diatomic species is included in the Figure for comparison. The solubilities of LiH6 and of LiD" in liquid Li have been determined by electrical resistance methods at temperatures up to 824 K (5.68 mol%H), and 729 K (2.63 mol%D), and can be represented over a considerable part of the temperature range by equations (3) and (4), respectively. The hydrogen-deuterium isotope effect has been discussed and the experimental data have been extrapolated to predict the behaviour of tritium in liquid Li."." loglOXH= 1.523-2308(T/K)-l ( 523s T/KS775) (3) 10gloxD = 2.321 - 2873(T/K)-' (549 C T/K S 724) (4) P. Hubberstey, R. J. Pulham, and A. E. Thunder, J. C. S. Faraday I, 1976, 72, 431. R. M. Yonco, E. Veleckis, and V. A. Moroni, J. Nuclear Materials, 1975, 57, 317. P. F. Adams, P. Hubberstey, and R. J. Pulham, J. Less-Common Metals, 1975, 42, 1. R. J. Pulham, in 'Inorganic Chemistry of the Main-Group Elements' (Specialist Periodical Reports), ed. C. C. Addison, The Chemical Society, London, 1976, Vol. 4, Ch. 1. lo P. F. Adams, P. Hubberstey, R. J. Pulham, and A. E. Thunder, J. Less-Common Metals, 1976, 46, 285. l 1 P. Hubberstey, P. F. Adams, R. J. Pulham, M. G. Down, and A. E. Thunder, J. Less-Common Metals, 1976, 49, 253. ' P. F. Adams, M. G. Down, P. Hubberstey, and R. J. Pulham, J. Less-Common Metals, 1975,42,325. Elements of Group I r 3 '. -Diatomic soiute species 453955 '\Monatomic solute species 0 0.01 0.02 093 Concenht i on (mol .I. H) Figure 1 Depression of the freezing point of lithium by small concentrations of hydrogen, (Reproduced by permission from J. Less-Common Metals, 1976, 49, 253) showing evidence for monatomic solute species New solubility data for NaH in liquid Na have been determined by Whitting- ham" in a detailed study (610-677K) of the thermodynamic and kinetic properties of the liquid Na-H, system. Comparison with some previous data has been effected and a composite solubility equation (5) formulated. logloxH =1.818 - 3019(T/K)-' (435 4 T/K C 673) ( 5) These new solubility data for hydrogen isotopes have been collated and compared to the corresponding solubilities in NaK and K;l' surprisingly, hydro- gen is least soluble in sodium. Solubility data have been used6'10'11 to determine solvation enthalpies, U,, [defined as in equation (6)] for N3-, 0'-, H-, and D- in Li and for H- in Na and K. The values of U, are collected in Table 1. Those for H- and D- in Li are lower than those for 02- and N3- by factors of ca. 22 and 3', respectively, corresponding to increasing U, with increasing charge of solute. Those for H- in Li, Na, and K are very similar, that in Li being the greatest." Solvation enthalpies have been derived13 in ab initio M.O. calculations of solva- tion clusters in Li and Na. By comparison with experimental data, the best model was deduced to be that of a tetrahedral solvation sphere of cations supplemented by a further metal tetrahedron positioned on the three-fold axes of the first solvation sphere. Other incidental results to emerge from the calculations are the effective radii for Li (0.1675 nm), Na (0.1715 nm), and H (0.0525 nm in Li and Table 1 Solvation enthalpies for non-metal solutes in liquid alkali metals Solvent Potassium Sodium Lithium Lithium Lithium Lithium Solute Hydrogen Hydrogen Hydrogen Deuterium Oxygen Nitrogen UJkJ mol-' -362 -365 -427 -413 -1960 -3473 '* A. C. Whittingham, J. Nuclear Materials, 1976, 60, 119. l3 A. Mainwood and A. M. Stoneham, J. Less-Common Metals, 1976, 49, 271. 4 Inorganic Chemistry of the Main- Group Elements 0.0535 nmin Na) and the effective charges on the H (-0.45 in Li and -0.25 in ~a) . l ~ U X”-(g) -t-MaX”-(M) ( 6) The chemistry of liquid alkali metal-hydrogen solutions has been surveyed.” Whereas hydrogen and nitrogen act independently in Li at 693 K, hydrogen and oxygen interact in Na at 673 K, according to equilibrium (7). Hydrogen-xygen interactions in the other alkali metals are also considered and rationalized in terms of the enthalpy changes of the corresponding solid-state reaction. Further- more, Y has been shown to react with hydrogen in Li at 673 K to form a mixture of Y(H) solid solution and YH, according to reaction (8).11 02- +H- OH- +2e- (7) (8) Li(H) +Y -+Li +Y(H) +YH, Enrichment of deuterium in the gaseous phase above dilute Li-LiD solutions (x, = lop5) has been observed by Ihle and Wu14 at temperatures above 1240 K. This supports the contention that deuterium can be removed from highly dilute solutions in Li by distillation. The results are of importance in the context of the technology of thermonuclear reactors and have been extrapolated to Li-LiT solutions. l4 Several papers pertinent to the elucidation of the corrosive properties of very dilute solutions of non-metals in liquid alkali metals have been p~bl i shed.’ ~-~~ The corrosion of V,15 Nb,15 Ta,15 Mo,16 and W16 plates suspended in dynamic liquid sodium, containing more than 5 p.p.m. oxygen, has been examined at 873 K; the products were analysed through a matrix of Na by X-ray diffraction techniques. The ternary oxides Na,VO, and NaVO, were formed on V, together with a V(0) solid ~olution.~’ For Nb and Ta, only a single ternary oxide Na,MO, (M=Nb or Ta) was observed, together with a M(0) solid Although corrosion of Mo was found to be independent of oxygen concentration, no ternary oxide products being observed, that of W was found to be strongly influenced by initial oxygen concentration in the Na. At low oxygen levels, the cubic phase Na,WO, was identified; at very high oxygen levels in static Na, however, the orthorhombic phase Na6WO6 was observed. Inclusion of labile carbon in the system containing Mo caused the formation of Mo2C.16 The closely related solid-state reaction of Na,O with Mo and W under vacuum gave the ternary phases Na,Mo05 and Na6WO6, respectively, together with unreacted refractory metal and Na vapour.16 Barker and H00per’~have reinvestigated the products of the reaction of liquid Na with CrO, at temperatures up to 873 K; CrO,, Cr203, and Na,CrO, were also studied as substrates. The ternary oxide NaCrO, is found in each case in which reaction took place. The previously accepted reaction product, Na,Cr03, was not formed; the error has been rationalized in terms of the experimental procedure, and improved techniques have been deve10ped.l~Gellings et ~ 1 . ’ ’ have also studied l4 H. R. Ihle and C. H. Wu, J. Phys. Chem., 1975, 79, 2386. l5 M. G. Barker and C. W. Morris, J. Less-Common Metals, 1975, 42, 229. l6 M. G. Barker and C. W. Morris, J. Less-Common Metals. 1976, 44, 169. l7 M. G. Barker and A. J. Hooper, J. C. S. Dalton, 1976, 1093. ’’ H. van Lith, E. G. van den Broek, and P. J. Gellings Znorg. Nuclear Chem. Letters, 1975, 11, 817. Elements of Group I 5 the reaction of CrO, with liquid Na, their results corroborating the identification of NaCrO, as product. The product of these reactions, NaCrO,, together with the other ternary oxides Na,CrO, and Na,CrO,, has been prepared by Barker et ul.19 by the reaction of Na,O and Cr203 or Cr, and it has been characterized by X-ray powder difTraction techniques. NaCrO, decomposes reversibly to the simple oxides at cu. 1068K.l’ The reaction of pure liquid Li with MO, (M=Ti, Zr, Hf, or Th) has been shown to follow thermodynamic predictions.20 TiO, and ZrO, give rise to Li,O and the appropriate transition metal; HfO, yields Hf metal, Li20, and a tet- ragonal phase, which may be the ternary oxide LiHfO,; Tho, does not react. Reaction with liquid Li doped with dissolved nitrogen, however, converts all four oxides, in differing degrees, into either the mononitride or a ternary nitride Li2MN2 (M = Zr, Hf, or Th).20 Liquid K reduces NiO to Ni metal at 458 K with the concomitant formation of the ternary oxides K,NiO, and K,NiO, ; thermomagnetic analysis indicates that the reaction occurs in a single step.21 K2Ni0, was also prepared by the reaction of equimolar quantities of K,O and NiO; K,NiO, was produced by the reaction of K,O and NiO in 0, or by heating K,NiO, in a stream OP 0,. The reaction between Ba and N, in liquid Na has been investigated at 573 K.22923 Solubility studies,, showed that the reaction of a 4.40mol YO Ba solution occurs in two stages; (i) dissolution of N2 (N, is insoluble in pure liquid Na), and (ii) precipitation of Ba,N, the initial product of the reaction. The occurrence of these two processes is reflected in the resistivity studies2, effected on a number of Na-Ba solutions (between 0.34 and 6.89 mol YO Ba). The extent of the solution process was found to be a linear function [equation (9)] of the initial Ba concentration, the solubility limit corresponding to an overall reaction com- position approximating to Ba,N. This ratio, and the decrease in resistivity which invariably occurred during the solution process, leads to the concept of strong preferential solvation of the nitride ion by Ba cations, perhaps in the form of a ‘Ba,N’ solvated unit.,, xN = 0 . 2 5 ~ ~ ~ (0 < xBa < 0.0689) (9) The reaction of C,H, with liquid K has been studied in the range 503-671 K.,, At low temperatures, self -hydrogenation occurs precisely according to equation (10). The surface reaction is explained by dissociative adsorption of C2H4 into H adatoms, which are subsequently employed in hydrogenation. With increasing temperature, progressively less C2H6 is produced, which is attributed to the loss of H from the surface by solution in the metal.,, l9 M. G. Barker and A. J. Hooper, J. C. S. Dalton, 1975, 2487. 21 M. G. Barker and A. P. Dawson, J. Less-Common Metals, 1976, 45, 323. 22 C. C. Addison, R. J. Pulham, and E. A. Trevillion, J. C. S. Dalton, 1975, 2082. 23 C. C. Addison, G. K. Creffield, P. Hubberstey, and R. J. Pulham, J. C. S. Dalton, 1976, 1105. 24 G. Parry and R. J. Pulham, J. C. S. Dalton, 1975, 2576. M. G. Barker, I. Alexander, and J. Bentham, J. Less-Common Metals, 1975,42, 241. 20 6 Inorganic Chemistry of the Main-Group Elements 3 Metallic Solutions and Intermetallic Compounds The nature of the bonding in intermetallic phases has been and an attempt has been made to demonstrate qualitatively the dependence of both the number of phases in a binary system and their relative thermal stabilities on the electronic configurations of the component atoms. Particular attention has been devoted to compounds of the alkali metals with Hg,25 Sn,26 Pb,25 Sb?' and BiZ5 The preparation of the novel compounds K2Cs and K7Cs6 by precipitation from solid K-Cs solutions at temperatures below 183 K has been reported.27 Structural analysis has shown that K2Cs (a = 0.9065, c = 1.4755 nm at 178 K) is isotypic with the hexagonal Laves phase Na2K, whereas K7Cs6 ( a = 0.9078, c = 3.2950 nm at 178 K) forms hexagonal crystals with a novel kind of Frank-Kasper structure. Although the K atoms in K7Cs, are sited in two 12-co-ordination polyhedra, the Cs atoms occupy one of four sites with 14-fold, 15-fold (X2), and 16-fold co-ordination. The K * - K, Cs - - Cs, and K - - - Cs distances vary from 0.454 to 0.461, from 0.501 to 0.546, and from 0.466 to 0.5741m.~~ The Li-In phase diagram has been exhaustively re-examined by Alexander et ~ l . , ' ~ using thermal and X-ray diffraction analysis. The work has confirmed the liquidus data of Grube and Wolf29 and delineated .the solid-state relationships. Eleven new phases (Table 2), together with the previously known LiIn phase (which extends from ca. 46 to between 55 and 63 mol% Li, depending on temperature), have been observed. The discovery of new phases, of which only five are stable at room temperature, has removed the apparent anomaly between the Li-In and the Li-Ga and Li-Tl systems. The solid solubility of Li in In is low (ca. 1.5 mol O h Li at 432 K) and that of In in Li is very Intermetallic phases of the Li-Pd3' and Li-Pt31 systems have been synthesized Table 2 Intermetallic phases of the Li-In system2' Phase Model Cornpositionlmol % Li Phase transformation fomula derived observed temperatures (approx.)/K LiIn 50.0 46.5-63.0 - 903" Y Li71n, 63.6 63.6 - 583' P s Li21n 66.7 66.8 - 743' & Li51n2 71.5 71.8 353d 670' Li,In, 72.8 71.9 - 353' 5 rl Li731n27 e Li,,In, 73.4 L Li,In 75.0 75.8 - 686" K Li,In 80.0 80.7 - 583' I.L Li61n 85.7 85.5 39gd 573" Y LiJn 92.3 92.6 413d 533" - 61gd 698" - 60gd 658b 73.0 A Li,In 80.0 80.7 583" 673' a Melting point; peritectoid decomposition; peritectic decomposition; eutectoid formation; phase transformation " V. I. Kober and I. F. Nichkov, Russ. J. Phys. Chem., 1975,49, 829. 26 V. I. Kober and I. F. Nichkov, Russ. J. Phys. Chem., 1975, 49, 962. A. Simon, W. Bramer, B. Hillenrotter, and H.-J. Kullman, 2. anorg. Chem., 1976, 419, 253. '* W. A. Alexander, L. D. Calvert, R. H. Gamble, and K. Schinzel, Canad. J. Chem., 1976,54,1052. 29 G. Grube and W. Wolf, 2. Electrochem., 1935, 41, 675. 30 J. H. N. van Vucht and K. H. J . Buschow, J. Less-Common Metals, 1976, 48, 345. 31 W. Bronger, B. Nacken, and K. Ploog, J. Less-Common Metals, 1975, 43, 143. 27 Elements of Group I 7 and their structures elucidated; pertinent structural data for seven Li-Pd phases (including Li,Pd and LiPd), as determined in X-ray diffraction studies, and for Li,Pt and LiPt, as determined using neutron-diflraction techniques, are collected in Table 3. Table 3 Pertinent structural parameters for intermetallic phases in the li-Pd and Li-Pt systems Phase Space group Structure type alnm clnm Ref. LiPd, Fm3m LiPt, 0.7660 - 30 LiPd, hexag. P - LiPd" P6 LiRb LiPd Pm3m CSCl Li,Pd P6Immc AIB, Li,Pd Fm3m BiF, Li,,Pd, 143d Cu,,Si, Li, Pd" (6 < x < 10) cubic LiPt hexag. - Li,Pt - AlB, a LiPd and Li,Pd exhibit wide homogeneity ranges - 0.3836 0.2977 0.4227 0.6187 1.0676 1.9009 {1.9347 0.2728 0.4186 0.4336 30 0.4280 30 0.4131 30 - 30 0.2732 30 30 30 30 30 0.4226 31 0.2661 31 - - - - Thermodynamic properties of liquid Li-T132 and of liquid Na-X33 (X = Cd, Hg, In, TI, Sn, Pb, Sb, Bi, S, Se, or Te) have been studied. The unsymmetrical form of the nature of the dependence on concentration of the thermodynamic charac- teristics of the Li-TI system, which exhibits negative deviations from Raoult's Law, is thought to be consistent with the equilibrium diagram.32 The dependence on concentration of the entropy of mixing in the Na-X systems is S-shaped, the point of inflexion corresponding to formation of intermetallic This behaviour is attributed to a high degree of short-range order in the liquid, and of partial ionic character of the bonds in these intermetallic compounds. Short-range order has also been studied in liquid Li-Pb solutions by neutron-diffraction techni q~es.~~ The data indicate a preference for unlike nearest neighbours; this is manifest in a reduction of distance between unlike neighbours (0.295 nm) as compared with the mean distances between the pure components (Li - - * Li = 0.300 nm; Pb - - - Pb = 0.340 nm). It has been suggested that the short-range order is probably due to salt-like Li - - - Pb bonding. No evidence for the existence of isolated LLPb clusters was obtained; indeed, in liquid Li,Pb, each Pb atom is surrounded by ca. 10 Li atoms.,, 4 Solvation of Alkali-metal Cations The majority of data published on the solvation (both aqueous and non-aqueous) of alkali-(and alkaline-earth-)metal cations is of but peripheral interest to the inorganic chemist. Consequently, the papers abstracted for this section of the Report are quite selective, dealing principally with the structural and spectros- copic properties of these solutions. 32 S. P. Yatsenko and E. A. Saltykova, Russ. J. Phys. Chem., 1975, 49, 292. 33 A. G. Morachevskii, E. A. Maiorova, and A. I. Demidov, Russ. J. Phys. Chem., 1975, 49, 1093. 34 H. Ruppersberg and H. Egger, J. Chem. Phys., 1975, 63, 4095. 8 Inorganic Chemistry of the Main- Group Elements As a starting point in a theoretical study of ionic solutions, the complex H,O- Li'-F has been ~onsi dered.~~ Analysis of the stabilization energies of some 250 geometrical configurations reveals the existence of at least three possible struc- tures: (i) the Li-F-H,O structure that has C,, symmetry; (ii) a second Li-F-H,O structure with the F forming a hydrogen bond (with a hydroxy-group); and (iii) the F-Li-H20 structure that has C,, A model for an ion immersed in a dielectric medium as a spherical charge surrounded by a region of dielectric gradient has been applied to structured solutions of strong binary electrolyte^.^^ In the case of alkaline-earth-metal halides and nitrates, the results show excellent agreement with experimental data up to concentrations of 2 or 3 mol l-1.36 Changes in cation polarizability observed on hydration have been described by a model which attributes the changes solely to solvent pert~rbati on.~~ Hydration structures for alkali-metal cations have been generated from the results of a number of energy ~al ~~l at i on~. ~~ For Li' and Na' a tetrahedral inner solvation sphere is the most stable configuration. For K+, Rb', and Csf, the energy differences between structures are so small that it is impossible to predict with certainty the most stable c~nfiguration.~' CND0/2 calculations have also been effected for solvation of, inter a h , Li' and Na', by MeOH.39 The results are compared with experimental data (only partial agree- ment is achieved) and with similar calculations for solvation by water. Thermo- dynamic functions for hydration of alkali-metal cations have also been deter- mined: and the effects of solvation on the conductivity of concentrated electro- lyte solutions studied theoretically and e~perimentally.~~ The structures of these ionic solutions have been studied, using X-ray difb-ac- tion,42*43 n.m.r.,4448 and ultrasonic49 techniques. X-Ray diffraction measure- ments of aqueous NaI showed that the Na' ion is bonded to cu. four water molecules at a Na'. - - 0 distance of ca. 0.24 nm. Similar experimental data for aqueous CaBr, can be rationalized with both six- and eight-fold co-ordinate Ca2+ions. In both solutions, the halide ion is approximately octahedr- ally co- ~rdi nated.~~'~~ of aqueous LiIO, solutions containing added iodic acid or iodates have established that, up to concentrations of LiI 03 of 3 mol l-l, the 10, ion does not substitute in the first hydration shell of the Li' ion. Studies of 7Li n.m.r. relaxation 35 J. W. Kress, E. Clementi, J. J. Kozak, and M. E. Schwartz, J. Chem. Phys., 1975, 63, 3907. 36 L. W. Bahe and D. Parker, J. Amer. Chem. SOC., 1975, 97, 5664. 37 H. Coker, J. Phys. Chem., 1976, 80, 2084. 38 K. G. Spears and S. Y. Kim, J. Phys. Chem., 1976, 80, 673. 39 M. Salomon, Canad. J. Chem., 1975, 53, 3194. 40 R. Jalenti and R. Caramazza, J. C. S. Faruday I, 1976, 72, 715. 41 D. E. Goldsack, R. Franchetto, and A. Franchetto, Canad. J. Chem., 1976, 54, 2953. 42 M. Maeda and H. Ohtaki, Bull. Chem. SOC. Japan, 1975, 48, 3755. 43 G. Licheri, G. Piccaluga, and G. Pinna, J. Chem. Phys., 1975, 63, 4412. L. A. Arazova, N. V. Bryushkova, E. E. Vinogradov, I. M. Karataeva, and R. K. Mazitov, Russ. J. Inorg. Chem., 1976, 21, 3. 44 45 W. J. deWitte, R. C. Schoening, and A. I. Popov, Inorg. Nuclear Chem. Letters, 1976, 12, 251. 46 J. W. Akitt and R. H. Duncan, J. C. S. Furuday I, 1976, 72, 2132. 47 L. Simeral and G. E. Maciel, J. Phys. Chem., 1976, 80, 552. 48 M. C. R. Symons, Spectrochim. Actu, 1975, 31A, 1105. 49 G. A. Ivashina, T. S. Kuratova, M. 0. Tereshkevich, and V. G. Korovina, Russ. J. Phys. Chem., 1975, 49, 1185. Elements of Group I 9 Cs n.m.r. data4’ for caesium salts in H,O and in various non-aqueous solvents have been interpreted in terms of the formation of contact ion-pairs, even in polar solvents of high donicity. The large radius and concomitant low charge/surface ratio of Cs’ make it a poorly solvated ion, and caesium salts are more liable to form ion pairs than are Li’ or Na’ ’H n.m.r. data for aqueous solutions of Be(NO,), and BeCl, have been interpreted46 as arising from rapid proton exchange between bulk H20 and H,O in three ionic environments: (i) the cationic complex Be(H,O):’, (ii) a second hydration sphere oriented by the electric field of the cation, and (iii) H,O near the anions. It has been suggested that the fact that a known tetrahydrated cation, Be(H,O):+, gives results which are consistent with a primary co-ordination number of 4 is a key result, and that it gives strong support to the contention, based on similar results for M’ ions, that these are also tetrah~drated.~~ Unfortu- nately, in a related 2sMg F.T. n.m.r. study47 of aqueous solutions of magnesium salts, it was found to be impossible to predict, a priori, the relative importance of the solution structures considered. The effect of temperature and of added aprotic solvents (e.g. MeCN) on the ‘H n.m.r. spectra of H,O and MeOH solutions containing Mg” (and A13’) have been a~certai ned.~~ The data are thought to be indicative of strong secondary solvation, effected principally via hydrogen bonding, but with a small contribution from the electrostatic effect. An ultrasonic study of aqueous solutions of alkaline-earth-metal salts has been ~ndertaken.~~ The observations suggest that the stability of the solvated structures depends on the capacity of the ions for hydration and complex formation, their dimension, and their shape. Ionic solvation in H,O+cosolvent mixtures has been the subject of a num- ber of recent ~~mmuni ~ati on~. ’ ~- ~~ Cosolvents have included acetone,” form- amide,’* NN-dirnethylf~rmamide,’~ NN-dimethyla~etamide,’~t-butyl alcoh01,’~ and dioxan.” Interpretation of ‘H n.m.r. data (173-303 K) for solutions of Be(N03), in aqueous acetone solutionsso has shown that Be2+is present mainly in the form of tetra-aquo complexes, coexisting with (probably) polymerized hydroxo(oxo)diaquo complexes. The existence of the tetra-aquo complex has been confirmed by analyses of ”0 n.m.r. spectra of aqueous Be(NO,), The formation of solvated cationic species in H20 i- formamide (Na+)’l and H20 + DMF (Li+, Na+, K+)52 mixtures has also been investigated in a study of the viscosities of these solutions. The interaction of lithium salts with dilute H,O+ DMA mixtures has been studied, using 13C n.m.r. technique^;'^the results have been interpreted in terms of the transient species Li’(H,O),DMA and Li+(H20)5DMA. Thermodynamic parameters for the transfer of alkali-metal salts from H20 into HzO + t-butyl alcohol (MCl; M = Li, Na, K, Rb, or CS) ’ ~ and into H,O + dioxan (LiC1, NaCl, CsI)’’ mixtures have been ascertained. Similar ther- modynamic data for the transfer of, inter a h , BaZ+from H,O into methanol, 133 50 V. A. Shcherbakov and 0. G. Golubovskaya, Russ. J. Inorg. Chem., 1976, 21, 28. 51 J. M. McDowall, N. Martinos, and C. A. Vincent, J. C. S. Faraday I, 1976, 72, 654. *’ B. N. Prasad, N. P. Singh, and M. M. Singh, Indian J. Chem., 1976, 14A, 322. 53 M. J. Adams, C. B. Baddiel, G. E. Ellis, R. G. Jones, and A. J. Matheson, J. C. S. Faraday 11, 1975, 71, 1823. 54 C. F. Wells, J. C. S. Faraday I, 1976, 72, 601. 55 D. Feakins and C. T. Allan, J. C. S. Faraday I, 1976, 72, 314. 10 Inorganic Chemistry of the Main-Group Elements R R I (b) H H 1 : (a) generally a methyl group Figure 2 Solvation shells about M2+ in (a) water and (b) dipolar aprotic solvents; R is (Reproduced by permission from J. Amer. Chem. SOC., 1975, 97, 3888) hexamethylphosphoramide, acetonitrile, DMF, and DMSO have been deter- mined.56 It has been noted that divalent cations have more than one layer of solvent molecules in their solvation shells, for most of the solvents studied. Whereas hydrogen bonding is thought to be the mechanism whereby hydration shells are built up, extension to secondary shells in the case of dipolar aprotic solvents is possible only through alternative and weaker mechanisms, such as enhancement of the induced dipoles in the first solvation shell. A pictorial representation of these two schemes for solvation of M2+ ions is shown in Figure The ‘effective’ solvation numbers (i.e. total number of moles of solvent solvated to one mole of solute) of NaI, KI, LiN03, LiClO,, L X (X=Cl, Br, or I), and CaCl, and of LiC1, LiBr, LiN03, and LiC104 in MeOH have been deduced from ‘H n.m.r. studiess7 and conductivity experiment^,^^respectively. The solvation numbers are quite similar to hydration numbers; this observation is accepted as evidence that both solvents bind primarily through the oxygen atom of the solvent and not the hydroxyl proton. Furthermore, it is thought that the positive ion is more highly solvated than the negative ion, and that M2+ ions are more effectively solvated than M’ ions.57 The conductivities of MClO, (M=Na, K, Rb, or Cs) in ethylene glycol have been determined and the temperature coefficients of their mobilities estimated;” the analysis of the data shows that the M’ ions are strongly solvated. Observa- tions noted in studies of the viscosities of solutions of MI (M = Li, Na, K, Rb, or Cs) in DMSO also indicate that solvation of M’ is important in this 2.56 56 G. R. Hedwig, D. A. Owensby, and A. J. Parker, J. Amer. Chem. Soc., 1975, 97, 3888. 57 F. J. Vogrin and E. R. Malinowski, J. Amer. Chem. SOC., 1975, 97, 4876. ” P. A. Skabichevskii, Russ. J. Phys. Chem., 1975, 49, 100. 59 R. Fernandez-Prini and G. Urrutia, J. C. S. Faraday I, 1976, 72, 637. 6o R. Gopal and P. Singh, Indian J. Chem., 1976, 14A, 388. Elements of Group I 11 The effect of triethanolamine (TEA) on the conductances of solutions of alkali-metal 2,4-dinitrophenolates in THF has been ascertained;6' the observed increase in conductivity in the presence of the TEA has been interpreted as due to formation of cation-ligand and ion pair-ligand complexes. The structures of the M'-TEA complexes (1) are assumed to be similar to that found in the Na' solid-state complex; the three hydroxyethyl groups of the TEA are envisioned to form a pocket of Lewis-base cations which can accept and surround the M' ions.61 0-f (1) 1.r. and 'H n.m.r. spectra of HDO and of MeOH, at low concentration in MeCN, propylene carbonate, 1,1,3,3-tetramethylurea, and NN-dimethyl- formamide containing various salts [LiClO,, LiBr, Sr(C104)2, Ca(SCN),], have been determined at 308 f 2 K.62 The results suggest the presence of solvent- bonded, cation-bonded, anion-bonded, and solvent-shared or solvent-separated ion complexes.62 5 Simple Compounds of the Alkali Metals This section deals principally with binary derivatives of the alkali metals; ternary compounds are omitted since they are considered, as appropriate, either elsewhere in this Report or in that covering the inorganic chemistry of the transition metals.63 Included here are subdivisions relating to hydrides, oxides and related species, and halides. Compounds of Group IV and V non-metals are not discussed because of the paucity of data. A separate section, entitled 'Molten Salts', dealing with the chemistry of molten halides (and nitrates) as solvents, is also included. Hydrides.-Several papers describing theoretical analyses of alkali-metal hydride molecules have been The applicability of potential-energy func- tions for these molecules has been examined? and the mixing of ionic and covalent configurations for NaH, KH (and MgH') Possible low- energy paths for the formation of the Li - - - H bond have been and the spectroscopic properties of, inter alia, LiH calculated.68 The preparation of NaH has been the subject of two communications.69~70 The H. B. Flora and W. R. Gilkerson, J. Phys. Chem., 1976,80,679. 62 I. D. Kuntz and C. J. Cheng, J. Amer. Chem. Soc., 1975, 97,4852. 63 'Inorganic Chemistry of the Transition Elements', (Specialist Periodical Reports), ed. B. F. G. 64 M. M. Pate1 and V. B. Gohel, Spectrochim. Acra, 1975, 3% 855. 65 R. W. Numrich and D. G. Truhlar, J. Phys. Chem., 1975, 79, 2745. 67 R. Datta, Indian J. Chem., 1976, 1 4 4 269. 6a A. M. Semkow and J. W. Linnett, J. C. S. Faraday Ll, 1976, 72, 1503. 69 J. Subrt, P. Kriz, J. Skrivanek, and V. Prochazka, Coll. Czech. Chem. Comm., 1975, 40, 3766. 70 V. Prochazka and J. Subrt, Coll. Czech. Chem. Comm., 1976, 41, 522. Johnson, The Chemical Society, London. W. B. England, N. H. Sabelli, and A. C. Wahl, J. Chem. Phys., 1975, 63,4596. 12 Inorganic Chemistry of the Main-Group Elements product of the simplest synthetic route (direct reaction of the elements at increased pressure and temperature in a rotating autoclave) is a sintered substance of low reactivity, contaminated with Na, and being of stoicheiometry NaH,.,.69 In the presence of catalysts (e.g. R,CHCHO, R,CHCR,OH, R,CHCHROH, and K,CHCO,H), however, a product of stoicheiometry NaH and of large specific area is ~btai ned.~* The kinetics of the uncatalysed reaction (conditions: 5- 40 atm, 543-613 K) have been elucidated, and an apparent activation energy of 54.27 kJ mol-' has been determined.69 Oxides, Hydroxides, Sulphides, etc-The chemistry of rubidium and caesium suboxides has been studied by Simon and co- w~rkers.~~- ~~ The preparation and crystal growth of Rb6O;l Rbg02,71 cs70,72 and CS,O~~ has been described. The exact formula, [Rb902]Rb3, and structure of Rb60 have been derived from single-crystal data, the crystals being grown at temperatures below 265 K in a Weissenberg camera.71 The characteristic [Rb902] units (Figure 3a), in which the oxygen atoms are octahedrally co-ordinated, occur as in Rb902 itself, alternating with layers of metallic Rb. Similar structural chemistry is observed in the caesium suboxides, in which the [Csl1O3] unit (Figure 3b) is a recurrent moiety; thus, low-temperature (103,253 K, 243 K, C S ~O~~) single-crystal X-ray diffrac- tion studies show that the structures of Cs70 and @s,O correspond to the formulae [CsllO,]Csl, and [Cs,,O,]Cs, respectively. In Cs,O, the [Csl103] clus- ters, in which the oxygens are again octahedrally co-ordinated (Figure 3b), form a n Oxygen 0 Rubi di um, Caesi um Figure 3 Schematic representations of (a) the Rb,O, moiety in Rb,O, and (b) the Cs,,O, [Reproduced by permission from (a) Reu. Chim. minerale, 1976, 13, 98, and (b) 2. anorg. moiety in Cs,O Chem., 1976, 423, 2031 71 A. Simon and H.-J. Deiseroth, Rev. Chim. minerale, 1976, 13, 98. 72 A. Simon, Z. anorg. Chem., 1976, 422, 208. 73 A. Simon, H.4. Deiseroth, E. Westerbeck, and B. Hillenkotter, 2. anorg. Chem., 1976, 423, 203. 74 G. Ebbinghaus, W. Braun, and A. Simon, 2. Naturforsch., 1976, 31b, 1219. Elements of Group I 13 hcp arrangement, the single Cs atoms occupying the quasi-octahedral sites of this arrangement, as in the case of NiAs7, UPS [He (I)] data for the suboxides Cs1103, [ CS~~O~] CS~~, and [Cs1103]Rb7 have been determined at 98*5 K.74 Extremely narrow oxygen 2p levels are observed (Table 4) as well as significant differences in the binding energies of the 5p levels of chemically different Cs atoms. The results are rationalized in terms of the structurally derived bonding models discussed above.74 Table 4 Binding energieslev in alkali-metal s~boxi des~~ Compound Binding energies Rb - 15.2 16.1 c s - - - 12.1 14.0 13.2 14.0 13.1 cs1103 2.7 - - 11.6 13.3 [CsiiO,]Rb O(2p) Rb(4p312) Rb(4p112) Cs(5p312) C~( 5pl ’ ~) - - - {:::: [c~iio~1c~io 2.7 - 2.7 15.3 16.2 11.5 The standard enthalpy of formation of Li,O, AHf)(Li,O,c,298.15 K) has been calculated to be (-597.9 f 0.3) kJ mol-’ in a determination of the enthalpy of reaction of Li,O with H,0.7s An abortive attempted synthesis of Li(0,) [and of Ca(O,),], involving the oxidation of LiOH [Ca(OH)2] in a low-pressure discharge, sustained in oxygen, has been reported;76 the sole products of the reaction were Li,O, (CaO,). of the melting temperatures of K,O (1013 K), KO, (778 K), and K202 (818K), as well as the crystalline transition (dimorphous /3- tetragonale P-NaC1 type cubic) temperature of KO2 (425 K), has been under- taken, using fritted CaO crucibles. The crystal symmetries of the two KO, modifications, of K2 0 (cubic anti-CaF,), and of K202 (orthorhombic) were confirmed by X-ray diffraction techniques.77 The melting temperature of KO2 has also been determined in a study of the KO2-KNO, phase diagram.78 The experimentally determined value for commercial KO, (773 f 1 K) was corrected for assumed KOH impurities (xKOH=0.045) to give an a posteriori value of (784f2) K. The KO,-KNO, phase diagram is a simple eutectic system, with eutectic temperature and composition 495 f 1 K and 34 mol % KO,, respectively. Spectroscopic studies of Li(OH),H,O (i.r.),79 Li(OD),D,O (i.r.?’ ,H n.m.r.80), and M(OH),nH,O (M = Rb or Cs; n = or 1) (i.r.)79 have been effected. Interpre- tation of the i.r. data for Li(OH),H,O is said to confirm the presence of co-ordinated H20 and OH- ion. The H,O and OH- ions in Li(OH),H20 form discrete, planar, hydrogen-bonded [(OH-),(H,O),] anionic units, rather than the extended chains observed in other alkali-metal hydroxide hydrates. The ,H n.m.r. study (82K) of Li(OD),D,O has shown that the crystal is ordered. The OD- points along the c-axis of the crystal and the plane of the D20 molecule is A d.t.a. 75. G. K. Johnson, R. T. Grow, and W. N. Hubbard, J. Chem. Thermodynamics, 1975, 7, 781. 76 P. Sadhukan and A. T. Bell, J. Inorg. Nuclear Chem., 1976, 38, 1570. 77 A. deKozak, J.-C. Bardin, and A. Erb., Reu. Chim. minerale, 1976, 13, 190. 78 J. M. deJong and G. H. J. Broers, J. Chem. Thermodynamics, 1976, 8, 367. 79 I. Gennick and K. M. Harmon, Inorg. Chem., 1975, 14, 2214. J. 0. Clifford, J. A. S. Smith, and F. P. Temme, J. C. S. Faraday II, 1975, 71, 1352. 14 Inorganic Chemistry of the Main- Group Elements perpendicular to the same direction, giving rise to strong but markedly non-linear hydrogen bonds between the two species.*o The phase relationships between MOH (M=Li, Na, or K) and Ba(OH), have been elucidated.*l Although Ba2’ ions cannot be inserted in the LiOH lattice, their penetration into those of NaOH and KOH is facile, the probability of insertion being greater with KOH. Conversely, the probability of insertion of alkali-metal cations into Ba(OH), is low. In all three systems, an intermediary, non-stoicheiometric phase with composition close to MOH,2Ba(OH), (M = Li, Na, or K) is formed.81 Alkali-metal polysulphides have been the subject of a number of recent publications.82-86 The central theme of most of these papers is the polysulphide anion; hence the data will not be considered in detail in this Chapter. Halides.-Theoretical calculations have been performed on both alkali-metal halide m01ecul es~~~~~ and cry~tals.~’-’~In an analysis87 of the dipole moments of alkali-metal halide molecules, the extent of effective charge transfer was found to vary from 0.76 (LiI) to 0.99 (CsF), in an order that is predictable from the Periodic Table. Expressions for the force constant, i.r. absorption frequency, Debye tempera- ture, cohesive energy, and atomization energy of alkali-metal halide crystals have been ~btained.~’”~ Gaussian and modified Gaussian interatomic functions were used as a basis; the potential parameters were evaluated, using molecular force constants and interatomic distances. A linear dependence between spectroscopi- cally determined values of crystal ionicity and crystal parameters (e. g. interatomic distances, atomic vibrations) has been observed.” Such a correlation permits quantitative prediction of coefficients of thermal expansion and amplitude of thermal vibrations of the atoms. The temperature dependence (295-773 K) of the atomic vibrations for NaF, NaCl, KC1, and KBr has been determined,92 and molecular dynamics calculations have been performed on LiI and NaC1.93 Empiri- cal values for free ion polarizabilities of alkali-metal, alkaline-earth-metal, and halide ions have been obtained from static crystal polarizabilities;94 the results for the cations are in agreement with recent experimental and theoretical work. The adsorption of H,O on a variety of alkali-metal halide crystals has been studied by i.r. and far4.r. spectro~copy.’~For the majority of halides (typically 81 M. Michaud, G. Ado, and G. Papin, Bull. Soc. chim. France, 1975, 1479. 82 J.-M. Letoffe, J.-M. Blanchard and J. Bousquet, Bull. SOC. chim. France, 1976, 395. 83 H. H. Eysel, G. Wieghardt, H. Kleinschmager, and G. Weddigen, Z. Naturforsch., 1976,31b, 415. 84 G. J. Janz, J. W. Coutts, J. R. Downey, and E. Roduner, Inorg. Chem., 1976, 15, 1755. G. J. Janz, J. R. Downey, E. Roduner, G. J. Wasilczyk, J. W. Coutts, and A. Eluard, Inorg. Chem., 1976,15, 1759. 85 86 B. Kelly and P. Woodward, J. C. S. Dalton, 1976, 1314. g7 R. L. Matcha and S. C. King, J. Amer. Chem. Soc., 1976, 98, 3420. 89 K. P. Thakur and L. Thakur, Indian J. Chem., 1976,14A, 97. 90 K. P. Thakur, J. Inorg. Nuclear Chem., 1976, 38, 1433. 91 S. Deganello, Z. Krist., 1975, 142, 186. 92 S. DeganeUo, Z. Krist., 1975, 142, 45. 93 J. Michielsen, P. Woerlee, F. van den Graaf, and J. A. A. Ketalaar, J. C. S. Faraday II, 1975, 71, 94 H. Coker, J. Phys. Chem., 1976, 80, 2078. 95 R. St. C. Smart and N. Sheppard, J. C. S. Faraday II, 1976, 72, 707. K. B. Hathaway and J. A. Krumhansl, J. Chem. Phys, 1975, 63, 4313. 1731. Elements of Group I 15 NaCl), two surface H20 species are inferred: (2) involves hydrogen bonding of both hydroxyl bonds to halide ions whereas (3), which occurs at higher coverages, involves hydrogen bonding of one hydroxy-group only to halide ions. Lithium salts exhibit only (2) at all coverages up to mon01ayer.~~ The adsorption potential of H, and of N, on the [loo] plane of a distorted NaCl lattice has also been investigated .96 0 /" I H Cl- Na' Cl- Cl- Na+ Heats of mixing of solid solutions of CsCl with CsBr, KCl, and RbCl have been obtained by precise aqueous solution ~alorirnetry.~' Results show evidence for the abrupt stabilization of the NaCl (Fm3rn) structure with respect to the CsCl (Pm3rn) structure in the Cs,-,K,Cl and Cs,_,Rb,Cl systems at molar ratios corresponding to x = 0.25 (Cs,_,K,Cl) and x = 0.50 (CS,-,R~,C~).~' CsBr, has been prepared in high purity; its enthalpy of formation, AH, (CsBr,,c), has been determined by solution calorimetry to be -433.8 f 2.0 kJ rn~l - ~. ~' Using ionic models, the energies (and entropies) of a number of configurations of M& (M = Li or Na) ions have been ~al cul ated.~~ The most stable configuration is that with a linear arrangement of atoms (Dmh); the calculated entropy for this configufation agrees with the experimental value. Molten Salts.-Interest in the solution chemistry of molten salts (of both alkali- metal and alkaline-earth-metal cations) has been maintained during the period of this Report; as in previous Reports, the majority of the abstracted data describes aspects of the chemistry of halide and nitrate melts. Halides. I n a study of emulsions in molten salts, the concentration and particle size distribution of dispersed Li in molten LiCl have been examined;"' the influence of Li20 and of Li,N has also been considered. The solubility of I2 in fused MI (M = Li, Na, K, or Cs) has been determined."' Analysis of the results shows that M+cations, I2 molecules, and I- and 13 anions are present, the proportion of 1; increasing in the sequence KI < RbI < CsI. The solubility of MgO in fused MC1 (M=Na, K, Rb, or Cs),lo2 of TiO, in fused MCl, (M=Mg, Ca, or Sr),lo3 and of MOCl (M = Y, La, or Nd) in MC12 (M = Mg, Ca, Sr, or Ba)lo4 has been measured. The hypothesis that the dissolution mechanism for the MgO-MCI solutions 96 A Ben Ephraim and M. Folman, J. C. S. Furuday 11, 1976,72,671. 97 A. K. Shukla, J. C. Ahluwalia, and C. N. R. Rao, J. C. S. Furaduy I, 1976,72,1288. 98 L. R. Morss, J. Chem. Thermodynamics, 1975, 7, 709. * A. V. Gusarov, Russ. J. Phys. Chem., 1975, 49, 1576. loo T. Nakajima, K. Nakanishi, and N. Watanabe, Bull. Chern. SOC. Japan, 1976, 49, 994. lo' L. E. Ivanovskii, W. N. Nekrasov, V. S. Mironov, and V. A. Biryukov, Russ. J. Phys. Chern., 1975, 49, 1233. T. L. Inyushkina, L. P. Petukhova, and V. T. Kornilova, Russ. J. Inorg. Chern., 1975, 20, 594. lo3 T. L. Inyushkina, I. N. Marenkova, and L. N. Dzyubo, Russ. J. Phys. Chern., 1975, 49, 1446. ' 04 P. G. Permyakov, B. G. Korshunov, and V. A. Krokhin, Russ. J. Inorg. Chern., 1975, 20, 1213. 16 Inorganic Chemistry of the Main-Group Elements involves physical introduction of MgO into the free space in the melt structure has been advanced.", The extent of solubility in Ti02-MC12 solutions is found to be almost an order of magnitude greater than in the corresponding alkali-metal halides (with the exception of LiC1).lo3 Calorimetric data have been obtained for a number of fused salt systems.'0s-108 The enthalpies of mixing of LiF-NaF, NaF-KF, LiF-KF (all at 1360K), and of LiF-KF (at 1176 K) mixtures have been redetermined by Kleppa et aZ.los by a direct mixing technique. The results are in reasonable agreement with values previously reported by Kleppa et aLio9 and by Gilbert,'" but differ considerably from the recent data of MacLeod and Cleland."' Enthalpies of formation of NaCl-MgCl,, KC1-MgCl,, and NaC1-KC1-MgCl, mixtures have been determined calorimetrically;lo6 standard enthalpies of formation of the compounds KCl,MgCl, (-9.04k 0.46 kJ mol-') and 2NaC1,MgC12 (5.44 f 0.88 kJ mol-l) have been derived. A physicochemical study (1193-1650 K)ll2 of KC1-MgC12 melts has shown that vapour-pressure isotherms are of limited use in establishing the complexes present in the liquid phase. A semi-quantitative model, based on the assumption of dissociated complex species in the melt, has been developed to aid interpretation of experimental enthalpies of mixing of molten sa1ts.'O7 Comparison of estimated equilibrium constants and enthalpies of formation of the complex species (typically LaClg- and GdCg-) present in the solutions (KC1-LaCl,, CsCl-GdCl,) with experimental data for the corresponding solid-state compounds (K,LaCl,, Cs,GdCk) shows satisfactory agreement. Data for the enthalpy of mixing of LiF-ZnF, (1273 K), NaF-ZnF, (1279 K), and KF-ZnF, (1232,1325 K) liquid mixtures indicate that the principal anionic complex in these systems is ZnK or possibly a polymer of this composition.108 Evidence has also been put forward for the presence of FeCl,, Fe2C1;, and Fe,C16 in a potentiometric and spectrophotometric study (573 K) of KCl-FeC1, melts.'13 Certain identification of the complexes in the LiC1-ThCl, system was not possible in a study (963-1203 K) of the vapour phase in equilibrium with the melt.'', The reaction of MS, (M =Ti or Nb) with H2S in alkali-metal halide melts in a flow reactor system (1073-1273 K) yielded layered ternary sulphides, A,,sMS2 (A = Li,Na,K,Rb, or Cs; M =Ti or Nb)."' ZrP,07 and MZr,(PO,), (M = Na or K) are formed on reaction of Zr(PO,), with MCl (M=Na or K) rnelts.'l6 The influence of pretreatment conditions and of cover gas (air, Ar, or Cl,) is consi- dered; whereas ZrP,O, is converted into MZr,(PO,), in the presence of air, such a change is not observed in the presence of Ar or C1,.'16 lo5 K. C. Hong and 0. J. Kleppa, J. Chem. Thermodynamics, 1976, 8, 31. '06 G. Yu. Sandler, I. L. Reznikov, and E. I. Yaskelyainen, Russ. J. Phys. Chem., 1975, 49, 462. lo' F. Dienstbath and R. Blachnik, Z. anorg. Chern., 1975, 417, 100. log J. L. Holm and 0. J. Kleppa, J. Chem. Phys., 1968, 49, 2425. 'lo R. A. Gilbert, J. Phys. Chem., 1963, 67, 1143. '11 A. C. Macleod and J. Cleland, J. Chem. Thermodynamics, 1975, 7, 103. '12 B. P. Burylev and V. L. Mironov, Russ. J. Phys. Chem., 1975, 49, 937. H. A. Andreasen and N. J. Bjerrum, Inorg. Chem., 1975, 14, 1807. '14 M. V. Smirnov, V. N. Khudolozhkin, and V. Ya. Kudyakov, Russ. J. Phys. Chem., 1975, 49, 822. '15 R. Schollhorn and A. Lerf, J. Less-Common Metals, 1975, 42, 89. '16 A. I. Kryukova, N. V. Vorob'eva, I. A. Korshunov, G. N. Kazantsev, and 0. V. Skiba, Russ. J. Inorg. 0. J. Kleppa and M. Wakihara, J. Inorg. Nuclear Chem., 1976, 38, 715. 1-13 Chem., 1976, 21, 228. Elements of Group I 17 The stoicheiometry and mechanism of the cathodic reduction of HCl dissolved in LiCI-KCl eutectic mixture have been elucidated.' l7 Complete dissociation into H' and C1- ions occurs, followed by a two-step cathodic evolution of H, [equation (1 l)]; the charge-transfer step is reversible and faster than the combination H++e- H; H+H + H, (11) reaction. Interaction of Sn2+ions with F-, Br-, I-, and CN- ions has been studied in an equimolar NaC1-KC1 melt and the data have been compared with those of the similar Pb2' system.'" Sn2' is capable of forming complexes with halide ions by a single co-ordination step; under the same conditions, Pb2' does not show the ability to form complexes with Br-, but is capable of co-ordinating up to three CN- ions. The stability constants of the complexes formed [MF', SnBr', MI', MCN', Pb(CN),, and Pb(CN), (M=Sn or Pb)] have been determined. Four solvated Se species of low oxidation state (possibly Sei+, Sei', Set;, Se:;) have been detected in a spectrophotometric study"' of the reduction (by Se) of dilute solutions of SeCl, in NaCI-AlCI, eutectic mixture. Several studies of the behaviour of the lanthanides and actinides in molten halides have been undertaken recently. '20-'25 E.m.f. measurements have estab- lished that Nd3+ions are in equilibrium with the metal in LiCI-KC1 eutectic melt containing 2 wt O/ O NdC1, (700-912 K),12' and that Th4' ions exist in solutions of ThCI, in LiC1-KCI eutectic melts (573-1373 K).12' This latter observation con- tradicts an earlier report of thorium of low oxidation state [namely (II)] in these melts; the erroneous data are explained on the basis of contamination by Tho, and on misinterpretation of the e.m.f .-composition plots.121 Reactions of Th and ThCl, with UO, and (Th,U)02 in fused LiC1-KCl and NaC1-MgCl, eutectic melts have also been studied (773-973 K),12, the equilibrium (12) being considered in ThCl, +Tho, 2ThOC1, (12) some detail. By sparging gaseous mixtures (containing H20, HCl, Cl,, N,) of known composition through the melts, a study of the redox behaviour of Np [equations (13) and (14)] in solution in the fused LiC1-KCl eutectic mixture has NpOZ+ + C1- -+NpOl + iC1, (13) NpOl + 4HC1 + Np4+ + 2H,O + iC1, + 3C1- (14) been effe~ted.',~ The investigation was rendered quantitative by following the variation in concentration of the Np species, using visible and near-i.r. absorption spectroscopy. Thermodynamic properties of dilute solutions of actinide chlorides in LiCl-KC1 (UCl,, UCl,, NpCl,, NpCl,, and PuC1,) and LiC1-NaC1 (UCl, and UCl,) eutectics have also been investigated (673-823 K).124 The heterogeneous '18 Yu K. Delimarskii, L. I. Zarubitskaya, and V. F. Grischenko, Russ. J. Inorg. Chem., 1976,21,221. '" R. Fehrmann, N. J. Bjernun, and H. A. Andreasen, Inorg. Chem., 1975,14, 2259. 120 A. P. Bayanov, E. N. Ganchenko, and Yu. A. Afanas'ev, Rum. J. Phys. Chem., 1975, 49, 1442. 12' P. Chiotti and C. H. Dock, J. Less-Common Metals, 1975, 41, 225. lZ2 P. Chiotti, M. C. Jha, and M. J. Tschetter, J. Less-Common Metals, 1975, 42, 141. 123 R. Lysy and G. Duyckaerts, Inorg. Nuclear Chem. Letters, 1976, 12, 205. 124 L. Martinot, J. Inorg. Nuclear Chem., 1975, 37, 2525. N. Q. Minh and B. J. Welch, Austral. J. Chem., 1975, 28, 2579. 18 Inorganic Chemistry of the Main- Group Elements catalytic reduction of Uv to UIV by H, [equation (15)] has been studied at 328 K, in molten LiF-BeF,-ThF, (72-16-12 mol. %), which is the composition of the fuel carrier salt for the molten-salt breeder ~eact0r.l ~~ The hydrogen reduction is rate-determining; the application of Pt catalysts to achieve a 10- to 100-fold increase in reaction rate has been re~0rted.l ~~ Nitrates. Thermodynamic parameters (A H = 114 kJ mol-'; A P = 62 J rno1-l K-') for reaction (16) in NaN0,-KNO, eutectic melt have been determined (500- 700 K),126 Corresponding data ( A H = 95 kT mol-'; AS*= 84 J mol-' K-l) for reac- tion (17) have also been calculated. Physicochemical analyses have been carried out on NaN03-KN0,,127 Ca(N0,),-Sr(N0,),,128 Sr(N03)2-Ba(N03)2128 binary systems (generally as part of a quaternary reciprocal system), and LiN03- R~NO,-CSNO,~~' and LiN03-KN03-Sr(N03)2130 ternary systems. NO; + NO; +$0, NO; +i0;- + NO; +0; (16) (17) The reactions of TiS,, VS, Cr,S,, and MS (M = Mn, Fe, Co, Ni, Cu, or Zn) with molten KNO, have been studied.I3' Ti, Ni, Cu, and Zn ions exhibited acid-base reactions and were precipitated as metal oxides; V, Cr, Mn, Fe, and Co ions showed redox, as well as acid-base, reactions, and were converted into VO,, CrOz-, MnO,, Fe203, and Cr,O,, respectively. In all cases, S2- was oxidized to SO:- and the nitrate melt was reduced to nitrite and nitrogen 0~i des.l ~' The electrochemical behaviour of H,O in molten LiN0,-KNO, eutectic has been e1~ci dated.l ~~ Contrary to previous reports, electroreduction of H,O is coupled with nitrite reduction, probably involving an autocatalytic mechanism and an adsorbed intermediate. The kinetics of reaction (18) have been ascertained by allowing Na4P,0, to react with nitrate melts in the temperature range 610-625 K.13, The reaction only occurs in the presence of Li' ions; this observation is rationalized by a reaction mechanism in which P204- experiences a change in its average co- ordination with increasing Li' concentration, resulting in the P-0-P bridge being made more susceptible to rupture by NO, at higher Li' 1e~el s.l ~~ P,O;- + 2N0; -+2PO:- +2N0, (g) + i02 (8) (18) The reactions of a number of titanium-(m) and-(Iv) compounds (K2TiFs, TiCl,, TiO,, TiC14)134 and of iron-(II), -(I~I), and -(w) compounds [K2Fe04, FeCl,, A. D. Kelmer and M. R. Bennett, Inorg. Nuclear Chem. Letters, 1976, 12, 333. lZ6 F. Paniccia and P. G. Zambonin, J. C. S. Faraday I, 1976, 72, 1512. lZ7 H. Aghai-Khafri, J. P. Bros, and M. Game-Escard, J. Chem. Thermodynamics, 1976, 8, 331. P. I. Protsenko and L. M. Kuvakina, Russ. J. Inorg. Chem., 1975, 20, 924. Yu. G. Litvinov, I. I. Il'yasov, and V. I. Sawa, Russ. J. Inorg. Chem.. 1975, 20, 1418. A. I. Kryukova and I. A. Korshunov, Rwss.J. Znorg. Chem., 1975,20,809. 128 129 13' B. J. Meehan and S. A. Tariq, Austral. J. Chern., 1975, 28, 2073. 13' D. G. Lovering, R. M. Oblath, and A. K. Turner, J. C. S. Ge m. Comm., 1976, 673. 133 J. L. Copeland, A. S. Metcalf, and B. R. Hubble, J. Phys. Chem., 1976, 80, 236. 134 D. H. Kerridge and J. C. Rey, J. Inorg. Nuclear Chem., 1975, 37, 2257. Elements of Group I 19 FeO(NO,), FeS04,2H20, FeC1,,4H20, FeC0,]135 have been studied in molten LiNO,-KNO, eutectic. In the Ti study, which was also effected in basic nitrate melt solutions containing Na202, Na20, or NaOH, TiO, (as anatase) and titanates of varying basicity were produced, depending on base concentrations and temper- ature; when C1- was present, (NO),[Ticl,] sublimed from the melts.134 For the Fe systems, Fe203 was invariably the final product, although there was evidence for the intermediate formation of higher oxides from K2Fe04 and of ferrate(II1) from FeO(N0,); C1- ions stabilized Fe3' cations in the melt solution, but not Fe2' cations . The kinetics of oxidation of formate in molten equimolar NaNO,-KNO, have been determined (538-585 Although the reactions could not be rep- resented by a simple stoicheiometry, the kinetic analysis indicates that nitrite has a role as an oxidant and as a catalyst, as well as being a product of the oxidation. A series of reactions, which include acid-base-dependent and -independent processes, possibly involving as intermediates NO; and NO' cations and nitrogen oxides, respectively, have been proposed to account for the observed kinetic data. 136 6 Compounds of the Alkali Metals containing Organic Molecules or To simplify the text in this Section, radical anion salts and crown compounds and cryptates are considered collectively in special subdivisions. The majority of the data, however, are discussed in subdivisions devoted to derivatives of the indi- vidual alkali metals. For those data pertinent to several alkali metals, they are described once only, in the subdivision of the lightest metal considered. Radical-anion Salts.-Radical-anion salts of the alkali metals have been prepared in neat solvents under high-vacuum conditions, by bringing a solution of a crown compound in benzene, toluene, or mesitylene into contact with an alkali-metal Two complexes containing a dilithiated stilbene fragment have been prepared and isolated from the reactions of 1,2-diphenylethane with N-chelated butyl- lithium The molecular and crystal structures of these compounds, stilbene bis(1ithium tetramethylethylenediamine) (Figure 4a) and stilbene bis(1ithium pentamethyldiethylenetriamine) (Figure 4b), have been determined by X-ray diffraction techniques. Each structure contains two amine-solvated Li atoms located above and below the olefinic bond of a stilbene molecule. The stilbene molecule is planar in both structures, and is in a trans configuration about the C(7)-C(7') bond, which is ca. 0.01 nm longer than that in tr~ns-stilbene.'~~ The optical and 13C n.m.r. spectra of THF solutions of the related dilithium and disodium salts of tetraphenylethylene dianion, as well as the spectra of their mixtures, have been examined.139 The data can be rationalized in terms of the Complex Ions reaction begins quickly, and is complete after a few hours at 253K. 13' D. H. Kerridge and A. Y. Khudhan, J. Inorg. Nudear Chem., 1975, 37, 1893. 13' D. H. Kerridge and J. D. Bourke, J. Inorg. Nuclear Chrn., 1976, 38, 1307. 13' G. V. Nelson and A. von Zelewsky, J. Amer. Chem. SOC., 1975, 97, 6279. 13' M. Walczak and G. Stucky, J. Amer. Chem. SOC., 1976, 98, 5531. 139 G. Levin, B. Lunderen, M. Mohammad, and M. Szwarc, J. Amer. Chem. Soc., 1976, 98, 1461. 20 Inorganic Chemistry of the Main-Group Elements AC2' ACl c4 C4/ C3f c2' 1ac1' 1ac2' 1ac3' IAC1 LAC3 a' cs' c2 c3 c4' C4 a' c2' as c5 c12' (b) Figure 4 The molecular structures of (a) stilbene bis(1ithium tetramethylethylenediamine) and (Reproduced by permission from J. Amer. Chem. SOC., 1976, 98, 5531) (b) stilbene bisflithium pentamethyldiethylenetriarnine) Elements of Group I A 21 Y 0 Oxygen 0 Carbon Figure 5 Environment of the Rb+ ion in biphenylrubidium bis(tetrag1yme) (Reproduced by permission from J. Arner. Chem. SOC., 1976, 98, 680) tentative salt structure Li+,Ph2CxPh2,Li+, in which the two CPh, groups are lying in two mutually perpendicular planes. One Li' ion is located close to the negative carbon framework and the other is fully solvated by THF molecules some distance away. The molecular and magnetic structures of biphenylrubidium bis(tetraglyme) have been e1~cidated.l~' Single-crystal X-ray diffraction data show each Rb' ion to be spherically surrounded by 10 oxygen atoms of the solvent molecules (Figure 5) , leading to a solvent-separated ion-pair structure. E.s.r. and n.m.r. data are consistent with the observed dimeric structure of the biphenyl anions.14o The disproportionation [reaction (19)] of lithium salts of radical anions of naphthalene, anthracene, tetracene, perylene, and pyrene in Et2Ol4I and of sodium tetracenide in C6&142 has been investigated. The magnitudes of the disproportionation constants of the lithium salts are astonishingly great; neverthe- less, an interesting correlation between these values and the cation-anion Coulomb energy has been 0b~erved.l ~~ Crown and Cryptate Complexes.-Interest in crown, cryptate, and related com- plexes of alkali-metal (and alkaline-earth-metal) ions has been maintained during the period of this Report. A new class of ether-ester ligands (4) and (5) has been deve10ped.I~~ Whereas (4) forms complexes with Mg", Ca2', Sr2+, and Ba2+, (5) forms complexes with Ca", Sr*', and Ba2' only. The complex between (4) and Mg2' is the first reported Mg2+crown compound; although the Mg2+is probably bound within the cavity, it is possible that it may be bound to the externally directed 1,3-dicarboxy-gro~p.l~~ 2A'- A+A2- (19) 140 J. J. Mooij, A. A. K. Klaasen, E. de Boer, H. M. L. Degens, Th. E. M. van den Hark, and J. H. 14' G. Levin, B. E. Holloway, and M. Szwarc, J. Amer. Chem. SOC., 1976, 98, 5706. 14' J. Pola, G. Levin, and M. Szwarc, J. Phys. Chem., 1976, 80, 1690. 143 J. S. Bradshaw, L. D. Hansen, S. F. Nielsen, M. F. Thompson, R. A. Reeder, R. M. Izatt, and J. J. Noordik, J. Arner. Chem. Soc., 1976, 98, 680. Christensen, 1. C S. Ge m. Comm., 1975, 874. 22 Inorganic Chemistry of the Main- Group Elements ( 6) (7) R' =R2=H (8) R1 =R2 =But (9) R1 = H; R2 = C,,H,, A number of crystalline complexes of DB12C4 (6), of DB18C6 (7) and its derivatives (8) and (9), and of DB24C8 (10) with some M' and M2" perchlorates and picrates have been synthesized. 144 Identification and characterization was effected by elemental analysis, i.r., u.v., 'H n.m.r. spectroscopy, conductivity, and X-ray diffraction analysis. With complexes of (8) and (9), it was not possible to isolate all complexes in the crystalline form; indeed, the steric hindrance afforded by the alkyl substituents affects the stability of the complexes and hinders the possibility of is01ation.l~~ The crystal and molecular structures of the complex formed between DB24C8 (10) and two molecules of sodium o-ni tr~phenol ate~~~ and of the solvated (MeOH 144 Lj. Tusek, M. Meider-Gorican, and P. R. Danesi, Z. Nuturforsch., 1976, 31b, 330. 145 D. L. Hughes, J. C. S. Dalton, 1975, 2374. Elements of Group I 23 Figure 6 Projections of (a) the crown ligand (DB24C8) and Na+ ions on the mean plane of the 8 ether oxygen atoms, and (b) the o-nitrophenolate ion on the mean plane of the 6 ring carbon atoms, in the crystal formed between DB24C8 and two molecules of sodium o-nitrophenolate. The atomic numbering scheme, bond lengths, and Na - * 0 distancesIA are shown (Reproduced from J. C. S. Dalton, 1975, 2374) or H20) complex formed between B15C5 (12) and Ca(NCS),146 have been determined. In the Na' complex, the polyether ring folds around the pair of Na' ions (Figure 6a). Each cation interacts with three oxygen atoms of the ligand; each of the fourth pair of oxygen atoms is 0.2965nm from a cation; not directed towards the cation, and not involved in co-ordination. An o-nitrophenolate anion on each side of the crown ring completes the six-fold co-ordination of the cations; each anion chelates one cation, and the phenolate oxygen (carrying most of the anionic charge) bridges the pair of cations (Figure 6b).145 The molecular structures of the Ca2' complexes show a new irregular conformation of the crown ether (consistent with i.r. spectra) and eight-fold co-ordination of Ca2', comprising five ether oxygen atoms, two isothiocyanate nitrogen atoms, and one oxygen atom from the solvent (Figure 7).146 146 J. D. Owen and J. N. Wingfield, J. C. S. Chem. Comm., 1976, 318. 24 Inorganic Chemistry of the Main- Group Elements COPT O 7 (11) (12) R= H (13) R=alkyl (14) R=H (15) R=alkyl Figure 7 Co-ordination polyhedra of the Ca2+ ion in BISCS-Ca(NCS),-MeOH (Reproduced from J. C. S. Chern. Cornm., 1976, 318) Two s t u d i e ~ l ~ ' , ~ ~ ~ of the solution structures of these complexes have been undertaken, using n.m.r. spectroscopic techniques. The interactions of Na+, K', Cs', and Ba2' with DB18C6 (7), B18C6 (14), and DB30C10 ( l l ) , in H20, H20-acetone mixtures, and CHCl,, have been studied by 'H- and 13C-n.m.r. spectroscopy as a function of concentration and of the anion (I-, SCN-, and C10T).147 Complexes of (7) and (14) have the same structures in solution 14' D. Live and S. I. Chan, J. Amer. Chem. Soc., 1976, 98, 3769. E. Mei, J. L. Dye, and A. I. Popov, J. Amer. Chem. k. , 1976, 98, 1619. 148 Elements of Group I 25 as complexes of (7) in the crystalline Although K', Cs', and BaZ+ derivatives of (11) in solution were found to have the same configuration as that reported for the crystalline K+ complex,'5o the Na+complex has an alternative struc- ture.14' Evidence has been presented for complete removal of the solvation sphere of the cation on complexation to (ll), but this is not the situation for (7) and (14). The existence of a previously postulated 'sandwiched' complex with a Cs' ion between two molecules of (7) in solution has also been demonstrated. 133Cs n.m.r. studies of Cs' complexes of (16) and (17), in propylene carbonate (PC), pyridine (PY), acetone, DMF, DMSO, and acetonitrile (AN), have shown that the solvent plays an important role in the complexation process.148 In PC, PY, and acetone, the data for the crown complex indicate a two-step reaction with increasing ligand concentration: (i) the formation of a stable 1 : 1 complex, and (ii) the addition of a second molecule to form a 2 : 1 'sandwich' complex (see above147). In DMSO and AN, 'sandwich' complexes are not The cryptate complex is less stable than the crown complex. Furthermore, the Cs' ion is either not fully enclosed by the ligand or the solvent can interact with it through the cryptate openings.148 Several papers defining the thermodynamic properties (stabilities) of crown and cryptate complexes of M' and M2' ions have been published re~entl y;l ~l -'~~ the origins of the stability sequences are generally discussed in terms of cation size and ligand structural features (topology, binding sites, etc.). Stability constants, at infinite dilution, for complex formation of DB18C6 (7) with, inter alia, Nat, K+, Rb', Cs', Sr", and Ba2' have been determined spectrophotometrically in aque- ous The monodissociated ion pairs (SrCl)' and (BaCl)' complex more strongly with (7) than the free ions Sr2' and Ba2'. The behaviour of (7) with M2' ions is much more sensitive to their ionic size than in the case of M' ions.151 Similar data for complex formation of (7) with M' ions have been determined in DMSO, DMF, and PC.152 The results show that the selectivity of (7) towards M' is dependent on ionic diameter, cavity size, and the donor number of the solvent. The effect of substituents on the stability of Na' and K' complexes of B15C5 (13) 149 D. Bright and M. R. Truter, J. Chem. Soc. (B), 1970, 1544. M. A. Bush and M. R. Truter, J. C. S. Perkin U, 1972, 345. lS1 E. Shchori, N. Nae, and J. Jagur-Grodzinski, J. C. S. Dalron, 1975, 2381. lS2 N. Matsuura, K. Umemoto, Y. Takeda, and A. Sasaki, BuII. Chem. SOC. Japan, 1976, 49, 1246. lS3 R. Ungaro, B. EIHaj, and J. Smid, J. Amer. Chem. Soc., 1976, 98, 5198. lS4 J. M. Lehn and J. P. Sauvage, J. Amer. Chem. Soc., 1975, 97, 6700. 26 Inorganic Chemistry of the Main- Group Elements and B18C6 (15), in acetone, has been e~tab1ished.l~~ Although the effect is pronounced for Na' complexes of (13), it is much smaller for Na' complexes of (15), being almost non-existent for electron-withdrawing substituents. Substituent effects were somewhat larger for K' complexes of (15). Although formation constants could not be determined for K' complexes of (13), substituent effects on complexation were noticeable. 153 Concurrent conductivity studies have shown that 1 : 1 and 2 : 1 crown : cation complexes can exist simultaneously in mixtures of K' with (13).153 Conductivity studies on the association of complexes of (7) with Na' and K' ions and SCN- ions, in nitrobenzene-toluene mixtures, have also been undertaken. 155 The stability constants of complexes formed by cryptates (18)-(23) with M' and M2' ions have been The cryptate complexes of maximum stability display much higher stability than any previously known complexes. The selectivity of the complexes is remarkable. The optimum fit of M' into the ligand cavity agrees well with the selectivity of the ligands (18), (19), and (20) for Li', Na', and K', respectively. Whereas these smaller ligands display peak selectivity, the larger ones display plateau selectivity, with only small differences in stability for K+, Rb', and Cs'. Unusual selectivities are observed for complexes of M2' ions; for example, the high Ca2'/Mg2', Ca2'/Sr2', and Ba2'/Ca2' ratios for ligands (18), (19), and (20), respectively. Furthermore, M2'/M+selectivities are of consid- erable interest, particularly the unique selectivity of ligand (18) for Li' over Mg2' and Ca". A marked increase in cryptate complex stability and selectivity is observed in changing solvent from H20 to MeOH.154 The kinetics of complexing of Ca2' by ligands (18)-(20) have also been e~tablished."~ u b e (18) 1 0 0 (19) 1 1 0 (20) 1 1 1 (21) 2 1 1 (22) 2 2 1 (23) 2 2 2 The crystal structures of Na', K', and Rb' tetranactin complexes have been The data have been considered in detail in a previous as a result of abstraction from a preliminary communication.159 published in lS5 P. R. Danesi, R. Chiarizia, C. Fabiani, and C. Domenichini, J. Inorg. Nuclear Chern., 1976,38,1226. lS6 V. M. Loyola, R. G. Wilkins, and R. Pizer, J. Arner. Chern. SOC., 1975, 97, 7382. 15' T. Sakamaki, Y. Iitaka, and Y. Nawata, Acta Cr y s t . , 1976, B32, 768. R. J. Pulham, in 'Inorganic Chemistry of the Main-Group Elements' (Specialist Periodical Reports), ed. C. C. Addison, The Chemical Society, London, 1974, Vol. 2, p. 28. lS9 Y. Iitaka, T. Sakamaki, and Y. Nawata, Chem. Letters, 1972, 1225. Elements of Group I 27 Figme 8 Co-ordination of the Li+ions in lithium tetrakis(dimethylphenylsilyl)rnercurate(xr): only the carbon atoms fotming the cages around the Li' ions are included; the C(2) and C(2') carbons are methyl carbons, while all other carbons are phenyl carbons (Reproduced by permission from J. Amer. Chem. SOC., 1975, 97, 6261) Lithium Derivatives.-The crystal and molecular structures of lithium tetrakis(di- methylphenylsilyl)mercurate(Ir) have been determined.la The Li' ion (Figure 8) is novelly encompassed in a cage composed of five carbon, three silicon, and one mercury atom. The Li + - C distances (0.24-4.26 nm) are slightly longer than those in alkyl-lithium derivatives, but similar to those in lithium-hydrocarbon ion pairs. The Li - * Si distances (0.29-0.30 nm) are longer than those observed in silyl-lithium derivatives; the Li * Hg distance is 0.258 nm. In a single-crystal neutron and X-ray diifraction investigation of Li - - - H - - C interactions in LiB(CH,),, the Li atoms are shown to be bridged by the B(CH,), groups, through linear B - - - CH, - Li and multi-centre fragments (Figure 9).16' The structural features in the linear B - 9 - CH, - - Li moiety are similar to those found in the intermolecular interaction between tetrameric units in CH,Li, with a trihydrogen-bridged group. The other methyl bridging arrangement is similar to that in [(CH,),Al],, with a dihydrogen-bridged linkage. Mass spectrometric studies show that LiB(CH,), is also associated in the gas phase.16' Alkali-metal dimethylformamidyls, MCONMe, (M = Li-Cs), have been pre- pared by direct reaction between the metal and DMF;I6' characterization of the products was based on elemental analysis, i.r. spectroscopy, and t.g.a. data. Direct "" M. J. Albright, T. F. Schaaf, W. M. Butler, A. K. Hovland, M. D. Glick, and J. P. Oliver, J. Amer. "' W. E. Rhine, G. Stucky, and S. W. Peterson, J. Amer. Ge m. Soc., 1975, 97, 6401. lL2 R. C. Paul, B. N. Anand, and R. Kapoor, Indian J. Chem., 1975,13, 1338. Chem. Soc., 1975,97,6261. 28 Inorganic Chemistry of the Main- Group Elements Figure 9 Partial molecular stmcture of LiB(CH,),, showing the bridging and linear methyl (Reproduced by permission from J. Arner. Chem. SOC., 1975, 97, 6401) geometry reaction of Li vapour with alkenes (e. g. isobutene, butadiene) yields polylithiated alkanes and alkenes, v i a both Li substitution for H and Li addition to the ethylenic The products were reactive, red-black solids, which, although metallic in appearance, were very brittle.'63 Vibrational spectra of a number of moieties (complex amides, crown complexes, oxide glasses, oxyanions) have been assigned, assuming a basic four-co-ordinate Li - - - 0 polyhedron [v(asym) = ca. 400 cm-1].164 Similar but more limited data were obtained for compounds of Na+, K ' , and Mg2+. Five-fold co-ordinate Li, in the form of a distorted trigonal bipyramid with Li - - * 0 distances varying from 0.2031 to 0.2122 nm, has been observed in the molecular structure of lithium hydrogen oxydiacetate.165 The bipyramids form pairs by sharing an edge, with a shortest Li * Li distance of 0.3156 nm. The interaction of Li', Na+, and Kf with cis- and trans-l-benzyl-2,3- dibenzoylaziridine in MeCN has been studied by means of 'H n.m.r. and i.r. spectroscopy.166 For all cations, association with the cis-isomer is preferred, presumably via chelation at the carbonyl oxygens; the order of association was Li' > Na' > K'. At a LiBr : cis-isomer ratio above 0.4, a white crystalline product, which analysed to a 2 : 1 adduct of LiBr, could be isolated.'66 Finally, e.s.r. spectra of the ion pairs formed by the 4-nitropyridine anion radical with Li', Na', and K ' in dimethoxyethane and THF have been determined as a function of tempera- ture.16' 163 164 165 166 167 J. A. Morrison, C. Chung, and R. A. Lagow, J. Amer. Chem. SOC., 1975, 97, 5015. C. N. R. Rao, H. S. Randhawa, N. V. R. Reddy, and D. Chakravorty, Specrrochirn. Actu, 1975, 314 1283. H. Herbertsson, Actu Cryst., 1976, B32, 2381. A. B. Norman, G. R. Smith, and H. P. Hopkins, J. Phys. Chem., 1976, 80, 25. P. Cremaschi, A. Gamba, G. Morosi, C. Oliva, and M. Simonetta, J. C. S. Faraduy 11, 1975, 71, 1829. Elements of Group I 29 Ssdium Derivatives.-The crystal structures of a number of Na salts of carboxylic acids, uiz. (HC0,)Na,168 (MeC02)Na,3H20,'69 C6H,(C02H)C02Na,~H,0,170~171 have been published recently. The independent of the acid phthalate hemihydrate give almost identical data; the Na' ion is six-co-ordinate, surrounded by 4 oxygen atoms from the ionized carboxy-group, one oxygen atom from the unionized carboxy-group, and one from the H,O molecule. The Na - - - 0 dis- tances range from 0.230 to 0.256nm (average 0.244nm).170 Similar six-fold pseudo-octahedral co-ordination occurs in the formate168 and acetate169 deriva- tives, with Na * 0 distances in the ranges 0.240-0.252 (average 0,245) and 0.235-0.256 nm (average 0.244 nm), respectively. In the acetate structure,169 adjacent octahedra share an edge to form a continuous chain along the z-axis, the Na - * Na separation ranging from 0.339 to 0.356 nm. The crystal structure of the complex of NaCl with phenacylkojate (pak), NaCl(pak),, has been deter~nined.'~~ The monoclinic structure of the complex closely resembles that of the corresponding KI complex, the alkali metal being eight-co-ordinate in each-a higher co-ordination number than is usual for Na'. The Na - - - 0 distances range from 0.2558 to 0.2674 nm (average 0.262 nm), in agreement with those for other complexes containing eight-co-ordinate Na.17' The crystal structure of the similar 23- 0 -methylene-~-mannitol,NaCl complex has also been in~estigated.'~~ The Na atom is co-ordinated (with Na. - - 0 distances 0.2314 to 0.2417 nm) to 6 oxygen atoms comprising O(3) and O(4) from one organic molecule, 0(1) and O(2) from a second molecule, and O(5) and O(6) from a third. This highly symmetrical and efficient six-fold co-ordination of Na' ions without incorporation of H,O molecules is thought to account for the surprising stability of the crystalline complex.173 The interaction of sugars with Na' ion in pyridine solution has been the subject of a 23Na n.m.r. inve~tigation."~ One sorbose molecule is inserted in the Na' solvation shell, with attendant loss of a pyridine molecule; the Na' co-ordination sphere in the resultant complex is visualized as comprising 3 pyridine nitrogens and 2 (or 3) sugar oxygens. Hydrogen-bonding in the carboxylic ionophorous antibiotic Lasalocid A (X- 537A), its Na complex, and their deuteriated analogues has been studied, using Raman spectroscopy.175 The data indicate that the observed conformation of the complex is stabilized primarily by cation-oxygen interactions, rather than hyd- rogen bonds; a conclusion which is inconsistent with conventional interpretation of X-ray diffraction data of the corresponding Ag+and Ba2+complexes.175 Two independent n.m.r. studies of the effect of alkali-metal cations (Na') on the conformational equilibrium of the acetylacetonate ion have been effected. 176~177 have demonstrated that the two configurations '" P. L. Markila, S. J. Rettig, and J. Trotter, Actu Crysf., 1975, B31, 2927. T. S. Cameron, Kh. M. Mannan, and M. 0. Rahman, Acta Crysf., 1976, B32, 87. R. A. Smith, Actu Cryst., 1975, B3l, 2345. S. E. V. Phillips and J . Trotter, Cunad. J. Chem., 1976, 54, 2723. 17' R. Fiedler and H. Follner, Nuturwiss., 1975, 62, 573. 173 R. A. Wood, V. J. J ames, and J. A. Mills, Crysf. Struct. Cornm., 1976, 5, 207. 174 C. Detellier, J. Grandjean, and P. Laszlo, J. Amer. Chem. Soc., 1976, 98, 3375. 17' G. D. J. Phillips and H. E. Stanley, J. Amer. Chem. Soc., 1976,98, 3892. 1 7 ' E. A. Noe and M. Raban, J. Amer. Chem. Soc., 1976, 98, 641. 177 E. A. Noe and M. Raban, J. C. S. Chem. Comm., 1976, 165. 30 Inorganic Chemistry of the Main-Group Elements present in pyridine solution containing crown compounds are E, Z- (25) and 2,Z- (26), rather than E,E- (24) and 2,Z- (26) as previously re~0rted.l ~~ The equilib- rium between the E, Z- (25) and Z, Z- (26) configurations in CD,OD is shifted towards the chelated [Z, Z- (26)] form by an increase in the concentration of Na' ions.177 Data concerning the association of Na+, K', and-Cs' with some polyethylene glycol ethers (e.g. MeO[(CH,),O],Me, 4 s n S 7 ) in MeOH at 298K have also been reported.*" Me Me Me 0 0 Me Me H H H EE (24) EZ (25) The adduct Na( h5-C5H5)(Me2NCH2CH2NMe2), prepared from Na(C,H,) and Me,NCH,CH,NMe, in THF, has been shown, by single-crystal studies, to adopt a puckered-chain structure (Figure 10) in which Na(Me,NCH,CH,NMe,) units are linked by bridging h5-C5H, rings."' Sodium atoms occupy two sites on 2-fold axes, which are alternately in the plane and perpendicular to the plane of the Figure. They are surrounded by a distorted tetrahedral arrangement of two Me,N groups (Na . N = 0.305,0.308 nm) and two hS-C,H, rings [Na - - C (average) = 0.292 nm]. The structure is consistent with an ionic Na(TMED)+.C,Hi model, although the Na - - - C distances are short enough to allow a degree of cova- lency.180 Vibrational spectra of Na'[ ( hS-C5H,)Fe(C0)2]-, recorded in ethereal solvents in the presence of DB18C6 (7), indicate the presence of three distinct ion pairs:181 (i) one with a direct Na * Fe interaction, (ii) another with a more normal Na - - 0 (carbonyl) interaction, and (iii) a solvent-separated ion pair. The related Mo compound, N~+[(~'-C,H,)MO(CO)~P(OP~)~]-, exhibits only two ion pairs comparable to (ii) and (iii) above.lS1 Figure 10 MoZecuZar structure of the adduct (h5-C5H5)Na(Me2NCH2CH2NMe2), showing (Reproduced from J. C. S. Chem. Comm., 1976, 164) the co-ordination of the Na atoms 1 7 ' E. A. Noe and M. Raban, J. Amer. Chem. Soc., 1974, 96,6184. 179 G. Chaput, G. Jeminet, and J. Juillard, Canad. J. Chem., 1975, 53, 2240. ''* K. H. Pannell and D. Jackson, J. Amer. Chem. Soc., 197698,4443. T. Aoyagi, H. M. M. Shearer, K. Wade, and G. Whitehead, J. C, S. Chem. Comm., 1976, 164. Elements of Group I 31 The crystal structure of the high-temperature modification of Na'TCNQ- has been determined at 353 K.lS2 The Na' ion is surrounded almost octahedrally by the six negatively charged N atoms of different TCNQ- ions, with Na - - N distances 0.2421-0.2560 nm; the co-ordination geometry is very similar to that of the low-temperature phase. Potassium Derivatives.-Six-fold, 183~184 ~even- f ol d,'~~* ~~~ and l O- f ~l d'~~ co- ordination of K' ions has been demonstrated in single-crystal X-ray diffraction studies of a number of complex potassium salts. Whereas the six-fold co- ordination in potassium hydrogen mesac~nate~~~ is reasonably regular (K - w 0 distances vary from 0.270 to 0.288 nm), that in potassium 17&hydroxy-3-oxo- 4,6-pregnadiene-21-carboxylate (potassium canren~ate) ~~~ is highly distorted (five K - - * 0 distances range from 0.2668 to 0.2858 nm, with a sixth at 0.3032 nm), the supposedly octahedral (90") angles ranging from 45.3 to 118.8". Seven-co- ordinate K" is found in potassium acetylacetonate hemihydratels5 and the potas- sium salt of N-(purin-6-ylcarbamoyl)glycine monohydrate.'86 The K 6 - 0 dis- tances for the acetylacetonate (6 from 4 anions and one from H,O) range from 0.265 to 0.305 nm.ls5 This irregular seven-fold co-ordination can be described as a sandwich of two K' ions between two distorted pentagons, as shown in Figure 11. The K' co-ordination sphere in the glycine derivative,'86 which cannot be described in terms of simple geometry, is composed of two H20 oxygens, two keto oxygens from independent ureido-groups, two oxygens of different carboxy- groups, and one nitrogen atom. K - * 0 distances vary from 0.268 to 0.291 nm, with a K - - - N distance of 0.290 nm. The 1 : 2 potassium 00'-catecholdiacetate Figure 11 Environment of the K+ ions in potassium acetylacetonate hemihydrate; this unusual seven-fold co-ordination can be described as a sandwich of two K+ ions between two distorted pentagons (Reproduced by permission from Bull. Chem. SOC. Japan, 1975, 48, 2516) la* M. Konno and Y. Saito, Acfa Cryst., 1975, B31, 2007. ' ~4 D. C. Rohrer, C. M. Weeks, and W. L. Duax, Cr y s t . Strucf. Comm., 1976, 5, 237. la5 S. Shibata, S. Onuma, Y. Matsui, and S. Motegi, Bull. Chem. Soc. Japan, 1975, 48, 2516. R. Parthasarathy, J. M. Ohrt, and G. B. Chheda, Acru Cr yst ., 1976, B32, 2648. la' E. A. Green, W. L. Duax, G. M. Smith, and F. Wudl, J. Amer. Chem. Soc., 1975,97, 6689. M. P. Gupta and S. R. P. Yadav, Z. Krist., 1975,141, 151. 32 Inorganic Chemistry of the Main- Group Elements (b) Figure 12 Potassium 00'-CatechoZdiacetate (1 : 2) complex, illustrating (a) the sandwiching of the K+ ion between symmetry-related (C,) pentagons of oxygen atoms, and (b) the geometry of the pentagon of oxygen atoms co-ordinated to the K+ ion (Reproduced by permission from J. Amer. Chem. SOC., 1975, 97, 6689) complex187 contains a 10-co-ordinate K ' ion (Figure 12a). The co-ordinating atoms are the ether and carboxyl oxygens from one crystallographic asymmetric unit, and a carboxyl oxgen from a symmetry-related unit. This pentagonal group is then transformed by a crystallographic rotation axis containing the K' ions to give the 10-co-ordinate unit. The K - * - 0 distances of the unit (Figure 12b), which may be described as an irregular pentagonal antiprism, range between 0.275 and 0.292 nm; the K' ion lies 0.155 nm from the least-squares plane of a pentagonal group of oxygen atoms.lS7 Phase transitions in potassium (T = 334 K) and rubidium (T = 320 K) acrylates have been established by wide-line n.m.r. and differential scanning calorimetry.'88 Transitions were not observed for Li and Na salts. The i.r. spectrum of HC0,K in KBr discs is ~ariable.'~' The spectra obtained all proved to be superpositions of two spectra, one due to the original solid, and the other to a transformation product, formed when pressure was applied. P. P. Saviotti and D. F. R. Gilson, J. Phys. Chem., 1976, SO, 1057 E. Spinner, Spectrochim. Acta, 1975, 31A, 1545. Elements of Group I 33 (a) (b) Figure 13 Crystal structure of the dehydrated Rb'-exchanged zeolite Rb,,NaA, showing (a) the unit cell, and (b) half of the large cage, within which the unco-ordinated ion, Rb(3), i s located (Reproduced by permission from J. Amer. Chem. SOC., 1976, 98, 5031) Electron microscopy of and a study of electron diffraction by a thin film of the complex formed between copper phthalocyanine and potassium have revealed a uni- que crystalline The electron micrographs showed that an island film structure existed, with single crystals of the complex being up to 1 grn in diameter. The films were stable in vucuo, but on exposure to air they degraded over a period of 24 hours, after which only traces of the ordered structure were observable by electron diffraction. Rubidium and Caesium Derivatives.-The existence of an unco-ordinated Rb' ion in a dehydrated Rb'-exchanged zeolite A (Rb,,NaA) has been rep~rted.~" In the structure (Figure 13a), eight of the eleven Rb' ions are distributed over four non-equivalent 3-fold axis points, while the remaining three, at Rb(2), lie at the centres of the %oxygen rings, The five Rb(1) ions are located in the large cavity, 0.125 nm from the O(3) planes of the 6-oxygen rings. Two non-equivalent Rb' ions, Rb(4) and Rb(5), are located inside the sodalite unit, near the 6-oxygen rings. Rb(3), the unco-ordinated ion, is deep within the large cavity, 0.367 nm from the O(3) plane (Figure 13b). Its closest approach to a framework oxygen (3 oxygen's of a 6-oxygen ring) is 0.435(8) nm, which is 0.156 nm greater than the sum of the corresponding ionic radii. These data substantiate the observation of under-co-ordinated large M' ions in the crystal structures of Cs,Na,A and K12A.19' The crystal and molecular structures of rubidium acid phthalate have been determined.192 The co-ordination around the Rb' ion is difficult to define. It is surrounded by oxygen atoms, the 6 nearest being between 0.280 and 0.306nm distant. There is, however, a seventh oxygen atom, located only 0.328 nmfrom the Rb' ion, and this structure is quoted as yet another example of the difficulty in J. R. Fryer and H. Murata, J. C. S. Chern. Comm., 1976, 499. lgl R. L. Firer and K. Seff, J. Amer. Chem. SOC., 1976, 98, 5031. lg2 R. A. Smith, Acta Cr yst ., 1975, B31, 2347. 190 34 Inorganic Chemistry of the Main-Group Elements assigning co-ordination numbers to these salts; a point first noted by T r ~ t e r . ~ ~ ~ The Cs' ion in caesium hydrogen acetylenedicarboxylate monohydrate is nine-co- ordinate, with Cs - - - 0 distances ranging from 0.331 to 0.340 nm; the crystals are monoclinic, space group C2/ c, with a = 1.276, b = 0.796, c = 0.679 nm, p = 92.27'.Ig4 193 M. R. Truter, Chem. i n Britain, 1971, 7, 203. 194 M. P. Gupta and A. P. Mahata, Cryst. Struct. Comm., 1976, 5, 557 2 Elements of Group II BY P. HUBBERSTEY 1 Introduction The chemistry of these elements will not be considered individually, as in previous Reports, but will be reviewed in sections covering particular aspects of the chemistry of the Group as a whole. For those topics which are common to Group I and I1 elements (e.g. cation solvation, molten salts, crown and cryptate com- plexes), the published data are reported in the relevant section in Chapter 1. The separation of isotopes of alkaline earth metals by ion-exchange chro- matography' (Be and Ca), using the band elution technique, and by chemical exchange reactions* (Ca), using macrocyclic polyether complexes, has been asses- sed. The separation factors for Be and Ca' decrease with increase in mass of the isotopes, and were found to be of the same order as those determined previously. Enrichment of the heavier isotopes of Ca by reaction (l), where L represents a macrocyclic polyether (e.g. DCH18C6, DB18C6), has also been shown to be effective.* 4 0 ~ a Z + (aq) +Wa( I J 2+ (org) .i- 44Ca2+ (aq) + 40Ca( ~) 2+ (org) (1) A sensitive and selective method for the spectrophotometric determination of Be with Chromazurol S and polyoxyethylenedodecylamine, in the presence of EDTA and Cloy, has been pr~posed;~ the effects of pH, of reagent concentra- tions, and of diverse cations and anions have been considered. A simple spectro- scopic method for the determination of traces of Mg has been de~el oped.~ Mg, in Titan Yellow solutions at pH 13.5, can be determined spectrophotometrically at 550nm; the influence of pH, of time, of wavelength, and of the presence of poly(viny1ic acid) has been assessed. In a study5 of the spectrophotometric determi- nation of Mg with Eriochrome Black T(EBT), the colour intensity of the Mg-EBT complex, in buffered solutions containing amines, has been found to depend on pH and on the nature and concentration of buffer used. The precipita- tion of Ba[(CO,),] from a homogeneous solution, by a diffusion technique using ammonia, has been advantageously utilized for the gravimetric estimation of Ba2+.6 Precipitation is slow in the presence of ammonia, and is quantitative D. A. Lee, J. Inorg. Nuclear Chem., 1976, 38, 161. B. E. Jepson and R. DeWitt, J. Inorg. Nuclear Chem., 1976, 38, 1175. H. Nishida, T. Nishida, and H. Ohtomo, Bull. Chem. SOC. Japan, 1976, 49, 571. C. Ducauze, Bull. Soc. chim. France, 1975, 1947. H. M. Sammour, R. M. Issa, F. M. Abdel-Gawad, and F. A. Aly, Indian J. Chem., 1976,14A, 289. ' K. S. Rao and V. G. Vaidya, Indian J. Chem., 1976, 14A, 217. 35 36 Inorganic Chemistry of the Main-Group Elements between pH 9.5 and 10.5; the effects of metal cations and of diverse anions have been elucidated. 2 Alloys and Intermetallic Compounds Transition Metals and Rare Earths.-Be,,Nb is a product of the reaction of Be with NbC0,78 at 1373 K;' conversely, the product of the corresponding reaction of Be with NbC,,,, is Be,C. Be and Y react at 973-1473 K to form Be13Y.' The kinetics of this reaction have been studied by the contact-couple method; the rate of reaction is governed by Y diffusion. The magnetic properties of Mg,M (M = La, Ce, Pr, Nd, Sm, Gd, or Tb) have been investigated (4-300K) at magnetic strengths up to 18 kOe.' Although they all adopt the cubic Fe,Al-type structure, they exhibit diverse magnetic properties; Mg,Smhas a Nkel temperature of 6.5 K, but no magnetic ordering was detected in Mg,M (M = Ce, Pr, or Nd). Mg,Gd and Mg,Tb apparently order ferromagnetically, with Curie temperatures of 117 and 108 K, respectively. Thermodynamic properties of Mg-Eu solutions have been deduced (953- 1003 K, 0.194s xMg s 0.945), using vapour-pressure techniques." The en- thalpy and entropy of formation of Mg2Eu (16.7 kJ mol-', 4.0 J K-' moll') from the solid components have been calculated and compared to those of Mg2Gd (19.7 kJ mol-', 2.5 J K-' mol-') and Mg2Nd (18.7 kJ mol-', 6.3 J K-' mol-l). The data for all three compounds are similar. Since Eu (unlike Gd and Nd) lacks a 5d' electron, it is concluded that the energy con- tribution of the 5d' electron to the Mg- - s M bond is small, and that these electrons do not take part in bond formation with Mg." A preliminary enthalpy study of solid Mg-Cd alloys (298-550 K, 0.193 S xaS 0.560) has been under- taken." Critical temperatures, order-disorder enthalpies of transformation, and molar heat capacities of alloys have been derived from the results.'l Main-Group Elements.-The structural chemistry of a number of boron-rich phases [including Mg2B14, MgA1Bl4, and Na,BB,, (0s x C l)] has been reviewed.', They crystallize in the orthorhombic space group Imam, with closely related lattice parameters and the same icosahedral boron skeleton. Single crystals of a compound denoted BeB, (of composition B 81.12%, Be 16.27%, Al 3.4-3.670) have been obtained from the reaction of Be with B in an A1melt at 1373 K;13 they have the same hexagonal unit-cell parameters (a = 0.9800, c = 0.9532 nm) as the previously designated BeB2.14 The unit cell of BeB, contains three BI2 icosahedra and further polyhedral units derived from icosahedral fragments consisting of B and Be atoms; the A1atoms occupy interstitial sites.', The crystal ' V. N. Zagryazkin and A. S. Panov, Russ. J. Phys. Chem., 1975, 49, 322. E. A. Vasina and A. S. Panov, Russ. J. Phys. Chem., 1975, 49, 427. K. €3. 3. Buschow, J. Less-Common Metals, 1976, 44, 301. lo A. P. Bayanov, Yu. A. Frolov, and Yu. A. Afanas'ov, Russ. J. Phys. Chem., 1975, 49, 1527. *' L. Charrin, R. Castenet, and M. Laffitte, Compt. rend., 1976, 282, C, 19 l2 R. Naslain, A. Guette, and P. Hagenmuller, J. Less-Common Metals, 1976, 47, 1. l 3 R. Mattes, K.-F. Tebbe, H. Neidhard, and H. Rethfeld, J. Less-Common Metals, 1976, 47, 29. l4 D. E. Sands, C. F. Cline, A. Zalkin, and C. L. Hoenig, Acta Cryst., 1961, 14, 309. Elements of Group I1 37 Table 1 Unit-cell parameters of alkaline-earth metals Symmetry cubic cubic hexagonal orthorhombic orthorhombic hexagonal tetragonal cubic monoclinic tetragonal monoclinic hexagonal monoclinic monoclinic tetragonal tetragonal - P21lc P Zl C P62m P21/m P2dm I4lmmm I4/mmm P4122 a number Structure type InCl InCl anti-PbClz CozSi Mn& - AuCU-I AuCuj - - anti-NiAs - of intermetallic phases containing alnm 1.2753 1.2484 0.6092 0.811 0.8035 0.9355 0.5118 0.4897 0.5144 0.5385 1.1985 0.7844 0.4746 0.4887 1.194 1.222 blnm clnm - - - - - 1.7782 0.515 0.954 0.5067 0.9617 - 0.7004 - 0.4491 0.5085 0.7526 - 1.5798 0.5806 1.8314 - 0.5917 0.4177 0.9084 0.4280 0.9177 - 1.740 - 1.779 - - B/" Ref. - 15 - 15 - 16 - 17 18 - 18 - 18 - 18 98.66 21 21 131.63 22 23 106.3 24 101.68 25 26 - 26 - - - - structures of SrAl,15 SrGa," and Ba4A1516 have also been determined; pertinent unit-cell parameters are collated in Table 1. The structures of SrAl and SrGa are closely related to that of cubic InCl,15 whereas those of Ba4A15 and the previously determined Ba7Al13 are similar to that of the Laves phase MgNi2.16 Single crystals of Sr,Si have been prepared;" they adopt the orthorhombic anti-PbCl, structure type (Table 1). The Ca-Pb phase diagram has been determined by thermal and X-ray methods." It contains four compounds, of which two melt congruently [Ca,Pb (m.pt. 1476 K) and CaPb, (m.pt. 939 K)], the others decomposing peritectically [Ca5Pb, (d., 1400 K) and CaPb (d.? 1241 K)]. The crystal structures of Ca,Pb, Ca,Pb,, and CaPb, were confirmed and CaPb was found to crystallize with the AuCu-I type structure; unit-cell parameters are collected in Table 1. The two eutectics occur at 90.5 mol YO Ca (1023 K) and 36.5 mol O/ O Ca (911 K).18 Single crystals of BeP, have been obtained by heating (to 1273K) Be-P mixtures (50 mol O/ O P).19 The X-ray powder diffraction pattern of this chemically very stable compound can be indexed with cell parameters a=b=0.3546, c = 1.501 nm; preliminary structural studies, however, show that the unit cell is probably larger, MgP,,' has been prepared by heating Mg filings with red P in the presence of trace amounts of I2 or S; it may be separated from the reaction mixture by semi-concentrated mineral acids. It is isotypic with CdP,, with Mg atoms octahedrally co-ordinated by P atoms and P atoms tetrahedrally co-ordinated by both Mg and P atoms (Mg.-.P=0.2608-0.2862nm; P- .-P=O.2184- 0.2252 nrn).,' MgAs, has also been prepared in powder and crystalline form;21 its tetragonal unit-cell parameters are contrasted with the monoclinic data for MgP, in Table 1. M. L. Fornasini and F. Merlo, Acta Cryst., 1976, B32, 1864. l6 M. L. Fornasini, Acta Cr y s t . , 1975, B31, 2551. '' A. Widera, B. Eisenmann, and H. Schafer, Z. Naturforsch., 1976, 31b, 520. G. Bruzzone and F. Merlo, J. Less-Common Metals, 1976, 48, 103. l9 J. David and J. Lang, Compt. rend., 1976, 282, C, 43. 2o H. G. von Schnering and G. Menge, Z. anorg. Chem., 1976, 422, 219. 21 R. Gerardin, M. Zanne, A. Courtois, and J. Aubry, Compt. rend., 1976, 283, C, 135. 38 Inorganic Chemistry of the Main-Group Elements Figure 1 Co-ordination polyhedron of the calcium atom in CaSb,; open circles are calcium (Reproduced by permission from 2. anorg. Chem., 1976, 425, 104) and cross-hatched ones antimony Crystal structure data for Ca2As3,” C ~A S? ~ CaSb2,24 SrSb2?5 CallSbl,,26 and Ca, ,Bi,,26 have been elucidated; their relevant unit-cell parameters are collected in Table 1. Ca2As;2 and MSb,24,25 belong to the group of Zintl phases. The co-ordination polyhedra of the alkaline-earth-metal atoms are complex in all of these compounds,22-26 the co-ordinating atoms being a mixture of metal and Group V element atoms; a typical polyhedron (for Ca in CaSb,) is shown in Figure 1; it consists of ten Sb atoms and four Ca atoms with Ca. - -Sb and Ca . . - Ca distances in the ranges 0.29-0.38 and 0.36-0.44 nm, re~pecti vel y.~~ 3 Binary Compounds In this section, the chemistry of oxides, halides, and similar species will be considered; the majority of the papers abstracted reflect the growing interest in MgO as a catalyst. Oxides, Sulphides, and Related Speaes.-The kinetics of the formation of MgO in the diffusion zone of a flame [reaction (2)] have been studied at pressures up to 10 mmHg in the temperature range 773-1023 K.27*28 The reaction takes place in two stages (3) and (4), of which the former is rate-determining; the homogeneous condensation of MgO has practically no effect on the reaction.” Mm +@,(g) + MgO(g) (2) Mgk) + 0 2 (gi -+MgO (g) + 0 (g) (3) Mg(g) +O(g) + MgO(g) (4) A simple M.O. model for bonding in MgO has been developed, using Mg40, (a cube with Mg and 0 atoms at alternate corners) as a basis.29 Extension to Mg32032 22 K. Deller and B. Eisenmann, Z. Naturforsch., 1976, 31b, 1023. 24 K. Deller and B. Eisenmann, Z. anorg. Chem., 1976, 425, 104. ” K. Deller and B. Eisenmann, 2. Narurforsch., 1976, 31b, 1146. 26 K. Deller and B. Eisenmann, 2. Nafurforsch., 1976, 31b, 29. 2’ 0. E. Kashireninov, V. A. Kuznetsov, and G. B. Manelis, Russ. J. Phys. Chem., 1975,49,520. 28 0. E. Kashueninov, V. A. Kuznetsov, and G. B. Manelis, Russ. J. Phys. Chem., 1975, 49,454. 29 C. J. Nicholls and D. S. Urch, J.C.S. Dalton, 1975, 2143. P. L‘Haridon, J. Guyader, and M. Hamon, Rev. Chim. minerale, 1976, 13, 185. 23 Elements of Group I1 39 shows how the M.O. description can be developed into the band structure for MgO. The model provides an adequate representation of the principal features of the X-ray emission (Mg-K&3, Mg-L2,3M, and 0-Ka) and X-ray photoelectron spectra of Mg0.29 Surface states on Mg030731 and Ca03’ have been studied by u.v.-v~s.~’ and i ~. ~’ diffuse reflectance spectroscopy. The effect of outgassing (773-1073 K) is to develop U.V. absorption bands in the range 30 000-50 000 ~m- ~. ~’ These bands have been attributed to absorptions at surface oxide sites in different states of co-ordinative unsaturation, the lower energy band corresponding to lower co- ordination. A theory has been developed for the surface centre in MgO; the defect consists of an electron trapped at an anion vacancy on a (001) surface.32 Differences in the surface and catalytic properties of MgO samples prepared by decomposition of the hydroxide and the carbonate hydroxide have been estab- l i ~hed; ~~ the kinetics of the thermal decomposition of Mg(OH), have also been dete~rnined.’~Typical examples of adsorption studies on MgO surfaces are provided by i.r. investigations of adsorbed acetone3’ and methyl fl u~rosul phate~~ vapours and e.s.r. studies of the dimerization of pyridine derivatives” and the formation of the paramagnetic ion S20- (by reaction of H,S and SO,).’” Decom- position reactions on MgO surfaces are typified by the adsorption and consequent breakdown of N20 on both y-irradiated Mg039 and pure and Li20-doped MgO-Fe,O, solid ~01ut i o n~~~~~~ and of propan-2-01 on pure and Li,O-doped MgO Hydrogen-deuterium exchange reactions of benzene and alkyl- benzenes: isomerization of butene~, ~~ and hydrogenation of buta- 1 ,3-diene45 have also been effected on MgO surfaces. The hydrogenation reaction is novel, since the catalyst did not show any activity for H2-D2 equilibration, but was active and highly selective for hydrogenation of buta-1,3-diene to cis-b~t-2-ene.~’ The formation of Yb2+and of Eu2+in CaO has been established in diffuse reflectance spectroscopy experi ment~.~~ Interest in these materials, which were produced by the reduction of M,03 with Ca vapour, arises from their application as laser or photochromic materials.46 Single crystals of Bas, have been obtained by heating 1 : 1 Bas : S mixtures up to 1073 K in a graphite tube;47 they are monoclinic, of space group C2/c, with unit-cell parameters a = 0.9299, b = 0.4736, c = 0.8993 nm, p = 118.37”. The 30 A. Zecchina, M. G. Lofthouse, and F. S. Stone, J.C.S. Faraday I, 1975, 71, 1476. 31 N. Takezawa and H. Kobayashi, Bull. Chem. SOC. Japan, 1975, 48, 2250. 32 R. R. Sharma and A. M. Stoneham, J.C.S. Faraday XI, 1976, 72, 913. 33 H. Hattori, K. Shimazu, N. Yoshii, and K. Tanabe, Bull. Chem. SOC. Japan, 1976, 49, 969. 34 S. B. Kanungo, Indian J. Chem., 1975,13, 180. 35 F. Koubowetz, H. Noller, and J . Latzel, Z. Naturforsch., 1976, 314 922. 36 D. D. Eley, G. M. Kiwanuka, and C. H. Rochester, J.C.S. Faraday I, 1976, 72, 876. 37 T. Iizuka and K. Tanabe, Bull. Chem. SOC. Japan., 1975, 48, 2527. 38 M. J. Lin and J . H. Lunsford, J. Phys. Chem., 1976, 80,635. 39 R. J. Breakspere, L. A. R. Hassan, and D. K. Roberts, J.C.S. Faraday I, 1975, 71, 2251. 40 M. Valigi, F. Pepe, and M. Schiavello, J.C.S. Faraday I, 1975, 71, 1631. 41 M. Schiavello, M. Valigi, and F. Pepe, J.C.S. Faraday I, 1975, 71, 1642. 42 I. M. Hoodless and G. D. Martin, Canad. J. Chem., 1975, 53, 2729. 43 M. S. Scurrell and C. Kemball, J.C.S. Faraday I, 1976, 72, 818. 44 J. L. Lemberton, G. Perot, M. Guisnet, and R. Maurel, Bull. Soc. chim. France, 1976, 359. 45 H. Hattori, Y. Tanake, and K. Tanabe, J. Amer. Chem. Soc., 1976, 98,4652. 46 D. Bruning, H. Ihle, and E. Langenscheidt, J. Inorg. Nuclear Chem., 1976, 38, 602. 47 I. Kawada, K. Kato, and S. Yamaoka, Acta Cryst., 1976, B31, 2905. 40 Inorganic Chemistry of the Main-Group Elements Sg- ions (S 9 - - S distance = 0.2118 nm) form arrays parallel to (110); Ba2’ ions are located between these arrays, and they co-ordinate to 8 sulphur atoms, with Ba - - S distances ranging from 0.3151 to 0.3223 nm.47 Raman studies (148- 853 K) have been effected on Halides.-The kinetics of crystallization of vitreous BeF, have been studied, using X-ray diffraction and calorimetric An analysis of the data shows that the crystallization proceeds via spherulitic growth, with an activation energy of 222 kJ mo1-l. The enthalpy increments of BeF, have been measured by the drop method, in both the glassy and liquid states, from 450 to 914K5’ The adsorption of H,O vapour by MgF, has been studied, using vapour- pressure and i.r.-spectroscopic technique^.^' Crystalline samples of, inter alia, CaF, and BaF, have been prepared by precipitation from aqueous media.’, An i.r. examination of CaF, and BaF, pressed discs showed that both materials contained occluded H,O ; both compounds were completely cleared of i.r. bands in the 3000-4000 cn-’ region by evacuation at 633 K. Analysis of the results indicates that, whereas CaF, can bind H,O molecules relatively strongly, BaF, cannot similarly bind H,O molecules, and adsorption on this surface is due solely to a physisorption pro~ess.’~ 4 Ternary Compounds For the purposes of this Report, ternary compounds are restricted to derivatives of the types MMLH,, MMLO,, and MM:X,, where M is a counter-cation (usually an alkali-metal ion), M‘ is an alkaline-earth metal, and X is a halogen. Hydrides.-Complex metal hydrides of Be have been prepared by the reaction of LiAlH, and AlH, with ‘ate’ complexes of Be, [Li,Be,R,,+,], in ether Both [LiBe(CH,),] and [Li,Be(CH,),] yielded Li,BeH, when treated with LiAlH, in Et,O. Li,BeH, was obtained by the reaction of [Li,Be(CH,),] with LiAlH, in Et,O. [LiBe,(CH,),] yielded a compound of indefinite composition. LiBeH, was prepared by the reaction of AlH, and [LiBe(CH,),] in a 1 : 1 molar ratio in Et,O. The hydrides were characterized by elemental analysis, X-ray powder diffraction, and d. t.a.-t.g.a. anal~sis.’~ Oxides.-The electronic structures of MgOz- and of the isoelectronic moieties A10:- and have been calculated, using the SCF X, scattered-wave cluster M.O. rneth~d.’ ~ The orbital energies of MgOz- are in agreement with experimen- tal data for minerals containing this anion; it has been postulated that the observed instability of MgO2- is associated with the high energy of the 5a,, Si 3s-0 2p bonding M.O.’, The existence of the alkali-metal beryllates K2Be203 (2 forms), K,BeO,, Rb,Be,O,, Rb,Be,O,, Rb,BeO,, Cs,Be,O,, and Cs,BeO, has 4R G. J. Jam, E. Roduner, J. W. Coutts, and J. R. Downey, Inorg. Chern., 1976, 15, 1751. 49 S. Tamura and T. Yokokawa, Bull. Chem. SOC. Japan, 1976, 49,423. 51 P. B. Barraclough and P. G. Hall, J.C.S. Faraday I, 1976, 72, 610. ” P. B. Barraclough and P. G. Hall, J.C.S. Faraday I, 1975, 71, 2266. 53 E. C. Ashby and H. S. Prasad, Inorg. Chem., 1975, 14, 2869. 54 J. A. Tossell, J. Amer. Chem. Soc., 1975, 97,4840. S. Tamura and T. Yokokawa, Bull. Chem. SOC. Japan, 1975,48, 2542. Elements of Group II 41 Table 2 Unit-cell parameters for several alkali-metal ber yl i at e~~~ Compound Symmetry alnm blnm c/nm a/" @/" y/" Li4Be 0, triclinic 0.549 0.953 0.493 114 105 106 Na,Be,O, triclinic 0.632 0.853 0.271 107 105 78 K,BeO, monoclinic 0.709 1.057 0.570 - - 131 Rb,BeO, monoclinic 0.746 1.117 0.588 - - 131 Na,Be,O, tetragonal 0.567 - 1.020 - - been proven from X-ray powder diffraction data.55 Single crystals of Li,BeO,, Na2Be20,, N%Be,O,, K,BeO,, and Rb2Be0, have been obtained; their unit-cell parameters are collected in Table 2? Halides.-The synthesis of the fluorometallates MM'F, or M2M'F4 (M = alkali metal, M' = alkaline-earth metal) has been achieved by the action of SF, on M'O in the presence of MF.56 KMgF,, CsSrF,, and LiBaF, were prepared and characterized; also obtained were K2MgF4, CsMgF,, Cs2MgF4, and CsCaF,. The conditions governing their synthesis have been determined by differential scan- ning thermography (673-1013 K). The BeCl2-RbClS7 and MgC12-NaC15, phase diagrams have been determined in detail, using d.t.a. techniques. The phase equilibria are summarized and compared in Figure 2. Whereas two congruently melting compounds (Rb2BeC1, and RbBe2C1,) are found in the former system, four peritectically decomposing compounds (Na,MgCl,, Na,MgCl,, NaMgCl,, and Na2Mg,C1,) occur in the latter system. Phase relationships have also been established in the Li, Na, Sr 11 Cl,s9 Li, Na, Ba 11 Cl,59 Rb, Ca 11 F, C1,60Li, K, Ca, Ball F, Cl,,l and Na, K, Ca, Ba )I F, C161 systems. The structural chemistry of ternary halides has been the subject of four paper^.^^-,^ Single-crystal X-ray diffraction data have been obtained for RbMgCl,,,' CUB~F,,~H,O,~~ and RbLi,Be,F,,64 and Raman spectra of oriented single crystals of K2MgC1,6' and C S ~M ~C ~, ~~ have been measured. Relevant structural data are collected in Table 3. Whereas RbMgC1, contains pairs of face-sharing octahedra, connected at the corners to give six-co-ordinate Mg, in CuBeF4,5H20 the Be atoms are tetrahedrally surrounded by four F atoms (Be - - - F distance = 0.155 nm). RbLi2Be2F7 consists of six-membered rings of BeF, and LiF, tetrahedra, linked to form an elongated chain structure; the Rb' ions lie inside the ring holes. The Raman studies,' show that whereas in K2MgC14 the Mg is surrounded by six C1atoms in a distorted octahedral arrangement, with a network structure such that neighbouring octahedra share corners, a discrete MgC1:- species is present in Cs2MgC14. Raman spectra of the high-temperature solids and molten salts suggest that the co-ordination of Mg changes from 6 in P. Kastner and R. Hoppe, 2. anorg. Chem., 1975, 415, 249. 20, 1287. H.-J. Seifert and H. Fink, Rev. Chim. minerale, 1975, 12, 466. 55 " A. A. Opalovskii, E. V. Lobkov, Yu. V. Zakhar'ev, and L. K. Kamenek, Russ. J. Inorg. Chem., 1975, 57 B. P. Podafa, P. G. Dubovoi, and V. T. Barchuk, Russ. J. Inorg. Chem., 1975, 20, 1271. 59 G. A. Bukhalova, V. M. Burlakova, and D. V. Sementsova, Russ. J. Inorg. Chem., 1975, 20,928. 'O G. A. Bukhalova, V. T. Berezhnaya, and G. N. Litvinova, Russ. J. Inorg. Chem., 1975, 20, 1372. '' N. M. Mirsoyanova and G. A. Bukhalova, Russ. J. Inorg. Chem., 1975, 20, 1353. 62 H.-J. Seifert and H. Fink, Rev. Chim. minerale, 1975, 12, 466. 64 J. Vicat, D. Tran Qui, and S. Aleonard, Acta Cryst., 1976, B32, 1356. 65 M. H. Brooker, J. Chem. Phys., 1975, 63, 3054. A. D. van Ingen Schenau, G. C. Verschoor, and R. A. G. de Graaf, Acra Cryst., 1976, B32,1127. 1 1 0 0 1 1 1 0 7 3 1 1 0 0 0 - X 8 0 0 - ! ! E 7 0 0 - 8 \ 3 Y < E G 6 0 0 m a - 5 0 0 p - R b C t 2 0 1 1 0 0 4 0 6 0 8 0 B e C I 2 N a C I 2 0 4 0 6 0 8 0 M g C I 2 m o l ' 1 0 B e C I , m o t '1 ' M g C I , C o m p o s i t i o n F i g u r e 2 P h a s e d i a g r a m s o f ( a ) B e C I , - R b C l a n d ( b ) M g C 1 , - N a C l s y s t e m s [ R e p r o d u c e d b y p e r m i s s i o n f r o m ( a ) R u s s . J . I n o r g . C h e m . , 1 9 7 5 , 2 0 , 1 2 7 1 , a n d ( b ) R e v . C h i r n . m i n e r u l e , 1 9 7 5 , 1 2 , 4 6 6 1 P F 3 Elements of Group II 43 Table 3 Unit-cell parameters for a number of ternary halides Space Symmetry group alnm blnm clnm a/" B/" yIo - - RbMgC1362 hexagonal P6Jmmc 0.7090 - 1.1844 - RbLizBezF764 monoclinic P2,lc 1.2376 0.4948 1.0054 - 90.25 - CuBeF4,5Hz06' triclinic pi 0.7132 1.0674 0.5924 97.53 125.49 93.94 solid K2MgCl, to 4 in the melt, whereas Cs2MgC1, melts with retention of the MgC1;- complex .6 5 Compounds containing Organic or Complex Ions Beryllium Derivatives.-The preparation of Be(B3H& from TlB3H8 and BeCl, has been reported.66 Its low-temperature static configuration and intermediate- and high-temperature fluxional forms have been identified from a study of its 'H n.m.r. and "B F.T. n.m.r. spectra;66 its molecular structure at low tempera- tures (Figure 3) has been confirmed in a single-crystal X-ray diffraction It consists of two bidentate B3H; ligands bound to a central Be atom by two Be- H-B bridge hydrogen bonds from adjacent B atoms in each B3H8 moiety. The molecule has molecular C2 symmetry, with an approximately tetrahedral Be atom.67 The reaction of Be(BH,), with ClB5H8 results in insertion of a Be atom into the borane cage to give B5HloBeBH4.68 The product (m.pt. 25 1 K) is thermally stable at room temperature, but is expected to be sensitive to air and moisture. Further details, and a Figure illustrating its molecular structure, are given in Chapter 3. The molecular structure of CH3BeBH4 (1) has been inferred from an analysis of vapour-pressure data and of vapour- and solid-phase vibrational s~ectra.6~ CH,BeBH, is dhneric in both the vapour and solid phases; the BHT moiety is attached to the Be atom by a double hydrogen bridge and the two CH3BeBH4 fragments are linked by two bridging CH3 units.69 Vibrational spectra Figure 3 The static molecular smcture of Be(B3H,), (Reproduced by permission from J. Amer. Chern. SOC., 1976, 98, 5489) 66 D. F. Gaines and J. H. Morris, J.C.S. Chem. Comm., 1975, 626. 67 J . C. Calabrese, D. F. Gaines, S. J. Hildebrandt, and J. H. Moms, J. Amer. Chem. Soc., 1976, 98, 68 D. F. Gaines and J . L. Walsh, J.C.S. Chem. Comm., 1976, 482. 69 L. J . Allamandola and J. W. Nibler, J. Amer, Chem. Soc., 1976, 98, 2096. 5489. 44 Inorganic Chemistry of the Main-Group Elements have also been communicated for liquid and solid C5H5BeBH4:’ evidence for a double hydrogen bridge configuration is found for C,H,BeBH4, and, in contrast to Be(BH,),, this structure is unchanged in going from gaseous to liquid to solid phases.” ‘H n.m.r. CF,Cl, spectra of beryllocene have been measured (138-223 K):l it was found to be impossible to conclude from the data whether beryllocene i s a slip sandwich or a symmetrical top in solution (cf. the slip-sandwich configuration in the solid phase), but the barrier height must be below 138K. 71 An X-ray crystal-structure analysis of the dimer [Be(N=CBu~),],, prepared from BuiC==NH and Pr2Be in Et,O, shows that it adopts a structure (Figure 4) containing both bridging and terminal methyleneamino-groups, the latter being attached to the three-co-ordinate Be atoms by Be - - . N bonds that are only 0.150nm long; the shortest yet reported for a solid Be-N The chemistry of alkali-metal tetramonocarboxylatoberyllates M,[Be(RCO,),] (M=Na, K, Rb, or Cs) has been extended to include acetate, formate, mono- chloroacetate , N-substituted propionate, butyrate, and benzoate ligand~.~’ Beryllium chelates of acetoacetamides n react with N-iodosuccinimide (in n O C CHCl,) and 0.168; Be-N, Figure 4 Skeleton of [Be(N=CBui),],. Interatomic distunceslnm are: Be-N, 0.150; C=N, 0.128; C=N, 0.127; Be. * . Be 0.223. Bond anglesl” are: Be-Np- Be’ 83; N,-Be-NI 97; Be’. * -Be-N, 161; Be-N,=C 161; N,-Be-N, 129; Be-N,=C 138. (Reproduced from J.C.S. Chem. Cornm., 1976, 160) ’ O D. A. Coe, J. W. Nibler, T. H. Cook, D. Drew, and G. L. Morgan, J. Chem. Phys., 1975,63,4842. 71 C.-H. Wong and S.-M. Wang, Inorg. Nuclear Chem. Letters, 1975, 11, 677. 72 J. B. Farmer, H. M. M. Shearer, J. D. Sowerby, and K. Wade, J.C.S. Gem. Comm., 1976, 160. 73 A. K. Sengupta and S. K. Adhikari, J. Inorg. Nuclear Chem., 1976, 38, 1228. Elements of Group II 45 thiocyanogen (in CH2C12), yielding the corresponding iodo- and thiocyanato- i.r. and 'H n.m.r. studies show that electrophilic substitution occurs at the central C atom of the chelate ring. Chelation of Be2' ions by histidine has been achieved in the system histidine (HA)-Be2+-H20 (NaClO,, 0.5 mol l-l, 298 K);75 the complexes [Be(H2A)I3+and [Be(HA)I2+and the hydroxylated species [Be,(OH),(H,A)T+, [Be,(OH),(HA)l3', [Be3(0H),(HA),l3+, and [Be,(OH),(HA),]3' have been identified by p~tenti ometry.~~ Magnesium Derivatives.-Models for the role of Mg2+in enzymic synthesis have been de~eloped.'~,~~ The effect of Mg2' ion on the general base-catalysed enoli- zation of methyl acetonylphosphonate has been as~ertai ned.~~ The effectiveness of Mg2+as a template for the synthesis of planar N-donor macrocycles (2) and (3), which are of interest in the biosynthesis of porphyrins and the activation of enzymes, has been established ;77 pentagonal-bipyramidal complexes [Mg(macrocycle) (H20)2]2+are formed by condensation of 2,6-diacetylpyPidine with a linear tetramine in the presence of Mg2+. Single-crystal data for Mg(macrocyc1e (2)}C12,6H20 define the pentagonal-bipyramidal geometry; the Mg- - - N distances range from 0.224 to 0.231 nm; Mg. * - 0 distances are 0.210 nln.77 (2) n = 2 (3) n = 3 The pseudo-octahedral complex (4) has been produced by aerial oxidation of 3,5-di-t-butylcatechol in the presence of ammonia and Mg2+.78 It is also formed (4) 74 J. N. Patil and D. N. Sen, Indian J. Chem., 1975,13,291. 76 R. Kluger and A. Wayda, Canad. J. Chem., 1975, 53,2354. 77 M. G. B. Drew, A. Hamid bin Othman, S. G. McFall, and S. M. Nelson, J.C.S. Chem. Comm., 1975, G. Duc, F. Berth, and G. Thomas-David, Bull. Soc. chim. France, 1976, 414. 75 818. A. Y. Gugis and A. L. Balch, Inorg. Chem., 1975, 14, 2724. 46 Inorganic Chemistry of the Main - Group Elements in the reaction of Mg2+with 3,5-di-t-butylcatechol, 3,5-di-t-butyl-1,2-quinone, and ammonia in the absence of air.7g A novel Mg" co-ordination complex with HCN as N-donor ligand, [Mg(NCH),] (InCl,),, has been it is prepared by treating MgCl, with InCl, in a 1 : 2 ratio in liquid HCN at 288 K under anhydrous conditions. The Mg2+is surrounded by six HCN molecules in a regular octahedral array; whereas vCN (2132cm-') and SHCN (778cm-I) are shifted to higher frequency, vCH (3164cm-') is shifted to lower frequency with respect to these vibrations in gaseous HCN (2097, 713, and 3311 cm-', re~pectively).'~ The crystal structure of the 1 : 1 adduct of 1,4-dioxan with [Mg(H,O),]Cl, has been determined The 1,4-dioxan moieties form extended hydrogen-bonded networks between the H,O molecules co-ordinated to the metal atoms. The thermal decomposition characteristics of this adduct, the parent complex [Mg(H,0)6]Cl,, and the bis-adduct MgCl,,( 1,4-dioxan), have been studied by differential enthalpic analysis, by thermogravimetry, and by dynamic reflectance spectroscopy.81 Whereas MgC12,( 1,4-dioxan), decomposes to MgC12 in a single endotherm, peaking at 463 K, the decomposition of the hexa-aquo complexes is much more complex, passing through a number of intermediate stages, and is very sensitive to changes in experimental conditions." Detailed analyses of aspects of the vibrational spectra of the octahedral moieties [Mg(H20)6]2+82 and [Mg(NH3)6]2+ 83 have been effected. Five co-ordinate complexes of Mg2+and Ca" with simple unidentate ligands of the type R3X0 ( X=P or As), e.g. [M(M~,AsO),](C~O,)~ (M=Mg or Ca), have been obtained by mixing triethyl orthoformate-methanol solutions of the appropriate perchlorate and phosphine or arsine Although the reactions were carried out in the presence of the dehydrating agent triethyl orthoformate, H20 was not eliminated from the co-ordination sphere in all cases, and six-co-ordinate compounds, e. g. [M(Me,PO),,H,0](C104)2, were formed. The biochemical implications of the possibility of changes of the co-ordination of the complexes by addition and removal of a ligand such as H20 have been discus- ~e d . ~~ The crystal structure of [Mg(Me,AsO),](C104), (and of its Ni analogue) has been determined by single-crystal X-ray diffraction methods.85 It consists of discrete [Mg(Me,As0),12' cations (Figure 5) , well separated from ClO, ions; the co-ordination about Mg2+is nearly square pyramidal, with the Mg atoms 0.0454 nm above the least-squares plane of basal oxygen and arsenic atoms. The structure of Mg(HC0,),,2H20, as proposed by Osaki et uZ. , ' ~ has been proved to be correct in a redetermination of the crystal structure at 130 and 293 K by de With et ~ 1 . ' ~ Two types of octahedrally co-ordinated Mg2+ ion are observed; Mg(1) is surromded by six oxygen atoms of different formate ions, 7y P. L. A. Everstein, A. P. Zuur, and W. L. Dreissen, Znorg. Nuclear Chem. Letters, 1976, 12, 277. J. C. Barnes and T. J. R. Weakley, J.C.S. Dalton, 1976, 1786. J. C. Barnes, Znorg. Nuclear Chem. Letters, 1976, 12, 89. '* J. T. Bulmer, D. E. Irish, and L. Odberg, Cunad. J. Chem., 1975, 53, 3806. 83 R. Plus, Spectrochim. Acta, 1976, 32A, 263. 84 G. B. Jameson and G. A. Rodley, Znorg. Nuclear Chem. Letters, 1975, 11, 547. Y. S. Ng, G. A. Rodley, and W. T. Robinson, Inorg. Chem., 1976, 15, 303. 86 K. Osaki, Y. Nakai, and T. Wanabe, J. Phys. SOC. Japan, 1964, 19, 717. '' G. deWith, S. Harkema, and G. J. van Hummel, Acta Cryst., 1976, B32, 1980. 85 Elements of Group I . c 51 47 Figure 5 Perspective view of the [Mg(kle,A~O),]~+ cation (Reproduced by permission from Inorg. Chem., 1976, 15, 303) whereas Mg(2) is surrounded by four water oxygen atoms and two oxygen atoms of formate groups. Mg - - * O bond distances/nm and 0-Mg-0 bond anglesl” in the Mg(1) [and Mg(2)] oxygen octahedron vary from 0.2056 to 0.2108 (0.2051 to 0.2118) and from 88.29 to 91.99 (78.83 to 93-82], respectively, at 293 K.” The i.r. spectra of crystalline M(CF,CO,), (M=Mg or Ca) have been measured between 300 and 400~m- ~; ~~ the CF,CO, group vibrations were found to be influenced more by mass and steric hindrance of the CF, groups than by the electron-withdrawing ability of the fluorines. Thermal decomposition of, inter alia, MgC(CH,CO,),] has been investigated by a number of physicochemical techni- q u e~. ~~ Residues were composed of MgO and some c; a wide range of gaseous products, but predominantly CO,, was observed. Complex formation between M2+(M = Mg, Ca, Sr, or Ba) and 1,3-diamino-2- h ydroxypropane - NN‘-dimalonic acid ,90 N- (car box yme t h yl) asp ar tic acid ,” NN - bis(carboxymethy1)aspartic acid: and thiophen-2-carboxylic acid9, in aqueous solutions has been the subject of four separate investigations; in general, the stability of the complexes decreases as the cationic radius is increased.’’ Tris(hexafluoroacety1acetonato) complexes of M2+ (M = Mg, Ca, Sr, or Ba) have been prepared by the reaction of MC1, with the chelating agent in buffered (Na acetate) non-aqueous media.94 Mg2+formed the 1 : 2 chelate Mg(hfa),, whereas the heavier metals form 1 : 3 chelates Na[M(hfa),] (M = Ca, Sr, or Ba). That Mg is an exception is not surprising, due to the relatively small size of the ion and the ” J. A. Faniran and K. S. Patel, Spectrochim. Acta, 1976, 324 1351. 89 H. Yokobayashi, K. Nagase, and K. Muraishi, Bull. Chem. Soc. Japan, 1975, 48, 2789. 90 A. I. Kapustnikov and I. P. Gorelov, Russ. J. Inorg. Chem., 1975, 20, 506. 91 I. P. Gorelov and V. M. Nikol’skii, Russ. J. Inorg. Chem., 1975, 20, 966. 9z V. M. Nikol’skii and I. P. Gorelov, Russ. J. Znorg. Chem., 1975, 20, 1764. 93 S. S. Sandau, R. S. Sandau, and J. N Kumaria, Indian J. Chem., 1976, 14A, 366. 94 M. Janghoroani, E.Welz, and K. Starke, J. Znorg. Nuclear Chem., 1976, 38, 41. 48 Inorganic Chemistry of the Main -Group Elements Figure 6 Molecular structure of Mg,Br,(THF),(p -N=CPhZ),-(~ -THF). Interatomic distanceslnm are: Mg-N 0.208; Mg-Br 0.247; Mg-0, 0.207; Mg-0, 0.245; C=N 0.126; Mg. ‘Mg 0.289. Bond angle$ are: Mg-N-Mg 88.0; N-Mg-N 89.0; Mg-O,-Mg 72.1; Br-Mg-0, 96.6; Br-Mg-0, 87.4; O,-Mg-O, 173.1. (Reproduced from J.C.S. Chern. Comm., 1976, 107) well-known chemical dissimilarity between Mg and the heavier metals. Evidence for conformational equilibrium in magnesium acetylacetonate has been derived from its ‘Hn.m.r. (CDC13) ~pectra;~’ resonances due to the methyl protons of both D,, (121 Hz) and R2,, (108 Hz) conformers were observed, together with that for the ring proton (331 Hz). In DMSO, acetone, dioxan, and pyridine, the data are consistent with the presence of a DZh isomer only; these solvents probably co-ordinate directly to the axial positions of the & isomer, thereby preventing conformational equilibrium.’’ Two “HF adducts of diphenylmethyleneaminomagnesium bromide, of formulae Mg,Br,(N=CPh,)(THF), and Mg2Br2(N=CPh2)2(THF)2, have been isolated.96 An X-ray crystallographic study of the former (Figure 6) has shown it to contain bridging THF molecules, attached to the Mg atoms by unusually long bonds; all relevant molecular structural features are given in the legend to the Figure. One of the THF molecules, presumably the bridging one, can be removed either under reduced pressure or by dissolution in benzene. The residual Mg,Br,?(N=CPh,),(THF), gives a different X-ray powder difiaction pattern, and presumably has structure ( 5) . Hexaborane( 10) has been deprotonated by methylmagnesium halides and di- methylmagnesium, to form Mg(B,H9),(THF),.97 The Mg2+ion is co-ordinated to ’’ H. G. Brittain, I mr g . Chem., 1975, 14, 2858. “ K. Manning, E. A. Petch, H. M. M. Shearer, K. Wade, and G. Whitehead, J.C.S. Chem. Comm., ’’ D. L. Denton, W. R. Clayton, M. Mangion, S. G. Shore, and E. A. Meyers, Inorg. Chem., 1976,15, 1976, 107. 541. Elements of Group I . 49 each B,H; anion through one of the latter's two non-adjacent basal B-B bonds. The six-fold co-ordination of the Mg atom is completed by two oxygen atoms of separate THF molecules. The Mg- - - B distance varies from 0.238 to 0,248 nm and the Mg...O distances are 0.2019nm; the arrangement of each B6 framework, with respect to Mg in the structure, is consistent with Mg being inserted into one of the B-B bonds of each framework to form three-centre B- Mg-B bonds." Several facile synthetic routes have been reported for the preparation of a wide variety of transition-metal carbonyl derivatives of Mg;98 a typical preparation [equation ( 5) ] involves reductive cleavage of dheri c transition-metal carbonyl EFe(CO),(C,H,)I, +Mg(Hg) B,Mg[Fe(CO),(CSHs)I2 ( 5 ) complexes with a dilute Mg amalgam, in the presence of a Lewis base (B is THF, pyridine, or tetramethylethylenediamine). The number of co-ordinated Lewis bases is variable, leading to co-ordination numbers of either 6 ( x = 4) or 4 (x = 2). Six-co-ordinate Mg complexes invariably involve CO bridges, Mg-O=C--M; four-co-ordinate Mg complexes, depending on the nucleophilicity of the transition-metal carbonyl anion, can possess either CO bridges or a direct Mg-M bond?8 Calcium Derivatives.-A considerable proportion of the data abstracted for this section of the Report describe the interactions of Ca2+ions with carbohydrate derivative^.^^-'^The crystal and molecular structures of CaBr,-P -D-fructose di h~drate?~ of Ca-D-glucarate tetrahydrate,'" of Ca-2-keto-~-gluconate trihyd- rate,'" and of Ca,Na-a-D-galacturonate hexahydratelo2 have been ascertained; the chemical formulae and atomic numbering of the carbohydrate derivatives are shown in Figure 7. The co-ordination number of the Ca2'ion varies markedly; whereas it is 7 in the fructose derivative, it is 8 in the glucarate (Figure 8a) and 9 in the gluconate (Figure 8b) and galacturonate. In the fructose derivative, the Ca2+ion is co-ordhated to three fructose moieties through their O(2) and 0(3), O(4) and 0 ( 5 ) , and 0(1) hydroxy-groups, respectively, and to two water oxygen The seven oxygen atoms assume a pentagonal-bipyramidal arrangement, with Ca * * * 0 distances ranging from 0.232 to 0.247 nm. The eight-co-ordinate Ca2' ion of the glucarate is in a distorted square antiprismatic geometry provided 98 G. B. McVicker, Inorg. Chem., 1975, 14, 2087. 99 W. J. Cook and C. E. Bugg, Acru Cryst., 1976, B32, 656. loo T. Taga and K. Osaki, Bull. Chem. Soc. Japan, 1976, 49, 1517. 'O' M. A. Mazid, R. A. Palmer, and A. A. Balchin, Actu Cryst., 1976, B32, 885. ' 02 S. Tamomkol, J. A. Hjortas, and H. Sorum, Actu Cr yst ., 1976, B32,920. lo3 R. E. Lenkinski and J. Reuben, J. Amer. Chem. Soc., 1976,98,3089. S. J. Angyal, C. L. Bodkin, and F. W. Parrisa, Austral. J. Chem., 1975, 28, 1541. 50 Inorganic Chemistry of the Main -Group Elements h .AH (4 (4 Figure 7 Formulae and atomic numbering of ( a ) P-D-fructose, ( b) D-glucarate, ( c ) 2-keto-D- gluconate, and ( d) a-D-galacturonate n Figure 8 The co-ordination shells of calcium in ( a) calcium D-glucarate tetrahydrate and ( b) [Reproduced by permission from ( a ) Bull. Chern. SOC. Japan, 1976,49, 1517, and ( b) Acta calcium 2- ket o-~-ghmnat e tihydrate Cryst., 1976, B32, 8851 by five oxygen atoms of two glucarate moieties [0(1'), 0( 3) , and 0(4), and 0(1) and 0(2), respectively] and three water oxygen atoms; Ca. -0 bond distances vary from 0.239 to 0.257 nm (Figure 8a).loo The nine-co-ordinate Ca2' ion of the gluconate is provided by three carbohydrate residues [0(1), 0(2), and 0(3), twice, and O(1') and 0(6), respectively] and a single water oxygen atom; Ca * - * 0 bond distances vary from 0.233 to 0.273 nm (Figure 8b).'" That of the galacturonate, however, is made up of three galacturonate residues, each contributing a ring oxygen [ 0( 5) ] , a carboxyl oxygen [0(6)], and three oxygen atoms of water The Na* ion of the latter complex is six-co-ordinate, given by three Elements of Group II 51 sets of two hydroxyl oxygen atoms, uiz. O(2) and O(3) of the galacturonate moiety; Ca * * - 0 and Na - - * 0 distances vary from 0.240 to 0.283 and from 0.236 to 0.250 run, respectively.lo2 An analysis of 'Hn.m.r. data for aqueous solutions containing Ca2' (and La3') ions and either D-lyxose or D-ribose has shown that predominantly 1 : 1 cation-sugar complexes are formed.lo3 The resdts also confirm the suggestion that metal complexation occurs with the pyranose in a conformation which has ax-eq-ax arrangement of the three consecutive cis-OH groups. Several glycosides have been synthesized in good yield by altering the anomeric equilibrium, by use of complexing with Ca" or S?+i ~ns.~'~ For example, the acid-catalysed reaction of D-allose with MeOH gives rise to a! -D-furanoside and a-D-pyranoside in the presence of SrCl,, but P-D-pyranoside is the only product in its absence.lo4 Eight-fold co-ordination of Ca2' by oxygen atoms also occurs in CaC12,- (1,4,7,10-tetraoxocyclododecane),8H20105 and Ca(C104)2,(diacetamide),.106 The Ca2+ions of the chloride complex are situated on the crystallographic C2 axis and are co-cordinated to eight oxygen atoms arranged at the apices of a distorted square antiprism. Four oxygens belong to the cyclomer and approximate a square with sides 0.273 and 0.274 nm; the remaining four oxygens belong to water molecules. The Ca. - a 0 distances vary from 0.238 to 0.254 nm.lo5 Two independent Ca2' ions occur in the perchlorate complex; they lie on two-fold axes and are both chelated to the eight oxygen atoms of four diacetamide molecules. The fifth diacetamide molecule is unco-ordinated. The co-ordination geometry around the Ca2+ions is antiprismatic, with an average Ca. - - 0 distances of 0.241 nm. This arrangement of ligand atoms is similar to that found in the CaBr,,(diacetarnide), complex. The crystal structures of Ca(MeC02)(MeCOS)107 and of the analogous Ba(MeCOS)2,3H20108 have been determined. The Ca2' ions are surrounded by seven oxygen atoms (from three acetate moieties and three H,O molecules) situated in a distorted pentagonal-bipyramidal arrangement; Ca * - - 0 distances vary from 0.230 to 0.255 nm. The Ba" ions are nine-co-ordinate, the polyhedra being composed of three thiocarboxyl oxygen atoms, two thiocarboxyl sulphur atoms, and four water oxygen atoms; average Ba - - . O and Ba - - - S distances are 0.28 16 and 0.3293 nm, respectively. These structural arrangements are compared with that of the corresponding Sr complex, Sr(MeC0,)(MeCOS),4H20 in Figure 9; the co-ordination polyhedra are remarkably different, S?' being eight-co- ordinate, and involving both acetate and thioacetate moieties as ligand~.~'~*~'* The thermal decomposition of calcium propionate monohydrate has been studied and the associated enthalpy changes have been determined."' It loses H,O in a single step (A H= 52.97 kJ mol-l). The anhydrous salt undergoes a phase transition (AH = -3.95 kJ mol-l) before it decomposes to CaC03 (AH = -791 kJ mol-I). P. P. North, E. C. Steiner, F. P. van Remoortere, and F. P. Boer, Acta Cryst., 1976, B32, 370. ' 06 J. P. Roux and G. J. Kruger, Acta Cr yst ., 1976, B32, 1171. '0-1 M. M. Borel and M. Ledesert, J. Inorg. Nuclear Chem., 1975, 37, 2334. '09 N. R. Chaudhuri, G. K. Pathak, and S. Mitra, Indian J. Chem., 1975,13, 689. M. M. Borel and M. Ledesert, Acta Cryst., 1976, B32, 2388. 52 Inorganic Chemistry of the Main-Group Elements 1' 1' (4 (b) (4 Figure 9 Environment of the alkaline-earth-metal cations in ( a) Ca(MeC0,) (Reproduced by permission from Acta Cryst., 1976, B32, 2388) MeCOS),3H20, ( b) Sr(MeC02)(MeCOS),4H20, and ( c ) Ba(MeCOS),,3H20 Thermodynamic characteristics of Ca-EDTA complex formation in aqueous solution have been derived at 288, 298, and 308 K and at ionic strengths of 0.3, 0.5, and 1.0 (KNO,).l'o Conductivity and i.r. data suggest that CaH,EDTA is an acid salt of EDTA, and that the concentration of the ionic complex (if it exists) is negligible. l1 Strontium and Barium Derivathes.-Crystals of strontium violurate tetrahydrate are monoclinic, of space group P2, / a, with a = 2.217, b = 0.498, c = 1.447 nm, p = 1 O 4 O . ' l 2 The molecular structure (Figure 10) is such that the Sr" ions are eight- co -ordinate, the environment being composed of seven oxygen atoms {four w Figure 10 Partial molecular structure of strontium uiolurcte tetrahydrate, illustrating the (Reproduced by permission from Acta Cryst., 1976, B32, 364) co-ordination of the Sr2+ ion 'lo V. P. Vasil'ev and A. K. Belonogova, Russ. J. Inorg. Chem., 1976, 21, 31. "' G. A. Rykova and E. B. Shternina, Russ. J. Inorg. Chern., 1975, 20, 1610. "' M. Hamelin, Acta Cryst., 1976, B32, 364. Elements of Group II 53 two ketonic [0(1) and 0 ( 5 ) ] , and one oximino [0(4)J) and one oximino nitrogen atom. Pertinent bond distances/nm and angles/" are shown in the Figure.", The kinetics of crystallization and of dissolution of S~(OX),H,O~~~ and of Ba(0x),2H,0"~ have been studied at 298 K, by following changes in the ,con- ductivity of supersaturated and subsaturated aqueous solutions. Single crystals of Ba(NH,), have been prepared by the prolonged reaction of Ba metal with liquid NH3;l15 there are two crystallographically independent Ba2' ions, with irregular eight- and seven-fold co-ordination. The kinetics of the thermal decomposition (608-643 K) of barium formate have been ascertained.' l6 Decomposition occurs via two major modes [equations (6) and (7)], with small amounts of HCHO, elemental C, and 0, also being formed. ,BaCO, + CO + H, bB aO + CO, f CO + H, Ba(HCO,), '13 G. L. Gardner and G. H. Nancollas, J. Znorg. Nuclear Chem., 1976, 38, 523. '14 S. T. Liu and G. H. Nancollas, J. Znorg. Nuclear Chem., 1976, 38, 515. 11' H. Jacobs and C. Hadenfeidt, 2. anorg. Chem., 1975, 418, 132. '16 N. D. Sinnarkar and M. N. Ray, Indian J. Chem., 1975, 13, 962. 3 Elements of Group 111 BY G. DAVIDSON 1 Boron Boranes.-M.O. calculations on the species BH5, that has been predicted as a metastable intermediate in the hydrolysis of B&-, using PRDDO and STO-3G minimum basis sets, or 4-31G and double plus polarization extended sets, were unable to confirm these predictions.' A Lewis orbital model has been used to produce useful estimates of geometries, and to describe some aspects of rearrangement dynamics for B,H, and CH,BH,. Electronic repulsions roughly parallel total energy, therefore giving some theoret- ical support for the VSEPR B n.m.r. spectra at various temperatures show that the first step in the reaction of BR,(R=Et or Pi ) with BH, in THF involves the formation of unsymmetrical species R2BH2BH2. Subsequent steps depend upon the BR,/BH, ratio, and on the nature of R., Coupling constants have been determined for B4HI0 [B( 1)-B(3)], CB,H, [B(l)- B(4)], and several other compounds. J (llB-H) and J('lB-''B) values were used to obtain s,-orbital populations, which were in good agreement with those calcu- lated by PRDDO methods. J("B-H) is a sensitive measure of bond distance, and this was used to give an estimate (1.30A) for the length of B-H for the unique bridge hydrogen in B,H,1.4 A new route to pentaborane(9), free from pentaborane( 11) by-products, in- volves the preparation of a halogenated octahydroborate ariion [reaction (l)]. 11 Bu;N(B,H,) + HBr __* BuzN(B,H,Br) +H, (1) Thermal decomposition of this bromo-borane produces B5Hg (36.8% from the original B,H, salt), the only by-products being B2Hs and a trace of B ~H ~o . ~ PMe, reacts with B6H10 in THF or a hydrocarbon solvent, to form crystalline B6H10(PMe3)2, the topological structure of which is shown in (1). This does not have a pentagonal-bipyramidal structure, but one derived from a fragment of the I. M. Pepperberg, T. A. Halgren, and W. N. Lipscomb, J. Amer. Chem. Soc., 1976, 98, 3442. C. Trindle and L. C. Weiss, J. Phys. Chem., 1975, 79, 2435. B. Wrackmeyer, J. Organometallic Chem., 1976, 117, 313. T. Onak, J. B. Leach, S. Anderson, M. J. Frisch, and D. Marynick, J. Magn. Resonance, 1976, 23, 237. G. E. Ryschkewitsch and V. H. Miller, J. Amer. Chem. Soc., 1975, 97, 6258. 54 Elements of Group III 55 equatorial belt of an icosahedron. Electron counts reveal that it is a derivative of the hypho-boranes, containing (2n + 8) skeletal electrom6 Low-temperature 'H and line-narrowed "B n.m.r. spectra have been reported for B8H1, and i-B'H15. An analysis of the data suggests that the B8Hl4 contains four 'unique terminals' and two bridging hydrogens around the open face of the B5 cage. The i-B9H15 molecule has 6 asymmetric bridging hydrogens around the open face of a B, cage of C,, ~ymmetry.~ New decaboranyl ethers have been prepared as shown in reactions ( 2) and (3). NaB,,H,, or Na,B,,H,, +SnCl, in Et20 + 6-EtOB,,H1, (2) NaB,,H,, or Na2B,,H12 +Me,SiX in ethers -+ 6-Me3SiOB,,H,, (3) (X = ClorBr) In addition, 6-PhB10H13, hitherto poorly characterized, is formed in the pyrolysis of Ph2SnB,,H,2.8 B1&9 may be prepared quite conveniently by the route shown in reactions (4) and ( 5) . The B13H19reacts smoothly with KH to give the stable salt KB13H18, KB6H,Br +$B,H6+ KB,H,,Br (4) KB,H,,Br + B&f,(,+ B,,H,, + H, +KBr ( 5) which regenerates the parent borane on acidification. The molecular structure of B13H19 was determined from single-crystal X-ray measurements. It is built up from an n-B9H15 cage, by sharing two B atoms with a B&,O unit.' Borane Anions and Metallo-derivatives.-The derivatives (&N)BH4 have been prepared conveniently and in good yield (R=Me, 71%; R=Et, 81.5%) from KBH, by ion exchange on cationic resins." A similar general method for the preparation of tetra-alkylammonium tetrahydroborates NR,BH4 has also been proposed, where FL, = Me,, Bd, BuZMe, Bu';Et, (c6Hl3)&, (C6H13),Bun, or (C12H2&Et. This involves the treat- ment of NRJ in aqueous EtOH at 0°C with AV-17 anion-exchange resin in the BH, form. l1 M. Mangion, R. K. Hertz, M. L. Denniston, J. R. Long, W. R. Clayton, and S. G. Shore, J. Amer. Chem. Soc., 1976, 98, 449. D. C. Moody and R. SchaeiTer, Inorg. Chem., 1976, 15, 233. R. E. Loffredo, L. F. Drullinger, J. A. Slater, C. A. Turner, and A. D. Norman, Inorg. Chem., 1976, 15, 478. J. C. Huffman, D. C. Moody, and R. Schaeffer, Inorg. Chem., 1976, 15, 227. G. Guillevic, F. Maillot, H. Mongeot, J. Dazord, and J. Cueilleron, Bull. Soc. chim. France, 1976, 1099. K. N. Semenenko, 0. V. Kravchenko, and S. P. Shilkin, Russ. J. Inorg. Chem., 1975, 20, 1293. 56 Inorganic Chemistry of the Main-Group Elements Alkali-metal tetrahydroborates reduce Cr203 at temperatures in excess of 250°C (for LiBH,) to 430°C (for CsBH4), in the same manner as shown in equation (6).12 2Cr,O, +3KBH, + 3KB0, +4Cr +6H2 ( 6) Marynick has reviewed the structural possibilities for Be(BH,),, especially the question of C,, versus D3d symmetry. The results of M.O. calculations indicated that the latter was more likely, but the predicated differences in energy were very small. It was suggested that more theoretical and experimental work is needed on. the pr0b1em.l~This is borne out also by a re-consideration of the gas-phase electron-diffraction data on 'BeB,H,'. These showed that at least two different molecular species were present, in variable amounts in different samples. I t is therefore not possible, at present, to obtain molecular structures from such data.', Measurements of vapour pressure suggest that methylberyllium borohydride is dimeric. 1.r. and Raman spectra of the solid are also consistent with the presence of dimers (2), of C,, symmetry. Quite complete vibrational spectroscopic assign- ments have been proposed for this.15 1.r. and Raman spectra have also been reported and assigned for C,H,BeBH, and C,H,BeBD,. The hydrogen bridge structure is definitely (3), and, in contrast to Be(BH,),, this is found in the gaseous, liquid, and solid states. The BeH,B plane and the C, molecular symmetry plane are c~incident.'~ The vibrational spectrum of Zr(BH,), has been re-interpreted in terms of T rather than Td symmetry. Group frequencies for the unit (4) were confirmed in the region 500-650 cr"'.'' Numbers of Ru" and RU"' complexes containing BH, and/or BH,CN- ligands have been prepared, e.g. RuH(BH4)(PPh3),. These are the first Rurl complexes of this type. N.m.r. assignments show that several of the species prepared are present as mixtures of geometrical isomers.'* L. S. Alekseeva, N. N. Mal'tseva, Z. K. Sterlyadkina, and V. I. Mikheeva, Russ. J. Inorg. Chem., 1975, 20, 1296. 12 l 3 D. S. Marynick, J. Chem. Phys., 1976, 64, 3080. l4 K. Brendhaugen, A. Haaland, and D. P. Novak, Acru Chem. Scund. (A), 1975, 29,801. l5 L. J. Allamandola and J. W. Nibler, J. Amer. Chem. Soc., 1976, 98, 2096. l6 D. A. Coe, J. W. Nibler, T. H. Cook, D. Drew, and G. L. Morgan, J. Chem. Phys., 1975,63,4842. '' B. D. James, B. E. Smith, and H.'F. Shurvell, J. Mol. Strucrure, 1976, 33, 91. D. G. Holah, A. N. Hughes, and B. C. Hui, Canad. J. Chem., 1976, 54, 320. Elements of Group III 57 Exactly analogous types of complexes, containing Rh', Rh", and RhI'I, have been reported. The Rh' species are all very unstable, but Rh"H(BH4)(o-to1ylsP) and Rh1"H,(BH3CN)(PPh3), are much more stable.'' Complexes IrH2(BH4)L, where L is a bulky tertiary phosphine, have been prepared. They are the first examples of metal-hydroborate complexes in which the BH, ligand is non-fluxional. Thus, the structure is ( 5) , and 'H n.m.r. signals were seen separately for the bridge and terminal hydrogen atoms.20 The i.r. and Raman spectra of (q5-C5H5)2Ln(BH4), THF, where Ln = Sm, Er, or Yb, show that the co-ordination mode of the BH, ligand is sensitive to the ionic radius of the metal. When Ln = Sm, it is terdentate, but when Ln = Yb it is clearly bidentate. Removal of the THF, for the Ln=Y b and Er complexes, gives ( q5-C5H5)2Ln(BH,), whose vibrational spectra are indicative of a polymeric structure, with bridging BH, units.2' Ab initio quantum-mechanical calculations have been performed on BH5 and B2H;. In the SCF approximation, BH5 is not stable with respect to BH3+ H2, although when electron correlation is included it has a binding energy of -2 kcal mol-', in a C, geometry. Previous SCF results were confirmed for B2H7, while the inclusion of correlation gives very good agreement with the ex- perimental binding energy, with respect to BH3 + BK-. A symmetric structure with one linear B-H-B bond was found to be preferred.22 Several new complexes containing B/Co clusters have been prepared and characterized, e.g. (q5-C5H,),Co3B3H5 (6). N.m.r. and mass spectral data were reported. The compound shown is the first to be characterized which contains as many metal as boron atoms, while Cp,Co,B,H, is the first known to contain four metal atoms in the cluster. Cp,Co,B,H, contains an 'isolated' boron atom, i.e. it is bound only to Co, and not to B.23 B3Hi undergoes a one-electron oxidation, at a Pt or Au anode, in MeCN or DMF(=S) solutions, to give species B3H,,S. Protonation in MeCN gives an identical product, but in DMF the B3 array is broken down on pr~tonati on.~~ Be(B3HS)2 possesses a solid-state structure in which two terdentate B3H8 l9 D. G. Holah, A. N. Hughes, and B. C. Hui, Canad. J. Chem., 1975, 53, 3669. 2o H. D. Empsall, E. Mentzer, and B. L. Shaw, J.C.S. Chem. Comm., 1975, 861. 21 T. J. Marks and G. W. Grynkewich, Znorg. Chem., 1976, 15, 1302. 22 C. Hoheisel and W. Kutzelnigg, J. Arner. Chem. Suc., 1975, 97, 6970. 23 V. R. Miller and R. N. Grimes, J. Amer. Chem. Soc., 1976, 98, 1600. 24 P. J. Dolan, J. H. Kindsvater, and D. G. Peters, Znorg. Chem., 1976, 15, 2170. 58 Inorganic Chemistry of the Mai n-Group Elements ligands are bound to a central Be, via two Be-H-B bridge units from adjacent B atoms of the B,H;. The overall molecular symmetry is C,, and the Be atom has approximately tetrahedral co-ordination. The B,H, units are geometrically essen- tially identical with free B,Hi ions. This compound is the first known example of two B,H; ligands attached to the same Variable-temperature 'H n.m.r. spectra of L,CuB,H, derivatives have been recorded for L=P(OPh)3, AsPh,, and PPh,. Attempts to correlate rates of B3H8 rearrangements with the electronic properties were not entirely successful.26 Be(BH,), reacts with 1-chloropentaborane(9) to give insertion of Be into the borane cage. The resultant species is 2-tetrahydroborato-2-berylla-nido-hexa- borane(l1). The structure (Figure 1) was confirmed by X-ray Figure 1 Static molecular structure of B,H,,BeBH, (Reproduced fromJ.C.S. Chern. Cornm., 1976, 482) Methylmagnesium halides and Mg, Zn, and Cd dimethyls deprotonate hexa- borane( 10) to give several new metalloboranes; these are M(THF),(B,H,),, where M=Mg or Zn, and Cd(B,H,),. The 'H n.m.r. spectra of all of these show that they are stereochemically non-rigid, with low-temperature spectra characteristic of insertion of metal into the basal B-B anion bond. The crystal structure of Mg(mq2(B6H9), shows that each anion is co-ordinated to Mg through one of its two non-adjacent basal B-B bonds. Mg-B distances of 2.38(1) and 2.48(1) A were obtained, with r(Mg-0) = 2.019(5) A.28 (7) A number of diazonium derivatives of B,,H?; have been prepared by the thermal decomposition of protonated arylazo-derivatives, e.g. (7) + 1-B,,H,N; + 1, 3, 5-C6H, Br, +base A variety of polyhedral Blo species can be prepared by this route.29 25 J. C. Calabrese, D. F. Gaines, S. J. Hildebrandt, and J. H. Morris, J. Amer. Chem. Soc., 1976, 98, 26 C. H. Bushweller, H. Beall, and W. J. Dewkett, Inorg. Chem., 1976, 15, 1739. 27 D. F. Gaines and J. L. Walsh, J.C.S. Chem. Cornm., 1976, 482. 5489. D. L. Denton, W. R. Clayton, M. Mangion, S. G. Shore, and E. A. Meyers, lnorg. Chem., 1976,15, 541. 28 29 R. N. Leyden and W. F. Hawthorne, lnorg. Chem., 1975, 14, 2444. Elements of Group III 59 Fluxional behaviour in the n.m.r. spectrum of solutions of [(P~,P),CU]~B~&I~, does not necessarily imply the existence of Cu-H-B interactions (previously postulated for this species in the solid state), but it is a common phenomenon in complexes where such interactions do The mixed halides M2B12H12,MX ( M=K, Rb, or Cs; X=C1, Br, or I) are isolable from mixtures of the constituent species.31 Carba- and Other Non-metal Hetero-boranes.-Treatment of selected products of the hydroboronation of buta-1,3-diene with KH leads to H- addition, giving singly hydrogen-bridged anions, e.g. p-hydro-1,2-dihydro-l,2: 1,2-bis(tetra- methylene)diborate, B,(C,H,),H,. The crystal structure of this anion (Figure 2) shows clearly the presence of a transannular hydrogen bridge.32 Figure 2 Structure of B,(C,H,),H; (Reproduced by permission from J. Arner. Chern. Soc., 1975, 97, 6063) Chlorine, under reduced temperature and in an inert solvent, reacts with closo- 1,5-C2B3H5 to produce 2-C1-1,5-GB3H4. In a hotlcold reactor, BMe, and 1,5- C,B3H5 form a mixture of B-mono-, -di-, and &-methyl derivatives of the closo-carbaborane. The dimer 2,2’-C2B3H4-C2B3H4 and B-methyl derivatives are also The reactivities of some small closo -carbaboranes towards water and MeOH have been compared. The reactivities fall in the sequence 1,5-C2B3H5 > 2,4- C,B5H, > 1 ,6-C2B4&. The smallest species forms initially the triborapentane 30 G. G. Outterson, V. T. Brice, and S. G. Shore, Inorg. Chem., 1976, 15, 1456. 31 N. T. Kuznetsov, G. S. Klimchuk, and 0. A. Kanaeva, Russ. 3. Inorg. Chem., 1975, 20, 1416. 32 D. J. Saturnino, M. Yamauchi, W. R. Clayton, R. W. Nelson, and S. G. Shore, J. Arner. Chcrn. Soc., 33 R. C. Dobbie, E. W. Distefano, M. Black, and T. Onak, J. Organometallic Chem., 1976,114,233. 1975, 97, 6063. 60 Inorganic Chemistry of the Main-Group Elements (RO),BCH,B(OR)CH,B(OR),, where R = H or Me, but the others give cleavage The donors Me,L, where L = P or N, react with the small cbso-carbaboranes in the reactivity sequence 1,5-C2B3HS > 1,6-C2B4H6 > 2,4-CzBSH7. The largest cage gives no reaction with Me3L, but Me,NH cleaves it, to produce Me,NH,BH3 and an involatile polymer that is thought to be (S), where X = H and/or Me,NBH.35 A number of penta-alkyl-1,5-dicarba-closo-pentaboranes(5) (9; R1 = Me, R2=Me, Et, or Pr) have been produced from reactions between the dialkyl(1- alkyny1)boranes R: BMRZ and the tetra-alkyldiboranes (RiBH),. Tris(diethy1- boryl)methane, (Et,B),CH, has also been reported, and this gives, on treatment with triethylaluminium, both 2,3,4-triethyl-1,5-dicarba-cZoso-pentaborane(5) (10) and the adamantane derivative (l l).36 CH2RL I (9) (10) (11) MeCl reacts with 2,4-c&BSH7 in the presence of catalytic amounts of AlC13 to give B -methyl derivatives. Positional preference for substitution was found, in the order 5,6 > 1,7 > 3. This is consistent with an electrophilic mechanism for sub- ~ti tuti on.~~ The microwave spectrum of 1,7-dicarba-cZoso-octaborane(8) has been studied. An assignment of the rotational spectra for nine isotopic species was achieved. The C,B, skeleton has slightly distorted D,, geometry in the gas phase (see Figure 3). AU of the bond distances were A general photochemical method has been reported for the preparation of B-B coupled boranes and carbaboranes. This is Hg-sensitized, using 253.7 nm 34 R. C. Dobbie, E. Wan, and T. Onak, J.C.S. Dalton, 1975, 2603. 35 L. Lew, G. Haran, R. C. Dobbie, M. Black, and T. Onak, J. Organometallic Chem., 1976,113, 123. 36 R. Koster, H. 4. Horstschafer, P. Binger, and P. K. Mattschei, Annulen, 1975, 1339. J. F. Ditter, E. B. Klusrnann, R. E. Williams, and T. Onak, Inorg. Chem., 1976, 15, 1063. H. N. Rogers, K.-K. Lau, and R. A. Beaudet, Inorg. Chem., 1976, 15, 1775. 37 38 Elements of Group IIl 61 Figure 3 Molecular structure of C,B,H, (Reproduced by permission from Inorg. Chew., 1976, 15, 1775) radiation, e.g. reaction (7). Yields were quite good, and the products were generally free from undesirable by-product^.^^ The microwave spectra of six isotopic variants of 1,6-C2B,H, were used to obtain the following bond distances: B(8)-B(9) 1.712, B(5)-B(9) 1.995, B(3)-B(4) 1.976, B(7)-B(9) 1.784, B(2)-B(3) 1.805A. The molecular dipole is 2.14* 0.17 D.40 The recently reported compound 10-aza-7,s-dicarba-nido -undecaborane( 1 l), 10-PhCH2-10-N-7,8-C2B,Hlo, has had its formulation as a nido-compound con- firmed by an X-ray structural determi nati ~n.~~ The reduction of 6-Me,N-6-CB,Hll yields 6-CB9Hy2, which can be degraded hydrolytically to 4-CB,Hl, (12), the first monocarbaborane belonging to the arac hno -series.42 Treatment of 1,7-Me,-1,7-&BloHlo with alcoholic base leads to degradative J. S. Plotkin and L. G. Sneddon, J.C.S. Chem. Comm., 1976, 95. 39 40 K.-K. Lau and R. A. Beaudet, Inorg. Chem., 1976, 15, 1059. 41 J. PleHek, S. Heiminek, J. Huffman, P. Ragatz, and R. Schaeffer, J.C.S. Chem. Comm., 1975,935. 42 B. Stibr, K. BaSe, S. Heimainek, and J. PleSek, J.C.S. Chem. Comm., 1976, 150. 62 Inorganic Chemistry of the Main-Group Elements substitution, and the production of 7,9-Me2-7,9-C,B,H,(OR), where R is Me, Et, or PI!, and the alkoxy-group is in the 3-positi0n.~~ New examples of carbaboranes with nitrogen or sulphur atoms incorporated into the polyhedral skeleton have been reported recently. The nitrogen com- pounds, the 8- and 4-aza-1,2-dicarba-nido-undecaboranes C2BsNHll and C2B8NH13, respectively, result, together with other compounds, when aqueous NaNOz reacts with the alkali-metal 1,2-dicarbaundecaboranes M’ C2B9HT2. The sulphur compound is 8-thia-1,2-dicarba-nido-undecaborane, C2BsSH10, which is also formed by a similar reaction with aqueous bi s~dphi te.~~ The 1,2- and 1,7-dicarbaundecaborane dianions C,B,H:,, formed by proton abstraction from the corresponding anions GB,H,, undergo alkylation with alkyl halides. Although the alkyl group is thought to occupy initially a bridge position, it exchanges rapidly with the terminal hydrogen at B(4), and then undergoes slow rearrangement to give the 6-alkyl deri~ative.~’ In an attempt to rationalize the radiation-induced polymerization of substituted carbaboranes, INDO calculations have been carried out on a series of o-carba- boranes containing organo-substituents. The calculated values of the dipole moments were too large, but they indicated that the substituted carbaboranes pump electron density into the cage.46 The crystal structure of tribromo- rn -carbaborane shows that the third bromine atom is attached to B(12) or B(3.4’ Gas-phase electron-diffraction results have been used to obtain molecular structural parameters for CC‘-di-iodo-p-carbaborane, l,12-C212BloHlo. The intra-cage geometry is hardly altered by the replacement of H by I.48 The 0- and rn-carbaboranes are mercurated by Hg(CF,C02)2 at the 9-position of the icosahedral frame~ork.~’ Reduction of C-nitroso-o - and - rn -carbaboranes provides a ready route to the C-amino-derivatives, which are less well known than the B -amino-analogues. The products are weak bases, and they give unstable hydrochlorides only. On heating with formic acid, N-formyl derivatives are readily formed, while N-acetyl compounds are made by the action of either acetic anhydride or acetyl chloride.” Conditions have been reported for the silylation of the lithium derivatives of o- and m -carbaboranes with alkoxychlorosilanes, to produce good yields of the alkoxysilyl deri vati ~es.~~ The reaction of methyl-o-caibaboranyl-lithium with PCl, gives substitution of two C1 atoms into the carbaboranyl fragment. Tris(methy1-o-carba- borany1)phosphine results when this product is treated with further Me-o- CB,,H,oCLi.52 43 W. R. Pretzer, D. A. Thompson, and R. W. Rudolph, Inorg. Chem., 1975, 14, 2571. V. A. Brattsev, S. P. Knyazev, G. N. Danilova, and V. I. Stanko, J. Gen. Chem. (U.S.S.R.), 1975,45, 1364. J. H. Kindsvater, R. M. Metzger, and T. J. Klingen, J. Inorg. Nuclear Chem., 1976, 38, 1093. A. Almenningen, 0. V. Dorofeeva, V. S. Mastryukov, and L. V. Volkov, Acta Chem. Scand. (A), 1976, 30, 307. V. I. Bregadze, V. Ts. Kampel, and N. N. Godovikov, J. Organometallic Chem., 1976, 112, 249. L. I. Zakharkhin and G. G. Zhigareva, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1268. 44 ” V. A. Brattsev, S. P. Knyazev, and V. I. Stanko, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1173. ‘’ A. A. Sayler and H. Beall, Canad. J. Chem., 1976, 54, 1771. 46 48 49 51 V. V. Korol’ko, V. I. Lebedeva, and A. V. Passet, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1036. ’’ V. I. Bregadze, N. N. Godovikov, A. N. Degtyarev, and M. I. Kabachnik, J. Organometallic Chem. 1976,112, C25. Elements of Group III 63 y-Radiolysis of pure solid o-carbaborane at 31 "C gives H2, CH4, GH,, and the adduct dimer and trimer of o-carbaborane and icosaborane(l6), BZ0Hl6, via a chain mechanism.53 Some 13C and "B shielding values have been found for a large number of icosahedral heteroatom boranes. Shielding effects were found that were due to variations in (i) directly bonded exopolyhedral groups, (ii) ortho-cage groups, (iii) metu -cage groups, and (iv) para-cage Sodium nitrate reacts with B1OH14 in THF to give a species which, on acidification, produces 4-NB8HI3; the first uncharged azaborane of this type. The - _ structure (Figure 4) is derived from an iso-B,H,, cage, with the ninth B replaced by N." Figore 4 Molecular (Reproduced from b structure of 4-NB,H1, J.C.S. Chem. Comm., 1975, 934) Decaborane, when treated with RPC12 (R= Me, Et, Pf, or Ph) and excess NaOH, forms 7-BloHI1PR-, which can be protonated to give 7-BloH12PR. Pure Me4N" salts of the anion result from dissolving the neutral compound in dilute NH3, and precipitating with Me,NCl. Treatment of 7-B10H12PR with CoCl,, 53 M. A. Mathur and T. J. Klingen, J. Inorg. Nuclear Chem., 1976, 38, 1597. 54 L. J. Todd, A. R. Siedle, G. M. Bodner, S. B. Kahl, and J. P. Hickey, J. Magn. Resonance, 1976,23, 301. '' K. BaSe, J. PleBek, S. Heimlnek, J. Huffman, P. Ragatz, and R. Schaeffer, J.C.S. Chem. Comm., 1975, 934. 64 Inorganic Chemistry of the Main-Group Elements CsH6, and excess KOH in anhydrous EtOH produces (q5-C,H,)Co(q-7- BloHloPR), for which structure (13) has been proposed, and [(q5-C5H,)Co(q-7- B 10~10~)I -.56 Studies on the halogenation of 1-SB9H9 suggest that cage rearrangement plays a role in the ultimate stereochemistry of the A number of reactions of thiaboranes have been reported, and their products characterized. It appears that the structures of the 12-, 11-, lo-, and 9-vertex thiaboranes are closely related to those found for boranes and carbaboranes with the same number of framework electrons. A number of the resultant complexes were described for the first time.58 Pyrolysis of nido-thiaboranes 6-SB9Hll and 7-SBl,H,, gives closo-thiaboranes and a variety of isomeric polydeltahedral thiaboranes, linked via a B-B two- centre bond, and constructed from the basic units shown in Figure 5. The B-B link always involves vertices of order 5.59 Figure 5 Proposed structural units and numbering conventions for thiaboranes. Each delta- hedral vertex represents BH, CH, s, or B, depending upon the molecule under consideration. (Reproduced by permission from Inorg. Chem., 1976, 15, 1779) 56 J. L. Little, Inorg. Chem., 1976, 15, 114. '' W. L. Smith, B. J. Meneghelli, N. McClure, and R. W. Rudolph, J. Amer. Chern. Soc., 1976,98,624. 59 W. R. Pretzer and R. W. Rudolph, Inorg. Chem., 1976, 15, 1779. W. R. Pretzer and R. W. Rudolph, J. Amer. Chern. Soc., 1976, 98, 1441. Elements of Group III 65 2,2'-Bis-l-thia-cZoso-decaborane(8), 2,2'-( 1-BgH8S)2, forms monoclinic crystals, of space group P2,ln. The molecular structure is shown in Figure 6. The B-B bond length is 1.678(5)A, linking two bicapped square antiprisms B9H8S, in which the S is axial. The equatorial belt of four B atoms closest to the S contains the B through which the BgH8S units are connected. The B-S bond length is 1.923(3); the other B-B lengths are between 1.940(3) and 1.689(4)&60 5P 1.124(253 Figure 6 Molecular structure of 2,2'-( 1-B9H,S), (Reproduced by permission from Inorg. Chem., 1975, 14, 2459) Metallo-heteroboranes.-Single-crystal X-ray studies of the dicobalt metallo- carbaborane 2-Me-1,7,2,4-(q5-C5H5)2C02&B3H4 confirmed the 'triple-decker sandwich' structure (Figure 7). The central planar ring, C2B3H2-, is isoelectronic with C5H;.6' B and 'H pulse F.T. n.m.r. spectra of the triple-decker sandwich metallo- carbaboranes 1,7,2,3- and 1,7,2,4-(q -C5H5)2C02C2B3H5 suggest that the latter contains a highly delocalized metallocene-type central ring. The former seems to contain strong, localized w-interactions between the metal atoms and an ethylenic double bond in the central ring.62 A number of new iron-hydrogen and iron-cobalt metallocarbaboranes have been prepared. Thus FeCl, reacts, below - 30 "C, with Na" Me2C2B,HT to give (CC'-Me,C,B4H,),FenH,. The two H atoms are bonded to the Fe, and probably occupy bridging sites over triangular faces of the polyhedra. A by-product of one series of reactions based on this species is the new, air-stable Me4C4B8H8, in at least two isomeric forms: an open structure with two edge-linked Me2C2B4H4 11 6o W. R. Pretzer, T. K. Hilty, and R. W. Rudolph, Inorg. Chem., 1975, 14, 2459. " W. T. Robinson and R. N. Grimes, Inorg. Chem., 1975, 14, 3056. 62 R. Weiss and R. N. Grimes, J. Organornetallic Chem., 1976, 113, 29. 66 Inorganic Chemistry of the Main-Group Elements C13 C13 Col 63 C72 c7 2 C71 Figure 7 Molecular structure of 2-Me-1,7,2,4-(q5-C,H,)2C02C2B3H4 (Reproduced by permission from Inorg. Chern., 1975, 14, 3056) units, and a distorted icosahedron, which exhibits fluxional n.m.r. behaviour at 40 0C.63 Na'Me,C,B,H; reacts with CoCl, at 25°C to form a red, neutral cornrno- metallocarbaborane (CC'-Me,~B,H,),Co"'H. As in the previous Fe complex, the H atom appears to be face-bonded to a triangular face of the polyhedral surface. The treatment of this complex with aqueous acid produces a nido,closo- species (CC-Me,C,B,H,)CoH( CC'-Me,C,B,H,). A number of other cobalta- boranes were produced from the latter by a variety of reaction^.^, [ 1,2,3-(q5-C5H,)CoMe2C2B4H4] reacts with Fe(CO)s to give the complex [{(CO)3Fe}2(q5-C,H,)CoMe2C2B,H4]. This is a 9-vertex polyhedral cage system with the highest reported ratio of metal to non-metal cage atoms among known metallocarbaboranes. It is also the first example of a mixed-metal trimetallocarba- borane, and its proposed structure is shown in Figure 8.65 Several isomeric forms of the first trimetallocarbaborane containing Ni have been isolated and characterized. They have the formula (CPN~)~CB~H,R, where R = H or Me. They are mixed-valence species, Nil"-Nir"-Ni", with substantial charge transfer. The crystal structure of one isomer was determined, showing a novel nido -geometry, with a monocapped square antiprismatic skeleton (Figure 9)? '' W. M. Maxwell, V. R. Miller, and R. N. Grimes, Inorg. Chem., 1976, 15, 1343. 64 W. M. Maxwell, V. R. Miller, and R. N. Grimes, J. Amer. Chem. SOC., 1976, 98, 4818. 65 W. M. Maxwell and R. N. Grimes, J.C.S. Chem. Comm., 1975, 943. 66 C. G. Salentine, C. E. Strouse, and M. F. Hawthorne, Inorg. Chem., 1976, 15, 1832. Elements of Group I11 67 0 Figure 8 Proposed molecular smcture of [{(CO),Fe}2(~5-C,H,)CoMe2C2B,H,] (Reproduced from J.C.S. Chern. Cornrn., 1975, 943) groups and hydrogen The reaction of closo-2,4-C2B5H, with Pt(styrene)(PEt,), leads to the forma- tion of clos0-2,3-[(Et,P)~],-1,2,3,6-CPt~CB,H,. The structure of this is shown in Figure 10; the Pt,GB5 cage is a highly distorted, tricapped [2C and B(8)] trigonal prism. The Pt(2)-Pt(3) distance is 3.051(4)& i.e. there is only a weak interac- tion, but this is nevertheless the first proven example of a closed nine-atom carbaborane cage containing two metal atoms.67 The same paper reported the 67 G. K. Barker, M. Green, J. L. Spencer, F. G. A. Stone, B. F. Taylor, and A. J. Welch, J.C.S. Chem. Comm., 1975, 804. 68 Inorganic Chemistry of the Main-Group Elements W P(21') Figure 10 Molecular structure of closo-2,3-[(Et,P),],-1,2,3,6-CPt2CB5H7; phosphinoethyl (Reproduced fromJ.C.S. Chem. Comm., 1975,804) groups are omitted formation of nido-~(4,8)-[(Me,P)2Pt]-8,8-[(Me,P)2]-7,8,10-CPtCB,Hlo by the reaction of 1,6-C2B,Hl, with Pt(l,5-C,Hl,)(PMe,),. Single-crystal X-ray structural determinations have been carried out on 1,8,5,6- and 1,7,5 ,6-(q5-C5H,),Co,C,B,H,. The molecular structures are built up from 9-vertex, tricapped trigonal prisms.68 Four isomers of the mixed-metal trimetallocarbaborane Cp,CoNi(CB,H,) have been characterized. These undergo novel thermal polyhedral rearrangements, in which metal atoms migrate to adjacent polyhedral vertices and remain there. These illustrate the first example of a thermally stable metal-metal interaction in a metallocarbaborane (see Figure 11). A general rearrangement scheme was de- veloped for 10-vertex polyhedra and used in analysing polyhedral rearrange- ments. While attempting to synthesize a higher homologue of the mixed metal species, (q-CloH8)C~"'(CBloH1 was isolated, being the first metallocarba- borane to be obtained that contains a neutral arene ligand attached to the A crystal structure analysis of Pt(Me2C2B7H7)(PEt3)2 shows that the polyhedral geometry is almost that of a bicapped (by B and C) square antiprism. The metal atom is in a CBBPt face, adjacent to the B cap. The Pt-C distance is 2.83 A, i.e. there is no interaction between them, and thus the molecule has a nido- structure (14), with an open face. The expected closo-structure is not preferred, because of the preference of the Pt atom for square-planar co-ordination and the low polyhedral connectivity of C.70 Cyclo-octa-1,5-dienebis(triethylphosphine)nickel reacts with 5,9-Me2-5,9- C2B7Hll, giving Ni(C,B,H,Me,)(PEt,),. Analogous reactions have been reported for a number of other Ni and Pt complexes, and for the parent arachno-carba- borane 5,9-C2B7Hl,. In the nickel complex mentioned, the metal atom is joined to a B2C system in a 1,2,3-q-bonding mode.71 68 R. N. Grimes, A. Zalkin, and W. T. Robinson, Inorg. Chem., 1976, 15, 2274. 69 C. G. Salentine and M. F. Hawthorne, J. Amer. Chem. SOC., 1975, 97, 6382. 70 A. J. Welch, J.C.S. Dalton, 1975, 2270. 71 M. Green, J. A. K. Howard, J. L. Spencer, and F. G. A. Stone, J.C.S. Dalton, 1975, 2274. Elements of Group III 69 I Y 4w 95% m Ip Figure 11 Proposed rearrangement scheme for the isomers of Cp,CoNi(CB,H,); a cyclo- (Reproduced by permission from J. Amer. Chem. SOC., 1975, 97, 6382) pentadienyl group has been omitted from N B /Pt\B ‘ C’ A number of oxidative addition reactions leading to the formation of new 10- and 1 1-vertex hydridometallocarbaboranes have been described, e. g. NaC2B,H12 and MCl(PAr,),, where M=Rh or Ir, or RuHCl(PPh,), give the doso-species 6,6-(PAr3),-6-H-6,2,3-MC2B7Hg and 6,6-(PPh,),-6,2,3-RuC2B7Hg, respectively. IrCl(PPh,),, with NaC2B,Hl,, produces l,1-(PPh3)2-1-H-1,2,4-Ir~B8Hlo.72 The crystal structures of 6,8-dimethyl-l,l-bis(trimethylphosphine)- and 1,l- bis(tr~ethylphosphine)-6,8-dicarba-l-platinaoctaborane (Figure 12) have been determined. They have C2 molecular symmetry, and cZoso -polyhedral cages closely related to tricapped trigonal prisms, whose low-connectivity ‘cap’ positions are occupied by the three heteroatom~.~~ A novel ligand rearrangement of cZoso-3,3-(PPh3)2-3,1,2-NiC2BgHll has been 72 C. W. Jung and M. F. Hawthorne, J.C.S. Chem. Comm., 1976, 499. 73 A. J. Welch, J.C.S. Dalton, 1976, 225. 70 Inorganic Chemistry of the Main -Group Elements C(121 P Figure 12 Perspective view of 1,l- bis (trirnethylphosphine)-6,8 -dicarba - 1-pla tinaoctaborane (Reproduced from J.C.S. Dalton, 1976, 225) reported. Heating it under reflux in dry benzene for several hours leads to a quantitative transformation into ~loso-3,8-(PPh,),-3-H-3,1,2-NiC,B,H,,.~~ Me4C4B8H8 reacts with NaC,,H,, NaC5H5, and FeCl, to give at least four isomers of ( ~5-C,H5),Fe,Me,C,B,H,. Crystal structures have been determined for two of these. Both contain 14-vertex polyhedra, but neither is the closo-form expected as a result of electron-counting rules. They contain a five- and a four-membered open face, re~pectively.~~ Ni(cod)(Bu'NC),, Pd(Bu'NC),, and Pt( trans-stilbene)(PEt,), react with Me," (closo-CB,,H,,)- and closo-2-NMe,-2-CBl,H,,, to form the closo-metallocarba- boranes Me,Nf ( l ,l -~-l ,2-MCBl oHl l )~ and 1, 1-L-2-NMe3-1 ,2-MCBloHlo, where L = Bu'NC; M = Ni or Pd; or L = PEt,, M = Pt. The crystal structure of the Pd complex reveals that it contains a 12-atom polyhedron with very distorted icosahedral geometry. The M-C interaction is very weak, with Pd-C(cage)= 2.600(6) A.76 Compounds LTiCl,(L=Cp, x = 2 or 3; L=C8H8, x = 1) react with Na,C,B, Hn+, to give the first reported mixed ligand titanacarbaboranes CpTiC2B10H;,, C8H8TiC2B,H~+2, and C8H8TiC2B,H,+1, where n = 9 or 10. The formal oxidation states of the Ti are + 2, + 3, and + 4, re~pectively.~~ [U(C2B,Hll)2C12]2- is the first reported actinide metallocarbaborane complex. It results from the reaction of UCl, in THF with the 1,2-dicarbollide anion. The crystal structure shows the U atom to have approximately tetrahedral geometry, with pentahupto -dicarbollide ligands (Figure 1 3).78 A series of stable Ir' complexes trans-[(Ph,P),Ir(CO)(a-carb)] has been pre- pared from trans-[(Ph,P),Ir(CO)Cl] and Li(carb), where a-carb = 2-R- 1,2- B,,&H~o or 7-R'-1,7-Bl,C,H~o (R = H or Me; R' = H, Me, or Ph). The complexes are isoelectronic with Vaska's compound, but they react irreversibly with H2.79 74 S. B. Miller and M. F. Hawthorne, J.C.S. Chem. Comm., 1976, 786. " W. M. Maxwell, E. Sinn, and R. N. Grimes, J.C.S. Chem. Comm., 1976, 389. 76 W. E. Carroll, M. Green, F. G. A. Stone, and A. J. Welch, J.C.S. Dalton, 1975, 2263. 77 C. G. Salentine and M. F. Hawthorne, J.C.S. Chem. Comm., 1975, 848. ' I8 F. R. Fronaek, G. W. Halstead, and K. N. Raymond, J.C.S. Chem. Comm., 1976, 279. 79 B. Longato, F. Morandini, and S. Bresadola, Inorg. Chem., 1976, 15, 650. Elements of Group III 71 Figure 13 Molecular structure of the bis[q5-(3)-1,2-dicarbollyl]dichlorouranium(~) dianion (Reproduced from J.C.S. Chem. Comm., 1976, 279) p -a-Carbaboranyl-iridium complexes may also be prepared by both intra- and inter-molecular oxidative addition of terminal B-H bonds to I? complexes. A number of such species were in fact isolated, and the intramolecular addition route is shown in Figure 14.80 Figure 14 Preparation of B-a-carbaboranyl -iridium complexes by intramolecular oxidative (Reproduced by permission from J. Amer. Chem. SOC., 1975, 97, 6388) addition E. L. Hoe1 and M. F. Hawthorne, J. Amer. Chem. SOC., 1975, 97, 6388. 80 72 Inorganic Chemistry of the Main-Group Elements The anion 7-SBloHT1 undergoes an oxidative addition reaction with (PPh,),RhCl, to give a stable complex hydride (PPh,),RhH(SB,oH,o). This can act as a hydrogenation catalyst. The boranes closo-1-SB,H, or closo-l-SB,,H,, react with LJ rCl, where L = PPh, or AsPh,, to form 2-(LJrHC1)-1-SBnH,_,, where n = 9 or 11. These contain B-Ir exodeltahedral bonds.81 Compounds containing B-C Bonds.-Detailed high-resolution measurements have been made on the i.r. spectrum of "BH,CO in the region of v,. Spectro- scopic constants were calculated for this band.*, M.O. calculations have been carried out on BH,CO, using single-determinant approximation methods, and a number of one-electron properties of the molecule have been cal ~ul ated.~~ Ab initio SCF and CI calculations have been performed on BH,CO, using a Gaussian basis set of double-zeta quality. The gas-phase heat of reaction for the reaction (8) was calculated as - 10.98 kcal mol-l (SCF), or - 14.56 kcal mol-' (CI BH, + CO --+ BH,CO ( 8) included). These values were in reasonable agreement with the experimental estimate of - 16.6 kcal rn~l - ' . ~~ B n.m.r. spectra of tetraborane(8) carbonyl at 32.1 MHz have been inter- preted to suggest the presence of two isomers (computer-line-narrowed, proton- decoupled, partially relaxed F.T. spectra were used). The two isomers were respectively endo- and exo- for the position of the CO group with respect to the folded ring, in the ratio of ca. 60 to 40. It was not possible to say whether the two isomers had been formed in the synthesis, and subsequently remained static, or whether the two forms were slowly inter~onverting.~~ BX, (where X=F, C1, or Br) adducts have been characterized for tetra- methylurea and 1,l-bis(dimethy1amino)ethylene (15). A large shift to high field for the CH, proton resonance of the latter on complexation with BF, indicates the loss of olefinic structure. Thus the CH, carbon is the donor site.86 11 ii Me," fGN,Me I I Me Me (15) He (I) photoelectron spectra of Me,_,BX, (X = F, C1, or Br; n = 1 or 2) have been analysed by analogy with those of BX, and BMe,, on the basis of ab initio M.O. calculations. Some correlations were found between orbital and ionization energies, w-charge densities, and llB chemical shifts.87 " D. A. Thompson and R. W. Rudolph, J.C.S. Chem. Comm., 1976, 770. 82 C. PBpin, L. Lambert, and A. Cabana, J. Mol. Spectroscopy, 1976, 59, 43. 83 W. C. Ermler, F. D. Glasser, and C. W. Kern, J. Amer. Chem. Soc., 1976, 98, 3799. 84 T.-K. Ha, J. Mol. Structure, 1976, 30, 103. 85 E. J. Stampf, A. R. Garber, J. D. Odom, and P. D. Ellis, Inorg. Chem., 1975, 14, 2446. '' J. S. Hartman and R. R. Yetman, Canad. J. Chern., 1976, 54, 1130. '' H. - 0. Berger, J. Kroner, and H. Noth, Chem. Ber., 1976, 109, 2266. Elements of Group III 73 Coupling constants [1J(13C-11B) and 'J (13C-lH)] and chemical shifts (6l'B and 6°C) have been determined for R,-,BX, (R=Me; X=NMe,, OMe, or SMe; n = 0-3). Double-and triple-resonance experiments 'H-(l 'B}, 'H_(13C}, and 'H- {"B, 13C} were used.88 Neutron diffraction and X-ray diffraction have been used to elucidate the Li- H-C interactions in LiBMe,. The structure comprises planar sheets of Li atoms, bridged by BMe, groups through B-Me-Li and multi-centre fragments. Mass spectra showed that the LiBMe, is also associated in the vapour phase.89 Vibrational assignments have been proposed for triallyl-, tricrotyl-, and trimethy l al l yl -b~ron.~~ Aminoboranes and Other Compounds containing B-N Bonds.-lH n.m.r. meas- urements (120-350 K) for Me3NBH3 have been used to elucidate molecular motions in the adduct. Minima in Tl found at 157 and 259 K could be attributed to three-fold reorientation of each of the three Me groups and the borane group, and to three-fold reorientation of the whole molecule about the B-N axis, respe~tively.~' The Simmons-Smith reagent (an organometallic complex formed between Zn and CH212) reacts with Me3NBH, to give ready methylene transfer and resultant formation of BMe3.92 Hydrolysis of Me3NBF3 occurs via both acid-independent and acid-dependent pathways, each of which is first-order in substrate.93 C n.m.r. spectra have been reported for the Me, adducts of mixed trihalides of boron, viz. Me3NBX,Y3-, ( n = 0-3; X,Y =F, C1, Br, or I). 6(13C) moves downfield for heavier halogens, reflecting the order of Lewis basicity. No 13C-11B couplings were detected.94 'H n.m.r. spectra have been recorded for a number of Me,N and HEt2N adducts of halogenoboranes, prepared from amine-BH, adducts by the reaction of HX or X,. Shifts to lower field with increasing size and number of halogens on the B could be ascribed to steric effects and not (as previously thought) to inductive effects. The diethylamine-halogenoborane spectra were very complex, but computer analyses of the spectra allowed assignments consistent with prefer- red rotational configurations to be made.95 The adducts L,BH2X, where L = py, NMe,, or PMe,; X = F, C1, Br, I, NCS, or NCSe, have been prepared and characterized. An empirical correlation was proposed between JBH, the electronegativity of X (Ex), and the estimated B-X bond distance (Dx): 13 (for L= Me3N) JBH = 3.336Ex + 36.4260x + 47.233 (for L=py) JBH=34.583Ex+18.116Dx-10.328 88 W. McFarlane, B. Wrackmeyer, and H. Noth, Chem. Ber., 1975, 108, 3831. 89 W. E. Rhine, G. Stucky, and S. W. Peterson, J. Amer. Chem. k., 1975, 97, 6401. 90 W. Briiser, S. Schroder, and K. Witke, Z. anorg. Chem., 1976, 421, 89. 91 T. T. Ang and B. A. Dunell, Canad. J. Chem., 1976, 54, 1087. 92 B. R. Gragg and G. E. Ryschkewitsch, Inorg. Chem., 1976, 15, 1988. 93 C. Weidig, J. M. Lakovits, and H. C. Kelly, Inorg. Chem., 1976, 15, 1783. 94 J. M. Miller and T. R. B. Jones, Inorg. Chem., 1976, 15, 284. 95 W. H. Myers, G. E. Ryschkewitsch, M. A. Mathur, and R. W. King, Inorg. Chem., 1975,14,2874. 74 Inorganic Chemistry of the Main -Group Elements There was almost no change in JBH with X for L=PMe,. No theoretical justification has been given for these relationship^.'^ A closely related series of adducts, uiz. L,BH21, where L = NMe,, py, 3-Mepy, 4-Mepy, or PPh,, has also been reported. The addition of suitable amines or phosphines to solutions of these adducts in benzene leads to the formation of boronium salts containing two different donors co-ordinated to B : [LL'BH2]+I-, where L'=PMe,, PPh3, NMe,, etc. 'H and "B n.m.r. data were listed for these wherever possible.97 A number of reactions of NMe,,BH,I in liquid NH, have been investigated. The compound itself gives [BH2(NH3),]I slowly, and its reaction rate is increased by the presence of a number of halide salts. NaCN gives mainly NH3,B(CN)H2, while NaNH, leads to the formation of polymeric [BH2(NH2)],, NMe,,BHX, (where X = Br or I), and NMe,,BBr,, as well as NMe,,BH,I; all react with Na in liquid ammonia to give, for example, [BH2(NH2)], and, for NMe,,BH21, to give NMe,,BH3 ." Some (amine),B3H7 adducts, where amine=MeNH, or Me,NH, may be pre- pared by the reactions (9) and (10). N.m.r. data were collected for all of the series MenNH3-,,,B3H7." B,Hlo +THF + THF,B3H7 + $B,H, (9) THF,B3H7 +amine * amine,B,H, +THF (10) 1 : 1 Complexes are formed between triarylboranes and both hydrazine and semicarbazide, NH2NHCONH2.100 Compounds HXB(NMe,), where X = C1or Br, are prepared from (H2BNMe,), and HgX2 at 110 "C. Vapour-pressure and gas-phase molecular weight data show that they are present as equilibrium monomer/dimer mixtures in the gaseous phase, with a preponderance of the latter at 25 "C. When X = Br, the dimer is the more stable.''' BX3 and N(SiMe,), react, under a variety of conditions, to give MeBX,, (Me,Si),N-BMeX, (Me,Si)2N-BX2 (X = F, C1, or Br), or mixtures of these. The hitherto unknown (Me,Si),N-BMe, and (Me,Si),N-BMeBr were also pre- pared.lo2 (CF3S),NH reacts with BX3 (X = C1 or Br) to form X,B-N(SCF,),. **B n.m.r. and i.r. data, together with an X-ray structure determination of the adduct Me3N,C12B-N(SCF,),, show that the B-N(SCF3), bond is very long and weak. Other spectroscopic data (lH and "F n.m.r., Raman, and mass-spectral) have also been listed.", Difluoro(difluorophosphinoamino)borane has been prepared as shown in 96 M. L. Denniston, M. A. Chiusano, and D. R. Martin, J. Inorg. Nuclear Chem., 1976, 38, 979. 97 M. L. Denniston, M. A. Chiusano, J. Brown, and D. R. Martin, J. Inorg. Nuclear Chem., 1976,38,379. 98 P. J. Bratt, M. P. Brown, and K. R. Seddon, J.C.S. Dalton, 1976, 353. 99 A. R. Dodds and G. Kodama, Inorg. Chem., 1976, 15, 741. loo I. I. Lapkin, S. E. Ukhanov, and G. A. Yuzhakova, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1479. lo' 0. T. Beachley and B. Washburn, Inorg. Chem., 1976, 15, 725. lo* W. Haubold and U. Kraatz, Z. anorg. Chem., 1976, 421, 105. lo3 A. Haas, M. Haberlein, and C. Kruger, Chem. Ber., 1976,109, 1769. Elements of Group III 75 reaction (11). This new species has been characterized by its mass, photoelectron, n.m.r., and vibrational spectra.lo4 PF2(NH2) +BF, + PF,(NH,),BF, + BF,[NH(PF,)] +HF A new triborylamine, whose stability is not dependent on 7r-back-co-ordination from the boron substituents, has been synthesized from (16a) by the action of N(SnMe,),. The resulting species (16b) is formed by stepwise replacement of the trimethylstannyl groups, and the intermediate compounds can be isolated. The boryl groups withdraw electron density from the nitrogen by 7r-interactions, leading to downfield '*N n.m.r. shifts. The compound is a powerful boronating agent.lo5 The isocyanoborane adduct Me,N,BH,NC has been prepared for the first time as a major product from the reaction of KAg(CN)2 with Me,N,BH,I. The adduct forms complexes with neutral compounds, e.g. with Mn(CO),Br it produces ( 17). lo6 (11) K[(.rr-Cp)Fe(CO)(CN),] reacts with BX3 (X=F, Cl, Br, H, or Ph) to give Fe" species containing CNBX, or CNBX2NC- ligands. When X=F, Br, or Ph, these are stable compounds (18) containing a 12-membered ring.lo7 X \B/X (18) Reduction of dichloro-NN'-ethylenebis(salicylideneiminato)titan~~(~) by BH, gives a compound which analyses as [C16H16N202Ti(BH3)2]2. The crystal structure of this showed the presence of amine-boranes as donor groups, and the novel unit (19) in the complex.1o8 D. E. J. Arnold, E. A. V. Ebsworth, and D. W. H. Rankin, J.C.S. Dalton, 1976, 823. lo' W. Storch and H. Noth, Angew. Chem. Internat. Edn., 1976, 15, 235. '06 J. L. Vidal and G. E. Ryschkewitsch, J.C.S. Chem. Comm., 1976, 192. lo' J. Emri, B. Gyori, A. Bakos, and G. Czisa, J. Organometallic Chem., 1976, 112, 325. lo* G. Fachinetti, C. Floriani, M. Mellini, and S. Merlino, J.C.S. Chem. Comm., 1976, 300. 76 Inorganic Chemistry of the Main-Group Elements The thermal decomposition of diborylamines to give borane and a borazine derivative is much more difficult when the B atoms are incorporated in a five-membered ring. The chemistry of a number of such systems, e.g. (20), has been A number of new, water-stable borane cations of betaines and amino-acid esters have been characterized, i.e. Me,NBH,NMe,(CH,),CO,Et+, where n = 2, 3, or 4, and Me3NBH2O2C(CH2),NMe:, where n = 1-4. The qualitative order of stability of the betaine cations towards aqueous base is n = 1,2 > n = 3,4, while for the ester cations it is n = 2,3,4> n = 1,'" Compounds containing B-P or &As Bonds.-The reaction of H3P,BH3 with liquid NH3 at - 45 "C gives an ionic solid NH4[H2P(BH3),]. Higher temperatures lead to increasing amounts of the covalent H3N,BH3 also. The amines MeNH, and Me,NH react differently, forming predominantly covalent species at or below -45 "C (i.e. MeH,N,BH, and Me,HN,BH,) and increasing amounts of ionic material at higher temperatures. A mechanism involving the anion H2PBH, has been put forward to rationalize these observations."' The microwave spectra of four isotopic variants of H3P,BF3 have been anal- ysed, assuming that the molecule adopts the staggered conformation, that the P-H bond length is 1.40 A, and that the HPB angle is 117 '. The following results were obtained: r(P-B) = 1.921 * 0.007 A; r(B-F) = 1.372k0.002 A; and LFBP = 106.69 f 0.38 ". The Stark splittings were consistent with a dipole mo- ment of 3. 73i ~0. 30 D in the ground state. The barrier to internal rotation was calculated to be 3.39 f 0.40 kcal mol-1.112 N.m.r. studies on some adducts H,B,PXYZ have been used to compare 'JBH, 'JBP, and 6l'B with parameters derived from enthalpies of reaction of B2& with the parent phosphines. There is no simple correlation between the coupling constants 'JBp and the stabilities of the The reduction of trimethyl phosphite-borane by sodium naphthalide produces a new type of diphosphine derivative. The isomer which apparently explains all of the observed properties of the compound is (21).'14 The preparation and n.m.r. characterization of two new P-B adducts, uiz. PW2P-BH3 and (22), have been described.''' Another new series of P-B adducts has also been reported: these are lo9 H. Noth and W. Storch, Chem. Ber., 1976, 109, 884. N. E. Miller, Inorg. Chem., 1976, 15, 1735. E. A. Dietz, K. W. Morse, and R. W. Parry, Inorg. Chem., 1976, 15, 1. J. D. Odom, V. F. Kalasinsky, and J. R. Durig, Inorg. Chem., 1975, 14, 2837. G. Jugie, C. Jouany, L. Elegant, J. F. Gal, and M. Azzaro, Bull. SOC. chim. France, 1976, 1. L. A. Peacock and R. A. Geanangel, Inorg. Chem., 1976, 15, 244. C. Jouany, G. Jugie, G. V. Roschenthaler, and 0. Stelzer, J. Inorg. Nuclear Chem., 1976,38, 1383. 113 114 115 Elements of Group III 77 R3PCH,,BF3 (where R=Ph, Me, or Et) and Me,PCHSiMe,,BF,. 31P, '*B, 19F, and 'H n.m.r. spectral data were listed."6 'H n,m.r. studies of exchange reactions in the systems PMe,Ph,BMe,, PMe,(NMe,),BMe,, PMe2But,BMe3, and PMe,,BMe,Ph (the BMe,Ph having been prepared from BMe,Cl and HgPh,) have been reported. In CH2C12 at 27 "C, the basicities towards BMe, are in the order117 NMe3 =r PMe, > PMe,Bu' = PMe,(NMe,) > PMe,Ph >>P(CH,Ph), > PMe,(CF,) = PMe30 = PMePh,. P n.m.r. spectra of (4-X-C6H4),PC13-,, (3-x-C&),Pcl3-, (X = F, C1, or H; n=1 , 2, or 3), and their adducts with BC13 and BBr, have been obtained. Increases in chemical shift that occur on complexation have been interpreted in ierms of incrfased charge on the P, and resultant charge delocalizations: ~ ( p- p) Ar-P, P-Cl, and m( p- d) m, ~ . ' " Methods of preparation of members of the series R~As-BR; have been reported, where R' = Ph, R2 = Me, ; R1 = Ph, R; = MeNCH,CH,NMe; R' = Me, RZ= MeNCH,CH,NMe, and of the series Me,As-BR'R', where R1 = R2 = Ph; R' = R' =Me; R' =Me, R2 = Br, and of [Me,AsBH,],,, where n = 3 or 4. Mem- bers of the first series are monomeric. The compounds Me,BAsMe, and Me,AsBBrMe are thought to be trimeric. I.r., mass spectral, and n.m.r. data are consistent with these ~~n c l ~~i o n ~. ~~~ The vapours above As-B mixtures have been examined by Knudsen-cell mass spectrometry. BAS and &As vapourke with decomposition to give a vapour consisting chiefly of As, and As,. The following heats of formation were deduced: AWBAs; 298 K) = -8.5 f 2.0, AWB,As; 298 K) = -16.6 f 2.0 kcal mo1-1.120 31 Compounds containing B-0 Bonds.-Ab initio M.O. calculations on H3BOH2, (H,BOH),, and some related molecules suggest that the bonding is very similar to that in the aluminium analogues. The reorganization energy in BH,OH is respon- sible for a very low dissociation energy of the (BH,OH), A comparative thermochemical study of B202 (g), B2S2 (g), A1,0, (g) with other Al-family chalcogenides M2X2, where X = S, Se, or Te, has revealed that all of these possess a bent structure (23a), rather than the cyclic structure (23b) which had been proposed previously. Vibrational wavenumbers and free-energy func- tions were calculated for B202 and A1202.122 Electron-difli-action results for gaseous dimethylboric anhydride, Me,BOBMe,, E. Fluck, H. Bayha, and G. Heckmann, Z. anorg. Chem., 1976, 421, 1. 11' K. J. Alford, E. 0. Bishop, and J. D. Smith, J.C.S. Dalton, 1976, 920. 11' E. Muylle and G. P. van der Kelen, Spcrrochim. Acta, 1976, 32A, 599. '19 R. Goetze and H. Noth, Z. Nafurforsch., 1975, 30b, 875. 116 A. S. Alikhanyan, A. V. Steblevskii, A. F. Radchenko, and V. I. Gorgoraki, Russ. J. Inorg. Chem., 1975, 20, 1709. K. M. Maloney, S. K. Gupta, and D. A. Lynch, 1. Inorg. Nuclear Chem., 1976, 38, 49. 120 lZ1 E. Flood and 0. Gropen, J. Organometallic Chem., 1976, 110, 7. 122 78 Inorganic Chemistry of the Main-Group Elements are consistent with the presence of a C2BOBC, skeleton of C2 symmetry. r,(B-0) = 1.359(4), r,(B-C) = 1.573(4) A.123 The barrier to internal rotation has been calculated for diborane peroxide, H3B02BH3, by ab initio methods. The potential-energy curve shows only one minimum, at the trans-configuration. The lack of a second minimum may be due to steric repulsions, and may suggest a degree of conjugation in the The effects of organic diluents (benzene, hexane, etc.) on the extraction of H,BO, from aqueous solutions by long-chain aliphatic alcohols have been investi- gated. It was not easy to rationalize the observed trends? Electron-diffraction studies of B(OMe), have given data that are consistent with a B(OC), skeleton, of C,, symmetry. The following parameters were obtained: r(B-0) = 1.367(4), r(0-C) = 1.424(5) A, LBOC = 121.4(0.5) o.126 Equilibria in the system MF-B(OMe),-MeOH, where M=Li, Na, K, Rb, or Cs, have been investigated, and methods for the formation of the complexes M[BF(OMe),] defined. Solubility, i.r., and n.m.r. data were reported for a number of the Strontium calcium diborates and strontium diborate are isostructural, the former being produced by the replacement of Sr by Ca in the Sr[B(OH),], unit of the latter.12' Tetrakis(dimethoxybory1)silane has been prepared by reaction (12). It can be purified by dissolving in ether, and then recrystallizing from 1 : 1 ether-light petroleum. 129 SiCI, + 8Li +4CIB(OMe), -+Si[B(OMe),], (12) The structure of CaCl,,Ca(BO,), consists of Ca2', Cl-, and Bog- in distinct, mutually alternating anionic and cationic layers parallel to (102). The BO, units are very nearly planar, and the B-0 distances are 1.403, 1.391, and 1.390 A.130 RbNbB206 is isotypic with TlNbB,06, but tilting of the octahedral chains in the a directioh reduces the symmetry from Pn2,rn to The crystal structure of synthetic anhydrous chondrodite, Al,Co(BO,),O,, has been determined. The cation distribution among the three independent octahedral G. Gundersen and H. Vahrenkamp, J. Mol. Structure, 1976, 33, 97. E. E. Vinogradov and L. A. Azarova, Russ. J. Inorg. Chem. , 1975, 20, 964. G. Gundersen, J. Mol. Structure, 1976, 33, 79. 123 124 0. Gropen and H. H. Jensen, J. Mol. Structure, 1976, 32, 85. 125 l Z7 V. N. Plakhotnik, N. G. Parkhomenko, and V. V. Evsikov, J. Gen. Chem. (U. S. S. R. ), 1975,45, 1745. lZ8 G. K. Gode, N. P. Ivchenko, and E. N. Kurkutova, Russ. J. Inorg. Chem. , 1975, 20, 1736. 130 Z. Zak and F. Hanic, Actu Cryst., 1976, B32, 1784. R. J,. Wilcsek, D. S. Matteson, and J. G. Douglas, J.C.S. Chem. Comm., 1976, 401. A. Baucher, M. Gasperin, and B. Cervell, Actu Cr y s t , , 1976, B32, 2211. 129 131 Elements of Group III 79 sites shows that the chondrodite structure should be written as (A1.88&,,& (A12)(Co0.89A10.11)(B04)202. The average atomic distances are: B-0 1.493, Al(1)-0 1.944, Al(2)-0 1.911, and Co- 0 2.O64A.l3' The structure of inderite, Mg[B,03(OH),](H,0),,H,0, is built up of [B303(OH)s]z- groups and Mg(OH),(H,O), octahedra, forming discrete molecules by sharing two OH groups.133 Raman spectra have been used to detect and identify the polymeric units B,O,(OH),, B3o3(OH)4, B4OS(OH)2-, and B303F:- in solutions containing H3B03, NaBF,OH, and NaF.13, Raman spectra for a single crystal of K[Bs06(OH),],2H,0 have been used to obtain a vibrational assignment for the B5Ol0 unit, in terms of idealized D2,, crystal geometry. The stretching vibrations could be interpreted in terms of BO, and BO, group vibrations, but the bending modes were heavily mixed.135 Nasimite, Na2[B5O8(OH)],2Hz0, possesses a structure based on sheets in the bc plane, formed by polymerization of [B,08(OH)]2- units.136 The crystal structure of another borate mineral, garrelsite, NaBa3Si2B701,(OH)4, has been determined. This structure has a three-dimensional framework of silicoborate sheets, and Ba-0 polyhedral layers. The silicoborate sheets com- prise a new type of silicoborate chain (with two types of alternating Si and B tetrahedral four-membered rings), the pentaborate anion B,O:,, and octahedrally co-ordinated Na+.137 Solubilities have been determined at 20 and 30°C in the system LiB0,-LiCl- H20.138 The phase diagram for KB0,-KCI-H,O has also been con~tructed.'~~ Studies of solubility in the B,O,-CaO-H,O system have revealed the existence of the borate 2Ca0,B,0,,Hz0 at temperatures above about 80 OC. l 4 ' "B and '07Pb n.m.r. spectra of glasses in the Pb0-B203-Si02 system show that no significant number of BO, units are present. The Pb2+ions are shared between the B-0 and Si-0 The phase diagram has been determined for the system B,O,-Na,O,B,O,- Na,0,W0,-W0,.142 1 : 1 Complexes have been isolated from reactions between dicarboxylic esters and either BCl, or AlCl,. Determinations of molecular weight in benzene solution point to simple monomeric formulations, confirmed by the small molar conduc- tances in PhNOz Tetrahedral complexes (24) form when benzoin or its 2,2'-substituted deriva- tives react with B or Al chlorides or bromides. On heating the aluminium halides, dimeric [AlX,2(benzoin)], complexes are formed, in which the aluminium atoms 132 J. J. Capponi and M. Marezio, Actu Cryst., 1975, B31, 2440. 13' E. Corazza, Actu Cryst., 1976, B32, 1329. L. Maya, Inorg. Ge m. , 1976, 15, 2179. V. Devarajan, E. Grafe, and E. Funck, Spectrochim. Actu, 1976, 32A, 1225. 134 135 136 E. Corazza, S. Menchetti, and C. Sabelli, Actu Cryst., 1975, B31, 2405. 137 S. Ghose, C. Wan, and H. H. Ulbrich, Actu Cryst., 1976, B32, 824. 13* V. G. Skvortsov, Russ. J. Inorg. Chem., 1975, 20, 1743. 13' V. G. Skvortsov and R. S. Tsekhanskii, Russ. J. Inorg. Chem., 1975, 20, 1426. 140 B. A. Nikol'skii and Yu. S. Plyshevskii, Russ. J. Znorg. Chem., 1975, 20, 1240. 14' K. S. Kim, P. J. Bray, and S. Merrin J. Chem. Phys., 1976, 64, 4459. 142 V. T. Mal'tsev and V. L. Volkov, Russ. J. Inorg. Chem., 1975, 20, 1217. 143 K. C. Malhotra and S. M. Sehgal, Indian J. Chem., 1975, 13, 153. 80 Inorganic Chemistry of the Main-Group Elements Ph / are in octahedral co-cordination. The compounds from InCl, and TIC1, have the same MC1,,2benzoin stoicheiometry, but they are formulated on spectroscopic evidence as the ionic compounds [M(benzoin),]' MCL .14, Compounds containing B-S or B-Se Bonds.-Ab initio M.O. calculations have been carried out on thioborine, HBS, yielding values for the ionization potentials, force constants, and geometric parameters which are in fair agreement with experiment. 145 Similar calculations were carried out to determine the barrier to internal rotation in (25). The low barrier calculated for the anti-form was consistent with the electron-diffraction data for the Me, derivative. The results were consistent with considerable electron delocalization in the planar form.146 H I /"-" ,s-s' H H--B\ (25) The electron-diffraction data referred to for Me,BSSBMe, gave the bond lengths: r ( S - S ) 1.805(5), r(S-S) 2.078(4) A. The fact that the C4B,S, skeleton is planar indicates that there is some n-bond ~haracter.'~' Electron diffraction reveals that bis(methylthio)methylborane, MeB(SMe),, possesses a skeleton which is at least nearly planar. Only a syn-anti-form could be detected. The value of r(B-S) was found to be 1.796(7)81.148 Bromoboranes react with Hg(SCF3), to give thermally unstable CF3SB species. These may be stabilized by formation of tetraco-ordinate boron, or, as in (Me,N),B(SCF,), by electron ~aturati 0n.l ~~ The molecular structures of X,B(SMe), where X = C1or Br, have been deter- mined from X-ray difiaction results. They are trimers, not dimers as previously thought, with six-membered rings in the chair conformation, as shown in (26). 144 K. C. Malhotra and S. C. Chaudhry, Indian J. Chem., 1975, 13, 933. 14' 0. Gropen and E. Wislbff-Nilssen, J. Mol. Structure, 1976, 32, 21. 14' 0. Gropen, Acta Chern. Scand. ( A) , 1975, 29, 873. 14' R. Johansen, H. M. Seip, and W. Siebert, Acta Chem. Scand. ( A) , 1975, 29, 644. 14' S. Linday, H. M. Seip, and R. Seip, Acta Chem. Scand. ( A) , 1976, 30, 54. 149 A. Haas and M. Haberlein, 2. anorg. Chem., 1976, 424, 20. Elements of Group III 81 The chief bond lengths are: r(B-X) 1.80 (Cl), 1.96 (Br); r(B-S) 1.95; r(S-C) 1.84 A."" Tetramethylthiourea and tetramethylselenourea form 1 : 1 complexes with BF,. In solution they are partly ionized as (donor),Bc BE. Addition of BF, to such solutions at low temperatures leads to the complete formation of (donor),BG B,F; .15' Boron Halides.-Non-empirical valence-electron (NEVE) M.O. calculations have been performed on all of the monohalides of Group I11 (B to In, F to I). The trends in calculated properties are as expected, and the results agree well with available all-electron ab initio results, which are much more costly in computer time. 152 Equilibria have been investigated in the system LiBF,-H,O. Two crystalline modifications of hydrated LiBF, were f 0~nd. l ~~ A number of novel complexes have been reported in which boron halides are co-ordinated to Pt" or Pt". Reaction (13) is an example. This is apparently a true (Ph,P),Pt(GH,) + 2BF3 + (Ph,P),Pt(BF& +C2H4 (13) four-co-ordinate Pt" complex (27), as it is monomeric in CH,Cl, and it shows v(BF) of co-ordinated BF, in the region 1OOO-llOOcm-'. The BF, can be replaced quantitatively by BCl,, in agreement with known relative Lewis acidities. lS4 Ph,P LptPBF3 / \ Ph,P BF3 (27) Mossbauer studies on (C5H5)Fe(C5H4BX2), where X = F, C1, Br, or I, show that the quadrupole splitting AEQ decreases with increasing Lewis acidity of the dihalogenoboryl group, although the isomer shift remains constant.155 He (I) photoelectron spectra of mixed halides of boron, BX,X',-,, where X, X' = C1 or F, n = 1 or 2, have been recorded and assigned, using the results of studies of mixtures of BX3+BX5. The mixed halides were present in essentially lL10 S. Pollitz, F. Zettler, D. Forst, and H. Hess, Z. Naturforsch., 1976, 31b, 897. IL12 J. B. Peel and K. Terauds, Inorg. Chem., 1976, 15, 1051. lS3 V. N. Plakhotnik, V. B. Tul'chinskii, V. V. Varekh, and S. M. Slizkii, Russ. J. Inorg. Chem., 1975,20, lL14 H. Fishwick, H. Noth, W. Petz, and M. G. H. Wallbridge, Inorg. Gem. , 1976, 15, 490. lL15 J. Pebler, W. Ruf, and W. Siebert, Z. anorg. Chem., 1976, 422, 39. J. S. Hartman, G. J. Schrobilgen, and P. Stilbs, Canad. J. Chem., 1976, 5 4 1121. 1385. 82 Inorganic Chemistry of the Main-Group Elements statistical proportions. The microwave spectrum of BClF, was also recorded, and the resulting molecular structural parameters were compared with data computed by ab initio methods.lS6 Single crystals of Ge react with BCl, vapour in the temperature range 500- 900°C as shown in reaction (14).15' The halides BX, (X = C1or Br) react with tetra-alkyl-lead (alkyl =Me or Et) to give the series of organohalogenoboranes R,BX+, (rn = 1-3). 1.r. and Raman data for these species, and for the fluoro-analogues, have been listed and assigned, as were those for PhBX, (X=F, C1, or Br). A number of compounds RBXY could be detected spectroscopically in mixtures of the simple halogeno- derivatives.15' The mixed species BX,(NCS),-,, where X = C1, Br, or I; n = 1 or 2, can be prepared by reactions of BX, with B(NCS), or metal isothiocyanates. Rapid redistribution reactions preclude the isolation of solid compounds, but spectro- scopic data have been reported. The vibrational spectra are consistent with the presence of B-NCS units.1s9 Cyclopentadienylsilanes contain a very reactive Si-C bond, and they can be used to prepare a number of cyclopentadienyl-boranes, by the general reaction ( 1 9 , where X = C1or Br. Among the compounds synthesized were (28a-c), and R-CpSiMe, + BX, + R-CpBX, + Me,SiX (15) in addition, the method could be modified to yield the diboryl derivatives (28d), in which X = C1, Br, or I.16o 1.r. and Raman spectra of B4C14can be interpreted in terms of Td molecular symmetry (tetrahedral B4 cage, and the B-Cl bonds lying along the C3 axes) for solutions, but D,, for the crystal. All eight (Td) fundamentals were assigned. A normal-co-ordinate analysis showed that the A, modes are extensively mixed, and that the B-C1 and B-B stretching force constants are 4.08 and 2.3 mdyn A-', respectively, the latter being very 10w.l ~~ lS6 H. W. Kroto, M. F. Lappert, M. Maier, J. B. Pedley, M. Vidal, and M. F. Guest, J.C.S. Chem. 15' G. M. Gavrilov, N. A. Eliseeva, and V. I. Evdokimov, Russ. J . Inorg. Chem., 1975, 20, 1136. lS9 J. Dazord, H. Mongeot, H. Atchekzai, and J. P. Tuchagues, Canad. J. Chem., 1976, 54, 2135. 160 P. Jutzi and A. Seufert, Angew. Chem. Internat. Edn., 1976, 15, 295. 16' F. R. Brown, F. A. Miller, and C. Sourisseau, Spectrochim. Acta, 1976, 32A, 125. Comm., 1975, 810. W. Haubold and J. Weidlein, Z. anorg. Chem., 1975, 420, 251. Elements of Group III 83 Ferrocene reacts with BX, (X = Br or I) to give 1,l'-bis(dihalogenobory1)- ferrocenes. CpMn(CO),, on the other hand, readily gives the bis-borylated derivative directly. 162 Boron-containing Heterocycles.-He (I) photoelectron spectra for 30 compounds containing isoelectronic, six-7r-electron, five-membered B-N rings (some also contained ring 0 and/or S atoms) have been reported. The data were consistent with cyclic 7r-bonding, which decreases on replacing ring N atoms by S.16, A number of bis( 1 -substituted-borabenene)iron complexes have been pre- pared as shown in Scheme A 1, where R = Ph, Me, CMe,, or Br. The final products Bu / ' B u 0 R 0 R QR I Fe Reagents: i, RBBr2; ii, RLi; iii, Feci, Scheme 1 may be acetylated in exactly the same way as ferrocenes. The 57Fe Mossbauer spectrum of the complex with R = Ph shows that the quadrupole splitting is lower than in ferrocene. This suggests that the 1-phenylborabenzene is more effective at withdrawing electron density from the Fe atom than is cyclopentadienyl. 164 Bis(borinato)cobalt complexes CO(C~H~BR)~, where R = Ph or Me, react with alkali-metal cyanides MCN, where M=Na or K, to give alkali-metal borinates M(C,H,BR). These are useful synthetic reagents, and may be used to prepare RU(C~H~BR)~, OS( C~H~BP~) ~, Rh(l,5-C8H12)(C5HsBR), and PtMe3(C5H5BPh).165 B n.m.r. spectra of heterocyclic boron compounds containing B-N or B-0 bonds are inconsistent with their having aromatic character.166 The He (I) photoelectron spectrum has been reported for the monomer of (29). 167 The results of ab initio M.O. calculations, using a very restricted basis set, indicate that it may be possible to obtain in practice 'bond stretch' isomers in the system (30). When the N and B are replaced by carbon atoms, the species at the right-hand side can never be isolated.168 11 162 W. Ruf, T. Renk, and W. Siebert, 2. Naturforsch., 1976, 31b, 1028. lb3 J. Kroner, D. Nolle, H. Noth, and W. Winterstein, Chem. Ber., 1975, 108, 3807. A. J. Ashe, E. Meyers, P. Shu, T. von Lehmann, and J. Bastide, J. Amer. Chem. Soc., 1975, 97, 6865. 16' G. E. Herberich, H. J. Becker, K. Carsten, C. Eengelke, and W. Koch, Chem. Ber., 1976,109,2382. 166 B. M. Mikhailov and M. E. Kuimova, J. Organometallic Chem., 1976, 116, 123. 16' M. N. Paddon-Row, L. Radom, and A. R. Gregory, J.C.S. Chem. Comm., 1976, 427. H. Bock and W. Fuss, Chem. Ber., 1976, 109, 799. 84 Inorganic Chemistry of the Main-Group Elements Synthetic routes have been described for the new boron-containing hetero- cycles (31), (32), and (33).169 (33) The reaction of (34) with PhNCO or PhNCS involves a ring-expansion process to form the new eight-membered B-N-C heterocycles (33, in which X = 0 or S.l7O Reduction of [(Me,N),BH,]’ I- by potassium in 1,2-dimethoxyethane produces 1,1,3,3-tetramethyl-1,3-diazo~a-2,4-diboratocyclopentane (36). This reacted with HX (X=Cl, Br, or I), giving halogenation at the ring position 4.171 \ IMe H Me Ph N-B\Ph N HN/ ~\ NH H2C’ NPh H,C’ ‘BH, H*C, CH2 H,C, H2B-N-Me I I \ I I I H2 C - A x H2 H Me I (35) (36) (34) An alternative route to (36) involves the reaction of NMe3,BH2X, where X = Br or I, with Na-K alloy. This proceeds via the reactive intermediate [Me3NBH2 :I-. This reaction also forms a six-membered-ring analogue, under appropriate condi- t i o n~. ~~~ Compound (37) reacts with py, 4-Mepy, 2-Mepy, or NMe, to give new boron-containing cations, such as (38).173 + 16’ R. Goetze and H. Noth, Chem. Ber., 1976, 109, 3247. 17’ B. R. Gragg and G. E. Ryschkewitsch, Inorg. Chem., 1976, 15, 1201. 17* B. R. Gragg and G. E. Ryschkewitsch, I mg . Chem., 1976, 15, 1209. 173 B. R. Gragg and G. E. Ryschkewitsch, Inorg. Chem., 1976, 15, 1205. K. D. Miiller and U. W. Gerwarth, J. Organometallic Chem., 1976, 110, 15. Elements of Group III 85 A number of B-N-Si cyclic systems have been prepared for the first time, by a variety of routes, chiefly (i) the reaction of N-lithio-aminoboranes with bis- (chlorosilylamines), (ii) transamination of (aminoborylamino)silanes, and (iii) con- densation of Me,Si(NHMe), and alkylbis(dimethy1amino)boranes. 'H, llB, and N n.m.r. data suggest that the silaborazine ring in, e.g., (39) is n~n- pl anar.~~~ The crystal structure of (40) shows that the molecule possesses D2 symmetry. 14 The two CBNBC planar units are twisted by 18" with respect to each other. The mean B-N bond distance is 1.42 A.175 The synthesis of a series of new boron chelate compounds (41), in which the ligands are carbinolamidines R1CH(OH)NR3C(=NR3)R2, formed as inter- mediates in the reaction between amidines R3NHC(=NR3)R2 and aldehydes R'CHO, has been A determination of the crystal structure of 3,6-bis(dimethylamino)-1,2,4,5- tetramethyl-1,2,4,5,3,6-tetra-azadiborine (42) shows that the B2N4 is non-planar, as expected for a heterocycle containing eight w-electrons, with overall C, molecular symmetry, although the symmetry of the ring approximates to D2. The latter agrees with earlier CNDO/S calculations. The bond lengths within the ring are: r(B-N) 1.43, r(N-N) 1.43 A.177 A vapour-phase Raman spectrum of borazine has been obtained under medium resolution. Band contours of the E" fundamentals were measured, enabling estimates to be made of the Coriolis coupling constants Li. It is the first time that a reasonably complete assignment has been made of the gas-phase vibrational wavenumbers of B3N3H6.178 In addition, a detailed vibrational assignment has been made for N-trimethyl- borazine, (BHNMe),. Data from a number of isotopically labelled species were used, i.e. (BDNMe),, ("BHNMe),, and CD, derivatives. The results were used to 174 H. Noth and W. Tinhof, Chem. Ber., 1975, 108, 3109. 17' H. Noth and R. Ullmann, Chem. Ber., 1975, 108, 3125. 176 V. A. Dorkhov, V. I. Seredenko, and B. M. Mikhailov, J. Gen. Ge m. (U.S.S.R.), 1975,45,1737. 177 J. C. Huffmann, H. Fusstetter, and H. Noth, 2. Naturforsch., 1976, 31b, 289. B. Roussel, A. Chapput, and G. Fleury, J. Mol. Structure, 1976, 31, 371. 178 86 Inorganic Chemistry of the Main-Group EZements perform a normal-co-ordinate analysis on the molecule, which compared very favourably with those reported previously for other borazine compounds. The B-N stretching force constant was calculated to be 4.98 mdyn A-l, compared to 5.46 in borazine itself .179 Two new N-halogenoborazines can be isolated as products of the reaction between BF3 and N-halogenosilylamines. The N-chloro-species (43) is a white solid, soluble in pentane but explosively hydrolysed by water. The second product, (44), results when BrN(SiMe,), is used; formation of neither the bromo- analogue of (43) nor the analogous NN-dibromide was observed. 180 The novel borazine (45) has been prepared by the reaction of excess BBr, with Cl,VNCl. It can be characterized by its spectra.181 Ion-molecule reactions of N-trimethylborazine and borazine in H2, He, Ne, CH4, and Kr have been observed, following photon impact with 10.2eV radia- tion. Borazine produces chiefly the borazinium ion H3B3N3&+, which in turn reacts to give H,B,N,Hi. For N-trimethylborazine the only process detected is protonation from H3B3N3Me: to yield H,B,N,HMe;, where the transferred proton originates from the exocyclic methyl group.182 Non-empirical, minimal-basis-set calculations of the geometric and electronic structures of cyclotriborazane, (BH2NH2)3, indicate the preferred conformation to be the 'eclipsed boat' form. It has also been predicted to be thermodynamically unstable with respect to disproporti~nation.'~~ The compounds (46) and (47), where R2,R3 = H, Me, or Ph, may be prepared 0, H0 R l d 7 p-c / / O R'B A (46) (47) from R'BX, (X = halogen) and a-hydroxycarboxylic acids. They form adducts with a number of bases. Mass spectral fragmentation data were reported and 179 K. E. Blick, E. B. Bradley, K. Iwatani, K. Niedenzu, T. Rakusaka, T. Totani, and H. Watanabe, Z. anorg. Chem., 1975, 417, 19. G. Elter, H.-J. Kulps, and 0. Glemser, Angew. Chem. Internat. Edn., 1975, 14, 709. K. Dehnicke and V. Fernandez, Chem. Ber., 1976, 109, 488. R. H. Findlay, J.C.S. Dalton, 1976, 851. P. Paetzold, P. Bohm, A. Richter, and E. Scholl, 2. Natwrforsch., 1976, 31b, 754. 180 lS2 A. DeStefano and R. F. Porter, Inorg. Chem., 1975, 14, 2882. Elements of Group III 87 Mass spectral data have also been presented for a large number of fluoro- and phenyl-boron chelates, e.g. (48), where R = F, Ph, etc.lS5 The crystal structure of (salicyla1dehydato)diphenylboron (49) has been deter- mined. The B02C3 ring adopts an unusual conformation, described as being that of a ‘distorted sofa’.186 The compounds (SO), where X=Ph, SR, NR2, or NHR, have been described (49) for the first time. They are prepared as shown in Scheme 2, and their properties have been described.*” BSEt CH20H c H2- - 0, I + B(SEt), - I CH2-S’ CH2SH Scheme 2 3-Iodo-4-di-iodoborylhex-3-ene reacts with tri-iodoborthiin to give the di-iodo- derivative of 1,2,5-thiadiborolen (51)’ by a redox process.188 The crystal structure of this compound was determined, showing that the five-membered ring is very close to being planar. The two B-S distances are different, 1.83(2) and 1.94(2) A, due to intermolecular interactions between the two molecules in the 2,S-Dimethyl-3,4-diethyl-1,2,S-thiadiborolen reacts with Ni(C0)4 to give a complex with Ni(C0)2 present. This in turn decomposes to give (52). This is the unit ce11.189 Me I Ni (52) first known nickel-thiaborane complex to be thermally stable. The structure shown was confirmed by a single-crystal X-ray analysis.1Qo E. Hohaus and W. Riepe, Z. Naturforsch., 1976, 31b, 324. lS6 S. J. Rettig and J. Trotter, Canad. J. Chem., 1976, 54, 1168. lS7 R. H. Gragg, J. Dudman, and J. P. N. Husband, J. Organometallic Chem., 1976, 116, 281. W. Siebert, R. Full, T. Renk, and A. Ospici, Z. anorg. Chem., 1975, 418, 273. lS9 F. Zettler, H. Hess, W. Siebert, and R. Full, Z. anorg. Chem., 1976, 420, 285. 190 W. Siebert, R. Full, C. Krueger, and Y.-H. Tsay, Z. Naturforsch., 1976, 31b, 203. 88 Inorganic Chemistry of the Main-Group Elements Pariser-Pople-Parr-type LCI-SCF-M.O. calculations have been carried out on 4H-borepino[3,2-b : 6,7-b’]dithiophen (53). The results were used to rationalize the observed behaviour of some known derivatives of this.’” The dimethyl(thiophosphory1)amino-boranes [Me,P(S)-NR],B and [Me,P(S)- NRI2BX are monomeric. The dihalogeno-analogues Me,P(S)-NR-BX,, where X=F, C1, or Br, exist in solution as equilibrium mixtures of monomers and dimers, although Cl,P(S)NMe-BX,, where X = Br or Me, do not associate. “B n.m.r. spectra are consistent with S+B and not N+B co-ordination in the monomers, i.e. they may be formulated as (54).19, (53) (54) Boron Nitride, Metal Borides, etc.-U.v. and e.s.r. spectra of B2 trapped in an argon matrix at 10K are consistent with the ground state being “C,. This compares with the ground state ’I;, which is favoured by ab initio calculations.193 a-Rhombohedra1 boron reacts with N2 in the temperature range 1479-1823 K via a topochemical reaction, to give BN as a final product. If P-B is used as starting material, a two-stage reaction occurs with N,: a homogeneous reaction to form B6N, followed by a topochemical process giving BN,’94 The anisotropy of the X-ray emission bands for BN crystals can be used to separate these into u- and rr-components. The width of the rr-band was found to be 7.0 eV, while that of the a-band was 11.7 eV. As there is an overlap between the bands of 6.8eV, this corresponds to a total width for the valence band of 12.9eV. All of these results were rather similar to those for graphite.’”’ The boron-rich boron arsenide B12(A~1.77B0 23) is rhombohedral, belonging to the space group R3m. The structure is related to those of B12P2 and a-rhombo- hedral boron. 196 X-Ray data on a boron-rich titanium boride (E. Amberger and K. Polborn, Acta Cryst., 1975, B31,942) have been re-interpreted by Ploog as suggesting that the 2(b) positions are occupied by C and not by B atoms; this is said to lead to a stabilization of the tetrahedral arrangement of the B12 i ~0sahedra.l ~~ A further paper by the original authors, however, denies that C atoms can be present in this structure. 19* (B12)4B2V1.53 is tetragonal, belonging to the space group P4,lnnm. The cell constants of the non-stoicheiometric phases (B12)4B2V1.5--1 .9 do not depend sig- nificantly on the V ~0ntent.I ”~ A. T. Jefferies and C. Parkanyi, J. Phys. Chem., 1976, 80, 287. 192 G. Muckle, H. Noth, and W. Storch, Chem. Ber., 1976, 109, 2572. 193 W. R. M. Graham and W. Weitner, J. Chem. Phys., 1976, 65, 1516. 191 J. B. Condon, C. E. Holcombe, D. H. Johnson, and L. M. Steckel, Inorg. Chem., 1976, 15, 2173. C. Beyreuther, R. Hierl, and G. Wiech, Ber. Bunsengesellschaft. phys. Chem., 1975, 79, 108. 196 E. Amberger and P. A. Rauh, Acta Cryst., 1976, B32, 972. K. Ploog, Acta Cryst., 1976, B32, 981. E. Amberger and K. Polborn, Acta Cryst., 1976, B32, 1298. 194 195 197 199 E. Amberger and K. Polborn, Acta Cryst., 1976, $332, 974. Elements of Group III 89 The following species have all been detected in the Li-Ni-B system; LiNiB (rhombic), Li,Ni,,B,, (tetragonal), and Li,Ni,,B6 (cubic).200 The boride carbides MB,C have been identified and characterized for the lanthanides (M) from Tb to Lu.,O1 The species (CO,B),~R~H~ and (Ni,B),,RhH,, have been prepared by the reaction of ethanolic MC1, (M = Co or Ni) with RhC1,,3H20 and excess NaBH,. They are active catalysts for the processes of hydrogenation, hydrogenolysis, and me thanation .,02 2 Aluminium General.-The crystal structure of hexagonal Ba,Al, has been determined. The structures of this and of the previously determined Ba,Al,, were related to that of the Laves phase MgNi2.,03 SrAl possesses cubic symmetry, and is of space group P213. The structure is similar to that of cubic InC1. SrGa is isostructural with SrAL204 Aluminium Hydrides.-Ab initio M.O. calculations on hydroxyalane, H,Al(OH), show that there is a partial r-interaction in the Al-0 bond for the planar form of the molecule. This gives a calculated barrier to rotation about Al-0 of 4.35 kcal mol-', of the same type as in analogous boron Six crystalline phases of non-solvated AlH, can be produced by the desolvation of aluminium hydride etherate in the presence of small quantities of LiAlH,. The most stable form, a-AlH,, is produced from the solid metastable phases, or by recrystallization from a refluxing mixture of C6H6 and Et20.206 Methylaluminium tetrahydroborates Al(BH,),Me and Al(BH,)Me, can be pre- pared from AlMe, and A1(BH4),, in the molar ratios of 1 : 2 and 2 : 1, respectively, and also from AlMe,Cl,-, +(3- n)LiBH,, where n = 1 or 2. They are volatile, inflammable in air, and they vaporize as monomers. They also form the adducts Al(BH,),Me,L, where L=NMe,, NMe2H, PMe,, AsMe,, OMe,, OEt,, or SMe,, and Al(BH,)Me,,L, where L = NMe,, PMe,, or OEt2.207 Methods of preparation have been devised for the N-alkyl-iminoalanes (BdNAlH),, (Bu'NAlD),, (PiNMH),, (EtNAlH),, and (MeNAlH),. A number of intermediates, e. g. Al,H,(NBut),(NButNH),, were also isolated. The polymeric species generally have rather symmetrical structures, e.g. (55; R = H/D exhange in tetrameric N-alkyl-iminoalanes produces statistical mixtures H,-,D, (AlNCMe,),. H/Cl exchange in these and related compounds takes place without any exchange of alkyl groups, proving that redistribution of substituents 2oo W. Jung, Natunuiss., 1976, 63, 246. 201 J. Bauer and J. Debuigne, J. Inorg. Nuclear Chem., 1975, 37, 2473. ' 02 R. W. Mitchell, L. J. Pandolfi, and P. C. Maybury, J.C.S. Chem. Comm., 1976, 172. '03 M. L. Fornasini, Acta Cryst., 1975, B31, 2551. 204 M. L. Fornasini and F. Merlo, Acta Cryst., 1976, B32, 1864. 205 0. Gropen and E. W. Nilssen, J. Organometallic Chem., 1976, 111, 257. 206 F. M. Brower, N. E. Matzek, P. F. Reigler, H. W. Rinn, C. B. Roberts, D. L. Schmidt, J. A. Snover, 207 P. R. Oddy and M. G. H. Wallbridge, J.C.S. Dalton, 1976, 869. 208 H. Noth and P. Wolfgardt, Z. Natwrforsch., 1976, 31b, 697. and K. Terada, J. Amer. #em. SOC., 1976, 98, 2450. 90 Inorganic Chemistry of the Main-Group Elements (55) on the A1takes place without any XAlNR units being transferred by an exopoly- hedral exchange mechanism with five-co-ordinate Al.209 Another group of workers have reported a number of chlorination reactions of poly(N-alkyl-iminoalanes), e. g. (HAlNBu'),, (HAlNPi),, (HAlNPi),, using HCl, HgC12, or TiC1,. Several partly or wholly chlorinated products were isolated as pure, crystalline materials, e.g. (ClAlNBu'),, (ClAlNPi),, and (C1AlNPi)6.210 Poly(N-alkyl-iminoalanes) can be produced directly from A1 metal and a primary amine under an atmosphere of H2 at high pressures, e.g. the hexamers (HAlNR),, where R =PI!, Bus, or cyclohexyl, and the octamers (HAlNR),, where R=PP etc.211 Compounds containing AI-C Bonds.-The 27Al-13C coupling constants in di- meric AlMe, and its derivatives show remarkable similarities to "B-lH coupling constants in diborane derivatives. This arises from the similarity in the electronic structures of the two series, and can be accounted for by the Fermi-contact mechanism for spin-spin coupling.212 13C n.m.r. data have been reported for the compounds (AlEt,C13--x)2, where x = 1, 1.5, 2, or 3. Exchange reactions involving terminal Et and Cl groups were monitored in the compound with x = 1.5, and the energy of activation was ~alculated.~ l3 M(q-CsHs)2R2A12R2 (where R=Me, M=Sc, Gd, Dy, Ho, Er, Tm, or Yb; R = Et, M = Sc or Y) contain double alkyl bridges (56). They are prepared from (56) [M(q -C,H,),Cl], and Li Al k in toluene. Single-crystal X-ray structural determi- nations were carried out on the Y and Yb '09 H. Noth and P. Wolfgardt, 2. Nufurforsch., 1976, 31b, 1201. 'lo S. Cucinella, T. Salvatori, C. Busetto, and A. Mazzei, J. Orgunornetullic Chem., 1976, 108, 13. S. Cucinella, G. Dozzi, C. Busetto, and A. Mazzei, J. Organometullic Chem., 1976, 113, 233. 0. Yamamoto, J. Chem. Phys., 1975, 63, 2988. 212 '13 R. Rottler, C. G. Kreiter, and G. Fink, 2. Nuturforsch., 1976, 31b, 730. 214 J. Holton, M. F. Lappert, G. R. Scollary, D. G. H. Ballard, R. Pearce, J. L. Atwood, and W. E. Hunter, J.C.S. Chem. Comm., 1976, 425. Elements of Group III 91 Di( p- trans -t-butylvinyl) (tetraisobuty1)dialuinium contains bridging vinyl groups, with A1-C distances equal to 2.11 A, and a centrosymmetric A12C2 A unique type of bridging cyclopentadienyl group has been revealed by single-crystal X-ray diffraction on the ferrocenylalane dimer [(q-CsH,)Fe(q- C5H,)Al2Me3C1I2. The skeletal structure may be drawn schematically as (57).216 ,'q ,,Me Cl-AI-C \ Me, I C-A1' Me Me Aluminium-containing cyanoruthenates Al,[Ru(cN),], and KAl[Ru(CH),],- 5H20 may be prepared by simply mixing solutions of A1Cl3 and K,[Ru(CN),] in appropriate molar ratios.217 Compounds containing Al-N Bonds.-Reaction of M[Al(BH,),] (M = K or NBu,) with excess NH, yields MBH, and [Al(NH,)6](BH&2'8 The compound (MeAlNMe), forms monoclinic crystals, of space group P2,lc. The skeletal structure (58) is a cage that is of C,, symmetry. Each A1 and N atom is four-co-ordinate, and attached to three cage atoms and the C of a methyl group.219 The first neutral organo-aluminium-nitrogen compound containing four-co- ordinate Al, uiz. (59), has been prepared, by allowing AlMe, to react with H(Et)NC2H4NMe2 at 100°C. The monomeric form is present in aromatic sol- vents, but in aliphatic solvents dimerization occurs, with the formation of a linking unit (60).'" 'Is M. J. Albright, W. M. Butler, T. J. Anderson, M. D. Glick, and J. P. Oliver, J. Amer. Chem. SOC., 216 J. L. Atwood and A. L. Shoemaker, J.C.S. Chem. Comm., 1976, 536. '" L. I. Pavlenko, A. A. Gundorina, and A. N. Sergeeva, Russ. J. Inorg. Chem., 1975, 20, 576. "* K. N. Semenenko, I. I. Korobov, 0. V. Kravchenko, and S. P. Shilkin, Russ. J. Inorg. Chem., 1975, '19 P. B. Hitchcock, J. D. Smith, and K. M. Thomas, J.C.S. Dalton, 1976, 1433. 220 0. T. Beachley and K. C. Racette, Inorg. Chem., 1975, 14, 2534. 1976,. 98, 3995. 20, 1568. 92 Inorganic Chemistry of the Main -Group Elements A study of the complexation behaviour of Al”’ with Arsenazo I11 suggests that (61) is formed.221 H 0 2 I [AI(OP*),L reacts with ethylenediamine in benzene solution to form a number of species. *H, 13C, and ”A1 n.m.r. data indicate the skeletal structure (62) for one of these. Another is polymeric, but other, unidentified species are probably also present. There was no evidence for the presence of five-co-ordinate A1 in any of these, however.”’ Compounds containing 4-0 or Al-Se Bonds.-The thermodynamic charac- teristics of AlOCl and GaOCl vapours have been elucidated by measuring the temperature dependence of the vapour pressures of the dimeric and monomeric forms .223 The new adducts D,A1[OCH(CF3)2]3: where D=OEt,, NEt,, or PEt,, have been characterized, and their ‘H n.m.r. parameters determined.224 Knowing the positions of the hydrogen atoms in gibbsite, Al(OH),, from an accurate X-ray measurement, it is possible to calculate the most likely orienta- tions of hydroxy-groups in the bayerite form of Al(OH),.225 The Raman and far4.r. spectra of single crystals of alum have been recorded. All 221 V. Michaylova, J. Inorg. Nuclear Chern., 1975, 37, 2317. 222 J. W. Akitt and R. H. Duncan, J.C.S. Dalton, 1976, 1119. 223 A. I. Morozov and E. V. Maksyukova, Russ. J. Inorg. Chem., 1975, 20, 659. 224 J.-P. Laussac and J.-P. Laurent, J. Inorg. Nuclear Chem., 1976, 38, 597. 22s R. F. Giese, Acta Cr y s t . , 1976, B32, 1719. Elements of Group III 93 of the SO:- and Al(H,O);' inner vibrations could be assigned to modes of A,, E,, and T, symmetry of the factor group, while the lattice modes could also be assigned in terms of the factor group Th.2263227 Complex formation between AlBr, and sulphoxides has been investigated by dipole-moment and calorimetric measurements, and by i.r. spectroscopy.228 Stopped-flow pulse F.T. n.m.r. measurements have been used to monitor the exchange reaction (16), where DMSO = dimethyl sulphoxide and DMSO" = [2HJdimethyl sul pho~i de.~~~ Al(DMSO):+ +6DMSO* + Al(DMSO*):+ +6DMSO (16) Raman spectra of mixtures of AlEt,Cl and DMSO show that, in a 1 : 1 mixture, AlEt,Cl,DMSO is present. In the presence of excess DMSO, the complexes AlEt,,DMSO and AlC13(DMS0)6 are both present. Analogous mixtures of AlEtC1, and DMSO were found to be of very complicated compo~i ti ons.~~~ The solvation of Al"' in H,O-DMSO-acetone solvent systems has been studied by 'H n.m.r. There is no solvation by the acetone, although the H20 and DMSO are competitors for the cation co-ordination. The temperature dependence of co-ordination numbers, and the distribution of co-ordination numbers of the H20 and DMSO molecules at a mole ratio DMSO:H,OS0.8, suggest a solvation model in which the transfer of a solvent molecule in or out of the solvation shell involves no significant change in free energy.231 Reasonably stable 1 : 2 adducts of a number of carbonyl compounds PhCO,Me, EtCO,Me, and PhCOMe are formed with chloroaluminium compounds R,A1C13-,, usually in equilibrium with 1 : 1 species.232 N.q.r. and i.r. investigations of the adducts L,MX, have been reported, where L = benzophenones, benzoyl chlorides, or 4-chlorophenol; MX, = AlCl,, AlBr,, or GaCl,. The n.q.r. spectra (35C1 or 79Br) suggest that the benzoyl chlorides are weaker donors than the benzophenones. The shifts in u(C=O) observed in the i r., however, were the opposite way The equilibrium constant for the formation of the cation Al,(OH);+ is 10-7.42 when the ionic strength is 0.06.234 RbAlC14 and excess N205 react, in HNO, solution, to give Rb[Al(NO,),] and Rb,[Al(NO,),]. The latter also results from the reaction of AlBr, with a solution of RbNO, and N,O, in HN0,.235 Complexes A1L2+, where HL = formic, acetic, propionic, or butyric acid, are formed in an acidic medium. Their stability constants are 23, 32, 49, and 38, respectively. 236 226 H. H. Eysel and J. Eckert, Z. anorg. Chem., 1976, 424, 68. 227 J. Eckert, H. H. Eysel, and G. L. Kampfmeyer, Z. anorg. Chem., 1976, 424, 81. 228 V. V. Puchkova and E. N. Gur'yanova, J. Gen. Chem. (U.S.S.R.), 1975, 45, 949. 229 A. J. Brown, D. A. Couch, 0. W. Howarth, and P. Moore, J. Magn. Resonance, 1976, 21, 503. 230 J. Meunier and M. T. Forel, Bull. SOC. chim. France, 1975, 2465. 231 H. Chi, C.-H. Ng, and N. C. Li, J. Inorg. Nuclear Chem., 1976, 38, 529. 232 K. B. Starowieyski, S. Pasynkiewicz, and A. Sporzidski, J. Organometallic Chem., 1976, 117, 117. 233 T. Deeg and A. Weiss, Ber. Bunsengesellschaft. phys. Chem., 1976, 80, 2. 234 R. C. Turner, Canad. J. Chem., 1975, 53, 2811. 235 G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1975, 20, 856. 236 A. S. Kereichuk and L. M. Il'icheva, Russ. J. Inorg. Chem., 1975, 20, 1291. 94 Inorganic Chemistry of the Main- Group Elements Al"', Ga"', and Inrn catalyse the aquation reaction of malonatopenta-ammine- cobalt(II1). The kinetic data may be rationalized in terms of the reaction sequence (17) and ( 18)237 (NH,),CO(CO,CH,CO,H)~+ + M3+ (NH,),Co(C0,CH2C02)M4' + H+ (17) (NH,)5Co(C0,CH,C0,)M4+ + H,O + (NH3)5Co(0H,)3++ CH,(CO,),M+ (18) Yields of 14% of Al(acac), were obtained by a new general technique for the preparation of metal acetylacetonates by direct reaction of Hacac with metal atoms.238 Al(acac), has been resolved into its optical isomers in high yield by chromatog- raphy on ~-lactose-&O~ at 210K. The absolute configuration of that enan- tiomer having positive circular dichroism at 303 nm was established as y-Tris(pentane-2,4-dionato)aluminium(111) has an almost identical molecular structure to the a-form. The differences lie chiefly in the orientations of the Studies of the kinetics and steric course of the first-order intramolecular stereoisomerizations of the Al"' P-diketonates tris(2,6-dimethylheptane-3,5- dionato(aluminium(II1) and bis( 1,1,1,5,5,5-hexafluoropentane-2,4-dionato)alu- minium(II1) have been made. It appears that chelates having alkyl or aryl substituents on the P-diketonate rings isomerize by a rhombic twist mechanism. If fluorocarbon substituents are present, however, a bond-rupture mechanism is more likely, with formation of a square-pyramidal apical five-co-ordinate inter- mediate .241 'H n.m.r. spectra of tetraethylalumoxane suggest that the Et groups are bridging, and the structure (63) has been proposed. Thus, it is trimeric '(Et,Al),O' in benzene Raman spectroscopic investigations of A1203 dissolved in molten cryolite reveal that the only v(Al-0) features observed are at less than 600 cm-'. This rules out "' A. C. Dash and R. K. Nanda, J. Inorg. Nuclear Chem., 1975, 37, 2139. 238 J. R. Blackborow, C. R. Eady, E. A. Korner von Gustorf, A. Scrivanti, and 0. Wolfbeis, J. 239 B. NordCn and I. JonlS, Inorg. Nuclear Chem. Letters, 1976, 12, 33. 240 B. W. McClelland, Acta Cryst., 1975, B31, 2496. 241 M. Pickering, B. Jurado, and C. S. Springer, J. Amer. Chem. Soc., 1976, 98, 4503. 242 M. Boleslawski, S. Pasynkiewicz, A. Kunicki, and J. Serwatowski, J. Organometallic Chem., 1976, Organometallic Chem., 1976, 108, C32. 116, 285. Elements of Group III 95 the presence of any species involving non-bridging A1-0 bonds, although the exact nature of the species present could not be defined.243 8-A1203 is much more reactive than S - A1 2 0 3 in the formation of ZnAl,O,, due to the larger specific surface area of the former.244 X-Ray data on CaA1,0, have been refined to give information about the orientation of the tetrahedral units.245 A preliminary notification has been given of the existence of a new, high- temperature phase of andalusite, A12Si05 .246 A formamide intercalation adduct of dickite, Al,Si,O,(OH),, is the first clay- mineral intercalate that has been shown to possess an ordered structure of interlamellar molecules. Thus, the formamide molecules lie over vacant octa- hedral sites in the aluminosilicate layers.247 The rare zeolite edingtonite, B2.02A14,03Si5~97020,7.81H20, is orthorhombic, of space group P212121. The Si-Al ordering is similar to that found in natr01ite.~~~ The synthetic zeolite K-F, K13(OH)3(H,0),3SiloAllo040, has a tetragonal primi- tive cell, with the probable space group Ccc2. The structure appears to be related to that of edi ngt~ni te.~~~ Direct microscopy shows that crystals of zeolites are sometimes formed from sodium aluminosilicate solutions at 70 "C without intermediate gel formation. When a gel is formed, it acts as a reservoir of reagent, and nucleation is favoured by the presence of zeolite An orthorhombic modification of Sr[Al,Ge,O,] has been characterized; it belongs to the space group F~i dd. ~~' Partial reduction (using H,) of mixtures of A1203, TiO,, and Nb205 gives non- stoicheiometric aluminium ni oboti tanate~.~~~ The following tungstoaluminosilicates were isolated from mixtures of aluminium nitrate and potassium 1 1-tungstosilicate: M5[SiAlW11039,H20],nHz0, where M = H or Na,n = 14; M = K, n = 12; and M = Cs, n = Aluminium tungstosilicate, AlH[Si(W3Olo),],18H,O, has been isolated. I t de- composes, at about 9OO"C, as shown in reaction (19).254 AlH[Si(W3010)4],18H,0 + o.5A2O +SiO, + 12W03 + 18.5H20 (19) A number of mixed tungstates of Al and Ga with K, Rb, or Cs have been isolated; they have the general formula MJx (McW2.-x)06, where M = K, Rb, or Cs; M' = Al or Ga; 0.1 1 s x S 0.22. When M = K, M' = Al, there is evidence for the stoicheiometric KAl(W04), at high temperature^.^^^ 243 B. Gilbert, G. Mamantov, and G. M. Begun, Inorg. Nuclear Chem. Letters, 1976, 12, 415. 244 T. Tsuchida, R. Furuichi, and T. Ishii, Z. anorg. Chem., 1976, 423, 180. 245 W. Horkner and H. Muller-Buschbaum, J. fnorg. Nuclear Chem., 1976, 38, 983. 246 H. Schneider and W. Pannhorst, Nuturwiss., 1976, 63, 37. 247 J. M. Adams and D. A. Jefferson, Acta Cryst., 1976, B32, 1180. 248 E. Galli, Actu Cr yst ., 1976, B32, 1623. 249 E. Tambuyzer and H. J. Bosmans, Acta Cryst., 1976, B32, 1714. J.-L. Guth, P. Caullet, and B. Wey, Bull, Soc. chim. France, 1975, 2375. H. Pentinghaus and H. Krol, Natunviss., 1975, 62, 485. 252 V. G. Teplov, G. G. Kasimov, and A. U. Ospanov, Russ. J. Inorg. Chem., 1975, 20, 1266. V. I. Spitsyn, I. D. Kolli, and T. A. Bogatyreva, Russ. J. Inorg. Chem., 1975, 20, 1255. 254 V. E. Plyushchev, N. P. Krauzoldt, E. S. Razgon, and V. M. Amosov, Russ. J. Inorg. Chem., 1975, 20, 1252. 255 P. V. Klevtsov and V. A. Sinaiko, Russ. J. Inorg. Chem., 1975, 20, 1170. 253 96 Inorganic Chemistry of the Main-Group Elements Single crystals of Sr0,3.5Fe,0,,2.5A120, have been prepared and studied by X-ray difiaction. The atomic distribution is different from that in other magneto- plumbite Al(Po3)3 is monoclinic, and belongs to the space group Ic. The structure is built up from AlO, octahedra and PO, tetrahedra, so that there are infinite chains of PO, units along [OOl], with these being interconnected by the octahedra. The r( Al - 0) distance in the AlO, fragment is 1.884A (mean).257 The salt A15(P3010)3,24H20 may be isolated from the systems Na,P301,- AlC1,-H, 0 or Na, P3 0 ,-Al(NO,) 3-H2 0. 258 Al,(OH),TeO,SO, is built up of tetrahedral SO:- anions and pyramidal TeO, units, linked by the A1atoms to form infinite sheets. The co-ordination of the A1 is approximately octahedral, and the A1-0 distances fall in the range 1.864- Al, Ga, and In chlorides form complex tellurates 2K20,M203,4Te03,nH,0 in the MC1,-H6Te0,-KOH-H2O systems.26o The A1compound, with n = 10, separates from the AlC1,-K,H2Te06-H20 System .261 If AlCl, or Al(ClO,), solutions are partially neutralized, very slowly, using NH3 or finely ground dolomite as the base, stable polynuclear hydroxyaluminium cations are formed. These do not deposit solids over periods of up to 2 years. It seems, however, that a second type of cation, with the same 0H:Al ratio as the first, but less reactive, is formed on ageing.,,, The energy of activation for the conversion of the first into the second type of polycation is 20.8 kcal mol-l. No suggestions were made as to the structures of these species, however.,,, The crystal structure of K[MeSe(lUMe3)3],2c6& has been determined. The Se is tetrahedrally co-ordinated, and the average AI-Se bond length is 2.578(5) A.264 Aluminium Halides.-The enthalpies and entropies of formation of AlF2', Al g, and AlF, have been calculated from measurements on aqueous solutions of Al(ClO,), containing NaF, at 25 "C, and I = 0.5 (Table l).,,, 1.934 A.2s9 Table 1 Enthalpies and entropies of formation of A1F2', Alg, and A1F3 Complex -AGlkcal mol-' AS/cal mol-' K-' Alp' 8.38 f 0.04 30.25 f 0.21 AlF, 20.68 f 0.27 73.6 k1.4 AlFl 15.32 f 0.14 55.27*0.6 Phase diagrams have been constructed for the following systems: Li3A1F6-LiCl- LiF, 3Li,3Na 11AlF6,3F, and 3Li,3Na I( AlF6,3C1.266 H. Pausch and H. Muller-Buschbaum, 2. Narurforsch., 1976, 31b, 1148. H. van der Meer, Acta Cr yst ., 1976, B32, 2423. V. A. Lyutsko, N. F. Ermolenko, and L. I. Prodan, Russ. J. Inorg. Chem., 1975, 20, 792. G. B. Johansson and 0. Lindqvist, Acra Cr yst ., 1976, B32, 407. N. K. Bol'shakova and A. A. Kudinova, Russ. J. Inorg. Chem., 1975, 20, 675. N. K. Bol'shakova and A. A. Kudinova, Russ. J. Inorg. Chem., 1975, 20, 960. 256 257 258 259 260 261 262 R. C. Turner, Canad. J. Chem., 1976, 54, 1528. 263 R. C. Turner, Canad. J. Chem., 1976, 54, 1910. J. L. Atwood and S. K. Seale, J. Organomerallic Chem., 1976, 114, 107. V. P. Vasil'ev and E. V. Kozlovskii, Russ. J. Inorg. Chem., 1975, 20, 672. V. I. Vereschagina, K. V. Gontar', and L. V. Zolotareva, Russ. J. Inorg. Chem., 1975, 20, 930. 264 265 266 Elements of Group III 97 Hexagonal-rhombohedra1 modifications of the elpasolites M2M'A1F6 (M = Rb, M'=Li; M=Cs, M'=Na) can be converted into cubic forms at high pressures (15-100 kbar), in some cases via the hexagonal forms analogous to K2LiAlF6.267 Fifteen new hexafluoroaluminates(m), of the elpasolite type, have been ob- tained by heating mixtures of the binary fluorides.268 An i.r. band due to A13,Cl is seen at 470 cm-' in a Ne matrix, and at 455 cn--' in an Ar matrix. The 35C1/37C1 isotopic shift in the Ar matrix is 5.4* 0.2 cm-l. AlBr gives bands at 370, 357, and 349cm-', respectively, in Ne, Ar, and N2 matrices. The 81Br/79Br isotope shift is 0.95 *0.2 cm-' in Ar. The fundamental band due to v, of monomeric AlBr, is at 508.4crr-' in an Ar matrix.269 A single-crystal X-ray study shows that 'A1Cl3,2MeCN' is in fact ionic: [AlCl(MeCN),~'[AlCl~]2,MeCN. One of the MeCN molecules is present as a molecule of sol ~ati on.~~* Alcoholates of AlCl,, i.e. AlC1,,3ROH, react with cyclopentadiene or NaC,H, to produce (C5H,)A1C1,,3ROH, where R=Me, Et, Pr", Pr', Bun, Bui, or i- C,H,, .271 The controversy on the structure of monomeric AlCl, now seems to have been resolved in favour of a planar This is consistent with the latest data on i.r. and Raman spectra of the matrix-isolated AlCl,. These data, together with those on monomeric GaCl, and InCl, in Ar matrices at low temperatures, have been fully reported. The assignments were supported by high-resolution studies to identify the intensity patterns of vibrations due to the isotopic variants. All obey the selection rules for planar, D3h, symmetry. Thus the earlier assignments for AlCl,, based upon a model with C,, symmetry, were shown to be erroneous.274 In yet another paper there is a report of the i.r. spectra of matrix-isolated AlCl,, together with data on Al2Cl+Force constants of the general valence force field for AlCl, were calculated, using 3'C1/37C1 shifts, and data from vapour-phase rneasurernent~.~~~ Formation of adducts by AlCl, with arene or cyclopentadienyl metal carbonyls can take place either at Co, to give (64), or at the metal, giving (65), where L,L' = PPh, or CO; n = 1 or 2; M =various transition metals. The use of benzene 267 J. Arndt, D. Babel, R. Haegele, and N. Rombach, Z. anorg. Chem., 1975, 418, 193. 268 J. Setter and R. Hoppe, 2. anorg. Chem., 1976, 423, 133. 269 Hg. Schnockel, 2. Nafurforsch., 1976, 31b, 1291. 270 J. A. K. Howard, L. E. Smart, and C. J. Gilmore, J.C.S. Chem. Comm., 1976, 477. 271 S. Mehra and R. K. Multani, J. Inorg. Nuclear Chem., 1975, 37, 2315. 272 I. R. Beattie, H. E. Blayden, and J. S. Ogden, J. Chem. Phys., 1976, 64, 909. 273 J. S. Shirk and A. E. Shirk, J. Chem. Phys., 1976, 64, 910. 274 I. R. Beattie, H. E. Blayden, S. M. Hall, S. N. Jenny, and J. S. Qgden, J.C.S. Dalton, 1976, 666. 275 Hg. Schnockel, Z. anorg. Chem., 1976, 424, 203. 98 Inorganic Chemistry of the Main - Group Elements as solvent, with L = L' = CO, favours formation of (65), while the use of CH2C12 as solvent favours (64). Replacement of L and L' by PPh, also favours (64), as does the replacement of ring H atoms by other ~ubsti tuents.~~~ The solubilities of MCl, (M=Al, Ga, or In) in tributyl phosphate are in the order Al<I n<Ga. The A1 and In compounds are probably present as MCl,,nTBP. Similar species are also present for Ga, and also [ GaCl,(TBP)J+[GaCl,]-, with mixed chloro( butoxyp hosp ha to) -complexes .277 (NO)AlCl, possesses a crystal structure of the BaSO, type. The AlC1; is a slightly distorted tetrahedron, with r(Al-Cl) in the range 2.104(3)- 2.125(2) A.278 Heats of formation, AH,(salt,c), lattice energies, and (first) bond dissociation energies have been measured for CsMC1, and CsMBr,, where M = A1 or Ga (Table 2). D(InC1,-Cl-) was estimated to be 98 f 10 kcal m01-l.~~' Table 2 Thermodynamic parameters for tetrahalogeno-aluminates and -gallates Compound AH,/kcal mol-l U/kcal mol-' Dlkcal mol-l csAlc1, -292.0 120 87*7 CsGaC1, - 252.0 119 87*7 CsAlBr, - 239.4 115 80*7 CsGaBr, - 203.4 116 75*7 Lattice energies and thermodynamic parameters have been calculated and tabulated for AlCl, and GaC1;.280 Thermodynamic characteristics of the NH,C1-NaAlCl, fused salt system have been derived from measurements of vapour pressures generated by such mixtures, as a function of temperature. At low mole fractions of NH4C1, and temperatures below 650 K, the chief component is HCl, with very little NH, or NH3,A1C1,.281 CuAlCl, has been shown to be present in the vapour over CuCl-AlC1, mixtures. The following thermodynamic parameters were elucidated:282 CuCl (s) +AlC1, (g) -+CuAIC1, (8); CuAlC1, (s) -+CuAlCl (g); AH*(640 K) = -0.8 kcal mol-l, AS0(640 K) = -2 cal mol-' K-' AH*(473 K) = 34 kcal mol-'; AS0(473 K) = 48 cal mol-l K-' The AlC1,-PCl, system exhibits a negative azeotrope, close to the composition AlCl,,PCl,. Considerable deviations were found in the molar volumes from those predicted by the additivity FeAlCl, is formed from either Fe/Al + CI2 or FeC1,-AlCl, mixtures. Mass spectral and i.r. results suggest that it is the structural analogue of the FeC1, and AlCl, di mer~.~~, B. V. Lokshin, E. B. Rusach, Z. P. Valueva, A. G. Ginzburg, and N. E. Kolobova, J. Organometallic Chem., 1975, 102, 535. Yu. M. Glubokov, S. S. Korovin, A. M. Reznik, M. R. Agevnin, and I. P. Romm, Russ. J. Znorg. Chem., 1975, 20, 1396. 276 277 278 P. Barbier, G. Mairesse, J. P. Wignacourt, and F. Baert, Cryst. Struct. Comm., 1976, 5,633. 279 R. C. Gearhart, J. D. Beck, and R. H. Wood, Znorg. Chem., 1975, 14, 2413. H. D. B. Jenkins, Inorg. Chem., 1976, 15, 241. W. C. Laughlin and N. W. Gregory, Inorg. Chem., 1975, 14, 2902. 282 W. C. Laughlin and N. W. Gregory, J. Phys. Chem., 1976, 80, 127. 283 Yu. N. Lyzlov, S. I. Solov'ev, and L. A. Nisel'son, Russ. J. Inorg. Chem., 1975, 20, 1233. 284 R. M. Fowler and S. S. Melford, Znorg. Chem., 1976, 15, 473. 280 Elements of Group III 99 The Raman spectrum of the species CUA12C18in the vapour phase shows that it has no centre of symmetry, and that the co-ordination number of the Cu does not exceed three. The most plausible structure suggested is the cyclic one (66).285 3 Gallium Compounds containing Ga-N, Ga-P, or Ga-As Bonds.-Electron-diffraction results on Cl,Ga,NH, yielded the following structural parameters: r(GaC1) 2.142 f 0.005, r(GaN) 2.057&0.011, r(C1. - * Cl) 3.642k0.010, and r(C1. * * N) 3.242* 0.012 A. The GaCl, fragment has a very flat pyramidal structure, consistent with a planar structure for free GaC1,. The donor-acceptor interaction is probably weaker than in the A1analogue.286 Gas-phase electron-diffraction results on Me,Ga,L, where L = NMe, or PMe,, gave the following values for the donor-acceptor bond: r(Ga-N) 2.20(3), r(Ga- P) 2.52(3) A.287 The crystal structure of GaMe,(Cl)(phen) shows that the molecular structure is (67). Only the Ga-N distances are affected by intramolecular ligand-ligand steric interactions. Determinations of molecular weight show that this structure is maintained in CHCl, solution, but that ionization occurs in water.288 Ga(NMe,),, CIGa(NMe,),, and Ga[N(SiMe,),], are made by the reaction of GaC1, with LiNMe, or NaN(SiMe,), respectively. Excess LiNMe, gives Li[Ga(NMe,),]. CS, inserts into all of the Ga-N bonds of Ga(NMe,),, forming Ga(S,CNMe,),. The trisdimethylaminogallane is dimeric, via NMe, bridges. 'H n.m.r. and i.r. data have been listed, as they were also for Al(NMe,), and ClAl(NMe,), .289 The molecular structures have been deduced (from X-ray data) for pyrazolyl-, 3-methylpyrazolyl-, and imidazolyl-gallium dimethyl dimers, (Me2GaN2C3H3)2, 285 F. P. Emmenegger, C. Rohrbasser, and C. W. Schlapfer, Inorg. Nuclear Chem. Letters, 1976,12, 127. M. Hargittai, I. Hargittai, and V. P. Spiridonov, J. Mol. Structure, 1976, 30, 31. L. M. Golubinskaya, A. V. Golubinskii, V. S. Mastryukov, L. V. Vilkov, and V. I. Bregadze, J. Orgunornetallic Chem., 1976, 117, C4. 286 287 288 A. T. McPhail, R. W. Miller, C. G. Pitt, G. Gupta, and S. G. Srivastava, J.C.S. Dalton, 1976, 1657. 289 H. Noth and P. Konrad, Z. Naturforsch., 1975, 30b, 681. 100 Inorganic Chemistry of the Main-Group Elements (Me,GaN,C,H,),, and (Me,GaN,C,H,),. Comparison with (D,GaN,C,H,), shows that replacing D by the Me groups leads to a pronounced flattening of the Ga- (N-N),-Ga 'boat', and a lengthening of the Ga-N A similar conclusion was drawn from structural studies on (Me2GaN2C5H,),, the dimer of 3,5-dimethylpyrazolylgallium dimethyl. Thus, the Ga-(N-N),-Ga unit is almost planar because of the steric interactions between Me groups. The related compound [Me,Ga(OH) (N,C5H,)GaMe,,2N,C,H,] contains a five- membered Ga,N,O ring.291 The species Ca,,Ga,N,,, Ca,Ga,N,, and CaGaN were detected in a study of the system Ca-Ga-N.292 Ca,Ga,As, is orthorhombic, belonging to the space group Pbam. The structure is built up of layers of Ca-As and Ga-As octahedra. The layers are linked by another Ca-As octahedron, heptaco-cordinate Ca2', and As-As pairs.293 Compounds containing Bonds Between Gallium and Atoms of Elements of Group V1.-Equilibrium constants have been measured for the complexes of Ga'" in aqueous solution, with 16 multidentate ligands of various types. The species formed depend upon the nature of L and the pH, but they could all be described as one of the general series Ga, (OH), H, Ld, where 1 < a < 3; 0 < b < 4 ; 0 < c < 3, and 1 < d < 3.294 Gallium(II1) forms complexes Ga(OH),(cit)"-, where n=0, 1, 2, or 3, in aqueous solutions of citric acid. All are polymerized to some extent; e.g. at a 1 : 1 molar ratio of citrate : Ga, and pH 2-2.6, Ga(OH),(cit)'- is largely in the form Ga,(oH),(~i t)~-.*~~ Both In3+and Ga3+form a series of complexes with tartaric acid (H,A). Their stability constants have been measured, and are listed in Table 3.296 Table 3 Stabilities of indium and gallium tartrates Complex : MA+ MA; M(HA); Log stability constants : 5.04 9.21 4.72 (In) 5.55 9.33 5.23 (Ga) Some 1 : 1 and 1 : 2 complexes of GalI1 with 3,4-dihydroxyazobenzene contain the ligand in the quinonehydrazone form (1 : l), or in the azo-form (1 : 2).297 MR, compounds, where M = Ga, In, or TI, R = Me; M = Ga, R = Et, react with HONMeCl(=O)Me to give dialkylmetal hydroxamates. I.r., Raman, and 'H n.m.r. spectra of these compounds could all be analysed in terms of monomeric structures (65) containing a five-membered ring.298 OaMe, reacts with diacetamide to give (69). 'H n.m.r. and some i.r. and Raman data (partly assigned) have been listed for this 290 D. F. Rendle, A. Storr, and J . Trotter, Canad. J. Chem., 1975, 53, 2930. 291 D. F. Rendle, A. Storr, and J . Trotter, Canad. J. Chem., 1975, 53, 2944. 292 P. Verdier, R. Marchand, and J . Lang, Rev. Chim. minerale, 1976, 13, 214. 294 W. R. Harris and A. E. Martell, Inorg. Chem., 1976, 15, 713. 295 F. Ya. Kul'ba, N. A. Babkina, and A. P. Zharkov, Russ. J. Inorg. Chem., 1975, 20, 1461. 296 G. E. Kodina, V. I. Levin, and V. S. Novoselov, Russ. J. Inorg. Chern., 1975, 20, 1140. 297 V. D. Salikhov, L. I. Gen', E. R. Oskotskaya, and M. Z. Yampolskii, Russ. J. Inorg. Chem., 1975,20, 298 H.-U. Schwering and I. Weidlein, J. Organometallic Chem., 1975, 99, 223. 299 B. Eberwein, F. Sille, and J . Weidlein, 2. Naturforsch., 1976, 31b, 689. P. Verdier, P. L'Haridon, M. Maunaye, and Y. Laurent, Actu Cryst., 1976, B32, 726. 293 1619. Elements of Group III 101 The crystal structure of salicylaldehydatogallium dimethyl dimer (70) has been determined. The Ga atoms are five-co-ordinate, with distorted trigonal- bipyramidal geometry. The Ga,O, ring is centrosymmetric.300 (68) (69) (70) The reaction of NH, with gallium double oxides gives no ternary compound formation. At low temperatures, however, two modifications of the new phase Ga1-x,30 x,3N1--r Ox, where x = 1, can be is~lated.~" Heating the appropriate mixture of Na,O and Ga203 under Ar for l day at 650°C produces the new gallate Na,Ga,O,. The crystal structure of this shows that the Ga207 units are effectively isolated.302 Hydrated lithium gallosilicate phases, e.g. 1.4Li,0,Ga20,,2.9Si0,,2.5H20, have been identified and characterized from the system Ga,03-Li,O-Si0,- The phase 2Ga,03,Sn0, is formed by heating the component mixture to 1300-1400 0C.304 Protonated complexes [GaHPO,]' and [GaH,P0,I2' are formed in the Ga3'- H,C,O,-H,PO, system. Their instability constants are 5.52 x lo-* and 3.28 X lop2, re~pectively.~'~ Ga,O, and Sb203 form a species GaSbO,, with a structure of the disordered rutile type. With In,O,, a phase of variable composition In,-,Sb,O,+x (x Q 1) is produced. This also has a rutile-type structure, with some monoclinic distortion when the Sb concentration is increased to give the composition InSb04.306 The structure of Ga4TiZ104* has been shown to possess elements related to the structure of P-Ga20,. Columns of this type are separated by hexagonal tun- nel ~. ~' ~ The phase diagram of Li0,5Ga2.504-C~Ga204 has been established.308 YGaO, is hexagonal, of space group P63cm, and isostructural with L uM~O,.~'~ The crystal structures of M(S,CNEt,),, where M = Ga or In, have been deter- mined. They are isostructural, monoclinic, and belong to the space group AZ/a. H,o.,O, 300 S. J. Rettig, A. Storr, and J. Trotter, Canad. J. Chem., 1976, 54, 1278. 301 P. Verdier and R. Marchand, Rev. Chim. minerale, 1976, 13, 145. 302 D. Fink and R. Hoppe, Z. anorg. Chem., 1976, 422, 1. N. P. Tomilov, T. I. Samsonova, A. S. Berger, and A. N. Kolyshev, Russ. J. Inorg. Chem., 1975, 20, 1549. 304 M. B. Varfolomeev, A. S. Mironova, T. I. Dudina, and N. D. Koldashov, Russ. J. Inorg. Chem., 1975, 20, 1738. 305 Yu. I. Mikhailyuk and V. I. Gordienko, Russ. J. Inorg. Chem., 1975, 20, 1617. 306 M. B. Varfolomeev, M. N. Sotnikova, F. Kh. Chibirova, and V. S. Shpinel', Russ. J. Inorg. Chem., 307 D. J. Lloyd, I. E. Grey, and L. A. Bursill, Acta Cr yst ., 1976, B32, 1756. 309 S. Geller, J. B. Jeffries, and P. J. Curlander, Acta Crysr., 1975, B31, 2770. 303 1975, 20, 655. J. Lopitaux, J. Arsene, and M. Lenglet, J. Inorg. Nuclear Chem., 1976, 38, 985. 308 102 Inorganic Chemistry of the Main-Group Elements The molecular structure is novel for tris-diethyldithiocarbamates; the three ligands are quasi-symmetric bidentate, with overall symmetry close to D3. The mean Ga-S distance is 2.436 A, while In-S is 2.597 A.310 N.q.r. coupling constants and asymmetry parameters have been measured for 69Ga and "'In in the following: Gas, GaSe, GaTe, Ins, InSe, a-Ga2S3, In203, p -In,S,, y-In$,, and In,Se,. Metal-chalcogen bonding of intermediate ionicity was indicated in every p-Gas is hexagonal, of space group P63lmmc. The layer structure differs from that of the 6-form in that the interlayer S-S distance is more than twice the van der Waal's Crystal structures have also been obtained for the related systems p- GaSo.59Seo.41313 and 6-GaSe.,14 All have layer structures, and the most important interatomic distances have been tabulated. MnGa,Se, and MnGa,Te can both be prepared by the direct reaction of the elements. They are tetragonal, of space group 14.~~' Gallium Halides.-The optimum conditions for the preparation of trialkylgallanes by the reaction (20), where R = Et, Pr", Bun, Bu', Bus, or But, are as follows: (i) use 3RLi + GaC1, 4 3LiC1 + R,Ga (20) reagents in c6- solutions in exactly 3 : 1 molar ratio, (ii) heat the mixture for 12 h at 70 "C, and (iii) filter off the LiC1, remove the solvent in vucuo, and then vacuum distil the R,Ga. Alternatively, RGaCl, and R,GaCl tire produced at the approp- riate molar ratios. If the ratio RLi : GaCl, is greater than 3, then some LiGaR, is produced. I.r., 'H n.m.r., and mass spectra of R,,GaCl,-, were all KGa,Cl, is orthorhombic, belonging to the space group Pna 21. Isolated Ga,Cl; ions are present. There is considerable similarity between the structure of these and of Cl,O,. The following structural parameters have been reported: r[Ga- Cl(termina1)l 2.13-2.15 A, r[Ga-Cl(bridge)] 2.33, 2.28 A, LGaCl,,Ga 108 .7°.3 l7 CoGa,Cl, is formed from CoCl, + Ga,CI,; Ap ( 6 7 3 K) = 43.9k 0.7 kJ mol-l, ASe(673 K) = 36.9* 1.1 J K-' mol-l. The structure is thought to be (71), rather (7 1) than one with a central Co atom. The cobalt co-ordination is almost certainly tetrahedral, and not octd~edral .~'~ K. Dymock, G. J. Palenik, J. Slezak, C. L. Raston, and A. H. White, J.C.S. Dalton, 1976, 28. T. J. Bastow and H. J. Whitfield, J. Magn. Resonance, 1975, 20, 1. 312 A. Kuhn, A. Chevy, and R. Chevalier, Acru Cryst., 1976, B32, 983. A. Kuhn, R. Chevalier, C. Desnoyers, and J. C. J. M. Terhell, Actu Cryst., 1976, B32, 1910. 314 A. Kuhn, R. Chevalier, and A. Rimsky, Acra Cryst., 1975, B31, 2841. 31s K.-J. Range and H.-J. Hiibner, 2. Naturforsch., 1976, 31b, 886. 316 R. A. Novak, H. Derr, D. Brandau, and J. 0. Callaway, Inorg. Chem., 1975,14, 2809. 317 D. Mascherpa-Corral, P. Vitse, A. Potier, and J. Darriet, Actu Cryst., 1976, B32, 247. 318 A. Anundskis, A. E. Mahgoub, and H. A. 0ye , Acta. Chem. Scund. (A), 1976, 30, 193. 310 311 313 Elements of Group III 103 C1n.q.r. spectra of (n-C,H9),N(GaClXBr4-,), where x = 0, 1, 2, or 3, show that they are individual compounds. The spectra also indicated that there was statistical disordering in the immediate neighbourhood of the resonance atom.319 N,O,-GaBr, and N,O,-GaBr,-MBr mixtures (M = Na or Li) undergo reaction to produce anhydrous Ga(N03), and M[Ga(NO,),], re~pectively.~~' Some new adducts of HMI, (M = Ga or In) have been prepared, containing two Et,O or four pyridine Raman and i.r. spectra of the Rb' and Cs' salts of Ga,I; show that the anion possesses D3d symmetry in the melt, and Ci symmetry in the crystal. The Ga-I-Ga unit is linear in both cases. A single crystal of CsGa,17 belongs to the space group Pb~m. ~~' 35 4 Indium General.-A number of thermodynamic parameters have been calculated for In3' in aqueous solution at 25°C. The standard ionic free energy, AGe, is -22.9 kcal mol-', and the enthalpy of formation, AH", is -57.8 kcal mol-'. A value was also obtained for the entropy of formation of InCl, (aq).323 A re-investigation of the Li-In system has revealed that it is more complex than was previously thought. Eleven new phases were detected, of which five were stable at room temperature: Li71n4, Li,In, Li81n3, Li,In, and A-Li,In. The remain- ing six were stable at higher temperatures: LiJn,, q-Li,31n27, LillIn4, K-LiJn, Li,In, and Li121n.324 Compounds containing Bonds Between Indium and Atoms of Elements of Group VI.-In3' ions are hydrolysed in H,O-acetone solutions at 25 "C to form chiefly monomeric products. 325 2-Formylpyrrole(C4H,NCHO) and 2-acetylpyrrole(C4H4NCOMe), = HL, react with In3+as neutral unidentate species to give InC1,,3HL, or, for L= 2-acetyl- pyrrolate only, as .a bidentate, anionic ligand, to give In&. The compounds Me,InL were also prepared and characterized, for both L.326 The crystal skucture of the complex of Inr1' with 1-(2-thenyl)-4,4,4-trifluoro- butane- 1,3-dione, In(tta),, has been determined. The metal atom is co-ordinated by six 0 atoms, forming a slightly distorted octahedron. The average In-0 distance is 2,13(2)A. The two C-C bonds in the P-diketonate ligand are of unequal length.327 Dimethylindium(m) acetate, Me,In(OAc), reacts with toluene-3,A- dithiol (H,tdt) with evolution of differing amounts of CH4, dependent on solvent conditions. It is thought that an intermediate dimer [MeIn(OAc) (Htdt)], is I. M. Alymov, T. L. Khotsyanova, E. V. Bryukhova, A. N. Grigor'ev, L. M. Mikheeva, and L. N. Komissarova, Russ. J. Inorg. Chem., 1975, 20, 1262. B. N. Ivanov-Emin, Z. K. Odinets, S. F. Yushchenko, B. E. Zaitsev, and A. I. Ezhov, Russ. J. Inorg. Chem., 1975, 20, 843. D. Mascherpa-Corral and A. Potier, J. Inorg. Nuclear Chem., 1976, 38, 211. 319 320 321 D. Kaminaris, J . Kouinis, and A. G. Galinos, J. Inorg. Nuclear Chem., 1976, 38, 344. 323 A. N. Campbell, Canad. J. Chem., 1976, 54, 703. 324 W. A. Alexander, L. D. Calvert, R. H. Gamble, and K. Schinzel, Canad. J. Chem., 1976,54,1052. F. Ya. Kul'ba, D. A. Zenchenko, and Yu. B. Yakovlev, Russ. J. Inorg. Chem., 1975, 20, 1314. 326 H, L. Chung and D. G. Tuck, Canad. J. Chem., 1975, 53, 3492. 327 H. Soling, Acta Chem. Scand. (A), 1976, 30, 163. 322 325 104 Inorganic Chemistry of the Main -Group Elements produced, with the probable structure (72). In DMSO as solvent, this dimer is cleaved, to give a solvated monomer (Htdt)In(OAc) (DMSO)Me.,,’ (72) The potassium bis(se1enato)indate KIn(Se0,),,4H20 can be isolated from the K2Se0,-In,(SeO,),-H,O Phase relationships have been elucidated in the system InC1,-Cs,P,O,,-H,O at 0 “C. The species Cs,InP,O,,,xH,O was isolated.’3o The crystal structures of LnInO,, where Ln=Eu-Ho, or Y, have been determined. They show that the In3+cations are situated at five-co-ordinate trigonal-bipyramidal sites -331 y-In& can only be quenched to room temperature in the presence of 5 atom O h of As or Sb. The S atoms in such a system are cubic close-packed, with all of the In atoms in octahedral holes.,,, The phase diagrams of the systems GeSe,-In,Se, and Ge-In,Se, have been cons tru~ted.,~, lnTe is tetragonal, of space group I4/mcm. There are two types of In atom site; one is approximately tetrahedrally co-ordinated, while the second is surrounded by a cage of eight Te atoms, with two further Te atoms along the c-axis. The latter In can be described as an isolated In+.?,, In,Te, is monoclinic, belonging to space group Cc. The structure is built up from four-membered In-Te rings, linked by Te, units. Each In atom is tetrahed- rally co-ordinated, and the average In-Te bond length is 2.832(6) A.335 The systems InAs-MIn2Te,, where M = Zn or Cd, form homogeneous solid solutions throughout the composition ranges.336 The phase diagram of the TlInTe,-InGaTe, system has been determined.337 Indium Halides.-Heating appropriate mixtures of the binary compounds in a closed system produces the new compounds M,M’InF6, where M2 = Rb,, M’ = Ag or Cs; M2 = RbT1, M’ = Na, Ag, or K; M2 = Tlz, M’ = Ag; M2 = Cs,, M’ = Ag.,,’ 328 J . J . Habeeb and D. G. Tuck, J. OrgunometuUic Chem., 1975, 101, 1. N. V. Kadoshnikova, E. N. Deichman, I. V. Tananaev, and Yu. Ya. Kharitonov, Russ. J. Inorg. Chem., 1975,20, 1150. G. V. Rodicheva, E. N. Deichman, I. V. Tananaev, and Zh. K. Shaidarbekova, Russ. J. Inorg. Chem., 1975, 20, 1316. 329 330 331 C. W. F. T. Pistonus and G. J . Kruger, J. Inorg. Nuclear Chem., 1976, 38, 1471. 332 R. Diehl, C. D. Charpentier, and R. Nitsche, Actu Cryst., 1976, B32, 1257. 333 P. G. Rustamov and B. K. Babaeva, Russ. J. Inorg. Chern., 1975, 20, 1360. 334 J. H. C. Hogg and H. H. Sutherland, Actu Cryst., 1976, B32, 2659. 33s H. H. Sutherland, J. H. C. Hogg, and P. D. Walton, Actu Cryst., 1976, B32, 2539. V. P. Drobyazko and S. T. Kuznetsova, Russ. J. Inorg. Chem., 1975, 20, 1693. E. M. Godzhaev, Sh. M. Guscinova, F. M. Novruzova, M. M. Dadashev, and B. B. Guseinova, Russ. J. Inorg. Chem., 1975, 20, 1704. J . Setter and R. Hoppe, 2. anorg. Chem., 1976, 423, 125. 336 337 338 Elements of Group III 105 The mass spectra of the vapours above the mixtures InCl-InCl, and GaCl- GaCl, reveal the existence of In,Cb, In,Cl,, In,C12, InCl,, and InCl and of Ga&, Ga2C14, GaCl,, and GaCL3,' Convenient routes to the lower halides of In have been summarized. Thus InX, in xylene as a solvent reacts readily with In metal to give pure, crystalline InX,, where X = I, Br, or C1. Treatment of these dihalides with Et20 or other Lewis bases leads to precipitation of the insoluble I S , as a very finely divided, reactive form, together with the InX,base addu~t.~~' CpIn reacts with equimalar quantities of HX and Et4NX in organic solvents to form crystalline Et,NInX, (X = C1, Br, or I). Vibrational spectra show that the InX; ions are bent monomers, as for SnX,. Thus, InC1, gives vl at 328 (R), 330 (ix.); v, 117 (R); v3 291 (R), 291 (i.r.)crr-'. [In(NCO),]-, [In(NCS),]-, and [In(NCS)]$- are prepared by metathetical reactions with InIi- or InI$-. These salts contain bridging ligands; thus [In(NCO),]- gives v(CN) at 2175 and 2195 crn-l.,,l A general method for the direct synthesis of indium compounds (cationic, anionic, or neutral) has been proposed, using an electrochemical technique. Indium acts as an anode, with Pt as cathode, and the solution phase is benzene (or other aromatic compound) containing 10-20% alcohol. Crystalline halides InX,, In(acac),, [In(DMSO),] (C104)3, InClz-, etc. can all be prepared in this way.342 The crystal structure of indium trichloride trihydrate trisdioxan, InC1,,3H,0,3C4H,02, has been determined. An indium atom is at the centre of a distorted octahedron (3 C1 and 3OH,), and the layers are held together by H-bonding to dioxan The equilibrium diagram of the InC1,-py-H,O system at 25°C reveals the existence of two compounds, i.e. InC13,py,2H,0 and I nC1,,3~y.~,~ Me4M' MeInC1, (M = As or Sb) both crystallize in the monoclinic space group Pc. Isolated tetrahedral ions are found in both, the ions of course being very distorted. r(1n-C1) is 2.388 A and r(1n-C) 2.183 A.345 The crystal structure of K21nC15,Hz0 reveals that the In is co-ordinated by five C1and one OH2, to give a distorted InX, and Bu,NX react in xylene to form (Bu,N),(In,&), where X = C1, Br, or I. The vibrational spectra of all of these were analysed, and were consistent with the formulation (X,In-1nX,)2-, i.e. they are unambiguously In" species. For In2Cg-, the symmetric In-C1 and In-In stretches are at 289 and 174 crr-l, respectively. The position of v(1n-In) is markedly dependent on X (174, 139, and 108 cm-' for X = C1, Br, and I, respectively); therefore it is strongly coupled with ~( I nx) . , ~~ Electromigration experiments on solutions of indium tribromide in ester media point to the formation of ions by a halogenotropic mechanism. Species such as (InBr,,2E)', (InBr4)-, (In,Br5,2E)', and (InzBr7)- were thought to be involved, 339 H. Schafer and M. BiMewies, Rev. Chim. minerale, 1976, 13, 24. 340 B. H. Freeland and D. G. Tuck, Inorg. Chem., 1976, 15, 475. 341 J. J. Habeeb and D. G. Tuck, J.C.S. Dalton, 1976, 866. 342 J. J. Habeeb and D. G. Tuck, J.C.S. Chem. Comm., 1975, 808. 343 S. H. Whitlow and E. J. Gabe, Acta Cryst., 1975, B31, 2534. 344 E. M. Kartzmark, Canad. J. Chem., 1975, 53, 2995. 34s H. J. Guder, W. Schwarz, J. Weidlein, H. J. Wider, and H. D. Hausen, 2. Naturforsch., 1976, 31b, 1185. J. P. Wignacourt, G. Mairesse, and P. Barbier, Cryst. Struct. Comm., 1976, 5, 293. 346 347 B. H. Freeland, J. L. Hencher, D. G. Tuck, and J. G. Contreras, Inorg. Chem., 1976, 15,2144. 106 Inorganic Chemistry of the Main - Group Elements where E = propyl acetate, butyl formate, ethyl propionate, or ethyl butyrate. Spectroscopic investigations (i.r. and 'H n.m.r.) showed that no appreciable amounts of R', RCO', or RC(0H)OR" were formed.348 Studies of the InBr3-NaBr-H,O system at 25 "C reveal that no hydrated forms of InBr, exist at that temperat~re.~~' Phase diagrams have been constructed for the following systems: MBr,-InBr, (M = Ca, Sr, or Ba)350 or (M = Mn, Co, or Ni),351 InBr,-AlBr,, InBr,-SnBr,, and InBr,-TeBr4.352 InBr,-TlBr and In13-TlI systems have also been investigated, The former contains the compounds T131nBr, and TlInBr,, decomposing at 340 "C and 210"C, respectively. The latter system gives evidence for TlInI, and 9Tl1,l 11nI,.353 The interplanar spacings of red InI, have been deduced from the X-ray powder diffraction data.354 Electrical canductivities of molten InI-ZnI, and InI-PbI, mixtures have been used to determine the electrical properties of InPbI, and A number of salts R(InI,), where R = various tetra-alkylammonium cations, have been isolated for the fist the. Their i.r. spectra showed all the features to be expected for the anion and the * 5 Thallium Thallium(m) Compounds.-Potentiometric methods have been used to investi- gate the hydrolysis of Tl"' ions in H,O-DMSO and H,O-acetone The 205"1 n.m.r. frequency in (substituted aryl)thallium(m) bis(trifluor0acetate) compounds is very sensitive to the nature of the aryl substituent. A correlation exists between the frequency and the Hammett 0-parameter for the substituent, and also the 205Tl-'H coupling constants.358 The dimethylthallium(rI1) compounds Me,TlX, where X = OCOMe-, and (Me,Tl),X', where X' = malonate, succinate, maleate, fumarate, CO:-, or S&, may be prepared in high yields (greater than 80%) and in one step by anion exchange between Me,TlBr and the appropriate T1' compound.359 Me2T1NMe2 and Me,TlOEt undergo insertion reactions into the T1-N or T1-0 bond on reaction with RNCS, PhNCO, CS2, COS, CO,, SO2, or SO3. The Yu. A. Lysenko, V. V. Pinchuk, and A. A. Kuropatova, J. Gen. Chem. (U.S.S.R.), 1975, 45, 894. 349 E. M. Kartzmark, Canad. J. Chem., 1976, S4, 1884. A. G. Dudareva, Yu. E. Bogatov, V. Ya. Lityagov, A. K. Molodkin, and A. I. Ezhov, Russ. J. Inorg. 3.50 Chem., 1975, 20, 1368. 351 A. G. Dudareva, Yu. E. Bogatov, V. Ya. Lityagov, and A. K.*Molodkin, Russ. J. Inorg. Chem., 1975, 20, 1422. 3s2 A. G. Dudareva, Yu. E. Bogatov, E. V. Galenko, A. K. Molodkin, and V. Ya. Lityagov, Russ. J. Inorg. Chem., 1975, 20, 1586. 3s3 A. G. Dudareva, N. N. Mel'nikov, K. A. Aleksakhan, Yu. E. Bogatov, and P. I. Fedorov, Russ. J. Inorg. Chem., 1975, 20, 1365. 354 P. I. Fedorov and N. S. Malova, Russ. J. Inorg. Chem., 1975, 20, 1265. 3ss Yu. N. Denisov, N. S. Malova, and P. I. Fedorov, Russ. J. Inorg. Chem., 1975, 20, 1741. 35h V. S. Mal'tseva and Yu. G. Eremin, Russ. J. Inorg. Chem., 1975, 20, 670. 357 F. Ya. Kul'ba, D. A. Zenchenko, and Yu. B. Yakovlev, Russ. J. Inorg. Chem., 1975, 20, 1464. 3s8 J. F. Hinton and R. W. Briggs, J. Magn. Resonance, 1976, 22, 447. 3s9 V. Knips and F. Huber, J. Organometallic Chem., 1976, 107, 9. 348 Elements of Group III 107 (73) products are (73), where E=NMe,, Y=S, X=NPh, NMe, S, or 0; E=NMe,, Y = 0, X = NPh or 0; E = OEt, X = NPh, Y = S or 0.360 Thallium(I) Compounds.-The 205Tl n.m.r. chemical shift of T1' in donating solvents correlates linearly with the donor power of the solvent towards TI'. This can be rationalized simply in terms of symmetry considerations of M.O. Calculated and thermodynamic values of the cohesive energies of a- and P-TIF are in good agreement, and consistent with their having ionic 1.r. and Raman spectra have been obtained for monomeric and dimeric TI' halides in Ar matrices: TlF, T12Fz, TlCl, and Tl2Cl2. Dimers have planar rhombic structures, not the linear configurations previously assigned. The present results agree with an electron-diffraction study on T12F2, Thermal analysis and solubility studies reveal that the following species are formed in the HF-TIF system: TlF,7HF, 2T1F, 13HF, TIF,SHF, TlF,3HF, TIF,2HF, 2TlF,3HF, and T1F,HF.364 A study of the reaction of gaseous 0, with pure TI,S showed that the T1is oxidized in preference to the S, giving compounds formulated as T1,SO and T ~~so, . ~~~ Thallium reacts with absolute EtOH in the presence of 0, to form Tl(OEt), which separates as a second phase. Some i.r. assignments have been Mixed complexes 'Il(S,O,)NO~- and Tl(S,O,);- are formed in the NaN03- Na2S,O3-T1IO3-Hz0 system. Their stability constants are 0.83 f 0.05 and 0.43 * 0.04, re~pectively.~~' There are two distinct types of TI atom in T12S,03. The Tl(1) atom is co-ordinated to two 0 atoms at 3.15A, five 0 or S atoms at between 3.07 and 3.2& and three 0 or S atoms at about 3.46A. Tl(2) is co-ordinated to two 0 atoms at 2.91, 3.06& and seven S or 0 atoms at between 3.11 and 3.29A. Comparison with the isostructural Rb,S04 suggests that the T1 ions are not stereochemically active in this The crystal structure of thallium(1) dibutyldithiocarbamate, TlS2CNBu,, is built up from centrosymmetric dimers linked by TI-S co-ordination to give layers parallel to the bc plane. The T1is co-ordinated to four S atoms (2.97-3.16A) within the dimer, and two more distant S atoms, at 3.98 and 4.19 A. The structure is very like that of the Cs' analogue.369 360 B. Walther, R. Mahrwald, C. Jahn, and W. Mar, 2. anorg. Chem., 1976, 423, 144. 361 J. J . Dechter and J. I. Zink, Inorg. Chem., 1976, 15, 1690. 362 M. F. C. Ladd, J.C.S. Dalton, 1976, 1248. 363 M. L. Lesiecki and J. W. Nibler, J. Chem. Phys., 1976, 63, 3452. 364 M.-J. Boinon, G. Coffy, and A. Tranquard, Bull. SOC. chim. France, 1975, 2380. 365 V. I. Rigin and S. S. Batsanov, Russ. J. Inorg. Chem., 1975, 20, 1283. 366 E. P. Turevskaya, N. Ya. Turova, and A. V. Novoselova, Rwss. J. Inorg. Chem., 1975, 20, 838. 367 E. A. Gyunner and A. M. Fedorenko, Rwss. J. Inorg. Chem., 1975, 20, 841. 368 J.-E. Anderson and B. Bosson, Acra Cryst., 1976, B32, 2225. 369 E. Elfwing, H. hacker-Eickhoff, P. Jennische, and R. Hesse, Actu Chem. Scund. (A), 1976, 30, 335. 108 Inorganic Chemistry of the Main-Group Elements The crystal structures of TlD,PO, and Tl,DPO, show that both are orthorhom- bic, of space groups &am or Pna21.370 The stability of T1' derivatives TlK, where R is a substituted metal carbonyl anion, depends upon the size of R and the percentage covalent character of the TI-M bond. For small R, only those compounds with weak covalency in the TI-M bond are isolable. In general, the lower the basicity of R, the greater the stability of TlR. Larger R groups give more stable T1' species than do small ones.371 TlCo(CO), forms Tl' compounds TICO(CO)~L, which are isolable in solution, with those bases L which form cobalt carbonyl anions of low basicity (pKa<5), e.g. L = P(OPh),, P(OC6H4-C1-p),. When L gives an anion of higber basicity, Tl"' derivatives are produced, e.g. L = PPh,, AsPh,, or SbPh3.372 PPh3Me[Tl(q4-B10H12)Me2] forms orthorhombic crystals, belonging to the space group Pbca. In the anion the TI atom is bonded to two Me groups [2.23(3) A] and four B atoms (see Figure 15). There is no indication that there is c m R Figure 15 Structure and numbering scheme of the anion [Tl(q4-B10H12)Me,]-; hydrogen atoms are omitted for clarity (Reproduced from J.C.S. Dulton, 1976, 177) preferential q2-bonding to B(5)-B(6), which had been suggested after a study of Other Thallium Compounds.-The phase diagrams of the systems As,Te,-TlTe and As,Te,-Tl,Te have been de te~rnined.,~, Several new phases have been identified and characterized in the systems T1- Cr-X ( X=S or Se); these are TlCrS,, TlCr3S5, TlCr,S,, TlCrSe,, T1Cr,Se5, and T~,CTS~,.~~' B n.m.r. spectra in donor 11 370 Y. Oddon, J. R. Vignalou, G. Co@, and A. Tranquard, Bull. SOC. chirn. France, 1976, 334. 371 S. E. Pedersen and W. R. Robinson, Inorg. Chern., 1975,14,2365. S. E. Pedersen and W. R. Robinson, Inorg. Chern., 1975, 14, 2360. N. N. Greenwood and J. A. Howard, J. C. S. Dalton, 1976, 177. 1687. 372 373 374 G. M. Orlova, V. R. Panus, I. I. Kozhina, and I. A. Yancheskaya, Russ. J. Inorg. Chern., 1975, 20, 375 C. Platte and H. Sabrowsky, Natunviss., 1975, 62, 528. 4 El ements of Group IV BY P. G. HARRISON 1 Carbon Carbon Allotropes.-The kinetics of growth of diamond from ethyne and ethene have been investigated, and there has been a study of the influence of hydrogen on the rate of growth.' A multitude of papers report the preparation of graphites from organic precursors, usually employing a metal as catalyst. Aluminium powder catalyses the graphitization of a phenolic resin at temperatures of up to 2000°C under a nitrogen atmosphere. AlN is thought to be formed first, which then reacts with the carbon matrix to form the intermediate A14C3. This com- pound is then considered to penetrate into the surrounding carbon matrix through a sequence of formation and decay of A14C3, leaving crystalline graphite The role of titanium and zirconium as catalysts for the graphitization of Gilsonite pitch and acenaphthylene, as well as a phenol-hexamine resin, has been st~di ed.~ Again, diffusion of the metal into the carbon matrix is significant, but there is no evidence of carbide formation. The extent of graphitization increases with metal content up to ca. 10% of metal. The carbonization of aromatic hydrocarbons is catalysed by alkali metals.4y5 The hydrocarbons studied were, in every case, carbonized into isotropic carbons, in contrast to the same reactions catalysed by aluminium trichloride, which produced anisotropic, needle-like coke. Carbon layers have been deposited on iron and its alloys with nickel and copper by the catalytic decomposition of acetone in carbon dioxide at 700°C. Nickel was identified as the major promoter of deposition of carbon under these conditions, although iron is also active.6 Carbons have been prepared from pure and doped furfuryl alcohol, doping being accomplished by the addition of a known amount of a metal nitrate solution. The metal (Ni, Co, Fe, Ag, Cu, or Ca) within the carbon is considered to be dispersed as atoms or as small aggregates. Such dispersions are catalytically active in the gasification of carbons by carbon dioxide, nitrous oxide, and oxygen. The relative catalytic activities of the metals decrease in the order Ni > Co > Cu > Ag > Fe > Ca.7 The formation of carbon on nickel sheet from ' D. V. Fedoseev, K. S. Uspenskaya, and B. V. Deryagin, Russ. J. Phys. Chem., 1976, 49, 1580. * A. Oya and S. Otani, Carbon, 1976, 14, 191. H. Marsh and A. P. Warburton, Carbon, 1976, 14, 47. I. Mochida, E. I. Nakamura, K. Maeda, and K. Takeshita, Carbon, 1975, 13,489. I. Mochida, E. I. Nakamura, K. Maeda, and K. Takeshita, Carbon, 1976, 14, 123. M. J. Durham and J. E. Castle, Carbon, 1976, 14, 27. ' H. Marsh and R. R. Adair, Carbon, 1975, 13, 327. 109 110 Inorganic Chemistry of the Main-Group Elements benzene vapour carried by hydrogen has been studied in the temperature range 520-730 "C.' The maximum rate is observed at -630 "C, above which the rate of deposition decreased rapidly. The carbon was hydrogenated in situ, giving methane as the major gaseous product. The very high reactivity of the deposited carbon towards hydrogenation was ascribed to the catalytic action of nickel particles dispersed in the carbon. A series of microporous carbons prepared from cellulose triacetate by heat treatment in the temperature range 1230-2275 K have been converted into a second series by activation to 30% burn-off by reaction with carbon dioxide. The changes in porosity with the temperature of the heat treatment were investigated by measurement of adsorption of carbon dioxide in the temperature range 195-248 K and by measurement of Hg densities. The predominant effect of heat treatment was found to be the conversion of open micropores into closed micropores with little change in the total pore volume. Activation of carbons made at 1230 and 1475 K is confined almost entirely to the development of micro pore^.^A mixture of carbon and lithium fluoride, dispersed on a molecular scale, has been prepared at 100 "C by corrosion of polytetrafluoro- ethylene, using lithium amalgam. The corrosion mechanism was found to be electrochemical. Very highly dispersed amorphous carbon having a specific sur- face area of 3.5-4.0~ lo3 m2 8-l could be isolated from the mixture by melting or dissolving the lithium fluoride partic1es.l' A continuous fibre of silicon carbide, of very high tensile strength, has been prepared from a polycarbosilane. It begins to decompose from 300"C, and is gradually converted into a @-silicon carbide fibre by heat-treatment at temperatures above 800 "C.li The structure and dynamics of 'graphon', a carbon black, have been charac- terized by a combination of neutron-diffraction and inelastic scattering experi- ments.I2 Unit-cell dimensions have been measured, and the average dimensions of the layer lattice estimated, from high-angle diffraction, to be La = 30 8, and L, = 85 A. The transient presence of interstitial carbons in the process of transfor- mation of a coke into graphite has been deduced from a study of the radial distribution function. A peak corresponding to an abnormal C-C interatomic distance of 1.90 A observed for samples heat-treated to 2050 and to 2100 "C has been assigned to interstitial carbon atoms located 1.2 8, above or below the hexagonal carbon layers, at the centre of the hexagonal rings.I3 The structure of a phenol-formaldehyde resin char and its changes with heat-treatment to tempera- tures from 1600 to 2700 "C have been studied by polarized light microscopy and X-ray diffraction. Concentric carbon layers are observed to be aligned along the periphery of pores that have diameters of the order of 100 pm. The results imply that graphitization takes place in pockets of carbon layers around pores that were formed in the processes of hardening and carbonization of the resin, while the isotropic carbon matrix is left ~ngraphitized.'~ Petroleum and pitch cokes with 0.4-1.7 wt.% of sulphur show an increased tendency towards graphitization of the Y. Nishiyama and Y. Tamai, Carbon, 1976, 14, 13. B. McEnaney and N. Dovaston, Carbon, 1975, 13, 515. lo J. Jansta, F. P. Dousek, and V. Patzdova, Carbon, 1975, 13, 377. l1 S. Yajima, K. Okamura, and J. Hayashi, Chem. Letters, 1975, 1209. l2 P. H. Gamlen and J. W. White, J.C.S. Faraday 11, 1976, 72, 446. l 3 J. P. Rouchy and L. Gatineau, Carbon, 1975, 13, 267. l4 K. Kamiya and K. Suzuki, Carbon, 1975,13, 317. Elements of Group IV 111 main part of the sample with increasing sulphur content. X-Ray diffraction measurements show that the irreversible contraction of the inter-layer distance starts during heating below 1500 "C, and the activation energy of graphitization falls from 7-10 eV to ca. 3-4 eV between 1400 and 2000 "C; this is caused by the catalytic effect of the s~l phur.~' The effect of surface irregularities, grain boundaries, and crystal orientation on the formation of carbon on nickel from ethyne at low pressures and at temperatures between 450 and 600°C has been investigated.16 Formation of carbon is enhanced if the surface is rough and if grain boundaries are present. This has been rationalized by a mechanism which involves nickel particles. Thirteen anthracites of various origin have been studied by electron microscopy, microdifiaction, and bright-field, dark-field, and Iattice imaging in the raw and progressively heat-treated states. The anthracites behave like hard carbons below a heat-treatment temperature of 2000°C and like soft carbons above 2500 "C.I7 Chemical Reactions.-Carbon vapour produced by laser irradiation has been found to react with water vapour, producing CO, H,, and C,H, as the major products.'* Corrosion reactions of various nuclear graphites with hydrogen have been studied in the temperature range 970-1090 "C in a helium stream. Methane is the only gaseous product observed. Rates of reaction and the influence of the partial pressure of hydrogen were also examined.lg The hydrogasification activity of Ni-impregnated active carbon is severely reduced by alloying Ni with a relatively inert metal such as copper.2o Hydrogenation of carbon to methane in reduced sponge Fe, Cr, and ferrochromium, under isothermal and temperature- programmed conditions, indicates that it is possible to control the residual carbon content of the metallized products.2' Results of several kinetic studies have been plblished: the kinetics of oxidation of spectroscopic grade polycrystalline graphite, studied by a flow method at ca. 1000K;22 the kinetics of the graphon- CO, reaction under conditions of continuous linear temperature and the kinetics of the reaction of SO, with carbon, with and without added catalyst^.,^A retardation of the gasification reaction of carbon with 0, by SO, has been observed. Infrared internal reflectance spectroscopy was used to investigate the nature of the surface species formed on the reacted charcoal samples, and bands were assigned to surface carbonyls, lactones, and a chemisorbed SO, in the form of a sulphate. This latter species was thought to be responsible for the retardation.,' Measurements of the retention of ethylene glycol and X-ray-induced photoelectron spectroscopy have been used to follow the oxidation processes in both a natural and an artificial graphite. Both indicate that the oxidation process l5 E. Fitzer and S. Weisenburger, Carbon, 1976, 14, 195. l6 C. Bernado and D. L. Trimm, Carbon, 1976, 14, 225. l7 A. Oberlin and G. Terriere, Carbon, 1975, 13, 367. l8 P. H. Kim, K. Taki, and S. Namba, Bull. Chem. SOC. Japan, 1975, 2953. l9 H. Imai, S. Namura, and Y. Sasaki, Carbon, 1975,13, 333. 2o S. D. Robertson, N. Mulder, and R. Prim, Carbon, 1975, 13, 348. *' M. A. Qayyon and D. A. Reeve, Carbon, 1976, 14, 199. 22 R. J. Tyler, H. J. Waterlood, and M. F. R. Mulcahy, Carbon, 1976, 14, 271. 23 R. Phillips, F. J. Vastola, and P. L. Walker, Carbon, 1976, 14, 83. 24 H. Abramowitz, R. Insinga, and Y. K. Rao, Carbon, 1976, 14, 84. '' R. T. Yano and M. Steinberg, Carbon, 1975, 13, 411. 112 Inorganic Chemistry of the Main -Group Elements is complete after ca. 24-32 h.,, The reactions which occur in different gaseous environments between graphite and alkali-metal carbonates and oxides have been studied by simultaneous t.g.a.4.t.a. and hot-stage microscopy. The catalytic effects of these salts during gasification of graphite in 0, and CO, were inter- preted on the basis of distinct oxidation-reduction cycles involving the inter- mediate formation of peroxide in the former case and alkali metal in the latter.27 Samples of carbon (Spheron 6) and graphite have been degassed at temperatures up to 800°C, and the decomposition of surface oxides to CO and CO, has been followed with a mass spectrometer. Changes in the concentration of surface groups on the degassed samples were also followed by their reaction with MeMgI, and it was concluded that cyclic esters are primarily responsible for surface acidity.28 The alkaline hydrolysis of alkylated acidic groups on carbon black (formed by the treatment of carbon black with C,-Cs n-alcohols in the vapour or liquid phase) has been studied potentiometrically. The hydrolysis proceeds more rapidly for the carbon blacks which have been treated with the lower alcohols. Hydrolysis rates also decreased with time, and after the hydrolysis rate had diminished, a hydrolysis-resistant fraction of alkylated groups remained.29 Polymerization of vinyl monomers has been carried out in the presence of furnace carbon blacks, using initiators such as AIBN or dibenzoyl peroxide in a nitrogen or oxygen atmosphere. The results indicate that free radicals formed by the decomposition of the initiators react with the carbon blacks to give active sites on their surface, which then capture either the free radicals or the growing polymer radicals .30 The adsorption of neon on graphitized carbon in submonolayer and multi-layer regions has been investigated between 1.5 and 30 K. Heat capacities and heats of adsorption, together with equilibrium pressures, were reported for coverages up to three mon01ayers.~’ Adsorption isotherms for EtOH-cyclohexane, EtOH- C6H6, and C,H,-cyclohexane vapour mixtures and the pure vapours on Graphon at 20, 30, and 40°C have been measured at constant total pressure. Very little selective adsorption occurred with the C,H,-cyclohexane mixture, but C6H6 and cyclohexane were selectively adsorbed from their mixtures with EtOH.32 Adsorp- tion of iodine onto activated carbons from the vapour as well as from aqueous solution has been examined. From solution, a unimolecular layer is formed on the carbon surface, whilst pore-filling of the micropores and surface coverage of the macropores occurs from the vapour phase.33 The adsorption of iodine by coal and lignite has also been The adsorption of CNCl on impregnated carbons containing Cu and Cr compounds and other additives is accompanied by the formation of CO,. Presorbed water enhances the formation of CO, and 26 E. L. Evans, J . de D. Lopez-Gonzalez, A. Martin-Rodriguez, and F. Rodriguez-Reinoso, Carbon, ” D. W. McKee and D. Chatterji, Carbon, 1975, 13, 381. 29 Y. Matsumura, S. Hagiwara, and H. Takahashi, Carbon, 1976, 14, 247. 30 K. Ohkita, N. Tsubokawa, E. Saitoh, M. Noda, and N. Takeshita, Carbon, 1975, 13, 443. 31 A. A. Antoniou, J. Chem. Phys., 1976, 64, 4901. ’* G. A. Perfetti and J . P. Wightman, Carbon, 1975, 13, 473. 33 A. J. Juhola, Carbon, 1975, 13, 437. 34 S. Aronson, A. Schwebel, and G. Sinensky, Carbon, 1976, 14, 93. 1975, 13, 461. S. S. Barton and B. H. Harrison, Carbon, 1975, 13, 283. Elements of Group IV 113 decreases the desorption of ONCl.35 The effect of pretreatment with amine on the adsorption of CNCl by Cu-, Ag-, and Cr-impregnated charcoals has been studied.36 Intercala~on Compounds.--l'he action of solutions of conjugated aromatic hydro- carbons in THF on binary graphite-alkali-metal compounds such as KC,, KC,,, KCS6, or KC,, yields well-defined dark ternary compounds of the type KC,(THF) ( n = 24, 36, 48, or 72).37 The lamellar compound KC, also forms a well-defined lamellar complex with benzene and THF, and because of its high affinity for hydrogen it causes conversion of benzene into biphenyl.,' The K-graphite inter- calate KC,, can act as a catalyst for the reduction of alkenes and alkynes, is a very efficient catalyst for the isomerization of cis- to trans-stilbene, and can promote deuterium exchange with hydrogens carried by hydrocarbons having an acidity higher than or equal to that of benzene.39 Lamellar graphite-lithium compounds of the first (brass-yellow), second (steel blue), third (dark blue), and fourth (black) stages have been prepared either by heating graphite and lithium at 400°C in a copper or stainless-steel tube, or by compressing lithium powder with crushed natural graphite under an argon atmosphere in a glove box at room temperature. The compound of the first stage has the formula LiC, and that of the second stage LiC,,; both are hexagonal?' Various metal halides have been intercalated into graphite lattices, including UF,;' XeF6;* MgCl2? TiX, (X = C1or F): SbCl5?' and the chlorides of Al, Fe'", Ni", Ptw, Pd", Cu", Rh"', Uw, MoV, and Wv'?6 A technique has been described which distinguishes between the amount of AlCl, that is intercalated by a carbon and the amount that adds in other ways.47 Molten CrO, will intercalate very thin flakes of graphite to give C,,CrO,. With thicker flakes the amount is less, and C150Cr03 is Experimental isotherms indicate that thiocyanate and tetracyanonickelate(I1) are adsorbed to an equal extent from waste solu- t i on~. ~~ The preparation of graphite-alkali metal-solvent and of graphite-N&- solvent ternary intercalation compounds by electroreduction of graphite has been described. Reduction occurs stepwise, and the complete formation of a defined stage can be recognized by a striking change in the potential of the graphite el ectr~de.~~ 35 Z. Barnir and C. Aharoni, Carbon, 1975, 13, 363. 36 J. A. Baker and E. J. Poziome, Carbon, 1975, 13, 347. 37 F. Beguin and R. Setton, Carbon, 1975, 13, 293. 38 F. Beguin and R. Setton, J.C.S. Chem. Comm., 1976, 611. 39 J . M. Lalancette and R. Roussel, Canad. J. Chern., 1976, 54, 2110. 40 D. Guerard and A. Herold, Carbon, 1975, 13, 337. 41 Y. Binenbeyon, H. Selig, and S. Sarig, J. Inorg. Nuclear a m . , 1976, 38, 2313. 42 H. Selig, M. Rabinowitz, I. Agranat, C. H. Lin, and L. Ebert, J. Amer. Chem. Soc., 1976,98, 1601. 43 E. Stumpp and A. Terlan, Carbon, 1976, 14, 89. 44 E. Buscarlet, Ph. Touzain, and L. Bonnetain, Carbon, 1976, 14, 75. " J. Mein and A. Herold, Carbon, 1975, 13, 357. 47 J. G. Hooley, Carbon, 1975, 13, 469. 48 J. G. Hooley and M. Reiner, Carbon, 1975, 13, 401. 49 R. G. Kunz and J. F. Gianelli, Carbon, 1975, 14, 157. J. M. Lalancette, L. Roy, and J. Lafontaine, Canad. J. Chem., 1976, 54, 2505. 46 J. 0. Besenhard, Carbon, 1976, 14, 111. 114 Inorganic Chemistry of the Main- Group Elements Carbon Compounds.-Hydrocarbons. Chemical accelerator studies on isotopic variants of the reaction NZ + CH4 + N2H++ CH, have been reported. The excita- tion function is at a maximum at ca. 5 eV and decreases at lower collision energies, appearing to possess a threshold at 0.1 eV. At higher energies there is a large isotope effect, favouring abstraction of H over D.5' The reaction of OH radicals (formed either by photolysis of H,02 in the presence of O2 or by the photolysis of N,O in excess H,) with C2H4 has been studied. The HO radicals attack C2H4 by two routes: (i) H-abstraction to give H,O and C,H, radicals, which are oxidized to give CH,O and HC02H, or (ii) association to give HOC2@ energized radical adducts, which give products of high molecular weight and CO, in the presence of H,O, and added oxygen. Without added oxygen, other products (e.g. EtOH) are formed.52 The gas-phase reactions of ground-state (triplet) 0 atoms (generated by Hg-photosensitized decomposition of N20) with 2-methyl-[2H,lpropene, -[l-2HJ propene, and -[ 1, l-2H21propene, and of ozone with C2H4, MeCH=CH,, and trans -but-2-ene have been i n~esti gated,~~"~ as well as the reaction of 0 atoms [produced by a microwave discharge through a helium (90% )-oxygen( 1O0/o) mixture] with dicyanoacetylene .55 Halogen Derivatives. Structural studies of CC12=CF2,56 (CF3)3CC157 (both by electron diffraction), and CH,DF58 (by microwave) have been reported. A de- tailed vibrational study of four isotopic species of BrClFCH has been presented, and used to calculate a generalized valence force field, employing structural parameters from the electron-diffraction A large number of detailed studies of the reactions of halogenocarbons with various species have been reported. Rate-constant data for the reactions of OH radicals with a wide range of halogenocarbons, including CH3C1, CH2C12, CHC13, and CH,Br,"' CH, and fifteen F-, Cl-, and Br-substituted methane derivatives:' CHFCl,, CH,C1, and CH2Cl2:' CHF,Cl, CF2C12, and CFC13:3 and C,H, and twelve F-, C1-, and Br-substituted ethane compounds have been published.64 The data indicate a mechanism that involves the abstraction of an H atom and the formation of H,O and an alkyl radical. Thus the completely halogenated deriva- tives were found to be relatively inert. The CO*' ion reacts with CF4 at nearly the collision limit, while the almost isoenergetic ions CO,.' and Kr-' do not exhibit measurable rate constants. It was proposed that the COO' ion reacts to form a stable COF- product via an abstraction process. All three ions react with C2F6 " J. R. Wyatt, L. W. Stratten, S. C. Snyder, and P. M. Hierl, J. Chem. Phys., 1976, 64, 3757. 52 J. F. Meagher and J. Heicklen, J. Phys. Chem., 1976, SO, 1645. 53 J. J. Have1 and C. J. Hunt, J. Phys. Chem., 1976, 80, 779. 54 S. M. Japar, C. H. Wu, and H. Niki, J. Phys. Chem., 1976, 80, 2057. 55 C. W. Hand and R. M. Myers, J. Phys. Chem., 1976, 80, 557. 56 A. H. Lavrey, P. D'Antonio, and C. George, J. Chem. Phys., 1976, 64, 2884. 57 A. Yokozeki and S. H. Bauer,-J. Phys. Chem., 1976, 80, 73. '* W. W. Clark and F. C. De Lucia, J. Mol. Structure, 1976, 32, 29. 59 M. Diem and D. F. Barrow, J. Chem. Phys., 1976, 64,5179. 6o D. D. Davis, G. Machado, B. Conaway, Y. Oh, and R. Watson, J. Chem. Phys., 1976, 65, 1268. 62 R. A. Perry, R. Atkinson, and J. N. Pitts, J. Chem. Phys., 1976, 64, 1618. 63 R. Atkinson, D. A. Hansen, and J. N. Pitts, J. Chem. Phys., 1975, 63, 1703. h4 C. J. Howard and K. M. Evenson, J. Chem. Phys., 1976, 64, 4303. C. J. Howard and K. M. Evenson, J. Chem. Phys., 1976, 64, 197. Elements of Group IV 115 and C,F8.65 The reaction between F atoms and CF,H to give HF and CF3* radicals has been studied, using a fast flow reactor, with e.s.r. detection.66 New procedures have been reported for the specification of caging yields in nuclear recoil experiments. All five hot "F substitution channels in CH,CF, and CH,CHF, exhibit caging at high density. The simplest plausible caging mechanism involves primary Franck-Rabinowitsch radical recombination of 18F atoms with aliphatic radical^.^^A kinetic study of the gas-phase reaction between C,F,I and HI has shown that the rate-determining step is the abstraction, by an iodine atom, of iodine from C2F51 to give a C,F5* radical and The reaction of ozonized oxygen with 1,l-difluoroethane and l,l,l-trifluoroethane has been studied by i.r. spectroscopy. The observed products in the latter case were CO,, COF,, HC02H, and H20, whilst ozonization of the former yields additionally CO, CH,COF, and CH,C0,H.69 Ozonization of C2F4 in the gaseous phase yields several products, the nature of which depend on the conditions and the ratio of reactants. When a 1 : 1 ratio of reactants is used, the ozonide C2F403 is obtained, but when C2F4 is in excess, other products (including COF,, the epoxide C,F,O, and small amounts of CyClO-c,F6) are formed.70 The kinetics of the reaction of CF,=CH, with bromine have been investigated, from which a mechanism that involves initial homolytic dissociation of Br,, attack of a bromine atom at the alkene (forming the CH,BrCF,* radical), and subsequent abstraction of a second bromine atom from Br, by this radical was ded~ced.~' The mechanisms of the reactions between CF, and NO and between CF and NO have been investigated, using mass spectral and chemical laser emission techniques. The former reaction gives a preponderance of CF20, with much smaller (but significant) amounts of FCN, whereas these two products are formed in approximately equal amounts in the latter reaction.72 The biradical CF, has been identified in CH4-02-Ar flames initially containing <l % CF,Br, burning at 0.04 atm. It was suggested that CF, is formed principally by the reaction CF, +H + HF+CF,. The decay of CF, is via reactions with the major flame radicals.73 A detailed study of the formation of C g ions from c2F6 has been undertaken by photoelectron-photoion coincidence spectrometry. All C g ions observed are apparently formed by the primary dissociation of molecular ions.74 The mass spectroscopic method has been used to study the photodissocia- tion of CF31 and C,F,I,75 and also to determine appearance potentials, heats of formation, and photoionization effects of the ions CFCll, CCl;, CFCl', and CCll from CFCl,, of the ions CF,Cl,f, CFCl,', CFCl', and C g from CF,Cl,, and of the ions CF3Cl+, CF;, and CF,' from CF,C1.76 The reaction between PPh, and CCl, has been investigated in depth. The first isolable intermediate product is " M. T. Bowers and M. Chau, J. Phys. Chem., 1976, 80, 1739. 66 I. B. Goldberg and G. R. Schneider, J. Chem. Phys., 1976, 65, 147. 67 R. G. Manning and J. W. Root, J. Chem. Phys., 1976, 64, 4926. E. C. Wu and A. S. Rodgers, J. Amer. Chem. SOC., 1976, 98, 6112. 69 F. J . Dillemuth, B. D. Lalancette, and D. R. Skidmore, J. Phys. Chem., 1976, 80, 571. 70 F. S. Toby and S. Toby, J. Phys. Chem., 1976, 80, 2313. 71 J. M. Pickard and A. S. Rodgers, J. Amer. Chem. Soc., 1976, 98, 6115. 72 T. L. Burks and M. C. Lin, J. Chem. Phys., 1976, 64, 4235. 73 J. C. Biordi, C. P. Lazzard, and J . F. Papp, J. Phys. Chem., 1976, 80, 1042. 74 I. G. Simm and C. J. Danby, J.C.S. Faraday 11, 1976, 72, 860. 75 V. L. Tal'roze, N. N. Larichev, I. 0. Leipunskii, and I. I. Morozov, J. Chem. Phys., 1976,64,3138. 76 J. M. Ajello, W. T. Huntress, and P. Rayermann, J. Chem. Phys., 1976, 64, 4746. 116 Inorganic Chemistry of the Main-Group Elements [Ph,PCCl,]' Cl-. This then reacts with the remaining phosphine very quickly to give, via the short-lived intermediates Ph3P=CC12 and Ph3PC12, the stable product [Ph,P=C(Cl)=PPh,]' Cl-.77 The unstable product found in the chlorina- tion of formic acid has been identified by microwave spectroscopy as formyl Oxygen and Sulphur Derivatives. Carbon suboxide has been obtained in 54% yield by the thermolysis of bis(trimethylsily1)malonate in the presence of P,O, at ca. 160 0C.79 A number of rare-earth intermetallics have been shown to be active catalysts for the reaction between CO and H, to form methane, For example, LaNi, catalyses the reaction of CO+ 3H, at 381 "C to give 95% conversion into CH,.80 A galvanic cell that includes a calcia-doped zirconia solid oxide electrolyte has been investigated in an attempt to determine more accurately the standard Gibb's free energy changes for the reactions (1) and (2).81 C (graphite) + CO, (g) + 2CO (g) (2) A small anomaly in the heat capacity at ca. 18 K when a-CO is annealed at 15-16K for 2040h, together with a relaxation phenomenon observed be- tween 14 and 19 K, have been interpreted as being due to a glass transition, from freezing, of molecular head-to-tail reorientation." Rapid rates of vibrational energy transfer at room temperature have been observed for energy transfer from CO (Y = 1) to the coupled 0, (200), 03(101), and 03(002) levels. Very rapid transfer also occurs from the coupled 0, (001) and 0, (100) levels to the OCS (020) Quenching of the 0 ( I D) atom by CO (Y = 0) has been studied by means of a flash-photolytic CO-laser resonant absorption method. The results indicate that the quenching reaction takes place via a CO, complex in which the electronic energy carried by the O(l D) atom has been completely randomized among all the vibrational modes of the CO, complex.84 Rate coefficients for the bimolecular and termolecular charge-transfer reactions of He: with CO, C02, and CH, have been meas~ired.'~ The CO,' ion has been produced by two methods: by the ion-molecule reaction 0; + CO-, CO: + 0," and also by collision of the inert-gas ions He+, Ne', Ar', and Kr' with C02.87 Crossed ion-neutral beam techniques have been employed to investigate the reactions of the ions C' and 0' with CO,. The former reaction produces CO' and CO, whilst the latter follows two alternative courses to 77 R. Appel, F. Knoll, W. Michel, W. Morbach, H. D. Wihler, and H. Veltman, Chem. Ber., 1976,109, 78 H. Takeo and C. Matsumura, J. Chem. Phys., 1976, 64, 4536. 79 L. Birkofer and P. Sommer, Chem. Ber., 1976, 109, 1701. '" V. T. Coon, T. Takeshita, W. E. Wallace, and R. S. Craig, J. Phys. Chem., 1976, 80, 1878. '* T. Atake, H. Suga, and H. Chihara, Chem. Letters, 1976, 567. 83 K. K. Hui and T. A. Cool, J. Chem. Phys., 1976, 65, 3536. R4 R. G. Shortridge and M. C. Lin, J. Chem. Phys., 1976, 64, 4076. '' F. W. Lee, C. B. Collins, and R. A. Waller, J. Phys. Chem., 1976, 65, 1605. 86 J. M. Ajello, J. Chem. Phys., 1975, 63, 1863. 87 W. Sim and M. Haigh, J. Chem. Phys., 1976, 65, 1616. 58. S. K. Das and E. E. Hucke, Carbon, 1976, 14, 235. Elements of Group IV 117 produce either O+CO,' or O,'+CO.'* The kinetics of the reaction of CO, with H, behind reflected shock waves have been investigated. The HCO radical was detected as an intermediate." The flowing afterglow technique has been used to determine the positions of equilibrium of the proton-transfer reactions (3) and (4).90 N2H+ + CO, XeH+ + CO, CO,H+ + N, CO,H+ + Xe (3) (4) Rates of dissociation of CO, have been measured in a r.f. discharge. The mechanism of dissociation probably involves vibrationally excited molecule^.^^ The amount of atomic oxygen produced by the reaction of CO, with active nitrogen has been measured by resonance absorption in a discharge flow system at 300 K. The initial production rate of atomic oxygen was found to be second-order with respect to the concentration of atomic nitrogen, and the effective termolecu- lar rate constant for the process varies inversely with CO, concentration. The results have been analysed in terms of a mechanism in which CO, is dissociated by an energetic species of N, formed by recombination of nitrogen atoms, possibly N,(A3X:) in high vibrational Ab initio vertical spectra and linear-bent correlation diagrams for the valence states of CO,, CO:, and CO, have been reported. Ground-state quadrupole moments were also Negative-ion products resulting from collisions between orthogonal beams of alkali-metal atoms (N, K, or Cs) and linear triatomic molecules C02, COS, and CS, have been studied from threshold to ca. 400eV. Electron affinities (CO,, -0.60 f 0.2; COS, 0.46 f 0.2; CS,, 1.0 f 0.2 eV) were evaluated from meas- urements of the threshold for the ion-pair production reactions.94 Cross-sections for the formation of various secondary ions by endoergic collisions of I- on CS, and COS have been investigated. With I- ions having kinetic energies up to 100 eV, only the secondary ions S- and IS- are observed in the case of CS,. With COS, the secondary ions S-, ICO-, and 0- are The reactions of 0 ( 3 P) atoms with CS, and CS have been studied by the technique of arrested-relaxation i.r. chemiluminescence. Emissions from the products CS, SO, and CO were observed from the reaction between 0 and CS,. The CO product channel of the O+CS, reaction was shown to be active, and displays a vibrational population distribution that has two maxima. Models have been proposed to account for this population di stri b~ti on.~~ A vapour-phase electron-diffraction study of 1,2-bis(trifluoromethyl)dithiete (1) has confirmed the dithiete structure. The CF3 groups are ~emi-staggered.~~ The " J. A. Rutherford and D. A. Vroom, J. Chem. Phys., 1976, 64, 3057. " J. M. Brupbacher, R. D. Kern, and B. V. O'Grady, J. Phys. Chern., 1976, 80, 1031. '" F. C. Fehsenfeld, W. Lindlinger, H. I. Schiff, R. S. Hemsworth, and D. K. Bohme, J. Chem. Phys., 'I P. Capezzuto, F. Gamarossa, R. d'Agostino, and E. Mohriari, J. Phys. Chem., 1976, 80, 882. 92 W. T. Rawlins and F. Kaufman, J. Chem. Phys., 1976, 64, 1128. 93 W. B. England, B. J. Rosenberg, P. J. Fortune, and A. C. WaN, J. Chem. Phys., 1976, 65, 684. 94 R. N. Compton, P. W. Reinhart, and C. D. Cooper, J. Chem. Phys., 1975, 63, 3821. 95 K. M. A. Refaey, J. Chem. Phys., 1976, 65, 2002. '' J. W. Hudgens, J . T. Gleaves, and J. D. McDonald, J. Chem. Phys., 1976, 64, 2528. 97 J. L. Hencher, Q. Shen, and D. G. Tuck, J. Amer. Chem. Soc., 1976, 98, 899. 1976, 64, 4887. 118 Inorganic Chemistry of the Main-Group Elements crystal structures of Cs,(S,C~C0,),CsCl,H,098 and K,(S,C*COS),KClg9 have been determined. The two thio-oxalate ions possess, to a very good approximation, C,, and C, symmetry, respectively, both having mutually perpendicular carboxylate groups. Other Derivatives. The structures of the nitromethane derivatives C(N02)4100 and HC(NO,),, ClC(NO,),, and BrC(NO,),lO' have been determined by electron diffraction. Both the thermal and photochemical decompositions of methyldi-hide in the gaseous phase have been studied. Both decompositions yield CH, and N, in equal amounts, and proceed by a radical chain mechanism with $order kinetics, propagated by the reactions CH,+CH,N,H + CH,+CH,N, and CH,N, + CH3+N2.102 2 Silicon, Germanium, Tin, and Lead Hydrides of Silicon, Germanium, and Tin.-The hydrogen-atom-initiated decom- position of SiH, at room temperature produces mainly H2, Si,H6, and a solid deposit, with trace amounts of Si3H8 and Si,H,, appearing later as secondary products. The initial reaction appears to be nearly completely described by gas-phase conversions of SiH, into Si2H6 and H,. The secondary gas-phase reactions are strongly influenced by surface reactions involving silicon hydride polymer. Detailed studies of the H-D distribution in the disilane product of an equilibrium mixture of SiH, and SiD, show that the disilane is formed by insertion of SiH,, SiHD, and SiD, into SiH4 and SiD4, and that the combination of SiH, and SiD, radicals plays virtually no ro1e.'03 The gas-phase kinetics of the reactions of H-, D-, OH-, -C-, -Cg, -CT, and C,H- with SiH, have been investigated at 297 K, using flowing afterglow techniques. The reactions are characterized by a variety of channels and reaction efficiencies. The rate constants measured for the reactions of H- and D- with SiH, are in accord with the formation of SiHT as a reaction intermediate.'04 Studies of the reaction of C E and SiH, in the gaseous phase show that extensive redistribution of F and H takes place between C and Si centres, which must occur within a single collision complex.1o5 The kinetics of the gas-phase reactions of iodine with C1,SiHlo6 and q8 R. Mattes and W. Meschede, Chem. Ber., 1976, 109, 1832. q9 W. Meschede and R. Mattes, Chem. Ber., 1976, 109, 2510. loo N. I. Sadova, N. I. Popik, and L. V. Vilkov, J. Mol. Structure, 1976, 31, 399. '"' N. I. Sadova, N. I. Popik, and L. V. Vilkov, J. Shuct. Chem., 1976, 17, 257. S. K. Vidyarthi, C. Willis, and R. A. Back, J. Phys. Chem., 1976, 80, 559. ln3 E. R. Austin and F. W. Lampe, J. Phys. Chem., 1976, 80, 2811. I o4 J . D. Rayzant, K. Tanaka, L. D. Betowski, and D. K. Bohme, J. Amer. Chem. SOC., 1976,98,894. lo5 J . R. Krause and F. W. Lampe, J. Amer. Chem. SOC., 1976, 98, 7826. R. Walsh and J . M. Wells, J.C.S. Faraday I, 1976, 72, 1212. Elements of Group IV 119 Me,SiH'07 have been investigated. Both reactions proceed via an abstraction step I- + X,SiH + X,Si* +HI, giving X3SiI and HI as the products. Small quantities of H2 are also observed with C1,SiH. Low-energy photoelectron spectra for the silanes Si,H2n+2 (n = 1-5) have been reported."' Vapour-phase Raman spectra for the hydrides MH, (M=C, Si, Ge, or Sn) have been measured at pressures of 0.5-1.0 atm at ca. 295 K, and the intensities of all four Raman-active fundamen- tals of each molecule have been determined relative to that of the v,(a,) band of methane as the external ~tandard.'~' The valence electronic structures of H,XYH, (X,Y=C, Si, or Ge) molecules have been determined by non-empirical calcula- tions, using a pseudopotential method within the S.C.F. approximation. Barriers to internal rotation were also calcu1ated.'l0 Methyl-lithium reacts with Y(SiH,), (Y =O, S, or Se) or Z(SiH,), ( Z=P or As) in ether to give Li(YSiH,) or Li[Z(SiH3)]2. (H3Si),N does not react cleanly with MeLi to form an analogous compound. N.m.r. spectra of solutions containing both LiYSiH, and Y(SiH3)2 show that exchange occurs that is rapid on the n.m.r. time-scale unless Y is 0. Silyl selenoacetate has been prepared by allowing Li(SeSiH,) to react with MeCOC1.lll Silatrane, HSi(OCH2CH2)3N, has been shown to have potential as a reducing agent for some types of organic compounds, including halides, carbonyl compounds, and azoxybenzene.'" Infrared, tin-l19m Mossbauer, and 'H n.m.r. data for triorganotin hydrides and diorganotin dihydrides have been interpreted in terms of weak intermolecular association in the neat state or in solution in non-donor solvents and complex formation in donor Tritium isotope effects on the transfer of hydrogen atoms from R3SnH to alkyl radicals have been reported. Although the isotope effects generally increase as the bond strength of the new CH bond decreases, the correlation with bond strength is poor.115 The thermal decom- position of Bu,SnFH at 100 "C yields FBu,S~S~BU,F,"~ whilst Bu,SnClH and Bu2Sn0 undergo exchange of the functional group to give Bu,SnH, and C ~B U ~S~OS~B U ~C ~. ~ l7 The Metal(rv) Oxides and Related Oxide Phases.-SimpZe Oxi des. By far the majority of work published during the past year refers to studies of adsorption phenomena on silica and tin(Iv) oxide. Infrared spectroscopy is the most popular technique for the study of such systems. Solid-vapour phase studies with silica continue to yield much new data. Isocyanates chemisorb on hydroxyl sites of silica to give urethane species, but physisorption and trherization of the isocyanate also occur.'18 Three distinct surface species are formed on the surface of silica lo7 R. Walsh and J . M. Wells, J.C.S. Faraday I, 1976, 72, 100. lo' H. Bock, W. Esslin, F. Feher, and R. Freud, J. Amer. Chem. Soc., 1976, 98, 668. lo9 R. S. Armstrong and R. J. H. Clarke, J.C.S. Faraday U, 1976, 72, 11. 'lo G. Nicholas, J. C. Barthelat, and Ph. Durand, J. Amer. Chem. Soc., 1976, 98, 1346. ' I 1 S. Cradock, E. A. V. Ebsworth, D. W. H. Rankin, and W. J . Savage, J.C.S. Dalton, 1976, 1661. 'I2 M. T. Attar-Bashi, C. Eaborn, J. Vencl, and D. R. M. Walton, J. Organornetallic Chern., 1976,117, '13 V. A. Ivanov, V. 0. Reikhsfel'd, and I. E. Saratov, J. Gen. Chem. (U.S.S.R.), 1976, 45, 1999. 'I4 V. 0. Reikhsfel'd, V. A. Ivanov, and I. E. Saratov, J. Gen. Chern. (U.S.S.R.), 1976, 45, 2202. '15 S. Kozuka and E. S. Lewis, J. Amer. Chem. Soc., 1976, 98, 2254. '16 A. K. Sawyer, W. B. Ewert, and G. M. Brissey, Synth. React. Inorg. MetaI-Org. Chem., 1976,6,337. '17 A. K. Sawyer, J. E. Brown, S. L. Fredrickson, and G. A. Scott, Synth. React. Inorg. Metal-Org. 'la A. Guiller, M. Coudurier, and J . B. Donnet, Bull SOC. chim. France, 1975, 1563. C87. Chem., 1976, 6, 281. 120 Inorganic Chemistry of the Main-Group Elements after treatment with gaseous HCN or C,N, at high temperatures, and calculations of force constants combined with experimental isotopic shift data have indicated that these are a silyl isocyanate, a silyl cyanide, and a silyl isocyanide. A fourth species is unique to the C,N, reaction when very high temperatures are employed, and its identity is unknown. The surface SiCN and SiNC species are converted into SiNCO after heating in oxygen. Acetonitrile behaves like HCN in its reaction with silica, and gaseous methane is a product of the reaction.ll' Another in-depth study involves methyl fluorosulphate.120 In this system, it has been established that isolated surface silanol groups are hydrogen-bonded to the oxygen atoms of sulphuryl groups in adsorbed MeS0,F. Subsequent slow chemisorption reactions occur, and generate the surface species SiOMe, SiF, SiOSO,OMe, and SiOS0,H. The presence of hydrophobic SiOMe groups reduced the ability of the oxide to adsorb water. However, replacement of the SiOMe by SiF groups increased the ability of the oxide to adsorb water, and in some situations gave a surface which adsorbed more water at high vapour pressures than did untreated silica. Complete dehydroxylation of silica by treatment with MeS0,F at 305 K followed by evacuation at ca. 853 K gave a hydrophobic surface. Surface silanol groups are considered to be the primary adsorption sites on partially fluorinated silica. The presence of SiF groups enhances multilayer adsorption of water on the primary adsorption sites. Gaseous ammonia is chemisorbed on silica at 650 "C as a surface SiNH, group.121 Studies of the chemisorption of H20, NH,, and MeOH on highly dehydroxylated silica have provided evidence that the reactive site corresponds to a siloxane-type site which forms when the degassing temperature under vacuum is >400 OC.12, The hydrogen-bonding properties of surface hydroxy-groups of silica gel have been studied by following the adsorption of a series of organic com- pounds which are weak hydrogen-bond acceptors and observing the OH stretching frequency.123 Water-derived impurities in the form of SiOH groups have been detected by Raman spectroscopy in Suprasil-1 , a fused synthetic silica. Two components of the OH band were observed, indicating that there are two classes of OH interactions in the fused silica.124 Surface OH groups on silica may be esterified by CF,CH,OH. Without a catalyst, only 35% of SiOH groups are esterified at 30°C after three hours, but with NH, (0.2Torr) as a catalyst, 98% were esterified, suggesting thatathe extraction of a proton from the OH group of the alcohol by NH, contributes to the esterification. The esterfied silica is hydrophobic, but is hydrolysed in the presence of water.125 The adsorption of Zn", Cd", and Hg" complexes with the p-dhethylaminoanil of methylglyoxal on silica gel has been studied."' The e.s.r. spectra of naturally abundant "SiH, and ,'SiD, radicals produced by y-irradiation of silanes adsorbed on the surface of silica gel have been rec~rded,'~' as have the I3C chemical shifts of all of the isomeric 'Iy B. A. Morrow and I. A. Cody, J.C.S. Faraday I , 1975, 71, 1021. 12" D. D. Eley, G. M. Kiwanuka, and C. H. Rochester, J. C. S. Faraday I, 1975, 71, 2340. 12' B. A. Morrow, I. A. Cody, and L. S. M. Lee, J. Phys. Chem., 1975, 79, 2405. 122 B. A. Morrow and I. A. Cody, J. Phys. Chem., 1975,79, 761. 123 R. E. Sempels and P. G. Rouxhet, Bull. SOC. chirn. belges, 1975, 84, 361. lZ4 G. E. Walrafen, J. Chem. Phys., 1975, 62, 297. 126 W. U. Malik, R. C. Saxena, S. C. Maheshwari, and R. K. Upadhyay, Indian J. Chern., 1974,12,768. 12' T. Katsu, Y. Yatsurugi, M. Sato, and Y. Fujita, Chern. Letters, 1975, 343. K. Tsutsumi, H. Emori, and H. Takeshita, Bull. Chern. SOC. Japan, 1975, 2613. Elements of Group IV 121 butenes adsorbed on silica.’*’ Siloxene, (S&,O3H&, a unique solid with a high surface area that contains reactive SiH groups, can isomerize n-butenes via hydrogen-deficient sites, as shown in Scheme l .I 2” The effect of the Ni: Sn ratio of Scheme 1 Ni-Sn catalysts supported on silica on the dehydrogenation of cyclohexanone to phenol, of cyclohexylamine to aniline, and of cyclohexane to benzene has been investigated. The optimum catalyst composition for each had a Ni: Sn ratio of 2.5, 8, and 10, respectively. Metallic nickel and @-tin, as well as the alloy phases Ni3Sn,, Ni,Sn,, and NiSn, were observed on the catalyst by X-ray diffraction studies, but molten tin exists on the catalyst at temperatures > ca. 230 “C. The effect of the addition of tin seems to be the moderation of the strong adsorption of the polar substrate on the Ni-silica surface.’3o A number of papers describe adsorption onto the silica surface from the liquid phase. The adsorption of phenol onto silica immersed in CC1, has been studied by i.r. spectroscopy. Isolated hydroxy-groups on the oxide surface form hydrogen bonds with adsorbed phenol molecules. The combined adsorption isotherms and spectroscopic results enabled an estimate to be made of the population of isolated hydroxy-groups on the sample of silica studied. Infrared studies of the adsorp- tion of the methyl esters of a series of n-fatty acids at silica1 benzene and silica I CCl, interfaces show that, regardless of whether the solid surface carries only isolated silanol groups or these and hydrogen-bonded silanol groups, it is only the former species which act as adsorption centres. From each solvent, the adsorbed molecules are held by hydrogen-bonding between the carbonyl group of the ester and the surface silanol Adsorption and heats of adsorption134 for the same systems have also been reported. The i.r. technique has also been applied to the study of tin(rv) oxide. Hexa- chloroacetone is oxidized during chemisorption to produce a surface trichloroace- tate, whereas nitriles are converted into surface acetimidato-anions, which may be converted into the corresponding carboxylates by heating in vacuo and may be hydrolysed by water vapour at 320K to the corresponding amides.13’ The reaction of surface hydroxy-groups with Me,SiCl and Me,SiCl, produces surface Sn-siloxy-species. At higher temperatures, attack of the oxide bulk occurs, and a silicone polymer is formed in the case of Me2SiC12.’36 Treatment of the tin(rv) oxide with a chlorosilane has the effect of ‘drying’ the surface, by removing 12’ I. D. Gray and J. F. Kriz, J. Phys. Chem., 1975, 79, 2145. 129 Y. Ono, Y. Sendoda, and T. Keii, J. Amer. Chem. SOC., 1975, 97, 5284. I3O M. Masai, K. Mori, H. Muramoto, T. Fujiwara, and S. Ohnaka, J. Catalysis, 1975, 38, 128. 13’ K. Marshall and C. H. Rochester, J.C.S. Faraday I, 1975, 71, 2478. 13’ A. K. Mills and J. A. Hockey, J.C.S. Faraday I, 1975, 71, 2398. 133 A. K. Mills and J. A. Hockey, J.C.S. Faraday I, 1975, 71, 2384. 134 A. K. Mills and J. A. Hockey, J.C.S. Faraday I, 1975, 71, 2392. 135 P. G. Harrison and E. W. Thornton, J.C.S. Faraday I, 1976, 72, 2484. 13‘ P. G. Harrison and E. W. Thornton, J.C.S. Faraday I, 1976, 72, 1310. 122 Inorganic Chemistry of the Main-Group Elements molecular water at ambient temperature and leaving isolated surface OH groups. The reaction of such single OH groups with ethyl isocyanate results in the formation of a surface urethane. The chemisorption is reversed at high tempera- tures. Adjacent OH groups react to give a 1,3-diethylurea adsorbate as a perturbed 'carboxylate-type complex'. Phenyl isocyanate also forms a urea and a urethane, which may be desorbed by evacuation at 320 K.13' The propene-D,O and isobutene-D,O exchange reactions have been investigated in order to clarify the initial hydrogen-abstraction stage of the catalytic oxidation of propene to acrolein on a range of mixed SnIv-Sbv oxide catalysts. The propene-D,O exchange reaction at 473 K proceeds stepwise, and the formation of a symmetrical ally1 intermediate is indicated on pretreated catalysts, but a carbonium ion species was formed in the absence of pretreatment. The formation of either intermediate is consistent with the observation that the exchange is limited to five of the hydrogen atoms of the propene. Stepwise exchange of all eight of the hydrogen atoms of isobutene is found at 323 K, and probably involves a carbonium ion species. The oxygen-addition stage of the oxidation has been examined by the use of l 8 0 either in the gaseous or the catalyst phase. The percentage of C,H,I6O in the total amount of acrolein formed at 573K in propene-'"O, mixtures is initially very high, but decreases as the reaction proceeds, indicating that the oxygen in acrolein is provided by the lattice, which is subsequently re-oxidized by oxygen in the gaseous phase. The l60 content of the CO, formed also decreases as the reaction Needle-shaped crystals of SnO, have been grown from a melt of B203,V205 containing Zn,SO,. The direction of growth is along the c-axis.l4' Silicates, Germanates, and Related Materials. Forsterite (2MgO,SiO,) is formed at low temperatures by heating (1400 "C, 5 h) the mixed powders prepared by the simultaneous hydrolysis of magnesium and silicon al k~xi des.~~' Two new phases have been isolated from the Er,O,-PbO-SO, system; these are Er6Pb3(Si04)6 and Er,PbSi,O,,, both as single crystals. The former phase is hexagonal, and has an 'apatite-like' structure, with isolated SiO, tefrahedra.l4' A determination of the crystal structure of the phase Na2O,Si0,,8H,O shows that its composition is actually Na,(H,SiO,) ,7H20, thus resembling other members of the series Na,O,SiO,,nH,O in containing isolated tetrahedral [(HO),SiO,]'- groups.'43 The structures of the silicate anions in the crystal modifications T-Pb2Si04, M,- PbSiO,, and H-Pb,SiO, have been studied. T-Pb,SiO, contains anions of the type [Si,O,]"-, with, additionally, [Si,,O,,]"- and [SiO,]"- anions. M2-PbSiO, is inter- mediate between M1-Pb2Si04, which contains tetrameric [Si,O,,]"- ring anions, and H-Pb,SiO,, whilst this latter material is a p~l ysi l i cate.~~~ Crystals of sorensen- ite, Na,SnBe(Si30,),,2H,0, consist of infinite (Si309).. chains along [OlO], and 13' P. G. Harrison and E. W. Thornton, J.C.S. Furuduy Z, 1976, 72, 1317. 13' J. R. Christie and D. Taylor, J.C.S. Faraday I, 1976, 72, 334. 139 P. Pendleton and D. Taylor, J.C.S. Faruduy I, 1976, 72, 1114. 140 S. Shimada, K. Kodaira, and T. Matsushita, Chern. Letters, 1976, 235. 14' 0. Yamaguchi, Y. Nakajima, and K. Shimizu, Chern. Letters, 1976, 401. 1 4 ' G. B. Ansell and B. M. Wanklyn, J.C.S. Chern. Comm., 1976, 706. 143 L. S. Dent Glasser and P. B. Jamieson, Actu Cryst., 1976, B32, 705. 144 J. Gotz, D. Hoebbel, and W. Wieker, Z. unorg. Chern., 1975, 418, 29. Elements of Group IV 123 thus this belongs to the wollanstonite mineral group. The tin atoms are octahed- rally co-ordinated by oxygen atoms from four silicate chains.145 Bent silicate chains linked by three kinds of copper and two kinds of sodium atom are present in crystals of the synthetic copper sodium silicate CU,N~,(S~,O,~).~~~ Crystals of nambulite, (Li,Na)Mn,Si,O,,(OH), are triclinic, having infinite silicate chains with a repeat unit of five tetrahedra and manganese polyhedral bands, both parallel to [110]. Nambulite is more closely related to baringtonite, Ca2Fe1'Fe111Si,014(OH), than to thodonite, CaMn,Si,O,,, in the arrangement of the silicate chains and polyhedral bands. 147 A crystalline and acid-soluble silicate of composition Co20,,6en,7.2SiO2,26H2O has been obtained by the reaction of a cobalt ethylenediamine hydroxide solution with Si(OMe),. The material has been shown to be an acid double four-ring silicate of formulation [co(en),],(H2si8o2,), 16-28H20.148 A novel silicate type, consisting of the dou- ble five-ring anions (Sil0O2J1'-, has been identified in crystalline silicate mixtures in the systems Bu4NOH-SiO2-H20 and (i-C,Hll),NOH-Si0,-H20. The corres- ponding trimethylsilyl ester, (Me3Si)l,,(Sil,,025), has also been ~ynthesized.'~~ The vibrational spectra of silicates and germanates AB"'X0, (A=Li or Na; B"'=lanthanon; X=Si or Ge) with an olivine structure have been st~died.'~' Vibrational and visible spectra of synthetic tephroite, Mn,SiO,, show that the Raman-active components of the internal modes of the Si0;- anions do not appear to interact with the motions of the Mn2+ions, but the i.r. components of v2 and v4 appear to be highly mixed with the external modes of the manganese 1atti ~e.l ~~ Three vibrational studies of silicates and germanates with the benitoite structure have been published. A single-crystal vibrational study of benitoite itself, BaTiSi,O,, has been undertaken. The crystal is non-centr~symmetric.~~~ Infrared spectra of solid solutions between silicates and germanates with the benitoite structure have been compared with data for 'pure' Si,O, and Ge,O, rings to investigate the possible existence of the mixed rings Si,GeO, and Ge,SiO,. These species were identified by the two characteristic bands in the region 650-670~m-~ that are missing from the spectra of the two symmetrical rings. These bands were shown to be due to silicon- and germanium-containing vibrations from a study of the 28Si-30Si and 70Ge-76Ge isotopic shifts (7 and 4 cm-l, respectively), and they correspond to v(M0M;) of the MMaO, rings. An evaluation of the experimental distribution of all four types of ring is in good agreement with a random distribution of silicon and germanium.153 Vibrational spectra of cyclic silicates and germanates with the benitoite, wadeite, and tetrager- manate structures have also been reported,ls4 as have Raman spectra of binary alkali-metal silicate glasses and The glasses studied had a composition 14' J. Metcalf-Johansen and R. G. Hazell, Acta Cryst., 1976, B32, 2553. 146 K. Kawamura and A. Kawahara, Acta Cryst., 1976, B32, 2419. 1 4 ' D. Hoebbel, W. Wieker, J. I. Smolin, J. F. Sepelev, and R. Pomel, Z. anorg. Chem., 1976,423,225. 149 D. Hoebbel, W. Wieker, P. Franke, and A. Otto, 2. anorg. Chem., 1975, 418, 35. M. Th. Paques-Went, Spectrochim. Acta, 1976, 32A, 383. lS1 H. D. Stidham, J. B. Bates, and C. B. Singh, J. Phys. Chem., 1976, SO, 1226. lS2 D. M. Adams and I. R. Gardner, J.C.S. Dalton, 1976, 315. lS3 J. Choisnet, A. Deschampes, and P. Tarte, Spectrochim. Acta, 1976, 32A, 57. 154 J. Chok.net, A. Deschampes and P. Tarte, Spectrochirn. Acta, 1975, 31A, 1023. 15' S. A. Brawer and W. B. White, J. Chem. Phys., 1975, 63, 2421. H. Narita, K. Koto, N. Morimoto, and M. Yoshii, Acta Cryst., 1975, B31, 2422. 147 124 Inorganic Chemistry of the Main -Group Elements M,O,xSiO, ( 1 ~ x S 4 ; M=Li, Na, or K). A strong resemblance between the glassy and crystalline spectra was observed, consistent with a considerable amount of structural disorder in the glass. Crystals of Li,ZnGeO, are built up of (GeO,) tetrahedra linked by (LiO,) and (ZnO,) tetrahedra.156 y-Li,GeO, and Mg2Ge0, (olivine) have the same hexa- gonal compact packing of oxygen atoms. A single-crystal study of Li,MgGeO, (high-temperature form) shows parenthood with Li,PO,. Mixtures of y-Li,GeO, and Mg,GeO, yield a limited solid solution Li,-,Mgx,2Ge04.157 The crystal structures of the feldspar modification BaGa,Ge,0,,158 of the paracelsian-like modifications of synthetic SrGa,Ge,O, and BaGa,Ge20,,'59 and of the tetrager- manates Rb,Ge,09 and Rb2TiGe30,160 have also been determined. Garrelsite, NaBa3Si2B,ol6(0H),, has a three-dimensional framework com- posed of silicoborate sheets and Ba-0 polyhedral layers, both running parallel to (001). The silicoborate sheets are of a new type, consisting of two types of alternating silicon and boron tetrahedral four-membered rings, the planes of which are normal to each other.161 In the dickite : formamide intercalate A1,Si205(OH),,HCONH, the formamide molecules lie near vacant sites in the aluminosilicate layers.162 Edingtonite, Ba,,,A1,.03Si,.,70,0,7.8 1H20, a rare zeol- ite, is othorhombic, with Si-A1 ordering of the same kind as found in natr01ite.l~' Crystals of @-&SiW12040,9H20 contain the @-SiW120:; anion, an isomer of the well-known Keggin ion a-SiW,,Oz;. The idealized Keggin ion has Td symmetry, but the p-isomer has only C, Crystals of OL - K ~S~W~~O~~, ~~H , O are cubic and contain discrete [SiWIlO3,]'- anions, which are almost identical to a-SiW,,O~, anions in shape and size, but with one tungsten atom and the exterior terminal oxygen atom Crystals of senaite, Pb,,,,Ti,,.6,Fe,.,,Mn,.~,O,,, from the Diamantina region of Brazil, have a structure based on a nine-layer close-packed array of anions, with lead atoms partially occupying one of thirteen sites in cubic layers.166 Emission spectra from polycrystalline samples of K13Eu'"(SiWl10,,)2,xH20 have been Direct microscopy has been employed to study the crystallization of zeolites in dilute solutions of sodium aluminosilicate at 70°C in the absence or presence of starting solid (gel or zeolite). The results show that the crystals of zeolite are formed in solution. In some experimental conditions, such crystals appear with no intermediate precipi- tation of a gel. When a sodium aluminosilicate gel is visible, it constitutes a reservoir of reagent, and nucleation is favoured by the presence of crystals of The composition and stability of thin oxide films ( G 35 A) grown 156 E. Plattner, H. Vollenke, and A. Wittman, Monatsh., 1976, 107, 921. B. Monnaye, Rev. Chinz. minerale, 1976, 13, 422. M. Calleri and G. Gazzoni, Acta Cryst., 1976, B32, 2733. lS9 M. Calleri and G. Gazzoni, Acta Cr yst ., 1976, B32, 1196. M. Goreaud and B. Raveau, Acta Cryst., 1976, B32, 1.536. S. Ghose, C. Wan, and H. H. Ulbrich, Acta Cryst., 1976, B32, 824. 157 16* J. M. Adams and D. A. Jefferson, Acta Cr y s t . , 1976, B32, 1180. 163 E. Galli, Acta Cryst., 1976, B32, 1623. 164 K. Y. Matsumoto, A. Kobayashi, and Y. Sasaki, Bull. Chem. SOC. Japan, 1975, 3146. 16' K. Y. Matsumoto and Y. Sasaki, Bull. Chem. SOC. Japan, 1976, 156. 166 I. E. Grey and D. J. Lloyd, Acta Cr y s t . , 1976, B32, 1509. 16' M. J. Stillman and A. J. Thompson, J.C.S. Dalton, 1976, 1138. 16' J. L. Guth, Ph. Caullet, and R. Wey, Bull. SOC. chim. France, 1975, 2375. Elements of Group N 125 thermally on Pb-In alloy substrates at room temperature and at various oxygen pressures have been studied quantitatively by Auger spectroscopy. The results indicate that all the oxide films are enriched in indium by varying amounts, depending on the alloy composition and the oxygen pressure. For alloys contain- ing more than 10 atom% of indium, the surface layer consists of pure I n203 only, whereas for alloys of lower indium concentration the oxide layer is composed of a mixture of PbO and h1203. ' ~~ Molecular Silicon (w)-, Germaniurn(rv)-, Tin(w)-, and Lead (w)-Oxygen Deriva- tives. The structures of Me,SiOSiMe3170 and MeSi(OMe),17' have been investi- gated by electron diffraction. The data for the former compound are consistent with a staggered conformation (C2v symmetry), whilst a model with twist angles around the Sn-0 bonds of ca. 30" cannot be excluded. The SiOSi bond angle in the disiloxane was deduced to be 148 f 3". The angle at oxygen in Ph3SiOPbPh3 is 142", but crystals of this compound are disordered, such that ca. 16% of molecules are reversed, i.e. lead atoms occupy silicon sites and vice versa.172 Carboxyethylgermanium sesquioxide, 03( GeCH2CH,C02H)2, has been prepared by the route shown in Scheme 2. Crystals obtained by recrystallization from water HGeC1, +CH,=CHCN - CI,GeCH,CH,CN - O,(GeCH,CH,CO,H), Scheme 2 H*O/H+ consist of infinite sheets. The basic unit is a twelve-membered ring made up of six germanium tetrahedra bridged by oxygen atoms. Carboxylate chains are arranged alternately above and below the germanium-oxygen network around the ring. The sheets are bound together vertically by hydrogen The structure of EtSn(OH)Cl,,H,O comprises a dimeric centrosymmetrk complex in which the two hydroxy-groups bridge tin atoms. Two chlorine atoms occupy neighbouring vertices about the octahedrally co-ordinated tin atoms (Figure l).174 Single L W Figure 1 The structure of EtSn(OH)Cl,,H,O (Reproduced by permission from Actu Cryst., 1976, B32, 923) 171 172 1 69 170 N. J. Chou, S. K. Lahiri, R. Hammer, and K. L. Komarek, J. Chem. Phys., 1975, 63, 2758. B. Csakvan, Z. Wagner, P. Gomory, F. C. Mijlhoff, B. Rozsondai, and I. Hargittai, J. Organometallic Chem., 1976, 107, 287. E. Gergo, I. Hargittai, and G. Schultz, J. Organometallic Chem., 1976, 112, 29. P. G. Harrison, T. J. King, J. A. Richards, and R. C. Phillips, J. Organometallic Chem., 1976, 116, 107. 173 M. Tsutsui, N. Kakimoto, D. D. Axtell, H. Oikawa, and K. Asai, J. Amer. Chem. SOC., 1976, 98, 8287. 174 C. Lecompte, J. Protas, and M. Devaud, Acra Cryst., 1976, B32, 923. 126 Inorganic Chemistry of the Main - Group Elements crystals of [CU(NH,),(H,O),][S~(OH)~] have been obtained by the reaction of CU(NO,)~,~H,O and K,Sn(OH)6 in aqueous ammonia, and have a structure consisting of infinite chains of alternating [Sn(OH),] and [Cu(NH,),(H,O),] octahedra linked parallel to the b-axis by common edges. Adjacent chains are linked by hydrogen The reaction of Cl,Sn(acac), with silver perchlorate in acetylacetone yields the ionic compound [Sn(acac),]ClO, as a crystalline solid. The derivative is stable in anhydrous acetonitrile at room temperature, but undergoes hydrolysis in the presence of a large amount of water in two steps: a fast initial reaction to give [Sn(acac)(OH)H20]C10,, which then slowly undergoes further hydrolysis or polymerization to give eventually a gelatinous precipitate. Ligand isotopic exchange with [14C]Hacac was also examined and found to be independent of the concentration of free H a~ac . ~~~ The crystal structures of three acylhydroxylamino-tin derivatives, vir. C1,Sn[ONPhC(0)Ph]2,'77 Me2Sn[ONHC(0)Me]2,'78 and Me,Sn[ONHC(O)Me],,- H20,17' have been determined. In all three derivatives the tin atom is six-co-cordinate, and the acylhydroxylamino ligands chelate the metal. The geometry of the chloro-tin derivative is nearly perfect octahedral, with cis chlorine atoms (Figure 2), and crystals are composed of non-interacting mole- Figure 2 The sfructure of Cl,Sn{ONPhC(O)Ph}, (Reproduced from J.C.S. Dulton, 1976, 1414) cules. In contrast, hydrogen-bonding networks link adjacent molecules in both the dimethyltin derivatives (Figure 3). Surprisingly, the stereochemistry in these two derivatives is vastly different. That of the monohydrate is severely distorted octahedral with a bent CSnC skeleton, similar to that in the previously reported Me2Sn[ONMeC(0)Mel2, whereas in Me2Sn[ONHC(0)Me], the two methyl groups occupy essentially cis positions (Figure 4). Me,Sn(edaa) [H,edaa = MV'- ethylenebis(acetylideneimine)], obtained from Me,Sn(NEt,), and H,edaa, was deduced to have a similar distorted trans octahedral ge~rnetry.''~ The geometries E. Dubler, R. Hess, and H. R. Oswald, 2. anorg. Chem., 1976, 421, 61. 17' A. Nagasawa and K. Saito, Bull. Chem. SOC. Japan, 1976, 49, 30'79. P. G. Harrison, T. J. King, and J. A. Richards, J.C.S. Dalton, 1976, 1414. 17* P. G. Harrison, T. J. King, and R. C. Phillips, J.C.S. Dalton, 1976, 2317. 179 P. F. R. Ewings, P. G. Harrison, and A. Mangia, J. Organometallic Chem., 1976, 114, 35. 177 127 (b) Mol ecul e ( 1 1 (a) Figure 4 ( a ) View of the stereochemistry of the tin atom in Me,Sn{ONMeC(O)Me},, illustrating the cis-octahedral configuration ; ( b ) View of the relative orientation of the two crystallographically independent molecules i n Me,Sn{ONMeC(O)Me},,H,O (Reproduced from J.C.S. Dalton, 1976, 2317) c24 Figure 5 Structure of Ph,Sn(sab) (Reproduced by permission from 2. anorg. Chem., 1976, 423, 7 5 ) 128 Elements of Group IV 129 of Me,Sn(acac),, Me,Sn(trop),, Me,Sn(oxin),, and their deuterio-analogues in carbon disulphide solution have been studied by i.r. spectroscopy. All three compounds exhibit two bands in the tin-carbon stretching region which shift ca. 5Om-’ upon deuteriation, indicating very strongly that a substantial amount of the cis octahedral isomer is present in solution in CS,. However, the spectrum of Me,Sn(acac), contains a third band which also shifts on deuteriation, which is assigned to the corresponding trans-isomer, showing that a mixture of isomers is present in this case.18o The co-ordination polyhedron about tin in Ph,Sn(sab) [sab = dianion of 2-hydroxy-N-(2-hydroxybenzylidene)aniline] is essentially that of a distorted trigonal bipyramid with nitrogen and carbon atoms in the equatorial plane (Figure 5) . No intermolecular association takes place as in Me,Sn(sab).’81 The crystal structure of chloromethylsilatrane has been determined, and shows a silicon-nitrogen interaction of 2.12 A.182 ‘H n.m.r. spectra of N-alkyl-5,Sdi-t- butyldiptychoxazstannolidines, Bu\Sn(OCH,CH,),NR, have been recorded at various temperatures in order to study the mechanism of dissociation-inversion. Activation parameters were estimated from the coalescence temperatures of the two But gr0~ps. l ~~ The tin-nitrogen bonds of amino-stannanes add across the carbonyl groups of Fe(CO), to yield novel stannyloxy-carbene complexes of iron, such as (2)-(5).18, M%N\ ,NM% X,SnO, ,/C==O, \;. , O’C. .;/ Sn \;“Fe(Co), \\ C---Fe(CO), (OC),Fe, Me , d / \o--/ \\ NMe, 7 Me,N (3) (2) X =Me or NMe, The tetrakis(acetat0)metal derivatives M(O,CMe), (M = Si, Ge, Sn, or Pb) have been prepared by the reaction of metal(Iv) halide with thallium acetate (M=Si, Ge, or Sn), or from red lead and acetic acid, all using acetic anhydride as the solvent. All react with potassium acetate to form K,[M(O,CMe),] complexes. The complexes K,[Sn(0,CMe)6](MeCO)20 and NMe,“Sn(O,CMe),] were also iso- lated.185 An X-ray study of the latter shows that crystals consist of discrete ions. R. B. Leblanc and W. H. Nelson, J. Organometallic Chem., 1976, 113, 257. H. F’reut, F. Huber, R. Barbieri, and N. Bertazzi, Z. anorg. Chem., 1976, 423, 75. la* A. A. Kemme, Y. Y. Bleidelis, V. M. D’yakov, and M. G. Voronkov, J. Stnrct. Chem., 1975,16,847. la3 A. Zschunke, A. Tzschach, and K. Jurkschat, J. Organometallic Chem., 1976, 112, 273. lE4 W. Petz and A. Jonas, J. Organometaflic Gem. , 1976, 120, 423. la5 N. W. Alcock, V. M. Tracy, and T. C. Waddington, J.C.S. Dalton, 1976, 2238. 130 Inorganic Chemistry of the Main-Group Elements C(222) O(252 1 Figure 6 Structure of the anion in “Me,]’ [Sn(O,CMe),]- (Reproduced from J.C.S. Dalton, 1976, 2246) The anions contain seven-co-ordinate tin in a pentagonal-bipyramidal arrange- ment. Two unidentate acetate groups occupy the axial sites, and the equatorial positions are occupied by two bidentate and one unidentate acetate groups (Figure 6).lS6 Infrared spectroscopy has been used to distinguish the different modes of bonding of acetate groups to metals. Thus, M(O,CMe), and K,[M(O,CMe),] (M = Si or Ge) were deduced to contain only unidentate acetate, Pb(O,CMe), only chelating acetate, K,[M(O,CMe),] (M = Sn or Pb) and NMe,[Sn(O,CMe),] both bridging and unidentate acetate, and Sn(O,CMe), sym- metrical and unsymmetrical chelating acetate.lS7 When (CH,=CH),Sn(O,CCF,), is warmed in CH2C12, CHC13, or CCl, and the solvent is partially removed, ‘ 0 F3 c F3 Figure 7 Structure of {(H,C=CH),Sn2(0,CCF,),0), (Reproduced by permission from Inorg. Nuclear Chern. Letters, 1976, 12, 859) la‘ N. W. Alack and V. M. Tracy, J.C.S. Dalton, 1976, 2246. N. W. Alack, V. M. Tracy, and T. C. Waddington, J. C. S. Dalton, 1976, 2243. Elements of Group IV 131 crystals of [(H,C=CH),Sn,(O2CCF,)zo], are produced. The structure of this material is shown schematically in Figure 7. The environment of each tin atom appears to be best described as a distorted trigonal bipyramid, with the tin atom bonded to two carbon and three oxygen atoms. Weak six-co-ordination is made up by an oxygen atom at either 2.66 or 3.12A. Half the trifluoroacetate groups function essentially as unidentate ligands and half as syn-anti(4) bridging ligands.ls8 Di~rgano-tin-adenine~~~ and -glycylglycinato-derivativeslgO have been prepared by the reaction of diorgano-tin dichloride with the appropriate anion, or from the oxide and glycylglycine in methanol. Mossbauer data indicate that (6) is the structure for the glycylglycinato-complexes. 0 (6) The thermal decomposition of lead titanyl oxalate tetrahydrate, PbTiO(C2H4),,4H20, in air or oxygen proceeds by initial dehydration in the temperature range 25-210 "C, followed by decomposition to the basic carbonate Pb,Ti,O,CO, at 210-375 "C, and final decarboxylation at 375-520 "C to give PbTiO,. This process is complicated in vucuo or in a non-oxidizing medium by partial reduction to lead(I1) oxide at the oxalate decomposition step. The forma- tion of free metallic lead affects the stoicheiometry of the intermediate carbonate, inhibits the evolution of CO, after decomposition of the carbonate, and yields a mixture of PbTiOs and titanium-rich PbTi30, as the final pr~ducts.'~~ The addition of hot DMSO to a solution of Ph,Sn(NO,), in anhydrous acetone yields the ionic complex [Ph,Sn(NO,)(DMSO),]' NO,, the structure of which is shown in Figure 8. Crystals are composed of discrete cations, in which the tin atom is seven-co-ordinate, and nitrate anions. The geometry of the cations is that of a distorted pentagonal bipyramid, with a bidentate nitrate group and the three DMSO ligands in equatorial sites and the two phenyl groups at the apices.lg2 Tri- phenyltin nitrate and triphenylphosphine oxide form a 1 : 1 adduct, whose struc- ture is shown in Figure 9. The two oxygen donors occupy the two axial sites of a trigonal bipyramid. 193 The structures of two phosphosilicate derivatives have been reported. Crystals of oxovanadium(w) diphosphatomonosilicate, VO(SiP,O,), are composed of V=O-V=O-V=O- chains lying along four-fold axes, with parallel Si(P04),Si(P04),Si chains. These chains are joined by oxygen atoms of the PO, groups which complete the distorted V06 0~tahedra.l ~~ I n (NH,),SiP,O, 3 , the Is* C. D. Garner, B. Hughes, and T. J. King, Inorg. Nuclear Chern. Letters, 1976, 12, 859. lS9 L. Pellerito, G. Ruisi, N. Bertazzi, M. T. L. Giudice, and R. Barbieri, Inorg. Chim. Acra, 1976,17, L9. 190 L. Pellerito, M. T. L. Giudice, G. Ruisi, N. Bertazzi, R. Barbieri, and F. Huber, Inorg. Chirn. Acta, lgl H. S. G. Murphy, M. Subba Rao, and T. R. N. Kutty, J. Inorg. Nuclear Chem., 1976, 38, 417. lg2 L. Coghi, C. Pelizzi, and G. PelizZi, J. Organometallic Chem., 1976, 114, 53. lg3 M. Nardelli, C. Pelizzi, and G. Pelizzi, J. Organometallic Chem., 1976, 112, 263. 194 C. E. Rice, W. R. Robinson, and B. C. Topfield, Inorg. Chem., 1976, 15, 345. 1976, 17, L21. 132 Inorganic Chemistry of the Main -Group Elements Figure 8 Structure of the cation in [Ph,Sn(NO,)(DMSO),]+ NO; (Reproduced by permission from J. Orgunornetullic Chern., 1976, 114, 53) two-dimensional SiP,O,, anion is built up from tetrapolyphosphate groups connected by silicon atoms in an octahedral co-~rdi nati on.'~~ Trimethyltin hypophosphite, Me,SnPO,H,, bis(trimethy1tin) phosphate hydrate, (Me3Sn),P0,H,2H,0, and bis(tripheny1tin) phosphate, (Ph,Sn),PO,H, have been obtained from the triorganotin chloride and aqueous solutions of the correspond- ing phosphorus oxy-acid. (Me3Sn),P0,H,2H,0 can be dehydrated in vacuo at 25 "C, but disproportionation occurs on heating. Tris(trimethy1tin) phosphatk, (Me,Sn),PO,, can be prepared from Me,SnCl and silver phosphate in methanol. Recrystallization from dioxan yields a idioxan solvate. The vibrational and Mossbauer spectra are consistent with trigonal-bipyramidal geometry for the tin atom in Me3SnP02H2, with bridging hypophosphite groups. The Mossbauer spectra for (Me,Sn),PO,H, (Ph,Sn),PO,H, and (Me3Sn),P0,H,2H,0 suggest that the two tin atoms are in similar, probably five-co-ordinate, environments. For (Me,Sn),PO,, vibrational and Mossbauer spectra are consistent with weakly associated structures in which the three tin atoms are all in similar environ- ment~. ' ~~ Triorgano-tin arylsulphonates and diorgano-tin bis(ary1sulphonates) 195 A. Durif, M. T. Averbuch-Pouchot, and J. C. Guitel, Acta Cr y s t . , 1976, 332, 2957. '96 T. Chivers, J. H. G. van Roode, J. N. Ruddick, and J. R. Sams, Canad. J. Chern., 1976,54,2184. Elements of Group IV 34 33 133 28 Figure 9 The structure of Ph,SnNO,,Ph,PO (Reproduced by permission from J. Orgunornetallic Chern., 1976, 112, 263) may be obtained in quantitative yield by the azeotropic dehydration of a mixture of organotin oxide and arylsulphonic acid in boiling benzene. Recrystallization of Me,SnO,SPh from methanol in air yields the monohydrate Me,SnO,Ph,H,O, whose structure is shown in Figure 10. Crystals are composed of five-co-ordinate Me,SnO,SPh,H,O units, weakly hydrogen-bonded together to form infinite parall- el chains. As usual, the oxygen-donor ligands occupy the axial The crystal structure of trimethyltin sulphinate, Me,SnO,SMe, is different. In this case the tin atoms are linked together via bridging methylsulphinate groups to form a helical chain along [loo); however, the geometry at the tin atom is very similar to that in the sulphonate mon~hydrate.~~~ Dimethyltin chromate may be prepared by allowing Me,SnCl, to react with silver chromate. Basic trimethyltin carbonate is obtained by slowly mixing an acetone solution of Me,SnCl, that has been saturated with CO, with potassium carbonate. The triphenyltin analogue is lq7 P. G. Harrison, R. C. Phillips, and J. A. Richards, J. Organometallic Chem., 1976, 114, 47. "* R. Hengel, U. Kunze, and J. Strahle, 2. anorg. Chem., 1976, 423, 35. 134 Inorganic Chemistry of the Main-Group Elements Figure 10 Projection of the unit cell of Me,SnO,Ph,H,O on the bc plane, showing the chains (Reproduced by permission from J. Organometallic Chem., 1976, 114, 47) obtained by slowly mixing methanolic solutions of Ph,SnCl, and caesium carbo- nate.lg9 In the complex Zn[Pb(10,),],6H20, the lead atoms are surrounded in a distorted octahedral fashion by oxygen atoms from six different iodate groups.2oo Halogen Derivatives.-Vapour-phase electron-diffraction studies of Si2F6,201 Me2AsF3,,02 Me2GeF2Y MeGeF,?O3 Me2GeBr2,,04 and MeGeBr3,04 have been carried out. The values for the barrier to internal rotation in Si2F6 were deter- mined to be either 0.51 or 0.73 kcalmol-', depending on the different assump- tions that were made of the temperature drop due to the expansion of gas in the nozzle. Attempts were made to calculate the potential barriers for Si2& (X = H, F, or Cl) molecules, using the CNDO/2 approximation. When silicon 3d orbitals are taken into account, the results differ widely from the experimental values for X = F and C1, but neglecting the contribution from the 3d orbital gave very good agreement between the theoretical and experimental potential barriers.201 Two microwave studies of MeGeH,F have been published. One, using three isotopic species, affords a value for the potential barrier of 940 f 30 cal mol-' and bond moments of the Ge-H and Ge-F bonds of 1.0 and 3.3 D, respe~tively.~~' The other, using twelve isotopic species, gives excellent agreement for the potential barrier (941 f 20 cal mol-' for MeGeH2F and 921 f 20 cal mol-' for MeGeD,F), as well as molecular structural parameters.206 The internal torsional modes in a of hydrogen-bonded molecules 199 R. G. Goel, H. S. Prasad, G. M. Bancroft, and T. K. Sham, Cunad. J. Chem., 1976, 54, 711. 201 H. Oberhammer, J. Mol. Structure, 1976, 31, 237. '02 H. Oberhammer and R. Demuth, J. Mol. Structure, 1976, 31, 1121. '03 J. E. Drake, R. T. Hemmings, J. L. Hencher, F. M. Mustoe, and Q. Shem, J.C.S. Dalton, 1976,394. J. E. Drake, R. T. Hemrnings, J. L. Hencher, F. M. Mustoe, and Q. Shem, J.C.S. Dalton, 1976,811. 205 L. C. Krisher and J. A. Momson, J. Chem. Phys., 1976, 64, 3556. 206 R. F. Roberts, R. Varma, and J. F. Nelson, J. Chem. Phys., 1976, 64, 5031. S. Zlonysh, H. Hartl, and R. Frydrych, Actu Cryst ., 1976, B32, 753. 200 204 Elements of Group IV 135 range of methyl Group IV metal halides have been determined from their inelastic neutron-scattering spectra, from which the potential barriers to internal rotation were cal ~ul ated.~~' The i.r. spectra of ClCH2SiC13-,Me, (n = 0-2) compounds in the liquid and crystal states and part of the Raman of the liquid state have been measured. From the data it was apparent that, for ClCH2SiC12Me and ClCH2SiClMe2, two rotational isomers coexist in the liquid state, whilst only one persists in the crystal. Solvent effects and the calculation of normal vibrations indicate that the gauche-form of ClCH2SiC12Me and the trans-form of ClCH2SiClMe2 are the isomers which persist in the crystal.20g Heats of formation, and heats of solution in 0.1 mol dm-3 FeC1, and 3 mol dm-3 HCl, for SnI, and SnI, have been determined.209 Si3F8 can be synthesized in good yield by treating Si,(OMe), with BF, in a sealed tube.210 Mono-organo-germanium trihalides may be obtained in fair yield by exchange between tetraorgano-tin compounds and germaniurn(rv) halide under y-irradiation from a 6oCo source.211 Organotin(rv) halides have been synthesized by the reaction of alkyl halides with both tin(I1) halides and tin metal. am-Dibromo-alkanes Br(CH,),Br (n 2 3) in 200-400% excess react readily with tin(I1) bromide to afford high yields of the monoinsertion product Br,Sn(CH,), Br, with only small amounts of the di-insertion product. Purification of the product by distillation is hampered by thermal degradation according to the reverse reac- tion.212 Alkoxy- and acyloxy-chloromethylsilanes also react with tin(I1) halides to yield the corresponding substituted silylmethyltin trihalides. Me3SiCH21 and tin(I1) chloride yield a mixture of the various combinations of chloride iodides Me,SiCH2SnC1,13-,, (n = 0-3), the compounds with n = 0 and 3 being the major products. 2-Chloroethyl- and 3-chloropropyl-tris(methoxy)silanes react much less readily with tin(I1) chloride, and only Me2SnC12 could be isolated in moderate yields. The alkoxy- and acyloxy-(chloromethy1)silanes also react with tin metal at 120-180 "C in the presence of a nitrogen-containing catalyst to afford analogous bis(silylmethy1)tin dichlorides in high yield.213 P-Substituted ethyltin trihalides may also be synthesized by the reaction of hydrogen halide with tin metal in the presence of a carbonyl-activated alkene [reaction (5)]. The unsaturated carbonyl X3SnCR1R2-CHR3-CR4=0 X2Sn(CR' R2-CHR3CR4=O), + ( 5 ) -30 to 120°C HX +Sn + R1R2C=CR3-CR4=0 - X = C1, Br, or I compound may be an ester, carboxylic acid, ketone, acid chloride, or an amide, and yields are generally > 90%. Some diorgano-tin dihalide is also formed, by a parallel reaction, due to the formation of tin(I1) halide, which reacts analogously *07 C. 1. Ratcliffe and T. C. Waddington, J.C.S. Faraday II, 1976, 72, 1840. 208 K. Sera, K. Suehiro, M. Hayashi, and H. Murata, Bull. Chem. SOC. Japan, 1976, 49, 29. 209 M. Cartwright and A. A. Woolf, J.C.S. Dalton, 1976, 829. 210 F. Hofler and R. Jannach, Monarsh., 1976, 107, 731. 211 V. A. Chernaplekova, N. I. Sheverdina, N. N. Zemlyanskii, and K. A. Kocheskov, J. Gen. Chem. 212 E. J. Bulten, H. F. M. Gruter, and H. F. Martens, J. Organometallic Chew., 1976, 117, 329. 213 V. F. Mironov, V. I. Shiryaev, E. M. Stepina, V. V. Yankov, and V. P. Kochergin, J. Gen. Chem. (U.S.S.R.), 1976, 45, 1497. (U.S.S.R.), 1976, 45, 2404. 136 Inorganic Chemistry of the Main-Group Elements to form X,Sn(CR1R2CHR3CR4=0), derivatives. Mechanisms involving the inter- mediate formation of H2SnX2 and HSnX, and their addition to the C=C bond were Irradiation of {(Me,Si),CH),SnCl in the presence of an electron-rich olefin produces the metal-centred R,Sn- radical. The symmetrical radical is also obtained when the unsymmetrical halide {(Me,Si),CH),MeSnI is treated in the same way, most probably due to photodisproportionation to the most stable Dicyclopentadienyltin dihalides (C,H,),SnX, (X = Cl, Br, or I) exhibit low Mossbauer quadrupole splittings, reflecting the similarity of the halide and cyclopentadienyl ligands, and predicting strong Lewis-acid character for these compounds. However, expected Lewis-base adduets are formed only when the donor is a bidentate ligand, such as 2,2'-bipyridyl or 1,10- phenanthroline, when 1 : 1 adducts (C,H,),SnX,,L, are obtained. These have a cis-chlorine-trans-cyclopentadienyl group geometry at tin. When X = C1, the complex (C5H5),SnC12,2py is formed with pyridine, but only when petroleum ether is used as the solvent. In benzene, redistribution accompanies complexation, and SnC14,2py and (CSH,),SnCl are produced. Similar behaviour is observed in all solvents when X=Br or I, and when DMSO is the donor. With terpyridyl the ionic complexes [(C,H,),SnX(ter)]'[(C,H,),SnX,]- (X = C1or Br) are obtained. The reaction of (C,H,),SnCl, with the sodium salt of dibenzoylmethane yields (C,H,),Sn(dbm),, which has cis-cyclopentadienyl groups. The treatment of C,H,SnCl with bases results in the formation only of the corresponding tin(I1) chloride complexes.216 The U.V. photolysis of a GeF4-F,-0, mixture in a quartz vessel at -78 "C yields dioxygenyl pentafluorogermanate(rv), 0,' GeK, which was characterized by its vibrational and e.s.r. spectra. The vibrational spectra indicate a polymeric, cis- fluorine-bridged structure for the anions. The white crystalline solid is unstable at 25 O C 2 1 7 The crystal structure of 2[BrF,]' [GeFJ is consistent with the ionic formulation, but there are strong interactions between ions through fluorine- bridging, giving infinite chains parallel to the a -axis. The octahedral co-ordination of the germanium is considerably distorted, and the bromine atoms have a distorted square-planar co-ordination (Figure 1 l)."' The crystal structures of three hexahalogenostannate(w) anions have been determined. The SnFz- anion in K,SnF,,H,O has a slightly distorted octahedral geometry, whilst there are two types of geometry around potassium, the one with eight-fold and the other with twelve-fold co-ordination.21' Crystals of K,SnCl, and (NH,),SnCl, are both cubic, with the K,PtCI, structure. The potassium salt undergoes a transition at 262 K to a form that is of lower symmetry (possibly tetragona1).220 The standard enthalpy of formation of the [SnClJ2- anion, AS(SnCe-)(g), has been calculated to be -1255.9 kJ mol-I. From the data, a value for the affinity of gaseous SnC1, for chloride ion was obtained (-278.4 kJ mol-1).221 Several other adducts of tin(w) halides have been studied. Adduct formation was observed between J. W. Burley, R. E. Hutton, and V. Oakes, J.C.S. Chem. Comm., 1976, 803. M. J. Gynane and M. F. Lappert, J. Organometallic Chem., 1976, 114, C4. K. 0. Christe, R. D. Wilson, and I. B. Goldberg, Inorg. Chem., 1976, 15, 1271. 214 21s 216 D. L. Tomaja and J. J. Zuckerman, Synth. React. Inorg. Metal-Org. Chem., 1976, 6, 323. '18 A. J. Edwards and K. 0. Christe, J.C.S. Dalton, 1976, 175. '19 I. A. Baidina, V. V. Bakakin, S. V. Borisov, and N. V. Podberezskaya, J. Shuct. Chem., 1976, 17, 210 J. A. Lerbscher and J. Trotter, Acta Cryst., 1976, B32, 2671. "' H. D. B. Jenkins and B. T..Smith, J.C.S. Faraday I, 1976, 72, 353. 434. Elements of Group IV 137 ’ I \ 1 Figore 11 The endless chain arrangement of 2[BrF2]+ [GeFJ, shown in projection down (Reproduced from J.C.S. Dalton, 1976, 175) [loo1 (C,H,)Re(CO),L (L=CO or PR3) and SnCl, and SnBr,, and also between (arene)M(CO), (M=Cr, Mo, or W) complexes and SnC1,.222 Me,NF and Me,NSNC react in liquid sulphur dioxide with SnCl,, yielding the adducts [Me,N][SnCl,F], [NMe,][SnCl,(NCS)], and [Me,N][SnCl,(NCS),] complexes. The [SnCl,F]- anion was thought to be probably tetrameric (with fluorine bridging), the [SnCl,(NCS)] anion dimeric (with bridging NCS groups), and the [SnCl,(NCS),] anion monomeric (with N-bonded NCS groups in trans positions about octahedrally co-ordinated tin).223 The treatment of S4N4 with S02C12 yields polymeric (SNCI),, which with additional S,N, affords S,N,Cl. This latter compound reacts with SnCl, and POCl, to give the cyclopentathiazenium salt [S,N,][SnCl,(OPCl,)]. Crystallographic studies confirm that there is octahedral co-ordination of the tin atom (Figure 12).224 The crystal structure of cis-diaqua- tetrabromotin(rv)-l,4-dioxan(k), i.e. SnBr,,2H20,~(C4H,02), has been determined Figure 12 The structure of the anion in [S,N,]+ [SnCl,(OPCl,)]- (Reproduced from J.C.S. Dalton, 1976, 928) *” B. V. Lokshin, E. B. Rusach, N. E. Kolobova,Yu. V. Makarov, N. A. Ustynyuk, V. I. Zdanovich, A. 223 K. Dehnicke, B. Busch, and J. Pebler, Z. anorg. Chern., 1976, 420, 219. 224 A. J. Banister, J. A. Durrant, I. Rayment, and H. M. M. Shearer, J.C.S. Dalton, 1976, 928. Z. Zhakaeva, and V. N. Setkina, J. Organometallic Chern., 1976, 108, 353. 138 Inorganic Chemistry of the Main-Group Elements Figure 13 Bond lengths and angles in two crystallographically independent [MeSnClJ (Reproduced by permission from Inorg. Chirn. Acfu, 1976, 20, 231) (the corresponding chloro-complex is amorphous). Octahedral cis- SnBr4,2H,0 units are linked to four glide-related neighbours by sequences -Sn- O(H)H - + - OC,H,O - - - H(H)O-Sn-. Each water molecule participates in forming two hydrogen bonds .225 Two crystallographically independent [MeSnCl,]- anions are found in [PkAs][MeSnCl,]; each has two-fold symmetry. The bond parameters for both are not unexpectedly similar, except for the ClCq- Sn-Cl,, angles, which are 104.9(7) and 126.0(6)’ (Figure 13).226 The [Me,SnC1,I2- anion possesses the trans -octahedral geometry in the pyridinium salt. There are fairly short N - - Cl distances, indicating that there is NH - - 6 C1 hydr~gen-bonding.’~~ Thermodynamic data have been reported for the reactions of tin chlorides and isothiocyanates R,SnX (X=Cl or NCS; R=Me, Et, Pr, Bu, or Ph) with various bases in benzene solution. Triorgano-tin chlorides form 1 : 1 five-co-ordinate adducts of low stability with pyridine or 4-methylpyridine. The slightly higher stability of the corresponding adducts with triorgano-tin isothiocyanates is due to entropy effects. The adducts of the isothiocyanates with 1,lO-phenanthroline are only a little more stable, showing the reluctance of the tin atom to achieve a co-ordination number of 5. NMV’N’-Tetramethyl- 1,2-diarninoethane affords either 1 : 1 adducts or five-co-ordinate 1 : 2 adducts, depending on the group R and the concentration of R,SnNCS. Other bases, e. g. tertiary amines or phos- phines, also react with R,SnNCS, but in most cases the reactions are complex, and probably involve disproportionation and the formation of tetraorgano-tin com- pounds.228 Zuckerman and his co-workers have carried out an in-depth study (Mossbauer, i.r.? and n.m.r., spectra and equilibrium and thermodynamic studies) of complexation between Me2SnC12 and substituted 1,lO-phenanthrolines and 2,2‘-bipyridyls. In each case, the Mossbauer data showed that a six-co-ordinate 1:l adduct with trans methyl groups was formed. Formation constants and thermodynamic values were determined in the temperature range 25 G T/”C S 65 in acetonitrile by the U.V. method. A second isosbestic point was observed at very high organo-tin chloride : ligand ratios, and was rationalized in terms of the 22s J . C. Barnes and T. J . R. Weakley, J.C.S. Dalton, 1976, 1786. 226 M. Webster, K. R. Mudd, and D. J. Taylor, Inorg. Chirn. Acta, 1976, 20, 231. 227 L. E. Smart and M. Webster, J.C.S. Dalton, 1976, 1924. 228 D. P. Graddon and B. A. Rand, J. OrganornetalZic Chern., 1976, 105, 51. anions Elements of Group IV 139 (7) formation of a ligand-complexed dimethyltin dication species. The formation constants fall roughly in the same order as the pK, values for the monoprotonated organic ligands as their Fe" or Co" complexes in aqueous media: 5-Mephen>5- Phphen>5-Clphen > 5-Brphen > 5-NO2phen > 4,4'-Me,bipy > bipy. All the en- tropy changes were negative, the most negative being associated with the most exothermic process; for example, the formation of the 5-Mephen adduct is the most exothermic, and is productive of the most order in the system. The formation of the 5-NO2phen complex is the least exothermic. N.m.r. '.T(Sn-C- H) values for the phenanthroline adducts fall roughly in the same order as the enthalpie~.'~~ The 'H n.m.r. spectrum of the 2,2'-bipyridyl adduct of Bu"SnC1, indicates non-equivalence for the two pyridyl rings. Similar spectra were obtained for the 1,lO-phenanthroline adduct. It was concluded that the adducts have a geometry in which the n-butyl group lies in the N-Sn-N plane of the hexaco- ordinate complex (7). Configurational rearrangement of these adducts is markedly accelerated in the presence of excess B U ~S ~C ~~. ~~' The crystal structure of a tri- organo-tin halide which is stabilized by internal co-ordination has been reported. The tin atoms in C,N-{2-[(dimethylamino)methyl~henyl}diphenyltin bromide pos- sess a distorted trigonal-bipyramidal geometry (Figure 14). The Me,NCH,C,H, Figure 14 Molecular geometry of C,N-{2-[(dimethylamino)methyl]phenyl}diphenylfin (Reproduced by permission from J, Organometullic Chem., 1976, 118, 183) 229 W. D. Honnick, M. C. Hughes, C. D. Schaeffer, and J. J. Zuckerman, Inorg. Chem., 1976,15,1391. 230 G. E. M. Ashi and T. Tanaka, J. Organometallic Chem., 1976, 120, 347. bromide 140 Inorganic Chemistry of the Main -Group Elements group spans one equatorial and one axial site, with the bromine in the other axial site. The acute endocyclic C-Sn-N bond angle in the five-membered ring, which is puckered at C(sp'), N, and Sn, is 75.3°.231 The analogous chiral methylphenyltin bromide (8) exhibits high optical stability, since the intramolecular co-ordination ,-Me (8) blocks the pathways for stereoisomerization. Dynamic processes which do occur have been investigated by the n.m.r. technique. The benzylic protons are aniso- chronous up to 123°C; therefore, up to this temperature, the rate at which the absolute configuration at the chiral tin atom inverts (SnenZ) is slow on the n.m.r. time-scale. The observation, below 30"C, of two singlets for the N-methyl protons, which coalesce at temperatures above 30°C to one singlet, has been interpreted in terms of rate-determining intramolecular Sn-N co-ordination. Consequential inversion at nitrogen (rate constant k) takes place in the con- former that contains tetraco-ordinate tin. In the pentaco-ordinated conformer, Sn--N co-ordination (rate constant k,) makes a stable prochiral assembly of the NMe, group and renders it diasterotopic. Of the two possible mechanisms by which the NMe groups can become homotopic: (i) by inversion of configuration at tin in the pentaco-ordinated conformer (k:), i.e. without prior Sn-N bond dissociation, and (ii) by Sn-N bond dissociation (kd) followed by inversion at nitrogen with concomitant rotation through 180" about the CH,-N bond and re-formation of the Sn-N bond, the latter mechanism is preferred, since it accounts for the observed dynamic n.m.r. pattern, whilst the observation that the NCH, and NMe proton resonance patterns coalesce at different rates excludes the former. The processes are summarized in Scheme 3. External ligands such as N N I ( m a (m Scheme 3 231 G. van Koten, J. G. Noltes, and A. L. Spek, J. Organometallic Chern., 1976, 118, 183. Elements of Group IV 141 PPh3, NPh3, DABCO, and pyridine do not have any effect on the dynamics, but in (Me,NCH,C6H,),MeSnBr there are two internal co-ordination sites close enough to inhibit intramolecular exchange. At -50 "C, two sets of diastereotopic NCH, protons and two sets of NMe protons (one for diastereotopic and one for homotopic protons) are observed, compatible with a pentaco-ordinated structure at low temperatures, there being one CN-bonded and one C-bonded 2- Me,NCH,C,H, group. On warming to -2O"C, coalescence occurs as the groups become equivalent on the n.m.r. time-scale by an intramolecular exchange process (pentaco-ord Sn pentaco-ord Sn'), which presumably involves a six-co- ordinate transition state or inte~rnediate.,~, Suiphu, Selenium, and Tellurium Derivatives.-Sulphides, SeZenides, and Tell- urides. A novel orange-red thiosilicate, Ag10Si3S11, is formed, in addition to Ag,SiS6, in the high-temperature reaction between silver sulphide, silicon, and sulphur. Its formulation was shown by X-ray diffraction to be silver orthosilicate thiosilicate, Aglo(SiS,) (Si2S7). The [Si2S7],- anion was previously uncharac- ter i ~ed. ~~~ Both Fe,SiS, and Fe,GeS, possess the olivine structure, in which the anions are approximately hexagonally close packed, with 5 of the tetrahedral sites occupied by silicon or germanium The crystal structure of the low- temperature form of GeS, has been redetermined, confirming (in principle) the framework described in the original GeSe, is isotypic with the high- temperature form of GeS, and has a deformed CdI, structure. Each germanium atom has distorted tetrahedral ~o-ordi nati on,~~~ Knudsen effusion studies of the sublimation of polycrystalline GeSe, at 610-750 K (by mass spectrometry) and at 614-801 K (by microbalance) at pressures of lop7 to lop4 atm demonstrate that GeSe, vapourizes congruently under these experimental conditions, accord- ing to reaction (6) as the predominant reaction, with minor amounts of vapouriza- tion to give GeSe, A germanium sulphide halide, Ge,S,Br,, has been synthesized by treating GeBr, in carbon disulphide in the presence of aluminium bromide with hydrogen sulphide. An X-ray diffraction study shows it to possess the adamantane structure (Figure 15).238 Tetrameric thiogermanates have been obtained by the reaction of alkali-metal sulphides with GeS, in aqueous solution. Cs4Ge,S,,,3HzO prepared in this way possesses the adamantane stucture in both the crystal (X-ray) and in Vibrational spectra for [Ge4SloY- anions with the adamantyl structure have been measured, and force constants and potential-energy distributions calculated.240 Crystals of Tl,Ge,S,, consist of nearly tetrahedral [Ge4Slo14- anions held together by Tl' anions. The anions are com- posed of four GeS, tetrahedra which share vertices.241 Pure selenogermanates GeSe, (s) GeSe (g) + $Se, (8) (6) 232 G. van Koten and J . G. Noltes, J. Amer. Chem. SOC., 1976, 98, 5393. 233 J. Mandt and B. Krebs, Z. anorg. Chem., 1976, 420, 31. 234 H. Vincent, E. F. Bertaut, W. H. Baur, and R. D. Shannon, Acta Cryst., 1976, B32, 1749. 235 G. Dittmar and H. Schafer, Acta Cryst., 1976, B32, 1188. 236 G. Dittmar and H. Schafer, Acta Cryst., 1976, B32, 2226. 237 E. A. Irene and H. Wiedemeier, 2. anorg. Chem., 1976, 424, 277. 238 S. Pohl, Angew. Chem. Internat. Edn., 1976, 15, 162. 239 S. Pohl and B. Krebs, 2. anorg. Chern., 1976, 424, 265. A. Miiller, B. N. Cyvin, S. J . Cyvin, S. Pohl, and B. Krebs, Spectrochim, Acta, 1976, 32A, 67. G. Eulenberger, Acta Cr yst ., 1976, B32, 3059. 241 142 Inorganic Chemistry of the Main- Group Elements 0 Ge 0 s @ Br f /I 2.273 Figure 15 Molecular structure of Ge4S6Br4 (Reproduced by permission fromAngew. Chem. Internat. Edn., 1976, 15, 162) have been prepared by treating GeSe, with Na,Se in an aqueous medium. Crystals of Na,GeSe,, 14H,O obtained at high pH contain tetrahedral [GeSe4f4- anions, connected to hydrated cations by extensive hydr~gen-bonding.’~’ y- AhGeTe, is cubic, with a structure consisting of a rigid body of tellurium atoms consolidated by GeTe, tetrahedra.243 Tin-1 19m Mossbauer spectra have been reported for ternary sulphides obtained from the Na2S-SnS2, Bas-SnS,, and PbS-SnS, systems. From the data, it was established that the isomer shifts are sensitive to the co-ordination number at tin, and, for the high-temperature forms of Na,SnS, and BaSnS,, distorted tetrahedral geometries at tin were The phase Cu,SrSnS,, prepared from a mixture of the three binary sulphides at 620-700 “C, has tetrahedrally co-ordinated tin and copper atoms. The co- ordination at strontium is that of a deformed Archimedean anti pri ~m.,~~ Pb0.46M03S4 and Pbo,,oMo3Se4 are isostructural, with the lead atoms co-ordinated by eight sulphur or selenium atoms in a distorted cubic envi r~nment.’ ~~ Gladite, PbCuBi,S,, is orthorhombic, and is a superstructure intermediate in the series Bi2S3 (bismuthinite)-PbCuB& (aikinite). The structure can be described as a derivative of bismuthinite, in which of the bismuth atoms are replaced by lead atoms and copper atoms are added to f of the available tetrahedral interstices, in locations associated with the lead atoms.247 Molecular Sulphur and Selenium Compounds. Organo- tin mercapto-esters and ester chlorides of the general formula Bu,Sn[S(CHJ1 or,C02R],C14-~,+,~( n = 1, rn = 1-3; n = 2, rn = 1 or 2) have been synthesized by standard methods. The butyltin mercapto-ester chlorides exist not as ‘pure compounds but as mixtures in equilibrium with their respective butyltin mercapto-esters and butyltin chlorides. The results suggest that the anhydrous reactions between butyltin chlorides and iso-octyl thioglycolate give almost entirely butyltin (iso-octyl thioglycolate) chlorides, in contrast to the previous reports which stated that these reagents gave 242 B. Krebs and H. J. Jacobson, 2. anorg. Chern., 1976, 421, 97. N. Rysanck, P. Larvelle, and A. Katty, Acta Cryst ., 1976, B32, 692. R. Greatrex, N. N. Greenwood, and M. Ribes, J.C.S. Dalton, 1976, 500. J. Guillevic, H. Lestrat, and D. Grandjean, Acta Cryst., 1976, B32, 1342. 243 244 245 C. L. Teske, Z. anorg. Chem., 1976, 419, 67. 247 I. Kohatsu and B. J. Wuensch, Acta Cryst., 1976, B32, 2401. 246 Elements of Group IV 143 the trans -isomer of butyltin (iso-octyl thi ogl y~ol ate).~~~ The reaction of GeCl, with carbon disulphide in the presence of a secondary amine gives the ionic complex (R,NH,),Ge[SC(S)NR2],.249 Mixed dimethyltin carbamate complexes of the type Me,SnLL' [LL' = all combinations of SC(O)NMe,, SeC(O)NMe,, S2CNMe2, SSeCNMe,, and Se,CNMe, except for S,CNMe, with Se,CNMe,] have been prepared by metathesis, using the dimethylammonium salt. N.m.r. spectra indicate that all the ligands function as bidentate donors towards tin, and that the mixed carbamate complexes disproportionate to the corresponding bis- carbamates and exist as equilibrium mixtures with statistical ratios (-1 : 2 : 1) in solution. The XYCNMe, ligands ( X Y = SS, SSe, or SeSe) co-ordinated to tin are more labile than the YC(O)NMe, (Y = S or Se) l i gand~. ~~~ Line-shape analysis of the variable-temperature 'H n.m.r. spectra of the compounds X,Sn(S,CNPf,), [X = C1(l ), Me (2)] and X,Sn(Se,CNPi,), [X 7 Cl(3) and Me (4)] in chloroform have been investigated in an attempt to obtain the activation parameters of internal rotation around the Pi-N bond. The calculated barriers to internal rotation r18.3 (l), 16.4 (2), 16.5 (3), and 13.9 kcal mol-' (4)] were discussed in terms of steric repulsion between the Pf groups and the sulphur or selenium atoms.251 Both of the dithiocarbamate groups chelate the tin atonis in PhClSn(S,CNEt,),, rendering the metal six-co-ordinate. The chlorine atom and the phenyl group occupy mutually cis positions (Figure 16).252 The silyl and c 4 c 10 " c 14 Figure 16 Structure of PhCISn(S,CNEt,), (Reproduced by permission from J. Orgunometullic Chem., 1976, 120, 211) 248 R. E. Hutton and J. W. Burley, J. Organometallic Chem., 1976, 105, 61. I. Tossidis, A. Singollitou-Kourakou, and G. Manoussakis, Inorg. Nuclear Chem. Letters, 1976, 12, 357. 249 250 K. Tanaka, S. Araki, and T. Tanaka, Inorg. a i m . Acta, 1976, 16, 107. 251 Y. I. Takeda, N. Watanabe, and T. Tanaka, Spectrochim. Acta, 1976, 32A, 1553. P. G. Harrison and A. Mangia, J. Organometallic Chem., 1976, 120, 211. 252 144 Inorganic Chemistry of the Main -Group Elements germyl arylselenides H,MSePh (M = Si or Ge), H,Si(SePh),, and MMe,H,-,(SePh) (M = Si, n = 2 or 3; M= Ge, n = 1-3) have been prepared by the reaction of the metal halide and LiSePh, LiAl(SePh),, or Me,SiSePh. The germyl derivative could be obtained from the reaction of H,GeNCNGeH, with PhSeH. Me,SnSePh was prepared by metathesis from the chloride. The reactions of Me,SiSePh and Me,SiSeMe with chloro-boranes and chloro-phosphines yield analogous selenium-boranes and -ph~sphi nes.~~, Nitrogen and Phosphorus Derivatives.-The molecular structure, microstructure, macrostructure, and properties of silicon nitride have been reviewed.254 The preparation of pure a- and @-phases of germanium nitride requires rigorous control of the composition of the nitriding gas and temperature. For a given NH3-H2 mixture, the @-phase is obtained at a higher temperature than the a-phase. The P-phase may be prepared in a pure form by the reaction of ammonia with elemental The ternary germanium phosphide Ag6Ge10P12 has been synthesized from the elements by heating at 1000°C. The material is diamagnetic and a semiconductor. Crystals are cubic, with octahedral Ge, clusters which are connected to [AgsGe,P,,] groups which have the same structure as Rb(CO),,. Six germanium atoms are tetrahedrally co-ordinated by phosphorus, whilst the remaining four have trigonal-bipyramidal co-ordi nati ~n.~~~ Yellow, hydrolytically sensitive diarylketimine derivatives of silicon, ger- manium, and tin have been prepared by the reaction of the metal halides and the lithium salt of the keti mi ~~e. ~~~ Trimethyltin derivatives of aziridines may be obtained similarly, or by protolysis of Me,SnNMe, by the parent aziridine. Trimethyltin(aziridine), Me,SnN(CH,),, is associated in the solid (9), but is dimeric in solution (10). A 1 : 1 adduct is formed with BF,. Derivatives of other substituted aziridines are monomeric.25g The crystal structure of dimethoxyporphinatogermanium(rv) has been reported. The co-ordination around germanium is slightly distorted Ger- manium and silicon carbodi-imides (Me,H,-,MN:),C (M= Si or Ge; n = 1, 2, or 3) have been prepared by metathesis of the metal halides with Pb”, Ag’, or Siw species. The Ge-N bond is readily cleaved by protic reagents, and therefore these are useful as synthetic intermediates for the formation of the chalcogenide derivatives [(Me,H,-,)Ge],E (E=O, S, Se, or Te) and R,GeSR. The silicon 253 J. E. Drake and R. T. Hemmings, J.C.S. Dalton, 1973, 1730. 254 H. M. Jennings, J. 0. Edwards, and M. H. Richman, Inorg. Chim. Acta, 1976, 20, 167. 2s 5 J. C. Remy and Y. Pauleau, Inorg. Chem., 1976, 15, 2309. ”’ J. KeabIe, D. G. Othen, and K. Wade, J.C.S. DaZton, 1976, 1. 25E M. E. Bishop and J. J. Zuckerman, Inorg. Chim. Acta, 1976, 19, L1. 2s9 A. Maundis and A. Tulinsky, Inorg. Chem., 1976, 15, 2723. H. G. von Schnering and K. G. Hauler, Rev. Chim. minerale, 1976, 13, 71. 256 Elements of Group IV 145 compound is not susceptible to pro tolysis by heavier chalcogeno1s.260 Electron- diffraction studies of H,GeNCO and H,GeN=C=NGeH, indicate non-linear heavy atom skeletons which are bent at nitrogen for both.261 The complex tin- (L = pyridine, 3-cyanopyridine, nicotinamide, ethyl nicotinamide, or ethylene- diamine) have been prepared. Spectroscopic data suggest an NCS-bridged struc- ture for NiSn(NCS)6, and a cationic-anionic structure for the other two.262 Mixed methyltin chloride phosphines of the types Me,ClSnPBu;, MeCl,SnPBu;, MeCISn(PBut),, and Me,ClPBu\ have been synthesized by ex- change between the methyltin chloride and Me,SiPBu\. Exchange with Me,SnCl produces Me,SnPBui, whilst exchange of Me,Sn(NEt,), with Me,SiX (X = C1or Br) gives the silylamine and M~,XSI I NE~,.~~~ The mixed dimethyltin chloride phosphine and its germanium analogue, Me,ClEPBu; (E = Ge or Sn), react with the Group VI metal carbonyl-THF complexes M(CO),(THF) (M = Cr, Mo, or W) to yield the complexes M(CO),{PBU\EM~,C~}.~~~ The similar organo-tin phos- phine complexes W(CO),{PPh,(SnMe,)} and W(CO)4{P(OMe),}{S(SnMe3)2} have also been obtained by irradiation of the metal carbonyl in the presence of the ligand.265 The stannaphospholans (1 1) exhibit diastereotopic methyl groups in their n.m.r. spectra. The activation energy for inversion at phosphorus was determined from the coalescence temperature.266 isothiocyanate COmpkXeS NiSn(NCS),, [NiL4][Sn(NCS),], and [NiL,][Sn(NCS)6] Me 2 S l , l Ph (1 1) Derivatives with Bonds to Main-Group Metals.-Tri-t-butylsilane protolyses the Cd-C bonds of diethylcadmium, forming ( Bu\ S~) , C~. ~~~ X-Ray diffraction studies of (Me,Si),Hg show that the compound has a linear SiHgSi framework, consistent with the vibrational spectra.268 The reactions of the two stannyl- mercurials (R,Sn),Hg (R = Me,SiCH, or neopentyl) have been investigated. Photolysis of the neopentyl derivative affords quantitative yields of the corres- ponding hexa-alkylditin and metallic mercury, whilst reaction with elemental sulphur or 1,2-dibromocyclohexane gives triorgano-tin sulphide and bromide, respectively. The reaction with perfluoroalkyl-mercurials generally gives the triorgano-tin fluoride and perfluoro-olefin. Photolysis of a mixture with (Et,Ge),Hg yields the two symmetrical compounds (neopentyl),Sn, and EkGe,, with only 18% of the unsymmetrical product (ne~pentyl),SnGeEt,.~~~ Treatment 260 J . E. Drake, R. T. Hemmings, and E. Henderson, J.C.S. Dalton, 1976, 366. 262 P. P. Singh and S. B. Sharma, Canad. J. Chem., 1976, 54, 1563. 263 H. Schumann, W. W. Du Mont, and H. J . Kroth, Chem. Ber., 1976, 109, 237. 265 H. C. E. McFarlane, W. McFarlane, and D. S. Rycroft, J.C.S. Dalton, 1976, 1616. 266 C. Comet, J. EscudiC, J. Satge, and G. Redoules, Angew. Chem. Internat. Edn., 1976, 15, 429. 267 L. Rijsch and H. Miiller, Angew. Chem. Internat. Edn., 1976, 15, 620. 268 P. Bleckmann, M. Soliman, K. Reuter, and W. P. Neuman, J. Organometallic Chem., 1976,108, C18. 269 0. A. Kruglaya, B. V. Fedot’ev, I. B. Fedot’eva, and N. S. Vyazankin, J. Gen. Chem. (U.S.S.R.), J . D. Murdoch, D. W. H. Rankin, and B. Beagley, J. Mol. Structure, 1976, 31, 291. H. Schumann, J. Held, H. J. Kroth, and W. W. Du Mont, Chem. Ber., 1976, 109, 246. 1976, 46, 1483. 146 Inorganic Chemistry of the Main -Group Elements of the trimethylsilylmethylstannyl-mercurial with transition-metal cyclopenta- dienyl carbonyl compounds [M(CO),(C,H,)], in THF results in the formation of triorgano-tin-M(CO),(C,H,) (M = Ni, n = 1 ; M = Fe, n = 2; M = Mo, n = 3) de- rivatives. Photolysis of R,SnMo(CO),(C,H,) (R = Me,SiCH2) promotes symmetri: zation to (Me3SiCH2)6Sn2 and [MO(CO),(C,H,)],.~~~ Trimethylchlorosilane reacts with aluminium and lithium metals in the presence of mercury in DME-THF to form Li[A1(SiMe,),],2DME.27 Electron-diff raction studies of gaseous cyclopentasilane show that its structure is very similar to that of cyclopentane. The ring is puckered, but it cannot be established whether the molecule undergoes dynamic pseudorotation or exists in a single static c~nfi gurati on.~~~ Dodecamethylcyclohexagermane, Ge6Me12, is iso- structural with the previously reported silicon analogue.273 The structure of Si,Me,, has been determined by X-ray diffraction. Each molecule contains a bicyclo[3,3,l]-system, with a six-membered polysilane ring in the chair confor- mation and a six-membered polysilane ring in which five of the atoms are roughly coplanar (Figure 17).274 The relative rates and extent of Si-Si bond cleavage by Figure 17 Structure of Si,Me,, (Reproduced by permission from Inorg. Chem., 1976, 15, 524) lithium of cyclo-Si,Ph, and cyclo-Si,(p-tolyl), have been determined. The reaction of the resultant product cyo-dilithio peraryl-polysilanes with K2PtC14 yields peraryl-cyclopentasilanes.275 Permethyldisilacyclobutene reacts with acetylenes to afford disilacyclohexadienes, most probably by a Diels-Alder addition of the acetylene to the ring-opened silane 1,4-disila-buta-1,3-diene as the inter- mediate276 (Scheme 4). Disilane and digermane compounds may be obtained by the metal-promoted coupling of dialkylmetal chloride hydrides [reaction (7)]. Sodium-potassium alloy is used to remove the halogen when X = Si, but mag- nesium is preferred when X = Ge. High yields of Me2C1GeGeC1Me, are obtained 270 B. I. Petrov, G. S. Kalinina, and Yu. A. Sorokin, J. Gen. Chem. (U.S.S.R.), 1976, 45, 1873. 271 L. Rosch, J. Organometallic Chem., 1976, 121, C15. 272 Z. Smith, H. M. !kip, E. Hengge, and G. Bauer, Acta Chem. Scad. (A). 1976, 30, 697. 273 W. Jensen and R. Jacobson, Cryst. Struct. Comm., 1975, 4, 299. 274 W. Stallings and J. Donohue, Inorg. Chem., 1976, 15, 524. 275 M. F. Lemanski and E. P. Schram, fnorg. Chem., 1976,15, 2515. 276 T. J. Barton and J. A. Kilgour, J. Amer. Chem. SOC., 1976, 98, 7746. Elements of Group IV M Me LSiMe, Scheme 4 141 71R when hexamethyldigermane is treated with concentrated sulphuric acid and ammonium chloride.277 An X-ray diffraction study of the 2,2’-bipyridyl adduct of 1,1,2,2-tetrachloro-1,2-dimethyldisilane, viz. Cl,MeSiSiMeCl,,bipy, shows that R,EHCl + R,HEEHR, Brz Or IZ ’ R,XEEXR, (7) E =Si or Ge; R =Me or But the bipyridyl chelates one silicon atom, raising its co-ordination number to six, rather than bridging the two silicon atoms (Figure 18).278 Figure 18 Structure of MeCl,SiMeCl,,bipy (Reproduced by permission from Chern. Ber., 1976, 109, 3728) The reaction of oligomeric dimethyltin with (Me,SnS), leads to a five- membered heterocycle, 2,2,4,4,5,5-hexamethyl-1,3-dithia-2,4,5-tristannolan (12), Me2 S,Sn\S I I Me,Sn - SnMe, (12) for which a vibrational analysis of its i.r. spectrum excludes a planar configura- Crystals of 1,1,2,2-tetrakis(pentacarbonylmanganio)-l,2-dibromoditin consist of discrete units of Br,Sn,[Mn(CO),L. The two connected tin atoms are each tetrahedrally surrounded by two Mn(CO), groups and one bromine atom. Each manganese atom is octahedrally co-ordinated. The four equatorial carbonyl 277 K. Triplett and M.’ D. Curtis, J. Organometallic Chem., 1976, 1M, 23. 27R G. Sawitzki and H. G. von Schnering, Chem. Ber., 1976, 109, 3728. 279 B. Mathiasch, J. Organometallic Chem., 1976, 122, 345. 148 Inorganic Chemistry of the Main-Group Elements Figure 19 Structure of Br,Sn,[Mn(CO),], (Reproduced by permission from Inorg. Chern., 1976, 15, 339) groups in each Mn(CO), group are bent away from the axial carbonyl group by 2.7" (av.). The Sn-Sn and Sn-Br distances, 2.885(1) and 2.576(1)& respec- tively, are unusually long (Figure 19).'" Hexamethyl- and hexabutyl-ditins react with aryl and benzyl halides in the presence of Pd(PAr,), to afford trialkylaryl- stannanes. No aryl-tin compound was formed in the case of p-nitrophenyl halide, since coupling to give the Ar-Ar product is favoured by the electron-with- drawing substituent. Me,SnC6H4N02-p could be obtained, however, by the reac- tion of Me,SiSnMe, with the nitro-aromatic compound.2g1 The photochemical reaction of polymeric dibutyltin, (Bu2Sn),, with alkyl halides RX gives the triorgano-tin halides Bu,RSnX by insertion of the inter- mediate stannylene Bu2Sn: into the C-X bond of the alkyl halide. The reactions proceed quickly under mild conditions to give good yields, with Bu3SnX as the only by-product, although in very small quantities. Reactions with dihalogeno- methanes were also successful, affording halogenomethyltin compounds XBuzSnCHzX.282 The reactions of hexabutylditin with arylsulphonyl isocyan- a t e ~ ~ ~ ~ and aryl, benzoyl, and phenylsulphonyl azides2*, have been examined. With the arylsulphonyl isocyanates RC,H,SO,NCO (R = H, Me, or MeO), NN'- bis(arylsulphony1)-N-(tributylstanny1)ureas were obtained as the major products, A. L. Spek, K. D. Bos, E. J. Bulten, and J. G. Noltes, Inorg. Chem., 1976, 15, 339. 281 D. Azarian, S. S. Dua, C. Eaborn, and D. R. M. Walton, J. Orgunometallic Chem., 1976,117, C55. 2R2 S. Kozima, K. Kobayashi, and M. Kawanisi, Bull. Chem. SOC. Japan, 1976, 49, 2873. 283 N. I. Mysin and Yu. I. Dergunov, J. Gen. Chem. (U.S.S.R.), 1976, 46, 151. 284 Yu. 1. Dergunov and N. I. Mysin, J. Gen. Chem. (U.S.S.R.), 1976, 46, 2648. Elements of Group IV 149 along with carbon monoxide, tetrabutyltin, and tributyltin isocyanate. rn - ClC6H4NC0 is less reactive, and rn-C1C6H4N(SnBu,)COSnBu, is formed.283 Evolution of nitrogen accompanies the reaction with azides, and the stannyl- amines RN(SnBu,), (R=Ph, COPh, or S0,Ph) are produced, probably via the initial addition product RN(SnBu,)*N=N*SnBu,. The sulphonylamino-tin com- pound thus obtained reacts with rn-C1C,H4NC0 to afford the 1:l adduct PhS02N(SnBu,)C0,N(SnBu3)(C,H,C1-m), and undergoes stepwise Sn-N bond cleavage by protic reagents.284 Tin-lead-bonded compounds such as Me,SnPbMe, and Ph,SnPbMe, have been synthesized by the protolysis of Me,PbNEt, with the triorgano-tin hydride. The stannylaminoborane Me,SnB(NMeCH,), has been obtained by the treatment of Me,SnLi with ClB(BMeCH2)2.28s The preparation, stability, and storage of pure samples of hexamethyldilead have been discussed. The best method of synthesis is by the reaction of lead(r1) chloride with methyl- magnesium iodide. The thermal decomposition in hydrocarbon or carbon tetra- chloride solutions was suggested to involve Me,Pb formation, followed by a radical chain when carbon tetrachloride is solvent. Both catalysed and uncatalysed methanolysis was found to proceed by initial protic cleavage of the Pb-C bond.286 Hexamethyldilead reacts with various metal salts very rapidly (in com- parison with the rates of mixing of the reactants), so that the product composition depends upon the order of addition and the competition between rapid reactions rather than upon any fundamental differences in the Diffraction studies of hexaphenyldilead show it to possess the staggered conformation (Figure PH2 d H 13 Figure 20 Structure of Pb,Ph, (Reproduced by permission from 2. anorg. Chem., 1976, 419, 92) ’” 5. D. Kennedy, W. McFarlane, and B. Wrackmeyer, Inorg. Chem., 1976,15, 1299. 286 D. P. Arnold and P. R. Wells, J. Organometallic Chern., 1976, 111, 269. ’*’ D. P. Arnold and P. R. Wells, J. Organometallic Chern., 1976, 113, 311. ’” H. Preat and F. Huber, Z. anorg. Chem., 1976, 419, 92. 150 Inorganic Chemistry of the Main-Group Elements Derivatives with Bonds to Transition Metals.-The reaction of silyl iodide with the sodium or thallium salt of the [v(co)6]- anion yields H3SiV(C0)6 as a volatile orange solid. The i.r. spectrum is consistent with C3, symmetry.289 The structures of H,SiRe(C0),,2’* H,GeRe(C0),,2’’ and H,G~CO(CO)~’ ~ have been deter- mined by electron diffraction, In each, the equatorial carbonyl groups are bent towards the MH3 group. The anions in the salt [NEt,]+ [Fe(CO),SiCl,]- possess C,, symmetry, with the carbonyl groups and chlorine atoms in a staggered conformation. Again, the equatorial carbonyl groups are bent towards the Group N metal. The Si-Fe bond shows an appreciable shortening with respect to the theoretical covalent bond distances, indicating that there is some degree of multiple b~ndi ng.~” Ph,SiCo(CO), reacts with methyl-lithium or with methyl-, ethyl-, or allyl-magnesium bromide (RM) in ten-fold excess to form ‘LiSiPh3’ or ‘Ph,SiMgBr’. Reactions of the chiral silyl-cobalt compound (+)-(CO),CoSiMe- PhNp (Np = naphthyl) with organometallic reagents, followed by hydrolysis, gave the silane, with 70% retention in the case of methyl-lithium and 55% retention in the case of methylmagnesium br~mi de.”~ The germyl-cobalt compounds R,GeCo(CO), (R,Ge = H3Ge, MeH,Ge, or Me2HGe) react, in diethyl ether, with the [Mn(CO),]- anion to give R,GeMn(CO), compounds, while the [Mn(CO),]- anion displaces [Fe(C0),l2- or [(H,Ge)Fe(CO),]- from (H3Ge)2Fe(C0)4.294 NaCo(CO), reacts with SiI, to yield the complex (CO),Co,Si-Co(CO),, the structure of which is shown in Figure 21. The silicon atom is part of the tetrahedral cluster unit Co,Si, whilst a Co(CO), group is bound to the silicon atom as a fourth ligand. The compound is thus the silicon analogue of the methylidene (CO),Co,C-Y Several spectroscopic studies of tin- cobalt compounds have been published. Descriptions of two far4.r. (600- 80 cm-l) studies of alkylhalogeno-tin derivatives of tetracarbonylcobalt have The purity of the tin-cobalt stretching modes decreases in going from chlorine to iodine in complexes of the type Me,-,X,SnCo(CO), (X = C1, Br, or I). van der Kelen et al. have collated n.m.r., n.q.r., nuclear gamma resonance, dipole moment, and i.r. data for these types of tin-cobalt derivative, and have come to the following conclusions: (i) the degree of Co-Sn v-participation is non-zero, but is dominated by the a-bonding effect; (ii) the organo-tin group is the stronger a-donor, and the halogen behaves as a a-acceptor or a weak a-donor; (iii) the relative n-bond orders are difficult to assign; however, n- bonding seems to make the largest contribution in the Co-Sn bond of organo- tin-substituted cobalt carbonyls; (iv) the metal-metal bond seems to have a synergistic character, since the better u-donor acts as the better v-acceptor, and vice versa; and (v) it is still open to question as to what extent the X-Sn (I, + d)m-bonding in halogeno-tin-substituted cobalt carbonyls influences the 289 J . S. Allinson, B. J . Aylett, and H. M. Colquhoun, J. Orgunometallic Chem., 1976, 112, C7. D. W. H. Rankin and A. Robertson, J. Orgunometallic Chem., 1976, 105, 331. 291 D. W. H. Rankin and A. Robertson, J. Orgunometullic Chem., 1976, 104, 179. 292 P. R. J ansen, A. Oskam, and K. Olie, Cryst. Struct. Comm., 1975, 4, 667. 293 E. Colomer and R. Corriu, J.C.S. Ge m. Comm., 1976, 176. 294 R. F. Gerlach, B. W. L. Graham, and K. M. Mackay, J. Organometallic Chem., 1976, 118, C23. 295 G. Schmid, V. Batzel, and G. Etzrodt, J. Organometullic Chem., 1976, 112, 345. 296 L. F. Wuyts and G. P. van der Kelen, Spectrochirn. Actu, 1976, 32A, 689. 297 L. F. Wuyts and G. P. van der Kelen, Spectrochim. Actu, 1976, 32A, 1705. Elements of Group IV 151 Figure 21 Structure of (CO),Co,Si-Co(CO), (Reproduced by permission from J. Organometallic Chem., 1976, 112, 345) Co-Sn intera~tion.'~' "GI n.q.r. and low-temperature 13C n.m.r. spectra have been recorded for the complexes X,SnCo(CO), (X=PhCH,, Bu, Ph, Me, or Cl). The variable-temperature 13C n.m.r. data show axial-radial exchange of carbonyl groups with the single line observed at room temperature becoming two (in the ratio 1 : 3) at temperatures lower than -111 to -119 "C for the alkyl derivatives. The slow-exchange region was not reached even at -155 "C for X= Cl.299 The kinetics of the cleavage of the Sn-Co bond in Me,SnCo(CO), and of the Sn-Re bond in Me,SnRe(CO), by iodine have been measured. The order of the rates of cleavage of the Sn-M bonds in the compounds Me,SnM(CO), (C,H,), (M = Mn or Re, x = 5, y = 0; M = Co, x = 4, y = 0; M = Cr, Mo, or W, x = 3, y = 1 ; M = Fe, x = 2, y = 1) indicates that the main factors determining the reactivity towards iodine are the size of the atom M and the shielding of it by other ligands. Their 298 L. F. Wuyts, G. P. van der Kelen, and Z. Eeckhaut, J. Mol. Structure, 1976, 33, 101. 299 D. L. Lichtenberger, D. R. Kidd, P. A. Loeffler, and T. L. Brown, J. Amer. Chem. Soc., 1976, 98, 629. 152 Inorganic Chemistry of the Main-Group Elements kinetics show that the reactions proceed in two Rate coefficients have been determined for the reactions in CCl, of iodine with Fe(C,H,)(CO),(MMe,) (M = Si, Ge, or Sn), Mo(C,H,)(CO),(SnR,) and Fe(C,H,)(CO),(SnR,) (R = Me, Bu, or Ph), Mn(CO),(SnR,) (R = Me, Et, or C,H,,), Mn(CO),(MMe,) (M = Si, Ge, Sn, or Pb), and Mo(C,H,Me)(CO),(SnPh,). The alkyl groups attached to the Group IV metal influence the reactivity as would be expected from a considera- tion of their electronic properties rather than expected from their steric effects. The reactivity increases as silicon is replaced by germanium, tin, and lead, as a consequence of the vertical hyperconjugation and increasing stability of the MMe; The reaction of Fe,(C0)9 with vinyldisilane RMe,Si-SiMe,CH=CH, (R = Me or CH=CH2) affords the novel sila-allyl-iron tricarbonyl complex ( 13).302 Treat- ""\ /"" Si 4- F.. H-C I - Fe(CO),(SiMe,R) /"\ H H ment of the sila-iron tricarbonyl complex (14) with Ph3C' P E yields the ionic complex 1 ,l-d~methyl-2,2-dialkyl-l-silacyclohexadienyliron tricarbonyl hexa- fluorophosphate ( 15).303 The reaction of poly(si1yl)benzenes with Co,(CO),, Fe,(CO),, Ru3(CO),,, or (Ph3P),PtC2H4 results in the formation of bis(sily1) chelate complexes of Co, Fe, Ru, and Pt such as (16) and (17).,04 The photolysis ML, =M(CO), (M =Fe or Ru) or Pt(PPh,), 3w J. R. Chipperfield, A. C. Hayter, and D. E. Webster, J. Organometalk Chem., 1976, 121, 185. 301 J. R. Chipperfield, J. Ford, A. C. Hayter, and D. E. Webster, J.C.S. Dalton, 1976, 360. 302 H. Sakurai, Y. Kamiyama, and Y. Nakadaira, J. Amer. Chem. SOC., 1976, 98, 7453. 303 W. Fink, Helu. Chim. Acta, 1976, 59, 276. W. Fink, Helu. Chim. Actu, 1976, 59, 606. Elements of Group N 153 of dimethyltin bis(meta1 carbonyl) complexes proceeds by the loss of one carbonyl group and ring closure to give M-M bonds that are bridged by carbonyl and Me,Sn bridges. Upon similar treatment, dimethylchlorotin metal carbonyl deriva- tives give complexes with M-M bonds that are bridged by two Me,Sn groups. Thus, Me,Sn[Fe(CO),(C,H,)], gives (p-CO)( p-Me2Sn)Fe2(CO),(C,H,),, and Me,ClSnMn(CO), gives (p-Me,Sn),Mn,(CO),. Photolysis of Me,Sn[Co(CO),], yields (p-Co)(p-Me,Sn)Co,(CO), at 25 "C, but (p-CO)(p-Me,Sn)Co,(CO), at -50 "C. No reaction was observed with Me,Sn[Mn(CO),],.305 Contrary to previ- ous reports, ti&) halides react straightforwardly with [(C,H,)Fe(CO),], in THF to give the insertion products X,Sn[Fe(CO),(C,H,)], as long as moisture and oxygen are excluded.306 Complexes of SnCl, and GeCl, with a number of metal carbonyls, including M(C0)6 (M = Cr, Mo, or W), Fe(CO),, Fe,(CO),, Fa3(CO)12, Co,(CO),, (n-arene)M(CO), (M = Cr, Mo, or W), (C5H5)V(C0),, Mn(CO),Cl, Co(NO)(CO),, and Fe(NO),(CO), have been prepared, using both thermal and photochemical procedures.307 The photochemical reactions of the SnC1, anion with metal(o)-trifluorophosphine Complexes of Ni, Fe, and Mo yield the complex ions [Ni(PF3),SnC13]-, [Fe(PF,),(SnCl,),]-, and [MO(PF,),S~C~~]-.~~~ The mass spectra of (C,H,)Fe(CO),SnX, (X=C1 or Me) have been 13C n.m.r. spectroscopy has been used to study the stereochemistry in M(CO),(SnMe,), complexes. The iron and ruthenium complexes exist solely in the cis-form, but the osmium derivative exists as a mixture of isomers, with ca. 20% of the trans-form. The preservation of Sn-Co coupling in the high-temperature limiting spectra of the cis-complexes shows that the process of averaging of axial and equatorial carbonyl groups does not occur by dissociation. Rather, the pattern of coalescence in cis-trans mixtures strongly suggests that the averaging proceeds by a process that involves cis-to-trans-to-cis i someri zati ~n.~~~ 13C n.m.r. spectroscopy has also been employed to study the preferred orientations and rotational barriers of T -olefin complexes, e. g. (C5H5)Fe(CO)(olefin)SnR, .31 ' The complexes Mn(CO),(CNMe),_,SnR, (n = 2-4; R = Me or Ph) have been obtained by substitution of the organo-tin chloride by the corresponding [Mn(CO), (CNMe),_,]- anion.312 Several acylate salts and non-cyclic carbene com- plexes of manganese and rhenium containing organo-germanium ligands have been prepared by the reactions of the cyclic germoxycarbene complexes of empirical formula Ph,GeM(CO),COMe (M = Mn or Re) with either methyl- lithium or sodium methoxide. The products can be rationalized by the postulate that there is nucleophilic attack at germanium.313 The reaction of Mn(CO),- (SnPhC1,) with the thallium salt of pentane-173-dione (pd) yields cis-Mn(CO),- {SnPh(pd),}]. The tin atom may also be complexed with phenanthroline, giving 30s K. Triplett and M. D. Curtis, Inorg. Chem., 1976, 15, 431. 3M J . D. Cotton and A. M. Trewin, J. Organometallic Chem., 1976, 117, C7. 307 T. Kruck and W. Molls, 2. anorg. Chem., 1976, 420, 159. 308 T. Kruck, K. Ehlert, and W. Molls, 2. anorg. Chem., 1976, 422, 59. 309 G. Innorta, A. Foffani, and S. Torroni, Inorg. Chim. Acta, 1976, 19, 263. 311 J. W. Faller, B. V. Johnson, and C. D. Schaeffer, J. Amer. Chem. SOC., 1976, 98, 1395. 312 R. D. Adams, Inorg. Chem., 1976, 15, 174. 313 M. J . Webb and W. A. G. Graham, Canad. J. Chem., 1976, 54, 2557. L. Vancea, R. K. Pomeroy, and W. A. G. Graham, J. Amer. Chem. SOC., 1976, 98, 1407. 310 154 Inorganic Chemistry of the Main - Group Elements trans-Mn(CO)5{SnPhCl,(phen)}].314 Cleavage of (-)-[(C,H,)Mn(CO)(H)SiMe- PhNp] (Np = naphthyl) by electrophiles and nucleophiles may occur in three ways: electrophilic cleavage of the Si-Mn bond, with retention of configura- tion at silicon; nucleophilic attack at manganese, also with retention of configuration at silicon; and nucleophilic attack at silicon, with inversion of configuration at silicon.315 The crystal structures of (OC),(Me,Si)(PPh3)Mn3l6 and Mn2(C0)8[p- Sn(Br)Mn(C0),],317 have been determined. In the former compound the silicon and phosphorus are mutually trans, and the Si-Mn bond distance is significantly shorter than expected. The latter consists of a planar four-membered Sn2Mn, ring with a Mn-Mn bond, each tin atom being bonded to a bromine atom and a Mn(CO), group (Figure 22).3'7 Carbene complexes of formulae 02' , Figure 22 Structure of Mn2(C0),[p-Sn(Br)Mn(C0),1, (Reproduced by permission from 2. anorg. Chern., 1976, 422, 47) C13GeMn(CO),C(OR1)R2 and (C,H,)Mo(CO),(GeCl,)C(OR')Me have been pre- pared by the reaction of Et,N' GeClT with MeMn(CO),, PhMn(CO),, and (C,H,)Mo(CO),Me followed by alkylation of the resulting trichlorogermylacyl- carbonylme tallate l8 The complexes (C,H,)Mo(CO)(CNMe),(SnMe,), ( n = 1 or 2) have been pre- pared by the substitution The tin atom in the complex 314 G. M. Bancroft and T. K. Sham, J.C.S. Dalton, 1976, 467. 315 E. Colomer, R. Corriu, and A. Vioux, J.C.S. Chem. Comm., 1976, 175. ' l h M. C. Couldwell and J. Simpson, J.C.S. Dalton, 1976, 714. 317 H. Preat and H. J. Haupt, 2. anorg. Chem., 1976, 422, 47. 318 W. K. Dean and W. A. G. Graham, J. Organornetallic Chern., 1976, 120, 73. R. D. Adams, Inorg. Chem., 1976, 15, 169. 319 Elements of Group IV 155 Figure 23 Structure of {MeS(CH2),SMe)Mo(CO),(SnC1,)Cl] (Reproduced by permission from Acta Cryst., 1976, B32, 966) [{MeS(CH,),SMe}Mo(CO),(SnC1,)Cl]CH2C1, has quite an irregular environment. Each tin atom is co-ordinated by three chlorines, one bridging chlorine, and the molybdenum atom (Figure 23).’” The reactions of the complexes (OC),M(phos) (M = W or Mo; phos = Ph2PCH2CH2PPh2, PPh,, Ph,MeP, or PhMe,P) with Me,SnCH,I have been studied. Initially, in each reaction, the expected quater- nary phosphonium salt [-PCH,SnMe,]’ I- is formed. However, attempts to isolate these salts in pure form from common solvents were unsuccessful, due to contamination from some acetylphosphonium salts. Rates of formation increase with increasing number of methyl groups attached to The reactions between Y(NH3)2 (Y=O, S, or Se; M=Si or Ge) and truns- PtX(H)(PEt,), (X = C1, Br, or I) have been investigated by n.m.r. spectroscopy. When X = Br or I and M = Si, trans-PtX(PEt,),(H,SiYSiH,) and truns- {PtX(PEt,),(SiH,)}Y are formed. For M = Ge the reactions are similar, but the products are unstable. When X=C1, S(SiH,), and Se(SiH,), give truns- PtH(PEt,),(YSiH,) and truns-PtCl(PEt,),(SiClH,). For M = Ge, the reactions are complicated, and the products thermally unstable. The reaction between H,SiSH and truns -PtHI(PEt,), gives trans-PtI(PEt,),(SiH,SH); and with truns -PtCl(H)- (PEt,),, the trans-PtCl(PEt,),(SiClH,) and trans-PtCl(PEt,),(SH) are formed.322 The reaction between NH(SiH,), and trans -PtHI(PEt,), gives trans -PtI(PEt,),- (H,SiNHSiH,) and trans-(PtI(PEt,),(SiH,)},NH. With N(SiH,),, only truns- PtI(PEt,), {H2SiN(SiH3),) is formed. With PH2(SiH3) or PH(SiH,),, PH3 and trans-PtI(PEt,),(SiH,) are produced. P(SiH3), reacts with a four-fold excess of truns-Pt(H)I(PEt,), to give PH, and trans-PtI(PEt,),(SiH,), but with reacting ratios phosphine:Pt of between 1 : l and 2:1, the products are truns- PtI(PEt,),{HSiP(SiH,),} and truns-{PtI(PEt3)2(SiH2)}2PSiH3.323 The reaction of 1,4-dihydro-octaphenyltetrasilane, H,Si,Ph,, with (Ph3P),PfC2H4 produces the first example of a transition metal incorporated into a silicon ring, i.e. 320 R. A. Anderson and F. W. D. Einstein, Acta Cryst., 1976, B32, 966. 321 R. L. Kreiter and E. W. Abel, J. Organometallic Chem., 1976, 107, 73. 322 E. A. V. Ebsworth, J. M. Edward, and D. W. H. Rankin, J.C.S. Dalton, 1976, 1667. 323 E. A. V. Ebsworth, J. M. Edward, and D. W. H. Rankin, J.C.S. Dalton, 1976, 1673. 156 Inorganic Chemistry of the Main-Group Elements Figure 24 Structure of trans -[PtCl{Si(OCH,CH,),N}(PMe,Ph),] (Reproduced from J.C.S. Chem. Cornrn., 1976, 317) (Ph,P)2-SiPh2.324 The structure of the silatrane-platinum complex trans- [PtCl(Si(OCH,CH,),N)(PMe,Ph),] is shown in Figure 24. Unlike alkyl-silatranes, there is no Si-N bond.325 (Ph3P),Pt and (Ph,P),Pd insert into Hg-Ge and Hg-Sn bonds of (C,F,),MHgM(C,F,), compounds to afford new ones that contain chains of four metal atoms, (C6F5)3M-Hg-M'(PPh3)2-M(C6Fs)3 (M = Ge or Sn; M'=Pt or Pd). The reaction of (PPh,),Pt with (C6F5),GeHgSn(C6F5), and (C,F,),GeHgEt yields (C6F,)3GeHgPt(PPh,)2sn(C6F~) and (C,F,)&ePt- (PPh,),HgEt, respectively. Most of the products were isolated as benzene sol- vates.,,, Triorgano-tin chlorides react with Pt(o) complexes to give products of insertion into the Sn-C bond rather than the Sn--Cl bond, as had been reported previously. Thus, products of the type cis-PtR1(PPh,),(SnRzX) are obtained from the reaction of Pt(C,H,)(PPh,), and R'RzSnX (R', R2=alkyl or aryl; X = halogen).,,' The reaction of DMSO with either aqueous (3N-HCl) or non- aqueous (alcohol, acetone) solutions of a mixture of K,PtCl, and excess SnCI, afforded the sparingly soluble complex [Pt{Sn(DMSO)Cl,},]Cl,, which behaves as a 1 : 2 The hydrogenation of C2H4 in acetone, which is catalysed by (NMeJ 3 [Pt(SnCI,),], at 0-15 "C and pressures up to 100 Torr, has been studied kineti- cally and spectroscopically. The data revealed that cluster complexes of various size are dispersed in solution, and it was shown that complexes containing one and 324 M. F. Lemanski and E. P. Schram, Inorg. Chem., 1976, 15, 1489. 325 C. Eaborn, K. J. Odell, A. Pidcock, and G. R. Scollary, J.C.S. Chem. Cornrn., 1976, 317. 326 V. I. Sokolov, V. V. Bashilov, 0. A. Reutov, M. N. Bochkarev, L. P. Maiorova, and G. A. Razuvaev, 327 C. Eaborn, A. Pidcock, and B. R. Steele, J.C.S. Dalton, 1976, 767. 32g P. G. Antonov, Yu. N. Kukushkin, A. N. Shanko, and L. V. Konovalov, J. Gen. Chem. (U.S.S.R.), J. Organometallic Chem., 1976, 112, C47. 1976, 46, 407. Elements of Group IV 157 six platinum atoms are responsible for the respective rate maxima observed at catalyst concentrations of 1.0 X and 5.0 x lo-, mol dm-3.329 Triaryloxy- stannyl-transition metal complexes have been synthesized by substitution of trans-M(PEt,),X, (M = Pt or Pd; X = C1or Br).,,' The tetramethylammonium salt of trichlorotris[trichlorostannate(r~)]rhodate(~~~), (Me4), [Fth(SnCl,),CI,], has been prepared by treating RhCl, with SnCl, in HCl solution. The complex rapidly exchanges with bromide ion in HCI solution to give the [€UIB~,(S~C~,),]~- ion.331 The crystal structure of CS~(R~[S~F,(H~O)~]~[S~~F~~~),~H~O is shown in Figure 25. The rhodium atom is co-ordinated by six tin atoms, two cis-SnF,(OH,), Figure 25 Structure of Cs4{Rh[SnF2(M,0),],[Sn4Fl,1),4H20 [Reproduced by permission from Proc. Acad. Sci. (U.S.S.R.), 1975, 224, 6171 groups, and the quadridentate Sn4F,, ligand in the remaining octahedral sites. Four of the tin atoms have highly distorted trigonal-bipyramidal co-ordination, whilst the other two have highly distorted octahedral co-~rdi nati on.~~~ The kinetics of the reaction (8), where M = Si, Ge, or Sn, have been studied. All ?bee reactions proceed by predissociation of the iridium complex and concerted cis-addition of Ph,MH to the square-planar intermediate.333 Ir(H)(CO)(PPh,), +Ph3MH IrH,(CO)(PPh,),(MPh,) +PPh3 (8) Bivalent Derivatives of Silicon, Germanium, Tin, and Lead.-A priori electronic structure theory has been applied to the lowest ,B,, 'A,, and ' B1 states of SiH,. The 'A, state is predicted to lie below the ,B1 state by 10 kcal rn01-l .~~~ The kinetics of formation of dimethylsilylene from Me,SiSiMe,X (X=C1 or H) and from HMe,SiSiMeH,, of methylchlorosilylene from Cl,MeSiSiMe,Cl and MeC1,- SiSiMeCI,, and of methylsilylene from H2MeSiSiMeH2 in the gaseous phase have been meas ~r ed. ~~~. ~~~ The thermolysis of the silyacyclopropyl derivative (1 8) at Me,C, I SiMe, Me,C' (18) H. Nowatari, K. Hirabayashi, and I. Yasumori, J.C.S. Faraday I, 1976, 7 5 2785. 329 330 D. R. Coulson and L. P. Seiwell, Inorg. Chem., 1976, 15, 2563. 331 T. Kimura, E. Miki, K. Mizumachi, and T. Ishimori, Chem. kt t ers, 1976, 1325. 332 T. S. Khodashova, V. A. Varnek, E. N. Yurchenko, and M. A. Porai-Koshits, plulc. Acad. Sci. 333 J. P. Pawcett and J . F. Harrod, Canad. J. Chem., 1976, 54, 3102. 334 J . H. Meadows and €3. F. Schaeffer, J. Amer. Chem. Soc., 1976, 98, 4383. 335 I. M. T. Davidson and J. J . Matthews, J.C.S. Faraday I, 1976, 72, 1403. 336 I. M. T. Davidson and M. E. Delf, J.C.S. Faraday I, 1976, 72, 1912. (U.S.S.R.), 1975, 224, 617. 158 Inorganic Chemistry of the Main - Group Elements 60-80 "C yields dimethylsilylene, which may be trapped by cis- and trans-oct-4- ene, cyclo-octene, propenyltrimethylsilane, and trh~~ethylethylethylene.~~~ Reac- tions of recoil 31Si atoms with PF3 result in the formation of both singlet and triplet 31SiF2, in the ratio 1.0:3.3. Singlet 31SiF, reacted with butadiene to give difl~oro[~~Si]silacyclopent-3-ene, but triplet 31SiF, only gave this product in the presence of paramagnetic molecules such as NO, NO2, or 02.338 Light yellow polymeric (GeCl,), has been prepared by the reaction of ger- manium metal and gaseous germanium(w) chloride in a flow system at 370- 400 "C under a germanium(rv) chloride pressure of 1 Torr. The product con- densed on the walls of the reaction system at room temperature. The molecular composition of the gas over the sample of (GeCl,), was studied at different temperatures by mass and i.r. spectrometry. The former technique indicated that the only volatile components are GeC1, and GeCl,, and that increasing the temperature from 20 to 80°C changed the ratio of GeC1, to GeC1, from 2.5 to 6.8. The concentration of GeC1, could also be decreased by lengthening the time spent by the sample in the spectrometer, An electron-diffraction study of the mixture yielded a value of 107*5" for the ClGeCl valence angle.339 The struc- tures of several tin(n) halogen compounds have been reported. The structure of SnF, has been rein~estigated.~,' The lattice contains cyclic Sn,F, tetramers, held to each other by weaker Sn-F interactions. The tetramers consist of puckered eight-membered rings with alternating tin and fluoride atoms strongly bonded together. Four more fluorine atoms are strongly bonded externally to the four tin atoms of the ring. Each tin atom forms the apex of a trigonal pyramid with three near fluorines at the base (Figure 26). The structure of SnClF is very similar to F S N Figore 26 Asymmetric unit of SnF, projected along the b-axis (Reproduced by permission from Inorg. Chem., 1976, 15, 762) 337 D. Seyferth and D. C. Annarelli, J. Organometallic Chem., 1976, 117, C51. 338 0. F. Zeck, Y. Y. Su, G. P. Gennaro, and Y. N. Tang, J. Amer. Chern. Soc., 1976,98, 3474. 339 E. Vadja, I. Hargittai, M. Kolonits, K. Ujszaszy, J. Tamas, A. K. Maltsev, R. G. Mikaelian, and M. Nefedov, J. Organometallic Chem., 1976, 105, 33. R. C. McDonald, H. H. K. Hau, and K. Erik, Inorg. Chern., 1976, 15, 762. 0 0 F S N , Figore 26 Asymmetric unit of SnF, projected along the b-axis (Reproduced by permission from Inorg. Chem., 1976, 15, 762) 337 D. Seyferth and D. C. .Annarelli, J. Organometallic Chem., 1976, 117, C51. 338 0. F. Zeck, Y. Y. Su, G. P. Gennaro, and Y. N. Tang, J. Amer. Chern. Soc., 1976, 98, 3474. 339 E. Vadja, I. Hargittai, M. Kolonits, K. Ujszaszy, J. Tamas, A. K. Maltsev, R. G. Mikaelian, and M. Nefedov, J. Organometallic Chem., 1976, 105, 33. R. C. McDonald, H. H. K. Hau, and K. Erik, Inorg. Chern., 1976, 15, 762. 0. Elements of Group IV 159 Figure 27 Structure of part of the chain of (SnClF), (Reproduced by permission from Acta Cryst., 1976, B32, 31 Figure 27 Structure of part of the chain of (SnClF), (Reproduced by permission from Acta Cryst., 1976, B32, 31 .99) that of PbC12, but the environment of the tin atom is very perturbed, mainly because of the stereochemical activity of the lone pair on the tin atom. The tin atom is co-ordinated by three fluorine and one chlorine atoms, crystals being made up of infinite double (SnClF), chains parallel to the b-axis (Figure 27).341 The crystal structure of a-'Sn,SI,', slightly deficient in SnSi is characterized by large pseudohexagonal columns of iodine atoms around mixed S and Sn positions. The remaining tin atoms are in normal trigonal prism The crystal structure of dichloro( 1,4-dioxan)tin(11) consists of SnCl, units linked by dioxan ligands in the chair conformation to form polymeric chains. The tin has pseudo- trigonal-bipyramidal geometry, with a stereochemical lone pair (Figure 28).343 ligands in the chair conformation to form polymeric chains. The trigonal-bipyramidal geometry, with a stereochemical lone pair tin has pseudo- (Figure 28).343 Figure 28 Stereochemistry at the tin atom in SnCl,,dioxan (Reproduced from J.C.S. Dalton, 1976, 1782) 341 C. Geneys, S. Vilminot, and L. Cot, Acta Cryst., 1976, B32, 3199. 342 N. H. Dung and F. Theret, Acta Cryst., 1976, B32, 1108. 343 E. Hough and D. G. Nicholson, J.C.S. Dalton, 1976, 1782. 160 Inorganic Chemistry of the Main-Group Elements Crystals of [Co(en,)][SnCl,]Cl,, prepared from [Co(en),]Cl, and SnC1,,2H,O in excess HCl, consist of [Co(en),I3' and SnC1, ions with the usual However, [CO(NH3)6][!kC14]Cl, prepared from [Co(NH,),]Cl, and SnC12 in HC1 solution that is saturated with NaCl, has a structure consisting of [CO(NH3)6]3' octahedral cations and [SnCl,]'- anions, which have the pseudo-trigonal- bipyramidal geometry, with a stereochemically active lone pair (Figure 29).345 In Figure 29 Stereochemistry of the [SnCl4l2- anion (Reproduced by permission from 2. anorg. Chem., 1976, 422, 97) crystals of NH,SnBr,,H,O, tin has five bromine atoms as nearest neighbours, four of which form a somewhat distorted square in the same plane. The tin atom is only slightly displaced from this plane, with the fifth bromine atom on the other side of the plane only 2.62A from the tin; the shortest Sn(II)-Br distance observed. The tin atom thus has a tetragonal-pyramidal geometry, and the structure may be visualized as chains of such tetragonal pyramids sharing edges parallel to the b-axis, with water molecules and ammonium ions forming rows between the chains.346 Crystals of the lead(I1) chloride-ethylenediamine complex Pb,Cl,[H,N(CH,),NH,] are built up of identical (Pb,Cc-), layers perpendicular to the a-axis and H3N(CH2),NH3 ions between layers. Each lead atom is co-ordinated by eight chlorine atoms in co-ordination polyhedra which may be described as distorted bicapped trigonal prisms around two types of lead atom and as a square antiprism about a third.347 Raman spectra for a series of basic lead(I1) chlorides have been reported. Synthetic PbCl(0H) and the mineral laurionite have identical polymeric structures. The relationship between the infinite folded- band polymeric structure of these materials and the cluster formulation of similar 344 H. J. Haupt, F. Huber, and H. Preut, 2. anorg. Chem., 1976, 422, 255. 34s H. J. Haupt, F. Huber, and H. Preut, 2. anorg. Chem., 1976, 422, 97. 346 J. Anderson, Acta Chem. Scund. (A), 1976, 30, 229. 347 I. Lijfving, Actu Chem. Scund. (A), 1976, 30, 715. Elements of Group IV 161 perchlorate compounds has been rationalized in terms of an equilibrium including small rings and linear chains.348 The reactions of CO, NO, and N2 with SnCl, and PbF,, and of CO with PbCl,, PbBr,, and PbI, in argon matrices, have been studied by i.r. spectroscopy. Ligand bands shift to higher frequency, whereas metal halide bands move to lower energy on formation of a complex.349 Several oxidative addition reactions of tin(r1) halides have been reported. Di-2-pyridyl disulphide and related compounds react to give octahedral monomeric compounds of the type X2Sn(S-py-2)2.350 Reaction with mercury(I1) or lead(w) acetates affords dihalogenotin(rv) diacetates. With diacetylenedicarboxylate diesters and diazodicarboxylate diesters, carbenoid addi- tion to the C+C and N=N multiple bonds takes place, forming cyclic tin(w) species.351 The reaction of tin(rr) chloride with carbon tetrachloride produces dichlorocarbene, which either oligomerbes or may be trapped by Me,SiCH=CH,. The reaction of ti&) bromide with CH,Br, or CHBr, produces the compounds BrCH,SnBr, and Br,CHSnBr,, which on heating eliminate tin(w) bromide to give (CH,), and (CHBr),.352 Lead(I1) dihalides form five types of adducts with uni- and bi-dentate ligands: PbX,,L, PbX2,2L, 2PbX2,L, PbX2,LL, and PbX2,2LL, but not all halides and ligands produce each type.353 The prepara- tion, properties, and vibrational spectra of Pb(NCS), complexes with 2py, phen, 2phen, tmen, en, 2en, 2DMS0, and 2DMA have been reported. The spectra are consistent with bridge-bonded and/or N-bonded i s~thi ocyanate.~~~ The structure of Pb(NCS),,2DMSO is shown in Figure 30. The lead atom is six-co-ordinate, with a distorted octahedral co-ordination sphere consisting of two nitrogen atoms and two sulphur atoms nearly coplanar with the lead atom, while two oxygen W Figure 30 Geometry at lead in Pb(NCS),,2DMSO (Reproduced from J.C.S. Dalton, 1976, 2301) 348 P. Tsai and R. P. Cooney, J.C.S. Dalton, 1976, 1631. 349 D. Tevault and K. Nakamoto, Inorg. Chem., 1976, 15, 1282. 350 M. Masaki and S. Matsunami, Bull. Chem. SOC. Japan, 1976, 49, 3274. 351 P. F. R. Ewings and P. G. Harrison, Inorg. Chim. Acta, 1976, 18, 165. 352 V. F. Mironov, V. I. Shiryaev, and V. P. Kochergin, J. Gen. Chem. (U.S.S.R.), 1976, 46, 715. 353 I. Wharf, T. Gramstad, R. Makhija, and M. Onyszchuk, Canad. J. Chem., 1976, 54, 3431. 354 A. D. Baranyi, R. Makhija, and M. Onyszchuk, Canad. J. Chem., 1976, 54, 1189. 162 Inorganic Chemistry of the Main-Group Elements atoms of the two DMSO molecules occupy the other two sites. The OPbO bond angle is only 160". The structure may be explained in terms of an irregular pentagonal-bipyramidal arrangement of six bonded atoms and one lone pair, with the latter directed towards a pentagonal corner between two sulphur atoms. Each polymeric Pb(NCS), unit behaves as a bidentate ligand with a large 'bite', forming a planar polymeric chain which extends parallel to the c-axi ~.~~' Triorgano-phosphines R,P (R = Ph, Et, dr Bu) react with equimolecular amounts of GeCl,,dioxan to give the phosphine complexes R,PGeCl,. With Bu,P, only a mixture of dioxan-stabilized and phosphine-stabilized GeCl, was ob- tai ~~ed. , ~~ The germylene complex (OC)SCr-GeCl,,THF reacts with trimethylsilylthiolates Me,SiSR to afford the thiogermylene complexes (OC)5Cr-Ge(SR),, which when treated with BCl, give (OC),CrGeC12.357 Tri-t- butylphosphine reduces germanium(rv) and tin(rv) halides to the salts [BuiPCl]' EX; (E = Ge or Sn; X = C1or Br), which with excess BuiP are in equilibrium with [BuiPX]' X- and BuiPEX,."' Phosphines react with BuiPGeX, at 20°C in benzene to afford the phosphine-stabilized germylenes R,PGeX2 (X = C1or Br). BuiP reacts directly with tin(I1) halides to give Bu\P,SnX, complexes (X=C1 or Br). HCl cleaves the Ge-P and Sn-P bonds to afford phosphonium trihalogenometal(I1) salts, whilst fast exchange occurs at room temperature with excess phosphine. Insertion of germylene into the P-CI bond occurs when GeCl,,dioxan reacts with BukPCl, giving Bu' , PG~C~, . ~~~ Trimethyltin hydroxide reacts exothermically with tin(I1) chloride in THF to give white amorphous tin(I1) hydroxide, Sn(OH),, which reacts with catechol to produce o-phenylenedioxytin(I1). The t.g.a. revealed that water is lost in two stages, slowly at 126-152°C and sharply at 195"C, leaving an orange solid containing small amounts of tin(Iv) Keto-enolato-derivatives of ger- manium(I1) of the types Ge(chel), and Ge(che1)X have been prepared by treating either GeI, or CsGeC1, with the sodium salt of the keto-enolate. The compounds are volatile, but extremely sensitive to air and The tin(I1) and lead(I1) bis(pentanedi0nates) M(acac), (M=Sn or Pb) have been obtained in very low yield from evaporation of metal and co-condensation with acetylacetone at - 196 0C.362 The reaction of bis-(0-keto-enolato)tin(II), SnX,, with Co,(CO), in benzene at room temperature yields products of composition {Co(CO),},SnX,, Co,(CO),(SnX,), or Co(CO),(SnX), depending on the nature of the p -keto- enolate residue X. Infrared data indicate that the @-keto-enolate groups chelate the tin in all cases, and also indicate that both terminal and bridging carbonyl groups are present in the compounds Co,(CO),(SnX,), and, together with the A. D. Baranyi, M. Onyszchuk, S. Forher, and G. Donnay, J.C.S. Dalton, 1976, 2301. 355 356 W. W. du Mont and G. Rudolph, Chem. Ber., 1976, 109, 3419. 357 P. Jutzi and W. Steiner, Angew. Chem. Internat. Edn., 1976, 15, 684. 358 W. W. du Mont, H. J. Kroth, and H. Schumann, Chem. Ber., 1976, 109, 3017; W. W. du Mont, B. 359 W. W. du Mont, B. Neudet, G. Rudolph, and H. Schumann, Angew. Chem. Internat. Edn., 1976,15, Neudet, and H. Schumann, Angew. Chem. Internat. Edn., 1976, 15, 308. 308. W. D. Honnick and J. J. Zuckerman, Inorg. Chem., 1976, 15, 3034. 361 A. Rodgers and S. R. Stobart, J.C.S. Chem. Comm., 1976, 52. 362 J. Blackborow, C. R. Eady, E. A. Koerner von Gustorf, A. Scrivanti, and 0. Wolfbeis, J. Organometallic Chem., 1976, 108, C32. Elements of Group IV 163 L J (19) Mossbauer data, structures (19), (20), and (21), respectively, were proposed for the three Tin(I1) bis(P-keto-enolates) are oxidized by tetracyanoethylene and 2,3,5,6-tetrachlorobenzoquinone to afford the polymeric tin(rv) derivatives (22) and (23), respectively. 7,7,8,8-Tetracyanoquinodimethane causes partial oxidation, and the mixed-valence polymeric structures (24) are obtained. Com- plexes of (C,H,),Sn with tetracyanoethylene and 7,7,8,8-tetracyanoquino- dimethane are formulated as charge-transfer complexes involving the .rr-electronic system of the cyclopentadienyl rings, whereas the complexes SnX,,tcne,THF (tcne = tetracyanoethylene; X = C1, Br, or I) and (NEt3H') (SnCl,,tcne-) are considered to contain a tin-substituted The protolysis of (C,H,),Sn by H,edaa [ =NN'-ethylenebis(acety1ideneimine)l yields Sn(edaa), the structure of CN: CN / ' ' , CN / C. \kN 363 A. B. Cornwell and P. G. Harrison, J.C.S. Dalton, 1976, 1608. 3M A. B. Cornwell, C. A. Cornwell, and P. G. Harrison, J. C. S. Dalton, 1976, 1612. 164 Inorganic Chemistry of the Main -Group Elements 0 (4') 0 I . &(16' ) , - > .. . . .. # . .. ;: C(14' )' ' . . ,;&--.::-& - - ' :o C(17') C(15') a::+' C(20') Figure 31 Structure of Sn(edaa), showing the two equivalent disordered positions of the edaa (Reproduced by permission from J. Organometullic Chem., 1976, 114, 35) which is shown in Figure 31. The geometry of the molecule is that of a square pyramid in which the tin atom lies substantially above the N,O, plane. The lone pair occupies the vacant apical site. The structure is disordered, such that half the ligand occupies equally two equivalent positions about the tin atom.179 The kinetics of the addition of diethyl hydrogen phosphite to isocyanates, when catalysed by tin(I1) octanoate, have been investigated.365 The two oxalate groups in Na,Sn(O,C,), are equivalent, and are chelated to the tin through one oxygen on each carbon, to give rise to distorted pyramidal co-ordination at tin (Figure 32)."' The structure of the mixed-valence carboxylate [Sn"Sn'v(0,CC6H4N02- ligand Figure 32 Structure of the anion in Na,Sn(O,C,), (Reproduced by permission from Actu Cryst., 1976, B32, 2098) 365 V. V. Zharkov, M. I. Bakhitov, E. V. Kuznetsov, and L. A. Reshetova, J. Gen. Chern. (U.S.S.R.), 366 J. D. Donaldson, M. T. Donoghue, and C. H. Smith, Actu Cryst., 1976, B32, 2098. 1976, 46, 790. Elements of Group IV 165 Figure 33 Structure of [Sn,(O,CC,H,NO,-o),O,THF], (Reproduced from J.C.S. Dalton, 1976, 1602) o),O,THF], is shown in Figure 33. The structure consists of independent tet- ranuclear cluster molecules containing two tin(ii) and two tin(Iv) atoms. The central feature of the macromolecule is a lozenge-shaped Sni”0, ring. Octahedral co-ordination at each tin(rv) atom is completed by oxygen atoms from four carboxylate groups, which form bridges between the tin atoms in each oxidation state. The geometry at the bivalent tin atoms is that of a pentagonal pyramid, with oxygen atoms from four carboxylate groups and the THF molecule occupying the equatorial positions. The apical site of the pentagonal pyramid is occupied by the oxygen atom of the four-membered Sn,O, ring at the extremely short tin(r1)- oxygen distance of 2.113(7) A. The lone pair presumably occupies the remaining apical position. 367 The structures of a number of tin(ii) and lead(ii) phosphates have been reported. A neutron-diffraction study of SnHPO, has shown that the HP0;- ions are linked together by two asymmetric hydrogen bonds to form dimers. The tin- phosphate-xygen co-ordination takes place primarily in layers, with the hydrogen-bonds occurring between these The structure of Sn,(OH)PO,, a reaction product of SnF, and apatite, is shown in Figure 34. Each tin atom is co-ordinated by three oxygen atoms at distances of ca. 2.1 A, with two further oxygen atoms at ca. 3.0 The structures of two lead(i1) phosphate hydrates, uiz. lead trimetaphosphate Pb3(P309),,3H20 and lead cyclotetraphosphate Pb2P401,,4H20, have been determined. The two lead sites in the former have nearly regular octahedral and seven-co-~rdination.~~~ The latter compound con- sists of cyclic P401f; anions which are connected by lead and hydrogen ions. The P. F. R. Ewings, P. G. Harrison, A. Morris, and T. J. King, J.C.S. Dalton, 1976, 1602. T. H. Jordan, L. W. Schroeder, B. Dickens, and W. E. Brown, Inorg. Chew., 1976, 15, 1810. M. Brunei-Laiigt, I. Tordjman, and A. Durif, Acru Cryst., 1976, B32, 3246. 367 368 L. W. Schroeder and E. Prince, Actu Cryst., 1976, B32, 3309. 369 370 166 Inorganic Chemistry of the Main - Group Elements Figure 34 Environments of tin ions in Sn,(OII)PO, (Reproduced by permission from Inorg. Chern., 1976, 15, 1810) lead atom is eight-co-~rdinate.~~~ Pure polymeric Pb(OPPh,O), has been ob- tained by the reaction of lead(I1) nitrate, Ph,P(O)OH, and Na,CO, in water, and has a structure consisting of chains of lead atoms linked by double phosphinate bridges (Figure 35). The co-ordination around each lead atom can be described as a distorted trigonal bipyramid, with the lone pair occupying an equatorial site. The polymer dissociates in solution, and the i.r. spectra suggest that changes in the mode of co-ordination of the phosphinate groups take place on The geometries at the metal in tin(I1) bis( O-methyldithi~carbonate)~~~ and [Ph,P][Sn,(WS,),]374 are that of a distorted trigonal bipyramid (with a lone pair occupying an equatorial site) and highly distorted octahedral, respectively (Figures 36 and 37). The latter complex anion contains two such distorted octahedra coupled by a common edge, with the tin atom co-ordinated by two bidentate and two unidentate WS, ligands. In the Pb-S-0 system there are eight monovariant equilibria, of which five are independent. The measurement of SO, pressures at different temperatures permitted the evaluation of standard free energies of formation for PbS04,4Pb0, PbS04,2Pb0, PbSO,,PbO, and PbSO,. The phase diagram of the PbS0,-PbO system has been calculated.375 Only GeAsSe is formed when GeSe and As are heated at 580°C for 2 hours. A mixture of GeAsSe and GeAs4Se results when excess As is used, but mainly the latter phase is obtained when a 1:4 stoicheiometry is used, at 600°C for 12 Amorphous GeTe can be made to crystallize by applying pressure (up to 120 kbar) at temperatures in excess of 300 "C. The known rhombic phase and also H. Worzala, Z. anorg. Chem., 1976, 421, 122. 371 372 P. Colarnarino, P. L. Orioli, W. D. Benzinger, and H. D. Gillman, Inorg. Chern., 1976, 15, 800. 373 P. F. R. Ewings, P. G. Harrison, and T. J. King, J.C.S. Dalton, 1976, 1399. 374 A. Miller, I. Paulat-Boschen, B. Krebs, and H. Dornfeld, Angew. Chern. Internat. Edn., 1976, 15, 375 2. Derriche and P. Perrot, Rev. Chim. minerule, 1976, 13, 310. 376 K. E. Pachali, J. Puska, and H. Thura, Inorg. Chern., 1976, 15, 991. 633. F i g u r e 3 5 P o l y m e r i c c h a i n s t r u c t u r e o f P b ( O P P h , O ) , ( R e p r o d u c e d b y p e r m i s s i o n f r o m I n o r g . C h e r n . , 1 9 7 6 , 1 5 , 8 0 0 ) 168 Inorganic Chemistry of the Main-Group Elements Figure 36 Structure of Sn(S,COMe), (Reproduced from J.C.S. Dalton, 1976, 1399) a new orthorhombic phase are He (I) photoelectron spectra of GeS, GeSe, SnS, SnTe, and PbTe in the gaseous phase have been obtained by photoionization of the vapours above the appropriate solids at temperatures of 700-1000 K.378 Dicyclopentadienyltin(I1) and bis(methylcyclopentadienyl)tin(II) form complexes of composition R,Sn=M(CO), (M = Cr, Mo, or W) with M(CO),THF complexes in THF. With Fe,(CO), the four-membered Sn,Fe, ring compounds [(OC),FeSn(C5H5)2]2 will dissociate, in the presence of pyridine, to give (OC),FeSn(C,H,),,(C,H,N) complexes. Only Sn[Co(CO),], could be isolated from the reaction between (MeC,H,),Sn and CO,(CO),.~~~ Similar complexes of P d W Figure 37 Structure of the dimeric anion [Sn,(WS,),]"- (Reproduced by permission from Angew. Chem. Internat. Edn., 1976, 15, 633) 377 M. Shimida and F. Dachille, Innorg. Chem., 1976, 15, 1729. 379 A. B. Cornwell, P. G. Harrison, and J . A. Richards, J. Orgummetallic Chem., 1976, 108, 47. M. W u and T. P. Fehlner, J. Amer. Chem. Soc., 1976, 98, 7578. 378 Elements of Group IV 169 Figure 38 Structure of {Sn[CH(SiMe,),],}, (Reproduced from J.C.S. Chem. Comm., 1976, 261) boron and aluminium trihalides of the type R,Sn=MX, have also been ob- tai ~~ed,~~' although the reactions of boron tribromide and tri-iodide with (C,H,),Sn have been reported to give the complexes C5H5SnX,SnX2.381 Stannylene-manganese complexes Mn(MeC,H,)(CO),=SnX, (X = C1, Br, or P - diketonate) have also been obtained from SnX, and Mn(MeC,H,)(CO),THF.382 The protolysis of (C,H,),Pb by acidic reagents yields either C5H5PbX (X = C1, Br, I, or MeCO,) or PbX, (X=Bu', P-keto-enolate, or alkoxide) compounds, de- pending on HX. The cyclopentadienyl-lead halides were thought to be polymeric, with bridging halide ions.383 Two methods have been described for the synthesis of the metal(I1) alkyls M[CH(SiMe,),I2 (M=Ge, Sn, or Pb), from metal(I1) chloride (M=Sn or Pb) or M[N(SiMe,),] (M = Ge or Sn) and LiCH(SiMe,) in ether at 0 to -20 0C.384y385 At ambient temperatures the solutions are yellow (Ge), red (Sn), and purple (Pb). The compounds are monomeric, and in the singlet electronic state. Colour changes occur between the solid and melt, and the compounds tend to become colourless at -196 "C. The crystal structure of the tin compound is a centrosym- metric dimer, with a Sn-Sn distance of 2.76 A; similar to that in Ph,Sn, (Figure 38). The germanium compound was inferred to have a similar structure from its vibrational spectral data. The monomer is believed to be angular, with sp2 hybrid orbitals at the metal (25), whilst R ' s n a / R (25) 380 P. G. Harrison and J. A. Richards, J. the dimer, with a Sn=Sn bent double bond, is (26) Organometallic Chem., 1976, 108, 35. W. Siebert and K. Kinberger, J. Organometallic Chem., 1976, 116, C7. 381 382 A. B. Cornwell and P. G. Harrison, J.C.S. Dalton, 1976, 1054. 383 A. K. Holliday, P. H. Makin, and R. J. Puddephatt, J.C.S. Dalton, 1976, 431. 384 D. E. Goldberg, D. H. Harris, M. F. Lappert, and K. M. Thomas, J.C.S. Chem. Comm., 1976,261. 385 P. J. Davidson, D. H. Harris, and M. F. Lappert, J. C. S. Dalton, 1976, 2268. 170 Inorganic Chemistry of the Main -Group Elements [M(CO),(SnR,)] + trans -[M(CO),(SnR,),] 3 Y [RhCl(PPh&(SnR2)1 S n R , A trans-[M(CO),(SnR,),] [Fe2(.r-CsH,),(Co),(snR,)1 [PtCl(PEt,)(SnR,)(SnR,Cl)] /\ Reagents: i, [RhCl(PPh,),]; ii, [Rh(C2H4)Cl(PPh3)2]; iii, [{PtC12(PEt3)}2]; iv, [M(CO)J (M =Cr or Mo); v, [M(C0)4(norbornadiene)] (M =Cr or Mo); vi, [{Fe(q-C5Hs)(C0)2}2] Scheme 5 formed by overlap of the non-bonding orbital of each monomer unit with the orthogonal vacant p,-orbital of the other (26).385 The compound has an extensive chemistry, and it functions as both a Lewis acid and a Lewis base, and also undergoes oxidative addition (insertion reactions). Many of the reactions are summarized in Schemes 5 and 6.3863387 Mossbauer data for several of the tin compounds have been reported and whilst He (I) photoelectron [Mo(.r -C5H,)(CO),(SnMeR2)1 SnBr2R, SnR,Cl,, and SnRCl, [PtCl(PEt,)(SnX,)(SnR,Cl)] vii ‘ Fe( CO), [FeMe(q-C,H,>(CO),]; vi, [{PtC12(PEt3}2]; vii, [Fe2(C0)9]; viii, HC1; ix, [NH~IIEHFZI; x, MeI; xi, RCl; xii, CC14; xiii, Br2; xiv, C12; xv, O2 or NO Scheme 6 386 J . D. Cotton, P. J. Davidson, and M. F. Lappert, J.C.S. Dalton, 1976, 2275. 387 M. J . S. Gyane, M. F. Lappert, S. J . Miles, and P. P. Power, J.C.S. Chem. Comm., 1976, 256. ”* J . D. Cotton, P. J . Davidson, M. F. Lappert, J . Donaldson, and J . Silver, J.C.S. Dalton, 1976, 2286. Elements of Group IV 171 spectra for the metal(r1) alkyls and amides, MR2 and M(NR& (M=Ge, Sn, or Pb), have been The hydrolysis of tin(r1) has been studied by means of potentiometric titration at low tin(n) concentrations (0.02-2.3 mmol l-l) in the pH range 2.7-3.7. The e.m.f. data could be rationalized by the equilibria (9) and Rate constants have been obtained for the reduction of the cations Ta,Cl:,' and [TaSCl l 2~ by Sn2' and for the reaction of Fe3' with [Ta&11z]3'. The data have been used to interpret the catalysis of the reaction between Sn2+and Fe3' by the [Ta&l1J3+ cation in aqueous The reaction of lead ions [as Pb(NO,),] with ClO, ions in fused NaClO, at 300-320°C gives 02, Clz, PbOz, and Cl-.392 The methylation of Pbz+by a methylcobalt complex in prop-2-en01 has been discuss- ed. The lead product, MePb', is unstable, and it decomposes with a half-life of 60.1 h.393 Figure 39 Crystal structure of [Na,,7en]Sn9 in projection parallel to [OOl ] (Reproduced by permission from Chern. Ber., 1976,109, 3404) 389 D. H. Hams, M. F. Lappert, J. B. Pedley, and G. J. Sharp, J.C.S. Dalton, 1976, 945. 390 S. Gobom, Acra Chem. Scand. (A), 1976, 30,745. 391 D. M. Haynes and W. C. E. Higginson, J.C.S. Dalton, 1976, 309. 392 Z. Kodejs and I. Slama, Coll. Czech. Chem. Comm., 1976, 41, 1121. 393 M. W. Witman and J. H. Weber, Inorg. Chem., 1976, 15, 2375. 172 Inorganic Chemistry of the Main-Group Elements Figure 40 ( a) The structure of the Sn:- union; ( b) The structure of the Pbg- anion (Reproduced from J.C.S. Chern. Comm., 1975, 984) Subvalent Chemistry.-Using the M.O. method, a study of the equilibrium distances, force constants, and binding energies of the diatomic species C2, Si2, Ge,, and Sn, has been made. In addition, the tetrahedral clusters of these atoms were investigated in an attempt to determine bulk lattice parameters and stretch- ing force constants.394 The stabilities of the ligand-free tin clusters Sn,-Sn,395 and the ligand-free tin-gold clusters SnAu, Sn,Au, SnAu,, Sn2Au2, and Sn3A~396 have been investigated by mass spectrometry. Similar techniques have been used to study the stabilities and thermodynamic properties of the Pb,, Pb3, and Pb, species.397 Alloys of sodium with germanium, tin, or lead, when treated with ethylenediamine, yield stable solutions of Zintl’s so-called ‘polyanion salts’, from which the crystalline compounds (Na4,7en)Sn, and (Na,,Sen)Ge, were obtained. The former material contains the Sn:- ion, which has a geometry between the ideal geometries of tricapped trigonal prism and an antiprism capped on one side (Figure 39).398 This anion has also been characterized as its salt with the Na(2,2,2-cryptate) cation (Figure 40a).399 The Pbz- anion has similarly been obtained (Figure 40b).399 394 A. B. Anderson, J. Chem. Phys., 1975, 63, 4430. 39s K. A. Gingerich, A. Desideri, and D. L. Cocke, J. Chem. Phys., 1975, 62, 731. 396 K. A. Gingerich, D. L. Cocke, and U. V. Choudary, Inorg. Chirn. Actu, 1975, 14, L47 397 K. A. Gingerich, D. L. Cocke, and F. Miller, J. Chem. Phys., 1976, 64, 4027. 398 L. Diehl, K. Khodadadeh, D. Kummer, and J. Strahle, Chem. Ber., 1976, 109, 3404. 399 J. D. Corbett and P. A. Edwards, J.C.S. Chem. Comm., 1975, 984. 5 Elements of Group V BY N. LOGAN AND D. 6. SOWERBY 1 Nitrogen Elemental Nitrogen.-Reactions of N,. Nitrogen reacts with solutions of barium in liquid sodium (ca. 4.40 mol.% Ba) at 300°C up to a solution composition approximating to Ba,N, beyond which the quantity of dissolved N2 decreases progressively due to the precipitation of Ba,N. The results have been interpreted in terms of strong preferential solvation of nitride ion by Ba2+.' The solubility of nitrogen in liquid lithium has been determined at 195-441 "C, over solid Li3N. The relationship (l), where S is the mol.% Li3N, was thereby established.2 log S=3.373-2107(T/K)-l (1) Reactions of tin(I1) chloride and lead(r1) fluoride with the ligands N,, NO, and CO, in argon matrices, have been studied by i.r. spectro~copy.~ The magnitude of the shifts in the metal halide and in the ligand bands when a complex is formed was used as a measure of the extent of c+-donation from the ligand to the metal. The effects on cr-donation of changing the ligand, halogen, and metal were discussed on the basis of the observed shifts. Changes in the composition of the solid product (containing AlN and Si3N4) obtained from the reaction of aluminium and silicon with nitrogen in a plasma jet of a high-frequency discharge have been studied as a function of several experi- mental variable^.^ Reactions involving the reduction (fixation) of molecular nitrogen, and its use in the synthesis of dinitrogen complexes of transition metals, continue to attract attention. Shilov and his co-workersS-' have studied the reduction of nitrogen in three different systems. The addition of LiBr accelerates the reduction of nitrogen in ' C. C. Addison, R. J. Pulham, and E. A. Trevillion, J.C.S. Dalton, 1975, 2082. R. M. Yonco, E. Veleckis, and V. A. Maroni, J. Nuclear Materials, 1975, 57, 317. D. Tevault and K. Nakamoto, Inorg. Chem., 1976,15, 1282. G. Heidemane, Tezisy Dok1.-Konf. Molodykh Nauchn. Rab. lnst. Neorg. Khim. Akad. Nauk Law. S.S.R., 4th, 1975, 38 (Chem. Abs., 1976, 84, 68946). B. Chubar, A. E. Shilov, and A. K. Shilova, Kinetika i Kataliz, 1975, 16, 1079. V. V. Abalyaeva, N. T. Denisov, L. M. Khidekel, and A. E. Shilov, lzvest. Akad. Nauk S.S.S.R., Ser. khim., 1975, 2638. L. A. Nikonova, N. I. Pershikova, S. A. Isaeva, A. G. Ovcharenko, and A. E. Shilov, Tezisy Dok1.-Vses. Chugaevskoe Soveshch. Khim. Kompleksn. Soedin., 12th 1975,2, 184 (Chem. Abs., 1976, 85, 171 049). 173 174 Inorganic Chemistry of the Main- Group Elements the FeC1,-LiPh-N, system, and LiCl and LiPh exhibit a similar but weaker effect.' The effect of the additives is explained by the electrophilic effect of Li compounds, which provide electron transfer to the nitrogen molecule in an intermediate complex with a low-valent iron derivative. Hydrogen reduces solutions containing Ti4' and M0'+to Ti3+and Mo3' in the presence of a hydrogenation catalyst in an acidic medium; during subsequent alkalization and formation of hydroxide salts of the Ti3'-Mo3' system in the presence of Mg salt as an activator, N2 is reduced to N2H4. At pH 9-10 and at 50 "C in the Ti4'-Mo5'-Mg2+ catalyst system, N2 is reduced by H, to NH3, N2H4 being formed as an intermediate product.6 The ability of vanadium(I1)-polyphenol complexes to react with N2 depends on the nature of the polyphenol. In the V"-pyrocatechol (or -4-methylpyrocatechol) system, the optimum yield of NH3 from N, occurs at pH 10, whereas complexes of V" with pyrogallol (or gallic acid) reduce nitrogen only in strongly alkaline solution^.^Two further investigation^^'^ have been carried out on a nitrogen-fixing system formed on reduction of TiC13,3THF by magnesium in THF in an argon atmosphere. The resulting complex, formulated as Ti(MgCl),,TiCl,, reacts with nitrogen to give Ti(MgC1),(N2),TiCl2. The latter rearranges to Ti-Mg nitride species, which yield NH3 upon hydrolysis.8 The effects of PrCl as oxidizing agent and PrMgCl and Na as reducing agents on the nitrogen-fixing properties of Ti(MgC1),,TiC12 were also studied.' A variety of reducible substrates, including molecular N,, act as in- hibitors of formation of molecular H2 from aqueous suspensions of Fe(OH),, and the reduction of these substrates occurs in a manner typical of reactions of highly dispersed elemental Fe. With molecular N,, hydrazine and ammonia are formed." The synthesis of novel transition-metal complexes, using molecular N, to supply dinitrogen ligands, continues, and has been reported this year for V, Mo, Fe, and Co species. The compounds V(N,), and V2(N2). (where n is probably 12) have been synthesized directly by co-condensation of vanadium atoms with pure N2 and investigated by i.r, and u.v.-visible spectroscopy. Dinitrogen has been shown to be a strong-field ligand in its bonding properties, and the intriguing observation that atomic vanadium can be isolated in N2 matrixes from 8-10 K codepositions, yet V(N2)6 is preferentially formed at 20-25 K, has been discussed in terms of the subtle temperature dependence of product yield when performing direct syntheses with metal atoms.ll [MoC1,L3] (L = THF) reacts with phosphines and magnesium or sodium amalgam in the presence of N2 to give Moo complexes, including [Mo(N,),(PMe,Ph),] and [Mo(N,),(dpe),]12 [dpe = 1,2-bis(diphenyl- phosphino)ethane]. The complex [Mo(CO)(L)(dpe),] (L = dimethylformamide) reacts readily with nitrogen gas to form the dinitrogen complex trans-[Mo(CO)- (N,)(dpe),], but the N2 ligand is labile.', The reaction of [Fe(1,5-C8Hl2),] (C8H12 = cyclo-octadiene) with dpe and N2 yields the complex [Fe(N2)(dpe),].14 The reduction of CoC12-Me3P in THF by magnesium turnings, using N2 as the S. Tyrlik and I. Wolochowicz, Bull. Acad. polon. Sci., Ser. Sci. chim., 1976, 24, 341. S. Tyrlik and I. Wolochowicz, Bull. Acad. polon. Sci., Ser. Sci. chim., 1976, 24, 349. H. Huber, T. A. Ford, W. Klotzbuecher, and G. A. Ozin, J. Amen Chem. SOC., 1976, 98, 3176. lo G. N. Schrauzer and T. D. Guth, J. Amer. Chem. SOC., 1976, 98, 3508. l2 M. W. Anker, J. Chatt, G. J. Leigh, and A. G. Wedd, J.C.S. Dalton, 1975, 2639. l3 T. Tatsumi, H. Tominaga, M. Hidai, and Y. Uchida, J. Organornetallic Chem., 1976, 114, C27. l4 R. A. Cable, M. Green, R. E. Mackenzie, P. L. Timms, and T. W. Turney, J.C.S. Chem. Comm., 1976, 270. Elements of Group V 175 Figure 1 The structure of [(M~,P),CO(N~)M~(THF),(N~)CO(M~,P)~]; bond lengthslpm (Reproduced by permission from Angew. Chew. Inremat. Edn. , 1976, 15, 612) protective gas, ,yields, under appropriate conditions, the novel hetero-bimetallic dinitrogen complex [(M~,P>,CO(N,)M~(L),(N,)CO(M~~P)~] (L = THF).” The structure of this product has been determined by X-ray methods, and it contains a centre of symmetry (Figure 1). The composition of this hetero-bimetallic system shows some resemblance to a class of new alkali-metal-dinitrogen complexes reported recently by Jonas.16 Complexing of NZ. A number of other studies of syntheses (not involving molecular N2) and properties of transition-metal complexes incorporating the dinitrogen ligand have been reported during the year. Detailed consideration of these aspects of transition-metal chemistry is inappropriate in this volume; however, brief details of these papers, subdivided under three headings, are given in Table l.17-31 Nitrides.-The solubility study of nitrogen in liquid lithium’ also yielded results on the thermal decomposition of solid lithium nitride. The problems encountered in the nitridation of Sr and Ca to the stoicheiometric M3N2 are explained by the presence of hydrogen in the starting metals, which leads to the formation of non-stoicheiometric nitride hydrides, until now assumed to be Ca2N and Sr,N. The so-called SrN, which is formed only in the presence of oxygen is, in fact, a NaC1-type cubic quaternary phase that is rich in N and of variable composition R. Hammer, H. F. Klein, U. Schubert, A. Frank, and G. Huttner, Angew. Chem. Internat. Edn., 1976, 15, 612. K. J onas, Angew. Chem. Internut. Edn. , 1976, 15, 47. I. A. Tikhonova, V. B. Shur, and M. E. Vol’pin, Izvest. Akad. Nauk S. S. S. R. , Ser. khim., 1976, 229. J . Chatt, A. J . Pearman, and R. L. Richards, J. Organometallic Chem., 1975, 101, C45. 15 16 ’’ F. Bottornley, E. M. R. Kiremire, and S. G. Clarkson, J.C.S. Dalton, 1975, 1909. l9 T. Tatsumi, M. Hidai, and Y. Uchida, Inorg. Chem., 1975, 14, 2530. 21 J . Chatt and J. R. Dilworth, J.C.S. Chem. Comm., 1975, 983. 22 K. R. Laing, R. L. Leubner, and J . H. Lunsford, Inorg. Chem., 1975, 14, 1400. 23 A. C. J esse, J . F. Van Baar, D. J . Stufkens, and K. Vrieze, Inorg. Chim. Actu, 1976, 17, L13. 24 M. Aresta and C. F. Nobile, Inorg. Chim. Actu, 1976, 17, L17. 25 D. Sellmann, A. Brandl, and R. Endell, J. Organometallic Chem., 1976, 111, 303. 26 D. C. Busby and T. A. George, J. Organometallic Chem., 1976, 118, C16. ’’ P. C. Bevan, J . Chatt, R. A. Head, P. B. Hitchcock, and G. J . Leigh, J.C.S. Chem. Comm., 1976, ’* J . Chatt, J . P. Lloyd, and R. L. Richards, J.C.S. Dulton, 1976, 565. 29 I. I. Zakharov, V. I. Avdeev, and A. I. Boldyrev, Doklady Akad. Nuuk S. S. S. R. , 1975, 225, 126. 30 C. Parlog, A. Alistar, D. Negoiu, and D. Sandulescu, Rev. Chim. (Bucharest)., 1975, 26, 200. 31 V. M. Sobolev, I. B. Golovanov, and M. V. Vol’kenshtein, Teor. i eksp. Khim., 1976, 12, 330. 509. 176 Table 1 Studies of transition- metal-dinitrogen complexes Inorganic Chemistry of the Main-Group Elements Synthesis and properties [Ru(NH3)J N2)I2+from {Ru(NH,),(NO)I3+and OH- [Ru(NH3),(N,)I2+and [(NH3)5Ru(N2)Ru(NH3)s]4f from [RU(NH~)~H,O]~+ and ethyl diazoace tate trans-[Mo(N2)(4-XC,H4CN)(dpe),l [X =NH,, MeO, Me, H, C1, or C(0)Me; dpe = 1,2-bis(diphenylphosphino)ethane] from trans-[Mo(N,),(dpe),] and vari- ous para-substituted benzonitriles Reactivity Complexes of Mo and W containing N,H, N,H,, and N2H3 ligands, obtained [Mo(N,),(dpe),] with Me3SiN, as a route to Mo imido- and nitrido-complexes 1.r. and reactivity studies of dinitrogen complexes of Ru and 0 s in Y-type zeolites [IrCl(N,)(PPh,),] with SO, trans-[Mo(N,),(dpe),} with various acids and with [NiLiX], (L' =tricyclohexyl- phosphine; X = C1or Br) Ligand properties and reactivity of dinitrogen, di-imine, hydrazine, and ammonia in pentacarbonylchromium(o) complexes [Mo(N,),(dpe),] with XCH,CO,Et (X =C1, Br, or I) [W(N,),(dpe),] with THF Mo-dinitrogen complexes with thiols and sulphenyl halides from N, complexes Structure and electronic properties Nature of activation of molecular nitrogen in complexes Crystal structure, electronic and i.r. spectra, and magnetochemistry of metal-N, Models of complexes of molecular N, with compounds of TiX, (n=2 or 3; complexes (review) X =halogen) type Ref. 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 SrN,-,,H,,nSrO ( n = 0.02-0.08); the reaction of Ca,N, with CaO in the pres- ence of hydrogen gives analogous quaternary The synthesis of a -Si3N4 by reduction of high-purity amorphous Si 02 with high-purity lampblack carbon in a nitrogen atmosphere has been studied, using various thermal treatments and compositions. At 1400-l45O0C, Si3N, was formed, but at 1500°C Si c was apparently produced. The formation of Si,N4 was considerably affected by the initial C: Si molar ratio.33 The synthesis of silicon nitride has also been investi- gated by the introduction of fluidized, powdered Si into a jet of nitrogen previously subjected to a high-intensity arc discharge. 1.r. spectra and chemical analyses of the cooled reaction products revealed the formation of non- stoicheiometric Si-N Ge3N4 has been prepared by three different methods: the reaction of pure NH3 and powdered Ge; the reaction of gaseous NH,-H, mixtures of various compositions with powdered Ge; and the reaction of pure NH, with GeCl,, using N, as carrier gas. The products were studied by i.r. spectroscopy, and it was concluded that the preparation of pure a- and P-Ge3N4 polymorphs requires rigorous control of the composition of nitriding gas and the ternperat~re.~~ Conditions for the preparation of Ti,AlN from metallic Ti and AlN, and measurements of electrical conductivity, thermal conductivity, e.m.f ., 32 J. F. Brice, J. P. Motte, and J. Aubry, Rev. Chim. minirale, 1975, 12, 105. K. Komeya and H. Inoue, J. Materials Sci., 1975, 10, 1243. A. Szymanski, A. Huczko, and A. Podgorski, Roczniki Chem., 1976, 50, 1453. 33 34 35 J. C. Remy and Y. Pauleau, Inorg. Chem., 1976, 15, 2308. Elements of Group V 177 and the coefficient of thermal expansion of this ternary compound, have been The reactions of La, Ce, and Gd nitrides with fluorides or the pyrolysis of these fluorides in an atmosphere of NH, leads to nitride fluorides of general formula LnN, F3-3x, which crystallize with a fluorite-type Vibrational spectroscopic studies (980-1060 cm-l) of reactions of uranium atoms with NO, in argon matrices yielded the vibrational frequencies of the matrix- isolated UN molecule, the tentative identification of a linear N-U-N molecule, and the observation of an absorption peak ascribed to the U-N stretch of an unidentified molecule X-UN. None of the peaks was due to an absorber containing oxygen.38 Bonds to Hydrogen.-Ammonia. Ab initio S.C.F. theory has been applied to the complexes H3N,03 and H3N,S02 (as well as Me,N,SO,). The equilibrium strue- ture of these complexes was predicted, and, to a surprising degree, the O3 or SO2 molecule lies in a plane nearly perpendicular to the amine C3u axis. Furthermore, the central atom in 0, and SO, is predicted to lie only slightly off this axis.39 The products formed during solid-state reactions between NH, and SO, have been investigated by i.r. The adducts (H3N),,S02 and H3N,S02 were identified under appropriate low-temperature conditions in the absence of H20, whereas ammonium sulphite, pyrosulphite, or bisulphite were formed in the presence of varying amounts of H,O. It has been found that the exothermic NH3 synthesis reaction can be conducted beyond equilibrium limitations by pulsing nitrogen, with hydrogen as the carrier, through a packed bed of catalyst and adsorbant. Relatively high conversions are obtained at low press~res.~~ In alkaline solutions, NH3 that is co-ordinated to ruthenium in [Ru(NH&I3+is rapidly oxidized at room temperature, using a continual flow of air or pure oxygen, resulting in a 30% yield of the nitrosyl [Ru(NH3),(N0)I3'. Greater yields (> 70%) of this nitrosyl complex can be obtained by using alkaline peroxide solutions. This facile, room-temperature, aerial oxidation represents a dramatic improvement over conventional methods for oxidizing NH3 (> 800 "C over a Pt-Rh catalyst).,, The reactions of NH, with MGa,O, (M = Mg, Mn,Zn, Ni, or Cu), beGaO,, Ga,GeO,, CuGaO,, and FeO.,Gal.,O3 give mixtures of GaN and the oxide or nitride of the metal M, except in those cases when the temperature is low enough (usually 500-650 "C), when a new phase Gal-,/30x/3Nil-x0x (x = 0.1) can be isolated.43 The ammonolysis of triphenylcyclohexyl-lead in liquid ammonia con- taining potassium amide has been reported by Schmitz-DuMont and co-workers. The ammonolysis yields K[Pb(NH2)3], benzene, and cyclohexane, and a mechan- ism has been discussed. K[Pb(NH,),] is converted into K[Pb(NH)(NH,)] by reaction with NH3 in vacuum at room temperat~re.~~ The gas-solid reaction of 36 V. I. Ivchenko, M. I. Lesnaya, V. F. Nemchenko, and T. Ya. Kosolapova, Poroshk. Metall., 1976,60. 37 M. Pezat, B. Tanguy, M. Vlasse, J. Portier, and P. Hagenmuller, J. Solid Scare Chem., 1976,18, 381. 38 D. W. Green and G. T. Reedy, J. Chem. Phys., 1976, 65, 2921. 39 R. R. Lucchese, K. Haber, and H. F. Schaefer, tert., J. Amer. Chem. Soc., 1976, 98, 7617. 40 I. C. Hisatsune and J. Heicklen, Canad. J. Chem., 1975, 53, 2646. 41 B. D. Unger and R. G. Rinker, Ind. and Eng. Chem. (Fundamentals), 1976, 15, 225. 42 S. D. Pel1 and J. N. Armor, J. Amer. Chem. Soc., 1975, 97, 5012. 43 P. Verdier and R. Marchand, Rev. Chim. minirale, 1976, 13, 145. W. Jansen, K. 0. Nickels, H. Kessel, and 0. Schmitz-DuMont, 2. anorg. Chem., 1976, 425, 272. 44 178 Inorganic Chemistry of the Main - Group Elements NH, with TaS, has been studied in an attempt to gain a more thorough understanding of the process of intercalation of Lewis-base guests into the layered transition-metal dichal~ogenides.~~ Addition of NH3 to M[A1(BH4),] (M = Bu4N or K) in a 6 : 1 mole ratio at -196 "C, followed by warming, gave M[BH4] and [A1(NH3)6](BH4)3.46 NH, reacts with a solution of Mo(CO), in THF at 20"C, yielding [Mo(CO),NH,].~~Chloramine-T reacts with NH, at pH > 8. The pres- ence of Br- increases the rate of reaction and extends the pH range to ca. pH 9. Nitrogen was not formed quantitatively under any conditions, but unidentified chloramines and bromamines were found in the reaction head-space.,' The Ammonium Ion. The measurement of the ionization potential and mass spectral analysis of the ammonium chloride molecule at 150-200 "C and 10-4mmHg provide evidence for the non-equivalence of the N-H bonds. The molecule is considered to have a charge-transfer-type structure NH,,HCl, and the mechanism for the formation of NH3,HC1 from NH3 and HCl is With the aim of verifying whether NH,' (radius 1.45 A) can be used as a probe in place of K' (radius 1.33 A) in natural systems, certain salts NH4L [L = anion of organic acid HL, uiz. 2-nitrophenol (onpH), 2,4-dinitrophenol (dnpH), 2,4,6-trini- trophenol (picH), or 2-hydroxybenzoic acid (salH)] have been synthesized, and their reactions with HL, 1,lO-phenanthroline (phen), benzo-15-crown-5 (crown-5), and dibenzo-30-crown- 10 (crown- 10) investigated in a study of the co-ordination chemistry of NH: .'" The novel ammonium compounds NH,(L)(dnpH) (L = dnp-), NH4L(phen) (L = dnp-, sal-, or pic-), NH,L(crown-5) (L = dnp- or pic-), and (NH,L),(crown-10) (L = dnp- or pic-) were isolated in the solid state, but the results, on the whole, did not indicate that NH; is a suitable probe for K'. The reaction of ammonium chloride with zirconium metal at 30-40 kbar and 1000- 1500 "C at Zr:NH4C1 ratios of 1: 1 and 1 : 2 goes to completion in several minutes, yielding ZrN. The latter reacts further with NH4C1 at high pressure and temperature to give ZrNC1, which is hexagonal, with a = 2.08 and c = 9.23 A. Metals of Groups IIIB, IVB, and VB also react with NH4C1 to give the corresponding nitride^.^' The effect of prior mechanical and thermal treatment on the isothermal decomposition of NH4C104 has been studied5* in the temperature range 215- 235 "C, and thermal analysis on additives used in NH4N03 to prevent its agglomeration when used as fertilizer indicate that chlorides, expecially CaC1, or FeCl,, should not be used. The presence of only 0.1% of either of these salts lowers the temperature of initiation of decomposition of NH4N03 sufficiently to give a violent reaction and explosion. Data are plotted for the reactions, at 45 M. Dines and R. Levy, J. Phys. Chem., 1975, 79, 1979. 46 K. N. Semenenko, 1. I. Korobov, 0. Kravchenko, and S. P. Shilkin, Russ. J. Inorg, Chem., 1975,20, 47 D. Sellmann, A. Brandl, and R. Endell, J. Organometallic Chem., 1975, 97, 229. 48 V. J. Jennings and A. Dodson, Talanta, 1975, 22, 755. 49 T. I. Evlasheva, V. K. Potapov, and V. A. Tulupov, Zhur. fiz. Khim., 1975, 49, 1264. '' N. S. Poonia, J. Inorg. Nuclear Chem., 1975, 39, 1859. 1568. V. V. Savranskii, K. P. Burdina, A. N. Tsvigunov, and E. V. Zubova, Vestnik Moskov. Univ., Khim., 1975, 16, 246. 51 52 V. R. P. Verneker and K. Rajeshwar, J. Solid Stare Chem., 1976, 17, 27. 53 V. Panv and L. Fodor, Rev. Chim. (Bucharest), 1975, 26, 783. Elements of Group V 179 various pH values, of NH4N03 with FeCl,, CaCl,, and AlCl,. The effect of naphthenates and CuO on the decomposition of NH4N03 has also been studied, using i.r. and electronic spectroscopy. A number of Cu'' complexes with NH,, H20, and NO, were detected, and ammonium naphthenates and naphthenic acids were also found in the mixtures.54 have determined the kinetics of the reaction (2) in liquid ammonia solution. The reaction is first-order in [NH:] and [BH,]. Briggs and NH,Br +NaBH, + NaBr + H, +BH,,NH, Hydroxylamine. Studies of complexes of hydroxylamine with d-electron (mainly 3d) elements have been reported by two groups of workers. Hughes and Shrimanker'" have prepared and characterized a number of Ni", Zn", Cd", and Co'' species containing hydroxylamine as ligand. All the nickel compounds are six-co-ordinate; the ligand is N-bonded to the metal and is present as NH20H. 1.r. spectroscopy indicates that the product from Ni(OH), and NH30H' C1- probably incorporates hydroxylamine as the N-oxide isomer ONH3, as do the complexes [Cd(ONH3),X2] (X = C1or Br) and [Co(ONH3),X2] (X = C1or $0,). Iva~hkovich~' has determined (pH-metrically) stepwise and overall instability constants and co-ordination numbers at 20 "C and unit ionic strength (using KCl) of complexes of Cr"', Mn", Fe", Co", Ni", Cu", Cu', and Zn" with hydroxyl- arnine. The reaction of metal salts with alcoholic solutions of NH,OH' C1- is claimed to be a new method employed in the preparation of hydroxylamine complexes of Mn", Co", Co''', Ni", Cu", and Zn". Manganese(r1) is said to bond to 0, and Co", Ni", and ZnII to N, in these species. Bonds to Nitrogen.-The N2H2 Molecule. Three possible configurational isomers can be envisaged for diazene (di-imine), viz. trans-diazene (l), cis-diazene ( 2) , and isodiazene (3). Two methods have hitherto been available for the preparation (2'1 H \ / H ' LN H H N=N / / H /N=N H (1) (2) (3) of gaseous diazene; microwave radiolysis of hydrazine, and thermolysis of alkali- metal tosylhydrazides (Scheme 1). 1.r. data show the N2H2 arising from lithium tosylhydrazide, and examined in the solid state at -196"C, to be trans-diazene. H " -.-rowave Tos H iolwis thermolvsis \ / Scheme 1 L, N. Semenova and E. L. Abramovd, Uzbek. khim. Zhur., 1975, 19, 60. T. S. Briggs and W. L. Jolly, Inorg. Chem., 1975, 14, 2267. M. N. Hughes and K. Shrimanker, Inorg. Chim. Acta, 1976, 18, 69. E. M. Ivashkovich, Tezisy Dok1.-Vses. Chugaevskoe Soveshch. Khim. Kompleksn. Soedin., 12th, 1975, 3, 390 (Chem. Abs., 1976, 85, 167466). 54 55 56 57 180 Inorganic Chemistry of the Main - Group Elements However, it has now been reported5' that the N2H2 produced in the same way from caesium tosylhydrazide differs in its physical and chemical properties from trans-diazene, thus indicating the formation of isomer (2) or (3). Moreover, the N2H2 produced, together with much ammonia, by microwave radiolysis of hyd- razine corresponds in its properties to the thermolysis product of caesium tosyl- hydrazide. The authors report that the instability of 'isomeric diazene' has so far precluded the recording of its low-temperature i.r. spectrum, and its structure is uncertain, but, on the basis of other evidence ( e. g. mass spectrometry, which indicates the energy content of 'isomeric diazene' to be some 54 kJ mol-1 greater than that of trans-diazene), they tentatively prefer the isodiazene (3) over the cis-diazene structure (2) for the new isomer. Hydrazine. During the year under review, a study of the formation of hydrazine on zeolites under irradiation has been rep~rted,'~ but interest in the inorganic chemistry of hydrazine has centred principally on its reactions with metal com- pounds, yielding complexes. Also, with the exception of the synthesis4' of [Mo(CO),(N,H,)] from Mo(CO)~ and N2H4, this topic has mainly attracted the attention of Russian workers; e.g., Sakk6' has investigated the MC12-N2H2 binary systems (M = Mg, Ca, Sr, or Ba) thermogravimetrically and has isolated the crystalline compounds MC12,2N2H4 (M = Mg, Sr, or Ba) and CaC1,,N,H4. The thermal stability of the bis-adducts increases in the order Ba < Sr C Mg, and i.r. data provide evidence for co-ordinated N2H4 in all four complexes. Co,(P04),,8H20 reacts with N2H4,H20 to give Co3(P04),,6N2H4,6H20, the thermal decomposition of which was also studied." Ti2(C204),, 10H20 (prepared by addition of aqueous TiCl, and EtOH to H2C204 solution in an inert atmos- phere) reacts with N2H4 in EtOH to give Ti20(C204)3,5N2H4,2H20. TiC1, in solution reacts directly with aqueous (N2H4)2,H2C204, yielding Ti2(C204),,N2H4,- H2C2C4,6H20. The magnetic susceptibility (at 85-293 K), effective magnetic moment, and thermal decomposition of the latter have been reported.62 Aliev and co-workers have obtained hydrazine complexes from reactions of a number of yttrium(m), lanthanum(m), and lanthanide(m) salts with hydrazine hydrate or hydrazinium Azides. Dropwise addition of a concentrated solution of iodine in CH2C12 to AgN3 in the same solvent, with stirring at O'C, followed by evaporation, gives yellow, crystalline IN3. This product was characterized by its i.r. spectrum, which was interpreted in terms of C, symmetry.66 PCl, reacts with excess NaN, to form Na[P(N,),] rather than P(N3)5, as reported previously (W. Buder and A. Schmidt, 2. unorg. Chem., 1975, 415, 263). Na[P(N3)6] reacts with R4NN3 (R = Me or Et) The species obtained are listed in Table 2. N. Wiberg, G. Fischer, and 13. Bachhuber, Angew. Chem. Internut. Edn., 1976, 15, 385. T. G. Lyapina, E. A. Borisov, and A. G. Kotov, V. Sb., 1-ya Vses. Konf. Primenenie Tseolitov u Kutulize, 1976, 23 (Chem. Abs., 1976, 85, 182 841). Zh. G. Sakk, Russ. J. Inorg. Chem., 1975, 20, 849. M. G. Lyapilina, E. I. Krylov, E. A. Nikonenko, and V. A. Sharov, Russ. J. Inorg. Chem., 1975, 20, 1186. M. G. Lyapilina, E. I. Krylov, and V. A. Sharov, Russ. J. Inorg. Chem., 1975, 20, 1263. 58 5 9 60 61 62 63 R. Ya. Aliev and D. B. Musaev, Doklady Akad. Nauk Azerb. S.S.R., 1975, 31, 27. 64 R. Ya. Aliev and D. B. Musaev, Zhur. obshchei Khim., 1976, 46, 9. 65 R. Ya. Aliev, Uch. Zap.-Minist. Vyssh. Sredn. Spets. Obrur. Az . S.S.R., Ser. khim. Nuuk, 1975, 77 " K. Dehnicke, Angew. Chem. Internut Edn., 1976, 15, 553. (Chem. Abs., 1976, 85, 136 413). to give R4N[P(N3)6]. The [P(N3)6]- anion, which is very explosive, was charac- terized by vibrational The thermal decomposition of single-crystal and powder samples of KN,, in an ultra-high-vacuum environment, has been studied. Mass spectrographic detection was used to monitor the decomposition products, and, from the temperature dependence of the partial pressure of nitrogen, three decomposition regions were found. Azide radicals and potassium atoms were also detected. The application of an electric field across the sample during decomposition was investigated, and models for the decomposition process were discussed.68 Bonds to Oxygen.-General. A study of the oxidation of NO by dilute HN03, including the mathematical modelling of the reaction, using a computer, has been Schultheiss and Fluck have investigated the reactions of cis- and trans-Na2N202 and a -Na2N,03 with N204, using X-ray photoelectron spectroscopy. The pro- ducts were found to be NO,, together with some starting material and NO,, identified by their nitrogen 1s binding energies. The results were confirmed by correlations of binding energies with atomic charges obtained by CNDO/INDO M.O. cal c~l ati ons.~~ Nitrogen(1) Species. Na2N202 reacts with the complex [CoCl(NO),(Ph,P)] to give the binuclear species [CO(NO), CP~, P)]~(~-N~O~), in which the CO‘ moieties are linked by a bridging dioxodinitrate(1) ligand.71 Nitric Oxide. Nitrogen(I1) oxide reacts with the complex [Co(NO) (Ph3P)3] in benzene or toluene solution to give [Co(NO),(ONO)(Ph,P)], Ph3P0, N2, and N20. The same reaction, carried out with a molar ratio 1 : 2 (Co complex :NO), gives the trinuclear complex [Co,(NO),(Ph,P),], which is capable of catalysing the disproportionation of NO.71 The catalysed ,eduction of NO, from effluent gas P. Volgnandt and A. Schmidt, Z. anorg. Chem., 1976, 425, 189. 67 68 A. De Panafieu, B. S. H. Royce, and T. Russell, J. Chem. Phys., 1976, 64, 1473. 69 V. V. Zubov, G. A. Zhodzishskii, L. Ya. Tereshchenko, V. P. Panov, and V. M. Nikolaev, V. sb., 70 H. Schultheiss and E. Fluck, J. Inorg. Nuclear Chem., 1975, 37, 2109. Tekhnol. Neorgan. Veshchestv., 1975, 33 (Chem. Abs., 1976, 85, 13 236). M. Gargano, P. Giannoccaro, M. Rossi, A. Sacco, and G. Vasapollo, Gazzetta., 1975, 105, 1279. 71 182 Inorganic Chemistry of the Main - Group Elements streams with ammonia has considerable technological importance, and the [CO"'(NH,),,(NO)]~' complex within a Y-type zeolite is found to be a catalyst for the reaction of NO with NH3, giving N2 and H,O at temperatures greater than 50 "C. The presence of [CO"'(NH,),(NO)]~' in a zeolite facilitates the intra- molecular reaction between the nitrosyl and ammonia ligands, as well as the disproportionation of NO. The latter reaction, however, results in the formation of N20 and [Co"'(NH,), (NO,)]", which terminates the catalytic activity of the cobalt-ammine complex. However, the disproportionation reaction is negligible provided that the partial pressure of NO in the gas phase is less than 1 T ~r r . ~~ The reaction of NO with 0,' SbF; has been reported by Russian7, and American7, workers to give NO' SbF,, together with NO;, or NO; SbF,.74 The work at the Argonne National L ab~ratory, ~~ which involved NO and NOz (see below), formed part of a study of reactions of 0,' SbF, in liquid water, water vapour, and gases that occur as contaminants of the air in mines. The Russian group', also investigated the reaction of NO with the compound XeF' SbF,, which can be represented by equation (3). XeF'SbF; +2 N0 + NO'SbF; +Xe +NOF (3) In the thermal and photochemical reactions of Me3SiC1 with NO, and in the photochemical reaction of C1,SiH with NO, Si-Cl bond cleavage was preferred, and the primary reaction was abstraction of C1. SiH, did not react with NO. During the dark reaction with Me,SiCl, the products were NOCl, N20, (Me,Si),O, and siloxane The positive ions and neutral species pro- duced in glow discharges of gas streams containing 1.0% NO in He, 29% dry air in He, and 1.06% NO in N2 have been studied by mass spectrographic measure- ments. NO', Nl , Oi, N', and 0' were observed, with lesser amounts of He', He,', and NO;. Variations in the amounts of ionic and neutral species with discharge duration were consistent with an electrically induced dissociation of NO to produce N and 0. No nitrogen oxides were formed in glow discharges of the He-air mixtures.76 Some details of an i.r. spectroscopic study of reactions of NO with SnCl, and PbF, in argon matrices have already been outlined above.3 Nitrogen(II1) Species. The reaction of the nitrosonium salt NO' BF; with the dioxygen complex [Pt(PPh3)202] in acetonitrile solution produces [Pt(PPh,),NO,]+ BF,, which probably incorporates a symmetrically bidentate nitrato-ligand, I n less basic and more poorly co-ordinating solvents, e. g. MeNO,, containing traces of water, the primary product (more than 50%) formed in the reaction of [M(PPh3)202] and NO' X- (M=Pt or Pd; X=BF, or PF,) is the hydroxy-bridged dimer [M,(PPh,),(OH),]X,, while the nitrato-complex [M(PPh,),(NO,),] is formed in variable yields. Reactions of NO' salts with some other Pto complexes have also been found to give cationic Pt" species.77 72 K. A. Windhorst and J. H. Lunsford, J.C.S. Chem. Comm., 1975, 852. A. A. Arlyukhov, V. A. Legasov, and B. B. Chaivanov, Atomnaya Energiya., 1975, 39, 222. L. Stein and F. A. Hohorst, J. Znorg. Nuclear Chem.- Herbert H. Hyman Memorial Volume., 1976, 73. R. Varma, P. Orlander, and A. K. Ray, J. lnorg. Nuclear Chem., 1975, 37, 1797. D. G. Keuhn, E. S. Khalafalla, and L. M. Chanin, US. Bureau of Mines, Report Znuesr., 1975, RI8063. 73 74 75 76 77 D. A. Phillips, M. Kubota, and J. Thomas, Znorg. Chem., 1976, 15, 118. Elements of Group V 183 Figure 2 The crystal structure of Na,NO,. The NO; group is shown in one of the possible (Reproduced by permission from Angew. Chem. Internat. Edn., 1976, 15, 377) orientations A handful of papers dealing with nitrites has been published. Na3N03 was obtained as a golden-yellow, microcrystalline, moisture-sensitive powder by heat- ing an equimolar mixture of Na20 and NaN02 in a closed Ag crucible (310 "C, for 3 days). The crystal structure of Na,N03 (Figure 2) has been shown to contain the NO, ion and no NO:- groups. It is not, therefore, an 'orthonitrite', and is formulated as (N02)0Na,, of anti-perovskite type.78 The decomposition of NaNO, follows first-order kinetics, its character depending upon temperature. Oxygen and a pH < 5 accelerate the decomp~sition.'~ The thermal decomposition in air of KN0,-Cr203 mixtures of different molar ratios n : 1 (n = 0.5, 1-6, 8, or 10) has been studied by thermogravimetry and d.t.a. Cr203 is found to lower the decomposition temperature of pure KNO,. When mixtures with n 5 6 are heated to 700°C for 15 min, all of the CrI'I is oxidized to K,Cr04.80 The thermal characteristics, as revealed by differential heating curves, of the double nitrites (N02)3],H20, and Ba[Ag(NO,),] have also been determined.8' NO,-N204. Both of the reaction studies on 0; SbF, already in connection with NO also included the reaction with NOz, which proceeds accord- ing to reaction (4). In addition, the Russian group73 have reported that the 2[KAg(N02)2I,H20, Cs[Ag(NO2)2I, K2[Ba(NO,)41, K,[Cu(NO2),I, WA g- O,*SbF, +NO, + N0;SbF; + 0, (4) reactions of the compounds XeF+SbF, and KrF' Sb2FY1 with NO2 also yield NO,' SbF,, together with the other products shown in reactions (5) and (6). 2XeF+ SbF; +2N02 + 2NOl SbF; + Xe +XeF, KrF+Sb2F;, +2N0, + 2NOlSbF; +Kr ( 5 ) (6) N204 reacts with ClOS0,F at 20 "C to give NO,' OS02F- and C1N0,.82 78 M. Jansen, Angew. Chem. Internat. Edn., 1976, 15, 376. J. Knapczyk, Acta Polon. Pharm., 1975, 32, 683. M. R. Udupa, Thermochim. Acra, 1976, 17, 266. L. V. Soboleva, M. G. Vasil'eva, and V. V. Ogadzhanova, Russ. J, Inorg. Chem., 1975, 20, 1501. A. V. Fokin, A. D. Nikolaeva, Yu. N. Studnev, A. I. Rapkin, N. A. Proshin, and L. D. Kunetsova, Izvest. Akad. Nauk S.S.S.R., Ser. khim., 1975, 1000. 79 81 82 184 Inorganic Chemistry of the Main- Group Elements Nitric Acid. 180-Multilabelled anhydrous HNO, (89 atom.% l80) has been prepared by the exchange reaction of HN03 with H2I 80, neutralization with NH3, distilling off the exchanged H20, dissolving the labelled NH,NO, in the strong acid MeSO,H, and distillation of labelled anhydrous HN03. The use of F3CS03H, H2S04, and oleum in the final stage was also investigated, but these acids were found to be unsuitable because there was rapid exchange of oxygen.', A group of French workers has studied the interaction of nitric acid with nitromethane', and with NN-dimethylformamide (DMF)85 by the determination of liquid-solid equilibria and by vibrational spectroscopy. The phase diagram of the system HN0,-MeNO, reveals the existence of a 1 : 1 compound, shown by vibrational spectroscopy to be a weakly hydrogen-bonded complex which also exists in solution, e.g. in CCl,.*, I n the HN0,-DMF system, 1: 1 and 2: 1 adducts are formed. The spectroscopic studies indicate that the 2 : 1 compound consists of DMF,H' that is strongly hydrogen-bonded to NO,,HNO,, in which HNO, is only weakly hydrogen-bonded to NO;. The 1 : 1 complex consists of the ions DMF,H' and NO;, which interact by very strong hydrogen-bonding.85 Following earlier studies of molal freezing-point depression in eutectic aqueous perchloric acid (M. Ardon and L, Halicz, Inorg. Chem., 1973, 12, 1903), similar investigations in eutectic aqueous trifluoroacetic acid86 now show that nitric acid dimerizes in both of these media. In the light of these results, dimerization in aqueous solutions of nitric acid itself, in concentrations of ca. 5 moll-', is considered to be a distinct possibility, but no information on the structure and bonding of the dimer is yet available. Nitrates. The product of the reaction of stoicheiometric amounts of aqueous Ba(NO,), and CuSO,, after removal of BaSO, and suitable treatment of the resulting solution to prevent hydrolysis to a mixture of basic copper(I1) nitrite and nitrate, was not Cu(NOZ), but the new compound CU(NO)(NO,).~~ The use of a new zone-refining apparatus has been investigated for the removal of 3d transition-metal impurities, especially chromium, from alkali-metal nitrates, which are now essential raw materials of multicomponent glasses used for optical communications. Chromate is formed from Cr in fused alkali-metal nitrates and is dissolved abundantly into them. The effect of various essential factors, such as the rate of travel of the melted zone, on the effective distribution coefficient (k) of Cr was discussed; under optimum conditions, the k values in the NaN0,-Na,CrO, and KN0,-K2Cr0, systems indicated the usefulness of the technique for the purification of some inorganic salts with relatively low melting points.88 83 A. C. Scott, J. H. McReynolds, and M. Anbar, J. Labelled Compounds, Radiopharm., 1976,12,63. 84 L. Diop, C. Belin, and J. Potier, J. Chim. phys., 1976, 73, 201. 85 L. Diop, C. Belin, and J. Potier, J. Chim. phys., 1976, 73, 207. 86 M. Ardon and G. Yahav, Inorg. Chem., 1976, 15, 12. " P. Tarte and M. Liegeois-Duyckaerts, Compt. rend., 1976, 282, C, 699. 89 G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1975, 20, 856. Y. Hoshino, T. Utsunomiya, and T. Yasukawa, Nippon Kq a k u Kaishi, 1976, 901. N. V. Krivtsov, G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1975, 20, 1868. N. V. Krivtsov, G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1976, 21, 1409. G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1976, 21, 799. 88 90 91 G. N. Shirokova, S. Ya. Zhuk, and V. Ya. Rosolovskii, Russ. J. Inorg. Chem., 1976, 21, 527. 92 93 Elements of Group V 185 Rosolovskii and co-workers have reported extensions of their studies on aluminium nitrate systems in five publication^.^^-^^ Rb[Al(NO,),] has been prepared by the reaction of Rb[A1Cl4] with an excess of N205 in HNO, solution, and the reaction of AlBr, with a solution of RbN0, and N205 in HNO, was used to make Rb2[Al(N03)5]. The new complexes were investigated by derivatography, i.r. spectroscopy, and X-ray powder diffra~tion.'~ The isolation of Rb2[Al(N03)5] permitted the determination of its enthalpy of dissolution iri water at 25 "C, from which its enthalpy of formation was cal ~ul ated.~~ The reaction of AlBr, and K[AlCl,] with KNO, and N205 in a medium of 'nitric oleum' (a solution of N205 in anhydrous HNO,) was also studied. K2[A1(N03)5] or K,[Al(NO,),] is formed, depending on the ratio of the starting materials, but K[Al(NO,),] does not crystallize in this system. The penta- and hexa-nitrato-aluminates of potassium were examined by the techniques men- tioned above for the rubidium nitrato-aluminates. The compound K3[A1(NO3),] is the first example of a salt containing the [Al(N0,),]3- anion, the i.r. spectrum of which is consistent with the presence of six unidentate nitrate ligands. The authors also conclude that the thermal stability of the nitrato-aluminates is lower the greater the number of bidentate nitrato-groups in the anion (pentanitrato- aluminate contains one such group and tetranitrato-aluminate is likely to incorpo- rate Again, the enthalpies of dissolution in water of K2[Al(N03)5] and K3[A1(NO3),] were measured, and their standard enthalpies of formation calcu- lated.92 Success has also been achieved in the preparation of pure anhydrous Al(N03)3, in good yield, from the reaction (7) and vacuum sublimation at 50°C. The solubility, thermal decomposition, and i.r. spectrum of the previously elusive and highly volatile trinitrate are described and discussed. I t was concluded that the bonding of the (presumably) bidentate nitrate groups to the central metal atom has a high degree of covalency.93 The work on potassium and rubidium tetranitratogallates(n1) reported last year by another Russian group (see Volume 4 of this series of Specialist Periodical Reports) has also been extended. The same authors have now synthesized the new anhydrous gallium nitrato-compounds Ga(NO,),, Li[Ga(N03)4], and Na[Ga(NO,),] by reactions of N205 with GaBr, or equimolar mixtures of GaBr, and LiBr or NaBr. Ga(NO,), sublimes at 140°C in an atmosphere of argon.94 At 200-700 "C, NaNO, is reduced by H2 to give NaOH, N2, and H20; NaNO, is an intermediate, whereas at < 100 "C NaOH, H20, and NH3 are the thermo- dynamically more favoured Unipositive cation nitrates MNO, (M = K, Rb, Cs, Me,N, Et4N, or Bu,N) react slowly with BCl, in CHC1, at 20°C in vacuum to give M[C1,BN03] and M[B(ONO,),]. The solid reaction products also contain M[BCl,], and it is considered that the reactions occur in two stages, with the initial formation of M[Cl,BNO,], which disproportionates to M[BC14] and M[B(ON0,)4].96 3NO2[A1(N0,),] + AlCl, + 4A1(N03), +3N02C1 (7) B. N. Ivanov-Emin, Z. K. Odinets, S. F. Yushchenko, B. E. Zaitsev, and A. I. Ezhov, Russ. J. Inorg. Chem., 1975, 20, 843. 94 95 N. P. Kurin and N. F. Stas, Izvest. Vyssh. Uchebn. Zaued., Khim. i khim. Tekhnol., 1976,19, 810. 96 K. V. Titova and V. Ya. Rosolovskii, Izvest. Akad. Nauk S.S.S.R., Ser. khim., 1975, 2359. '' M. N. Nabiev, I. A. Borukhov, and 0. A. Momot, Russ. J. Inorg. Chem., 1976, 21, 1076. 186 Inorganic Chemistry of the Main - Group Elements Debyeograms and thermograms of melts of Mg(N03),,6H20 and MeCONH, i ndi ~ate’ ~ the formation of the adduct Mg(NO3),,4MeCONH,,H2O. The composition of sparingly soluble products of the reaction of Pb(N03)~ (and PbC12) with H3PO4 in aqueous solutions has been investigated by the method of residual concentrations, and by measurement of refractive indices, densities, and pH of the liquid phases and the chemical analyses of precipitates.’* The precipi- tate Pb2(N03)(P04) is formed in accordance with reaction (8) when [H3P04] 25 mol% , but a solid phase of variable composition results when [H3P04] 3 30 mol% . 2Pb(N03), +H3P04 + Pb2(N03)(P04) +3HN03 (8) The reactions of K2TiF6, Ti02, TiC14, and TiC13 have been ~tudi ed’ ~ in pure molten LiN03-KN03 eutectic and in basic nitrate melt solutions containing Na,O,, Na,O, or NaOH. TiO, as anatase and titanates of varying basicity were produced, depending on the concentrations of base and the temperature. When chloride was present, (NO),[TiCl,] sublimed from the melts at < 200 “C. Reac- tions of the representative range of 3d-metal sulphides TiS,, VS, Cr2S3, MnS, FeS, CoS, NiS, CuS, and ZnS with molten KNO, have also been studied. In the melt, Ti, Ni, Cu, and Zn metal cations exhibited acid-base reactions and were precipitated as metal oxides, whereas V, Cr, Mn, Fey and Co metal cations showed oxidation-reduction as well as acid-base reactions, and were converted into VO,, Cr0:-, MnO,, Fe203, and c0304, respectively. In all cases, S2- was oxidized to SO:-, and the nitrate melt was reduced to nitrite and oxides of nitrogen. The stoicheiometries of the reactions were established.100 The dependence of the dehydration temperature on pressure has been observed for the loss of two molecules of H20 during dehydration of Ca(N03),,4H20. The remaining two H20 molecules are bound much more strongly, and the tempera- ture at which these molecules are lost does not depend on pressure. The enthalpy, entropy, and thermodynamic potential for the loss of two molecules of H,O from Ca(N03),,4H,0 have been quoted.lol A number of studies of the thermal decomposition of nitrates, involving the use of thermogravimetry, d.t.a., chemical analyses, i.r. spectroscopy, and X-ray powder diffraction, have been carried O U ~ . ~ ~ ~ - ~ ~ ~ The thermal decomposition of intimate mixtures of different molar ratios of KN03 and Cr203 shows that KNO,, in the presence of Cr203, starts to decompose at ca. 350 “C, which is much below the decomposition temperature of pure KN03. Furthermore, Cr”’ is completely oxidized to Crvl when the mole ratio of KN03 to Cr,O, is greater than 3.l” The thermal decomposition of Y(N03)3,5H20 yields Y(N03),,3H,0, Y(N03)3,H20, Y(NO3)3, and YON03, successively.103 The anhydrous nitrate can be prepared by isothermal heating at 160 and 180”C, but it decomposes at 200°C. The further I E. A. Gyunner, I. S. Vel’mozhnyi, and L. M. Mel’nichenko, Russ. J. Inorg. Chem., 1976,21, 1059. 98 99 D. H. Kerridge and R. J. Cancela, J. Inorg. Nuclear Chem., 1975, 37, 2257. loo B. J. Meehan and S. A. Tariq, Austral. J. Chem., 1975, 28, 2073. lo’ 0. A. Momot and M. T. Saibova, Uzbek. khim. Zhur., 1976, 11. lo2 M. R. Udupa, Thermochim. A m , 1976, 16, 231. G. Odent and M. H, Autrusseau-Duperray, Rev. Chim. mindrale, 1976, 13, 196. B. N. Ivanov-Emin, Z. K. Odinets, Kh. Del’Pino, B. E. Zaitsev, and A. I. Ezhov, Izuest. Vyssh. Uchebn. Zaved., Khim. i khim. Tekhnol., 1976, 19, 851. B. N. Ivanov-Emin, Z. K. Odinets, Kh. Del’Pino, and B. E. Zaitsev, Russ. J. Inorg. Chem., 1976,21, 456. 103 104 105 Elements of Group V 187 thermolysis of YONO, does not lead to an oxide but rather to a phase of variable composition, whose structure is derived from that of Y,O,. In contrast, the thermal decomposition of the related heavier lanthanide(II1) nitrate tetrahydrates of Ho, Er,lo4 Tm, and Yb105 does not yield the corresponding anhydrous nitrates, but gives the metal(II1) oxides as the final products. NO,' Salts. Monoclinic NO; Se0,F- has been prepared by the reaction of SeO,F, with anhydrous HNO, and characterized by vibrational spectroscopy and X-ray powder diffraction.lo6 Bonds to Fluorine.-Christe and his group have reported the synthesis, and characterization by 'H and 19F n.m.r. and vibrational spectroscopy, of the first known examples of NH2Fz also the application of low-temperature U.V. photolysis to the synthesis of novel (and to the improved synthesis of known) NF,' salts.108 The difluoroammonium salts NH2Fi SbF, and NH2Fi AsF, were ob- tained as white crystalline solids by protonation of difluoramine in HF-MF, (M= As or Sb) solutions according to reaction (9). They are stable at -50 "C, but NHF, + HF +MF, -+NH,FZ +MF; (9) tend to undergo spontaneous exothermic decomposition at room temperature, with elimination of HF. Attempts to prepare either NHF; salts (presently un- known) by protonation of NF3 at temperatures as low as -78"C, or fluorine- substituted ammonium salts by direct fluorination of NH; AsF, in HF solution in the temperature range -78 to +25 "C, were ~nsuccessf ~l . ~~~ Low-temperature U.V. photolysis was used to synthesize the novel salts NF; PF, and NF; GeF, and the known salts NFf BFT and NF; AsF,. The photolysis for one hour at -196 "C of a mixture of NF,, BF3, and F, is typical of the technique which, in this case, offeis the first convenient, simple, and high-yield synthesis for pure NF: BF,. The NF; salts were characterized by vibrational and 19F n.m.r. spectroscopy and X-ray powder data, and some of their reactions were investigated. The applicability of low-temperature U.V. photolysis to other reactant systems was also briefly studied. lo' Reactions of NOF and N02F with PtF,, 0; PtF,, PtF,, IrF6, NO' PtF,, NO,' PtF,, NO' IrFi, and NO,' IrF; have been examined under a variety of conditions. The NO; ion is found to be intrinsically unstable with respect to the elimination of oxygen in Pt'" and IrrV fluorometallate salts. Raman spectral data for NO' BK , NO,' BFZ, NO,' AsFi, NO' PtF;, NO,' PtFi, (NO'), PtF;-, NO' IrF;, NO,' IrFi, and (NO'), 1rF;- are presented and analysed.log Bonds to Bromine and Iodine.-Pure NBr, is precipitated as a deep red solid when the reaction (10) is conducted in n-pentane at -87°C. The compound is (Me,Si),NBr + 2BrCl + NBr, +2Me3SiC1 (10) thermally unstable, and a suspension in Nujol explodes even at -100°C when disturbed by the slightest mechanical shock. It is soluble without decomposition in polar solvents that are not susceptible to bromination or oxidation. NBr, reacts M. Cernik and K. Dostal, Z. anorg. Chem., 1976, 425, 37. K. 0. Christe, Inorg. Chem., 1975, 14, 2821. K. 0. Christe, C. J. Schack, and R. D. Wilson, Inorg. Chem., 1976, 15, 1275. J. E. Griffiths and W. A. Sunder, J. Fluorine Chem., 1975, 6, 533. 108 188 Inorganic Chemistry of the Main -Group Elements instantaneously with ammonia to give violet-black monobromamine, as shown in reaction (1 1). With tertiary organic N-bases, molecular addition compounds with bromine are formed, and iodine reacts with a solution of NBr, in CH2C12, yielding solid, red-brown nitrogen dibromide monoiodide [reaction (12)], which shows higher thermal stability than nitrogen tribromide.' lo NBr, +2NH3 + 3H,NBr (1 1) NBr, +I, -+NBr,I +1Br (12) 2 Phosphorus Phosphides.-The structural chemistry of metal phosphides obtained by high- temperature reactions with phosphorus has been further elucidated by the publi- cation this year of the results obtained from studies of single crystals of MgP4,ll1 LaP5,112 NdP5,"* and GdP5.113 The magnesium compound is an isotype of CdP4, with phosphorus atoms tetrahedrally connected to either two magnesium and two phosphorus atoms or one magnesium and three phosphorus atoms. The lanth- anum pentaphosphide is a superstructure variant of NdP5, while the latter is isotypic with GdP5. In all the compounds the P-P distances fall in the range 2.16-2.22 A. Preliminary X-ray data are available for BeP,, the black, stable product obtained by heating beryllium-phosphorus mixtures progressively to 1000 "C;l14 refinement of the VP, structure indicates an NbAs, ~tr uct~r e, ' ~~ while in the ternary MP-MOP and MP-WP systems, products such as M0.5M00.5P and Mo.5Wo.sP for M= Co or Ni are formed.ll6 Bromine analogues M,PBr (M=Ca, Sr, or Ba) of the chlorides reported last year have been prepared and chara~teri zed.~~~ The cubic phases for Ca,PBr and Sr,PBr are stabilized by an excess of the metal dibromide, while the correspond- ing rhombohedra1 phases are stabilized by an excess of the phosphide M3P2. Two new silyl phosphanes, (Me,Si),P, and (Me3Si)4P14, can be isolated from the products of the reaction between white phosphorus and trimethylchlorosilane in the presence of Na-K alloy at ca. 80°C.1'8 The P, species forms colourless crystals that are readily decomposed by oxygen but stable to ca. 300°C in the absence of air; the P14 compound is isolated as a yellow powder which decom- poses at ca. 210°C. Compounds containing P-P Bonds.-Diphosphorus tetraiodide reacts with NaCr(CO)5 in benzene to give a diamagnetic, monomeric complex (4) containing a co-ordinated P213 group.''' The phosphorus environments are shown to be different, from 31P n.m.r. data, but exchange of iodine between the two phosphorus atoms leads to a temperature-dependent equilibrium. Triphenyl- and tricyclohexyl-phosphines react with (4) to give compounds with the stoicheiometry (OC),CrPI,,PR,, which are probably dimers. J. Jander, J. Knackmuss, and K.-U. Thiedemann, Z. Naturforsch., 1975, 30b, 464. H. G. von Schnering and G. Menge, Z. anorg. Chem., 1976, 422, 219. '12 W. Wichelhaus and H. G. von Schnering, Z. anorg. Chem., 1976, 419, 77. G. Menge and H. G. von Schnering, 2. anorg. Chem., 1976, 422, 226. '14 J. David and J. Lang, Compt. rend., 1976, 282, C, 43. 11' M. Golin, B. Carlsson, and S. Rundqvist, Acta Chem. Scand. (A), 1975, 29, 706. '16 R. Gutrin and M. Sergent, Compt. rend., 1975, 281, C, 777. 11' C. Hadenfeld and W. Kosiol, Z. Naturforsch., 1975, 30b, 378. '19 G. Schmid and H.-P. Kempny, Z. anorg. Chem., 1975, 418, 243. 110 111 113 G. Fritz and W. Holderich, Naturwiss., 1975, 62, 573. Elements of Group V 189 'I (4) H3B-P,- P-BH, OM/ ' bMeOMe ( 5) A new type of diphosphane derivative ( 5) has been obtained recently during the reduction of the borane adduct (Me0),P,BH3 with sodium naphthalide in 1,2- dimethoxyethane.12' The product isolated as the sodium salt is thermally and hydrolytically stable, and, although the n.m.r. data are not wholly definitive, the trigonal-bipyramidal structure with an axial P-P bond ( 5) has been suggested. Recent 31P n.m.r. measurements point to the presence of an open-chain anion in the salts M2(PPh)3 (M = Na or K),12' contrary to previous suggestions, but the data show better correlation with those for the linear phosphine HPhPPPhPPhH than those for triphenyl-cyclotriphosphane. 31P n.m.r. data have also been used1,, to assign the triphosphane structure R1P[P(0)(OR2),], to the products from reactions between aryl dichlorophosphines and sodium dialkyl phosphites, in contrast to the triphosphite structures R1P[OP(OR2),I2 suggested earlier. Tris(diethylphosphoryl)phosphine, P[P(O)(OEt),],, reacts with secondary amines (R2NH),12, eliminating one diethylphosphoryl group as the amine deriva- tive R,NP(O)(OEt), and producing the substituted ammonium salt of bis(die thylphosphory1)phosphinidine (6). Tris(die thylphosphory1)phosp hine is also the starting material for the preparation of the novel triphosphanes R3P= P-P(O)(OEt),, which contains both a P==P double bond and a two-co-ordinate phosphorus(rr1) atom.124 The other reactants are trialkylphosphines, and the products arise by elimination of (EtO),PP(O)(OEt),. H H' \fi / R/ \R (6) Problems of ring size in cyclopolyphosphine chemistry have been attacked again by a 31P n.m.r. method that involves decoupling all other magnetic n~c1ei .l ~~ The observed shift indicates the ring size, and depends linearly on the mean endocyclic 120 L. A. Peacock and R. A. Geanangel, Inorg. Chem., 1976, 15, 244. 12' M. Baudler, D. Koch, E. Tolls, K. M. Diedrich, and B. Kloth, Z. anorg. Chem., 1976, 420, 146. 12? K. M. Abraham and J. R. van Wazer, lnorg. Chem., 1976, 15, 2322. lZ3 D. Weber, G. Heckmann, and E. Fluck, 2. Naturforsch., 1976, Slb, 81; D. Weber and E. Fluck, 124 D. Weber and E. Fluck, 2. anorg. Chem., 1976, 424, 103. 12' L. R. Smith and J. L. Mills, J. Amer. Chem. SOC., 1976, 98, 3852. lnorg. Nuclear Chem. Letters, 1976, 12, 515. 190 Inorganic Chemistry of the Main- Group Elements P-P-P bond angle. Cyclotetraphosphines give a single line, whereas P3 and P, systems give, respectively, second-order ABB' and ABB'CC' systems. The atoms in the latter are not equivalent, as found for the P, system, as it is not possible to arrange a symmetrical trans alternation of the lone pairs on phosphorus atoms. The data can be used to assign pentaphosphine structures, i.e. (EtP)S, (Pr"P)S, and (BuP),, to compounds that were previously said to be tetramers. Weak signals in the 31P n.m.r. spectra of either melts or solutions of (PhP), have previously been assigned to the unknown monomeric and dimeric 'phenyl phosphorus', but, by comparison with data from authentic samples, they are now known to be due to traces of (PhP)4 and (PhP)6.126 The cyclotetraphosphine can be obtained in high yield from a ring-closure reaction between Me,SiPhP*PPh.PPhSiMe, and PhPCl,, and a tetrameric structure has been assigned to both the ethyl derivative (EtP), and the mixed phenyl-ethyl compounds, because the chemical shifts of phos- phorus are similar to those of (PhP),. Some ambiguity thus still remains in this area. There is also ambiguity concerning the polyphosphorus species formed when (PhP), is treated with alkali metals in THF solution, but new 31P n.m.r. data are providing information showing complex dependence on both the metal and the temperature.',' With potassium, the product is K,(PhP),, but the data rule out a conventional straight-chain structure and suggest one containing a chelated potas- sium ion (7). While a similar structure appears to be probable for the disodium compound, the data for Li,(PhP), point to an acyclic structure. Similarly, linear structures now seem probable for the M2(PhP), species rather than the cyclic dianions considered previously. PhP-PPh [PIG'' ' K ' 'PPh] Bonds to Boron.-The behaviour of phosphine-borane, H3P,BH3, toward am- monia and methylamine or dimethylamine varies with temperature.128 At -45 "C the product with ammonia is the ionic solid [NH,][PH,(BH,),], but at higher temperatures the covalent ammonia-borane H3N,BH3 is also formed. With the two amines, the converse behaviour is observed, the covalent species MeH,N,BH, or Me,HN,BH, being produced at temperatures below -45 "C and increasing quantities of the ionic products [MeNH,][H,P(BH,),] or [Me2NH2][H2P(BH3),] occurring when the temperature is raised. Mechanistic models involving H,PBH; have been proposed for these processes. A staggered conformation is assumed for H3P,BF3, and values of 1.921 and 1.372A have been derived from microwave data for r(P-B) and r(B-F), re~pective1y.l~~ The barrier to internal rotation has been assessed as 3.39 f 0.4 kcal mol-'. N.m.r. data for further borane adducts of tertiary phosphines such M. Baudler, B. Carlsohn, W. Bohn, and G. Reuschenback, 2. Nuturforsch., 1976, 31b, 558. P. R. Hoffman and K. G. Caulton, J. Amer. Chem. SOC., 1975, 97, 6370. E. A. Dietz, K. W. Morse, and R. W. Parry, Znorg. Chem., 1976, 15, 1. J. D. Odom, V. F. Kalasinsky, and J. R. Durig, Znorg. Chem., 1975, 14, 2837. Elements of Group V 191 as R3P or RiR'P show that there is no simple correlation between their thermo- chemical stability and, for example, J(BP),13' but with analogous fluorophos- phine complexes, e.g. PF2X,BH3, the high basicity of the phosphine can be discussed in terms of electrostatic repulsions between the group X and the boron acid. 13' The P-B analogue of decalin (8) contains in its structure two cis-fused cyclohexane-type rings, in which the P-B distances imply that there is u-type interaction Bonds to Carbon.-Phosphorus(IrI) Compounds. A direct route to Me,PCl from methyl chloride and red phosphorus has been achieved by modification of the method used for preparation of MePC1, in which methyl chloride is passed over a mixture of phosphorus and copper powder packed in a glass The inclusion of active carbon in the last part of the tube is the important modification. Pyrolysis of MePCl,, CF3PH2, and Me,PH at 1000°C generates the unstable phospha-alkenes CH,=PCl, CF,=PH, and CH2=PH,134 and although these (2p-3p)v-bonded species are unstable, they can be identified by microwave spectroscopy. A preliminary value of 1.67 A has been obtained for the C=P bond length. Radicals containing a two-co-ordinate phosphorus or arsenic centre result from photolysis of the corresponding monochlorides in the presence of an electron-rich 01efin.l~~ E.s.r. measurements characterize the radicals, which have half-lives of the order of one month, as [(Me3Si)&H],M* and [(Me3Si),N]M- (M = P or As). E.s.r. data have also been used to identify the Me3PH radical as a product from y-irradiation of tri methyl ph~sphi ne.~~~ The tetrafluoroethylidene radical F(CF3)C* obtained by pyrolysis of C2F5SiF3 reacts with PF3 to give a mixture of CF,=CFPF, and PF,, and with (CF3)3P to give (CF3)2PCF(CF3)2.137 The I9F n.m.r. spectrum of the latter is complex, but first-order, with the signal due to the unique fluorine in the perfluoropropyl group giving rise to a 98-line multiplet, i.e. a doublet of septets of septets. The iodo-phosphine CF,P(H)I resulted from either equilibration of a CF3PH2-CF3P12 mixture or iodination of CF3PH2, and was converted into the corresponding chloride or bromide on treatment with the appropriate silver or mercury(I1) halide. 13* Mercury(I1) cyanide yielded the dicyanide CF,P(CN),, while reduction with metallic mercury gave the expected diphosphine CF3PHPHCF3. G. Jugie, C. Jouany, L. Elegant, J. F. Gal, and M. Azzaro, Bull. SOC. chim. France, 1976, 1. 130 131 L. F. Centofanti, J. Inorg. Nuclear Chem., 1976, 38, 265. 13' G. R. Clark and G. J. Palenik, Austral. J. Chem., 1975, 28, 1187. 133 F. W. Parrett and M. S. Sun, Synth. Inorg. Metal-Org. Chem., 1976, 6, 115. 134 M. J. Hopkinson, H. W. Kroto, J. F. Nixon, and N. P. C. Simmons, J.C.S. Chem. Comm., 1976,513. 13' M. J. S. Gynane, A. Hudson, M. F. Lappert, P. P. Power, and H. Goldwhite. J.C.S. Chem. Comm., 136 K. Nishikida and F. Williams, J. Amer. Chem. SOC., 1975, 97, 5462. 13' K. G. Sharp and I. Schwager, Inorg. Chem., 1976, 15, 1697. 13* R. C. Dobbie, P. D. Gosling, and B. P. Straughan, J.C.S. Dalton, 1975, 2368. 1976, 623. 192 Inorganic Chemistry of the Main-Group Elements Although the compounds have not been isolated, there is strong evidence from P n.m.r. spectrometry for the formation of the mixed cyano-halides P(CN),X3-,, where X = C1, Br, or I, and n = 1 or 2, in reactions between PX3 and silver cyanide in solution in 140dopropane.l~~ In addition, a number of ternary mixed cyano-halides were also detected. The mean P-CN bond dissociation energy has been assessed as 84 kcal mol-' from data on the heats of hydrolysis and formation of crystalline P( CN)3. 140 Microwave spectra for EtPH, and its deuteriation products suggest a 45 : 55 mixture of gauche- and trans-rotamers at room temperat~re.'~~ In the 1 : 2 adducts of trimethylphosphine with PX3 or AsX3 (X = C1or Br), i.r. and Raman spectra showed that trans configurations were adopted for all these monomeric complexes,142 but that with 1,2-bis(dimethylphosphino)ethane the complexes were forced into the cis configuration. On account of a possible explosion hazard, only small quantities of the propyne derivatives (CF3C%C)3M (M = P, As, or Sb) were synthesized from the required trihalide and LiCbCF3 in diethyl ether at -78°C.143 The bismuth analogue, on the other hand, could not be obtained in sufficiently large amounts to be able to purify it. A ~pel l ~~ has summarized the reactions taking place in ternary systems contain- ing mixtures of Ph3P, CC14, and a nucleophile that were mentioned in last year's Report. It now seems clear that the trichloromethyl compound [Ph3PCCl3]C1 is the first isolable intermediate in the Ph3P-CC1, system, but this reacts rapidly with any remaining triphenylphosphine to give the final product [Ph3P-CCl-PPh3]- Cl.145 A short-lived intermediate in the reaction is postulated to be (dichloro- methylene)triphenylphosphane, Ph,P=CCl,, and this has now been prepared by either the dechlorination of [Ph,PCCl,]Cl or the dehydrochlorination of [Ph3PCHCl,]C1.146 Further aspects of the preparative versatility of Ph3P-CC14 mixtures are found in its reactions with S-alkyl thio- or dithio-carbamates to give chlorothioformimidates R1N=CC1SR2,14' and in its dehydrating action in peptide Substitution of Ph3P by a dialkylchlorophosphine leads to a new synthetic route to the alkylphosphinates RiP(0)OR2, using a mixture of RiPCl, CC14, R20H, and a base.149 Reactions of tertiary phosphines with germanium and tin halides have been With the tetra halide^,^" the products from tri-t-butylphosphine were formulated as [Bu:PX]'[MX,]-, where X = C1 or 31 139 K. B. Dillon, M. G. C. Dillon, and T. C. Waddington, J. Inorg. Nuclear Chem., 1976, 38, 1149. R. H. Davies, A. Finch, P. J. Gardner, A. Hameed, and M. Stephens, J.C.S. Dalton, 1976. 556. 141 J. R. Durig and A. W. Cox, jun., J. Chem. Phys., 1976, 64, 1930. 14* D. K. Friesen and G. A. Ozin, J. Mol. Structure, 1976, 31, 77. D. H. Lemmon and J. A. Jackson, J. Fluorine Chem., 1976, 8, 23. 144 R. Appel, Angew Chem. Internat. Edn., 1975, 14, 801. 14' R. Appel, F. Knoll, W. Michel, W. Morback, H.-D. Wihler, and H. Veltmann, Chem. Ber., 1976, 143 109, 58. R. Appel, F. Knoll, and H. Veltmann, Angew. Chem. Internat. Edn., 1976, 15, 315. 146 14' R. Appel and K. Giesen, Chem. Ber., 1976, 109, 810. 14' R. Appel, G. Baumer, and W. Struver, Chem. Ber., 1976, 109, 801. 149 R. Appel and U. Warning, Chem. Ber., 1976, 109, 805. lSo W.-W. du Mont, B. Neudert, and H. Schumann, Angew. Chem. Internat. Edn., 1976, 15, 308. W.-W. du Mont, B. Neudert, G. Rudolph, and H. Schumann, Angew. Chem. Intentar. Edn., 1976, 15, 308. 151 Elements of Group V 193 Br and M = Ge or Sn, while base-stabilized stannylenes Bu:P:+SnX,, rather than stannylenephosphoranes BuiP-SnX,, resulted when tin(I1) halides were used. l5 ' Different behaviour towards butyl-lithium has been found with the o-bromo- and o-chloro-derivatives of benzyldiphenylphosphine, Ph2PCH2C6H4X (X = Br or Cl).lS2 In the former, the halogen atom was exchanged for lithium, but with the chloride, a-metallation occurred; these two types of compound were differen- tiated by their reactivity toward C02 and Me,SiCl. Fragmentation and rearrange- ment processes in the mass spectra of the tertiary compounds C,F,MMe, for M=N, P, or As have been elucidated, showing, inter alia, that halogen-transfer processes do not occur for M=N; this is in accord with the absence of the necessary vacant orbital^.''^ Phosphorus(v) Compounds. I n view of the current interest in .rr-bridging between phosphorus(v) atoms, the preparation of Me,P=C=PMe, by the reactions in equations (13)-(15) is pertinent.lS4 The product is very strongly basic, a powerful deprotonating agent, and a good nucleophile; its ligand properties have also been investigated. lS5 Me,P=CHSiMe, +Me,PF, + Me,P=CHPMe,F + Me,SiF (Me,P=CHPMe,)Cl +NaH + Me,P=C=PMe + H, +NaCl (13) (15) 2Me,P=CHPMe,F +CH,Cl, + 2(Me,P=CHPMe,)Cl +CH2F, (14) Tetramethylphosphonium bromide can be dehydrobrominated on reaction with sodium amide to give the ylide Me,P=CH,, but good yields of the phosphazene Me,P=NPMe,=CH, also result, probably via the imide Me3P=NNa.lS6 Among the properties of the phosphazene that have been studied is the reaction with acids to give bis(trimethylphosphorany1idene)ammonium salts [Me,P=N= PMe,]+X-. 1 : l Boron trifluoride adducts can be prepared with the ylides R,P=CH, (R=Me, Et, or Ph) and Me,P=CHSiMe,, for which full n.m.r. data have been reported.lS7 Electron-diffraction data158 for the compounds Me,MX (M = P or As; X = 0 or S) are summarized in Table 3. Although the M-S bond distances are close to Table 3 Electron-diflraction data for some compounds Me,MX Me,PO Me3PS Me,AsO Me,AsS r (M-X)/A 1.476(2) 1.940(2) 1.6 3 1 (3) 2.059(3) r(M-C)/A 1.809(2) 1.8 18(2) 1.937(2) 1.940(3) LXMCI O 114.4(7) 114.1(2) 112.6(1.3) 113.4(4) lS2 H.-P. Abicht and K. Issleib, 2. anorg. Chem., 1976, 422, 237. lS3 T. R. B. Jones, J. M. Miller, J. L. Peterson, and D. W. Meek, Canad. J. Chem., 1976, 54, 1478. lS4 0. Gasser and H. Schmidbaur, J. Amer. Chem. SOC., 1975, 97, 6281. lS6 H. Schmidbaur and H.-J. Fuller, Angew. Chem. Internat. Edn., 1976, 15, 501. lS7 E. Fluck, H. Bayha, and G. Heckmann, Z. anorg. Chem., 1976, 421, 1. H. Schmidbaur and 0. Gasser, Angew. Chem. Internat. Edn., 1976, 15, 502. C. J. Wilkins, K. Hagen, L. Hedberg, Q. Shen, and K. Hedberg, J. Amer. Chem. SOC., 1975, 97, 6352. 158 194 Inorganic Chemistry of the Main- Group Elements those expected for a normal double bond, those to oxygen are shorter, showing partial triple-bond character. This can result if charge transfer in the a-bond is partially compensated by back-flow of charge from two oxygen p-orbitals into two of the possible phosphorus d-orbitals. The bond distances shown in (9) indicate the absence of electron delocalization in the substituted phosphole ring, which has an envelope conf~rmati on.'~~ ph\ 1.505(4) / Ph (9) Dissociation and stability-constant data for a number of organophosphorus complexones have been collected, and applications of such compounds discussed in detail.160 Data are also available for the interaction between FeIr1 and the ethylenediamine derivatives ethylenediamine-NNN'N'-tetramethylenephosphonic acid and N-(2-hydroxyethyl)ethylenediamine-NN'N'-trimethylenephosphonic acid.161 With the latter, 2 : 1, 3 : 2, and 1 : 1 iron-ligand species can be obtained, depending on the pH; i.r. data have been interpreted as indicating the absence of metal-nitrogen bonds. Further phosphorus-containing analogues of edta have also been synthesized, using the method shown in equation (16).162 Oxidation yielded Ph,-,PCl, + nEt,SnCH,CO,Me + Ph,-,P(CH,CO,Me), +nEt,SnCl (16) the corresponding phosphorus(v) derivatives Ph+,P(O)(CH,CO,Me),. New data are also available on the interaction of TiCl, and SnCl, with the phosphorus analogues of p -diketones,16, cyclic molecular complexes, e. g. (lo), being obtained from the keto-form of 2-diphenylphosphinylacetophenone. Finally, the prepara- tion and n.m.r. spectra of salts of some acetylene-phosphonates, e.g. [ (MeO),( O)PC=CP( 0)( OMe)O]- and [ (MeO)O( O)PC=CP( 0)(OMe)0I2-, have been given.'64 M c14 (10) M =Sn or Ti lS9 M. Drager and K. G. Walter, Chem. Ber., 1976, 109, 877. 160 M. I. Kabachnik, I. Ya. Medved', N. M. Dyatlova, and M. V. Rudomino, Russ. Chem. Rev., 1974, 16' A. Ya. Kireeva, N. M. Dyatlova, and 0. A. Filippov, Russ. J. Inorg. Chem., 1975, 20, 637. 162 M. A. Kakli, G. M. Coray, E. G. DelMar, and R. C. Taylor, Synth. Inorg. Metal-Org. Chem., 1975, 163 A. A. Shvets, 0. A. Osipov, 0. A. Moiseeva, and E. L. Korol', J. Gen. Chem. (U.S.S.R.), 1975, 45, 43, 733. 5, 357. 1251. E. Fluck and W. Kazenwadel, 2. anorg. Chem., 1976, 424, 198. 164 Elements of Group V 195 Bonds to Silicon, Germanium, or Tin.-The barrier to internal rotation in [2H2]silylphosphine has been assessed as 1512k 26 cal mol-' from microwave data, and Raman spectra of this compound and of the hydrogen analogue have been analysed on the basis of C, symmetry.16s An analysis of similar vibrational data for the substituted silylphosphine C13SiPMe2 and the arsenic analogue points to a slight increase in the Si-P force constant compared with that in alkyl-silyl- phosphines.166 Strengthening of the Si-P bond is attributed to increased T- bonding associated with the higher electronegativity of chlorine. Methods have been reported for the preparation of a series of phosphorus or arsenic (E) derivatives of silicon, germanium, or tin (M), with formulae such as Me3ME(CF3),, Me3ME(H)CF3, and (Me3M)2ECF3.'67 The preparative approach is by either transphosphination, using HE(CF3), or H2ECF,, or the reaction of Me,SnH with either E,(CF,), or the cyclo-phosphine or -arsine (ECF,),. The displacement of trimethylsilyl groups by acyl halides from silylphosphines is a useful method for the preparation of acyl ph~sphi nes.'~~~'~~ Using PhP(SiMe,),, acetyl chloride gives PhP(COMe),, while the products with the acyl chlorides of phthalic and diphenic acids are respectively (11) and (12). In an analogous reaction with 2,3-dichloromaleic acid anhydride, chlorotrimethylsilane is also lost, but the product is the phosphorin (13).168 Pivalic chloride, Me,CCOCl, on the other hand, reacts at low temperatures with RP(SiMe,),, where R = Me, But, Ph, or cyclohexyl, to displace one Me,Si group, and although the product is initially the keto-compound (14), rearrangement takes place on warming, to give the enolic trimethylsiloxy-compound (1 5) .169 Similar displacement reactions occur with BuiPSiMe, on treatment with chlori- nated methyl~ilanes'~~ and chlor~methyl-stannanes.~~~ In the first instance three 16' J. S. Durig, Y. S. Li, M. M. Chen, and J. D. Odom, J. Mol. Spectroscopy, 1976, 59, 74. 16' R. Demuth, Z. anorg. Chem., 1976, 424, 13. 167 S. Ansari and J. Grobe, 2. Naturforsch, 1975, 30b, 523, 531, 651. 169 G. Becker, Z. anorg. Chem., 1976, 423, 242. D. Fenske, E. Langer, M. Heymann, and H. J. Becker, Chem. Ber., 1976, 109, 359. H. Schumann and W.-W. du Mont, Z. anorg. Chem., 1975,418, 259. H. Schumann, W.-W. du Mont, and H.-J. Kroth, Chem. Ber., 1976, 109, 237. 170 171 196 Inorganic Chemistry of the Main - Group Elements new silylphosphines Bu\PSiMe,Cl,-, ( n = 0-2) were isolated,17' while with equimolar quantities of Me2SnC1, and MeSnCl, the products were respectively BuiPSnClMe, and Bu\ PS~C~, M~. ' ~~ The use of two moles of the silylphosphine with MeSnC1, gave (Bu\P),SnClMe. Substitution of the chlorine atom in the stannylphosphine BuiPSnClMe, (mentioned above) by a number of reagents, including Me,SiONa, has been achieved, and its reactivity has been compared with that of the analogous germanium Monolithiated silylphosphines that are useful as intermediates are readily obtained by the action of butyl-lithium on tris(trirnethylsilyl)ph~sphine.'~~ The crystalline product obtained is (Me,Si),PLi, solvated with one mole of glyme or triglyme. Two new adamantane-type products, (Me,Ge),P, and the ethyl analogue, have been synthesized by the thermolysis of, respectively, Me,Ge(PH,), and Et2Ge(PH2)2.'74 X-Ray analysis of the methyl compound confirms the cage structure in which the GePGe and PGeP angles are 103.3 and 120.7", respec- tively; the Ge-P distance (2.317A) is that expected for a single bond. The thermolyses proceed via redistribution of the groups at phosphorus, and the intermediates (Me,GePH,),PH and (Me2GePH2)3P can be iqolated. Although the phosphorus(v) species (Me,Ge),P,O, could not be isolated, a small quantity of (Me2Ge)3P208 (16) could be isolated from the oxidation of (Me,Ge),P,. R P / I \ 0 0 0 Me,Ge / Me,Ae 'GeMe, R \o q,i \ / 0 (16) Bonds to Halogens.-Phosphorus(II1) Compounds. Ammonia reacts in the gas phase with the mixed halide PF2Cl to give diaminodifluorophosphorane as a white s01id.l~~ Vibrational data point to a trigonal-bipyramidal structure (17), with C,, symmetry, and although the conclusion drawn from n.m.r. data is that the NH2 groups are rotating rapidly at room temperature, the protons become non- equivalent on cooling the sample. New 31P n.m.r. data, particularly the observa- tion of a large doublet assigned to P-H coupling, suggest that protonation of the mixed halides PF,-,Cl, or PCl,-,Br, by HSO3F,SbF5 in liquid sulphur dioxide takes place at the phosphorus atom.176 7 #,NH2 H-7; F NH, (17) H. Schumann, W.-W. du Mont, and B. Wobke, Chem. Ber., 1976, 109, 1017. 172 173 G. Fritz and W. Holderich, Z. anorg. Chem., 1976, 422, 104. 174 A. R. Dahl, A. D. Norman, H. Shenav, and R. Schaeffer, J. Amer. Chem. SOC., 1975, 97, 6364. 17' D. E. J. Arnold and D. W. H. Rankin, J.C.S. Dalton, 1976, 1130. 176 L. J. Vande Griend and J. G. Verkade, J. Amer. Chem. SOC., 1975, 97, 5958. Elements of Group V 197 Compounds containing the unusual difluorophosphonato-group, e.g. MCl(PF,O)(PR,), have been obtained from a Michaelis-Arbuzov type of reaction of PF20F with the platinum or palladium complexes MC12(PR3)2.177 In addition, it is possible to prepare anionic difluorophosphonato-metallates, formulated as (RL), [M(PF20).J , from an alkoxy-difluorophosphine and a neutral complex MC12L2. Me Me The formation of phosphetan derivatives such as (18) from PC13, A1Cl3, and an alkene has been critically re-examined, showing that adherence to a 1: 1 : l mixture of the reactants is necessary for success.178 Deviations from these ratios lead to a number of by-products; these have been identified and their formation has been rationalized. Phosphorus halides have been shown to react smoothly with C,F,O- K' to give products such as PC12(OC6F5), PF2(OC6F5), OPF~(OC~FS), PF4(0C6F,), and PF3(OC6F,),, which are stable at room temperat~re.'~' Mixed chloromethoxy- phosphines (MeO),PCl,-, were oxidized on treatment with antimony penta- chloride, giving hexachloroantimonate salts of the cations [(MeO), PC14-n]+.180 These initial products were, however, unstable, and they rearranged to addition compounds of the corresponding phosphoryl compounds (MeO)n-lC14-n- P0,SbC15, with elimination of methyl chloride. A new method for preparation of PI3 has been discovered during an examina- tion of the high-temperature reaction between a metal iodide, a metal phosphate, and silicon dioxide;"' reactions in which the metal was europium, lanthanum, or strontium were successful. A redetermination of the crystal structure of PI3 showed almost ideal hexagonal close-packing of the iodine atoms, with phos- phorus atoms located between the octahedral and trigonal co-ordination sites, thus maintaining the pyramidal geometry in the solid state.182 The P-I bond distance is 2.463(5) A and the IPI angle 102.0(3) O. The interpretation of new electron-diffraction data for F2POPF2 differs from that of earlier The principal parameters are: P-0 1.631(10), P-F 1.568(4) A, LPOP 135.2(1.8), LOPF 97.6(1.2), and LFPF 99.2(2.4) O, with both the large POP angle and short P-0 bond distance pointing to the presence of .rr-bonding in the bridge. The thio-analogue F,PSPF, has been prepared in high yield from F,PBr and (Bu,Sn),S, and although vibrational data point to a V-shaped structure with either 177 J. Grosse and R. Schmutzler, J.C.S. Dalton, 1976, 405, 412. J. Emsley, T. B. Middleton, and J. K. Williams, J.C.S. Dalton, 1976, 979. 179 E. R. Falardeau and D. D. Desmarteau, J. Fluorine Chem., 1976, 7, 185. K.-D. Press1 and A. Schmidt, 2. anorg. Chem., 1976, 422, 266. lS1 J. M. Haschke, Inorg. Chem., 1976, 15, 508. la2 E. T. Lance, J. M. Haschke, and D. R. Peacor, Inorg. Chem., 1976, 15, 780. la3 H. Y. Yow, R. W. RudoIph, and L. S. Bartell, J. Mol. Structure, 1975, 28, 205. 178 198 Inorganic Chemistry of the Main- Group Elements C, or C, symmetry, because of the low rigidity of the P-S-P system, several rotamers are probably Although it is a potentially bidentate ligand, the product with B2H6 at room temperature is the bis-adduct of the disulphide, i.e. H3B,F2PSSPF2,BH3. A related bidentate diphosphine F2PC(CF,),0PF2 has been prepared by treating P2F4 with hexafluoroacetone. Phosphorus(v) Compounds. Core electron binding energies for the Pzp and P2, levels in PF,, OPF,, SPF,, PF3, OPCl,, SPCl,, and PCl, show regular trends related to formal charge and electr~negativity.'~~ For example, substitution of S for 0 in XPC13 causes a decrease in the Pap binding energy, and, as expected, the binding energy increases with the oxidation state of phosphorus. The fluorine 1s peak, which is sharp for both PF, and OPF,, is broad and unsymmetrical for PF,; this is taken as evidence for the presence of two types of fluorine atom, as it can be resolved into two Gaussian peaks that are separated by 1.2 eV and in the ratio 3 : 2. Detailed reaction profiles have been calculated by ab initio methods for the Berry pseudorotation process and the alternative turnstile rotation for ligand- exchange reaction, particularly in five-co-ordinate phosphoranes.186 The barrier to axial-equatorial fluorine exchange has been estimated from gas-phase Raman data to lie between 3.26 and 2.84 kcal mol-' for PF5 and 2.47 and 2.16 kcal mol-' for AsF5.18' Potassium and caesium salts of the dihydridofluorophosphate (19) have been isolated after treating the appropriate ionic fluoride with H2PF3.18' Their 19F n.m.r. spectra agree with the presence of trans hydrogen atoms, and the ten fundamental vibrational modes expected for a D4,, structure were observed. / I \ "'"I F H F Oxidative fluorination of alkyl- or aryl-phosphines R,PH3-, for R = Ph, C6Hll, or NCCH2CH2 occurred on reaction with xenon difluoride, but with the chlorides Ph,PC13-, there was also chlorine substitution, and the products were the normal phenyl fl uoroph~sphoranes.~~~ In the presence of PhPF4, phosphorus trifluoride can be inserted into the C-F bond of 1-adamantyl fluoride to produce the previously inaccessible l-adamantyltetrafluorophosphorane;19' substitution of PF, by Bu'PF, or 1-adamantyldifluorophosphine led to, respectively, l-adamantyl-t- butyl-trifluorophosphorane and bis( 1-adamanty1)trifluorophosphorane. Fluorine-exchange processes in Me2PF3, Me,PF,, Et,PF,, and (Me2N),PF3 have been re-examined by a combination of n.m.r. methods, and although it is not possible to obtain reproducible results in Pyrex tubes, data obtained in Teflon G. N. Bockerman and R. W. Parry, J. Fluorine Chem., 1976, 7, 1. 184 185 R. G. Cavell, Inorg. Chem., 1975, 14, 2828. lS6 J. A. Altmann, K. Yates, and I. E. Csizmadia, J. Amer. Chem. Soc., 1976, 98, 1450. L. S. Bernstein, S. Abramowitz, and I. W. Levin, J. Chem. Phys., 1976, 64, 3228. K. 0. Christe, C. J. Schack, and E. C. Curtis, Inorg. Chem., 1976, 15, 843. J. A. Gibson, R. K. Marat, and A. F. Janzen, Canad. J. Chem., 1975, 53, 3044. 190 J.-V. Weiss and R. Schmutzler, J.C.S. Chem. Comm., 1976, 643. Elements of Group V 199 apparatus indicate exchange via an intramolecular process. 19' This is contrary to previous results, which indicated that the exchange was intermolecular, via a bimolecular process. Interesting 19F n.m.r. spectra have been observed for the new aminophosphoranes PhPF,N(H)CHMePh and BusPF,NHPri. 192 At room temperature, each of the compounds shows four resonances associated with the axial fluorine atoms; this unusual effect is attributed to both inhibited rotation about the P-N bond and chirality in the C(H)MePh or Bus group within a non-fluxional trigonal-bipyramidal structure. The favoured structure for the new phosphorus(v) fluorides (20) is that in which the four-membered ring spans apical and equatorial positions and the phenyl group occupies an equatorial position.193 'H and 19F n.m.r. spectroscopy showed, however, that, even at the lowest temperatures, there was rapid interchange of both fluorine and ring-carbon positions. (20)R1 =R2 =H, R3 =R4 =Me R' =R2=Me, R3 =R4 =H R' =H, R2=R3 =R4 =Me New ionic compounds containing the monofluorinated phosphonium cation RiR2PF+, where R'=Me or Ph and R2=Me, Ph, or H, have been isolated as the BF; or AsF, salts from the corresponding pho~phorane.'~~~ The methylated species were converted into the corresponding hydroxy-phosphonium salts by water, while the reactions with dimethylamine yielded (Me,PNMe,)BF, and Me,PF2 from Me,PF' and Me,PNMe, and Me,NH,F from Me2PHF+.19,' The 1 : 1 complex between phosphorus pentachloride and pyrazine is ionic, and although definitive structural evidence is lacking, the authors have suggested a .rr-complex structure involving the phosphorus d,2+ orbital and the highest filled M.O. of the ring.lg5 Solid 1:l adducts also form between the substituted phos- phorus(v) chlorides R,PC15-, (R=Me, Et, or Ph; n = 1-3) and the Lewis acids BCl,, A1Cl3, PC15, and SbC15, with ionic structures of the type [R,PCl,-,]+[MCl,+,]- being supported by 31P n.m.r. and 35Cl n.q.r. data.196 Such data also point to ionic structures, i .e. [R,PCl,-,]Cl, for all the substituted phosphorus chlorides except PhPCl, and Ph2PC13, which have molecular struc- tures. The course of the reaction between PC15 and phenylacetonitrile depends on the solvent, with chlorination of the nitrile to PhCC1,CN occurring in boiling benzene but phosphorylation (giving PhCCl-CClNPCl, and finally PhCC12CC12NPC13) occurring in either chlorobenzene or carbon tetrach10ride.l~~For the 19' C. G. Moreland, G. 0. Doak, L. B. Littlefield, N. S. Walker, J. W. Gilje, R. W. Braun, and A. H. Cowley, J. Amer. Chem. Soc., 1976, 98, 2161. M. Sanchez and A. H. Cowley, J.C.S. Chem. Comm., 1976, 690. 192 193 N. S. De'ath, D. B. Denney, D. Z. Denney, and Y. F. Hsu, J. Amer. Chem. SOC., 1976, 98, 768. 194 ( a ) F. See1 and H.-J. Bassler, 2. anorg, Chem., 1975, 418, 263; ( b ) ibid., 1976, 423, 67. 196 K. B. Dillon, R. J. Lynch, R. N. Reeve, and T. C. Waddington, J.C.S. Dalton, 1976, 1243. 19' N. D. Bodnarchuk and V. I. Kal'chenko, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1007. J. N. Ishley and H. C. Knachel, Inorg. Chem., 1975, 14, 2558. 200 Inorganic Chemistry of the Main-Group Elements trifluoromethyl-chlorophosphoranes (CF3)2PC13 and (CF3),PC12, electron- diffraction data indicate trigonal-bipyramidal structures, with the more highly electronegative CF, groups preferentially occupying the apical positions.198 The reaction between chromium(v1) oxide and P203F4 initially gives an unsta- ble chromyl compound Cr02(P02F2),, which loses oxygen in the presence of excess P203F4; the final product is the chromium(rI1) compound Cr(P02F2)3.1yy Diphosphoryl fluoride also reacted with the salts K2Cr04, Na,MoO,, and Na2W04, giving K2Cr02(P02F2)4, N~,MoO,(PO,F,)~, and Na2W02(P02F2)4, re- spectively. Mixed phosphoryl chloride fluorides and the thio-analogues react with AgNS(O)F,, the chlorine atoms being replaced to form phosphoryl and thiophosphoryl sulphur oxide difluoride imides such as OPF,NSOF, and OPF(NSOF2).200 Bonds to Nitrogen.-Phosphorus(III) Compounds. It is now possible to oxidize the unusual two-co-ordinate phosphorus(II1) compound (Me,Si),NP=NSiMe, to the +5 state in MeN=P(=NSiMe,)(N(SiMe,),} without recourse to methods involv- ing azides.,'* The reaction which is brought about by triphenyl(methylimin0)- phosphorane involves transfer of a methylimino-group to the co-ordinatively unsaturated phosphorus(rI1) centre and the liberation of Ph3P. A second molecule of Ph,P=NMe can then be added to the ylidic -P=NMe group, to form the diazadiphosphetidine (2 1). The stability of these two-co-ordinate phosphazenes is conferred by the presence of bulky substituents at nitrogen, but they undergo slow cyclization at room temperature,202 the product with (Me,Si),NP=NSiMe, being the diazadiphosphetidine (22), which has a planar P2N2 ring and overall Ci symmetry (see also refs. 267 and 268). SMe3 Me :Me, Me N Me3SiN\ / \ P PPh3 (Me,Si),NP' 'PN(SiMe,), (Me,Si),N/ \N/ \ / Alkyl halides gave 1,l-addition products with the N-silylated phosph(I1I)azene as shown in equation ( 17),,03 but with either silicon tetrachloride or tetrabromide there was formation of an intermediate 1,2-addition product, namely (Me,Si),N.PX-N(SiX,)(SiMe,), which readily lost a molecule of halogeno- trimethylsilane, giving the PN,Si heterocycles (23). The final product of the R / (Me,Si),NP=NSiMe, +RX -+ (Me,Si),NP=NSMe, (1 7) ' x R=Et , Pr', or CCl, H. Oberhammer and J. Grobe, 2. Naturforsch., 1975, 3Ob, 506. S. D. Brown, L. M. Emme, and G. L. Gard, J. Inorg. Nuclear Chem., 1975, 37, 2557. 199 2oo M. Feser, R. Hoffer, and 0. Glemser, 2. Naturforsch, 1975, 30b, 327. 'O' R. Appel and M. Halstenberg, Angew. Chem. Internat. Edn., 1975, 14, 768, 769. '02 E. Niecke, W. Flick, and S. Pohl, Angew. Chem. Intenat. Edn., 1976, 15, 309. '03 E. Niecke and W. Bitter, Chem. Ber., 1976, 109, 415. Elements of Group V 20 1 corresponding reaction with tin(rv) chloride was (Me,Si),NPCl,=NSiMe,, arising from loss of SnCl, from an initial 1,2-addition compound. This dichloride can also be obtained from chlorine and the initial phosph(rI1)azene; the corresponding dibromide and di-iodide also result from similar direct oxidations with the required free halogen. SiMe, N ( 23) X = C1 or Br The 1: 1 addition compound which is formed initially between the amino- fluoride PF2NH2 and boron trifluoride loses hydrogen fluoride, giving the new fluoroborane derivative F2B[NH(PF2)].204 In the presence of an excess of PF2NH2, further reaction occurs, giving HN(PF2), and H3N,PF3 as the final products. Replacement of the halogen atoms in PCI, or PBr, by diphenylamine to give Ph2NPX2 and (Ph2N),PX has been described, along with reactions of the products with other nucl e~phi l es.~~~ The pyramidal structure of tris(1-pyrazoly1)phosphine (24) has been confirmed by X-ray data? the P-N bond length (1.714 A) indicating that there is only a small degree of interaction with the .rr-system of the ring. The rings are asymmetrically bonded to phosphorus, as shown by values of 115.0 and 135.4”, respectively, for the PNN and PNC angles. H HC-CH (24) The conformation about the P-N bond in both the triphosphazenes (Ph2P.NR)2PPh (R = Me or Et) and the diphosphino-amines Ph2P.NR.PPhCl (R = Me, Et, Pr, etc.) is likely to be influenced by the steric properties of the R group attached to nitrogen, and this is considered to be the major reason for the marked dependence, in the 31P n.m.r. spectra, of J (PNP) on the nature of R.207 As an example, in the triphosphazenes, J changes from 280 to 25 Hz when the methyl groups on nitrogen are replaced by ethyl. A novel tetrazene which contains one phosphorus atom has recently been synthesized by the reaction shown in equation ( 18),208 the 2-phospha-1-tetrazene Cl,PNBu‘(SiMe,) +Me,NN(SiMe,)Li + Me,N-N(SiMe,)P=NBu’+ LiCl+ Me,SiCl (18) ’ 04 D. E. J. Arnold, E. A. V. Ebsworth, and D. W. H. Rankin, J.C.S. Dalron, 1976, 823. ‘ 05 H. Falius and M. Babin, Z. anorg. Chem., 1976, 420, 65. ’M R. E. Cobbledick and F. W. B. Einstein, Acta Cryst., 1975, B31, 2731. ‘ 07 R. J. Cross, T. H. Green, and R. Keat, J.C.S. Dalton, 1976, 1424. *08 0. J. Scherer and W. Glassel, Angew. Chem. Internat. Edn., 1975, 14, 629. 202 Inorganic Chemistry of the Muin-Group Elements structure being confirmed by n.m.r. data. Attempts to isolate the isomeric 2-tetrazene, however, led to the diazadiphosphetidine (25). NMe, N MeBu'N-F" ' P-NBu'Me I New compounds based on the replacement of the chlorine atoms in the cyclic hydrazinophosphine (26) by Me, OMe, SMe, and CN groups have been iso- lated?O9 and the phosphorus atoms in the P-methyl compound can be oxidized to the +5 state by oxygen, sulphur, selenium, or tellurium. Treatment of (26) with aluminium trichloride gave an adduct regarded as a tetrachloroaluminate of a cation containing a two-co-ordinate phosphorus(II1) atom, while bicyclic products (27) were obtained on treatment with (Me3Si),NMe, (Me3Si),S, or H20. Bicyclic products (27; X = NHNH or NHNMe) could also be produced by reaction with, respectively, hydrazine and methylhydrazine. Compound (26), according to an X-ray structure, has almost C,, symmetry, with a flattened-chair ring conforma- tion, the chlorine atoms and methyl groups occupying the expected equatorial positions.210 The related heterocycle (28) also has a non-planar ring system,211 but with C, symmetry; the chlorine atoms are on different sides of the ring. Me Me Me Me M e (26) (27) X =NMe, S, or 0 (28) Phosphorus(v) Compounds. The reactivity of triphenylphosphinimine, Ph3P=NH, toward acyl chlorides212 and phosphorus has been investigated. With the former it gives products of the type Ph,P=NCOR. Cyanuric chloride, N3C3C13, also reacts readily, one chlorine atom being replaced; further substitu- tion takes place slowly, and although the disubstitution product N3C3CI(NPPh3), was isolated, complete replacement of chlorine was apparently not possible.212 Phosphorus(v) chlorides react similarly with Ph3PNH, and compounds such as OP(N=PPh3)3, OPR(N=PPh3),, and OP(OR),(N=PPh,) can be Phosphorus(II1) chloride and the silylimide Ph,P=NSiMe, gave the trisubstitution product P(N=PPh3),, which did not show typical phosphorus(II1) behaviour, probably due to shielding by bulky Ph3PN groups.213 With phenyldichloro- phosphine, on the other hand, the product was a stable complex between '09 H. Noth and R. Ullmann, Chem. Ber., 1976, 109, 1942. H. Noth and R. Ullmann, Chem. Ber., 1976, 109, 1089. 'I1 R. Ullmann and H. Noth, Chem. Ber., 1976, 109, 2581. 'I2 M. Biddlestone and R. A. Shaw, J.C.S. Dalton, 1975, 2527. A. S. Shtepanek, V. A. Zasorina, I. N. Zhmurova, and A. P. Martynyuk, J. Gen. Chem. (U.S.S.R.), 1975, 45, 999. 213 Elements of Group V 203 PhP(N=PPh,), and Me3SiC1. A number of new N-silylphosphinimines have been synthesized from R3P=NSiMe3 (R = Me, Et, Pr", etc.) by reaction with Et3SiC1214" or ClSiMe2SiMe2C1.214b In all cases, chlorotrimethylsilane is eliminated, and the remaining chlorine atom in the disilane derivative R3P=NSiMe2SiMe,C1 can be methylated with methyl -l i thi ~rn.~~~" A final report in this area concerns the insertion of sulphur trioxide into the Si-N bond of N-silylphosphinimines to give a series of amidosulphuric esters R1R2P=NS020SiMe3.215 The use of a bifunc- tional phosphinimine, e.g. CH2(PPh2=NSiMe3),, led to the loss of bis- (trimethylsilyl) sulphate and the formation of the phosphazasulphone (29). Ph P-N 3 \ H2C\ , so2 Ph2P=N (29) The reaction between PC15 and benzylamine hydrochloride, which in a CC14 medium leads to the diazadiphosphetidine (PhCH2NPC13),, has been reinvesti- gated in the absence of solvent. It was shown that the sole products are benzyl chloride and the chlorocyclophosphazenes (PNC12),,4.216 The thermodynamic data on the formation of 'phospham' (PN2H) from the reaction of red phosphorus and ammonia at temperatures close to 500 "C, shown in equation (19), point to the feasibility of preparing amino-phosphazenes via the high-pressure reaction shown in equation (20).'17 Thus a route may be opened from ammonia and phosphorus to some amino-phosphazenes that are currently being evaluated as ultra-high-analysis fertilizers. 4NH3 (g) + 2P (red) + 2PN,H (s) +5H2 (g) nNH3 (g) +(PN2H)n (s) + PN(NH2)Jn (s) (19) (20) A number of references relate to new phosphorus(v) hydrazine derivatives. For example, P-H groups can be added across the N=N double bond of an azo-ester such as EtO,CN=NCO,Et to give Ph,P(O)NRNRH; in a similar fashion, the arsenic and antimony compounds PhzMNRNRH (M = As or Sb) can be obtained from Ph2MH.218 The structure of the cis-form of the cyclic dihydrazide (30) shows a twist conformation, compared with a chair form for the analogous truns- isomer.219 Phosphonothioic dihydrazides R1P(S)(NHNH2),, on reaction with LY - diketones, gave products (3 1), containing a new seven-membered heterocyclic (30) (3 1) 214 ( a) W. Wolfsberger, 2. Naturforsch., 1975, 30b, 900; ( b) p. 904; (c) p. 907. 215 R. Appel, I. Ruppert, and M. Montenarh, Chem. Ber., 1976, 109, 71. 216 C. Glidewell, Angew. Chem. Internat. Edn., 1975, 14, 826. 217 J. M. Sullivan, Inorg. Chern., 1976, 15, 1055. 218 K. H. Linke and W. Brandt, Angew. Chem. Inrernar. Edn., 1975, 14, 643. 219 U. Engelhardt and H. Hartl, Acta Cryst., 1976, B32, 1133. 220 A. F. Grapov, 0. B. Mikhailova, and N. N. Mel'nikov, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1362. 204 Inorganic Chemistry of the Mai n -Group Elements A novel compound, 1,2-bis(tetrafluorophosphorano)dimethylhydrazine, F,P.NMeNMe.PF,, has been prepared by a reaction involving the loss of two moles of fluorotrimethylsilane between PF5 and the silyl hydrazide Me,SiNMeN- MeSiMe3.,,l Conformational effects have been explored by variable-temperature n.m.r. spectroscopy, which indicates non-planarity of the PN2P unit and that N-N bond rotation, in addition to P-N torsion and fluorine exchange, are slow at low temperatures. Tris(amin0)phosphoranes (R'R;N),PCl, are little known, and few have been isolated in the solid state, but recently a number have been prepared by reactions of tris(amino)phosphines with the stoicheiometric amount of chlorine in benzene Evidence has been presented for either an ionic structure (R'R2N),PC1+C1- or an equilibrium involving an ionic form; one chlorine atom can be replaced on reaction with KI, NaClO,, or KNO,, giving (R1R2N),PC1' X- (X = I, ClO,, or NO,) as stable, non-hygroscopic compounds. The expected product (Me,N),P=NSiMe, was obtained by treating tris(dimethy1amino)phosphine with Me3SiN3, but this reaction also proceeded with elimination of Me3SiNMe,, and the new diphosphorane (Me,N),P= P(NMe,),=NSiMe, was Analogous reactions with trimethyl phosphite again led to two products, in this case the expected phosphinimine (MeO),P= NSiMe, and the isomeric derivative (MeO),P(O)NMeSiMe,. The primary product from the reaction between an azide and a tertiary phosphine (Staudinger reaction) is generally not isolable, owing to its ready loss of nitrogen, but in a number of cases that have been reported this year, isolation has been achieved. With triphenylphosphine and azidoformamidinium chloride, the compound isolated initially was [Ph3P=NNNC(NH2),]+Cl-, which lost nitrogen slowly to give [Ph,P=NC(NH,),]+ Cl-.,,, Similarly, the amino-phosphines (Me,N),P, MeC(CH,NMe),P, or P(NMeNMe),P gave products of the type R,P= NN=NPh with phenyl a~ide.,,~ The final products, after loss of one mole of nitrogen, for these compounds and for those prepared from the three phosphines on reaction with both (PhO),P(O)N, and Ph,P(O)N, have been characterized by P n.m.r. spectra. A new interpretation as an AA'XX' system has been proposed for the compound R,P(O)N=P(NMeNMe),P=NP(O)R,. I n continuation of his work on azides, Schmidt and his co-workers have now isolated compounds of the type OP(OMe), (N3),-,, and OP(NMe2),,(N3),-,,, where n = 1 or 2, from reactions between the corresponding chlorides and sodium azide in acetonitrile.226 Similar reactions in pyridine at room temperature gave the stable azides R,P(X)N,, where R=Me or Et and X =O or S.,,' Sodium cyanamide, NaHNCN, in ether has been shown to react as a pseudo- chalcogenide with phosphorus(v) chlorides, allowing the isolation of OPCl,(NHCN), OPCl(NHCN),, and P203C14-, (NHCN),, where n = 1-4.228 The 221 R. Goodrich-Haines and J. W. Gilje, Inorg. Chem., 1976, 15, 470. 31 A. M. Pinchuk, A. P. Marchenko, I. N. Zhmurova, and A. P. Martynyuk, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1002. 222 223 0. Schlak, W. Stadelmann, 0. Stelzer, and R. Schmutzler, Z. anorg. Chem., 1976,419, 275. 224 W. Buder and A. Schmidt, Z. Naturforsch., 1975, 309 503. 225 R. D. Kroshefsky and J. G. Verkade, Inorg. Chem., 1975, 14, 3090. W. Buder, K.-D. Pressl, and A. Schmidt, Z. anorg. Chem., 1975, 418, 72. H. F. Schroder and J. Miiller, Z. anorg. Chem., 1975, 418, 247. H. Kohler and U. Possel, Z. anorg. Chem., 1976, 423, 21. 226 227 Elements of Group V 205 products are viscous liquids which yield the sodium salts of cyanamido-mono- and -di-phosphates [PO4-, (NCN),I3- (for n = 1 or 2) and [P20,-,(NCN),]4- (for n = 1 4 ) on treatment with sodium hydroxide. The pseudo-chalcogenide behaviour was further demonstrated in the reactions of Na2NCN with P401,.22g At elevated temperatures, the products are the cyanamido-diphosphates Na,P,O,-,,(NCN), mentioned above and a cyanamido-ultraphosphate, depending on the molar ratio of reactants. A mechanism based on stepwise cleavage of the P-0-P bridges in P,O,, has been suggested. These reactions were also carried out in aqueous alkali, when the products were again cyanamido-diphosphates. Compounds containing P-N Rings. As in previous years, these compounds constitute a sizeable section of the material mentioned in the Report. Compounds with ring systems containing a third element are discussed in the next section. The oxygen and sulphur compounds C12P.NMe.P(X)C12 behave differently on reaction with t-b~tyl ami ne.~~' In each case, cyclization took place to give products with P2N2 ring systems, but with the phosphoryl derivative a dichloride (32) resulted, while the sulphur compound gave the monochloride (33). Analogous t-butylamine- or isopropylamine-promoted cyclization reactions were carried out on the methylene-bridged compound bis(dichlorophosphinoy1)methane; the pro- duct was a mixture of the geometrical isomers of compound (34). Recent 35Cl n.q.r. measurements on compounds of the type (C13PNR)2, where R=Me, Et, or Ph, have provided three methods for distinguishing axial from equatorial chlorine In the first instance, the resonance frequencies are different, but both the temperature and the pressure coefficients of to be different. Me Me N O N S / \p/ ClP/ \PY BuWP \N/ \C1 But \N/ \C1 But (32) (33) these frequencies are also found 0 E2 0 XP/ \p/ c1/ \*' \c1 R (34) R = But or pr' The gauche-trans equilibrium in the substituted diazadiphosphetidines (35) has been investigated by means of a detailed 19F and 31P n.m.r. Among the parameters evaluated was 'J(P-P), which, particularly for the t-butyl derivative, showed a large isomer shift. Substituent effects in the mixed chloride fluorides (36) have been similarly investigated.233 F N F \ / \ / Me Me N / ? \ O - p F-P P-F F,CI,_,P/ \PC13-,F. F3P 1, ' N ' ' F Me "/ / \N/ \R R Me Me (35) R = Me, Et, Pr', or But (36) m, R =0-3 (37) 229 H. Kohler, R. Uebel, U. Lange, and U. Possel, Z. anorg. Chem., 1976, 423, 1; H. Kohler and U. uo G. Bulloch and R. Keat, J.C.S. Dalton, 1976, 1113. 231 W. H. Dalgleish and A. L. Porte, J. Magn. Resonance, 1975, 20, 359. 232 R. K. Harris, M. I. M. Wazeer, 0. Schlak, and R. Schmutzler, J.C.S. Dalton, 1976, 17. "' R. K. Harris and M. I. M. Wazeer, J.C.S. Dalton, 1976, 302. Lange, ibid., p. 15. 206 Inorganic Chemistry of the Main-Group Elements In the catechol-substituted compound (37), which was synthesized from (F,PNMe), and the di-lithium derivative of catechol, n.m.r. measurements showed that the fluorine atom at the substituted phosphorus atom occupies an equatorial The reason for such behaviour in this and in similar compounds is probably associated with the lower ring strain in the phosphorus-catechol system when the oxygen atoms occupy axial and equatorial positions. A new h3A5- diazadiphosphetidine (38) has been prepared by the oxidation of the h3A3- compounds (39) with biacetyl, and although, at low temperatures, an excess of biacetyl leads to the A5A5-product (40), this compound is converted into the monophosphazene (41) within 24 hours at room temperat~re.’~’ The thermo- dynamic instability of the dimer (40) follows from the presence of bulky substituents on the nitrogen atoms and electron-donating groups at phosphorus. Me,Si Me,Si N SiMe, (40) (41) The reactions of P3N3Cl, and P4N4C18 with nitrogen bases, and the properties of the resulting compounds, have been reviewed.236 Attention has also been drawn to the problem of transannular bonding in cyclophosphazenes and the possibility of rationalizing a number of the physical properties of these compounds in terms of the Dewar island model for r-b~nding.’~’ The importance of non-bonded interactions in rationalizing the large angles at nitrogen and carbon in cyclo- phosphazenes and phosphorus ylides, etc. has been In phosphazenes the P * - - - P distance is always close to 2.90 A, and it is possible to reproduce accurately the endocyclic PNP angles if one uses this value and the observed P-N ring bond distance. Althougn thermal polymerization of (PNX2)3 compounds is known for X = F, C1, Br, or NCS, such reactions are not possible with other derivatives. Further clarification of this problem comes now from an investigation of the polymeriza- tion properties of P3N3F,Ph, gem-P3N3C14Ph2, P3N3F4Ph2, P3N3C12Ph4, P,N3Ph5Cl, P3N3Ph6, and n~n-gem-P,N,Cl,Ph,.~~~ Although only the first corn- pound can be homopolymerized, the di- and tri-phenyl compounds can be 234 R. K. Harris, M. I. M. Wazeer, 0. Schlak, and R. Schmutzler, J.C.S. Dalton, 1976, 306. 235 W. Zeiss, Angew. Chem. Internat. Edn., 1976, 15, 555. 236 R. A. Shaw, Z. Naturforsch., 1976, 3lb, 641. 237 J.-P. Faucher, J.-F. Labarre, and R. A. Shaw, Z. Naturforsch., 1976, 3lb, 677. 238 G. Glidewell, J. Inorg. Nuclear Chem., 1976, 38, 669. H. R. Allcock and G. Y. Moore, Macromolecules, 1975, 8, 377. 239 Elements of Group V 207 copolymerized with P,N3C16; steric effects are most probably the cause of inhibi- tion of polymerization with increased phenylation. Although antimony trifluoride alone is not a sufficiently powerful fluorinating agent to react with P3N3C16 and the higher members of this series, admixture with SbC15 led to the formation, in moderate yields, of the monofluorides P,N,Cl,,-,F for n = 3-6.240 The more reactive tetramer and hexamer gave difluorides with non-geminal structures also. Structures have been reported for two trimeric compounds containing two different substituents, i.e. gern-P3N3F4(NH2)2241 and P3N3C12(NHPr’)4.242 In each case, the ring bond distances vary in a manner consistent with the known effects of the ring substituents. The structure of the isopropylamine derivative is impor- tant, as it is now possible to assess the changes in structure occurring when protonation to P3N3C1(NHPr’),,HCl takes place. In addition to the normal substitution products, a small quantity of a new type of phosphazene (42) has been isolated from reactions between P3N3C16 and di eth~l ami ne.~~~ Traces of moisture are necessary for its formation, and a dimeric structure resulting from the presence of two N-H - - - -0 bonds has been comfirmed by an X-ray structure. The ring bond lengths show (as expected) both phosphazene and phosphazane character. Steric effects have been shown to be very important in determining the course of the reaction between P3N3C16 and the bulky secondary amine (PhCH2)2NH.244 Only mono- and di-substituted products can be isolated, but these will react further if, for example, dimethylamine is used; the pentasubstituted compound P3N3CIN(CH2Ph)2(NMe2)4 so isolated contrasts markedly in its stability with previously obtained analogues that are readily attacked by traces of moisture. With benzylamine, replacement of chlorine is much easier, giving the products P3N3Cl6-,(NHcH2Ph),, where n = 1,2,4, or 6. Et,N NEt, \ P/ (42) Details of the mechanism of the reaction of chlorophosphazenes with ortho-di- nucleophiles such as catechol or o-aminophenol have been Although it is not possible to isolate the substituted phosphazene (43a), good evidence is available for its initial formation from isolation of the spiro-phosphorane (44) and an imino-intermediate (45). Complete investigation of this system is thus difficult, but further aspects of the reaction paths were elucidated by studying the reaction of o-aminophenol with the tri-catechol derivative (43b). A non-geminal structure has been assigned, on the basis of 31P n.m.r. measurements, to the disubstituted 240 N. L. Paddock and D. J. Patmore, J.C.S. Dalton, 1976, 1029. 241 S. Pohl and B. Krebs, Chem. Ber., 1976, 109, 2622. 243 G. J. Bullen, P. E. Dann, M. L. Evans, M. B. Hursthouse, R. A. Shaw, K. Wait, M. Woods, and H. S. 244 Masood-ul-Hasan, R. A. Shaw, and M. Woods, J.C.S. Dalton, 1975, 2202. 245 H. R. Allcock, R. L. Kugel, and G. Y. Moore, Inorg. Chem., 1975, 14, 2831. W. Polder and A. J. Wagner, Cryst. Struct. Comm., 1976, 5, 253. Yu, 2. Naturforsch, 1976, 31b, 995. 242 208 Inorganic Chemistry of the Main - Group Elements phosphorylamido-compound P,N,Cl,[NMeP(O)(OEt),],, but the corresponding trisubstituted derivative is the geminal isomer.246 (43) a,X=NH b. X =O (45) The extension of basicity measurements to phosphazenes carrying triphenyl- phosphazenyl substituents, i.e. P3N3XnY5-,,(NPPh3), allows the sub-division of these compounds into two classes, depending on the position of pr~tonati on.~~’ Type I behaviour implies protonation at a ring nitrogen atom, and occurs when the second substituent at the phosphorus atom carrying the NPPh3 group is either chlorine or a second NPPh, group. If the second substituent is either NH2 or NMe,, protonation occurs in the first instance at the nitrogen of the phosphazenyl group (type I1 behaviour). These two types of behaviour have been related via X-ray crystallographic measurements to the orientation of the NPPh3 group. The type I behaviour of P3N3C15(NPPh,) is thus associated with near coplanarity of the N-P bond of the substituent and the nitrogen atoms of the ring segment.,,* This should be contrasted with the situation in P3N3C14Ph(NPPh3), where the N-P bond is perpendicular to the local ring segment. In this connection it is interesting that the s-triazene derivative (46) obtained from Ph3P=NH and C3N3C12NMe2 has a type I c~nf ormati on.~~~ New fluorophosphazenes containing NPPh3 sub- stituents have been reported from reactions of P3N3F6-,,Xn (X=Ph, NMe,, or OH; n = 1 or 2) with Me3SiNPR3 (R= Me or Ph).250 C-N \ c1 Me2N (46) B. Thomas, P. Gehlert, H. Schadow, and H. Scheler, 2. anorg. Chem., 1975, 418, 171. Y. S. Babu, T. S. Cameron, S. S. Krishnamurthy, H. Manohar, and R. A. Shaw, Z. Naturforsch., 1976, 31b, 1001. 246 247 S . N. Nabi, M..Biddlestone, and R. A. Shaw, J.C.S. Dalton, 1975, 2634. 248 249 T. S. Cameron, K. Mannan, M. Biddlestone, and R. A. Shaw, 2. Naturforsch., 1975, 30b, 973. 2so J. A. K. Du Plessis, H. Rose, and R. A. Shaw, 2. Naturforsch., 1976, 31b, 997. Elements of Group V 209 Nine compounds in the series P3N3cl6-,,(OCH2CF3),,, with n = 1-6, have been isolated by substitution of the chlorine atoms in P3N3C16 by reaction with sodium 2,2,2-trifluoroetho~ide.~~~ Isomer configurations have been assigned, and a trans- non-geminal replacement scheme has been shown to predominate, indicating that steric effects dominate the substitution pattern. In similar reactions with the truns- non-geminal isomer P3N3C14(NMe2)2, stepwise replacement of chlorine occurs, with the formation of the compounds P3N3C14-,,(NMe2)2(OCH2CF3)n (n = 2- 4).252 A spiro-product (47) was formed by loss of hydrogen chloride between the geminal diamine P3N3(OCH2CF3)4(NH2)2 and dichloromethylsilane.253 (CF,CH20)2 H /p-N\p/ N \si/ Me N \ / \N/ \H P=N (CF3CH2O) 2 H (47) A number of new, completely substituted, aryloxy-derivatives of both the trimer and tetramer have been Investigation of electrophilic substitu- tion into the phenoxy-group in P3N3(OPh), led to the isolation of the para- substituted compound under normal conditions, but further substitution into the ortho-position was achieved under more forcing conditions. A re-examination of the reaction of DMSO with the chloro- and fluoro-phosphazenes (PNX2)3 and (PNX,), has provided evidence for a stepwise process, with the formation of di-, tri-, tetra-, and hexa-hydroxy-species P3N3C16-,, (OH),, in addition to the halogenome thyl me thyl sulp hide .255 A convenient method for preparation of the fully methylated triphosphazene involves heating the oil, probably (Me,PClNMe),, that is initially obtained by treating Me2PC13 with methylamine hydr~chl ori de.~~~ The product is the salt P3N3Me,,MeCl, which on pyrolysis at 200 "C and 0.1 Torr gives the free com- pound. A small amount of the tetramer P4N4Me,,2MeCl is also formed. Loss of lithium chloride Ph* P=N Cl t between (48) and (49) led to the di(triphosphazeny1) 251 J. L. Schmutz and H. R. Allcock, Inorg. Chem., 1975, 14, 2433. '" M. A. Andreeva, L. M. Gil'man, A. S. Lebedeva, V. V. Korshak, and S. V. Vinogradova, J. Gen. 253 M. Kajiwara, M. Makihara, and H. Saito, J. Inorg. Nuclear Chem., 1975, 37, 2562. 254 P. 0. Gitel', L. F. Osipova, and 0. I. Solovova, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1714. 255 E. J . Walsh, S. Kaluzene, and T. Jubach, J. Inorg. Nuclear Chem., 1976, 33, 397, 256 R. T. Oakley and N. L. Paddock, Canad. J. Chem., 1975, 53, 3038. Chem. (U.S.S.R.), 1975, 45, 1261. 210 Inorganic Chemistry of the Main- Group Elements derivative (50) according to equation (21).257 The compound has a centro- symmetric structure in which the phosphazene rings are similar to those in P3N3Ph6. The conversion of the hydrido-phosphazene (51) into the thione (52) by reaction with sulphur has been the latter giving complexes with Ni, Pd, or Pt dichlorides. Methylation of the substituted phosphazenes (53) was shown to occur at the nitrogen atom flanking the PR'R2 group.259 Ph2 Ph2 H Ph2 N 4P-N\p/ R N /P-N\p/ R N 4P-N\p/R1 \p=N/ \H \ P=N / NS \ P=N / \R2 Ph2 Ph2 Ph2 (51) (52) (53) R', R2 =Me or NH, Details of the determination of crystal structures for hydrated trimeta- phosphimic acid [H3(P02NH),,2H20] and the monoammonium salt NH, H,(PO,NH),,MeOH have been published.260 The ring systems in both com- pounds have a boat conformation (see Figure 3 for details of the structure of the acid), with mean values of 104.2 and 125.8", respectively, for the endocyclic angles at phosphorus and nitrogen. The mean P-N bond distance is 1.652 A, and there is an extensive system of hydrogen-bonding. In the structure of a penta- substituted tetraphosphazene, P4N4C13(NMe2)5, the three chlorine atoms were unexpectedly found to be in cis-positions,261 but the ring bonds varied in length pairwise in an order that was expected from the predicted variation in ring 1.4 Figure 3 The structure of trimetaphosphimic acid dihydrute, H3(P0,NH),,2H20 (Reproduced by permission from Z. anorg. Chem., 1976, 419, 139) 257 A. Schmidpeter, J. Hogel, and F. R. Ahmed, Chern. Ber., .1976, 109, 1911. A. Schmidpeter, K. Banck, and F. R. Ahrned, Angew. Chem. Internat. Edn., 1976, 15, 488. 259 A. Schmidpeter and H. Eiletz, Chem. Ber., 1976, 109, 2340. R. Attig and D. Mootz, Z. anorg. Chem., 1976, 419, 139. 261 T. T. Bamgboye, M. J. Begley, and D. B. Sowerby, J.C.S. Dalton, 1975, 2617. 258 Elements of Group V 211 .rr-bonding. The ring conformation was irregular, but could be described in terms of a crown segment associated with the three cis-PCl(NMe,) groups and a saddle segment covering the PCl(NMe,)P(NMe,),PCl(NMe,) grouping. Seven partially substituted ethylamine derivatives, including P,N,(NHEt),, have been isolated from reactions with P4N4C18, but although from one to four chlorine atoms can be replaced, giving non-geminal products, it was not possible to isolate penta- and hexa-substituted compounds.262 The partially substituted compounds reacted further to give either methoxy- or dimethylamino-derivatives, and, from a reaction between P4N4C16(NHEt)2 and an excess of dimethylamine in chloro- form, the unusual bicyclic phosphazene (54) was isolated.263 Crystallographic data established the structure, showing in addition that the bridgehead P-N distances were non-equivalent. A second tetraphosphazene with a 175-bridge ( 55) has been prepared from the 1,5-diamino-hexafluoride by successive treatment with SOCl, and ~yridine.,~, (5 4) ( 55) A perspective view of the molecule P8N8(NMe2)16 is shown in Figure 4.265 The molecule lies on a centre of symmetry and has a ring conformation consisting of two almost planar seven-atom segments joined by a step at N(1)-N(l'), similar to Q Figure 4 The SfrUCt Ure Of P,N,(NMe,),6 (Reproduced from J.C.S. Dalton, 1976, 38) 262 S. S. Krishnamurthy, A. C. Sau, A. R. V. Murthy, R. Keat, R. A. Shaw, and M. Woods, J.C.S. Dalton, 1976, 1405. T. S . Cameron, Kh. Mannan, S. S. Krishnamurthy, A. C. Sau, A. R. V. Murthy, R. A. Shaw, and M. Woods, J.C.S. Chem. Comm., 1975, 975. 264 H. W. Roesky and E. Janssen, Angew. Chem. Internat. Edn., 1976, 15, 39. H. P. Calhoun, N. L. Paddock, and J. Trotter, J.C.S. Dalton, 1976, 38. 263 265 212 Inorganic Chemistry of the Main-Group Elements that found earlier for P8N8(OMe)l,. The P-N-P ring angles fall between 145.9 and 170.2", the latter being the largest value observed so far in this type of compound. Repulsive forces between dimethylamino-groups are a factor deter- mining the ring conformation, but, as found for the corresponding methoxy- compound, attractive forces are probably of equal importance. Compounds containing Other Ring Systems. Compounds containing a four- membered PN2Si ring ( 56) were formed when organo-trichloro- or diorgano- dichloro-silanes reacted with the two-co-ordinate phosphorus(II1) compounds (Me,Si),NP=NR1 ,266 and a similar reaction between Buf(Me3Si)NP=NBu' and arsenic trichloride led to compound (57).267 The reaction proceeds via the intermediate Bu'(Me,Si)NPC1NBufAsC12 in the latter case. R' But N R3 N CIP' \si/ ClP/ 'AsCl ' N' \Rz \ N/ SiMe, But (56) R'=Me,Si or But (57) R2 =Me, Et, or Ph R3 =C1or Me A ready synthesis of the mono-carbon substituted triphosphazene (58) from cyanamide and [C13PNPC1,]C1 now completes the series of mixed cyclic com- pounds in the P3N3/C3N3 systems,268 allowing a full discussion of the vibrational spectra for the complete series of The two six-membered carbon- containing heterocycles (59) and (60) can also be obtained by treating the halo- genoethylimido-derivative CX3CC12N=PC13 with ammonium chloride in the pres- ence of a small quantity of aluminium ( 32 \ / P=N N //p-N\cc, c12 N //P-N\CCx3 \ / P=N c12 (59) X=For C1 cx3 I N "C-N\Pc,2 \ / C=N I cx3 (60) X =F or C1 The P2SN3 ring in (61) has a boat conformation, with the oxygen atom occupying an equatorial in contrast to the chair conformation with two equatorial oxygen atoms found previously for the corresponding (SOCl)2PC12N3 heterocycle. Reactions of the latter with n-, s-, and t-butylamine have been rationalized in terms of the increased difficulty in forming a five-co-ordinate phosphorus intermediate as the steric requirements of the amine increase.272 The 266 u. Klingebiel, P. Werner, and A. Meller, Monatsh., 1976, 107, 939. 0. J. Scherer and G. Schnabl, Z. Naturforsch., 1976, 31b, 142. 268 E. Fluck, E. Schrnid, and W. Haubold, Z. Naturforsch., 1975, 30b, 808. 269 J. Weidlein, E. Schrnid, and E. Fluck, Z. ancvg. Chem., 1976, 420, 280. 270 G. Schonig and 0. Glemser, Chem. Ber., 1976, 109, 2960. F. van Bolhuis and J. C. van de Grampel, Acta Cryst., 1976, B32, 1192. J. B. van den Berg, E. Klei, B. de Ruiter, and J. C. van de Grampel, Rec. Trau. chim., 1976,95, 206. 267 271 272 Elements of Group V 213 SS’-difluoride (SOF),PC12N3, on reaction with potassium thiocyanate, gave a mono-isothiocyanate as a mixture of two isomers, but the major product was (SOF)2P(NCS)2N3 .273 Me,%-SiMe, / \ .N 0 c12 P- A number of new silicon-containing mono- and bi-cyclic derivatives, including (62), have been synthesized, and their reactivity has been assessed.274 In the course of this work the eight-membered phosph(rI1)azane (MeNPMe), was pre- pared from MeN(PMeCl), and (MeNH),SiMe, by successive loss of dichloro- dimethylsilane and methylamine. Bonds to Oxygen.-Compounds of Lower Oxidation State. The chemistry of hypophosphorous acid and the metal hypophosphites has been reviewed.275 Improved dimensions for the HP0,OH- ion have been reported in a neutron- diffraction investigation of the structure of LiH2P0,; in particular, the P-H distance has been revised to 1.396A and the presence of strong hydrogen bonds defined.276 Phosphorus(rI1) oxide will displace carbon monoxide from Fe(CO), on heating in diglyme, giving a mixture of (OC),Fe(P,O,), tr~ns-(OC)~Fe(P,0,)~, and P407, but with Fez(C0)9 in THF and in an atmosphere of carbon monoxide the products were members of the series [(OC),Fe],P,O,, where n = 1-4.277 Aqueous solutions of phosphorus oxy-acids have been found to react with organo-tin chlorides to give compounds such as the hypophosphite Me,SnPO,H,, the hydrated phosphite (Me3Sn),P03H,2H20 (together with the anhydrous com- pound), and the phosphate (Me,Sn),PO,, as a dioxan addu~t.’ ~~ Mossbauer and vibrational data were consistent with a trigonal-bipyramidal polymeric structure (63) for the hypophosphite, and five-co-ordination was also suggested for the phosphites. Bis(trifluoromethyl)phosphorus(rII) halides, on reaction with the sodium cyanohydrin salt of hexafluoroacetone, gave (CF,),C(CN)OP(CF,), as the product, and similar reactions with silver perfluoroalkylcarboxylates gave the mixed anhydrides R,C(O)OP(CF,),, where Rf = CF,, C2F5, or C,F,.279 An unusual five-co-ordinate phosphorus cation (64), analogous to the silatranes, has been 273 E. Klei and J. C. van de Grampel, Z. Nuturforsch., 1976, 31b, 1035. U. Wannagat and H. Autzen, Z. unorg. Chem., 1976, 420, 119, 132, 139. 275 N. V. Romanova and N. V. Demidenko, Russ. Chem. Rev., 1975, 44, 1036. 276 G. B. Johansson and 0. Lindqvist, Actu Cryst., 1976, B32, 412. 277 M. L. Walker and J. L. Mills, Inorg. Chem., 1975, 14, 2438. *’’ T. Chivers, J. H. G. van Roode, J. N. Ruddick, and J. R. Sams, Cunud. J. Chem., 1976,54, 2184. 279 D. W. McKennon and M. Lustig, J. Fluorine Chem., 1976, 7, 321. 274 214 Inorganic Chemistry of the Main- Group Elements identified from a crystallographic investigation of the product from the reaction of P(OCH2CH2)3N with Me30' BFq.280 H Me I / \ -Sn-0 0- Me d '''Me Phosphorus(v) Compounds. Although the monomeric PO, ion is severely electron-deficient, S.C.F. M.O. calculations have indicated a greater overlap population in both the u- and v-systems for this species than in the isoelectronic nitrate ion.281 In view of this, it has been suggested that kinetic rather than thermodynamic reasons should be sought for the instability of PO,. The forma- tion of monomeric methyl metaphosphate, MeOPO,, reported in an earlier volume, has now been substantiated by identifying the methyl ester of p-diethyl- aminobenzenephosphonic acid as the product from the reaction with NN-diethyl- aniline at low temperatures.282 Substitution into the aromatic ring provided a measure of the electrophilicity of the monomer. Ionic structures with slightly distorted Me,Sb' cations were suggested, after consideration of the n.m.r. and vibrational spectra, for the derivatives of the phosphorus acids X,P(O)OH, where X=F, C1, or H.283 The product obtained when X = Me and that from monothiodimethylphosphinate, i.e. Me,SbOP(S)Me,, on the other hand, appeared to be non-ionic, pointing to structures in which the phosphorus anion behaves as a bidentate group toward antimony. Dialkyl phos- phites can replace up to three of the chlorine atoms in ZrCl,, yielding products such as Zr[OP(O)(OR)RIgC1 and Zr[OP(0)(OR)R],C1,,284 while complexes of the type MO,Cl(O,PPh,), where M=Mo or W, were formed from the metal oxide chlorides M02C12 and diphenylphosphinic Reactions of triethyl or tri-n-butyl thiophosphate with metal chlorides have been investigated, in continu- ation of earlier work on the formation of metal complexes with (R0),P02 ligands.286 The products, which probably have polymeric structures, are of general formula [(RO),POS],M, where n = 2 for M = Fe" or V02+, n = 3 for Ti"', VI'', Cr"', or Fe"', and n = 4 for UIV or ThIV. An interesting transesterification reaction has been observed between triphenyl phosphate and aliphatic alcohols in the presence of an excess of caesium No reaction occurred in the absence of the fluoride, nor was exchange observed between alkyl phosphates and 280 J. C. Clardy, D. S. Milbrath, J. P. Springer, and J. G. Verkade, J. Amer. Chem. SOC., 1976,98, 623. 281 L. M. Loew, J. Amer. Chem. SOC., 1976, 98, 1630. *'' C. H. Clapp, A. Satterthwait, and F. H. Westheimer, J. Amer. Chem. SOC., 1975, 97, 6873. 283 B. Eberwein and J. Weidlein, 2. anorg. Chem., 1976, 420, 229. 284 D. M. Puri and A. Parkash, Indian J. Chem., 1975, 13, 384. 28s A. A. Kuznetsova, L. F. Yankina, Yu.G. Podzolko, I. A. Zakharova, and Yu. A. Buslaev, Russ. J. 286 C. M. Mikulski, L. L. Pytlewski, and N. M. Kalayannis, J. Inorg. Nuclear Chem., 1975, 37, 2411. 287 K. K. Ogilvie and S. L. Beaucage, J.C.S. Chem. Comm., 1976, 443. Inorg. Chem., 1975, 20, 891. Elements of Group V 215 alcohols, even when CsF was present. 1.r. and Raman spectra of four methyl dialkyl phosphates MeO(RO),PO have been interpreted.288 A trigonal-bipyramidal structure has been assigned to the phosphorane (65), which does not show the expected rapid pseudorotation in the n.m.r. the slow exchange rate is attributed to steric crowding by the two ortho-methyl groups. A new diphosphate structure (66) recently investigated by X-ray methods shows POP and OPO (endocyclic) angles of, respectively, 127.5 and 98.3°,290 while in the carbonyl diphosphonate (67) the anion has crystallographic two-fold symmetry, with the PO3 groups in a staggered conf~rmati on.~~’ (65) (66) (67) The problem of trigonal-bipyramidal vs. square-pyramidal co-ordination in five-co-ordinate phosphorus compounds has been considered in relation to struc- tural requirements of the l i gand~.~~’ Square-pyramidal structures occur when co-ordination involves five-membered rings which are either unsaturated or which contain highly electronegative groups attached to phosphorus, and can be related to decreased ring strain. Ring strain in the corresponding trigonal-bipyramidal structure has been calculated to be greater by some 3 4 kcal mol-’ as a result of the different apical and equatorial bond lengths inherent in the trigonal- bipyramidal structure. Basically trigonal-bipyramidal geometry is found in the structures of the phosphoranes (68)293 and (69),294 with oxygen atoms occupying the axial positions. The former molecule is, however, distorted, and has P-0 bond lengths of 1.700 and 1.763A. N.m.r. data over an extended temperature range have shown rapid intramolecular motion for members of a new series of caged polycyclic phosphoranes such as (70) which contain only six-membered On introduction of a five-membered ring, the exchange was inhibited, leading to activation energies of between 12 and 19 kcal mo1-l. ”* C. Garrigon-Lagrange and 0. Bouloussa, Compt. rend., 1976, 285 C, 15. 2u9 I. Szele, S. J. Kubisen jun., and F. H. Westheimer, J. Amer. Chem. SOC., 1976, 98, 3533. z9* J. S. Ricci, B. R. Davis, F. Ramirez, and J. F. Marecek, J. Amer. Chem. Soc., 1975, 97, 5457. 291 V. A. Uchtman and R. J. Jandacek, Acta Cryst., 1976, B32, 488. 292 R. R. Holmes, J. Amer. Chem. Soc., 1975, 97, 5379. 293 W. S. Sheldrick, Acta Cryst., 1976, It33 925. 294 D. Hellwinkel, W. Krapp, D. Schomburg, and W. S. Sheldrick, 2. Naturforsch., 1976, 31b, 948. B. S. Cafnpbell, N. J. De’ath, D. B. Denney, D. Z. Denney, I. S. Kipnis, and T. B. Min, J. Arner. Chem. SOC., 1976, 98, 2924. 295 216 Inorganic Chemistry of the Main-Group Elements High co-ordination numbers for phosphorus(v) can apparently be stabilized if the element is part of a spiro-di(benzodioxaphospho1e) system, as in (7 1).296 One (72) (7 1) (73) mole of pyridine has been shown to be added, giving a six-co-ordinate covalent compound, and only on addition of a second mole is the chlorine displaced, with formation of a cis-bis(pyridine) cation. An unusual opening of a phosphoryl linkage took place when phosphorous acid reacted with catechol in the presence of dicyclohexylcarbodi-imide, to produce the spiro-phosphorane (72).297 Under similar circumstances, POC13 gave the pentaoxyphosphorane (73), and, in the presence of base, the corresponding six-co-ordinate anion. As the P=O bond is normally considered to be inert, these reactions have important biological impli- cations. X- Ray Diffraction Studies. In addition to compounds mentioned later in the text, single-crystal X-ray studies have been carried out on the following compounds: NaH2P04,H20,298 CUK PO,,H~O,~~~ Ca,,Mn2H2(P0,)1, (manganese whitlock- ite),300 RbP02F2,301 Sr3(P309)2,7H20,302 Ba2Zn(P309)2. 10H20,303 Z~I ~( P ~O, ~) ~, 17- H20,304 Pb2P4012,4H20,305 LiNdP4012,306 and CdBa(P03)4.307 Lattice parame- ters have also been reported for M"M"'Ti(PO,), and M"M"'Sn(PO,), (MI' = Ca, Sr, or Ba; M"' = Cr or Fe)?" Gd4(P207)3,309 and LnP,O,, (Ln = La, Nd, or Er).310 Phase Studies. Phase systems that have been investigated during this period include (identified phases in square brackets): Na3P04-Zn3(P04)3 [3Na3P04,Zn3(P04)2, 3Na3P04,7Zn3(P0,)2, and NaZnP04],311 Na,P04- 296 A. Schmidpeter, T. von Criegern, and K. Blanck, Z. Naturforsch., 1976, 314 1058. 298 M. Catti and G. Ferraris, Acra Cryst., 1976, B32, 359. 299 M. Brunel-Laugt and I. Tordjman, Acta Cryst., 1976, B32, 203. 300 E. Kostiner and J . R. Rea, Acta Cryst., 1976, B32, 250. 301 W. Granier, J . Durand, L. Cot, and J . L. GalignC, Acta Cryst., 1975, B31, 2506. 302 I. Tordjman, A. Durif, and J . C. Guitei, Acta Cryst., 1976, B32, 205. 303 A. Durif, M. T. Averbuch-Pouchot, and J . C. Guitel, Acta Cryst., 1975, B31, 2680. '0-1 M. T. Averbuch-Pouchot, A. Durif, and J. C. Guitei, Acta Cryst., 1975, B31, 2482. 306 H. Koizumi, Acta Cryst., 1976, B32, 266. 307 M. T. Averbuch-Pouchot, A. Durif, and J . C. Guitel, Acta Cryst., 1975, B31, 2453. 308 A. Boudjada and R. Perret, Compt. rend., 1975, 281, C, 31; R. Perret and A. Boudjada, ibid., 1976, M. Gallagher, A. Munoz, G. Gence, and M. Koenig, J.C.S. Chem. Comm., 1976, 321. 297 H. Wortzala, Z. anorg. Chem., 1976, 421, 122. 305 282, C, 245. M. Kizilyalli, J. Znorg. Nuclear Chem., 1976, 38, 483. I. A. Bondar', L. P. Mezentseva, A. I. Domanskii, and M. M. Piryutko, Russ. J. Znorg. Chem., 1975, 20, 1448. A. W. Kolsi, A. Erb, and W. Freundlich, Compt. rend., 1976, 282, C, 575. 309 310 311 Elements of Group V 217 Cd3(P04), [NaCdPO,, Na,Cd,(PO,),, 3Na3P04,17Cd3(P04)2, and Na,Cd,- (P04)81?2 Zn3(P04)2-Zn3(V04)2 [Zn3Pl.50Vo.50081?13 Ba(PO3)2-NaPO3 “a,Ba- (PO,), and NaBa(PO3),I3l4 Na5P3010-A1C13-H20 [A1~(P3010)3,24H20],315 Cs,P4013-InC13-H20 [ CS~I ~~( P, O, ~) , , ~H~O and Cs31nP4013,~H20],316 and AgPO3-KPO3 [KAg(P03)2].317 Mono-, Di-, and Poly-phosphates. Dissociation of both phosphoric and arsenic acids in mixed aqueous solvents has been investigated by a potentiometric method.318 Concentrated phosphoric acid behaved as a reducing agent towards V205, leading to two new compounds that have been formulated as VO(P03)2 and v(Po3)3.319 The structure of a related vanadyl diphosphatomonosilicate VO(SiP208) showed the presence of V=O - - - V=O chains and Si(PO,),Si(PO,), units which were linked by oxygen atoms of the PO, group.32o Aspects of the cation-exchange properties of eight iron(Ir1) phosphate samples.,321 seven crystalline cerium(1v) and a number of zirconium phos- p h a t e ~~~~* ~~~ have been reported during the past year. In addition to this type of behaviour, the crystalline phosphates and arsenates M(HXO,),,nH,O (M = Zr, Si, Sn, or Cr; X = P or As) can take up certain neutral molecules to form a new class of intercalation compounds.325 With the zirconium phosphate, the intercalated species include DMSO, DMF, urea, piperidine, hexanol, and butyronitrile. of two members of a new series of heteropolymolybdates containing covalently bonded organic groups have been announced. The compounds which contain the anion [(RP)2M05021]4-, where R = H, Me, Et, Ph, or C2H4NH;, are stable in the pH range 2.5-5, and are not reduced to the usual molybdenum-blue species, Structures have also been given 062],9H20, the latter two consisting of two PM902806,2 units joined by a two-fold axis for M = Mo and a mirror plane for M = W.328 (See also references 382, 383, 453, and 454.) The sparingly soluble copper(I1) phosphates have been re-examined, confirming the existence of CuHPO,,H,O and CU,H(PO,)~,~H~O.”~~ An orthophosphate of protactinium(v) has recently been synthesized, the product PaO(H2P0,),,2H,O 312 A. W. Kolsi, A. Erb, and W. Freundlich, Compt. rend., 1976, 283, C, 119. 313 K. L. Idler and C. Calvo, Canad. J. Chem., 1975, 53, 3665. I. A. Tokman and G. A. Bukhalova, Russ. J. Inorg. Chem., 1975, 20, 601. 315 V. A. Lyutsko, N. F. Ermolenko, and L. I. Prodan, Russ. J. Inorg. Chem., 1976, 20, 792. G. V. Rodicheva, E. N. Deichman, 1. V. Tananaev, and Zh. K. Shaidarbekova, Russ. J. Inorg. Chem., 1975, 20, 1316. The isolation326 and crystal for Na3[PMo903i(H20)31,7H20, Na4H2[P2Moi80621,20H20, and (NH4)6[P2W18- 314 316 317 M. A. Savenkova, I. V. Mardirosova, and E. V. Poletaev, Russ. J. Inorg. Chem., 1975, 20, 1374. 318 I. Tossidis, Inorg. Nuclear Chem. Letters, 1976, 12, 1609. 319 B. C. Tofield, G. R. Crane, G. A. Pasteur, and R. C. Sherwood, J.C.S. Dalton, 1975, 1806. 320 C. E. Rice, W. R. Robinson, and B. C. Tofield, Inorg. Chem., 1976, 15, 345. 321 J. P. Rawat and P. S. Thind, Canad. J. Chem., 1976, 54, 1892. 322 R. G. Herman and A. Clearfield, J. Inorg. Nuclear Chem., 1976, 38, 853. 323 Y. Hasegawa, J. Inorg. Nuclear Chem., 1976, 38, 319; S. Yamanaka, Y. Horibe, and M. Tanaka, J. 324 A. Clearfield and R. A. Hunter, J. Inorg. Nuclear Chem., 1976, 38, 1085. 325 D. Behrendt, K. Beneke, and G. Lagaly, Angew. Chem. Internat. Edn., 1976, 15, 544. 326 W. Kwak, M. T. Pope, and T. F. Scully, J. Amer. Chem. Soc., 1975, 97, 5735. 327 J. K. Stalick and C. 0. Quicksall, Inorg. Chem., 1976, 15, 1577. 328 H. d’Amour, Acta Crysr., 1976, B32, 729. Inorg. Nuclear Chem., 1976, 38, 323. E. Hayek, P. Reinthaler, and J. Adamietz, Monatsh., 1976, 107, 557. 329 218 Inorganic Chemistry of the Main- Group Elements being converted successively into PaO(H,PO,),, PaO(P,O,), and (PaO)4(P,07)3 on heating.330 A re-examination of the thermolysis of QI -Na2H2P207 has produced evidence for modification of the course of the reaction, particularly by the addition of water.331 Owing probably to the hydrogen-bonding ability of the ammonium ion, the conformation of the P20;- ion in (NH.&P,o7 falls between the staggered and eclipsed conformations, thus differing from that in other M4P207 species.332 Pure manganese diphosphate has been obtained by metathesis between sodium diphos- phate and a molten MnK1 Interactions between tetra-, hexa-, and octa-metaphosphate anions and, inter alia, the alkali-metal cations have been investigated by conductivity and potentiometric methods, showing that, with the smaller cations, partial dehydration takes place during the formation of ion pairs.334 Bonds to Sulphur or Selenium.-Reviews have appeared on phosphorus sulphides and ~el eni des,~~ and on the chemistry of chiral thio- and seleno-derivatives of a range of phosphorus The structure of #?-P4Ss, shown with molecular dimensions in Figure 5, is a new form having similarities with the As4& structure, but differing considerably from that for the asymmetric a- i ~omer . ~~~ A complex multiplet, as expected for an AA'BB' system, has now been observed in the 31P n.m.r. spectrum of a-P4S31Z, pointing to the existence of structure (74) in solution, similar to that found for the solid The compound has also been found to behave as a unidentate ligand in reactions with metal carbonyl ~, ~~~ and to react with silver salts to replace the iodine atoms by C1, Br, CN, or NCS.340 4 . 2 9 5 - 2.1 25 Figure5 The (Reproduced structure of 0 -P,S, by permission from Acta Cryst., 1975, B31, 2738) M. F. Le Cloarec, J. M. Dartyge, S. Kovacevic, and R. Muxart, J. Znorg. Nuclear Chem., 1976, 38, 737. 330 331 A. de Sallier-Dupin, and P. Dugleux, Bull. SOC. chim. France, 1976, 417. 332 N. Middlemiss and C. Calvo, Canad. J. Chem., 1976, 54, 2025. 333 B. Durand, J. M. Plris, and P. Poix, Compt. rend., 1975, 281, C, 1007. 334 G. Kura and S. Ohashi, J. Inorg. Nuclear Chem., 1976, 38, 1151. 33s Y. Monteil and H. Vincent, Z. Naturforsch., 1976, 314 668. 336 M. Mikolajczyk and M. Leitloff, Rum. Chem. Rev., 1975, 44, 670. 337 A. M. Griffin and G. M. Sheldrick, Acta Cryst., 1975, B31, 2738. 338 M. Baudler, B. Kloth, D. Koch. and E. Tolls, 2. Nuturforsch., 1975, 30b, 340. 339 M. Baudler and H. Mozaffar-Zanganeh, Z. anorg. Chem., 1976, 423, 193. 340 E. Fluck, N. Yutronic S., and W. Haubold, Z. anorg. Chem., 1976, 420, 247. Elements of Group V 219 (74) Ternary compounds that have been isolated and investigated during the period under review include CoMS and CoMSe ( M=P, As, or Sb),342 and Zn,-, Fe, PS3.343 The reaction between P2S5 and urea has been shown to give mainly ammonium PP-dithiophosphacyanurate and a small amount of a 1 : 1 adduct of this com- pound with Crystallographic investigations of both the ammonium and thallium(1) salts show the presence of cyclic anions (75) with a shallow boat conformation, linked together by N-H - * * 0 hydrogen Although PzS5 and alkyl halides did not react even at elevated temperatures, the reaction was promoted, probably via the formation of carbonium ions, on addition of aluminium tri ~hl ori de.~~~ Small amounts of tetrathioates S=P(SR), were obtained with primary and secondary halides, but, unexpectedly, 40-45% yields of the chlorotrithioates (RS),P(S)CI also A novel anion that has been formulated as [Pl2Sl2Nl4I6- has been synthesized by a reaction between P,S, and molten potassium thiocyanate, and has been crystallized from The structure shown in Figure 6 consists of twelve I A , Figure 6 The structure of the [Pl2NI4Sl2l6- union (Reproduced by permission from 2. Naturforsch., 1976, 31b, 419) 341 R. Henry, H. Nahigian, J. Steger, and A. Wold, Inorg. Chem., 1975, 14, 2912. 342 R. Henry, J. Steger, H. Nahigian, and A. Wold, Inorg. Chern., 1975, 14, 2915. J.-P. Odile, J. Steger, and A. Wold, Inorg. Chem., 1975, 14, 2400. 344 B. Aurivillius and C. StPlhandske, Actu Chem. Scand. ( A) , 1975, 29, 717, 345 J.-E. Andersson and C. Stllhandske, Acru Cryst., 1976, B32, 587. 346 I. V. Murav’ev and I. S. Fedorovich, J. Gen. Chem. (U.S.S.R.), 1975, 45, 1711. 347 E. muck, M. Lang, F. Horn, E. Hadicke, and G. M. Sheldrick, 2. Naturforsch., 1976, 31b, 419. 343 220 Inorganic Chemistry of the Main-Group Elements shared P3N3 rings in a dodecahedra1 arrangement, with a sulphur atom attached at the periphery to each phosphorus atom. Conversion of the isomeric l-chloro- phospholen 1-oxides (76a) and (77a) into the corresponding sulphides (76b) and (77b) occurred in refluxing with P2S5 in toluene.348 (76) a, X =O (77) a , X=O b, X= S b, X=S Infrared spectra for the tris( 0-ethylxanthates) of phosphorus, arsenic, an- timony, and bismuth showed a monotonic decrease in v(CO), attributed to a slight opening of the ligand bite with increase in the size of the central atom;349 the 31P n.m.r. chemical shifts for the four-co-ordinate compounds (EtO),-,Et,PS and [(EtO),-,Et,PSEt]’, where n = 0-3, have been discussed in relation to the degree of s~bsti tuti on.~~’ The establishment of the red phosphorus-selenium phase diagram by d.t.a. and X-ray methods confirmed the existence of P4Selo and three forms of P4Se3, and additionally showed the formation of two forms of the new binary compound P4Se4.351 Addition of bromine to triphenylphosphine selenide occurred with oxidation of selenium and the formation of the compound Ph,PSeBr, as a monomeric n~n-el ectrol yte.~~~ Some 00-dialkyl alkylphosphoramidoselenoates, (R10),P(Se)NHR2, have been isolated, being prepared by methods involving either amination of the corresponding chloride (RIO),P(Se)Cl or the addition of selenium to the appropriate phosphorus(n1) 3 Arsenic Arsenides.-Some indications of the complexity of binary arsenide structures are apparent from recent X-ray investigations. In the new intermetallic compound Ca,As,, As4 and As, chains are present in a 1:l ratio, with As-As distances ranging between 2.47 and 2.5881.354 As:- units occur in the simple arsenide CaAs, which has an anti-NiAs structure, and here the As-As separation is 2.563 A.355 The ternary arsenides Ca5Ga2AS6 and Ca,Ga3As, have also been the structure of the former containing layers of Ca-As octahedra and tetrahed~a.~~’ As expected from valence considerations, As2 units are present 348 K. Moedritzer. Z. Naturforsch., 1976, 314 709. 349 G. Winter, Austral. J. Chem., 1976, 29, 559. 350 R. Radeglia, J. Schulze, and H. Teichmann, Z. Chem., 1975, 15, 357. ’” Y. Monteil and H. Vincent, J. Inorg. Nuclear Chem., 1975, 37, 2053. ’” D. J. Williams and K. J. Wynne, Inorg. Chem., 1976, 15, 1449. ”’ L. K. Nikonorova, N. P. Grechkin, and I. A. Nuretdinov, J. Gen. Chem. (U.S.S.R.), 1975, 45, 995. 354 K. Deller and B. Eisenmann, Z. Natwrforsch., 1976, 31b, 1023. ’” P. L‘Haridon, J. Guyader, and M. Hamon, Rev. Chim. mintrale, 1976, 13, 185. 3s6 P. Verdier, M. Maunaye, R. Marchand, and J. Lang, Compt. rend., 1975, 281, C, 457. ’” P. Verdier, P. L’Haridon, M. Maunaye, and Y. Laurent, Acta Cryst., 1976, B32, 726. Elements of Group V 221 (separation 2.489 A), and the formulation is best represented as C~:’G~:”AS~’(AS,)’~. Two new bromine-containing species Ca,AsBr and Ca,AsBr, have been isolated from high-temperature reactions between mixtures of calcium, arsenic, and calcium Crystal structures have been reported for the p and y modifications of V,As3 and CT,AS,~,~ and for Nb3A~.360 Complete solid solubility has been found in the Crp- CrA~,~~l C~A S- COA S, ~~~ and F~As-COAS~~, systems, with the phosphorus and arsenic atoms randomly arranged in a MnP-type structure. Arsenic and bismuth vapours, at elevated temperatures, produce insertion-type bronze phases on interaction with W0,.363 Bonds to Carbon.-Although species such as PhA-AsPh have not been isolated at room temperature, this compound has been stabilized in the complex P~,AS,[CT(CO),]~.~~~ An X-ray structure showed co-ordination from the two arsenic atoms to Cr(CO), groups, with the third Cr(CO), group attached via .rr-interaction from the As=As centre. Compound (78), 4-hydroxyarsabenzene, has been prepared.365 The .shorter Si-As distance (2.334A) in Me,AsSiF, than in A s( S~H~) ~ is considered to be due to inductive effects, and is not a result of n- b~ndi ng. ~~~ An azarsasilolidine (79) has been prepared by the reaction of Me,SiCl, and the dilithium salt LiAsPhCH,CH,NEtLi, and similar ring-closure reactions can be achieved when the silicon dihalide is replaced by PhBCl,, Et2SnC1,, MePCl,, or MeA~cl ,.~~’ nu Ph Et (78) (79) Recent experiments indicate that Ph,As is a stronger base than Ph,AsH, and that the Lewis acidity for some representative boranes decreases in the order BBr, > BH3 > MeBBr, > Me2BBr.368 The complexity of the arsino-boranes R~AsBR; formed from such reactions varies with the nature of the attached groups, leading to a monomeric structure for R:AsB(NMe,), but trimeric struc- tures for both Me,BAsMe, and M ~, A s B B ~M ~. ~~~ Alkyl- or aryl-dichloroarsines and malonic esters have been found to yield 1,3- diarsacyclobutane derivatives (SO), in contrast to the 1,2-diphosphacyclopentenes 3s8 C. Hadenfeldt, Z. Nuturforsch., 1976, 31b, 408. 3s9 R. Berger, Acra Chem. Scund. ( A) , 1976, 30, 363. 360 R. M. Waterstrat, K. Yvon, H. D. Flack, and E. ParthB, Acfu Cr y s f . , 1975, B31, 2765. K. Selte, H. Hjersing, A. Kjekshus, A. F. Andresen, and P. Fischer, Acru Chem. Scand. ( A) , 1975, 29, 695. K. Selte, A. Kjekshus, S. Aaby, and A. F. Andresen, Actu Chem. Scand. ( A) , 1975, 29, 810. M. Parmentier and C. Gleitzer, Compr. rend., 1975, 281, C, 819. G. Huttner, H.-G. Schmid, A. Frank, and 0. Orama, Angew. Chem. Inrernaf. Edn., 1976,15,234. G. Markl, H. Baier, and S. Heinrich, Angew. Chem. Infemar. Edn., 1975, 14, 710. H. Oberhammer and R. Demuth, J.C.S. Dalton, 1976, 1121. 361 362 363 364 365 366 367 A. Tnchach and J. Heinicke, 2. Chem., 1976, 16, 278. 368 R. Goetze and H. Noth, 2. Nururforsch., 1975, 30b, 343. 369 R. Goetze and H. Noth, 2. Narurforsch., 1975, 30b, 875. 222 Inorganic Chemistry of the Main- Group Elements obtained in the corresponding phosphorus The six-membered ring in the arsonium nitrate (81) has a chair conformation, with a 1,4-transannular As - - - 0 distance of 3.10 R' Me /CH-cH2 Ph \/ \c/ \+ / ~ 2 0 , ~ As C0,R2 R202C ' 'As/ \C02RZ R' 0 As NO; CH-CH, ' \Ph \ Me (80) (8 1) The He (I) p.e. spectra for the ylides Me3As=CH2, Me3As=CHSiMe3, and Me,As=C(SiMe,), have been compared with data for similar phosphorus com- pounds and the results of semi-empirical M.O. calculations.372 Bonds to Halogens.-The elusive arsenic pentachloride has been isolated as the product from U.V. irradiation of a mixture of AsCl, and chlorine at low temperature^.^^^Results from conventional analysis support this formulation for the pale yellow solid, melting at -50°C with partial decomposition, and the Raman data point to a trigonal-bipyramidal structure but no great weakness in the As-C1 bond strengths. The high 4s-4p,d promotion energy is thought to be the most significant factor contributing to the instability. Some ,'Cl n.q.r. data for the alkyl- and alkoxy-chloro-arsines R,AsCl,-, and (RO),AsCl,-, can be analysed in terms of the electronegativity of the arsenic atom, and a comparison of the two sets of data provides strong evidence for back- co-ordination from oxygen to arsenic.374 Two new phosphato-arsines have been synthesized when methyl halide is lost in the reaction of MeAsI, or PhAsCl, with trimethyl ph~sphi te;,~~ spectroscopic properties agree with the formulation RAs[P(O)(OMe),], (R = Me or Ph). Substitution of PhAsI, for the chloride, however, led to the isolation of PhAsIAsIPh when a 1 : 1 mole ratio was used, but to the diphosphine-diarsine (82) with two moles of trimethyl phosphite. Ph P(O)(OMe), \ / (MeO),(O)P /As-As 'Ph (82) A high-temperature Raman spectroscopic study of the As-I system has pro- vided evidence for the interaction of gaseous AsI, with solid arsenic at 300 "C, in accordance with equations (22) and (23).376 370 H.-J. Padberg and G. Bergerhoff, Angew. Chem. Internat. Edn., 1976, 15, 56. 371 M. Drager, 2. anorg. Chem., 1976, 421, 174. 372 K.-H. A. Ostoja Starzewski, W. Richter, and H. Schmidbaur, Chem. Ber., 1976, 109, 473. 374 G. Jugie, J. A. S. Smith, M. Durand, and J.-P. Laurent, Compt. rend., 1976, 283, C, 191. 375 K. M. Abraham and J. R. van Wazer, Inorg. Chem., 1976, 15, 857. 376 R. Hillel, J. Bonix, and R. Favre, Bull. SOC. chim. France, 1975, 2458. K. Seppelt, Angew. Chem. Internat. Edn., 1976, 15, 377. 373 Elements of Group V 223 Bonds to Nitrogen.-Cleavage of the arsenic-nitrogen bond in a variety of amino-arsines by poly-alcohols has provided a ready route to a large number of arsolan-type specie^.^^^,^^' Among the amino-arsines employed were As(NMe2)3, MeAs(NMe,),, and Me,AsNMe2; products such as (83) and (84) were isolated. Transamination reactions between (85) and secondary amines have greatly in- creased the number of compounds in this category that have been made3" (see also refs. 386-388). /CHz-o \ MeC-CH,-0-As / CH2-0 \ 0-CH2 \ (83) (84) Me,NAs l0-r Me, i - f. TMe2 RN NR c1 (86) M = As or Sb \M' Me2NAs ( 85) New heterocycles (86) containing either arsenic or antimony were the products when 1,2-di(alkylamino)disilanes reacted with the Group V tri~hlorides.~~' Bonds to Oxygen.-A compound with the stoicheiometry As,03,S03, obtained from solutions of As203 in concentrated sulphuric acid, has been, shown to contain AsOl' chains (As-0 1.80 and 1.74& LOAsO94") linked together by tetrahedral SO, groups381 (see also ref. 451). Structures for the 1 : 3 arsenomolybdates and [(P~As),Mo,O,,]~- in solution have been established by 170 n.m.r. studies, showing an Mo602, ring of edge-sharing Moo6 octahedra that is capped above and below by RAsO, tripods (R=Ph or O).382 A new series of 19-tungsto- dimetallo-diarsenate(n1) anions with the formula [A&nZ2W19067(OHx )2114-2x)-, where Z = Mn", Co", Ni", Cu", Zn", Mn"', Fe"', Ga"', or V'", has been isolated, forming part of the general As,W,,-,Z, system of acids in which n = 1-3383 (see also ref. 393). The unknown compound tri-t-butyl arsenate has now been produced by trans- esterification of trimethyl arsenate with a large excess of dry t-butyl but neither transesterification nor other conventional approaches gave the inter- esting, sterically hindered arsenite (P~,CO),AS.~~~ The method successfully used was the reaction between arsenic trichloride and Ph,CONa in ether. 377 W. J. Ruhl and F. Kober, 2. Naturforsch., 1976, 31b, 190, 307. 378 F. Kober and W. J. Ruhl, Z. anorg./Chem., 1976, 420, 74. 379 0. Adler and F. Kober, Z. Naturforsch., 1976, 314 304. U. Wannagat and M. Schlingmann, Z. anorg. Chem., 1976, 424, 87. 381 R. Mercier, Rev. Chim. mintrale, 1975, 12, 508. 382 M. Filowitz and E. W. G. Klemperer, J.C.S. Chem. Comm., 1976, 233. 384 D. Hass, 2. Chem., 1975, 15, 488. 385 D. Hass and B. Jablonka, Z. Chem., 1976, 16, 374. 380 C. Tourn6 and G. TournB, Compt. rend., 1975, 281, C, 933. 383 224 Inorganic Chemistry of the Main- Group Elements Reactions of the oxathia- ( 85) , and di-oxa- or -thia-arsolans (87) with alcohols or thiols lead to replacement of the dimethylamino-group by OR or SR groups;386 similarly, the chlorine atom in the oxazarsolidine (88) can be replaced by alcohols, thiols, or ami ne~.~" Oximes opened the cyclic ester system of arsolans and arsepins when the arsenic atom also carried a methyl group, but, in the case of substitution with NMe,, OMe, or C1, this group was replaced by oxime, and the ester ring remained intact.388 N.m.r. data for a number of newly prepared cyclic arsenite systems have been interpreted in terms of rapidly interconverting twist and envelope conformati on~.~~~ Me,NAs 7-r clAs/o-r N-CH, \X--CH, \ Me (88) (87) X=O or S Chloranil oxidized a variety of methylarsenic(rr1) esters, amides, or cyclic thioesters, products such as (89), for example, being obtained from a dithioester of methylarsonous acid.390 The analogous reaction with 2-iodo-l,3,2-dihetero- arsolans, however, proceeded with simultaneous cleavage of the As-I bond and formation of the spirocyclic arsenic(v) compound (90).3g1 The six-co-ordinate arsenic(v) anions (91) were produced by addition of an alcohol or phenol to an arsolan in the presence of triethylamine, the latter abstracting a proton and forming the required (90) X= Y= Oo r S (91) Potentiometric measurements in the H'-MoO~--HAsO~- system have been explained on the basis of the formation of colourless species in the series HS(Mo04)5(HA~04)2 and H,,(MoO~)~(HASO~)~ ( n = 10-12) and yellow com- plexes of the form H,,(MoO,),(HAsO,) ( n = 14-17).393 The exchange between .386 0. Adler and F. Kober, Z. anorg. Chem., 1976, 420, 109. 387 0. Adler and F. Kober, 2. Naturforsch., 1976, 31b, 246. 388 J. Kaufmann and F. Kober, 2. anorg. Chem., 1976, 420, 177. 389 D. W. Aksnes, F. A. Amer, and K. Bergesen, AcraChem. Scand. ( A) , 1976, 30, 109. 390 J. GOtz and M. Wieber, 2. anorg. Chem., 1976, 423, 235, 239. 391 M. Wieber and J. Gotz, Z. anorg. Chem., 1976, 424, 56. 392 M. Wieber and T. Mallon, 2. anorg. Chem., 1976, 424, 27. 393 L. Petterson, Acf a Chem. Scand. ( A) , 1975, 29, 677. Elements of Group V 225 alkylarsenates and alcohols, determined from 'H n.m.r. line-broadening experi- ments, is fast, in contrast to the behaviour of the corresponding phosphorus system?, a five-co-ordinate transition state has been postulated in which the degree of bond breaking depends on the size of the alkyl group. The degree of substitution of Na' by Ag' in the double arsenate M'CaAs04 has been followed by vibrational spectroscopy and by determining the changes in the dimensions of the unit cell, showing the effect of increased covalence in the silver The hydrated arsenate Ti(HAs04),,H20 has been obtained from TiCl, and As205 in hydrochloric acid, and its thermal decomposition to give TiAs,O,, Ti,(AsO,),, and (TiO),As,O, has been The preparation and ion-exchange properties of iron(II1) arsenate have also been examined, and it has been shown that the most stable form results from homogeneous precipita- t i ~n. ~~' Mixtures of arsenic pentoxide and manganese carbonate, on heating to 600 "C, gave the diarsenate M~,As,O,.~~' With the data for Na,As03S,7H,0 reported here,399 all members of the series AsO,-,S~- have been investigated structurally. The anion is tetrahedral, with mean values of 1.67 and 2.14 A for the As-0 and As-S distances. Bonds to Sulphur or Selenium.-Rapid cooling of a 1 : 1 mixture of arsenic and sulphur from ca. 550 "C led to the isolation of a new isomeric form of As,S, with a structure derived from an As, tetrahedron, as shown in Figure 7.,0° Mean As-S and As-As distances are 2.244 and 2.535 A, respectively, while values for the AsAsAs, AsAsS, SASS, and AsSAs angles are 83.2, 95.8, 101.2, and 105.2", Figure 7 The structure of the new As,S, modification (Reproduced by permission from 2. anorg. Chem., 1976, 419, 176) 394 39s 396 397 398 399 400 P. J. White, M. J. Kaus, J. 0. Edwards, and P. H. Rieger, J.C.S. Chem. Comm., 1976, 429. M. Th. Paques-Ledent, J. Inorg. Nuclear Chem., 1976, 38, 215. N. G. Chernorukov and M. I. Zhuk, Russ. J. Inorg. Chem., 1975, 20, 1413. J. P. Rawat and J. P. Singh, Canad. J. Chem., 1976, 54, 2534. I. L. Botto, E. J. Baran, P. J. Aymonino, J. C. Pedregosa, and G. F. Puelles, Monafsh., 1975, 106, 1559. M. Palazzi, Acta Cr y s t . , 1976, B32, 516. A. Kutoglu, 2. morg. Chem., 1976, 419, 176. 226 Inorganic Chemistry of the Main - Group Elements respectively. The structure of As(S,CNEt,), is isomorphous with those of the Rh"' and MnlI1 compounds, but here the ASS, core is distorted toward C, This is a consequence of the stereochemical activity of the lone pair, and leads to two different As-S distances (2.35 and 2.84A); the two C-S distances in the ligands are also widely different (1.68 and 1.76 A). The As,S,-Na,S system shows evidence of formation of NaAsS, and Na3AsS3,,02 while in the Ge-As-Se system the ternary species GeAsSe and GeAs,Se have been identified.,', 4 Antimony Antimony and Antimonides.-There appears to be little correlation between the formal oxidation state of antimony and the 3d( 3/ 2, 5/ 2) binding energies from recent X-ray p.e. spectral data,,', but within a given series the binding energy appears to be a function of the electronegativity of the ligand. A new method for preparing stable homo-polyatomic anions of antimony, bismuth, tin, and lead has been announced with circumvents the problem of decomposition to the parent alloy.405 The method depends on the ability of 2,2,2-crypt to complex with the alkali-metal cation and so prevent electron transfer from the polyatomic anion. Ethylenediamine is the usual solvent, and compounds such as [Na(crypt)+],Sb;- and [Na(crypt)'],Pb:- have been isolated; the curious end-capped trigonal-prismatic structure that was identified by X-ray methods in the former compound is shown in Figure 8. Crystal structures for Cal l Sbl y (and the bismuth analogue) and SrSb,407 have shown the presence of Sb, rings and Sb, units, in addition to single Sb atoms in the former, but zig-zag chains of antimony atoms (Sb-Sb 2.895-2.919 A) in the latter. Recent evidence Figure 8 The structure of the Sb;- ion in the salt [Na(crypt)+],Sb:- (Reproduced by permission from J. Amer. Chern. SOC., 1975, 97, 6267) 4n1 C. L. Raston and A. H. White, J.C.S. Dalton, 1975, 2425. 402 N. I. Kopylov and S. M. Minkevich, Rum. J. Znorg. Chem., 1975, 20, 1744. 4n3 K. E. Pachali, J. Ruska, and H. Thurn, Znorg. Chem., 1976, 15, 991. 404 T. Birchall, J. A. Connor, and I. H. Hillier, J.C.S. Dalton, 1975, 2003. 4n5 J. D. Corbett, D. E. Adolphson, D. J. Merryman, P. A. Edwards, and F. J. Armatis, J. Amer. Chem. 406 K. Deller and B. Eisenmann, 2. Naturforsch., 1976, 31b, 29. 407 K. Deller and B. Eisenmann, 2. Naturforsch., 1976, 31b, 1146. SOC., 1975, 97, 6267. Elements of Group V 227 suggests that the germanium atoms in the clathrates Ge38M814 (M = As or Sb) can be substituted on treatment with, respectively, GaAs or GaSb.408 With the latter, the product is a new clathrate Ga14(GaSb),,Sb814, for which a structure has been obtained by studying a single crystal. Bonds to Carbon.-Treatment of phenylstibine with alkyl-lithium compounds gave, in a complicated reaction, either (PhSb), and hydrogen or mixtures contain- ing, for example, PhSbLi, and PhSbBuLi, depending on the conditions.409 With sodium in liquid ammonia, the product was PhSbNa,, which reacted with 1,4-di- chlorobutane to give the stibolan (92) and with bis(a -chlorobenzylidene)- hydrazine to give a distibine, perhaps with structure (93). The material known as 'phenylantimony' has now been obtained in a crystalline form when either styrene or phenylacetylene reacts with phenyl~tibine.~" The product, which has the formula (PhSb)6,PhH, is orange-yellow, and it reacts with sodium in liquid ammonia to give PhNaSbSbNaPh in addition to PhSbNa,. PhSb lCH2--(iH, I CH2-CH2 (92) \ Two new dinuclear antimony(v) compounds containing a Sb-X-Sb bridge (X=CN or F) have been prepared by treatment of Me,SbCI, with either Me4NCN or the An octahedral arrangement around each antimony atom has been suggested, on the basis of the vibrational spectra. Thioacetates Ph3Sb(02CCH2SR) are the products when triphenylantimony dibromide reacts with the requisite acetic acid and the monomeric chelate (94) has been obtained by displacement of a methyl group from SbMe, by di a~etami de.~~~ Me I (94) I2lSb Mossbauer data for the RSbX; and R,SbX, anions, where R = Me or Ph and X=F, C1, Br, N3, or NCS, have been analysed and compared with data for corresponding tin The data point to a trans-arrangement of the R 408 H. G. von Schnering and H. Menke, Z. anorg. Chem., 1976, 424, 108. 409 K. Issleib and A. Balszuweit, Z. anorg. Chem., 1975, 418, 158. 410 K. Issleib and A. Balszuweit, 2. anorg. Chern., 1976, 419, 87. 411 K. Dehnicke and H.-G. Nadler, Z. anorg. Chem., 1975, 418, 229. 413 B. Eberwein, F. Sille, and J. Weidlein, Z. Naturforsch., 1976, 31b, 689. 414 N. Bertazzi. T. C. Gibb, and N. N. Greenwood, J.C.S. Dalton, 1976, 1153. A. Ouchi, H. Honda, and S. Kitazima, J. Inorg. Nuclear Chem., 1975, 37, 2559. 412 228 Inorganic Chemistry of the Main- Group Elements groups in R2SbX, and a similar trans structure, with bridging chlorine atoms, for Me2SbC13. A method has been devised for calculating orbital populations for antimony(v) compounds from Mossbauer data.415 Bonds to Halogens.-Antimony (111) Compounds. Neutral complexes of SbF, are rare, but compounds such as SbF3,2L (L=Ph,AsO or an amine oxide) and SbF3,L,H20 (L = imidazole or o-tolidine) have recently been isolated from solu- tions in Structurally, the monohydrate of SbF3,(4-methoxypyridine N-oxide), is basically square-pyramidal, with a mirror plane passing through the rn01ecule."~~The water interacts only weakly with a fluorine atom, and the lone pair on antimony can be considered as occupying the sixth octahedral position. A number of salts containing the SbF3X- anion (X=Cl or Br) have been prepared and investigated by single-crystal and spectroscopic rnethod~.~" A full X-ray determination for KSbF,Cl showed the co-ordination sphere of antimony to contain three fluorine atoms (at 1.935, 1.948, and 1.956A), three chlorine atoms (at 3.087, 3.107, and 3.159A), and a lone pair of electrons in the form of a monocapped The hydrated tetrafluoroantimonates M(SbF4),,6H20, for M = Co, Ni, Cu, or Zn, have also been isolated,42' and the structure of KSb4F,, has been determined.421 The latter, which contains tetra- hedral F(SbFJ 4 units linked into a three-dimensional network, presents an interesting bonding problem; as found for SbF,Cl-, the antimony atom here is also in seven-fold co-ordination. Further members of the [(SbF,),(SbF,)r- series of anions, e.g. Sb,R;, Sb4F:;, and Sb,F:y, have been prepared from aqueous hydrogen fluoride solutions containing SbF3 and KSbF4,422 while the guanidinium been observed to exist in the equilibrium phase diagram, and they have been isolated.423 A study of microwave spectra for six isotopically substituted SbC13 molecules led to values of 2.322A and 97.19' for the bond distance and angle, respec- t i ~el y . ~~~ A number of 2 : 1 complexes between SbCl, and aromatic hydrocarbons, including durene, hexamethylbenzene, naphthalene, biphenyl, and 2,3-dimethyl- naphthalene, have been identified in phase The structure of a com- pound of this type, 2SbC13,p-xylene, consists of alternate layers of SbCl, and p-xylene molecules; the distance between the antimony atom and the plane of the xylene molecule is 3.09A, and although the dipoles of the SbC1, are orientated antiparallel, formal halogen bridging does not occur.426 Antimony(II1) and bismuth(m) halides form complexes with one or three salts [(NHACI2SbF,, [(NHACISbF4, [(NH2)3CISb2F7, and [(NH~)~CI S~~FI , have 415 L. H. Bowen and G. G. Long, Inorg. Chem., 1976, 15, 1039. 416 F. Petillon, J. E. Guerchais, J. C. Dewan, and A. J. Edwards, J. Inorg. Nuclear Chem., 1976,38, 167. 417 J. C. Dewan, A. J. Edwards, J. E. Guerchais, and F. Petillon, J.C.S. Dalton, 1975, 2295. B. Ducourant, B. Bonnet, R. Fourcade, and G. Mascherpa, Bull. SOC. chim. France, 1976, 1089; Compt. rend., 1976, 283, C, 203. B. Ducourant, R. Fourcade, E. Philipot, and G. Mascherpa, Rev. Chim. minerale, 1975, 12, 485. N. Habibi, B. Ducourant, J.-F. Herzog, and R. Fourcade, Bull. SOC. chim. France, 1976. 77. B. Ducourant, R. Fourcade, E. Philipot, and G. Mascherpa, Rev. Chim. minirale, 1975, 12, 553. P. Djahanguiri, B. Bonnet, R. Fourcade, and G. Mascherpa, Bull. SOC. chim. France, 1976, 377. 418 419 420 42 1 422 B. Ducourant and R. Fourcade, Compt. rend., 1976, 282, C, 741. 424 G. Cazzoli and W. Caminati, J. Mol. Spectroscopy, 1976, 62, 1. 425 H.-H. Perkampus and E. Schonberger, Z. Narurforsch., 1976, 31b, 475. 426 R. Hulme and D. J. E. Mullen, J. C. S. Dalton, 1976, 802. 423 Elements of Group V 229 molecules of piperidine or pi pera~i ne?~~ while with methyl- and dimethyl- acetamide the major species formed by reaction with SbC13 in solution is the 1 : 1 complex.428 In the case of benzoin as a ligand, the MC13 (M=As, Sb, or Bi) and SbX5 (X=F or Cl) products were formulated as (95) and (96), X X 0-7-Ph F / \ C1 0- -Ph H H (95) ( 94) The synthesis of bromoantimonate(II1) species from SbBr, and amine hydro- bromides, both in the absence of solvent and in hydrobromic acid solution, has been rein~estigated.~~' The structure of pyH' SbBri is similar to that of the corresponding chloride, containing infinite chains of antimony atoms linked by bromine atoms in a distorted octahedral envi r~nment.~~' The Sb-Br distances are 2.563 and 2.795 8, for the non-bridging and bridging atoms, respectively, and the octahedral arrangement is completed by an Sb-Br distance of 3.2308,. Metal carbonyls and antimony tribromide react to give new compounds formu- lated as, for example, (w-Cp)(CO),MSbBr, and (w-Cp)(CO),MSbBrM'(CO),(?r- Cp), where M = M' = Mo or W and M' = Fe.432 Esterification of t-butylantimony dibrornide with dihydric alcohols gave the expected dioxastiboles and dioxastib- 01ans.~~~ Antimony (v) Compounds. The nature of the strongly methylating species present in solutions of methyl fluoride and antimony pentafluoride in sulphur dioxide has been identified as [MeO==S=O]' Sb2Fyl,434*435 but in S02F2 solution the 19F n.m.r. data strongly suggest the formation of a simple donor-acceptor complex The 1 : 1 adduct IF5,SbF5 is well characterized, and crystallographic data are now available to show that the 1 :2 complex can be formulated as IF: Sb2FT1, but there is a strong fluorine-bridging interaction to the iodine Defini- tive evidence is also available on the structure of the mixed halide SbC1,F2 obtained from SbC14F and SbF5 in sulphur The compound is a tetramer, with cis-fluorine bridges, the bridging and non-bridging distances being 2.07 and 1.92 .$, respectively. The 1 : 1 addition compound between methanol and antimony pentachloride will react with further alcohol to produce the compounds SbCl,,nMeOH ( n = 2- 4).438 1.r. data point to hydrogen-bridged structures such as (97) for the products 427 G. Marcotrigiano, L. Menabue, and G. E. Pellacani, J. Mol. Structure, 1976, 30, 85. 429 K. C. Malhotra and S. C. Chaudhry, Indian J. Chem., 1975, 13, 935. 430 N. K. Jha and S. S. A. Rizvi, J, lnorg. Nuclear Chem., 1976, 38, 401. 431 P. W. Dehaven and R. A. Jacobson, Cryst. Struct. Comm., 1976, 5, 31. 432 W. Malisch and P. Panster, 2. Naturforsch., 1975, 30b, 229. 433 M. Wieber and N. Baumann, 2. anorg. Chem., 1975, 418, 167. 434 J.-Y. Calves and R. J. Gillespie, J.C.S. Chem. Comm., 1976, 506. 43s P. E. Peterson, R. Brockington, and D. W. Vidrine, J. Amer. Chem. SOC., 1976, 98, 2660; G. A. Olah, D. J. Donovan, and H. C. Lin, ibid., p. 2662. 436 A. J. Edwards and P. Taylor, J.C.S. Dalton, 1975, 2174. 437 J. G. Ballard, T. Birchall, and D. R. Slim, J.C.S. Chem. Comm., 1976, 653. 438 R. Ortwein and A. Schmidt, 2. anorg. Chem., 1976, 420, 240. M. van Cauteren and Th. Zeegers-Huyskens, lnorg. Nuclear Chem. Letters, 1976, 12, 323. 428 230 with n = 2 and 3, but the ionic formulation [H’(MeOH),]’[SbCl,OMe]- is prefer- red for that with n = 4. The formation of a trihydrate that melts incongruently at 32.6 “C in the SbC1,-H20 system has been Vibrational spectra for adducts of SbCl, with DMF, Me,PO, OPCl,, OSeCl,, OSC12,440 and have been assigned, and from the latter an i.r. criterion has been proposed for distinguishing between S- and 0-bonded sulphur dioxide. Inorganic Chemistry of the Main-Group Elements R / \ /R C1,Sb + 0 H* * ‘0, H (97) Dialkyl selenites, on reaction with SbC15, readily gave the monoalkoxy- derivative SbCl,OR, with SeOCl, as the and the acceptor proper- ties of such mono-alkoxy species, where R = Me, Et, C2H4C1Y CH2CF3,444 or CH2CC13,445 have been investigated. A dimeric form of SbC1,NCO (98), stable at low temperatures, has been isolated from a reaction between KSbC15NC0 and SbCl, in solution in liquid SO2, but above room temperature the rearrangement to an s-triazene derivative (99) has been confirmed by an X-ray A new heterocycle (100) has been synthesized by the action of water on the formamidinium salt [ClC(O)N- MeCClNMeC(O)Cl]’ SbCl,, which is the initial product when SbCl, and methyl isocyanate are refluxed in carbon tetra~hloride.~~’ (99) An ionic isomeric form of dimethylantimony trichloride, i.e. [Me,Sb][SbCl,], has been identified and characterized by vibrational spectroscopy as the product of alkylation of antimony pentachloride with Me21nC1.448 Analogous reactions 43q G. Picotin and P. Vitse, Bull. SOC. chim. France, 1976, 745. M. Burgard, J.-P. Brunette, and M. J. F. Leroy, Inorg. Chem., 1976, 15, 1225. 441 D. M. Byler and D. F. Shriver, Inorg. Chem., 1976, 15, 32. 442 R. C. Paul, K. K. Bhasin, and R. D. Sharma, Indian J. Chem., 1975, 13, 723. 443 R. C. Paul, H. Madan, and S. L. Chadha, Indian J. Chem., 1975, 13, 1188. 444 R. C. Paul, P. Sharma, L. Subbiah, H. Singh, and S. L. Chadha, J. Inorg. Nuclear Chem., 1976, 38, 440 169. R. C. Paul, D. K. Airon, and S. L. Chadha, Indian J. Chem., 1976, 14A, 51. 446 U. Miiller, 2. anorg. Chem., 1976, 422, 134, 141. 447 G. Birke, H. P. Latscha, and A. Schmidt, Z. anorg. Chem., 1976, 424, 287. 448 H. J. Widler, H.-D. Hausen, and J . Weidlein, Z. Naturforsch., 1975, 30b, 645. Elements of Group V 23 1 with Me,SbCl, and Me,AsCl, led to [Me,Sb][MeInCl,] and [Me4As][MeInC1,], respectively. Unusual cations, that were stabilized as the SbC1, salts, have been prepared during the period under review, and they include [Me,_,S(NMe,),]' ( n = 1- 3)Ya [Me2NS0]',449b [(Me2N)2SC1]',449c [Me2NSC12]+,449C [H2C=NHMe]+,450 and [R1R2C=NH2]+(R1 = Me, R2 = H and R1 = R2 = Me).450 Bonds to Oxygen.-Antimony( 111 j Compounds. A structure for the oxide sulphate 3Sb203,2S03, i.e. Sb,O,(SO,),, which exists in equilibrium with 5M-H2SO4 in solution, showed the absence of water or hydroxy-groups that are present in species isolated similarly from nitric and perchloric Three different Sb polyhedra, described as lying between distorted tetrahedral and distorted trigonal- bipyramidal arrangements, are linked together in the structure; in all cases, the lone pair on the antimony atom is sterically active. Lone-pair activity was also found in the distorted tetrahedral SbO, units in the structure of MgSb204.452 The unusual anti-viral properties previously found for a tin heteropolyacid have now been observed in a number of other Group V derivatives, including (NH4),,Na[NaW21Sb9086],14H20453 and (NH4)16[W20Sb8080],32H20.454 A crystallographic investigation of the former showed differences from a normal Keggins structure, with, for example, the antimony atoms being included in a new type of unit containing Sb2WO:- groups. The product of the well-known test for antimony with pyrogallol is a monohydrate with a polymeric structure, in which each antimony atom is attached to four oxygen atoms from two pyrogallate ions, _ - as shown in (lOl)."" The structure also contains water are loosely connected to each of two antimony atoms. -~ ~ molecules, two of which Antimony (v) Compounds. The conversion of antimonic insoluble p-form has been found to be inhibited by behaves as a depolymerizing agent.456 Such solutions acid, (HSb03)-, into the phosphoric acid, which apparently contain two 449 W. W. Warthrnann and A. Schmidt, Z. anorg. Chem., 1975, 418, ( a) p. 57; ( b ) p. 61; ( c ) p. 145. 450 P. Volgnandt and A. Schmidt, Z. Naturforsch., 1975, 30b, 295. 451 J.-0. Bovin, Acta Cryst., 1976, B32, 1771. 452 C. Giroux-Maraine and G. Perez, Reu. Chim. mintrale, 1975. 12, 427. 453 J. Fischer, L. Ricard, and R. Weiss, J. Amer. Chem. SOC., 1976, 98, 3050. 454 B. Schonfeld, W. Bahr, B. Buss, and 0. Glernser, Z. Naturforsch., 1975, 3Ob, 831; B. Schonfeld, G. 455 B. Aurivillius and C. Sarnstrand, Acta Chem. Scand. ( A) , 1976, 30, 232. 456 J. P. Jolivet and J. Lefkbvre, Bull. Soc. chim. France, 1975, 2409. Steinheider, and 0. Glemser, ibid., p. 959. 232 Inorganic Chemistry of the Main - Group Elements distinct families of phosphoantimonic which, on separation, show ion- exchange Recent evidence suggests that in all polyantimonic acids the antimony atoms are in octahedral co-ordination by oxygen, but that in amorphous forms some of the oxygen atoms are present as OH groups, e.g. {H[SbOx~,(OH)6-,]},.459 I n the crystalline form, all oxygen atoms are shared, giving the formula [H(SbO6/,)],. Two new antimonates, uiz. Cd[SbO(OH),],O.l5H,O and Cdl.,5Sbo.70(OH)6, have been isolated from an ammoniacal solution of KSb(OH)6 and Cd2+.460 The compound formulated as VSbO, is in fact non-stoicheiometric, and phases such as V1-,Sbl-,04(M1-,02) are As the 12'Sb Mossbauer spectra indicate that only Sb" is present, the products are therefore V"' species. Powder and "'Sb Mossbauer data have been collected for the rutile-like compounds M"'Sb04 (M=Cr, Fe, Al, or Ga) and M"Sb206 (M=Mg, Co, Ni, or Zn).462 ( 102) On esterification with two moles of a 1,2-diol, phenylstibonic acid gives the spirocyclic compounds (102)T3 and a new complex between Sb" and tartaric acid, formulated as [Sb2(tart),H,I3-, has been isolated by partial neutralization of the well-known 1 : 1 complex.464 Bonds to Sulphur.-The antimony atom in the dithioester (103) is in pseudo- trigonal-bipyramidal co-ordination as a result of the 1,5-interaction often ob- served in similar In the dithiocarbamates M(S,CNEt,),, where M = Sb or Bi, the ligands are asymmetrically co-ordinated, as found for the arsenic compound, but here there is increasing intermolecular attraction, so that with bismuth an apparent dimer is formed.466 457 J. P. Jolivet, J. Lemerle, and J. Lefbbvre, Bull. SOC. chim. France, 1975, 2415. 4s8 J. P. Jolivet and J. Lefbbvre, Bull. SOC. chim. France, 1975, 2420. 459 B. G. Novikov, E. A. Materova, and F. A. Belinskaya, Russ. J. Inorg. Chem., 1975, 20, 876. 460 C. Lkvy-ClCment and A. Michel, Compt. rend., 1976, 282, C, 237. 461 T. Birchall and A. W. Sleight, Inorg. Chem., 1976, 15, 868. 462 J. D. Donaldson, A. Kjekshus, D. G. Nicholson, and T. Rakke, Acta Chem. Sc a d . (A), 1975, 29, 463 M. Weiber and N. Baumann, Z. anorg. Chem., 1975, 418, 279. 464 J . Mazieres and J. Lefbbvre, Rev. Chim. minirale, 1976, 13, 384. 46' M. Drager, Z. anorg. Chem., 1976, 424, 183. - C. L. Raston and A. H. White, J.C.S. Dalton, 1976, 791. 803. Elements of Group V 233 5 Bismuth Columns of trigonal-prismatic BiY6 units have been found in the structure of Y5Bi3T7 while the more usual distorted octahedral BiS6 unit occurs in CeBiOS2.468 A new ternary oxide, PdBi204, isostructural with the copper(I1) analogue, has been obtained from stoicheiometric quantities of PdO and Bi,03 at ca. 700 0C.469 The reaction between Bi13 and triphenylarsine oxide gave a complex, dinuclear product Bi216(Ph3As0)3, in which each bismuth atom was in approximately octahedral ~o-ordination.~~' The first atom is attached to three terminal and three bridging -iodine atoms (mean values 2.93 and 3.32 A), while the second is associated with the three bridging iodines and three oxygen atoms. Ready replacement of the bromine atoms in MeBiBr, and PhBiBr, occurred on treatment with sodium ethoxide, and the resulting diethoxides served as starting materials for a series of transesterification reactions with thiols, 1,2-diols, 1,2- dithiols, etc.471 Confirmation of [Bi(OH)]' and [Bi6(OH)12]6t. as the major species in the hydrolysis of Bi3' has been obtained from enthalpy titrations, but the data point also to the presence of a small amount of a further complex, tentatively identified as [Bi3(OH)4]5+.472 467 Y. Wang, E. J. Gabe, L. D. Calvert, and J. B. Taylor, Actu Cryst., 1976, B32, 1440. 468 R. Ceolin and N. Rodier, Actu Cryst., 1976, B32, 1476. 469 J.-C. Boivin, P. Conflant, and D. Thomas, Compt. rend., 1976, 282, C, 749. F. Lazarini, L. GoliE, and G. Pelizzi, J. Cryst. Mol. Structure, 1976, 6, 113. M. Wieber and U. Baudis, 2. anorg. Chem., 1976, 423, 40, 47. 470 471 472 A. Olin, Actu Chern. Scad. (A), 1975, 29, 907. Elements of Group VI BY M. G. BARKER 1 Oxygen The Element.-The chemical reactivity of singlet oxygen ('A,) produced in the gas phase by an electric discharge has been studied both in homogeneous systems' and in heterogeneous gas-liquid The reactions of atomic oxygen ('P) with methanol and ethanol have been investigated as a function of temperature, and absolute rate constants fitted to appropriate eq~ati ons.~ The pure rotational Raman spectra of I6O2, l60l8O, and 1 8 0 2 have been recorded and analysed, the latter two for the first time.5 Oxygen 1s and carbon 1s binding energies have been measured for a variety of compounds containing the carbonyl group. It was concluded that most of the oxygen 1s ionizations include a rather large amount of electronic relaxation corresponding to the w-electron donation from the groups bonded to the carbonyl groups. Two different methods were employed for the derivation of .rr-donor relaxation energies, but, since both sets of values are in fair agreement, either may be used to estimate the relative w-donor abilities of substituents.6 The viscosities of oxygen and air have been measured over the temperature range 120-1620K, using a capillary-flow method over a range of gas pressures.' In the oxidation of T1,S by molecular 0, the compounds T12S0 and T12S02 are thought to be formed. The former compound dissolves in DMSO to give a dimer (l), containing both TI1+and T13+. From this and other observations it was /*\ \o/n--s-n- TI-ST1 (1) concluded that oxidation of T1 took place before oxidation of sulphur in the sulphide.' The reaction of gaseous oxygen with segregated sulphur on a polycryst- alline surface has been studied by Auger electron spectroscopy between 700 and J. L. Dumas, Bull. SOC. chim. France, 1976, 658. J. L. Dumas, Bull. SOC. chim. France, 1976, 662. J. L. Dumas, Bull. SOC. chim. France, 1976, 665. C. M. Owens and J. M. Roscoe, Canad. J. Chem., 1976, 54, 984. ' H. G. M. Edwards, E. A. M. Good, and D. A. Long, J. C. S. Faraday IZ, 1976, 72, 865. ' W. L. Jolly and T. F. Schaaf, J. Amer. Ge m . SOC., 1976, 98, 3178. ' G. P. Matthews, C. M. S. R. Thomas, A. N. Duffy, and E. B. Smith, J.C.S. Faruday I, 1976,72,238. V. I. Rigin and S. S. Batsanov, Russ. J. Inorg. Chem., 1975, 20, 1283. 234 Elements of Group VI 235 1300 "C. At temperatures around 800 "C, reaction is predominantly between ambient oxygen and surface sulphur to form sulphur dioxide molecules, followed by the adsorption of oxygen at the vacant sites which reacts very slowly with the surface sulphur at this temperature. At 1200 "C surface diffusion is rapid and the dominant process becomes the reaction between the surface sulphur and chemisorbed oxygen.' Molecular oxygen adsorbed on Ti 02 and subjected to U.V. radiation gives rise to three paramagnetic species; O,, O,, and O:-. The latter reacts rapidly with CO at 77 K, giving the species 0-0-CO- in which the two directly bonded oxygen atoms originate from the adsorbed molecular 0xygen.l' The species 0, has been observed during oxygen adsorption on Tho2 surfaces in the presence of CO or hydrogen adsorbates; e.s.r. methods were used to follow the kinetics of formation of the species.ll The reaction of molecular oxygen with atomically clean nickel surfaces has been studied by field emission microscopy at temperatures from 78 to 500 K, and oxygen pressures from 10-l' to 1.0 Torr.12 Ozone. The rate constant for the reaction (1) has been measured over the temperature range 22 1-629 K by atomic resonance abs~rpti on.'~ The valence 0, +~1("~3,2) + C ~ O +0 2 (1) ionic states of ozone have been studied, using a combination of multiconfiguration self-consistent field theory and configuration mixing methods.14 It was found that the states of lower energy show a significant mixing of one-electron ionization and two-electron simultaneous ionization-excitation processes, leading to the pre- dicted appearance of intense satellite bands in the U.V. photoelectron spectrum. The valence p.e. spectra of 0, cannot therefore be interpreted in terms of the usual, one-electron orbital ionization processes. The kinetics of the gas-phase reaction of ozone with ethylene, propylene, and trans-2-butene have been studied as a function of a number of experimental ~ariab1es.l~ Hydrogen Peroi de and Hydrogen-Oxygen Species.-The photoreduction of H202 in water under H2 of up to 100atm pressure has been shown to involve a chain mechanism with a maximum quantum efficiency at a peroxide concentration of about 5 X mol 1-'.l6 Metal-free phthalocyanine and eosin act as photo- sensitizers for the fast autoxidation of methanol in alkaline solution, during which H202 accumulates. The rate of formation of H202 further increases if the reaction takes place in the vicinity of an electrode on which H202 and phthalocyanine are oxidized." Hydrazine may be oxidized by H202 in the presence of Cu2+ to form N2 and H2U.ls The p.e. spectra of several peroxides have been measured. It was found that the highest occupied M.O. is antibonding with respect to the 0-0 T. Kawai, K. Kunirnori, T. Kondow, T. Onishi, and K. Tamaru, J.C.S. Faraday Z, 1976, 72, 833. lo P. Meriaudeau and J. C. Vedrine, J.C.S. Faraday ZZ, 1976, 72, 472. l1 M. Breysse, B. Claudel, and P. Meriaudeau, J.C.S. Faraday I, 1976, 72, 1. l2 G. D. W. Smith and J. S. Anderson, J.C.S. Faraday Z, 1976, 72, 1231. l 3 M. A. A. Clyne and W. S. Nip, J.C.S. Faraday ZZ, 1976, 72, 838. l4 H. Basch, J. Amer. Chem. Soc., 1975, 97, 6047. l5 S. M. J apor, C. H. Wu, and H. Niki, J. Phys. Chem., 1976, 80, 2057. l6 R. J . Field, R. M. Noyes, and D. Postlethwaite, J. Ptrys. Chem., 1976, 80, 223. M. Heyrovsky and Yu. S. Shumov, Coll. Czech. Chem. Comm., 1976, 41, 1860. '* C. R. Wellman, J . R. Ward, and L. P. Kuhn, J. Amer. Chem. Soc., 1976, 98, 1683. 17 236 Inorganic Chemistry of the Main- Group Elements linkage. In addition, the dependence of the splitting of the two highest occupied M. 0. s on the dihedral angle was verified by the p.e. spectra of several well- defined cyclic peroxides.lg A single crystal of HBr,2H20 has been grown and subjected to neutron- diffraction analysis, which made it possible to measure the H,Oi ion exactly.20 Figure 1 shows the cation in which the central CbH- 0 bridge is remarkably Figure 1 The H,O, cation in hydrogen bromide dihydrate (Reproduced by permission from Angew Chem. Internat. Edn., 1976, 15, 491) short (mean value of previously determined 0-0 distances =2.44&. The hydrogen atom is not exactly central, even in this short bridge, a fact which can be correlated with the slightly asymmetrical environment of the two oxygen atoms. The influence of neutral salts on the easily polarizable hydrogen bond of H,Oh groupings in aqueous acid solutions has been studied by i.r. spectroscopy?1 The decrease of the absorbance of the i.r. continuum with increasing salt concentration was explained by the polarization of the hydrogen bonds by local fields due to the neutral salt ions. 'H n.m.r. signals due to long-lived H30+, H2DO', and HD20+ ions have been observed in partially deuteriated HS03F-SbFS-H20 systems in SO, or S0,ClF solutions, thereby providing unambiguous spectroscopic evidence for the existence of H30+ ions without further hydration in solution.22 The reaction of HO, with NO has been studied at room temperature, in competition with the reaction 2H023 H202 + 02, and the competition for HO, between NO and NO, has been studied by monitoring NO removal.23 The electrochemical behaviour of water in molten LiN03-KNO, eutectic has been in~estigated.,~ Contrary to previous reports, the electroreduction of water in nitrate melts appears to be coupled with nitrite reduction, probably involving an autocatalytic mechanism and an adsorbed intermediate. l9 R. S. Brown, Canad. J. Chem., 1975, 53, 3439. 2o R. Attig and J. M. Williams, Angew. Chem. Zntemat. Edn., 1976, 15, 491. 21 D. Schioberg and G. Zundel, Canad. J. Chem., 1976, 54, 2193. 22 V. Gold, J. L. Grant, and K. P. Morris, J.C.S. Chem. Comm., 1976, 397. 23 R. Simonaitis and J. Heicklen, J. Phys. Chem., 1976, 80, 1. 24 D. G. Lovering, R. M. Oblath, and A. K. Turner, J.C.S. Chem. Comm., 1976, 673. Elements of Group VI 237 2 Sulphur The Element.-The properties of sulphur-sulphur bonds have been re~i ewed.2~ The review deals with isolated S-S single bonds, cumulated S - S bonds, differing co-ordination numbers for the sulphur atoms in C S bonds, and the properties of extremely long S-S bonds. The properties emphasized are: bond lengths and angles, stretching vibrations, force constants, and M.O. descriptions. Atomic force constants for sulphur in the ring compounds S6, Sg, and S,, have been found to be 475*22mm-', and to be transferable between the three compounds.26 More precise crystallographic parameters have been reported for monoclinic Two thirds of the crown-shaped S, rings are in general positions without any disorder, the others being located around centres of symmetry. The crown lacks centric symmetry, and the molecules gain this symmetry by disorder between two orientations, each occupied with 50% proba- bility. The bond distances are all equal (within error), with a weighted average of 2.045 A, and bond angles ranging from 106.5 to 109.3', with a weighted average of 107.9'. The laser Raman spectrum of a crystal of monoclinic @-sulphur has been recorded at various temperatures above and below the transition point. The frequencies of the internal modes are close to those of a-sulphur. The external modes show a behaviour typical of disordered crystals, with a progressive ordering of the molecules as the temperature is lowered.28 The kinetics of the S,-S, transformation in a crystalline medium have been investigated. The transformation is a zero-order, reversible reaction, and the results are explained using a hypothesis concerning the allotropes S, and S, as conformers of the cyclic molecule SS?' Sulphur molecules S,, with values of x from 2 to 22, have been desorbed from a condensed sulphur layer on a tungsten field emitter of a field ionization, time-of-flight mass spectrometer. The con- densed layer was found to be in a highly mobile, liquid-like, steady state. The observation of these large sulphur molecules is relevant to the current models of liquid Studies of the e.s.r. spectrum of sulphur-oleum solutions have revealed the existence of the radical species S5.3' Sulphur-Halogen Compounds-The Raman spectra of gaseous, liquid, and solid SF4 have been ~e-exami ned.~~ Polarization measurements allowed the unambig- ous identification of the A, modes. The i.r. spectrum of SF,, isolated in a nitrogen matrix, showed that the 353cm-' absorption consists of two fundamentals, thus providing the hitherto missing ninth fundamental of SF4. The photolysis of SF4 in an argon matrix at 8 K has been shown to give significant amounts of two products, which were tentatively identified as the SF,. radical and SF2. A band at 682.2 cm-' was assigned to the F-S-F antisymmetri- cal stretching mode of SF3* and a band at 846.8cm-' to the asymmetrical 25 R. Steudal, Angew. Chem. Internat. Edn., 1975, 14, 655. " W. T. King, Spectrochim. Acta, 1975, 31A, 1421. '' L. K. Templeton, D. H. Templeton, and A. Zalkin, Inorg. Chem., 1976, 15, 1999. 29 M. F. Churbanov, I. V. Skipachev, and G. G. Devyatykh, Russ. J. Inorg. Chem., 1976, 21, 439. 30 D. L. Cocke, G. Abend, and J. H. Block, J. Phys. Chem., 1976, 80, 524. 31 H. S. Low and R. A. Beaudet, J. Amer. Chem. Soc., 1976, 98, 3849. 32 K. 0. Christe, E. C. Curtis, 3. C. Schack, S. J.Cyvin, J. Brunvoll, and W. Sawodny, Spectrochim. G. Gautier and M. Debeau, Spectrochim. Acta, 1976, 32A, 1007. Acta, 1976, 32A, 1141. 238 Inorganic Chemistry of the Main - Group Elements stretching vibration of SF,.33 The reactions of iminophosphoranes with SF, for the synthesis of symmetrically and unsymmetrically substituted sulphur di-hides, bis(su1phur di-imides), bis(iminosu1phur difluorides), cyclic sulphur di-imides, and 1,2,5thiadiazoles, have been de~cribed.~, The reactions of SF6 at high temperatures and pressures with several carbon- sulphur and carbon-xygen compounds have been At temperatures above 485°C and a pressure of 1360atm, SF6 reacts with Cs, to yield (CF3),S, (CF,),S,, C, and S: reaction at 500 "C and 270 atm with COS gives CF,, SOF,, and S. No reaction was observed with CO or CO, below 500 " C and 4000 atm. This lack of reaction was explained by the formation of SF, via a co-ordinated intermediate (2), which decomposes to SF,. S.C.F.-X, scattered-wave calculations have been used to examine the nature of the bonding in some sx6 ( X= F, C1, or H) molecules and in SF4 and SoF4.36 Evidence from optical absorption pulse radiolysis experiments has been presented for the existence of an oxidizing radical, other than OH, produced by the reaction of SF, and e& This radical (which is thought to be SF5*) is capable of oxidizing phenol and hydroquinone directly to phenoxyl and p-semiquinone ion radicals respectively, even at neutral pH.37 The i.r.-active combination bands of SF, gas have been remeasured and the data combined with older data to derive the vibrational constants and force fields of SF6.38 The reactions of positive ions produced from SF6 with neutral amines NHyR3-y (R = Me) have been studied. An important reaction involves transfer of F- to the amine from SF:, and other processes involve condensation of the amine and the SF: (n = 5 or 3) ions with elimination of HF.39 A d.t.a. study has shown that in the temperature range 500-800 "C, SF, reacts with oxides of Group I1 and I11 elements with considerable evolution of heat. The gaseous products were found to be SO, and sulphuryl fluoride, with thionyl fluoride being observed in the reaction of A1203 with SF,.,' The first matrix- isolation and i.r. spectral identification of the SF5- radical, as produced by the vacuum-u.v. photolysis of SF6 and its derivatives, and by controlled attack by fluorine atom on SF4, has been announced?1 Compounds of the type SF5- N=S(F)NR, and SFrN=S(NR2), have been prepared by Si-N bond-cleavage reactions of silylamines with pentafluorosulphur-sulphur difluoride imide; the 33 R. R. Smardzewski and W. B. Fox, J. Fluorine Chem., 1976, 7, 353. 34 R. Appel, J.-R. Lundehn, and E. Lassmann, Chem. Ber., 1976, 109, 2442. 3s A. P. Hagen and B. W. Callaway, Inorg. Chem., 1975, 14, 2815. 36 N. Rosch, V. H. Smith, and M. H. Whangbo, Inorg. Chem., 1976, 15, 1768. 37 K. M. Bansal and R. W. Fessenden, J. Phys. Chem., 1976, 80, 1743. 38 R. S. McDowell, J. P. Aldridge, and R. F. Holland, J. Phys. Chem., 1976, 80, 1203. 39 J. G. Dillard and J. H. Troester, J. Phys. Chem., 1975, 79, 2455. A. A. Opatovskii, E. U. Labkov, V. N. Lyubimov, Yu. V. Zakharev, V. N. Grantin, and V. N. Mitkin, Russ. J. Inorg. Chem., 1975, 20, 663. 40 41 R. R. Smardzewski and W. B. Foo, J. Fluorine Chem., 1976, 7, 456. Elements of Group VI 239 latter also reacts with PC1, to give SFS-N=SC12.42 The reactions of sulphur chlorides with P(CN), and S(CN), have been reported. The reaction of P(CN), with SC1, is complex, with the likelihood that two simultaneous reactions occur, one to give cyanuric chloride and the other to give 3,5-dichloro- 1,2,4-thiadiazole (3); see reactions (2) and (3). The reaction of P(CN), with S2C12 also yields (3), P(CN), + 5SC1, -3 PSC1, + Cl,C,N, + 2S2C1, (2) P(CN), + 7sc1, + 2PSC1, + 3C1,C,N2S + S,C1, (3) (3) together with PSCl,. The reactions of S(CN)2 with SC12 and S,Cl, gave thiocyanogen trichloride, CIS-N=CCl,, and carbamoimidic dichloride disul- phide, Cl,C=N-S-S-N=CCl,, re~pectively.~~ The salts [S,I]'[MF,]- (x = 7 or 8; M = As or Sb) have been prepared by various reactions; the crystal structure of [S,I]+[SbF6]- the cation to contain iodine bonded to a sulphur atom of a seven-membered sulphur ring (Figure 2). Figure 2 Structure of &I]+ and an interacting anion, [SbF6]-: S(l)-S(2), 2.09(1); S(2)-S(3), 1.99(1); S(3)-S(4), 2.11(1); S(4)-S(5), 1.96(1); S(5)-S(6), 2.17(1); S(6)-S(7), 1.92(1); S(7)-S(1), 2.37(1); S(1)-I, 2.347(6); S(6)-I, 3.384(8); S(l)-F(3'), 2.94(4); I-F(2), Sb-F(5), 1.85(4); and Sb-F(6), 1.83(2)A; LI-S(1)-S(2), 107.6(3); I-S(l)-S(7), 100.5(3) ; S( 2)-S( 1)-S( 7), 102.5(4) ; S( 1)-S(2)-S( 3), 108.0(4) ; S( 2)-S( 3)-S(4), 105.3(4); S(3)-S(4)-S(S), 104.2(4); S(4)-S(5)-S(6), 105.0(4); S(5)-S(6)-S(7), 108.4(5); S(6)-S(7)-S( l), 106.1(4) ; S&F(2)-1, 1 19( 1); S( 1)-I-F(2), 173.6(5) ; and 2.92(2); Sb-F(l), 1.84(2); SbF(2), 1.91(2); Sb-F(3), 1.83(3); Sb-F(4), 1.86(4); F-Sb-F (average), 90.0" (Reproduced from J. C. S. Chem. Comrn., 1976, 689) Gaseous methyl sulphenyl chloride has been shown to react with active KF at 100 "C to give methyl(fluoromethy1)disulphane. At room temperature the latter decomposes according to equation (4).45 2MeSSCH,F + MeSSMe + CH,FSSCH,F (4) Methyltrifluorosulphurane, MeSF,, has been prepared either by the reaction of gaseous methylchlorosulphane with AgF, or by the reaction of CF,SF with MeSCl R. Hofer and 0. Glemser, 2. anorg. Chem., 1975, 416, 263. J . Passmore, P. Taylor, T. K. mi dden, and P. White, J.C.S. Chem. Comm., 1976, 689. 42 43 A. E. Barnett, P. Piotis, and B. Tittle, J. Inorg. Nuclear Chem., 1976, 38, 1575. 45 W. Gombler, 2. Naturforsch., 1976, 31b, 727. 240 Inorganic Chemistry of the Main- Group Elements or MeSSMe.46 The compound is extremely sensitive to hydrolysis, and it attacks glass, yielding methylsulphinyl fluoride. The reactions of CF,SF, with silanes of the general formula MeSiR, where R = H, Cl, NMe2, NHMe, NMeSiMe,, or SMe, have been de~cribed.~’ Treatment of CF3SF3 with Me,SiNMe, results in the production of CF,SF,NMe,, and reaction with Me,SiOMe leads to a mixture of CF3SF20Me and CF,S(O)F,Me. All other silane reactions resulted in the forma- tion of decomposition products. (4) Two reactions have been described which lead to the formation of HOSF5 (4); see equations ( 5) and (6). In reaction ( 5) , HOSF, was only detectable by n.m.r. ClOSF, + H,O HOCl + HOSF, ( 5) ClOSF, + HC1 C1, + HOSF, (6) spectroscopy, but in reaction (6) the product was obtained as a white solid, any C12 and excess HCl being removed by pumping at -95°C. The pure compound exhibits the expected decomposition to SOF, and HF on melting at ca. -65°C; this decomposition occurs slowly even at -78”C, probably because the short H * - - F distance (-1.9 A) favours elimination of HF.48 The kinetics of the thermal decomposition of F,SOOSF, have been investigated in quartz vessels at temperatures between 213 and 243°C. In the absence of all substances which might react with the primarily formed radicals, the only final products formed are OSF4 and F5SOF; however, under these experimental conditions, the FSSOF decomposes slowly, forming SF6 and 02.49 Photolysis reactions of CF,SF,Cl with H2, CF,CN, and ClCN have been shown to give CF,SF4SF4CF3, CF3SF4N=C(Cl)CF3, and CF3SF4N=CC12, respe~ti vel y.~~ The new compounds CF,SF(O)=NCF, and CF,SF(=NCH,)NCF, have been shown to result from nucleophilic displacement reactions of CF,SF3=NCF3 with water and methylamine, respectively. Higher yields of the di-imine were obtained when MeN(SiMe,), was substituted for MeNH,. A series of stable fluoroamines CF,SF,N(F)R, (Rf = CF, or C2F5) were also prepared, and it was shown that they possess greater chemical stability than the chloro-amine~.~~ Reactions of SFSNCO, SFSNH2, SF,N=SF,, SF,N=SCl,, and SFSN=CCl, with appropriate substrates have been shown to produce SF,N=SMe,, SF5N=CHPh, SFSN=CC12, SF,N=SCl,, (SF,N=),C, (SF,N=),S, and SF,N=PC1,.52 46 W. Gombler and R. Budenz, J. Fluorine Chem., 1976, 7, 115. 48 K. Seppelt, Angew. Chem. Intemat. Edn., 1976, 15, 44. 49 J. Czarnowski and H. J. Schumcher, J. Fluorine Chem., 1976, 7, 235. ” S. L. Yu and J. M. Shreeve, Inorg. Chem., 1976, 15, 14. 51 S. L. Yu and J. M. Shreeve, J. Fluorine Chem., 1976, 7, 85. G. H. Sprenger and A. H. Cowley, J. Fluorine Chem., 1976, 7, 346. 47 A. F. Clifford and A. Shanzer, J. Fluorine Chem., 1976, 7, 65. 52 Elements of Group VI 241 Sulphur-Oxygen-Halogen Compounds.-Chemical analysis of a relatively stable complex of methyl fluoride-antimony pentafluoride, prepared from solution in SO,, showed it to contain bonded SO,. A reinvestigation of the solution of the MeF-SbF, system in SO, and in S0,ClF revealed that both SO, and S0,ClF may be 0-methylated, giving stable non-exchanging ions5, ( 5) and (6). CI + I I Me6=C-O SbF,- (or Sb,F;,) MeO=S=O SbF,- (or Sb,F;,) ( 5) ( 6) SOCl, has been shown to react with either CF,S(O)N(SiMe,), or CF,S(O)NH- SiMe, to form CF,S(O)N=S=O, a compound with two sulphur atoms in oxida- tion state 4+. I n contrast to N(SiMe3)3, the tin analogue reacts with CF,S(O)Cl to give CF3S(0)OSnMe3.54 Fluorosulphuryl isocyanate has been found to react with HgF, and CdF, in MeCN solution to form the fluoroformyl fluorosulphurylimide salts Hg[N(SO2F)C(O)FI2,xMeCN(x = 1 or 2) and Cd[N(SO2F)C(0)F],,2MeCN. The reaction with CdF, was incomplete, and no detectable reaction occurred with ZIIF,.’~ The reaction of RS(O)Cl with NaN[SiMe,],, shown in equation (7), has been shown to yield the trimethylsilylated sulphinic amides (7). The imidate RS(0)Cl + NaN(SiMe,), - RS(O)N(SiMe,), +NaCl (7) (7) structure (8) was assigned unequivocally to (7) where R = Me,C and Me,N, and the same structure was also suggested for the known compound where R = Ph on the basis of its spectroscopic proper tie^.^^ , 0-SiMe, %-siMe, R-S (8) A series of 1 : 1 adducts of imidobis(sulphury1 chloride) and some Lewis bases has been prepared. Conductivities and i.r. data revealed that the nitrogen atom of the bases is co-ordinated to the labile hydrogen atom of the imidobis(sulphury1 chloride), giving a N-H bonded cation and the [N(SO,Cl),]- anion.57 1.r. and Raman spectra have been recorded for liquid MeOS0,Cl as well as the i.r. spectra of the vapour and of solutions in CCl,. With the exception of the two torsional modes, all fundamentals were observed and assigned on the basis of C, symmetry.” 53 G. A. Olah, D. J. Donovan, and H. C. Lin, J. Amer. Chern. Soc., 1976, 98, 2661. H. W. Roesky and G. Holtschneider, J. Fluorine Chern., 1976, 7, 77. 55 R. E. Noftle, J. W. Green, and S. K. Yarbro, J. Fluorine Chem., 1976, 7, 221. A. Blaschette, D. Rinne, and H. C. Marsmann,.Z. anorg. Chern., 1976, 420, 55. 57 R. C. Paul, P. Kapoor, R. Kapoor, and R. D. Verma, Indi an J. Chern., 1975, 13, 1184. B. Nagel, J. Stark, J. Fruwert, and G. Geiseler, Spectrochim. Acra, 1976, 32A, 1297. 56 242 Inorganic Chemistry of the Main- Group Elements Benzylic sulphides have been shown to give sulphonyl chlorides in excellent yields upon reaction with molecular chlorine in aqueous acetic acid. The reaction is thought to proceed through the intermediacy of the corresponding sulphenyl ~hloride.~' Gas-phase i.r. and liquid-phase Raman spectra have been reported, and vibrational assignments made for CF,S(O)F, CF,S(O)Cl, and FS(0)Cl. Meas- urements of the depolarization ratio indicated that the compounds are pyramidal, in agreement with lone-pair repulsion considerations.60 Perhalogenoalkyl sul- phuroxidifluoride imides RNSOF2 (R = CF3, C2F5, i-C3F7, CF,Cl-CF,, and CF,Br-CF,) have been isolated in high yield from the photochemical reaction of OF, with the appropriate difluoride imides; in all the reactions studied, the difluoride di-imides RN=SF2=NR were found as by-products."' Sulphur-Nitrogen Compounds.-Linear Molecules. The synthesis of the stable bis(trifluoromethyl)sulphimide, (CF3)$S=NH, by the reaction of ammonia with bis(trifluoromethy1)sulphur difluoride in the presence of a primary amine, has been reported.", The reaction of (CF,),S=NH with n-butyl-lithium gives a white crystalline solid, (CF3),S=NLi, which is a useful precursor to a variety of stable substituted sulphimides [reaction (8)], thus providing an opportunity to compare the reactivities and general properties of the (CF3)2*N- system with that of (CF3)2 CbN-. (CF,),S=NLi 4 RC1 + (CF,),S==NR +LiCl (8) R=Me, S, CF,C(O), or CF,S Fluorosulphinyl imidosulphur oxide difluoride (9) has been prepared [equation (9)]. The compound, which is the first representative of the hitherto unknown series of halogenosulphinyl imidosulphuroxide difluorides, gives an unusual 19F n.m.r. spectrum. Instead of the expected doublet and triplet, it contains a quartet 0 2FS(O)Cl +Hg(NSOF,), - 2 \S/" SYo +HgC1, (9) F ' F / \ F at -57.98 p.p.m. (SOF) and an octet at -52.48 p.p.m. (ABX type), thus indicating that the fluorine atoms of the NSOF, group are diastereotopic and couple with each other as well as with the F atom attached to the unsymmetrically substituted S atom of the sulphinyl NN'-Di- t-bu tylsulp hurdi-imide (1 0) and N- t-bu tyl-N '-phenylsulphurdi-imide react with halogeno- and organo-sulphonyl isocyanates (1 1) to form N-organyl- N'-sulphonylsulphurdi-hides (12) and t-butyl isocyanate [equation (lo)]. At R. L. Langler, Canad. J. Chem., 1976, 54, 498. R. L. Kirchmeier and J . M. Shreeve, Inorg. Chem., 1975, 14, 2431. I. Stahl, R. Mews, and 0. Glemser, J. Fluorine Chem., 1976, 7, 55. S. D. Moorse and J. M. Shreeve, J.C.S. Chem. Comm., 1976, 560. H. J . Krannich and W. Sundermeyer, Angew. Chem. Internat. Edn., 1976, 15, 311. 59 60 61 62 63 Elements of Group VI 243 low temperatures N-sulphonyl-t-butylamine, in the presence of halogeno- sulphonyl isocyanates, partially exchanges the sulphinylamino-group for the isocyanate group [equation (I I)]."" Bu'N=*NBut + XSO,-N=C+O Bu'N=S=N-SO,X +ButNCO (10) (10) (11) (12) X = F, C1, Ph, or p-MeC6H4 Bu'-NSO +FSO,-N=C=O Bu'-N=*O + F-SO,-NSO (11) The aminomercaptosulphurdi-imides (1 3) have been prepared by the reaction of monosilylated sulphurdi-imides (14) with aminosulphenic acid chlorides. On reaction of (14) with dichlorosulphane, the sulphur di-imidosulphanes (15) are formed .65 ButN=S=N-SiMe, +R,N-SCl -+ ButN=S=N-SNR, + MeSiCl (12) (14) (13) R =Me or Et Bu'N=S=N-SiMe, +SC1, + Bu'NSNSNSNBut +2Me3SiC1 (13) (14) (15) Substituted sulphurdi-imides have also been prepared by the reactions of MeSiN=S=NSiMe, with MeS0,Cl and CC1,SCl or with P203F4 and Me,SiN=S=N-SNMe,. However, S4N4 reacts with Me,Si(NMe,), to form Me,Si(NMe,)-N=S=N-SNMe,, while S3N,C12 yields Me,Si(Cl)-N=S=N- SNMe,. The chlorine atom in the latter may also be substituted by diethylamine. These new compounds are intermediates for the synthesis of cyclic S- N com- pounds.66 Tetrakis-trimethylsilyl-substituted sulphamide has been obtained from the reaction of NN'-bis(trimethylsilyl)sulphamide, butyl-lithium, and trimethyl- bromosilane. Its structure is that of NNN'O-tetrakis(trimethylsily1)sulphamide (16a). Tris(trimethylsily1)amidosulphonic acid (16b) and N-alkyltrimethylsilyl- amidosulphonic acids can readily be obtained from silyl-amines and trimethyl esters of chlorosulphonic (16) a; X =NSiMe, b ; X= O The thermal decomposition of bis(pyrro1id- 1-yl) disulphide has been studied over the temperature range 45-68 "C. The results indicate a relatively weak S- S bond in bis(dialky1amino) disulphides and appreciable stability for the thionitrox- ide radicals (R2NS*).68 The kinetics of the disappearance of sulphonic acid in 64 R. Appel and M. Montenarh, Chem. Ber., 1976, 109, 2437. " R. Appel and M. Montenarh, Z. Nuturforsch., 1975, 30b, 847. 66 H. W. Roesky, W. Schaper, W. Grosse-Bowing, and M. Dietl, 2. unorg. Chem., 1975, 416, 306. 68 W. C. Danen and D. D. Newkirk, J. Amer. Chem. SOC., 1976, 98, 516. W. Buss, H. J. Krannich, and W. Sundermeyer, Z. Naturforsch., 1975, 30b, 842. 67 244 Inorganic Chemistry of the Main- Group Elements concentrated HNO, have been shown to be first order with respect to the concentration of sulphonic acid.69 Polymeric Sulphur Nitride. It has been shown that, when crystals of (SN),, prepared by the solid-state polymerization of S2N2, are heated at ca. 145 "C and the issuing vapours are pumped over a glass cold-finger condenser at 25 "C, golden films of (SN), are When S4N4 is heated at 70 "C and the vapour is pumped over glass or oriented plastic substrates, crystalline films are deposited directly from the vapour phase onto the substrates. These films are identical to those obtained by the sublimation of (SN),, and consist of essentially completely aligned parallel (SN), polymer chains.72 In an attempt to shed some light on the depolymerization and repolymerization processes which occur on the sublimation of (SN),, a matrix-isolation study has been carried out. Preliminary results indicate that under these conditions the volatilization of (SN), at 140-160 "C produces some S2N2 molecules, and possibly a trace of SN; but mostly the well-known cyclic S,N, molecules and more than one unidentified ~pecies.'~ Crystals of (SN),, for a structural determi nati ~n,~~ have been formed by slowly growing crystals of S2N2 at 0°C from the vapour phase, followed by polymeriza- tion at room temperature and at 75 "C. The crystals are composed of an ordered array of parallel (SN), fibres which consist of alternating S and N atoms in an almost planar chain. For comparison, a single-crystal study of S2Nz at -130°C was carried out. The molecule was shown to be square planar, and in Table 1 the crystallographic parameters are compared with those of (SN),. To complement the previous studies, a further determination of the crystal structure of (SN), at -145 "C, and the structure of partially polymerized S2N2, has been carried Table 1 Crystallographic parameters of (SN), and S2N2 Parameter Space group Cell dimensions al A blA CIA PI" pJg cmV3 z S-N bond lengthsJ A S-N-S angler N-S-N angle/" R (SNL P2JC 4.153 4.439 7.637 109.7 2.30 4 1.593 1.628 119.4 106.2 0.11 4.485 3.767 8.452 106.43 2.23 2 1.657 1.651 90.4 89.6 0.03 69 D. Attwood and G. Stedman, J.C.S. Dalton, 1976, 508. A. A. Bright, M. J. Cohen, A. F. Garito, A. J. Heeger, C. M. Mikulski, P. J. RUSSO, and A. G. MacDiarmid, Phys. Rev. Letters, 1975, 34, 206. A. A. Bright, M. J. Cohen, A. F. Garito, A. J. Heeger, C. M. Mikulski, and A. G. MacDiarmid, Appl. Phys. Letters, 1975, 26, 612. 72 E. J. Louis, A. G. MacDiarmid, A, F. Garito, and A. J. Heeger, J.C.S. Chem. Comm., 1976, 426. 73 R. A. Teichman and E. R. Nixon, Inorg. Chem., 1976, 15, 1993. 74 C. M. Mikulski, P. J. Russo, M. S. Saran, A. G. MacDiarmid, A. F. Garito, and A. J. Heeger, J. 75 M. J. Cohen, A. F. Garito, A. J. Heeger, A. G. MacDiarmid, C. M. Mikulski, M. S. Saran, and J. 70 71 Amer. Chem. SOC., 1975, 97, 6358. Kleppinger, J. Amer. Chem. SOC., 1976, 98, 3844. Elements of Group VI 245 Cyclic Sulphur-Nitrogen Compounds. The recent chemistry of cyclic sulphur- nitrogen-halogen compounds has been described. The review is divided into sections on cyclothiazenes having the halogen covalently bonded to the ring and cyclo- thiazenes with ionic bonding of the halogen; both preparative and structural aspects are covered.76 Some previously unpublished material is also included in a second review of the preparations and reactions of S-N ring ~ystems.~’ The structure and ionization spectrum of S2N2 have been discussed, using the ab initio M.O. method, the predicted square-planar geometry being in excellent agreement with the experimental The five-membered sulphur- nitrogen-oxygen ring compound (18) has been prepared by the reaction of the tin compound (17) and SOF,. Compound (18) reacts with FS02N=S=0 to yield (19), for which some crystallographic data have been given. The terminal fluorine atom of (19) may be replaced by CF3 or n-C,F, by the reaction of (18) with CF,SO,N=C=O or n-C4F9S02N=S=0, respe~ti vel y.~~ +SOF, - 2 0 2 - 1 k=S + 2Me2SnF2 (14) The -CF, derivative is also a product in the reaction of S4N, with CF3SO20SO2CF3, but of more importance is the S3Ni radical cation (20), which is also produced in the reaction as the CF,SO, salt.80 An independent study has S4N4 +CF3S0,0S02CF, shown that the reaction compound S3Ni AsFi. A of S4N4 with AsF, also yields the S,N: ion in the structural investigation showed it to consist of discrete AsF, and planar cyclic S3N2 ions (21). Solutions of the compound in methylene 76 0. Glemser, 2. Naturforsch., 1976, 31b, 610. 77 H. W. Roesky, 2. Naturforsch., 1976, 31b, 680. 79 H. W. Roesky, G. Holtschneider, H. Wiezer, and B. Krebs, Chem. Ber., 1976, 109, 1358. M. P. S. Collins and B. J. Duke, J.C.S. Chem. Comm., 1976, 701. H. W. Roesky and A. Hamza, Angew. Chem. Intemat. Edn., 1976, 15, 226. 246 Inorganic Chemistry of the Main- Group Elements chloride gave e.s.r. spectra showing that the unpaired electron in S3Ni is coupled to two equivalent nitrogen atoms, in full accord with the crystal structure.8' N-Diorgano-N"-bis(trimethylsily1)sulphamide (22) and NNN'N'-tetrakis- (trimethylsily1)sulphamide (23) have been shown*, to react with trithiadiazyl dichloride to give the trithiazolidenes (24) and (25). RS0,-N(SiMe,), + S,N,Cl, -+ RS02-N=S /"r + 2Me3SiC1 (16) \N-S (24) n (22) R= Me,N or 0 (Me,Si),N-SO,-N(SiMe,), [-' $=N--SO,-N=S ( 25) (23) - C-N + + S3N2Cl 4Me3SiC1 Whereas the alkylation of the silver salt (26) with methyl and ethyl iodide takes place at the N atoms adjacent to the SO, group, an oxygen-bonded product (27) has been shown [equation (18)] to be formed on reaction with Me3MCl (M= Si or Sn). The NMe: salt of the NMe-substituted compound can be prepared and converted into the silver salt (28), which on reaction with Me1 gives 90% methylation at the N atom between the S(O)NMe, and SO, groups [equation (19)].83 The reaction of SzClz with aqueous ammonia to produce S4Nz has now been examined quantitatively, Reaction at 5 "C was found to give maximum yield ,0-MMe, " R. J. Gillespie, P. R. Ireland, and J. E. Vekris, Canad. J. Chem., 1975, 53, 3147. 82 M. Montenarh and R. Appel, 2. Natwrforsch., 1976, 31b, 902. D. L. Wagner, H. Wagner, and 0. Glemser, Chem. Ber., 1976, 109, 1424. 83 Elements of Group VI 247 0 0 XSY0 NSH0 N ' \NMe MeN / " oVo-Ag+ /\ I II N N + Me1 __* 11 I + I II (19) o=s c-0 o ~ s \ N / s ~ ~ M e 2 S s=o / I NN/ \NMe, F' XN' \NMe, F at an ammonia concentration of 10 moll-l. Under these conditions, yields of 8.2, 5.6 and 2.1% (based on S) for S4N2, S7NH, and S4N4, respectively, were Thiotrithiazyl chloride has been shown to form 1 : 1 adducts with CuCI,, NiCl,, CoCl,, SbC13, BiC13, ICl, and ICI,; it also forms a 2: 1 adduct with SbCI,. The adducts are ionic.85 Bromine has been shown to react with S4N4 in solution in CS, or CCl, to give thiodithiazyl dibromide, whereas iodine, under the same conditions, gave trithiazyl iodide.86 A crystal-structure determination has been carried out on the compound S4N42GH8, in which the organic components are each linked to two sulphur atoms on the S4N4 ring" (Figure 3). N ( 2) Figure 3 The molecular structure of S4N42C7H,; S(1)-N(l), 1.632; S(l)-N(2), 1.613; (Reproduced by permission from 2. anorg. Chem., 1976, 420, 155) S(2)-N(1), 1.623; S(2)-N(1), 1.616; S(1)-C(l), 1.852; S(2)-C(2), 1.849A The direct synthesis of the S4N3 ion from S4N4 has been described; when sodium azide and S4N4 are stirred together in ethanol, N2 gas is evolved, elemental sulphur is precipitated, and a deep orange solution containing Na' S4N3 is formed [equation (20)].88 This synthetic route provided some support for the 84 L. Niinisto and R. Laitinen, Inorg. Nuclear Chem. Letters, 1976, 12, 191. 8s R. C. Paul, R. P. Sharma, and R. D. Verma, Indian J. Chem., 1976, 14A, 48. " G. Ertl and J. Weiss, Z. anorg. Chem., 1976, 420, 155. Y. Monteil and H. Vincent, Z. Naturforsch., 1976, 31b,673. J. Bojes, P. M. Boorman, and T. Chivers, Inorg. Nuclear Chern. Letters, 1976, 12, 551. 88 248 Inorganic Chemistry of the Main- Group Elements proposed bicyclic structure of S4N3, which has now been verified by an X-ray structure determination of [R,N]’[S,N,]-, where R = n-C,H9 (Figure 4). The average value of the S-N bond lengths (163pm) corresponds to that in S,N, (162pm) and S4N50- (162pm); however, a significant deviation is seen in the Figure 4 The structure of the [S,N,]- ion (distanceslpm) (Reproduced by permission from Angew. Chem. Internat. Edn., 1976, 15, 379) maximum difference between the S - - * S distances. Bridging of the fifth tetra- hedral edge by a negatively charged nitrogen atom in the anion largely equalizes the S - - * S distances, so that approximately equal interactions are postulated between all sulphur atoms.” The solubilities of heptasulphur imide in eleven organic solvents have been measured.’’ S7NH has been found to react with SOClz to give colourless crystals of (S,N),SO, for which i.r., Raman, and mass spectral data have been reported. The data indicate that the geometry at the nitrogen atom is planar.’l The ring-closing properties of chlorosulphonyl isocyanate (29) have been investi- gated by studying its reaction with the silicon-nitrogen compound (30). Com- pound (31) was thought to be the product of the reaction, and its reaction with PC15 gave (32), the chlorine atom of which may be replaced by F or NMe, on reaction with NaF or Me,SiNMe,, respectively .’ , Sodium dicyanamide has been shown to react with thionyl chloride to give the cyclic compound (33).93 A crystal structure determination of dimethyl 1,2,5,6-tetrathia-3,4-diazacyclo- heptane-3,4-dicarboxylate (34) has shown that the compound exists in a twist conforma tion .94 The double ring compound (35) has been prepared by the reaction of sulphur 89 W. Flues, 0. J. Scherer, J. Weiss, and G. Wolmershauser, Angew. Chem. Internat. Edn., 1976, 15, 379. S. Hamada, Y. Kudo, and M. Kawano, Bull. Chem. Soc. Japan, 1975, 48, 2963. 91 R. Steudal and F. Rose, 2. Natwrforsch., 1975, 30b, 810. 92 H. W. Roesky, and H. Zamankhan, Chem. Ber., 1976,109, 2107. 93 G. Voss, E. Fischer, G. Remborg, and W. Schramm, Z. Chem., 1976, 16, 358. 94 K. H. Linke and H. G. Kalker, Cheni. Ber., 1976, 109, 76. Elements of Group VI 249 Me I Me, , OSiMe, I +Me,SiCI (21) ,N-SiMe, >N-< 0 N II Cl--S-N=CkO + 0-C Me C1 /N-c\ Me 11% o=C N ‘N-S’ 0 c1 / N-CxN NaN(CN), + SOCl, - CIS \N=C/ c1 250 Inorganic Chemistry of the Main-Group Elements dichloride and (36). A range of methylsilane derivatives OC-NMe-CO-NMe- S02-NnSi(Me)4-n, for n = 2, 3, and 4, may be readily prepared from the reaction of (36) and Me,SiCl,, MeSiCl,, or SiC1,.95 Two routes have been described for the preparation of 1 h4,2,4,3h 5-thiadiaza- phosphetidine (37), a compound containing a sulphur-nitrogen-phosphorus four-membered ring.96 NNSiMe3 Me,S=N--SiMe, + P 'N(SiMe,), SiMe, \ , A , /NSiMe, MeS P (24) \N' \N(SiMe,), I /NSiMe, / \NSiMe, Me2!3=NSiMe, +(Me,Si),N-P SiMe, Sulphur-Oxygen Compounds.-The crystal structure of cyclo-octasulphur oxide has been determined. The molecules consist of crown-shaped S, rings with axially bonded oxygen atoms (38). The S-S distances vary between 2.00 and 2.20& and the S-0 distance is 1.483 A; a strong intermolecular S * + - 0 interaction was po~tul ated.~~ The first complex of sulphur monoxide (39) has been synthesized by two different routes [reactions (25) and (26)]. It is thought that the structure of (39) will be similar to that of (40), whose structure has been determined. The iridium 95 H. W. Roesky and H. Zamankhan, 2. Nururforsch., 1976, 31b, 1048. R. Appel and M. Halstenberg, Angew. Chem. Internat. Edn., 1975, 14, 769. P. Luger, H. Bradaczek, P. Steudel, and M. Rebsch, Chem. Ber., 1976, 109, 180. 96 97 Elements of Group VI 25 1 atom is co-ordinated to four phosphorus and two sulphur atoms in a distorted octahedral structure. As in the S202 complex, an C S single bond is present, while the S-0 bond, according to the i.r. spectrum, exhibits double-bond character .98 The Raman spectrum of matrix-isolated S20 has been observed by preparing relatively large amounts by direct synthesis from thionyl chloride and Ag,S. The self decomposition of S,O is thought to take place by a bimolecular reaction with itself, possibly through a complex (4'1), which may explain why the observed products are S, and / O S--s I I I 1 S 7 - O A paramagnetic ion attributed to S,O- has been observed by e.p.r. spectra when H2S and SO, are allowed to react on MgO at 25°C. The proposed mechanism for the formation of S20- involves the reaction of elemental sulphur, as S,, with oxide ions of the MgO surface.'" The photoelectron spectra of H2C=S=01" and HN=S==O have been recorded and the ionization energies of X=%O derivatives compared.lo2 1.r. spectra of SO, in various matrices (Ar, N,, Xe) have been recorded at low temperatures. Several isotopic species in their natural abundances were detected, and a vibrational analysis was carried A blue, glassy solution has been observed on 7-irradiation of SO, in 2-methyltetrahydrofuran at -196 "C. Since the monomer radical anion of SO, is colourless, the absorption spectrum of the blue solution was attributed to the dimer or trimer radical anion.'04 The interaction of SO, with arsenopyrite in the temperature range 300-750 "C has been investigated, using several techniques. The reaction is complex, with different sublimates being observed at various ternperat~res.~'~ The influence of inert diluents on the rate of oxidation of SO, over a commercial vanadia catalyst has been studied.'06 with excess NH3 was warmed, it produced (NH3),,SO2 at -90 "C. This adduct decomposes near -50 "C into NH3,S02, which is yellow. With excess SO2, only NH,,SO, appears at -150 "C. If H20 is present in the matrix, (NH3)2,S02 is converted (at -80 "C) into ammonium sulphite, which is stable to room temperature; with less than the stoicheiometric When a low-temperature matrix of SO, G. Schmid and G. Ritter, Angew. Chem. Internut. Edn., 1975, 14, 645. S. Y. Tang and C. W. Brown, Inorg. Chem., 1975, 14, 2856, loo M. J. Lin and J. H. Lunsford, J. Phys. Chem., 1976, 80, 635. lo' E. Block, H. Block, S. Mohmad, P. Rosmus, and B. Solouki, Angew. Chem. Internut. Edn., 1976,15, lo* B. Solouki, P. Rosmus, and H. Bock, Angew. Chem. Internut. Edn., 1976, 15, 384. lo3 D. Maillard, M. Allavena, and J. P. Perchard, Spectrochim. Acta, 1975, 31A, 1523. lo4 0. Ito, S. Kuwashima, and M. Matsuda, Bull. Chem. Soc. Japan, 1976, 49, 327. lo6 K. K. Rungta, R. R. Hudgins, and P. L. Silveston, Cunad. J. Chem., 1976, 54, 665. 99 383. L. E. Derlyukova, B. M. Tarakanov, and V. I. Evdokimov, Russ. J. Inorg. Chem., 1976, 21, 328. 105 252 Inorganic Chemistry of the Main-Group Elements amount of H,O, the final product is the pyros~lphite.'~' Water vapour has also been found to increase the rate of reaction in the system H20-S02-N0,-NH3. In the presence of nitrogen oxides and water vapour, the oxidation of SO2 occurs, which results in the formation of ammonium su1phate.lo8 The reactions of a large number of metals with the mixed non-aqueous system dimethyl sulphoxide-sulphur dioxide have been investigated, and the formation of either pyrosulphates or sulphates has been Phase studies indicated the existence of a 1:l adduct of DMSO and SO,, of m.pt. -38"C, which is considered responsible for the solution of metals in the system (Scheme 1). Me,SO- --SO, + M -+MSO, J li MS,O, a MS20, MSO, Scheme 1 Reagents: i, Me,SO; ii, SO,; iii, 2Me,SO Complete solid-state Raman and i.r. spectra have been obtained for the 1 : 1 complex between SbFs and SO,. The three fundamental vibrations ascribed to the SO, moiety of F,SbOSO were assigned to Raman bands at 1320, 1100, and 539 cm-l; these are shifted by approximately -15, -45, and -115 cm-' from the values for the equivalent modes in free The assignment of a methylated sulphur dioxide structure MeO=S=O' to the species present in MeF-SbF5-SO2 solutions and the precipitation of a salt of MeO=S=O' upon addition of SO, to MeF-SbF,-SO2C1F have been reported.'" The results indicate that methyl and primary cations cannot be formed in SO, solutions because they react with SO,, and not with SbF, (as previously thought). Silylated iminophosphoranes of the type (42) have been shown to react with SO,; insertion of SO, into the silazane bond occurs, to give (43). In the case of the bifunctional methyIene(bisiminophosphorane) (44), silylated sulphuric acid splits off, and the phosphaza-sulphone (45) is formed.'', R'R;P=N--SiMe, +SO3 __* RIR;P=N-SO,-O-SiMe, (42) R' (27) =Ph or Me R2 =PhorMe (43) Ph,P PPh, 2.T II II + SO, - Ph2P It BPh, +(Me3SiO),S02 (28) N N N I I (44) Me,Si SiMe, ' S / 0 2 (45) lo7 I. C. Hisatsune and J. Heicklen, Canad. J. Chem., 1975, 53, 2646. lo9 W. D. Harrison, J. B. Gill, and D. C. Goodall, J.C.S. Chem. Comm., 1976, 540. 'lo D. M. Byler and D. F. Shriver, Inorg. Chem., 1975, 15, 32. '11 P. E. Peterson, R. Brockington, and D. W. Vidrine, 1; Amer. Chem. Suc., 1976, 98, 2660. '12 R. Appel, I. Ruppert, and M. Montenarh, Chem. Ber., 1976, 109, 71. J. Haber, K. Malysa, J. Pawlikowska-Czubak, and A. Pomianowski, 2. anurg. Chem., 1975,418, 179. 108 Elements of Group VI 253 Oxyanions of Sulphur. The thermal dissociation of LiHSO, in the temperature range 80-400°C at various air pressures has been in~estigated."~ The Raman tensors for the nine internal vibrations of Na,SO, (V) have been computed, and the derived relative intensities compare well with the experimental values meas- ured on an oriented single The structure of KHSO, at room tempera- ture has been refined. Differences from previous studies were observed in the hydrogen-bonding features of the polymeric HSO, chain that is considered to play an essential role in the conduction process and in the polymorphic behaviour of KHS04. It was suggested that these differences might be related to some degree of substitution of (HS04)- ions by (SO:-,H+) groups within the polymeric chair^."^The crystal structure of the room-temperature modification of caesium sulphate, p -Cs,SO,, has been deterrnined.ll6 The sulphate tetrahedra are almost regular, with an average S O distance of 1.477A. The preparation, thermal analysis, and X-ray, Raman, and i.r. spectra of the sulphites and sulphite hydrates of Ca, Sr, Ba, Pb, and Cd have been described.'17 The co-ordination of the sulphite ion was obtained from the frequency of the S-0 stretching modes, and the decomposition of the compounds was also studied. The solubilities of gypsum, a -hemihydrate, and y-anhydrite in HCI solutions have been measured at 25 "C. In solutions containing 0-11.4% HCl the stable solid phase is gypsum, whereas at higher concentrations y-anhydrite is stable.ll8 Single-crystal Raman spectra of (NH4)2S04 have been rep~rted.~~' The photolysis of aqueous solutions of peroxydisulphate in situ has been investigated as a source of radicals for e.s.r. studies. This initiating system was found to be quite effective in that the SO,* so produced reacts readily with a variety of solutes, and the successful detection of a number of new radicals was possible.'" The i.r. spectra of IOS02F, BrOS02F, HOS02F, DOS02F, Br,SO,F, and C102S03F have been recorded at 80 K. Detailed vibrational assignments and structural conclusions were presented.lZ1 The crystal structure of Na3[ON(S03),],3H20 has been determined.12, The [ON(S03)2]3- anion (46), which contains a crystallographic mirror plane passing through the NO group, has a pyramidal co-ordination at nitrogen and an N-0 bond length of 1.427 A; both features distinguish it from the radical nitrososul- phonate, where the N-0 bond length is 1.28A. A thermally populated triplet excited state of the triclinic form of (KSO,),NO, has been detected by e.p.r. and static susceptibility measurement~.~'~ The crystal structure of HK,NO,S, has been redetermined from three-dimensional neutron- diffraction data.124 The reaction of SO2 with molybdate ions in aqueous solution V. G. Vasil'ev, V. S. Markov, 0. N. Utkina, and B. V. Shulyatikov, Russ. J. Inorg. Chern. 1975, 20, 1593. S. Montero, Spectrochirn. Acta. 1976, 32A, 843. A. G. Nord, Acta Chem. Scand. (A)., 1976, 30, 198. H. D. Lutz and S. El Suradi, 2. anorg. Chem., 1976, 425, 134. V. P. Kruchenko and V. A. Beremzhanov, Russ. J. Inorg. Chem., 1976, 21, 152. R. L. Carter, Spectrochirn. Acta, 1976, 32A, 575. 113 11' F. Payan and R. Haser, Acta Cr y s t . , 1976, B32, 1875. 117 118 lz0 0. P. Chawla and R. W. Fessenden, J. Phys. Chern., 1975, 79, 2693. lZ1 W. W. Wilson, J. M. Winfield, and F. Aubke, J. Fluorine Chern., 1976, 7, 245. J. S. Rutherford and B. E. Robertson, Inorg. Chem., 1975, 14, 2537. B. D. Perlson and D. B. Russell, Inorg. Chem., 1975, 14, 2907. 122 123 124 P. G. Hodgson, F. H. Moore, and C. H. L. Kennard, J.C.S. Dalton, 1976, 1443. 254 Inorganic Chemistry 0 of the Main-Group Elements has been used to prepare crystals of (NH4)4S2M05021,3H20 [see equation (29)]. In the polyanion, five MOO, octahedra form a Mo502' ring, with two SO3 trigonal pyramids attached to the ring from above and 5MoOi- + 2S0, + 6H' + S,Mo,O:; + 3H,O (29) The oxidation products when S20z- is used as a titrant against lead tetra- acetate in glacial acetic acid have been identified as di- and tetra-thionates, whereas sulphate is the end product in titrations using S20~-. 12" The disproportionation of thiosulphate, trithionate, tetrathionate, and sulphite in acid solutions has been studied at moderate temperatures. Thiosulphate hardly decomposes in the absence of sulphuric acid, even at 150°C, but decomposes readily in the presence of sulphuric acid at 70 "C, forming sulphur, tetrathionate, and sulphite. Trithionate decomposes to thiosulphate and sulphate at 70 "C, whereas tetrathionate decomposes only above 130 "C. Sulphite undergoes dis- proportionation, giving thiosulphate and sulphate at 150 "C, and then sulphur and sulphate, accompanied by the intermediate formation of tefrathi~nate."~ An intramolecular exchange of sulphur in solid Na2SZ03 has been confirmed and improved rate constants have been measured.'28 The mechanism of decom- position of dithionite in aqueous solutions has been studied. The decomposition can be described by the equations (30) and (31). The final composition of the 2H,S20, + S + 3s 0, + 2H,O (30) 3H,S20, * H,S + 5s0, + 2H,O (3 1) products is, however, the result of parallel and consecutive reactions of H,S and S with SO, which yield thiosulphate and polysulphides and pol ythi onate~.'~~ Factor-group and site-group analyses have been carried out on potassium dithion- ate, for which i.r. and Raman spectra were obtained which could be unambigu- ously inter~reted.'~' Results on the decomposition of the S,Oi- ion in highly K. Y. Matsurnoto, M. Kato, and Y. Sasaki, Bull. Chem. SOC. Japan, 1976, 49, 106. K. A. Idriss, I. M. Issa, and M. S . El-Meligy, Indian J. Chem., 1976, 14A, 195. lZ7 T. Mizoguchi, Y. Takei, and T. Okabe, Bull. Chem. SOC. Japan, 1976, 49, 70. 12* L. H. McAmish and F. J. Johnstone, J. Inorg. Nuclear Chem., 1976, 38, 537. 129 V. Cermak and M. Smutek, Coll. Czech. Chem. Comrn., 1975, 40, 3241. P. Dawson, M. M. Hargreave, and G. R. Wilkinson, Spectrochirn. Acta, 1975, 31A, 1533. Elements of Group VI 255 alkaline conditions have been pre~ented.'~' The rate of disappearance of S,O;- was found to be proportional to [OH-], and it was also possible to differentiate between two modes of decomposition: (i) homolytic cleavage of S20g-, to give SO,. radicals, and (ii) alkaline hydrolysis, to give HSO, and SO,"-. Some thermodynamic functions at saturation of several metal sulphates in H2S04 and D2S04 have been calculated from solubility data.132 The kinetics of dissolution of iron(x1) sulphide in aqueous sulphuric acid have been The behaviour of various solutes in chlorosulphuric acid has been investigated conduc- tometri~a1ly.l~~ A potentiometric study of the system (32) in sulfolane has enabled the dissociation constant of the reaction (33) to be determined.'" The rate of decomposition of trifluoromethanesulphonic acid in water and its reactivity towards various metals have been in~estigated.'~~ AgCl + SO, + e- + Ag + SO,Cl- SO,Cl- + SO, + C1- (32) (33) The behaviour of some iodine compounds in disulphuric acid has been studied. IPO, and I(OAc), form I(HSO,)g ions, whereas I(S03X)3 forms I(S03X)i, but IOAc, IBr, ICN, and I N03 form paramagnetic blue solutions, due to 1; ions.13' The kinetics of oxidation of iodide ion by H2S05 and H,PO, have been investi- gated. A mechanism consistent with nucleophilic attack by I- on the external peroxidic oxygen, leading to breaking of the oxygen-oxygen bond, was pro- Some phase diagrams and systems which have been studied in this area are collected in Table 2.139-'53 Sulpltides.-Hydrogen Sulphide. The far4.r. rotational absorption spectra of H2S, SO,, and NO, have been recorded between 10 and 40cm-' at a resolution of 13' U. C. Singh and K. Venkatarao, J. Znorg. Nuclear Chem., 1976, 38, 541. 132 W. L. Marshall, J. Znorg. Nuclear Chem., 1975, 37, 2155. 133 P. H. Tewari, and A. B. Campbell, J. Phys. Chem., 1976, 80, 1844. 134 R. C. Paul, D. S. Dhillon, and J . K. Puri, Indian J. Chem., 1975, 13, 1058. 136 L. Fabes and T. W. Swaddle, Canad. J. Chem., 1975,53,3053. 13' A. Bali and K. C. Malhotra, J. Znorg. Nuclear Chem., 1976, 38, 411. 13' F. Secco and M. Venturini, J.C.S. Dalton, 1976, 1410. 140 S. P. Sirotinkin, A. N. Pokrovskii, and L. M. Kovba, Russ. J. Znorg. Chem., 1976, 21, 3425. 14* V. L. VoIkov, E. I. Andreikov, L. L. Surat, and A. A. Fotiev, Rus , J. Inorg, Chem., 1976, 21, 415. 14* G. A. Bukhalova, E. L. Kozachenko, D. V. Senentsova, and V. V. Kepopyan, Russ. J. Znorg. Chem., 143 G. P. Kuznetsova, G. A. Lovetskaya, V. M. Presnyakova, B. D. Stepin, and T. G. Smirnova, Russ. J. P. Pierens, Y. Auger, J. C. Fischer, and M. Wartel, Canad. J. Chem., 1975, 53, 2989. 135 D. L. Motov and S. A. Kobycheva, Russ. J. Znorg. Chem., 1976, 21, 375. 139 1975, 20, 776. Inorg. Chem., 1975, 20, 1410. I. F. Poletaev and L. V. Krasnenkova, Rum. J. Inorg. Chem.; 1975, 20, 1250. 14' B. A. Berenzhanov and V. P. Krudenko, Russ. J. Inorg. Chem., 1975, 20, 1746. 146 I. F. Poletaev, A. P. Lyudomirskaya, and N. D. Tsiklina, Russ. J. Znorg. Chem., 1975, 20, 1742, 14' A. S. Moshinskii, Russ. J. Znorg. Chem., 1975, 20, 1721. 14' A. G. Bergman, E. Ismanov, and G. A. Bukhalova, Russ. J. Znorg Chem., 1976, 21, 154. 1 4 ' K. Mocek, E. Lippert, and E. Erdos, Coll. Czech. Chem. Comm., 1976, 41, 675. Is' J . Balej and V. G. Shevchuk, Coll. Czech. Chem. Comm., 1975, 40, 3290. lS1 J. Balej, M. Cizek, and M. Thumova, Coll. Czech. Chem. Comm., 1976, 41, 507. 15' K. Mocek, E. Lippert, and E. Erdos, Coll. Czech. Chem. Comm., 1976, 41, 1831. 153 A. M. Golub, S. S. Butsko, and L. P. Dobryanskaya, Russ. J. Znorg. Chem., 1975, 20, 1510. 144 256 Inorganic Chemistry of the Main- Group Elements Table 2 Some phase systems involving System Ref. Hf02-Na2S04-H2S04-H20 139 Li2S0,-R,(SO,), (R =Pr, Nd, or Yb) 140 K2S04-c~ -VOSO, 141 Li+, Rb+, T1+ 1) SO;- 142 Rb2S04-H20 143 CS~SO, - R~~SO~- H~O 143 Na+, Rb+ 11 NO,, SO:-, H2 0 144 Cs+, Na+ (1 NO;, SO$-, H20 144 CaS0,-HN0,-H2S04-H20 145 oxyanions of sulphur System CaCO, +Na2S0, Ca2+, Zn2+ 11 C1-, SO;-, H2 0 Na+, K+, Ag+ 11 SO$- Na+, Rb+, Ag+ 11 SO:- Ca(OH), +Na2S0, % CaSO, +2NaOH NH;, Na+ 11 SO:-, S20g-, - H20 Na2S03 +Ca(OH), % 2NaOH +CaSO, CuI-Na2S203-H20 CaSO, +Na,CO, (NH,)2S04-C~2S0,-H20 Ref . 146 147 148 148 149 150 15 1 152 153 0.05 cm''. Assignments were suggested for some of the observed lines of H2S and NO2, and the SO, spectrum was compared with a computed spectral The surface tension of H2S-saturated water has been measured at pressures up to 3.0 MPa and at temperatures in the range 25-130 "C. Monolayer coverage of the aqueous solution by H2S occurred at about one-half the saturation pressure of liquid H2S at a given temperat~re.'~~ Yields of hydrogen and sulphur have been determined in the rare-gas-sensitized radiolysis of hydrogen ~u1phi de.l ~~ The rate of formation of S2 from shock-heated H2S has been measured by means of the U.V. absorption technique in the temperature range 2380-3000K. A mechanism for the formation of S2 was proposed and the influence of impurities on its rate of formation sf~died.'~' The behaviour of an aqueous solution of H2S when submitted to ultrasonic irradiation has been investigated. The formation of molecular hydrogen and the appearance of colloidal sulphur was observed; the former was explained by a mechanism involving direct dissociation of H2S, which is probably concurrent with oxidation of the H2S? The reaction of GeBr, with H2S in carbon disulphide has been shown to give Ge,S,Br,, the first sulphide halide of germanium. A complete X-ray structure determination showed the molecule to have an adamantane-like structure, with significant deviations from Td symmetry in the solid Good yields of trifluoromethyltrisulphane may be obtained by allowing a mixture of an excess of H2S with chloro(trifluoromethy1)disulphane to warm slowly from -196 to 25 "C over a period of eight hours. The trifluoromethyltrisulphane was recovered, using low-temperature vacuum distillation. The excess of H2S is used to minimize the competing reaction (34).I6O The ammineruthenium complex of H2S, containing the ion [ Ru( NH~) ~H~S] ~+, has been characterized, and salts containing it have been prepared. The complex is readily oxidized, and, even in the solid, it decomposes to liberate hydrogen.161 CF,SSCl +CF3SSSH + CF,S5CF, + HCl (34) lS4 J. W. Fleming, Spectrochim. Acta, 1976, 324 787. 15' G. G. Strathdee and R. M. Given, J. Phys. Chem., 1976, 80, 1714. lS6 M. Forys, A. Jowko, and I. Szamrej, J. Phys. Chem., 1976, 80, 1035. T. Higashihara, K. Saito, and H. Yamamura, Bull. Chem. SOC. Japan, 1976, 49, 965. G. Cawet, C. M. Costa, H. Knoche, and J. P. Longuemard, Bull. SOC. chim. France, 1976, 45. 157 158 lS9 S. Pohl, Angew. Chem. Internat. Edn., 1976, 15, 162. 160 C. A. Burton and J. M. Shreeve, Inorg. Nuclear Chem. Letters, 1976, 12, 373. C. G. Kuehn and H. Taube, J. Amer. Chem. Soc., 1976,98, 689. Elements of Group VI 257 Polysulphides. The reactions of lithium and sodium with sulphur in liquid am- monia have been studied. The thermal behaviour of the polysulphides was also investigated by means of thermogravimetric and differential thermal analyses.162 The enthalpies of formation of both the sulphides and polysulphides of lithium and sodium have been determined in 0.1 N-H,SO, by reaction ca1orimet1-y.~~~ The crystal structures of two compounds, K2S,164 and T12S5,16' both containing the pentasulphide ion, have been reported. Both studies show the ion to exist as a contorted but unbranched chain; bond lengths and angles are given in Table 3. Table 3 Bond lengths and angles for the Sz- ion K2S5 Tl2S5 S(l)--s(2) 2.037 8, 2.06 8, W--S(3) 2.074 8, 2.16 8, S(3)--S(4) 2.075 8, 2.06 8, S(4)--S(5) 2.050 8, 2.08 8, a 1)4(2)--s(3) 109.7 O 107.6 O LS(3)-S(4)-S(5) 108.7 O 108.2 O LS(2)-S( 3)-S(4) 106.4 O 108.8 O Raman studies of the sodium polysulphides Na2S,, where x = 2, 3,4, or 5, have been carried out. A complete vibrational assignment was achieved for Sg-, whereas exact analytical characterizations were achieved for S;-, Sa-, and Sg-, but with less complete vibrational assignments. An instability of Sg- and Sz- in the corresponding solid polysulphide was observed; at moderately high temperatures the former disproportionates to S:- and Sg-, whereas the latter disproportionates to S$- and elemental sulphur.166 A similar study of the potassium polysulphides K&, KzS4, K2S5, and KzS6 showed that K& undergoes a transformation into K2S5 and sulphur in the solid state at temperatures as low as 150 "C. The assignment of C2, symmetry for S;- and C2 symmetry for Sa- was made.167 The ion Sz- in the polysulphide BaS316* was also assigned C2, symmetry. Other Sulphides. The phase systems As,S,-N~,S,~~' Ag-Bi-S,17' and Ga-Sb-S17' have been studied. The thermal dissociation of CS2 in CS2-Ar gas mixtures has been investigated for gas pressures between 10 and 40 Torr and temperatures up to 2400 K.172 The time-resolved emission spectrum of gaseous CS2, excited by an N2 laser, and its temperature dependence have been 0bser~ed.l ~~ 16' J. M. Letoffe, J. M. Blanchard, and J. Bousquet, Bull. SOC. chim. France, 1976, 395. la B. Kelly and P. Woodward, J.C.S. Dalton, 1976, 1314. 16' B. Leclerc and T. S. Kabre, Acta Cryst., 1975, B31, 1675. 166 G. J. Janz, J. R. Downey, E. Roduner, G. J. Wasilczyk, J. W. Coutts, and A. Eluard, Inorg. Chem., 1976, 15, 1759. 167 G. J. Janz, J. W. Coutts, J. R. Downey, and E. Roduner, Inorg. Chem., 1976, 15, 1755. G. J. Janz, E. Roduner, J. W. Coutts, and J. R. Downey, Inorg. Chem., 1976, 15, 1751. 169 N. I. Kopylov and S. M. Minkevich, Russ. J. Inorg. Chem., 1975, 20, 1744. 170 I. S. Kovaleva and S. P. Chukov, Russ. J. Inorg. Chem., 1975, 20, 1362. 17' P. G. Rustamov and D. S. Azhdarova, Russ. J. Inorg. Chem., 1975, 20, 957. 172 T. C. Peng and H. V. Lilenfeld, J, Phys. Chem., 1975, 79, 2203. 173 A. Matsuzaki and S. Nagakura, Bull. Chem. SOC. Japan, 1976, 49, 359. J. M. Letoffe, J. Thourey, G. Perachon, and J. Bousquet, Bull. SOC. chim. France, 1976, 424. 163 168 258 Inorganic Chemistry of the Main-Group Elements The preparation and properties of phosphorus sulphides and selenides have been reviewed, the exact number of compounds being determined from the phase diagram. Phosphorus does not react with tellurium, and the P-S-Se ternary diagram shows no P-S-Se A kinetic study of the reaction of a series of symmetrical alkyl disulphides with Ph3P in 50% dioxan-H,O has been reported. The reaction results in reduction of the disulphide to yield the corresponding alkanethiol and triphenylphosphine The ternary sulphides K2Ag4S, and Rb,Ag& have been synthesized by fusion of alkali-metal carbonates and sulphur with silver. A new layer structure type, with a slightly distorted triangular co-ordination of sulphur around the silver atoms, was '19Sn Mossbauer spectra have been recorded for a number of ternary sulphides isolated from the Na,S-SnS,, BaS-SnS,, and PbS-SnS, A crystal structure determination of Cs4Ge,Slo,3H,0, prepared by heating alkali-metal sulphides with excess GeS, in aqueous solution, has shown the compound to form adamantane-like Ge,S:& ions in the solid state as well as in aqueous solution. I n the ion the terminal Ge-S bond lengths (2.108A) are significantly shorter than the bridging Ge-S bonds (2.236 A).178 The crystal structures of the a- and p-forms of SnSI, have been rep~rted.'~~ Fe,SiS, and Fe,GeS, have been shown to have the olivine structure, with the space group Pnmu.180 A crystal structure determination has shown that 5-chloro-l-oxa-4,6- dithia-5-stibocan possesses an eight-membered ring, with the chair-chair confor- mation and a transannular Sb-0 interaction."' A new isomeric form of arsenic sulphide, uir.As4S4 (11), has been prepared by melting the pure elements As and S in the temperature range 500-6OO0C, and its crystal structure has been deterrnined.l8' The ternary sulphide KCeS, has been shown to have the rhombohedra1 a -NaFeO, structure.lg3 A crystal structure determination has shown that in the compound CeBiOS, the cerium atom is co-ordinated to four oxygen and four sulphur atoms, with Ce-0=2.37 and Ce-S = 3.10 A. Bismuth is co-ordinated to six sulphur atoms, forming an irregu- lar square-based pyramidal octahedron.lg4 In an X-ray diffraction study of the sesquisulphides Ln2S3 (Ln = La to Dy), diffraction patterns similar to (but not identical with) those of a -Ln2S3 were obtained;lg5 new modifications have also been found as a result of applying high pressures and temperatures.lg6 Quenching from conditions of high temperature and high pressure has also given three new modifications of the ternary sulphide GdYbS,.lS7 M,Mo,S, compounds (M = 1'4 Y. Monteil and H. Vincent, 2. Naturforsch., 1976, 31b, 668. 175 L. E. Overman and E. M. O'Connor, J. Amer. Chem. SOC., 1976, 98, 771. 177 R. Greatrex, N. N. Greenwood, and M. Ribes, J.C.S. Dalton, 1976, 500. 'la S. Pohl and B. Krebs, Z. anorg. Chem., 1976, 424, 265. 179 N. H. Dung and F. Thevet, Acra Cryst., 1976, B32, 1108. "' M. Drager, Z. anorg. Chem., 1976, 424, 183. lS2 A. Kutoglu, 2. anorg. Chem., 1976, 419, 176. la3 C. M. Plug and G. C. Verschoor, Acta Cryst., 1976, B32, 1856. '=R. Ceolin and N. Rodiev, Acra Cryst., 1976, B32, 1476. la' A. A. Eliseev, A. A. Grizik, V. A. Tolstova, and G. P. Borodulenko, Russ. J. Inorg. Chem., 1975,20, W. Bronger and C. Burschka, 2. anorg. Chem., 1976, 425, 109. 176 H. Vincent, E. F. Bertaut, W. H. Baur, and R. D. Shannon, Acta Cr y s t . , 1976, B32, 1749. 1752. K. J. Range and R. Leeb, Z. Nafurforsch., 1975, 304 889. la' J. B. Clarke and K. J. Range, 2. Narurforsch., 1975, 304 896. Elements of Group VI 259 Ni, Co, Cr, or Fe) have been shown to be isostructural with N~MO~S,,~~' and it has been shown that the same structure is adopted by both Pb,Mo3S, and PbxMo3Se4.1g9 The crystal structure of CO~. ~, T ~S~ has been refined.lgO 3 Selenium The Element.-The direct determination of very small amounts of selenium in copper and copper salts has been investigated. A mixture of equal volumes of nitric, hydrochloric, and perchloric acids was used to dissolve the copper and to oxidize the selenium to the 4+oxidation state. A gas-chromatographic method, using an electron-capture detector, can then be used to determine the selenium in copper in amounts as low as 0.005 pgg-l.191 The sublimation of selenium (and tellurium) has been found to be faster in the presence of aluminium or gallium halides than in the presence of an inert gas. This effect was explained by catalysis caused by interaction of the lone pairs of selenium and tellurium with the The reaction of elemental selenium with sulphite at different pH has been investigated. The reaction is complex, with the intermediate formation of selenanemonosulphonic acids and selenopolythionates being observed. The final reaction products are sulphate and sulphur, the selenium being recovered in almost 100% yield.193 Selenium-Halogen Compounds.-An n.m.r. study has shown that the fluorine exchange in SeF, is suppressed at -140°C in methyl fluoride solution. It was found that SeF, is a monomeric species under these conditions.194 Liquid-phase Raman spectra of XCF, (X = S or Se) and i.r. spectra of gaseous SeCF, have been recorded, and assigned on the basis of C2v A large number of new perfluoroalkyl derivatives of SeF, and SeF, have been prepared. The neutral perfluoroalkyl-selenium(1v) derivatives have structures based on a trigonal bipyramid, with the perfluoroalkyl group(s) preferentially occupying equatorial positions. The vibrational spectrum of CsF,C2F,SeF3 is consistent with an ionic formulation, and the spectra of the pentafluoride adducts suggest a substantial ionic contribution, with anion-cation i ntera~ti 0n.l ~~ The stabilization and characterization of the monochlorodiphenylselenonium ion, Ph2SeC1', in the form of its adducts with SbCl, and SnCl,, has been reported. The adducts were assigned ionic structures on the basis of i.r. and conductance data.19' The PC1,-SeCl, phase diagram has been studied, and a 1 : l compound that is stable up to 280°C was f0~nd.l ~' Potassium fluoroselenate has been prepared by the reaction of selenium dioxide "' J. Guillevic, 0. Bars, and D. Grandjean, Acf a Crysf., 1976, B32, 1338. 190 M. Danot and R. Brec, Acta Crysf. , 1975, B31, 1647. 19' H. Schafer and M. Trenkel, Z. anorg. Chem., 1976, 420, 261. 193 M. Schmidt and H. P. Kopp, Angew. Chem. Znremaf. Edn., 1975, 14, 638. 19' A. Haas, B. Koch, N. Weleman, and H. Willner, Specfrochim. Am, 1976, 32A, 497. 196 C. Lau and J. Passmore, J. Fluorine Chem., 1976, 7, 261. 19' R. C. Paul and K. K. Bhasin, Indian J. Chem., 1976, 144 201. 19' M. K. Chikanov, Russ. J. Inorg. Chem., 1975, 20, 118. J. Guillevic, H. Lestrat, and D. Grandjean, Acra Cryst., 1976, 832, 1342. Y. Shirnoishi, Bull. Chem. Soc. Japan., 1975, 48, 2797. 191 K. Seppelt, Z. anorg. Chem., 1975, 416, 12. 194 260 Inorganic Chemistry of the Main - Group Elements difluoride with potassium hydrogen selenate. The reaction of Se02F2with anhydr- ous nitric acid gives nitronium fluoroselenate. Both compounds were charac- terized by powder X-ray data and i.r. and Raman spectra, and the vibrational spectra of the Se0,F- anion were assigned.'99 The potassium and caesium salts of Se0,F- have been prepared by the reaction of SeO, with the appropriate fluoride in the melt and in solution in dimethyl sulphoxide and in 48% HF. The Raman and i.r. spectra of both salts were measured, and certain reassignments made of the fundamental vibrations of Se02F-. K2Se02F, was prepared for the first time by heating KSe0,F with KF at ca. 300 "C; Raman spectra indicated a pseudo-trigonal-bipyramidal structure for SeO,F;-, with CZv symmetry.200 Selenium-Oxygen Compounds.-The Raman spectra of molten and gaseous selenium dioxide are nearly identical. The number of bands is thought to indicate the existence of a temperature-dependent equilibrium of monomeric and dimeric selenium dioxide in the molten and the gaseous states. A chain structure (as in the crystalline state) could not be found, and an oxygen-bridged, planar ring structure was proposed for the dimer.201 The solid-state reaction of SeO, with V,O, has been studied by X-ray diffrac- tion methods. In an inert atmosphere the reaction product was the dark red compound Se,V,09, which is not isostructural with the corresponding tellurium analogue and which decomposes into its component oxides above 400 OC."' The formation of 1 : 1 complexes between SeO, and SeOCl, and C1-, Br-, and I- has been reported. The stability constants and nature of the complexes were correlated with those of SO, and SOCl2, and the role of DMSO as solvent was discussed.203 The reaction of indium selenate with potassium selenate in aqueous solution has been studied. An increase in the concentration of potassium selenate in solution leads to the formation of potassium bis(selenato)indate, KIn(SeO,),,- 4H20, which in 15% K2Se0, solution is hydrolysed to K,In(OH)(Se0,)2,H20.~~ Selenous acid is polymerized in concentrated aqueous solution, with de- polymerization taking place on dilution. A study of the acid salts formed from such solutions has indicated the presence of dimeric, trimeric, and tetrameric species. Four structures (47)-(50) were proposed for the dimer, with (48) or (49) being the most likely.205 Standard heats of formation of some gallium selenites206 and hydrogen selen- i te~''~ have been derived from heats of reaction of the salts with 20% HCl. lg9 M. Cernik and K. Dostal, 2. anorg. Chern., 1976, 425, 37. R. J. Gillespie and P. Spekkens, J. Fluorine Chern., 1976, 7, 43. H. Ziemann and W. Bues, 2. anorg. Chem., 1975, 416, 341. 200 201 202 J. C. J. Bart and G. Petrini, 2. anorg. Chem., 1976, 422, 179 203 S . Wasif and S. B. Salama, J.C.S. Dalton, 1975, 2239. 204 N. V. Kadoshnikova, E. N. Deichman, I. V. Tananaev, and Yu. Ya. Kharitonov, Russ. J. Inorg. 205 G. Narein and L. N. Shrivastava, Russ. J. Inorg. Chern., 1975, 20, 666. Chem., 1975, 20, 1150. I. V. Tananaev, A. N. Volodina, N. M. Selivanova, and N. K. Bol'shakova, Russ. J. Inorg. Chem., 1976, 21, 617. *07 I. V. Tananaev, A. V. Volodina, N. M. Selivanova, and N. K. Bol'shakova, Russ. J. Inorg. Chem., 1976, 21, 619. Elements of Group Vl 26 1 HO HO 0 * - - *HO // \ HSe-OH HO / HO 'OH.. * . 0 HO-Se \ - * * \ Se=O.*. . . ,se=o /OH O=Se / ' OH H \o . . . . H- O OH ' * * 0-Se / \ / Se=o \OH O=Se 'OH.. . . 0 (49) (50) A determination of the crystal structure has shown that, in the compound 2Ph3As0,H2Se03, two Ph3As0 units and one selenite group are linked by short hydrogen bonds. The As-0 distance is 1.64 A and the Se-0 distances are 1.69, 1.83, and 1.76A.208 The oxide CuSe205 has been shown to possess a structure characterized by zig-zag strings that are of composition (CuSe205),,, parallel to the crystal c-axis. In each string, copper is strongly bonded to four oxygen atoms in an approximately square-planar configuration. The selenium atoms have three- fold co-ordination, with two SeO, pyramids sharing a corner to form a Se,Og- group (Figure 5).209 Figure 5 Bond lengths and angles for the Se @- group (Reproduced by permission from Acta Cryst., 1976, B32, 2664) Metal Seienides.-The compounds MnGa2Se4 and MnGa2Te4 have been prepared by direct synthesis from the elements at 900--1000°C. MnGa,Se, was found to be isotypic with the compound CdGa2S4.210 Electronic and Raman spectra have been used to determine the gaseous species present in the preparation of single H. J. Haupt, F. Huber, H. Preut, and R. Menge, Z. anorg. Chem., 1976, 424, 167. 208 ' 09 G. Meunier, C. Svensson, and A. Carpy, Acta Cr yst ., 1976, B32, 2664. 'lo K. J. Range and H. J. Hubner, Z. Naturforsch., 1976, 31b, 886. 262 Inorganic Chemistry of the Main -Group Elements crystals of In,Se, by chemical transport with iodine. The species identified were 12, I, Sen ( n = 2,3,5,6,7, or 8), and In1 at temperatures above 650 “C, and pressure measurements were used to calculate the thermodynamic constants of the equilib- ria (35) and (36).,11 Knudsen effusion studies of the sublimation of polycrystalline In,Se,(s) +3I,(g) 21n1,(g) + $Se,(g) (36) GeSe, have been performed. The results demonstrate that GeSe, vapourizes congruently under the experimental conditions employed, according to the pre- dominant reaction (37) and a minor reaction (38). From these reactions, the GeSe,(s) + GeSe (g) + $Se, (g) (37) GeSe,(s) + GeSe,(g) (38) standard heat of formation and absolute entropy of GeSe,(s) were calculated to be -21.7 kcal mol-’ and 24.6 e.u., respectively.212 GeSe, has been shown to be isotypic with the high-temperature form of GeS,. The .Ge-Se bond distances were found to equal the sum (2. 36& of Pauling’s tetrahedral radii.213 Solid solutions of formula Nb,-,V,Se, ( O< x < 1) have been prepared by direct synthesis from the elements under minimum gradient conditions. Single crystals of NbSe, and VSe, were also prepared by chemical transport, using iodine as the transporting agent. Three monophasic regions were observed for x = 0 to 0.01, 0.11 to 0.2, and 0.3 to 1.0; it was proposed that vanadium substitutes for niobium in trigonal prismatic co-ordination in only the first of these regions, otherwise the vanadium goes into octahedral ~o-ordi nati on.~~~ Mixed anion systems of the tungsten dichalcogenides have been prepared. In the WS,-,Se, system there is a continuous series of solid solutions, but two monophasic regions were observed in the WSe,-,Te, and WS,-,Te, The U2S3 type of structure of Dy2Se3 has been confirmed and refined from single-crystal data.216 The crystal structures of a number of copper selenides have been re-examined, using powder X-ray diffraction data, and a set of structures have been Several phase studies of selenide systems have been published, and are col- lected in Table 4.21G225 211 J. K. Grinberg, V. A. Boriakova, V. F. Chevel’kov, R. Hillel, and J. Bouix, J. Inorg. Nuclear Chem., ‘12 E. A. Irene and H. Wiedemeier, 2. anorg. Chem., 1976, 424, 277. 214 M. Bayard, B. F. Mentzen, and M. J. Sienko, Inorg. Chem., 1976, 15, 1763. 1976, 38, 383. G. Dittmar and H. Schafer, Acta Cr yst ., 1976, B32, 2726. B. F. Mentzen and M. J. Sienko, Inorg. Chem., 1976, 15, 2198. K. J. Range and R. Leeb, Z. Naturforsch., 1976, 31b, 685. 217 R. D. Hayding and R. M. Murray, Canad. J. Chem., 1976, 54, 841. 21a P. G. Rustamov, A. Z. Gadzhieva, and B. N. Mardakhaev, Russ. J. Inorg. Chem., 1976, 21, 279. 219 D. Linke and F. Heyder, Z. anorg. Chem., 1976, 425, 155. 220 I. A. Sidorov, R. L. Magunov, 0. V. Zakolodyazhnaya, and Y. V. Belyuga, Russ. J. Inorg. Chem., 215 1976, 21, 466. V. P. Savel’ev, Z. M. Latypov, and V. P. Zlomanov, Russ. J. h o g . Chem., 1975, 20, 1119. 221 222 P, G. Rustamov and B. K. Babaeva, Russ. J. Inorg. Chem., 1975, 20, 1360. 223 Y. Monteil and H. Vincent, J. Inorg. Nuclear Chem., 1975, 37, 2053. A. A. Babitsyna, T. A. Emel’yanova, M. A. Chernitsyna, and V. T. Kalinnikov, Russ. J. Inorg. Chem., 1975, 20, 1711. 224 225 A. A. Babitsyna, M. A. Chernitsyna, and V. T. Kalinnikov, Russ. J. Inorg. Chem., 1975,20, 1855. Elements of Group VI 263 Table 4 Phase-diagram studies involving selenium System Ref. System In-Se-Sn 2 18 Ge-In,Se, Ge-Sb-Se 2 19 Se-P (red) GeS-GaSe 220 Cu-Se Pb-Sn-Se 221 Cr-Se GeSe,-In,Se, 222 Ref. 222 223 224 225 Other Compounds of Selenium.-A study of the crystal and molecular structures of bis(NN-diethyldiselenocarbamato)selenium(rI) has shown that, except for the terminal methyl groups, the molecules are planar, with non-crystallographic C2,(mm) symmetry, and they contain two types of Se-Se bond, of lengths 2.45 and 2.80 A.226 The preparation of salts of some iodoselenium(1v) cations has been described. Bis(perfluoroethy1) diselenide reacts quantitatively with [I2] [Sb2Fll] and [I,] [AsF,] to give corresponding salts of the [Se(C,F,)I,]' cation. Bis(perfluoroethy1) monoselenide reacts with [I2] [Sb,F,,], in the presence of excess of SbF5, probably yielding [Se(C,F,),I] [Sb2FlI]. The reaction of AsF, with elemental iodine and selenium in a 3 : 1 atomic ratio yields [SeI,] [ A sF ~] . ~~~ Bis(perfluoroethy1) di- selenide may be oxidized by both SbF, and [O,] [Sb2F11] to give orange or wine-red products, under appropriate conditions. These products have been formulated as the [Sb2Fl,]- salts of the novel cations [(Se(C,F,)},]' and [{Se(C,F,)},,]""', where n is thought to equal 1.228 4 Tellurium The Element.-The chemical transport of elemental tellurium in the presence of sulphur in a temperature gradient of 375--325°C has been shown, by a mass spectrometric study, to be due to the formation of the mixed molecules TeS, (x = 1-7) and Te2S, (y = 1-6).229 Ionizing radiation has been shown to increase the retention of the ground-state species from the isomeric transition of the tellurium isomers tellurium-121 m, -127rn, and -129m in telluric acid. The change in retention with length of irradiation resembles that taking place on heating.,,' The reaction of elemental tellurium with octaselenium bis(hexafluor0arsenate) in liquid SO, has been shown to yield the compound Te2se8(AsF6),,SO2. The Te,Sei' cation may be regarded as a bicyclic cluster formed by a six-membered ring fused with an eight-membered ring, with the two tellurium atoms in the three-co-ordinate positions (5 1). The compound Te3.7Se6.3(A~F6)2 has been pre- pared by the reaction of a 1: 1 Se-Te alloy with AsF, in liquid SO2. It is composed of discrete AsF, ions and of Te,.,Se;> ions, with some positional and occupational disorder. The cation is a bicyclic cluster, of structure (52), similar to that of Te2Seg+.231 226 R. 0. Gould, C. L. Jones, W. J. Savage, and T. A. Stephenson, J.C.S. Dalton, 1976, 908. 227 J. Passmore and P. Taylor, J.C.S. Dalton, 1976, 804. 228 J. Passmore, E. K. Richardson, and P. Taylor, J.C.S. Dalron, 1976, 1006. 230 S . Bulbulian and A. G. Maddock, J.C.S. Dalton, 1976, 1715. 231 P. Boldrini, I. D. Brown,, R. J. Gillespie, P. R. Ireland, W. Luk, D. R. Slim, and J. E. Vekris, Inorg. M. Binnewies, 2. anorg. Chem., 1976, 422, 43. 229 Chem., 1976, 15, 765. 264 Inorganic Chemistry of the Main-Group Elements Se I Se-Se, I Te' Te Se- Se ( 5 1) Se /Se-se \ \ / / Se - Se \ (52) Tellurium-Halogen Compounds.-Crystals of Te,Cl,, Te,Br, TeJ, p -TeI, and a-TeI have been prepared and used for structure determination. Te,Cl, has a monoclinic structure consisting of macromolecular units of tellurium atoms, which bears a close relationship to the structure of elemental tellurium. The structure of Te,X compounds consists of infinite double chains condensed to ribbons of Te, rings with boat conformation and with bridging halogen atoms at the edges. The P-TeI structure consists of endless chains of tellurium atoms, along which the iodine atoms occupy alternating bridging and terminal positions. The macro- molecular building principle of the subhalides of tellurium is degenerated in a-TeI to a Te, ring (the Te,I, molecule). The relationship of all these structures is clearly shown in Figure A study of the "'Te Mossbauer spectra at 4.2 K for the crystalline tellurium subhalides Te3Cl,, Te,X (X = Br or I), Te2Br0.7510.25, p-TeI, and a-TeI has shown the presence of at least two different tellurium sites in each subhalide, in accordance with the previous determinations of crystal The solvated entities Tei+, Te:+, and Teg' have been identified in reaction mixtures of dilute solutions of TeCl, and elemental tellurium in the low-melting NaC1-A1C13(37 : 63 mol%) solvent at 250 0C,234 The enthalpy of formation of the complex ion TeCl2- has been determined as AH?= -1020.4 kJ mol-l, and the affinity of gaseous TeC1, for chloride ion to be -304.1 kJ m01-l.~~' The i.r. and Raman spectra of TeClF, have been recorded, and assignments made on the basis of C,, symmetry. A normal-co-ordinate analysis was carried out on SClF5, SeClF,, TeClF,, SF6, SeF,, and TeF,, and the derived force constants were The sublimation and the decomposition of TeI, have been investigated. For the sublimation and the decomposition reactions (39) and (40), the values of enthalpy and entropy were derived. The existence of TeI, in the gaseous phase was demonstrated by equilibrium measurements and chemical transport experi- ment ~? ~~ The crystal structure of TeI, has been determined. The structure is built up of tetrameric (TeI,), molecules, which are not isomorphous with the (TeCl,), 232 R. Kniep, D. Mootz, and A. Rabenau, Z. anorg. Chem., 1976, 422, 17. 233 M. Takeda and N. N. Greenwood, J.C.S. Dalton, 1976, 631. 235 H. B. D. Jenkins and B. T. Smith, J.C.S. Faraday I, 1976, 72, 353. R. Fehrmann, N. J. Bjerrum, and H. A. Andreasen, Inorg. Chem., 1976, 15, 2187. W. F. V. Brooks, M. Eshaque, C. Lau, and J. Passmore, Canad. J. Chem., 1976, 54, 817. H. Oppermann, G. Stover, and E. Wolf, 2. anorg. Chem., 1976, 419, 200. 234 236 237 T e C t 2 . 8 3 5 1 0 3 . 2 T e 3 C l z b T e , X f 3 - T e I b d - T e I C F i g u r e 6 T h e s t r u c t u r e s o f s o m e t e l l u r i u m s u b h a l i d e s ( R e p r o d u c e d b y p e r m i s s i o n f r o m 2 . a n o r g . C h e m . , 1 9 7 6 , 4 2 2 , 1 7 ) 266 Inorganic Chemistry of the Main-Group Elements molecular structure, but which form a novel binary X4Y16 structure type, com- posed of edge-sharing TeI, octahedra (53). Mean Te-I bond lengths are 2.769, 3.108, and 3.232& for bonds to terminal, doubly, and triply bridging iodine atoms, respectively. Intermolecular I - I distances are short (3.870, 3.893, and I I I I (53) 3.932 A), indicating that there are weak bonding interactions between the Te4116 molecules. Within the series of the TeF,, TeCl,, and TeI, crystal structures, a major decrease in the stereochemical activity of the non-bonding electron pair on the Te'" ion was ob~erved. ~~* * * ~~ In an earlier study of the nuclear quadrupole resonance spectra of TeI, single crystals, a spectrum containing ten resonance lines was found, from which it was concluded that each tellurium atom has three terminal and two bridging iodine The conproportionation of diary1 ditellurides and aryltellurium trihalides, re- sulting in the formation of aryltellurenyl halides, has been investigated. The aryltellurenyl halides are, in general, unstable, and they disproportionate to diaryltellurium dihalides and elemental tellurium.241 In agreement with earlier work, tellurium tetrafluoride oxide dimer has been found to be strongly oxygen-bridged, in sharp contrast to tungsten tetrafluoride oxide, which is weakly fluorine-bridged in the solid state but which readily dissociates to a square-pyramidal monomer. Despite variable-temperature i.r. and Raman studies, no trace of reversible equilibria involving a terminal Te-0 bond was detected.?2 Trioxotetrafluoroditelluric(1v) acid, H2Te203F,, has been synthesized in HF solution. Its structure is characterized by Te203F4 groups linked by hydrogen bonds to form a very distorted diamond The compound U(OTeF& has been prepared in a pure state and found to be volatile, in spite of a molecular weight of 1669 mass units. It is thought that this is the inorganic non-polymeric molecule with the highest molecular weight known.244 238 V. Paulat and B. Krebs, Angew. Chern. Infernat. Edn., 1976, 15, 39. '" B. Krebs and V. Paulat, Acta Cr yst ., 1976, B32, 1470. 240 T. Okuda, K. Yamada, Y. Furukawa, and H. Negita, Bull. Chem. Soc. Japan., 1975, 48, 3480. 241 W. L. Dorn, A. Knochel, P. Schulz, and G. Klar, Z. Naturforsch., 1976, 31b, 1U43. I. Beattie, R. Crocombe, A. German, P. Jones, C. Marsden, G. van Schalkwyk, and A. Bukovszky, J.C.S. Dalton, 1976, 1380. K. Seppelt, Chem. Ber., 1976, 109, 1046. 242 243 J. C. Jumas, M. Maurin, and E. Philippot, J. Fluorine Chem., 1976, 8, 329. Elements of Group VI 267 Several studies of phase relationships or thermal behaviour of tellurium halides have been published. These are collected in Table 5.245--253 Table 5 Phase-diagram studies involving tellurium halides System Ref. Te0,-TeC1,-TeBr, 245 TeO,-TeCl,-TeI, 245 SiC1,-TeCl, 246 InBr,-TeBr, 247 Cs,TeBr6-K,TeBr6-Rb,TeBr6 248 B iCl,-Cu Cl-Te C1, 249 CuCl-FeCI,-TeCl, 249 BiCl,-GeCl,-TeCI, 250 Cs2TeBr6-K,TeBr6-T1,TeBr6 25 1 TeC1,-MCl, (M = Al, Ga, Fe, Nb, or Ta) 252 Te0,-TeX, (X =C1, Br, or I) 253 Tellurium-Oxygen Compounds.-The crystal structure of Te(OH),,NaF has been determined. Al(OH),-like layers of [NaTeO(OH)6]+are connected by OH * - - 0 hydrogen bonds (0 - * * 0 = 2.76 A) and the remainder of the OH groups are involved in short OH * - - F bonds. The fourth neighbour of the fluoride ion is Na’, thus increasing the co-ordination number of the sodium atom to seven. The octahedra are only slightly distorted, with Te-0 = 1.92 A. 1.r. and Raman spectra were also In the similar adduct Te(OH),,2KF the Te-0 bond length in the slightly distorted Te(OH)6 octahedra is 1.905A, with K’ in ten-fold co-ordination and all the OH groups being involved in short 0-H * The reactions of the chlorides of Al, Ga, and In with telluric acid have been studied at various values of pH in the MC13-H6Te06-KOH-H20 ~ystem.”~ The crystal structure of MgTe,O, has been found to contain Te,O, groups in which TerV is surrounded by three oxygen atom in a pyramidal arrangement, and one oxygen atom is common to both tellurium atoms. The Te205 groups are linked together into chains by longer Te-0 bonds. MnTe,OS crystallizes in the same structure, in which the manganese atom is octahedrally ~o-ordinated.’~’ The crystal structure of CrzTe4011 has been shown to contain (Cr2010)14- ions formed by two octahedra sharing an edge, and these units are connected to TeIV F hydrogen bonds of about 2.58 24s V. V. Safonov, V. S. Nikulenko, and B. G. Korshunov, Russ. J. Inorg. Chem., 1975, 20, 640. 246 A. V. Konov and V. V. Safonov, Russ. J. Inorg. Chem., 1975, 20, 1274. A. G. Dudareva, Yu. E. Bogatov, E. V. Galenko, A. K. Molodkin, and V. Ya. Lityagov, RWS. J. Inorg. Chem., 1975, 20, 1586. V. V. Safonov, T. V. Kuzina, and E. S. Malysheva, Russ. J. Inorg. Chem., 1975, 20, 1877. E. G. Kozachenko, V. V. Safonov, N. A. Levina, and V. I. Ksenzenko, Russ. J. h o g . Chem., 1976, 21, 118. 2so V. V. Safonov, Zh. K. Fes’kova, N. M. Grigor’eva, and V. I. Ksenzenko, Rwss. J. Inorg. Chern., 1976, 21, 318. V. V. Safonov, T. V. Kuzina, L. G. Titov, and B. G. Korshunov, Russ. J. Inorg. Chem., 1976, 21, 317. 247 248 249 25 1 252 A. V. Konov, S. M. Chemykh, and V. V. Safonov, Russ. J. Inorg. Chem., 1975, 20, 1736. 253 V. V. Safonov, V. S. Nikulenko, M. B. Varforoneev, V. A. Grinko, and V. I. Ksenzenko, Huss. J. 2s4 R. Allmann, Acfa Cryst., 1976, B32, 1025. 255 R. Allmann and W. Haase, Inorg. Chem., 1976, 15, 804. 2s6 N. K. Bol’shakova and A. A. Kudinova, Russ. J. Inorg. Chem., 1975, 20, 675. 257 M. Trornel, 2. anorg. Chem., 1975, 418, 141. Inorg. Chem., 1975, 20, 1370. 268 Inorganic Chemistry of the Main - Group Elements atoms and (Te20),+groups; Al,Te,O,, is isostructural with the chromium com- pound, and these results correct the compositions previously given for two phases reported to exist in the A120,-Te0, and Cr203-Te02 1.r. and Raman spectra of the hexagonal perovskites Ba2h4Te06, where M = Ni, Co, or Zn, have been investigated. The spectra are fairly complex, in accordance with the low symmetry of the molecules and the occurrence of a very different linking mode between the TeO, and MO, octahedra as compared with the cubic pero~ski tes.~~~ An ammonium tellurate with the empirical composition (NH4),0,2Te0,,3H20 has been prepared by precipitation from solution, and its thermal stability in the temperature range 25-740 "C studied. The sequence observed for the decompos- ition of the compound is shown in Scheme 2.',O (NH4),0Te0,,3H20 a (NH4),0,2Te0, 2TeO3,H@ / /413"C d 2Te02 440--545"c 2Te0, Scheme 2 A thermochemical study of tungstotelluric heteropolyacids of different composi- tions has been carried out.261 The A1Cl,-&H2Te06-H,0 system has been studied.262 The polymerization of the anions of tellurous and orthotelluric acids in solutions of various acidities has bekn investigated, using potentiometric titra- ti on^.^^^ A study of the crystal structure of Te20,S04 has shown the TerV co-ordination to be three-fold pyramidal, with Te-0 distances of 1.89, 1.91, and 2.00A. In addition, there are three longer Te-0 bonds of 2.26, 2.63, and 2.84A. The Te03 and sulphate units are connected to form sheets with S O distances between 1.47 and 1.49 A. Figure 7 shows the co-ordination around the Te'" i 0ns.2~~ Tellurides.-The unit cell of InTe has been shown to contain two distinct In atom sites. The first has In in tetrahedral co-ordination by four tellurium atoms, with a Te-In distance of 2.819 A. The second indium atom is surrounded in a cage-like system with eight tellurium atoms in a distorted antiprismatic arrangement, with Te-In distances of 3.576k The shortest Te-Te distance in the compound is 3.926 A.265 Indium polytelluride, In2Te,, is composed of two sheets of atoms constructed of chains of four-membered In-Te rings; each In is tetrahedrally co-ordinated, indicating that it may be thought of as being sp3-hybridized, with an average In-Te bond of 2.832 A, alternating with, and cross-linked by, groups of 258 G. Meunier, B. Frit, and J. Galy, Acra Crysr., 1976, B32, 175. 259 M. Liegeois-Duyckaerts, Spectrochim. Acta, 1975, 314, 1585. V. S. Gusel'nikov, V. M. Zaitsev, V. Ya. Mishin, and E. M. Rubtsov, Russ. J. Inorg. Chem., 1976,21, 454. E. Sh. Ganelina, L. B. Bubnova, and V. A. Borgoyakov, Russ. J. Inorg. Chem., 1975, 20, 1341. 260 26 1 262 P. K. Bol'shakova and A. A. Kudinova, Russ. J. lnorg. Chem., 1975, 20, 960. 263 E. Sh. Ganelina and V. P. Kuzmicheva, Russ. J. Inorg. Chem., 1975, 20, 1811. 264 G. B. Johansson and 0. Lindqvist, Acra Crysr., 1976, B32, 2720. 265 J. H. C. Hogg and H. H. Sutherland, Acra Cryst., 1976, B32, 2689. Elements of Group VI 269 Figure 7 The oxygen co-ordination of teZluriurn(Iv) in Te,O,SO, (Reproduced by permission from Acta Cryst., 1976, B32, 2720) three Te atoms which, on an ionic description, are (Te3),- polyanions. The average Te-Te bond in this anion is 2.837w.266 y-Ag8GeTe6 crystallizes in the cubic system, with a structure consisting of a rigid body of Te atoms consolidated by GeTe, tetrahedra, the silver atoms being disordered amongst the other tetrahedra formed by the tellurium atoms.267 The X-ray powder patterns of the tellurides CmTe,, CmTe,, Cm2Te3, and Cm,O,Te have been described.268 Two new systems of compounds formed be- tween rare earths, sulphur, and tellurium have been dernon~trated.~~’ Several phase systems involving tellurides have been described; these are collected in Table 6.270-276 Table 6 Phase-diagram studies involving tellurides Bi,Te,-GaTe 270 As-1-Te B i-Ga-Te 27 1 TlInTe,-InGaTe, As-Ge-Te 272 As,Te,-TlTe Ag,Te-T1,Te 273 As,Te,-Tl,Te System Ref. System Ref. 274 275 276 276 266 H. H. Sutherland, J. H. C. Hogg, and P. D. Walton, Acra Cryst., 1976, B32, 2539. 267 N. Rysanek, P. Laruelle, and A. Katty, Acta Cryst., 1976, B32, 692. 268 D. Darnien, A. Wojakowski, and W. Muller, Inorg. Nuclear Chem. Letters, 1976, 12, 441. 269 G. Ghemard, BulI. SOC. chim. France, 1976, 1007. P. G. Rustamov, N. A. Seidova, and M. G. Shakhbakov, Russ. J. Inorg. Chem., 1976, 21, 469. 271 P. G. Rustarnov, N. A. Seidova, and M. G. Shakhbakov, Russ. J. Inorg. Chem., 1976, 21, 412. 272 G. Z. Vinogradova, S. A. Dembovskii, and N. P. Luzhnaya, Russ. J. Inorg. Chem., 1975, 20, 769. 273 I. S. Kovaleva, V. A. Levshin, A. A. Tsurikov, and L. T. Antonova, Russ. J. Inorg. Chem., 1975, 20, 274 A. P. Chernov, S. A. Dembovskii, and N. P. Luzhnaya, Russ. J. Inorg. Chem., 1975, 20, 1208. 275 E. M. Godzhanov, Sh. M. Guseinova, F. M. Novruzova, M. M. Dadashev, and B. B. Guseinova, 276 G. M. Orlova, V. R. Panus, I. I. Kozhina, and I. A. Yanchevskaya, Russ. J. Inorg. Chem., 1975,20, 270 1091. Russ. J. Inorg. Chem., 1975, 20, 1704. 1687. 270 Inorganic Chemistry of the Main - Group Elements Other Compounds containing Tellurium.-Variable-temperature n.m.r. studies of the complexes MX,(ZEt,),, where Z = S, Se, or Te; M = Pd or Pt; and X = C1, Br, or I, have indicated that an inversion of configuration at the pyramidal chalcogen atom is a ready process. The barriers to inversion are in the order Te > Se > S, and are sensitive to the trans influence of the opposite ligand.277 New complexes of copper(1) salts with diary1 ditellurides and dialkyl ditellurides, together with derivatives of tellurols CuTeR (R = alkyl or aryl), have been de~cribed.~” Tetraethylammonium tellurocyanate has been prepared and the electrochemical oxidation of the TeCN- anion in acetonitrile studied. The reaction takes place with the transitory formation of the [(TeCN),]- complex ion, which then gives the unstable (TeCN), dimer; this in turn decomposes into tellurium and ~yanogen.’ ~~ Extending the earlier preparation and spectral study of several tetra- halogenoaryltellurates(1v) Y’ ArTeX,, the ammonium, sulphonium, selenonium, arsonium, and iodonium derivatives have been prepared, thus giving more complete spectral data.280 The following new compounds containing perfluoroalkyl-tellurium linkages have been synthesized: MeTeCF,, (CF,),Te, MeTeC2F5, and (C2FS),Te. The compounds were prepared by the photochemical interaction of Me,Te and the appropriate perfluoroalkyl iodide.281 277 R. J. Cross, T. H. Green, and R. Keat, J.C.S. Dalton, 1976, 1150. 278 I. Davies and W. R. McWhinnie, Znorg. Nuclear Chem. Letters, 1976, 12, 763. 279 G. Cauquis and G. Pierre, Bull. SOC. chim. France, 1976, 736. 280 N. Petragnini, J. V. Comasseto, and Y. Kawano, J. Znorg. Nuclear Chem., 1976, 38, 608. 281 M. L. Denniston and D. R. Martin, J. Znorg. Nuclear Chem., 1975, 37, 1871. 7 The Halogens and Hydrogen BY M. F. A. DOVE 1 Halogens The Elements.-The inorganic chemistry of fluorine has been reviewed for the period 1966-69 by Russian authors,’ and Kuhn has produced a concise account of the electrochemistry of this element.2 Fluorine- 18 tracer reactions have been reviewed by Rowland and co-w~rkers,~ with particular emphasis on the labelling of organic compounds. The excitation curve for 18F production by deuteron bombardment of Ne has been meas~red: ~ production of up to 20 mCi PA-’ h-’ has been achieved by the use of a remote-controlled neon target.’ J ones and Skolnik6 have reviewed reactions of fluorine atoms, with emphasis on the determination of rates and mechanisms; this review does not include work on fluorine-containing chemical lasers. The kinetics of gas-phase reactions of fluorine, both atomic and molecular, have been reviewed in depth by Foon and Kauf man .7 A technique has been described for the atomic resonance detection of ground- state fluorine 2p’ ‘PJ atoms in a flow system.8 E.s.r. detection methods have been applied to reactions of F, F2, and CF3H.9 Reactions of F atoms with a range of materials ( e. g. alumina, quartz, nickel, stainless steel) have been investigated over the temperature range 300-560 K.l0 The rate constant of the fast reaction of F atoms with HC1 has been measured in a flow system, using mass spectrometric analysis.” Absolute rate constants for the reaction of F atoms with NO in the presence of some third bodies have been reported;” the temperature dependence 1 2 3 4 5 6 7 8 9 10 11 12 A. Yu. Shagalov and T. I. Belyakov, ‘Preparation Methods, Properties and Use of Fluorine and its Inorganic Compounds’, Bibliographic index of Soviet and foreign literature, No. 1, Part 2, Gos. Inst. Prikl. Khim., Leningrad, U.S.S.R., 1975. A. T. Kuhn, ‘Encyclopaedia of the Electrochemistry of the Elements’, ed. A. J . Bard, Dekker, New York, 1975, Vol. 4, pp. 43-86. F. S. Rowland, J. A. Cramer, R. S. Iyer, R. Milstein, and R. L. Williams, Nippon Aisotopu Kuigi Hobunshy 1973, 360. T. Nozaki, T. Karasawa, M. Okanu, A. Shimamura, M. Iwamoto, T. Ido, and Y. Makide, IPCR Cyclotron Rogress Reports, 1972, 127. M. Guillaume, Nuclear Insfrum. Methods, 1976, 136, 185. W. E. J ones and E. G. Skolnik, Chem. Rev., 1976, 76,563. R. Foon and M. Kaufman, Progr. Reaction Kinetics, 1975, 8, 81. P. P. Bemand and M. A. A. Clyne, J.C.S. Faraday II, 1976,72, 191. I. B. Goldberg and G. R. Schneider, J. Chem. Phys., 1976, 65, 147. P. C. Nordine and J. D. Legrange, Amer. Inst. Aeronautics Astronautics J., 1976,14,644. H. G. Wagner, J. Warnatz, and C. Zetzsch, Ber. Bunsengesellschaft phys. Chem., 1976, 80, 571. E. G. Skolnik, S. W. Veysey, M. G:Ahmed, and W. E. J ones, Cunad. J. Chem., 1975, 53, 3188. 27 1 272 Inorganic Chemistry of the Main-Group Elements (168-359 K) of the bimolecular rate constant for NO+ F2+ FNO + F has been investigated by Kolb.13 Interferometric measurements of i.r. emissions from vibrationally excited HF molecules have yielded evidence for reaction ( l).14 Crossed molecular beam techniques were used to study the reaction between F, and above a threshold F, + (HI), + HF + HI +I + F (1) energy of 4 kcal mol-1 the observed products are 12F and F, whereas at even higher energies I F is also formed. Russian workers have reported the kinetics and mechanism of the fluorination of CO to carbonyl fluoride.', The electronic spectrum of F,, in absorption and in emission, has been photographed with sufficient resolution to warrant rotational analysis of many bands;17 the dissociation energy, Do(F,), was estimated to be 12 920 f 50 cm-'. New measurements of the pure rotational Raman spectrum of F2 have been reported by Long et a1.,18 who have calculated more precise values of the rotational constants Bo and Do and of the bond lengths r, and re. Asprey" has described how 98% pure F,, at low pressure, can be converted into a sample of F2 of 99.7% purity at high pressure (ca. 25 atm). Impure Fz is used to fluorinate KF and NiF, (molar ratio 3: 1) to form a mixture of composi- tion K,NiF,: the latter exerts a fluorine pressure of 25 atm at 400 "C and decomposes to K3NiF6. This nickel(II1) complex can be re-fluorinated to K3NiF,, and Asprey reports that the system shows no loss in efficiency after more than twenty cycles. The possibility of using solid reactants for the preparation of 'fluorine equivalent' gas (i.e. F, F,, or NF,) has been studied.,' A short-list of three reagents (KBrF,, KCIF,, and LiMnF,) was drawn up after considering criteria such as toxicity, cost, safety, and vapour pressure. Perov and Nikolaev,' have reviewed advances in fluorine calorimetry; French workers have described several bomb calorimeters suitable for use with F2 or with other fluorinating agents.', By way of contrast, Lagow et uL2, have applied their techniques of direct fluorination to N-containing organic compounds, and they were able to report the synthesis, in modest yield, of the corresponding N- containing fluorocarbon. Ground-based i.r. solar spectroscopy, with 0.06 cm-l resolution, may be used to monitor species such as CFCl,, CF2C12, and HN03 in the atmo~phere.'~ Higher resolution or a site at high altitude were shown to be essential for the monitoring l3 C. E. Kolb, J. Chem. Phys., 1976, 64, 3087. l4 J. F. Durand and J. D. McDonald, J. Amer. Chem. Soc., 1976, 98, 1289. l5 M. J. Coggiola, J. J. Valentini, and Y. T. Lee, Internat. J. Chem. Kinetics, 1976, 8, 605. l6 G. A. Kapralova, S. N. Buben, and A. M. Chaikin, Kinetics and Catalysis, 1975, 16, 508. '' E. A. Colbourn, M. Dagenais, A. E. Douglas, and J. W. Raymonda, Canad. J. Phys., 1976,54,1343. H. G. M. Edwards, E. A. M. Good, and D. A. Long, J.C.S. Faraday 11, 1976,72,984. L. B. Asprey, J. Fluorine Chem., 1976, 7, 359. 2o C. E. Fogle and J. D. Breazeale, U.S. NTIS, A D Report, 1976, AD-A022099 (Chem. Abs., 1976,85, 21 V. S. Pervov and N. S. Nikolaev, Russ. Chem. Rev., 1976, 45, 318. 22 P. Barbieri, J. Carre, and P. Rigny, J. Fluorine Chem., 1976, 7, 511. 23 J. L. Adcock, B. D. Catsikis, J. W. Thompson, and R. J. Lagow, J. Fluorine Chem., 1976, 7, 197. 24 D. G. Murcray, F. S. Bonomo, J. N. Brooks, A. Goldman, F. H. Murcray, and W. J. Williams, Geophys. Res. Letters, 1975, 2, 109; C. M. Bradford, F. H. Murcray, J. W. Van Allen, J. N. Brooks, D. G. Murcray, and A. Goldman, ibid., 1976, 3, 387. 80 474). The Halogens and Hydrogen 273 of other species, such as NO, HCl, and even NO2. The presence of HF in the upper stratosphere has been inferred from an absorption band, at 4038.97 cm-', in the solar spectrum, as measured from a balloon at an altitude of 27.5 km.25 The reactions (2), with x = 1, 2, and 3, have been investigated by flash photolysis, using time-resolved absorption spectroscopy:26 it was suggested that O(2'D2) +CFxC1, + CFxC1,-, f C10(X21[) (2) such reactions may provide only a minor sink for CF2C12 and CFCl, relative to photodissociation. The first absolute rates of collision quenching of atomic oxygen with these chlorofluoromethanes (x = 1 and 2) have been rep~rted.~' Photo- decomposition of these halogenomethanes has been investigated, using CH, and GH, as interceptors of C1 atoms?8 The results indicate that the dominant photochemical process is ejection of C1atoms, with a quantum yield approaching As the photon energy is increased there is a rapidly increasing probabil- ity that photon absorption will lead to the release of two C1atoms.28 Pure rotational Raman spectra have been measured for 79Br2 and 81Br2; rotational constants Be and centrifugal distortion constants were calculated from the data.30 An electrochemical study of Br2 and I2 in anhydrous HF has revealed that several irreversible one-electron oxidation processes The gas-phase reaction of GFSI with HI in the temperature range 478-560 K has reaction (3) C2F51 +I + C2F5 +I2 (3) as its rate-determining from the kinetic data, the C-I bond dissociation energy was shown to be 52.5 kcalmol-'. The thermodynamic stability of the charge-transfer complexes of I2 with six polynuclear aromatic hydrocarbons has been studied by vapourization techniques and solid-state electrochemical cells:33 the results are summarized in Table 1. Halides.-Aspects of the chemistry of molten fluorides have been reviewed by Bamberger and T h~ma. ~~ Trinuclear cationic species generated in the vapours above the alkali-metal halides have been studied by mass spectrometry; these results, combined with those from ab initio quantum-mechanical calculations, indicate that the stability of M2Xf follows the sequence Li2F+> Na2F', Li2CI' > Na2Cl'.35 Gusarov has calculated the energies of four configurations of hi&+ (M=Li or Na), using an ionic His results suggest that the linear DDDh model is the most stable. " R. Zander, Compr. rend., 1975, 281, B, 213. '' H. M. Gillespie and R. J. Donovan, Chem. Phys. Letters, 1976, 37, 468. '' I. S. Fletcher and D. Husain, Chem. Phys. Letters, 1976, 39, 163. *' R. E. Rebbert and P. J. Ausloos, J. Photochem., 1975, 4, 419. 29 R. K. M. Jayanty, R. Simonaitis, and J. Heicklen, J. Photochem., 1975, 4, 381. 30 P. Baierl, J. G. Hochenbleicher, and W. Kiefer, Appl. Spectroscopy, 1975, 29, 356. J. Dugua, 0. Vittori, and M. Porthault, Bull. Soc. chim., France, 1976, 49. 32 E. C. Wu and A. S. Rodgers, J. Amer. Chem. Soc., 1976, 98, 6112. S. Aronson, G. Sinensky, Y. Langsam, and M. Binder, J. Inorg. Nuclear Chem., 1976, 38, 407. ( a) C. E. Bamberger, Ado. Molren Salt Chem., 1975, 3, 177; ( b) R. E. Thoma, ibid., p. 275. 31 33 35 C. E. Rechsteiner, R. P. Buck, and L. Pedersen, J. Chem. Phys., 1976, 65, 1659. 36 A. V. Gusarov, Russ. J. Phys. Chem., 1975, 49, 1576. T a b l e 1 D a t a f o r c h a r g e - t r a n s f e r c o m p l e x e s o f p o l y n u c l e a r a r o m a t i c h y d r o c a r b o n s w i t h i o d i n e H y d r o c a r b o n ( 1 2 ) P y r e n e ( P y ) P e n t a c e n e ( P n ) P e r y l e n e ( P e ) P e r y l e n e ( P e ) 1 , 1 2 - B e n z p e r y I e n e ( B P ) 1 , 1 2 - B e n z p e r y l e n e ( B P ) C o r o n e n e ( C n ) O v a l e n e ( O v ) - A @ ( 3 5 0 K ) / k c a l ( m o l . 1 2 ) - ' 2 . 8 4 3 . 4 3 . 4 4 . 9 4 . 7 3 . 9 4 . 1 4 . 4 4 . 5 3 . 9 3 . 8 3 - 9 3 . 8 5 . 2 5 . 2 5 . 3 5 . 1 P ( 3 5 0 K ) / T o r r 1 2 . 8 5 . 5 5 . 5 0 . 6 8 0 . 9 2 2 . 9 2 . 2 1 . 4 1 . 2 2 . 9 3 . 3 3 . 0 3 . 3 0 . 4 6 0 . 4 7 0 . 3 7 0 . 5 2 - A H ? k c a l ( m o l . 1 2 ) - ' 1 4 . 8 8 1 1 . 9 1 2 . 4 1 2 . 0 1 1 . 6 1 3 . 5 1 4 . 3 1 2 . 9 1 3 . 9 1 4 . 5 1 4 . 1 1 5 . 6 1 4 . 5 1 1 . 9 1 2 . 3 1 2 . 7 1 1 . 9 The Halogens and Hydrogen 275 A new type of intercalate has been reported: it was prepared by the reaction of Ag2F with benzonitrile at room temperat~re.~~ At least 2 mole of PhCN are taken up over a period of a few weeks. X-Ray diffraction studies of the intercalate showed that the c parameter had changed from 5.78 A (in Ag,F) to 23.4 A; the electrical conductivity of the crystals was reported to be lo3 n-' cm-'. Opalovskii et al.38 have studied the solubilities in the systems MeC0,H-MF- H20, where M = Li,38 Na,38 K,38 and Rb,39 at 25 "C. They obtained the following solvates: NaF,xMeCO,H (x=O.2 or 1.0); KF,yMeCO,H ( y = O. 5 , 1, or 2); RbF,zMeCO,H ( z = 0.5, 0.8, 1, 1.3, 2). Solutions of CsF in RC02H (R = H, Me, Et, or Pr) have been studied by 'H n.m.r. and i.r. ~pectro~copy:~~ two solvent- independent i.r. bands, at ca. 2120 and 1550 cm-', were said to be characteristic of strong iiydrogen-bonding between F- and the carboxylic acid. The reactions of KF in glacial acetic with chlorocarboxylic acids, amides, and chlorides have been investigated by Emsley and Clark:41 in general, the reaction products were found to be acetoxy-derivatives, as in reaction (4). The role of KF in promoting the Cl,CHCO,H +2KF,MeCO,H + (MeCO,),CHCO,H +2KC1 (4) alkylation of certain aromatic compounds R'YH (e. g. PhC02H, PhOH, PhSH, and PhNMeH) has been The reaction (5), where R2X is a halogeno- alkane, is thought to involve the formation of a hydrogen-bond between F- and HYR'. R'YH + 2KF + R2X + R'YR2 + KX + KHF, ( 5) Mass spectral intensities and sensitivities of a range of mainly inorganic fluorine compounds, including F2, ClF, ClF3, IF5, IF7, HF, and XeF4, have been measured and tabulated by Beattie.43 The chemistry of the formation of chloride-bridged species is the subject of a review by Schafer.44 X-Ray photoelectron spectroscopy of a number of inorganic chloro-complexes has shown that the 2 p binding energy is greater for bridging than for terminal chlorine moreover, this techni- que can be usefully applied to the characterization of complexes of the types [ML5Cl]C12, [ML4C12]Cl, erc., provided that L does not hydrogen-bond to C1-. The passage of chloride ion through a column of an anion-exchange resin leads to an enrichment of 37Cl in the first fractions and a depletion in the last fractions (Figure l).46 This behaviour can be accounted for if the lighter isotope has the larger ionic radius. The separation of, and detection-limits for, the halide ions on a thin layer of activated silica gel (bonded on aluminium foil) have been studied " V. M. Koshkin, E. B. Yagubskii, A. P. Mil'ner, and Yu. R. Zabradskii, Pis'ma Zhur. Eksp. Teor. Fiz., '' A. A. Opalovskii, N. I. Vivdenko, and V. N. Shevchenko, Russ. J. Inorg. Chem., 1976, 21, 1678. '' A. A. Opalovskii, N. I. Vivdenko, and V. F. Dement'eva, Russ. J. Inorg. Chem., 1976, 21, 1702. J. Emsley and 0. P. A. Hoyte, J.C.S. Dalton, 1976, 2219. 41 J. H. Clark and J. Emsley, J.C.S. Dalton, 1975, 2129. 42 J. H. Clark and J. M. Miller,J.C.S. Chem. Cornrn., 1976, 229. " W. H. Beattie, Appl. Spectroscopy, 1975, 29, 334. ec H. Schafer, Angew Chern. Internat. Edn., 1976, 15, 713. 45 J. R. Ebner, D. L. McFadden, D. R. Tyler, and R. A. Walton, Inorg. Chern., 1976, 15, 3014. 46 K. G. Heumann and R. Hoffmann, Angew Chem. Inremar. Edn., 1976, 15, 55. 1976, 24, 129. 276 Inorganic Chemistry of the Main- Group Elements 3.160 3.140 3.j 20 3.100 3,080 0 20 LO 60 ao 100 Amount of CI- eluted I%] - Figure 1 Isotope ratio 35C1/37C1 as a function of the amount of C1- eluted. Eluant i s 0.1 M-NaNO,. The horizontal line indicates the starting isotope ratio 35C1/37C1 = 3.130 (Reproduced by permission from Angew. Chem. Internat. Edn., 1976, 15, 55) by Thielemann.47 Radio-iodine labelling of aromatic compounds can be conven- iently accomplished in the temperature range 110-180 “C, using labelled NaI in molten a~etamide.~’ Interhalogens and Related Species.-Eachus and S ~mo ns ~~ have reported the detection of the novel Cld radical cation in mixtures of Cl, and SbF5 cooled to 77 K: the e.s.r. spectrum is consistent with the presence of four equivalent chlorine atoms, possibly in a planar arrangement. The trihalogen radicals IIF and ClIF and the pseudo-trihalogen radical HI F have been produced from the reac- tions of F, with 12, ICI, and HI in crossed molecular beams.” The photolysis, using light from a mercury arc and from an Ar+ laser, of samples of ClF and F2 in a solid N, matrix produces a species which has been characterized by i.r. (doublet 578, 570 cm-’), Raman (500 cm-l), and U.V. (320 nm) spectroscopy: these features were assigned to the ClF, free radical, for which the authors proposed a slightly bent ~tructure.~’ On the other hand, SCF theory, with a variety of basis sets, has been used to predict the structures of the radicals ClF, (Cl-F = 1.72 A and LFClF = 148”) and ClF4 (planar).52 The e.s.r. spectra of XF6 (X=Cl, Br, or I) in solid SF, at 27 and 110K have been re-examined; formally forbidden, or ‘n.m.r.’, transitions for BrF6 and IF6 have been detected, and these results have been used to calculate more precise e.s.r. 47 H. Thielemann, Z. Chem., 1976, 16, 283. 48 H. Elias and H. F. Lotterhos, Chem. Ber., 1976, 109, 1580. 49 R. S. Eachus and M. C. R. Symons, J.C.S. Dalton, 1976,431. ’O J. J. Valentini, M. J. Coggiola, and Y. T. Lee, J. Amer. Chem. Soc., 1976, 98, 853. ” E. S. Prochaska and L. Andrews, Inorg. Chem., 1977, 16, 339. ” S. R. Ungemach and H. F. Schaefer, J. Amer. Ge m. Soc., 1976, 98, 1658. The Halogens and Hydrogen 277 parameter^.^^An analysis of the spectra at 27 K clearly shows that the radicals possess 0, symmetry and that the unpaired electron occupies an antibonding al, orbital based on fluorine 2p,-orbitals and s-orbitals of the central atom. The molecular spectra of MF ( M=K, Rb, or Cs) and F2 that have been deposited simultaneously in an Ar matrix at 15 K contain bands at 550 (i.r.) and 461 cm-' (Raman) which Ault and Andrew$, have assigned to v3 and v1 of the unstable and previously unreported F; ion. Laser excitation of alkali metal- bromine samples in an Ar matrix produces M' Bri, the Raman spectra of which contain a band in the range 149-160cm-' that is assignable to the Br-Br stretching vibration of Andrew? has also obtained the optical spectra of X, (X = F, C1, Br, or I) and of Cl, in Ar matrices at 17 K. Chlorine monofluoride reacts with SCl, and SeCl, to form the corresponding tetrafl~orides,~~" whereas TeCl, is converted into TeC1F5.57b Selenium dioxide and oxyfluoride are also converted into SeF,; oxygen and FClO, appear among the The presence of the latter indicates that the reaction may proceed by the addition of ClF across a Se-0 bond to give ClzO, which is known to react with ClF to form Clz and FC102. Russian workers have reported a number of reactions of chlorine(1) fluoro~ulphate.~~ The fluorination of cyanogen chloride with KF under mild conditions yields (CF3),NCN, CF3NCF2, and cyanuric fluoride.59 Radio-chlorine does not exchange between C1, and ClF3 in the liquid phase at -80 "C or in the gas phase up to 165 "C;6' however, the exchange between C1, and ClF3 has a half-life of 1 h at 20°C. The reaction of Cl, with ClF3 to form ClF appears to be essentially homogeneous in the gas phase and proceeds at a conveniently measurable rate in the temperature range 180-250 "C: the activa- tion energy is 20.18 kcal mol-' for the second-order reaction. The exchange of chlorine between ClF3 and ClF was found to be homogeneous in the temperature range 203-245 "C. The intercalation compound C14F,ClF3,3HF apparently re- tains the ClF3 unit when the HF is displaced by other protonic acids, uiz. CF3COzH, CH3COZH, HC104, and HN03.6' D.t.a. of the ClF3-SbF, system has demonstrated the existence of four adducts, 3: 2, 1 : 1, 1 : 2, and 1 : 4.62 The first of these melts incongruently, but the remaining three adducts melt at 285, 11, and 25 "C, respectively. Nuclear quadrupole coupling constants, the dipole moment, and the structure of ClF, have been redetermined from new determinations of the microwave spectrum: they are in better agreement with one another than with the data " A. R. Boate, J. R. Morton, and K. F. Preston, Inorg. Chem., 1975,14, 3127; J. Phys. Chem., 1976, 54 B. S . Ault and L. Andrews, J. Amer. Chem. Soc., 1976, 98, 1591. " C. A. Wright, B. S. Auk, and L. Andrews, Inorg. Chem., 1976, 15, 2147. 56 L. Andrews, J. Amer. Chem. SOC., 1976, 98, 2147, 2152. " ( a ) C. Lau and J. Passmore, J. Fluorine Chem., 1975, 6, 77; ( b ) Inorg. Chem., 1974, 13, 2278. " A. V. Fokin, A. D. Nikolaeva, Yu. N. Studnev, A. I. Rapkin, N. A. Proshin, and L. D. Kuznetsova, " J. D. Cameron and B. W. Tattershall, Angew. Chem. Internat. Edn., 1975, 14, 166. 80, 2954. Izvest. Akad. Nauk S.S.S.R., Ser. khim., 1975, 1000. M. T. Rogers, J. C. Sternberg, and J. P. Phelps, J. Inorg. Nuclear Chem., Supplement, 1976, 149. A. S. Nazarov, N. F. Yudanov, and Yu. V. Chicagov, Russ. J. Inorg. Chem., 1976, 21, 1248. V. F. Sukhoverkhov and V. I. Shpanko, Russ. J. Inorg. Chem., 1976, 21, 603. Jurek, and J. Chanussot, J. phys. (Paris), 1976, 37, 495. 60 62 63 H. K. Bodenseh, W. Huettner, and P. Nowicki, Z. Naturforsch., 1976, 31% 1638: P. Goulet, R. 278 Inorganic Chemistry of the Main - Group Elements reported in 1974. Weulersse and co- w~rkers~~ have obtained information about phase transitions and molecular motions in the three solid phases of CIFS, over the temperature range 77-181K. On the other hand, the temperature depen- dence (4.2-135 K) of ,'Cl n.q.r. frequencies in ClF, shows no sign of the phase change II+III observed by 19F n.m.r. spectroscopy at 117 K.65 Apart from the known 1 : 1 adduct of ClF, and SbF,, two other adducts have been obtained for the first time in the course of a study of the system by d.t.a.66 These are the 1 : 2 and 1 : 4 adducts. Christe et al. have re-examined the vibrational spectra of SF4 and ClF4+SbF,;67 because of a change in the assignments for SF, they have revised the assignments and force-field values for the isoelectronic ClFi cation. Bromine(1) fluoride has been generated in an inert matrix by photo-elimination from SF,Br; the Br-F stretching motion occurs at 650.5 cm-', having a force constant of 3.83 mdyn The determination of the crystal structure of bis(quino1ine)bromine perchlorate has confirmed the expected ionic comp~si ti on:~~ bromine is linearly co-ordinated by N in the nearly coplanar cations. The difference between the Br-N distances (2.10 and 2.165A) is unexpected, particularly since the I' analogues with pyridine and thiourea as donor are exactly symmetrical. The i.r. spectra of XS0,F (X=Br, Br,, I, C102, HO, and DO) have been obtained at 80K, and detailed vibrational assignments have been given.70 Some interesting reactions [(6), (7), and (S)] of bromine(1) fluorosulphate have been reported by Aubke and co-workers, in which bromine(i~~)-containing cations are produ~ed. ~'>~~ CI (6) SbFS BrS0,F +Br, - [Br;][Sb,FJ 4 [Br,C1+][Sb,F;6] SbFS BrS0,F +C1, - [BrCl,+][SbF;],3.46SbFs (7) 2BrSO3F,Sn(SO,F), [Br(SO,F),+],[Sn(SO,F):-] (8) The dielectric constant of BrF, has been shown to be 107 at 25°C;73 the electrical conductivity of the sample used was 8 X lop3 Ln-' cm-'. Sukhoverkhov et aL74 have investigated the BrF,-CsF-HF system at 20°C. Three complexes are formed in the system under these conditions, namely CsF,3HF and CsF,nBrF, ( n = 1 and 2); the solvates were characterized by their elemental analyses and by i.r. spectroscopy. The crystal structure of (BrF,),GeF6 is quite consistent with the 64 J. M. Weulersse, P. Rigny, and J. Virlet, J, Chem. Phys., 1975, 63, 5190. J. M. Weulersse, J. Virlet, and L. Guibe, J. Chem. Phys., 1975, 63, 5201. V. F. Sukhoverkhov and V. I. Shpanko, Russ. J. Inorg. Chem., 1975, 20, 1706. K. 0. Christe, E. C. Curtis, C. J. Schack, S. J. Cyvin, J. Brunvoll, and W. Sawodny, Specfrochim. Acra, 1976, 32A, 1141. 65 66 67 68 R. R. Smardzewski and W. B. Fox, J. Fluorine Chem., 1976, 7, 453. 69 N. W. Alcock and G. B. Robertson, J.C.S. Dalton, 1975,2483. 70 W. W. Wilson, J. M. Winfield, and F. Aubke, J. Fluorine Chem., 1976, 7, 245. 71 W. W. Wilson, B. Landa, and F. Aubke, Inorg. Nuclear Chem. Letters, 1975, 11, 529. 72 P. A. Yeats, B. Landa, J. R. Sams, and F. Aubke, Inorg. Chem., 1976, 15, 1452. 73 D. Martin and G. Tantot, J. Fluorine Chem., 1975, 6, 477. 74 V. F. Sukhoverkhov, N. D. Takanova, and A. A. Uskova, Russ. J. Inorg. Chem., 1976, 21, 1234. The Halogens and Hydrogen 279 ionic f orm~l ati on.~~ There are two fluorine atoms close to Br (mean distance 1.71 A) whereas the next-nearest fluorines are at 2.21 A. The co-ordination around Ge is pseudo-octahedral, with two short and four long Ge-F bonds. The composition of the BrF,-HF azeotrope has been determined by E ~h o v ~~ as a function of temperature in the range 18--67°C. Quinuclidinium pentaiodide is best described by the formula [C7H13NH+]I,,12;77 Figure 2 shows a section of the structure that has been determined by X-ray crystallography. Although the 1-1 distance in the I2 units is only marginally longer than that in free I2 (2.715&, the 12-1i contacts are significantly less than the sum of the van der Waals’ radii. The reaction of iodine with silver nitrate, or perchlorate, and quinuclidine in the molar ratio 1:1:2 produces the bis(quinuc1idine)iodonium cation, which is the most stable iodonium cation of this type so far isolated.78 The same workers have investigated the vibrational spectra of this, as well as that of the bis(urotropine)iodonium cation. Their results are consistent with a centrosymmetric N-I-N arrangement. Iodine(I), generated anodically from I, at a platinum electrode in MeCN or CH2C12, has been used to iodinate substituted benzenes, e.g. ethyl benz~ate.~’ Some interesting inorganic iodination reactions have been reported by Passmore and co-workers.80,81 Excess sulphur reacts with [Ii][AsF,] or [Ii][Sb,Fyl] to form the novel cation S71+.80 The same iodinating agents convert (C2F,Se), and (C,F,),Se into (C2F5)SeIl and (C2F=J2SeI+, respectively.81 N-Iododimethylamine and N13,3NH3 can be used as iodinating agents for organic substances; however, reactions of the former require that there be greater electrophilic character in the organic reagent.82 n I0101 I T I Figare 2 Projection on the l OT plane of the structure of [C7H13NH+]I;,12 (Reproduced by permission from Z. Naturforsch., 1975, 30b, 720; in this Figure, iodine is denoted by J) 75 A. J. Edwards and K. 0. Christe, J.C.S. Dalton, 1976, 175. 77 J. Jander, H. Pritzkow, and K.-W. Trommsdorff, Z. Naturforsch., 1975, 30b, 720. 79 L. L. Miller and B. F. Watkins, J. Amer. Chem. SOC., 1976, 98, 1515. V. K. Ezhov, Rum. J. Inorg. Chem., 1976, 21, 1154. J. Jander and A. Maurer, Z. anorg. Chem., 1975, 416, 251. J. Passmore, P. Taylor, T. K. Whidden, and P. White, J.C.S. Chem. Comrn., 1976, 689. J. Passmore and P. Taylor, J.C.S. Dalton, 1976, 804. 82 G. Geursen, J. Jander, K. Knuth, and R. Michelbrink, 2. anorg. Chem., 1975, 414, 10. 76 78 60 81 280 Inorganic Chemistry of the Main - Group Elements The kinetics of the formation of ICN in aqueous solution [reaction (9)] have been i n~esti gated:~~ in the presence of excess HCN, all of the I; is converted into ICN. 1; + HCN- 21- + ICN + H' ( 9) Solutions of IN3 are relatively stable in CH2C12, CCl,, or C6H6i8, vibrational spectra have been obtained of IN3 in these solvents and also of the pure solid. Iodine azide reacts with B13 to produce I2 and the new compound B12(N3). F n.m.r. spectroscopy indicates that, at -40 "C, IF3 is in equilibrium with IF, and I F in MeCN solution.85 Between -40 and +30"C an exothermic reaction occurs which has been attributed to the decomposition of IF. The direct fluorina- tion of perfluoroalkyl iodides RJ has now been extended to include Rf = C2F5 and n-C3F7.86 The reactions were carried out in MeCN at -78 "C to produce insoluble RJF, in high yield: at about -40°C further fluorination occurs, to form soluble RfIF4. Trifluoromethyliodine(n1) nitrate can be prepared by the reaction of either CF31F2 or CF310 with N205, as well as from CF31 and C1N03:87a when either CF31F2 or CF31 was used as the starting material, an intermediate product, CF31X(N03) (X = F or Cl), could be detected. Trifluoromethyliodine(II1) nitrate decomposes in vucuo above -20 "C as reported The thermal decomposition of iodine(m) trifluoroacetate begins above 105 "C, according to equation This compound reacts with alkanes and ethers over 19 81(CF,C02), + 8(CF3CO),0 i- 4C2F6 +8CO +41204( 1, +1205) (10) a period of 3 days to give trifluoroacetate derivatives?' these reactions are slower than the analogous reactions of I(CF,SO,),. The novel iodine(II1) fluorosulphate cation has been synthesized [reaction (ll)] by Aubke et According to Bali 21(S03F), +Sn(SO,F), + [I(SO,F)~],[Sn(SO,F)~-] and Mal h~tra,'~ solutions of IPO, and I(MeCO,), form I(HSO,),' in disulphuric acid; other cations of the type IX,' and 12X+were produced in solution by the oxidation of iodine compounds by X2 (X=C1 or Br). Schmeisser et aL9' have investigated the compounds IX,IF5,2py (X = F, C1, or Br) by vibrational spectros- copy. The Cl n.q.r. spectrum of IClT, in CsICl,, has been reported and assigned:92 the charge distribution was calculated, being +1.25 on I and -0.55 on C1. Iodine(v) fluoride exchanges fluorine with I8F-labelled alkylfluorosilanes more slowly than does IF4(OMe).93 Thermal decomposition of IF5,SbF, takes place with the loss of IF5 and the formation of the 1 : 2 addu~t.'~ The structure of this new 83 J. 0. Edwards, M. Kaus, and M. C. Sauer, Inorg. Chem., 1976, 15, 1723. 84 K. Dehnicke, Angew. Chem. Internat. Edn., 1976, 15, 553. E. Lehmann, D. Naumann, and M. Schmeisser, J. Fluorine Chem., 1976, 7, 33. D. Naumann, M. Schmeisser, and L. Deneken, J. Inorg. Nuclear Chem., Supplement, 1976, 13. " ( a ) D. Naumann, H. H. Heinsen, and E. Lehmann, J. Fluorine Chem., 1976, 8, 243; ( b) K. 0. Christe, C. J. Schack, and R. D. Wilson, Inorg. Chem., 1974, 13, 2811. 88 M. Schmeisser, D. Naumann, and J. Baumanns, Z. anorg. Chem., 1975, 416, 318. 89 J. Buddrus and H. Plettenberg, Angew. Chem. Internat. Edn., 1976, 15, 436. 85 86 A. Bali and K. C. Malhotra, J. Inorg. Nuclear Chem., 1976, 38, 411. E. Lehmann, D. Naumann, and M. Schmeisser, J. Fluorine Chem., 1976, 7, 135. 91 92 J. P. Huvenne, P. Legrand, and W. Gabes, J. Mol. Structure, 1975, 27, 357. 93 R. T. Poole and J. M. Winfield, J.C.S. Dalton, 1976, 1557. 94 A. J. Edwards and P. Taylor, J. C. S. Dalton, 1975, 2174. The Halogens and Hydrogen 28 1 Figure 3 Projection of the strucrure of IF5,2SbF5 down [OOl], showing the co-ordination of (Reproduced from J.C.S. Dalton, 1975, 2174) the iodine atom compound has now been determined by X-ray methods. It may be formulated as [IF,'][Sb2FylJ, but there is strong interionic fluorine bridging (Figure 3); I - - F distances range from 2.51 to 2.94 A, whereas the average I-F (bonded) distance is 1.80 A. Spectroscopic evidence relating to the to the intermolecular forces between IF5 and MeCN or trans-[CuF,(MeCN),] has been reported by Sharp et The standard enthalpies of formation of liquid IF, and gaseous IF, have been determined by bomb calorimetry as -210.8 and -229.8 kcal m01-l .~~ At least a two-fold excess of F, was needed to convert all the I, into a mixture of IF, and IF,. The same workers have recalculated Woolf'sg7 value for Aw(IF5, liq.) and have obtained a value in good agreement with the new result. The reaction of IF5 with 02AuF6 proceeds according to reaction (12):'" the same I"" cation is produced by reaction (13). The I"" compound is a cubic phase and is structur- ally similar to IF,AsF,. a1.95 Oxides, Oxide Halides, and 0xyanions.-The oxygen and fluorine 1s binding energies of OFz have been reported by Koepke and The oxygen binding energy is 1.61 eV more positive than that of O,, and is thus the highest 0 1s binding energy known. The fluorine binding energy of OF, is higher than that of most fluorine compounds but is less than those in F2, CF,, OCF,, and ONF,. 95 J. A. Berry, D. W. A. Sharp, and J. M. Winfield, Inorg. Nuclear Chem. Letters, 1976, 12, 869. " J. L. Settle, J. H. E. Jeffes, P. A. G. O'Hare, and W. N. Hubbard, J. Inorg. Nuclear Chem., 97 A. A. Woolf, J. Chem. Soc., 1951, 231. '* N. Bartlett and K. Leary, Rev. Chim. minerale, 1976, 13, 82. 99 J. W. Koepke and W. L. Jolly, J. Electron Spectroscopy Related Phenomena, 1976, 9, 413. Supplement, 1976, 135. 282 Inorganic Chemistry of the Main-Group Elements Slivnik and co-workerslOO have described a photosynthetic route for the preparz- tion of 100g quantities of 02Fz which involves the near-u.v. irradiation of a mixture of 0, and F2 at -196°C. The electronic absorption spectra of molecular 02F, and of the radical 02F have been measured in liquid Ar and in other solvents in the region 190-600nm.10' An analysis of the data concerning the nature of the unstable violet and blue compounds that were first reported in 1962 by Streng and Grosse suggests that the colours are due to oxygen fluoride radicals, such as OzF, and not to chlorine oxide fluorides.lo2 Thus, it has now been shown that intensely coloured species are formed by 0; salts in liquid HF: these species show the same characteristics as the violet and blue 'compounds'. Laser Raman spectra have been obtained for CF30F and CF30C1 for the first time, and modified assignments of the vibrational spectra have been The e.s.r. spectra of ClOCl+and FClO' have been remeasured and analysed in detail hy Eachus and S~mons.~' The chemistry of dichlorine monoxide has been reviewed by Renard and Bloker;lo4 their review examines in particular the chemistry of this gas relating to the wood-pulp and textile industries. The literature for which abstracts have been published on chlorine oxide fluorides, between J anuary 1965 and December 1973, has been reviewed by Christe and Schack."' Oxygen-17 n.m.r. spectra have been measured at natural abundance for FClO,, ClO,, F,ClO, FClO,, and CI O,ASF,.~~~ Electrical conduc- tivity measurements and laser Raman spectra of solutions of FC10, in liquid HF suggest that the equilibrium constant for reaction (14) is 5 X lod3 mol l-'.'07 FClO, + ClOi +F- (14) The reactions of chlorine perchlorate, C10C103, with TiCl, and CrO,Cl, yield Ti(ClO,), and CrO,(ClO,),, respectively.lo8 A new method for the preparation of C1,0, has been described;"' it involves the reaction of anhydrous Mg(ClO,), with P,O,. The vibrational spectra of HClO,, in both gaseous and condensed states, have been reported and assigned by Rosolovskii et ~ 1 . ' ' ~ The unassigned e.s.r. spectra of the paramagnetic defects formed in X-irradiated KXO, (X = C1 or Br) have now been ascribed to weakly bound complexes of the type [XO,,O,] and Tantot and Bougon112 have prepared KBrO,F, by reaction (15); the salt of the [X02,2O2].' " BrF, +KBrO, + KBrO,F, +BrF, +40, (15) loo A. Smalc, K. Lutar, and J. Slivnik, J. Fluorine Chem., 1975, 6, 287. lo' N. M. Matchuk, V. I. Tupikov, A. I. Malkova, and S. Ya. Pshezhetskii, Optics and Spectroscopy, 1976, 40, 7. K. 0. Christe, R. D. Wilson, and I. B. Goldberg, J. Fluorine Chem., 1976, 7, 543. lo3 R. R. Smardzewski and W. B. Fox., J. Fluorine Chem., 1975, 6, 417. lo4 J. J. Renard and H. I. Bolker, Chem. Reu., 1976, 76, 487. lo' K. 0. Christe and C. J. Schack, Adu. Inorg. Chem. Radiochem., 1976, 18, 319. lo6 J. Virlet and G. Tantot, Chem. Phys. Letters, 1976, 44, 296. lo' C. J. Schack, D. Pilipovich, and K. 0. Christe, J. Inorg. Nuclear Chem., Supplement, 1976, 207. log N. Kolarov, R. Proinova, I. Cholakova, and M. Kalarova, God. Vissh. Khimikotekhnol. Inst., Sofia, 'lo A. I. Karelin, Z. I. Grigorovich, and V. Ya. Rosolovskii, Spectrochim. Acta, 1975, 31A, 765. '11 J. R. Byberg and J. Linderberg, Chem. Phys. Letters, 1975, 33, 612. D. Martin and G. Tantot, J. Inorg. Nuclear Chem., Supplement, 1976, 87. 107 1974, 19, 245. G. Tantot and R. Bougon, Compt. rend., 1975, 281, C, 271. 112 The Halogens and Hydrogen 283 new anion is stable up to 360°C. In the presence of F2 and a greater excess of BrF,, another oxygen is replaced, and KBrOF, is formed; this salt decomposes at 185 OC.l l 3 Both compounds were characterized by analysis, vibrational spectros- copy, and X-ray powder photography. A mixture of both salts is formed by the reaction of KBr0, and KBrF, in MeCN.l14 Gillespie and Spekkens showed that the mixture can be separated by a method which relies on the slightly greater solubility of KBrOF, in MeCN: they also re-examined the reaction of KBrO, and BrF,, and they claim that the products are FBrO, and KBrO,F,. An intimate, frozen mixture of FBrO, and excess SbF5 yields [BrOf][SbF;]1.24SbF5 when warmed slowly to room temperat~re.~'' If the mixture is inadequately homogen- ous, then reaction (16) interferes. The same reaction occurs when the bromyl salt is warmed to 80°C. The vibrational spectra of the new cation indicate that it is isostructural with monomeric SeO,. 9Br02F +SSbF, + 4[Brz][SbF;] +[BrF,+][SbF;] +90, (16) Reaction (17) has been used to prepare the new oxide fluoride of bromine(v).'l6 Vibrational spectra imply that the compound is isostructural with BrF KBrOF, +O,AsF, - KAsF, +F,BrO + O2 +iF2 (17) F3CI0. The molecular structure of gaseous FBrO, has been investigated by electron diffraction. The probable geometrical parameters are: Br-0 1.58 and Br-F 1.71w; LOBrO 115" and LFBrO 103°:117 as expected, the Br-0 and Br-F distances are shorter than those reported for BrO, (1.61A) and BrF (1.756 A). Aubke and co-workers118 have synthesized two new iodosyl compounds IO(SO,X) (X = F or CF,) by reaction (18) and an iodine(v) analogue by reaction (19). The vibrational spectra of these compounds showed that they are polymeric, 2 5 T 24h HI,O, +I, +8HS0,X SIoS0,X +3H30+ +3S0, x- (18) HIO, +2HSO,CF, + IO,SO,CF, +H,O+ +S0,CF; (19) and the presence of bridging S03X groups was inferred. Siebert and Handrichllg have re-examined and re-interpreted the vibrational spectra of PhIO, PhIO,, PhIOF,, and PhI(OCOMe),. The exchange of oxygen between iodate ions and water has been investigated by a rapid chemical-quenching technique.12' Over the pH range 2.1-12.5, exchange occurs by H'- and OH--ion-catalysed paths, and the results provide further evidence for associative substitution mechanisms with I". New direct measurements of the rate of the Dushman reaction, at [I-]< mol l-l, have been obtained and confirm the importance of the polymerization of HIO, in '13 R. Bougon, T. B. Huy, P. Charpin, and G. Tantot, Compr. rend., 1976, 283, C, 71. 'I4 R. J. Gillespie and P. Spekkens, J.C.S. Dalton, 1976, 2391. 115 E. Jacob, Angew. Chem. Inremar. Edn., 1976, 15, 158. 11' E. H. Appelman, B. Beagley, D. W. J. Cruickshank, A. Foord, S. Rustad, and V. Ulbrecht, J. Mol. 'la J. R. Dalziel, H. A. Carter, and F. Aubke, Inorg. Chem., 1976, 15, 1247. '19 H. Siebert and M. Handrich, 2. anorg. Chem., 1976, 426, 173. I2O H. von Felten, H. Gamsjager, and P. Baertschi, J.C.S. Dalton, 1976, 1683. R. Bougon and T. B. Huy, Compt. rend., 1976, 283, C, 461. Structure, 1976, 35, 139. 284 Inorganic Chemistry of the Main- Group Elements Figure 4 Proposed structure of (102F3)3 in BrF, (Reproduced by permission from Inorg. Chern., 1976, 15, 1251) aqueous solutions.121 Milne and Moffett122a have shown that IOF; is present in equilibrium with IF, and H20 (1 : 1 ratio) in MeCN, and that solutions of IF5 in hydrofluoric acid (48--100%) contain I02F2, HI02F2, HIOF4, and IF,. An earlier study had shown that no oxofluoro- or hydroxofluoro-species are present in solutions of IF5 in hydrofluoric acid.'22b Gillespie and K ras~nai l ~~ have investigated I02F, by 19F n.m.r. and Raman spectroscopy: they conclude that in solution in BrF, the compound is a cyclic trimer with cis oxygen bridges in the boat conformation (Figure 4). The molecular structure of gaseous IOF5 has been determined as a result of a combined electron-diff raction and microwave The geometrical parameters (see Figure 5) are of interest in that the axial I-F bond is longer than the equatorial I-F bonds. 0 Figure 5 Geometrical parameters for IOF, and some related molecules (Reproduced by permission from Inorg. Chern., 1976, 15, 3009) Hydrogen Halides.-The X-ray photoemission spectrum of the F 1s region of gaseous HF has been measured, using A1Kcq2 radiation.125 The spectrum was interpreted in terms of a many-electron theory with configurational interaction. The threshold photoelectron spectra of HF and DF have been reported and a number of vibronic levels of the HF+ and DF' ions have been detected.126 12' R. Furuichi and H. A. Liebhafsky, Bull. Chem. Soc. Japan, 1975, 48, 745. lZ2 ( a) J. B. Milne and D. M. Moffett, lnorg. Chem., 1976, 15, 2165; ( b ) H. Selig and U. El-Gad, J. lnorg. Nuclear Chem., 1973, 35, 3517. R. J. Gillespie and J. P. Krasznai, lnorg. Chem., 1976, 15, 1251. L. S. Bartell, F. B. Clippard, and E. J. Jacob, Inorg. Chem., 1976, 15, 3009. P. M. Guyon, R. Spohr, W. A. Chupka, and J. Berkowitz, J. Chem. Phys., 1976, 65, 1650. 123 1 2 ' R. L. Martin, B. E. Mills, and D. A. Shirley, J. Chem. Phys., 1976, 64, 3690. 126 The Halogens and Hydrogen 285 A theoretical calculation of the force field of (HF)2 has been performed127a in the light of the structure previously reported127b for this dimer. Molecular orbital calculations of the structure of solid HF are not in particularly good agreement with that observed experimentally at 4 K.128 The heat of neutralization of aqueous hydrofluoric acid has been remeasured and, hence, the value of AH," of the fluoride ion was calculated to be -80.03 f 0.08 kcal m01-1.129 Giguere has argued that the anomalously low acidity of aque- ous HF cannot be adequately accounted for by the high H-F bond strength and the stability of the HF; He has proposed that H,O-H' - - - * - F-exists as a strongly hydrogen-bonded ion pair and is a dominant species in these solutions. The 1840cm-' i.r. band can then be assigned to the out-of-plane OH bending mode of this species. The liquid-vapour equilibrium in the HF-H2S04 system has been investigated by a dynamic method over the temperature range 30-150 OC.131 The solubility of NaF in aqueous HF, 0-26 wt.%, has been determined at 60 and 72.5 OC;13, the only solid phases detected were NaF and NaHF,. The reactions of A1203 and A12(SO4)3 with gaseous HF, at 470 "C and 10-100 Torr, have been investigated by photoelectron spectroscopy and other techniques:133 although a -A1203 does not undergo a reaction in the bulk, the ratio of F:Al on the surface was shown to be 2.4:l. The electrochemical behaviour of metals in anhydrous HF has been reviewed by Vijh,134 with particular attention to anodization, open-circuit corrosion, film formation, anodic dissolution, and evolution of F,. The dependence of the F2 overpotential at Ni in anhydrous HF on the current density has been investi- gated.135 At low current densities the overvoltage was mainly due to the potential difference across the anodic barrier film, whereas at high current density the electronic conduction of the film increased appreciably, resulting in a decrease in the potential drop. Other have shown that the process of H2 discharge in HF is affected by the addition of NaF, presumably by reducing the overvoltage on nickel. The Raman spectrum of anhydrous HF has been measured over the ternpera- ture range -34 to 49°C.137 A number of weak bands were reported whose temperature dependence is consistent with the existence of a series of polymers. Liquid-solid equilibria in the binary systems MF-HF (M = Li or Na) have been studied at temperatures up to 400 "C by thermal analysis.138 The TlF-HF system 127 ( a ) L. A. Curtiss and J. A. Pople, J. MoI. Spectroscopy, 1976, 61, 1; ( b) T. R. Dyke, B. J. Howard, 12' R. W. Crowe and D. P. Santry, Chem. Phys. Letters, 1977, 45, 44. lZ9 V. P. Vasil'ev and E. V. Kozlovskii, Russ. J. Inorg. Chem., 1976, 21, 334. 130 P. A. Gigukre, Chem. Phys. Letters, 1976, 41, 598. and W. Klemperer, J. Chem. Phys., 1972, 56, 2442. B. V. Gromov, V. A. Zaitsev, V. I. Rodin, S. V. Makarov, and V. I. Bopov, Khim. Prom.& (Moscow), 1976, 286. 131 13' L. P. Belova and M. I. Mikhailova, Russ. J. Inorg. Chem., 1975, 20, 1425. 133 0. Pitton, C. K. J@rgensen, and H. Berthou, Chem. Phys. Letters, 1976, 40, 357. 134 A. K. Vijh, Surface Technol., 1976, 4, 401. 13' N. Watanabe, S. Matsui, and M. Haruta, Denki Kagaku Oyobi Kogyo Butsuri Kagaku. 1975,43,638. I. L. Serusnkin, G. A. Tedoradze, G. I. Kaurova, T. L. Razmerova, and G. P. Il'inskaya, Elektro- khimiya, 1976,12,442. 136 13' I. Sheft and A. J. Perkins, J. Inorg. Nuclear Chem., 1976, 38, 665. 13' B. Boinon, A. Marchand, and R. Cohen-Adad, J. Thermal Analysis, 1976, 9, 375. 286 Inorganic Chemistry of the Main-Group Elements was also investigated, and the following solvates were reported: TlF,nHF where n = 1, l;, 2, 3, 5, 6;, and 7.13' A group of French workers have re-examined the SbF5-HF system over the full range of they reported the existence of the adducts SbF,,nHF, where n = I, 13, 2, 3, 4, 6, and 9. The i.r. spectra of the phases with n = 1, l;, and 3 were said to be consistent with the presence of the solvated proton H2F+, whose existence has recently been under d i ~ ~ ~ ~ ~ i o n . ~ ~ ~ ~ Electrical conductivity data for solutions of MF5 (M = Nb, Ta, Mo, Re, or 0s) and M'OF4 (M' = Mo, W, or Re) in anhydrous HF show that all are relatively weak acceptors of F- The following order of acidity was deduced: OsF5 > ReF, > TaF, > MoF, > NbF, >> ReOF, > WOF4 >MoOF4. No MF, or M'OFS ions could be detected in solution by Raman spectroscopy. Conductivity measurements on solutions of PH,, H2S, and AsHa in anhydrous HF indicate that PH3 dissolves as a strong base, forming PH,', whereas H,S and ASH, are only partially i 0ni ~ed.l ~~ In the presence of TaF,, however, PH,' TaF, and mixtures of the TaF, and Ta2FTl salts of H3S+and ASH;: could be isolated. Bromine and iodine disproportionate in liquid HF in the presence of AgF to give BrF, and IF,, respectively.143 Equilibrium constants and enthalpies of formation have been determined for the 1 : 1 adducts of HF with Me2C0, MeCN, Et,O, HCONMe,, MeOH, EtOH, and THF.144 Some 1 : 1 hydrogen-bonded complexes B,HX have been studied by i.r. spectroscopy in a N2 matrix at 15 K.145 The complexes include those in which B=Me,O, X=C1 or Br; B=Me,N, X=C1 or Br; B=NH3, X=Br; B=H20, X = Br. These authors have introduced the use of a vibrational correlation diagram, which displays the relative base strength needed for proton transfer and provides a criterion for deciding when a heteronuclear hydrogen bond will involve a completely shared proton. A single crystal of HBr,2H20, weighing 130 mg, has been used in a neutron-diffraction The central 0-H-0 bridge of the H502+ ion is short, nearly linear, and not quite symmetrical (0-H distances are 1.17 and 1.22A). 2 Hydrogen Hydrogen-bonding.-Several groups of workers have performed calculations of the energies of formation of hydrogen bonds between hydrides of the first and second rows of the Periodic Table.14' The results of Kollman et al.14' are of wider interest in that, on the basis of their theoretical calculations on 25 complexes and a very simple algebraic model, they have predicted the data for a total of 144 compounds (see Table 2). 139 M. J. Boinon, G. Coffy, and A. Tranquard, Bull. SOC. chim. France, 1975, 11, 2380. ( a ) B. Bonnet, C. Belin, J. Potier, and G. Mascherpa, Compt. rend., 1975, 281, C, 1011: K. 0. Christe, C. J. Schack, and R. D. Wilson, Inorg. Chem., 1975, 14, 2224. R. T. Paine and L. A. Quarterman, J. Inorg. Nuclear Chem., Supplement, 1976, 85. 140 141 142 R. Gut, Inorg. Nuclear Chem. Letters, 1976, 12, 149. 143 J. L. Russell and A. W. Jache, J. Inorg. Nuclear Chem., Supplement, 1976, 81. 144 M. Tsuda, H. Touhara, K. Nakanishi, and N. Watanabe, J. Phys. Chem., 1976, 80, 362. 14' B. S. Auk, E. Steinback, and G. C. Pimentel, J. Phys. Chem., 1975, 79, 615. 146 R. Attig and J. M. Williams, Angew. Chem. Internat. Edn., 1976, 15, 491. 14' J. D. Dill, L. C. Allen, W. C. Topp, and J. A. Pople, J. Amer. Chem. SOC., 1975,97,7220; G. Leroy, G. Louterman-Leloup, and P. Ruelle, Bull SOC. chim. belges, 1976, 85, 229, 393. P. Kollman, J. McKelvey, A. Johansson, and S. Rothenberg, J. Amer. Chem. Soc., 1975, 97, 955. 148 3 F % 3 a 3 R m T a b l e 2 P r e d i c t e d v a l u e s o f s c a l e d h y d r o g e n - b o n d e n e r g i e s l k c a l m o l - ' t r : v E z a P r o t o n I \ 3 E l e c t r o n 1 . d o n o r % d o n o r N H 3 H 2 O N H 3 2 . 2 H 2 S P H 3 C H F 3 4 . 7 H F 1 0 . 1 5 . 5 8 . 7 H C I 3 . 6 1 . o C H 4 0 . 7 H C N 6 . 0 H N C 8 . 1 H C P 2 . 9 C H O N H , 5 . 1 C H 2 N H 3 . 4 H 2 0 H F P H 3 H , S H C l H N C H C N H C P H 2 C 0 H 2 C S H 2 N C H 0 H , C N H 8 . 3 4 . 8 5 . 6 4 . 7 2 . 8 5 . 8 5 . 5 1 . 7 6 . 2 4 . 9 1 0 . 5 9 . 1 ( 5 . 0 ) 3 . 3 3 . 2 3 . 2 2 . 0 3 . 2 3 . 0 0 . 9 3 . 4 2 . 7 5 . 7 5 . 0 6 . 6 3 . 7 4 . 3 3 . 5 2 . 0 5 , O 4 . 7 1 . 5 5 . 3 4 . 2 9 . 0 7 . 8 2 . 5 2 . 7 1 . 8 1 . 7 1 . 1 1 . 3 1 . 2 0 . 4 1 . 4 1 . 1 2 . 3 2 . 0 3 . 1 2 . 0 2 . 1 1 . 8 1 . 1 2 . 1 2 . 0 0 . 6 2 . 2 1 . 7 3 . 7 3 . 2 0 . 9 0 . 8 0 . 8 0 . 6 0 . 4 0 . 6 0 . 5 0 . 2 0 . 6 0 . 5 1 . o 0 . 9 0 . 6 0 . 3 0 . 4 0 . 3 0 . 2 0 . 4 0 . 4 0 . 1 0 . 4 0 . 3 0 . 7 0 . 6 3 . 9 2 . 2 2 . 6 2 . 2 1 . 3 2 . 7 2 . 6 0 . 8 2 . 9 2 . 3 4 . 9 4 . 2 4 . 9 2 . 9 3 . 3 2 . 8 1 . 7 3 . 4 3 . 3 1 . 0 3 . 7 2 . 9 6 . 2 5 . 4 6 . 7 3 . 8 4 . 5 3 . 8 2 . 2 4 . 7 4 . 4 1 . 4 5 . 0 3 . 9 8 . 4 7 . 3 2 . 4 1 . 4 1 . 6 1 . 3 0 . 8 1 . 7 1 . 6 0 . 5 1 . 8 1 . 4 3 . 0 2 . 6 4 . 2 2 . 4 2 . 8 2 . 4 1 . 4 2 . 9 2 . 8 0 . 9 3 . 1 2 . 5 5 . 3 4 . 6 2 . 8 1 . 6 1 . 9 1 . 6 0 . 9 2 . 0 1 . 9 0 . 6 2 . 1 1 . 6 3 . 5 3 . 1 288 Inorganic Chemistry of the Main- Group Elements A detailed account has appeared of the theory developed by Coulson and of the coupling between v(XH) and v(XH* - . Y) modes of a hydrogen-bonded complex. The theory provides strong support for the view that broad v(XH) i.r. bands owe much to contributions from combination bands of the type v(XH) f nv(XH - - - Y). However, the experimental phenomena are more pronounced than those calculated, and a discussion of other potential-energy terms which may have to be considered in a later, more refined theory is also given. Gilbert and Sheppard”’ have re-examined the i.r. spectra of KHF,, CsHF,, and HCo02, and have discussed the bandwidth phenomena in these strongly hydrogen-bonded compounds. Three crystalline forms of TlHF, exist, transition temperatures being 46.0 and 82.40C.13’ Only the higher transition was detected by n.m.r. (‘H and ”F) studies of the polycrystalline solid;151 however, it was possible to estimate the parameter x for the position of fluorine in the cubic ( a=8. 58& cell. N.m.r. spectra of polycrystalline CsHF, yield a value for the H-F distance (1.14 A) that is in good agreement with the result from neutron diffra~tion.”~ Furthermore, it was found that a sharpening of the n.m.r. signals occurs just above 58.3”C due to faster reorientation of the HF, ions in the high-temperature cubic phase. Similar studies have been performed on a single crystal of KHF,, and the H-F distance has been determined with precision, being 1.153 *0.005 The heat capacity of NH4HF2 has been measured from 5 to 450 K;154 an upward revision of the value for the enthalpy of melting was found to be necessary. The i.r. spectrum of LiOH,H20 is consistent with the presence of discrete planar, hydrogen-bonded [(OH-),(H,O),] anionic units rather than extended chains.155 Tetramethylammonium fluoride and hydroxide both form stable crystal- line monohydrates, and Harmon and Gennick have now published the i.r. spectra of these They claim that the oxygen atoms are trico-ordinate in the discrete hydrated anions. The i.r. spectra of Me4NX salts in the solid state are reported to be sensitive to the presence of hydrogen-bonding between the C-H of the cation and certain anions, such as X = F, C1, Br, I, C104, or BH4.15’ The C-H stretching region shows characteristic hydrogen-bonding shifts in such salts, especially when X = F. Perturbations are also evident in the C-H deformation and N-C breathing modes. The crystal structure of a-chloroacetic acid has revealed that it exists as a hydrogen-bonded tetramer, which allows for the presence of two non-equivalent chlorine The equilibrium constants and enthalpy changes for the 1 : 1 association reaction between chloride ion and a variety of proton donors HR have C. A. Coulson and G. N. Robertson, Roc. Roy. Soc., 1975, -2, 289. A. S. Gilbert and N. Sheppard, Spectrochim. Acta., 1976, 32A, 923. 1975, 16, 711. 149 lS1 B. D. Zil’berman, N. K. Moroz, M. Khaitova, D. D. Ikrami, and S. P. Gabuda, J. Stracr. Chem., lS2 B. D. Zil’berman, T. D. Fedetova, and S. P. Gabuda, J. Strwcr. Chem., 1976, 17, 238. lS3 P. Van Hecke, H. W. Spiess, U. Haeberlen, and S. Haussiihl, J. Magn. Resonance, 1976, 22, 93. lS4 R. W. Carling and E. F. Westrum, J. Chem. Thermodynamics, 1976,8,269; G. A. Burney and E. F. lS5 I. Gennick and K. M. Harmon, Inorg. Chem., 1975, 14, 2214. 156 K. M. Harmon and I. Gennick, Inorg. Chem., 1975, 14, 1840. lS7 K. M. Harmon, 1. Gennick, and S. L. Madeira, J. Phys. Chem., 1974, 78, 2585. ”* B. Kalyanaraman, J. L. Atwood, and L. D. Kispert, J.C.S. Chem. Comm., 1976, 716. Westrum, ibid., p. 21. The Halogens and Hydrogen 289 been determined in ~ul phol ane. ~~~ The order of increasing donor strength of HR is HCCI3 < H20 < MeOH < MeC02H < PhOH < HC02H = CF3C02H<< HCl. The crystal structure of Cs(02NOHON02) has been determined from three- dimensional, single-crystal, neutron-diff raction data.'60 The anion consists of two nitrate groups related by a very short (0 * * - H * * * 0 = 2.47 A) and symmetrical hydrogen-bond. Orientation disorder in the anion had not been recognized in the previous161 X-ray studies, and thus an apparently pseudo-tetrahedral co- ordination of the proton with 0 * - 0~2.8-3.1 A had been reported: further- more, it is conceivable that the pseudo-tetrahedral geometry of the anion re- ported for [Rh(py)4C12]H(N03)2 and (Me,N)H(NO,), is also erroneous. The structure of HN03,3H20 contains oxonium ions, each of which is bonded to two H20 molecules by short hydrogen-bonds (0 - - * H * 0 2.48 and 2.58 A) to form H70i ions;162 longer (2.80 A) bonds link H703 and nitrate groups to form a three-dimensional network. The crystal structure of CF3S03H,2H20, deter- mined by X-ray diffractometry, consists of H501 and CF,SO, ions that are hydrogen-bonded together in double 1a~ers. l ~~ In the hemihydrate, the H30+, CF,SO,, and CF,SO,H groups are bonded to form a layer structure. Short hydrogen-bonds are also a feature of the structures of Te(OH)6,NaF164 and Te(OH)6,2KF.165 Protonic Acids.-An alternative method for the measurement of the acidities of very strong protonic acids has been proposed vshich obtains estimates of the concentrations of mono- and di-protonated 'indicator', p-methoxybenzaldehyde, from n.m.r. measurements.166 An interesting feature of the results for HS03F- SbF5 mixtures, containing 8-25 mol% SbF5, is that the acidity function as measured in this fashion in the temperature range 0*20 "C is significantly more negative (see Figure 6) than had been reported earlier16' on the basis of optical measurements. The Hammett acidity functions Ho of C,F2,+lS03H have been determined conventionally;168 at 22 "C, Ho ranges from -14.1, for n = 1, to -12.3 for n = 6. Mixtures of these acids with l0h SbFS exhibited an enhanced acidity of 2.5 Ho units. HR Acidity functions have been measured for the system CF3C02H- H20 and for acid containing up to 99.5 wt.% (CF3CO),0.16g The existing data for the Ho function were corrected, and it was shown that Ho passes through its most negative value at approximately 97% acid. A comparison of the acidity function data has confirmed that although it is only a weakly protonating medium it is a strongly protonating-dehydrating agent. Cryoscopy of solutes in eutectic aqueous CF3C02H (10.6 mol.%) has shown that the average value of the cryoscopic lS9 S. Y. Lam, C. Louis, and R. L. Benoit, J. Amer. Chem. Soc., 1976, 98, 1156. 160 J. Roziere, M.-T. Roziere-Bories, and J. M. Williams, Inorg. Chem., 1976, 15, 2490. lbl J. M. Williams, N. Dowling, R. Gunde, D. Hadzi, and B. Orel, J. Amer. Chem. Soc., 1976,98, 1581. 1 6 ' I. Taesler, R. G. Delaplane, and I. Olovsson, Acra Crysr., 1975, B31, 1489. 163 R. G. Delaplane, J. 0. Lundgren, and I. Olovsson, Acra Crysr., 1975, B31, 2202. lb4 R. Allmann, Acra Crysr., 1976, B32, 1025. lC5 R. Allmann and W. Haase, Inorg. Chem., 1976,15, 804. 166 J. Sommer, P. Rimmelin, and T. Drakenberg, J. Amer. Chem. Soc., 1976, 98, 2671. 1 6 ' R. J. Gillespie and T. E. Peel, J. Amer. Chem. Soc., 1973, 95, 5173. 168 J. Groudin, R. Sagnes, and A. Commeyras, Bull. SOC. chim. France, 1976, 1779. lb9 U. A. Spitzer, J. W. Toone, and R. Stewart, Canad. J. Chem., 1976, 54, 440. 290 Inorganic Chemistry of the Main - Group Elements 21 ' 20 ' 19 ' Yo ' 18 - Ref. 166 b Ref. 167 0 5 10 15 20 25 mol % Sbq Figure 6 Acidity function H,, for the system SbF,-HF US a function of the concentration of (Reproduced by permission from J, Arner, Chem. SOC., 1976, 98, 2671) SbF, constant, Kf, is 6.53 f 0.01 "C kg m~l -';'~' however, nitric acid behaves anomal- ously, showing approximately half the expected depression of the freezing point. This result confirms the conclusions of an earlier study on the dimerization of this acid in aqueous perchloric acid. Direct physical evidence for the presence of H30+ ions in a solution has been reported by Gold and co- w~rkers. ~~~ They have assigned the 220 MHz 'H n.m.r. signals, at -7O"C, from a mixture of D,O:HSO,F:SbF, in the molar ratio 0.16: 1 :0.7, in SO, or S0,ClF as solvent, to the free acid and to HD20+ (broad multiplet), H,DO' [l : 1 : 1 triplet, J (HD) = 0.5 Hz], and H30+ (singlet). Proof of the protonation of the phosphorus(II1) halides and mixed halides, containing F, C1, or Br, has been provided by 31P n.m.r. spectroscopy: a 3: 8 volume ratio of HS03F:SbF5 in liquid SO, was used as the protonating agent.172 A polymeric super-acid catalyst has been prepared from AlC13 and macroporous sulphonated poly(styrene-divinylbenzene):'73 super-acid behaviour was shown by its action on n-hexane at 358 K. Tanabe and H at t ~r i ' ~~ have claimed that SbF5 absorbed on TiOz, Ti02-SiO,, or Si02-A1203 yields solid phases with acidities in the range -13 to -14.5: thus an acid based on Ti0,-SiO, showed the highest activity for the reaction of butane at room temperature. Miscellaneous.-An investigation of the competitive chemisorption of H2 and D2 on activated chromias at -196 "C has revealed an unusually large isotope effect of 50, favouring the adsorption of D2.17' 170 M. Ardon ahd G. Yahav, Inorg. Chem., 1976, 15, 12. V. Gold, J. L. Grant, and K. P. Morris, 3.C.S. Chem. Comm., 1976, 397. L. J. Vande Griend and J. G. Verkade, J. Arner. Chem. Soc., 1975, 97, 5958. K. Tanabe and H. Hattori, Chem. Letters, 1976, 625. R. L. Burwell and K. S. Stec, J.C.S. Chem. Comm., 1976, 577. 173 V. L. Magnotta, B. C. Gates, and G. C. A. Schuit, J.C.S. Chem. Comm., 1976, 342. The Halogens and Hydrogen 291 The evolution of H2 from a mildly alkaline suspension (pH8.Q) of Fe(OH), appears to involve elemental iron as the intermediate:176 thus 1.6 pmole of H2 were eventually generated from 100 pmole of Fe(OH),. Higher yields of H, were obtained from Fe(OH), suspensions that had beeri formed in the presence of glucose and/or nickel(I1) salts. Some of the reactions are accelerated by U.V. light. Hydrogen and oxygen have now been produced by the photochemical cleavage of water, using, as a catalyst, surfactant analogues of [Ru(bipy)J 2+: the quantum yield was estimated to be 0.1.177 Sustained photo-induced conversion of H20 into H2 and 02, using electrodes as photo-assistance agents, has recently been demon- strated, using either Sb-doped Sn02,178 reduced SrTi03,179 or reduced Ti0,18' as the photoelectrode. Criticisms and comments on the use of Pd hydride electrodes for pH measure- ments have been published.181 176 G. N. Schrauzer and T. D. Guth, J. Amer. Chem. Soc., 1976, 98, 3508. 177 G. Sprintschnik, H. W. Sprintschnik, P. P. Kirsch, and D. G. Whitten, J. Amer. Chem. Soc., 1976,98, 2337. 178 M. S. Wrighton, D. L. Morse, A. B. Ellis, D. S. Ginley, and H. B. Abrahamson, 3. Amer. Chem. Soc., 1976,98,44. 1 7 ' M. S. Wrighton, A. B. Ellis, P. T. Wolczanski, D. L. Morse, H. B. Abrahamson, and D. S. Ginley, J. Amer. Chem. Soc., 1976, 98, 2774. M. S. Wrighton, D. S. Ginley, P. T. Wolczanski, A. B. Ellis, D. L. Morse, and A. Linz, Roc. Nat. Acad. Sci., U.S.A., 1975, 72, 1518. Discussion between R. Jasinski, J. V. Dobson, et al., J. Electrochem. Soc., 1975, 122, 1634. 8 The Noble Gases BY M. F. A. DOVE 1 The Elements The structure and bonding of KrClF, a van der Waals' molecule, have been determined by molecular beam electric resonance spectroscopy: the atomic arrangement is Kr-ClF, analogous to that in ArClF, with the Kr-Cl distance Samples of Kr/F,, Xe/F,, Xe/Cl,, and Xe/Br, in an argon matrix at 20 K have been photolysed and the spectra of the photolysis products assigned to the KrF, XeF, XeCl, and XeBr molecules, respectively.' A recent report presents a detailed kinetic model for the Xe-0, system that may be useful in predicting the behaviour of this promising high-power high-efficiency laser medium.3 The struc- tures of several xenon oxide levels were determined from spectroscopic observa- tions. The model indicates that the system may operate with an efficiency as high as 6% for the 537.6 nm band and as high as 11% at 308.0 nm. 3.39 A. 2 Krypton@) and Xenon(n) More information has now been published on the preparation of adducts of KrF, with the Lewis acids AsF, (1 : 1 and 2 : 1): SbF, (1 : 2, 1 : 1, and 2 : 1) : ' and TaF, (1 : 2 and 1 : l).' Studies of thermal decomposition have produced evidence for other new adducts, e.g. [xKrF,,KrF]' M2FT1 (M = Nb or Ta), where x is probably equal to 1.' The 19F n.m.r. spectrum of Kr,gin solution in BrF, shows that the cation has a symmetrical fluorine-bridged structure like that of Xe,S. Krypton(I1) fluoride reacts with PtF, according to reaction (1). Although KrF'SbG, KrF, + PtF, + KrFPtG +$F2 (1) KrF' Sb2K1, and K rF PtE are all stable in the solid phase at room temperature, solutions of K rF SbK and K rF P c in anhydrous HF, of KrF, in SbF,, and of Kr,Ff MF; and K rF MK (M = As or Sb) in BrF5 are all unstable, and they S. E. Novick, S. J. Harris, K. C. Janda, and W. Klemperer, Canad. J. Phys., 1975, 53,2007. B. S. Ault and L. Andrews, J. Chem. Phys., 1976,65, 4192. D. L. Huestis, R. A. Gutcheck, R. M. Hill, M. V. McCusker, and D. C. Lorents, U.S.N.T.I.S., AD-A Report, 1975, No. 009284 (Chem. Abs., 1975,83, 123 895). R. J. Gillespie and G. L. Schrobilgen, Inorg. Chem., 1976, 15, 22. B. Frlec and J. H. Holloway, Inorg. Chem., 1976, 15, 1263. 292 The Noble Gases 293 decompose rapidly at room temperature according to reactions (2) and (3). When BrF, is the solvent, some oxidation to BrF,' A 1 : 1 adduct of KrF, with VF, has been shown to exist: this compound melts with decomposition at 5 " C6 (2) Kr,F,+ MF; + KrP MK + Kr + F, (3) K r F MK --.) MF, + Kr + $F2 The U.V. spectrum of XeF, has been measured accurately in the photon energy range 6-35 eV, and assignments are consistent with the ionization potentials given in the l i terat~e.~ Ab initio theoretical methods have been used to study the electronic structure of XeF,:' the bonding was found to conform quite closely with Coulson's model, viz. FXe' F-F- Xe'F. Liebmang has discussed the evidence for the existence of the XeG ion. Zemva and Slivnik have reported" the results of their studies on the thermal reaction Xe+F,+XeF, in the presence of the fluorides ScF,, FeF,, COF~, NiF,, and CuF, (group A) and TiF,, W,, CrF,, and MnF, (group B). The second group form complexes with XeF, [e.g. nXeF2,TiF4 ( n=1. 5, 1, and 0.5)11 and nXeF,,MnF, (n = 1 and 0.5)12], and thus affect the outcome as well as the kinetics of the reaction. Of the fluorides of group A, only NiF, influences the kinetics, by decreasing the activation energy from 22 kcal mo1-l to 14 kcal mol-l.lo Gillespie, Landa, and S~hrobilgen'~ have proposed that the order of ability of the binary xenon fluorides to donate a fluoride ion is XeF,<XeF,<XeF6, thus interchang- ing the previously accepted positions of XeF, and XeF,. The basis of their arguments is an analysis of the length, direction, and number of fluorine bridges formed between cation and anion in salts of XeE,,-, (n = 1, 2, and 3). They argue that the lower thermal stability of salts of X es is not a good criterion of the acceptor strength for F- of this cation, which will depend on a number of other factors, e.g. the lattice energies of the crystalline solids. Additional 12'Xe n.m.r. spectroscopic data have been obtained by the F.T. technique on a range of compl exe~:~~ a striking correlation was revealed between the Xe shift and the 19F shift for the terminal fluorine(s) of FXeZ (Z = F, S03F, FMoOF,, or FWOF,) and of (FXe),Z' (Z' = S 0 3 F or F). The X-ray structure of XeF2,2SbF, has now been refined and the geometry around the X eF cation has been ~onfirmed.'~ In addition, there is evidence for a weak F-bridge (Xe-F = 3.06 A), which is also reflected in the distortions of the Sb2F;1 group. Measurements of the heat of hydrolysis of this adduct were also reported, and a standard heat of formation (-705 kcalmol-l) was inferred. B. Zemva, J. Slivnik, and A. Smalc, J. Fluorine Chem., 1975,6, 191. P. S. Bagus, B. Liu, D. G. Liskow, and H. F. Schaefer, J. Amer. Chem. Soc., 1975, 97, 7216. J. F. Liebman, J. Fluorine Chem., 1976, 7, 531. ' U. Nielsen and W. H. E. Schwarz, Chem. Phys., 1976, 13, 195. lo B. Zemva and J. Slivnik, J. Inorg. Nuclear Chem., Supplement, 1976, 173. 'I B. Zemva, J. Slivnik, and M. Bohinc, J. Inorg. Nuclear Chem., 1976, 38, 73. l2 M. Bohinc, J. Grannec, J. Slivnik, and B. Zemva, J. Inorg. Nuclear Chem., 1976, 38, 75. l 3 R. J. Gillespie, B. Landa, and G. J. Schrobilgen, J. Inorg. Nuclear Chem., Supplement, 1976, 179. l4 J. H. Holloway, G. J. Schrobilgen, P. Granger, and C. Brevard, Compt. rend., 1976,282, C, 519. Is J. Burgess, C. J. W. Fraser, V. M. McRae, R. D. Peacock, and D. R. Russell, J. Inorg. Nuclear Chem., Supplement, 1976, 183. 294 Inorganic Chemistry of the Main-Gbup Elements Raman spectral6 and electrical conductivity data17 for the molten adducts of XeF, with MF, (M=Sb, Nb, or Ta) show that the compounds are only weakly ionized in the melts. A 2: 1 mixture of XeF, and AuF, in liquid HF yields18 a precipitate which is isomorphous with Xe,e IrF;. Russian workers have reportedlg that nickel salts can be oxidized to N@- with XeF,; however, in liquid HF at or below room temperature, NiN, Cow, and Cu"' will convert elemental Xe into XeF,.'' Brown et al. have shown that CrF5,2SbF5 will react with xenon, but not with krypton, to form a product which they formulate as Xe(CrF4Sb2F11)2.21 Bartlett and co-workersZ2 have investigated some reactions of molten XeF,, and their results are summarized in reactions (4) and ( 5) : a spectroscopic study of the complexes XeM2F10 (M = Pd or Pt) indicates that 145 "C 70 "C, vacuum 155 "C SXeF, + 2PtF4 2Xe,F3PtF6 2XeFPtF6 XeF#Flo (4) -XeFz 145 "C 145 'C 280 "C 3XeF, + Pd,F6 - 2XePdF6 XePd,F,, -xeF,c PdzF6 ( 5) -Xe both are salts of X eF and a polymeric (M2F9)E- anion. Xenon(n) fluoride is intercalated in graphite in the presence of liquid HF at 22°C to form C17,XeF2,1 .3HF.23 Primary and secondary phosphines undergo24 simple fluorination reactions with XeF,; although PH bonds were unaffected, PCl, SiS, and SiN centres were attacked. Phenyl methyl sulphide in CH,C1, is fluorinated by XeF, in the presence of HF to form the fluoromethyl and, eventually, the difluoromethyl analogues.25 Ring fluorination occurs with XeF, for pyridine, quinoline, and aniline deri- vatives;26 however, iodobenzene derivatives undergo fluorination at the iodine to form C6H5& and related compounds.27 The determination of the crystal structure of F,SeOXeOSeF, has confirmed the expected molecular geometry:28 the monomeric units have the OXeO and SeOXe angles 180" and approximately 125", respectively, although disordering of the 0 and F atoms has made it impossible to determine certain parameters with saci ent accuracy. Xenon(I1) chloride, isotopically enriched in 136Xe, has been l6 B. Frlec and J. H. Holloway, J. Inorg. Nuclear Chem., Supplement, 1976, 167. l7 J. Fawcett, B. Frlec, and J. H. Holloway, J. Fluorine Chem., 1976, 8, 505. " M. J. Vasile, T. J. Richardson, F. A. SteVie, and W. E. Falconer, J.C.S. Dalton, 1976, 351. l9 Yu. I. Nikonorov, V. N. Mit'kin, Yu. V. Chumachenko, and S. V. Zemskov, Izvest. Sibirsk. Otdel. 2o T. L. Court and M. F. A. Dove, J. Fluorine Chem., 1975, 6, 491. " S. D. Brown, T. M. Loehr, and G. L. Gard, J. Fluorine Chem., 1976,7, 19. 22 N. Bartlett, B. Zemva, and L. Graham, J. Fluorine Chem., 1976, 7, 301. 23 A. V. Nikolaev, A. S. Nazarov, and V. G. Makotchenko, Izvest. Sibirsk. Otdel. Akad. Nawk S.S.S.R., 24 J. A. Gibson, R. K. Marat, and A. F. Janzen, Conad. J. Chem., 1975, 53, 3044. " M. Zupan, J. Fluorine Chem., 1976, 8, 305. 26 S. P. Anand and R. Filler, J. Fluorine Chem., 1976, 7, 179. " M. Zupan and A. Pollak, J. Fluorine Chem, 1976, 7, 445. '' L. K. Templeton, D. H. Templeton, K. Seppelt, and N. Battlett, Inorg. Chem., 1976,15,27t8. Akad. Nauk S.S.S.R., Ser. khim. Nauk, 1976, 79. Ser. khim. Nauk, 1976,62. The Noble Guses 295 synthesized for matrix-Raman and -i.r. have been identified; however, the bending mode v, has eluded observation. v1 and v3 of the XeCl, molecule 3 Xenon(rv) The photosynthesis of XeF, at room temperature from Xe and a modest excess of F, has been accomplished in borosilicate glass.3o Under these reaction conditions the formation of XeF, was complete in less than 2 h, and the conversion into XeF, required about 36 h. The U.V. spectrum of XeF, has been remeasured and the first two ionization potentials have been re-assigned as uZu 13.06eV and a,, 13.4 eV.7 Two modifications of X eg SbK and one of X eg Sb2K1 have been charac- terized by Raman spectro~copy:~~ the analogous compound with As2F1 was not detected, and the ASK salt was found to be thermally unstable. The 129Xe n.m.r. spectrum of X eg shows a resonance 342p.p.m. downfield from XeF,, with the expected Xe-F coupling constant^.'^ Xenon(Iv) fluoride intercalates with graphite to give C,,,XeF, or C,1,XeF4, depending on the type of graphite Intimate mixtures of XeF, and H20 (1 : 1.1 molar ratio) transform into XeOF, at temperatures between -80 and -50°C.33 The product is stable up to -25" C, above which temperature it disproportionates [reaction ( 6) ] . In contact with SbF,, AsF,, or mercury, it decomposes explosively. 2XeOF, -+ XeO,F, + XeF, (6) 4 Xenon(vr) The evidence for the molecular structure of XeF, has been reviewed by Pitzer and Bern~fein:~, they concluded that there is no reason to question the proposal that the structure arises from a pseudo-Jahn-Teller effect associated with the relatively low energy of excitation of a 5s electron to a 5p level. In the presence of NiF, it is possible to synthesize XeF6 from Xe and F2 (molar ratio 1 : 5 ) even at 120 "C.l0 Intercalation of XeF6 in graphite at room temperature yields C19XeF6:35 only a trace of xenon was liberated during the reaction. Thermal decomposition begins at 8O"C, and is rapid at 450°C. No xenon compounds could be recovered in this way. A number of new adducts containing XeF, have been reported: nXeF,,- MF, (n=4, 1, or 0.5) for Ti" and Mn," as well as 2XeF6,MnF4;l2 XeF6,M'F3 (M'=Fe or CO) ~ , have been synthesized by the reaction of excess XeF, with the hydrazinium fluorometallates [the adduct with iron(rI1) is antiferromagnetic]. 29 I. R. Beattie, A. German, H. E. Blayden, and S. B. Brumbach, J.C.S. Dalton, 1975, 1659. 'O A. Smalc, K. Lutar, and J. Slivnik, J. Fluorine Chem., 1976, 8, 95. '' R. J . Gillespie, B. Landa, and G. J . Schrobilgen, I v r g . Chem., 1976, 15, 1256. 32 H. Selig, M. Rabinovitz, I. Agranat, and C. H. Lin, J. Amer. Chem. Soc., 1977,99,953. '' E. Jacob and R. Opferkuch, Angew. Chem. Intemat. Edn., 1976, 15, 158. 34 K. S. P i e r and L. S. Bernstein, J. Chem. Phys., 1975, 63, 3849. '' H. Selig, M. Rabhovitz, I. Agranat, C. H. Lin, and L. Ebert, J. Amer. Chem. Soc., 1976,98,1601. 36 J. Slivnik, B. Zemva, M. Bohinc, D. Hanzel, J. Grannec, and P. Hagenmuller, J. Inorg. Nuclear Chem., 1976, 38,997; D. Hanzel, Inorg. Nuclear Chem. L.?k?rs, 1976,12,539. 296 Inorganic Chemistry of the Main-Group Elements Niobium(v) fluoride reacts with excess XeF, to give 2XeF6,NbF5?' which decom- poses in vacuo at room temperature to the 1 : 1 adduct; i.r. spectra of the adducts indicate the presence of Xe,cl and X es ions, respectively. Vibrational spectra of X ec as its derivatives with BK and As 5 have been discussed in detail by Christe et aZ.;38 force-field calculations for the isoelectronic series MF, (M = Xe', I, Te-, or Sbz-) were carried out to assist with the assignments. Xenon F.T.n.m.r. spectra for XeG and X eOc have been obtained which show the expected 129Xe-'9F coupling ~0nstants.l~ Raman spectra31 of the adducts of XeOF, and Xe02F2 with SbF, are said to be in good agreement with the presence of the trigonal-bipyramidal (0 and lone-pair equatorial) XeOg and pyramidal Xe0,F' ions. The XeOF4-PtF, system, in sapphire reactors, has been i n~esti gated:~~ oxygen is liberated, and both X ec and 0; l et5 were shown to be present in the residue. The compound XeOF,.,,XeCPtG was formed in the presence of an excess of XeOF,. " B. Zemva and J. Slivnik, J. Fluorine Chem., 1976, 8, 369. 38 K. 0. Christe, E. C. Curtis, and R. D. Wilson, J. Inorg. Nuclear Chem., Supplement, 1976, 159. 39 K. 0. Christe and R. D. Wilson, J. Fluorine Chem., 1976, 7, 356. Author Index Aaby, S., 221 Abalyaeva, V. V., 173 Abdel-Gawad, F. M., 35 Abel, E. W., 155 Abend, G., 237 Abicht, H. P., 193 Abraham, K. M., 189, 222 Abrahamson, H. B., 291 Abramova, E. L., 179 Abramowitz, H., 111 Abramowitz, S., 198 Adair, R. R., 109 Adamietz, J., 217 Adams, D. M., 123 Adams, J . M., 95, 124 Adams, M. J., 9 Adams, P. F., 2 Adams, R. D., 153, 154 Adcock, J . L., 272 Addison, C. C., 5, 173 Adhikari, S. K., 44 Adler, O., 223, 224 Ado, G., 14 Adolphson, D. E., 226 Afanas’ev, Yu. A., 17, 36 Agevnin, M. R., 98 Aghai-Khafri, H., 18 Agranat, I., 113, 295 Aharoni, C., 113 Ahluwalia, J . C., 15 Ahmed, F. R., 210 Ahmed, M. G., 271 Airon, D. K., 230 Ajello, J . M., 115, 116 Akitt, J . W., 8, 92 Aksnes, D. W., 224 Albright, M. J ., 27, 91 Alcock, N. W., 129, 130, 278 Aldridge, J . P., 238 Aleksakhan, K. A., 106 Alekseeva, L. S., 56 Aleonard, S., 41 Alexander, I., 5 Alexander, W. A,, 6, 103 Alford, K. J .,-77 Aliev, R. Ya., 180 Alikhanyan, A. S., 77 Alistar, A., 175 Allamandola, L. J., 43, 56 Allan, C. T., 9 Allavena, M., 251 Allcock, H. R., 206, 207, 209 Allen, L. C., 286 Allinson, J . S., 150 Allman, R., 267, 289 Almenningen, A., 62 Altmann, J. A., 198 Aly, F. A., 35 Alymov, I. M., 103 Amberger, E., 88 Amer, F. A., 224 Amosov, V. M., 95 Anacker-Eickhoff, H., 107 Anand, B. N., 27 Anand, S. P., 294 Anbar, M., 184 Anderson, A. B., 172 Anderson, J . S., 235 Anderson, R. A., 155 Anderson, S., 54 Anderson, T. J ., 91 Anderson, J ., 160 Anderson, J . E., 107, 219 Andreasen, H. A., 16, 17, 264 Andreeva, M. A., 209 Andreikov, E. I., 255 Andresen, A. F., 221 Andrews, L., 276, 277, 292 Ang, T. T., 73 Angyal, S. J ., 49 Anker, M. W., 174 Annarelli, D. C., 158 Ansari, S., 195 Ansell, G. B., 122 Antoniou, A. A., 112 Antonov, P. G., 156 Antonova, L. T., 269 Anundsk%s, A., 102 Aoyagi, T., 30 Appel, R., 116, 192, 200, 203, Appelman, E. H., 283 Araki, S., 143 Arazova, L. A., 8 Ardon, M., 184, 290 Aresta, M., 175 238, 243, 246, 250, 252 Arlyukhov, A. A., 182 Armatis, F. J., 226 Armor, J . N., 177 Armstrong, R. S., 119 Amdt, J., 97 Arnold, D. E. J ., 75, 196, 201 Amold, D. P., 149 Aronson, S., 112, 273 Arsene, J., 101 Asai, K., 125 Ashby, E. C., 40 Ashe, A. J., 83 Ashi, G. E. M., 139 Asprey, L. B., 272 Atake, T., 116 Atchekzai, H., 82 Atkinson, R., 114 Attar-Bashi, M. T., 119 Attig, R., 210, 236, 286 Attwood, D., 244 Atwood, J . L., 90,91, 96, 288 Aubke, F., 253, 278, 283 Aubry, J., 37, 176 Auger, Y., 255 Ault, B. S., 277, 286, 292 Aurivillius, B., 219, 231 Ausloos, P. J ., 273 Austin, E. R., 118 Autrusseau-Duperray, M. H., Autzen, H., 213 Avdeev, V. I., 175 Averbuch-Pouchot, M. T., Axtell, D. D., 125 Aylett, B. J., 150 Aymonino, P. J ., 225 Azarian, D., 148 Azarova, L. A., 78 Azhdarova, D. S., 257 Azzaro, M., 76, 191 186 132, 216 Babaeva, B. K., 104, 262 Babel, D., 97 Babin, M., 201 Babitsyna, A. A., 262 Babkina, N. A., 100 Babu, Y. S., 208 297 298 Author Index Bachhuber, H., 180 Back, R. A., 118 Baddiel, C. B., 9 Bahr, W., 231 Baert, F., 98 Baertschi, P., 283 Batzel, V., 150 Baumer, G., 192 Bagus, P. S., 293 Bahe, L. W., 8 Baidina, I. A., 136 Baier, H., 221 Baierl, P., 273 Bakakin, V. V., 136 Baker, J . A., 113 Bakhitov, M. I., 164 Bakos, A., 75 Balch, A. L., 45 Balchin, A. A., 49 Baldwin, W. H., 1 Balej, J., 255 Bali, A., 255, 280 Ballard, D. G. H., 90 Ballard, J . G., 229 Balszuweit, A., 227 Bamberger, C. E., 273 Bamgboye, T. T., 210 Banck, K., 210 Bancroft, G. M., 134, 154 Banister, A. J ., 137 Bansal, K. M., 238 Baran, E. J ., 225 Baranyi, A. D., 161, 162 Barbier, P., 98, 105 Barbieri, R., 129, 131, 272 Barchuk, V. T., 41 Bardin, J . C., 13 Barker, G. K., 67 Barker, M. G., 4, 5 Barnes, J . C., 46, 138 Barnett, A. E., 239 Barnir, Z., 113 Barraclough, P. B., 40 Barrow, D. F., 114 Bars, O., 259 Bart, J . C. J ., 260 Bartell, L. S., 197, 284 Barthelat, J . C., 119 Bartlett, N., 281, 294 Barton, S. S., 112 Barton, T. J., 146 Basch, H., 235 BaSe, K., 61, 63 Bashilov, V. V., 156 Bassler, H. J., 199 Bastide, J ., 83 Bastow, T. J ., 102 Bates, J . B., 123 Batsanov, S. S., 107, 234 Baucher, A., 78 Baudis, U., 233 Baudler, M., 189, 190, 218 Bauer, G., 146 Bauer, J ., 89 Bauer, S. H., 114 Baumann, N., 229, 232 Baumanns, J ., 280 Baur, W. H., 141, 258 Bayanov, A. P., 17, 36 Bayard, M., 262 Bayha, H., 77, 193 Beachley, 0. T., 74, 91 Beagley, B., 145, 283 Beall, H., 58, 62 Beattie, I., 266 Beattie, I. R., 97, 295 Beattie, W. H., 275 Beaucage, S. L., 214 Beaudet, R. A., 60, 61,237 Beck, J . D., 98 Becker, G., 195 Becker, H. J ., 83, 195 Begley, M. J. , 210 Beguin, F., 113 Begun, G. M., 95 Behrendt, D., 217 Belin, C., 184, 286 Belinskaya, F. A., 232 Bell, A. T., 13, Belonogova, A. K., 52 Belova, L. P., 285 Belyakov, T. I., 271 Belyuga, Y. V., 262 Bemand, P. P., 271 Beneke, K., 217 Ben Ephraim, A., 15 Bennett, M. R., 18 Benoit, R. L., 289 Bentham, J ., 5 Benzinger, W. D., 166 Berenzhanov, B. A., 255 Beremzhanov, V. A., 253 Berezhnaya, V. T., 41 Berger, A. S., 101 Berger, H. O., 72 Berger, R., 221 Bergerhoff, G., 222 Bergesen, K., 224 Bergman, A. G., 255 Berkowitz, J ., 284 Bernado, C., 11 1 Bernstein, L. S., 198, 295 Berry, J . A., 281 Bertaut, E. F., 141, 258 Bertazzi, N., 129, 131, 227 Berthou, H., 285 Bertin, F., 45 Besenhard, J . O., 113 Betowski, L. D., 118 Bevan, P. C., 175 Beyreuther, C., 88 Bhasin, K. K., 230, 259 Biddlestone, M., 202, 208 Binder, M., 273 Binenboym, Y., 113 Binger, P., 60 Binnewies, M., 105, 263 Biordi, J . C., 115 Birchall, T., 226, 229, 232 Birke, G., 230 Birkofer, L., 116 Biryukov, V. A., 15 Bishop, E. O., 77 Bishop, M. E., 144 Bitter, W., 200 Bjerrum, N. J ., 16, 17, 264 Blachnik, R., 16 Black, M., 59, 60 Blackborow, J . R., 94, 162 Blanchard, J . M., 14, 257 Blanck, K., 216 Blaschette, A., 241 Blayden, H. E., 97, 295 Bleckmann, P., 145 Bleidelis, Y. Y., 129 Blick, K. E., 86 Block, E., 251 Block, J . H., 237 Boate, A. R., 277 Bochkarev, M. N., 156 Bock, H., 83, 119,251 Bockerman, G. N., 198 Bodenseh, H. K., 277 Bodkin, C. L., 49 Bodnarchuk, N. D., 199 Bodner, G. M., 63 Bohn, W., 190 Boer, F. P., 51 Bogatov, Yu. E., 106, 267 Bogatyreva, T. A., 95 Bohinc, M., 293, 295 Bohm, P., 86 Bohme, D. K., 117, 118 Boinon, B., 285 Boinon, M.-J ., 107, 286 Boivin, J . C., 233 Bojes. J ., 247 Boldrini, P., 263 Boldyrev, A. I., 175 Boleslawski, M., 94 Bolker, H. I., 282 Bol’shakova, N. K., 96, 260, 267, 268 Bondar, 1. A., 216 Bonix, J., 222 Bonnet, B., 228, 286 Bonnetain, L., 113 Bonomo, F. S., 272 Boorman, P. M., 247 Borel, M. M., 51 Borgoyakov, V. A., 268 Boriakova, V. A., 262 Borisov, E. A., 180 Borisov, S. V., 136 Borodulenko, G. P., 258 Borukhov, I. A,, 185 Bos, K. D., 148 Bosmans, H. J ., 95 Bosson, B., 107 Botto, I. L., 225 Bottomley, F., 175 Boudjada, A,, 216 Author Index 299 Bougon, R., 282, 283 Bouix, J., 262 Bouloussa, O., 215 Bourke, J. D., 19 Bousquet, J., 14, 257 Bovin, J .-O., 231 Bowen, L. H., 228 Bowers, M. T., 115 Bradaczek, H., 250 Bradford, C. M., 272 Bradley, E. B., 86 Bradshaw, J . S., 21 Bramer, W., 6 Brandau, D., 102 Brand], A., 175, 178 Brandt, W., 203 Bratt, P. J ., 74 Brattsev, V. A., 62 Braun, R. W., 199 Braun, W., 12 Brawer, S. A., 123 Bray, P. J ., 79 Breakspere, R. J ., 39 Breazeale, J . D., 272 Brec, R., 259 Bregadze, V. I., 62, 99 Brendhaugen, K., 56 Bresadola, S., 70 Brevard, C., 293 Breysse, M., 235 Brice, J . F., 176 Brice, V .T., 59 Briggs, R. W., 106 Briggs, T. S., 179 Bright, A. A., 244 Bright, D., 25 Brissey, G. M., 119 Brittain, H. G., 48 Brockington, R., 229, 252 Broers, G. H. J ., 13 Bronger, W., 6, 258 Brooker, M. H., 41 Brooks, J . N., 272 Brooks, W. F. V., 264 Bros, J . P., 18 Brower, F. M., 89 Brown, A. J ., 93 Brown, C. W., 251 Brown, F. R., 82 Brown, I. D., 263 Brown, J ., 74 Brown, J . E., 119 Brown, M. P., 74 Brown, R. S., 236 Brown, S. D., 200, 294 Brown, T. L., 151 Brown, W. E., 165 Briiser, W., 73 Brumbach, S. B., 295 Brunel-Laugt, M., 165, 216 Brunette, J . P., 230 Bruning, D., 39 Brunvoll, J., 237, 278 Brupbacher, J. M., 117 Brumne, G., 37 Bryukhova, E. V., 103 Bryushkova, N. V., 8 Buben, S. N., 272 Bubnova, L,. B., 268 Buck, R. P., 273 Buddrus, J., 280 Budenz, R., 240 Buder, PI., 204 Bues, W., 260 Bugg, C. E., 49 Bukhalova, G. A., 41, 217, Bukovszky, A., 266 Bulbulian, S., 263 Bullen, G. J., 207 Bulloch, G., 205 Bulmer, J . T., 46 Bulten, E. J., 135, 148 Burdina, K. P., 178 Burgard, M., 230 Burgess, J., 293 Burks, T. L., 115 Burlakova, V. M., 41 Burlqy, J . W., 136, 143 Burney, G. A., 288 Burschka, C., 258 Bursill, L. A., 101 Burton, C. A., 256 Burwell, R. L., 290 Burylev, B. P., 16 Busby, D. C., 175 Buscarlet, E., 113 Busch, B., 137 Buschow, K. H. J., 6, 36 Busetto, C., 90 Bush, M. A., 25 Bushweller, C. H., 58 Buslaev, Yu. A., 214 Buss, B., 231 Buss, W., 243 Butler, W. M., 27, 91 Butsko, S. S., 255 Byberg, J. R., 282 Byler, D. M., 230, 252 255 Cabana, A., 72 Cable, R. A., 174 Calabrese, J . C., 43, 58 Calhoun, H. P., 211 Callaway, B. W., 238 Callaway, J . O., 102 Calleri, M., 124 Calvert, L. D., 6, 103, 233 Calves, J . Y., 229 Calvo, C., 217, 218 Cameron, J . D., 277 Cameron, T. S., 29, 208, 211 Campbell, A. B., 255 Campbell, A. N., 103 Campbell, B. S., 215 Caminati, W., 228 Cancela, R. J., 186 Capezzuto, P., 117 Capponi, J . J., 79 Caramazza, R., 8 Carling, R. W., 288 Carlsohn, B., 190 Carlsson, B., 188 Carpy, A., 261 Carre, J ., 272 Carroll, W. E., 70 Carsten, K., 83 Carter, H. A., 283 Carter, R. L., 253 Cartwright, M., 135 Castenet, R.,, 36 Castle, J . E., 109 Catsikis, B. D., 272 Catti, M., 216 Caullet, P., 95, 124 Caulton, K. G., 190 Cauquis, G., 270 Cavell, R. G., 198 Cawet, G., 256 Cazzoli, G., 228 Centofanti, L. F., 191 Ceolin, R., 233, 258 Cermak, V., 254 Cernik, M., 187, 260 Cervell, B., 78 Chadha, S. L., 230 Chaikin, A. M., 272 Chaivanov, B. B., 182 Chakravorty, D., 28 Chan, S. I., 24 Chanin, L. M., 182 Chanussot, J ., 277 Chapput, A., 85 Chaput, G., 30 Charpentier, C. D., 104 Charpin, P., 283 Charrin, L., 36 Chatt, J ., 174, 175 Chatterji, D., 112 Chau, M., 115 Chaudhry, S. C., 80, 229 Chaudhuri, N. R., 51 Chawla, 0. P., 253 Chen, M. M., 195 Cheng, C. J ., 11 Chernaplekova, V. A., 135 Chernitsyna, M. A., 262 Chernorukov, N. G., 225 Chernov, A. P., 269 Chernykh, S. M., 267 Chevel’kov, V. F., 262 Chevalier, R., 102 Chevy, A., 102 Chheda, G. B., 31 Chi, H., 93 Chiarizia, R., 26 Chibirova, F. Kh., 101 Chicagov, Yu. V., 277 Chihara, H., 116 Chikanov, M. K., 259 Chiotti, P., 7 Chipperfield, J . R., 152 300 Author Index Chiusano, M. A., 74 Chivers, T., 132, 213, 247 Choisnet, J ., 123 Cholakova, I., 282 Chou, N. J., 125 Choudary, U. V., 172 Christe, K. O., 136, 187, 198, 237, 278, 279, 280, 282, 286, 296 Christensen, J . J ., 21 Christie, J . R., 122 Chubar, B., 173 Chukov, S. P., 257 Chumachenko, Yu. V., 294 Chung, C., 28 Chung, H. L., 103 Chupka, W. A., 284 Churbanov, M. F., 237 Cizek, M., 255 Clapp, C. H., 214 Clardy, J . C., 214 Clark, G. R., 191 Clark, J . H., 275 Clark, W. W., 114 Clarke, J . B., 258 Clarke, R. J . H., 119 Clarkson, S. G.,’ 175 Claudel, B., 235 Clayton, W. R., 48, 55, 58, 59 Clearfield, A., 217 Cleland, J ., 16 Clementi, E., 8 Clifford, A. F., 240 Clifford, J . O., 13 Cling, C. F., 36 Clippard, F. B., 284 Clyne, M. A. A., 235, 271 Cobbledick, R. E., 201 Cocke, D. L., 172, 237 Cody, I. A., 120 Coe, D. A., 44, 56 CotTy, G., 107, 108, 286 Coggiola, M. J ., 272, 276 Coghi, L., 131 Cohen, M. J ., 244 Cohen-Adad, R., 285 Coker, H., 8, 14 Colarnarino, P., 166 Colbourn, E. A., 272 Collins, C. B., 116 Collins, M. P. S.. 235 Colomer, E., 150, 154 Colquhoun, H. M., 150 Comasseto, J . V., 270 Commeyras, A., 289 Compton, R. N., 117 Conaway, B., 114 Condon, J . B., 88 Conflant, P., 233 Connor, J . A., 226 Contreras, J . G., 105 Cook, T. H., 44, 56 Cook, W. J ., 49 Cool, T. A., 116 Coon, V. T., 116 Cooney, R. P., 161 Cooper, C. D., 117 Copeland, J . L., 18 Coray, G. M., 194 Corazza, E., 79 Corbett, J . D., 172, 226 Cornwell, A. B., 163, 168, 169 Cornwell, C. A., 163 Corriu, R., 150, 154 Costa, C. M., 256 Cot, L., 159, 216 Cotton, J . D., 153, 170 Couch, D. A., 93 Coudurier, M., 119 Couldwell, M. C., 154 Coulson, C. A., 288 Coulson, D. R., 157 Couret, C., 145 Court, T. L., 294 Courtois, A., 37 Coutts, J . W., 14, 40, 257 Cowley, A. H., 199, 240 Cox, A. W., jun., 192 Cradock, S., 119 Craig, R. S., 116 Cramer, J . A., 271 Crane, G. R., 217 Creffield, G. K., 5 Cremaschi, P., 28 Crocombe, R., 266 Cross, R. J ., 201, 270 Crowe, R. W., 285 Cruickshank, D. W. J ., 283 Csakvan, B., 125 Csizmadia, I. E., 198 Cucinella, S., 90 Cueilleron, J ., 55 Curlander, P. J., 101 Curtis, E. C., 198, 237, 278, Curtis, M. D., 147, 153 Curtiss, L. A., 285 Cynane, M. J. S., 170 Cyvin, B. N., 141 Cyvin, S. J., 141, 237, 278 Czarnowski, J ., 240 Czisa, G., 75 296 Dachille, F., 168 Dadashev, M. M., 104, 269 Dagenais, M., 272 D’Agostino, R., 117 Dahl, A. R., 196 Dalgleish, W. H., 205 Dalziel, J . R., 283 Damien, D., 269 D’Amour, H., 217 Danby, C. J ., 115 Danen, W. C., 243 Danes;, P. R., 22, 26 Danilova, G. N., 62 Dann, P. E., 207 Danot, M., 259 D’Antonio, P., 114 Darriet, J ., 102 Dartyge, J . M., 218 Das, S. K., 116 Dash, A. C., 94 Datta, R., 11 David, J., 37, 188 Davidson, I. M. T., 157 Davidson, P. J ., 169, 170 Davies, I., 270 Davies, R., H., 192 Davis, B. R., 215 Davis, D. D., 114 Dawson, A. P., 5 Dawson P., 254 Dazord, J ., 55, 82 Dean, W. K., 154 De’ath, N. J ., 199, 215 Debeau, M., 237 de Boer, E., 21 Debuigne, J ., 89 Dechter, J. J., 107 De D. Lopez-Gonzalez, J., Deeg, T., 93 Deganello, S., 14 Degens, H. M. L., 21 de Graff, R. A. G., 41 Degtyarev, A. N., 62 Dehaven, P. W., 229 Dehnicke, K., 86, 137, 180, Deichman, E. N., 104, 217, Deiseroth, H. J., 12 de Jong, J . M., 13 de Kozak, A., 13 Delaplane, R. G., 289 Delf, M. E., 157 Delimarskii, Yu. K., 17 Deller, K., 38, 220, 226 Del Mar, E. G., 194 Del’Pino, I#., 186 De Lucia, F. C., 114 Dembovskii, S. A., 269 Dement’eva, V. F., 275 Demidenko, N. V., 213 Demidov, A. I., 7 Demuth, R., 134, 195 Deneken, L., 280 Denisov, N. T., 173 Denisov, Yu. N., 106 Denney, D. B., 199, 215 Denney, D. Z., 199, 215 Denniston, M. L., 55,74,270 Dent Glasser, L. S., 122 Denton, D. L., 48, 58 De Panafieu, A., 181 Dergunov, Yu. I., 148 Derlyukova, L. E., 251 Derr, H., 102 Derriche, Z., 166 de Ruiter, B., 212 Deryagin, B. V.. 109 112 227, 280 260 Author Index 301 de Sallier-Dupin, A., 218 Deschampes, A., 123 Desideri, A., 172 Desmarteau, D. D., 197 Desnoyers, C., 102 de Stefano, A., A., 86 Detellier, C., 29 Devarajan, V., 79 Devaud, M., 125 Devyatykh, G. G., 237 Dewan, J . C., 228 de With, G., 46 De Witt, R., 35 de Witte, W. J., 8 Dewkett, W. J., 58 Dhillon, D. S., 255 Dickens, B., 165 Diedrich, K. M., 189 Diehl, L., 172 Diehl, R., 104 Diem, M., 114 Dienstbach, F., 16 Dietl, M., 243 Dietz, E. A., 76, 190 Dill, J . D., 286 Dillard, J . G., 238 Dillemuth, F. J., 115 Dillon, K. B., 192, 199 Dillon, M. G. C., 192 Dilworth, J. R., 175 Dines, M., 178 Diop, L., 184 Distefano, E. W., 59 Ditter, J. F., 60 Dittmar, G., 141, 262 Djahanguiri, P., 228 Doak, G. O., 199 Dobbie, R. C., 59, 60, 191 Dobryanskaya, L. P., 255 Dobson, J . V., 291 Dock, C. H., 7 Dodds, A. R., 74 Dodson, A., 178 Dolan, P. J., 57 Domanskii, A. I., 216 Domenichini, C., 26 Donaldson, J . D., 164, 170, Donnay, G., 162 Donnet, J . B., 119 Donohue, J., 146 Donoghue, M. T., 164 Donovan, D. J., 229, 241 Donovan, R. J., 273 Dorkhov, V. A., 85 Dorn, W. L., 266 Dornfeld, H., 166 Dorofeeva, 0. V., 62 Dostal, K., 187, 260 Douglas, A. E., 272 Douglas, J . G., 78 Dousek, F. P., 110 Dovaston, N., 110 Dove, M. F. A., 294 232 Dowling, N., 289 Down, M. G., 2 Downey, J . R., 14, 40, 257 Dozzi, G., 90 Drager, M., 194, 222, 232, Drake, J. E., 134, 144, 145 Drakenberg, T., 289 Dreissen, W. L., 46 Drew, D., 44, 56 Drew, M. G. B., 45 Drobyazko, V. P., 104 Drullineer, L. F., 55 Dua, S. S., 148 Duax, W. L., 31 Dubler, E., 126 Dubovoi, P. G., 41 Duc, G., 45 Ducauze, C., 35 Ducourant, B., 228 Dudareva, A. G., 106, 267 Dudina, T. I., 101 Dudman, J., 87 Duffy, A. N., 234 Dugleux, P., 218 Dugua, J ., 273 Duke, B. J., 245 Dumas, J . L., 234 du Mont, W. W., 145, 162, 192, 195, 196 Duncan, R. H., 8, 92 Dunell, B. A., 73 Dung, N. H., 159, 258 Du Plessis, J. A. K., 208 Durana, J . F., 272 Durand, B., 218 Durand, J ., 216 Durand, M., 222 Durand, Ph., 119 Durham, M. J ., 109 Durif, A., 132, 165, 216 Durig, J. R., 76, 190, 192, 195 Durrant, J . A., 137 Duyckaerts, G., 7 D’yakov, V. M., 129 Dyatlova, N. M., 194 Dye, J. L., 24 Dyke, T. R., 285 Dymock, K., 102 Dzyubo, L. N., 15 Eaborn, C., 119, 148, 156 Eachus, R. S., 276 Eady, C. R., 94, 162 Ebbinghaus, G., 12 Ebert, L., 113, 295 Eberwein, B., 100, 214, 227 Ebner, J . R., 275 Ebsworth, E. A. V., 75, 119, 155,201 Eckert, J., 93 Edward, J . M., 155 Edwards, A. J., 136, 228, 229, 258 279, 280 Edwards, H. G. M., 234, 272 Edwards, J. O., 144,225,280 Edwards, P. A., 172, 226 Eeckhaut, Z., 151 Eengelke, C., 83 Egger, H., 7 Ehlert, K., 153 Eiletz, H., 210 Einstein, F. W. B., 201 Eisenmann, B., 37, 38, 220, Einstein, F. W. D., 155 Elegant, L., 76, 191 Eley, D. D., 39, 120 Elfwing, E., 107 El-Gad, U., 284 El Haj, B., 25 Elias, H., 276 Elieeva, N. A., 82 Eliseev, A. A., 258 Ellis, A. B., 291 Ellis, G. E., 9 Ellis, P. D., 72 El-Meligy, M. S., 254 Elter, G., 86 Elvard, A., 14, 257 Emel’Yanova, T. A., 262 Emme, L. M., 200 Emmenegger, F. P., 99 Emori, H., 120 Empsall, H. D., 57 Emri, J., 75 Emsley, J., 197, 275 Endell, R., 175, 178 Engelhardt, U., 203 England, W. B., 11, 117 Erb, A., 13, 216, 217 Erdos, E., 255 Eremin, Yu. G., 106 Eriks, K., 158 Ermler, W. C., 72 Ermolenko, N. F., 96, 217 Ertl, G., 247 EscudiC, J ., 145 Eshaque, M., 264 Esslin, W., 119 Etzrodt, G., 150 Eulenberger, G., 141 Evans, E. L., 112 Evans, M. L., 207 Evdokimov, V. I., 82, 251 Evenson, K. M., 114 Everstein, P. L. A., 46 Evlasheva, T. I., 178 Evsikov, V. V., 78 Ewert, W. B., 119 Ewings, P. F. R., 126, 161, Eysel, H. H., 14, 93 Ezhov, A. I., 103, 106, 185, Ezhov, V. K., 279 226 165, 166 186 Fabes, L., 255 302 Fabiani, C., 26 Fachinetti, G., 75 Falardeau, E. R., 197 Falconer, W. E., 294 Falius, H., 201 Faller, J . W., 153 Faniran. J. A., 47 Farmer, J . B., 44 Faucher, J. P., 206 Favre, R., 222 Fawcett, J ., 294 Feakins, D., 9 Fedetova, T. D., 288 Fedorenko, A. M., 107 Fedorov, P. I., 106 Fedorovich, I. S., 219 Fedoseev, D. V., 109 Fedot’ev, B. V., 145 Fedot’eva, I. B., 145 Feher, F., 119 Fehlner, T. P., 168 Fehrmann, R., 17, 264 Fehsenfeld, F. C., 117 Fenske, D., 195 Fernandez, V., 86 Fernandez-Prini, R., 10 Ferraris, G., 216 Feser, M., 200 Fes’kova, Zh. K., 267 Fessenden, R. W., 238, 253 Fiedler, R., 29 Field, R. J ., 235 Filippov, 0. A., 194 Filler, R., 294 Filowitz, M., 223 Finch, A., 192 Findlay, R. H., 86 Fink, D., 101 Fink, G., 90 Fink, H., 41 Fink, W., 152 Firer, R. L., 33 Fischer, E., 248 Fischer, G., 180 Fischer, J., 231 Fischer, J . C., 255 Fischer, P., 221 Fishwick, H., 81 Fitzer, E., 111 Flack, H. D., 221 Fleming, J. W., 256 Fletcher, I. S., 273 Fleury, G., 85 Flick, W., 200 Flora, H. B., 11 Flood, E., 77 Floriani, C., 75 Fluck, E., 77, 181, 189, 193, Flues, W., 248 Fodor, L., 178 Foffani, A., 153 Fogle, C. E., 272 Fokin, A. V., 183, 277 194, 212, 218, 219 Follner, H., 29 Folman, M., 15 Foo, W. B., 238 Foon, R., 271 Foord, A., 283 Ford, J ., 152 Ford, T. A., 174 Forel, M. T., 93 Forher, S., 162 Fornasini, M. L., 37, 89 Forst, D., 81 Fortune, P. J., 117 Forys, M., 256 Fotiev, A. A., 255 Fourcade, R., 228 Fowler, R. M., 98 Fox, W. B., 238, 278, 282 Franchetto, A., 8 Franchetto, R., 8 Frank, A., 175, 221 Franke, P., 123 Fraser, C. J . W., 293 Fredrickson, S. L., 119 Freeland, B. H., 105 Freund, R., 119 Freundlich, W., 216, 217 Friesen, D. K., 192 Frisch, M. J ., 54 Frit, B., 268 Fritz, G., 188, 196 Frlec, B., 292, 294 Frolov, Yu. A., 36 Fronczek, F. R., 70 Fruwert, J ., 241 Frydrych’, R., 134 Fryer, J. R., 33 Fujita, Y., 120 Fujiwara, T., 121 Full, R., 87 Fuller, H. J., 193 Funck, E., 79 Furuichi, R., 95, 284 Furukawa, Y., 266 Fuss, W., 83 Fusstetter, H., 85 Gabe, E. J ., 105, 233 Gabes, W., 280 Gabuda, S. P., 288 Gadzhieva, A. Z. , 262 Gaines, D. F., 43, 58 Gal, J . F., 76, 191 Galenko, E. V., 106, 267 Galignk, J . L., 216 Galinos, A. G., 103 Gallagher, M., 216 Galli, E., 95, 124 Galy, J ., 268 Gamarossa, F., 117 Gamba, A., 28, Gamble, R. H., 6, 103 Gamlen, P. H., 110 Gamsjager, H., 283 Ganchenko, E. N., 17 Author Index Ganelina, E. Sh., 268 Garber, A. R., 72 Gard, G. L., 200, 294 Gardner, G. L., 53 Gardner, I. R., 123 Gardner, P. J., 192 Gargano, M., 181 Garito, A. F., 244 Gamer, C. D., 131 Gamgon-Lagrange, C., 215 Gasperin, M., 78 Gasser, O., 193 Gates, B. C., 290 Gatineau, L., 110 Gaune-Escard, M., 18 Gautier, G., 237 Gavrilov, G. M., 82 Gauoni, G., 124 Geanangel, R. A., 76, 189 Gearhart, R. C., 98 Gehlert, P., 208 Geiseler, G., 241 Geller, S., 101 Gellings, P. J., 4 Gen’, L. I., 100 Gene, G., 216 Geneys, C., 159 Gennard, G. P., 158 Gennick, I., 13, 288 George, C., 114 George, T. A., 175 Gerardin, R., 37 Gergo, E., 125 Gerlach, R. F., 150 German, A., 266, 295 Gerwarth, U. W., 84 Geursen, G., 279 Ghemard, G., 269 Ghose, S., 79, 124 Gianelli, J . F., 113 Giannoccaro, P., 181 Gibb, T. C., 227 Gibson, J . A., 198, 294 Giese, R. F., 92 Giesen, K., 192 Gigukre, P. A., 285 Gilbert, A. S., 288 Gilbert, B., 95 Gilbert, R. A., 16 Gildewell, C., 203 Gilje, J . W., 199, 204 Gilkerson, W. R., 11 Gill, J. B., 252 Gillespie, H. M., 273 Gillespie, R. J ., 229, 246, 260, 283, 284, 289, 292, 293, 295 Gillman, H. D., 166 Gil‘man, L. M., 209 Gilmore, C. J., 97 Gilson, D. F. R., 32 Gingerich, K. A., 172 Ginley, D. S., 291 Ginzburg, A. G., 98 Author Index 303 Girgis, A. Y., 45 Giroux-Maraine, C., 23 1 Gitel’, P. O., 209 Giudice, M. T. L., 131 Given, R. M., 256 Glhsel, W., 201 Glasser, F. D., 72 Gleaves, J . T., 117 Gleitzer, C., 221 Glemser, O., 86, 200, 212, 231, 239, 242, 245, 246 Glick, M. D., 27, 91 Glidewell, G., 206 Glubokov, Yu. M., 98 Gobom, S., 171 Gode, G. K., 78 Godovikov, N. N., 62 Godzhaev, E. M., 104, 269 Goel, R. G., 134 Golin, M., 188 Gomory, P., 125 Gotz, J ., 122, 224 Goetze, R., 77, 84, 221 Gohel, V. B., 11 Gold, V., 236, 290 Goldberg, D. E., 169 Goldberg, I. B., 115, 136, 271, Goldman, A., 272 Goldsack, D. E., 8 Goldwhite, H., 191 Golic, L., 233 Golovanov, I. B., 175 Golub, A. M., 255 Golubinskaya, L. M., 99 Golubinskii, A. V., 99 Golubovskaya, 0. G., 9 Gombler, W., 239, 240 Gonar’, K. V., 96 Good, E. A. M., 234, 272 Goodall, D. C., 252 Goodrich-Haines, R., 204 Gopal, R., 10 Gordienko, V. I., 101 Goreaud, M., 124 Gorelov, I. P., 47 Gorgoraki, V. I., 77 Gosling, P. D., 191 Gould, R. O., 263 Goulet, P., 277 Graddon, D. P., 138 Grafe, E., 79 Gragg, B. R., 73, 84 Gragg, R. H., 87 Graham, B. W. L., 150 Graham, L., 294 Graham, W. A. G., 153, 154 Graham, W. R. M., 88 Grall, M., 1, Gramstad, T., 161 Grandjean, D., 142, 259 Grandjean, J ., 29 Granger, P., 293 Granier, W., 216 282 Grannec, J., 293, 295 Grant, J. L., 236, 290 Grantin, V. N., 238 Grapov, A. F., 203 Gray, I. D., 121 Greatrex, R., 142, 258 Grechkin, N. P., 220 Green, D. W., 177 Green, E. A., 31 Green, J . W., 241 Green, M., 67, 68, 70, 174 Green, T. H., 201, 270 Greenwood, N. N., 108, 142, 227, 258, 264 Gregory, A. R., 83 Gregory, N. W., 98 Grey, I. E., 101, 124 Griffin, A. M., 218 Griffiths, J . E., 187 Grigor’ev, A. N., 103 Grigor’eva, N. M., 267 Grigorovich, Z. I., 282 Grimes, R. N., 57, 65, 66, 68, Grinberg, J . K., 262 Grinko, V. A., 267 Grishchenko, V. F., 17 Grizik, A. A., 258 Grobe, J., 195, 200 Gromov, B. V., 285 Gropen, O., 77, 78, 80, 89 Grosse, J ., 197 Grosse-Bowing, W., 243 Groudin, J., 289 Grow, R. T., 13 Grube, G., 6, Gruter, H. F. M., 135 Grynkewich, G. W., 57 Guder, H. J., 105 Guerard, D., 113 Guerchais, J . E., 228 GuCrin, R., 188 Guest, M. F., 82 Guette, A., 36 GuiM, L., 278 Guillaume, M., 271 Guiller, A., 119 Guillevic, G., 55 Guillevic, J., 142, 259 Guisnet, M., 39 Guitel, J . C., 132, 216 Gunde, R., 289 Gundersen, G., 78 Gundorina, A. A., 91 Gupta, G., 99 Gupta, M. P., 31, 34 Gupta, S. K., 77 Gur’yanova, E. N., 93 Gusarov, A. V., 15, 273 Guseinova, B. B., 104, 269 Guseinova, Sh. M., 104, 269 Gusel’nikov, V. S., 268 Gut, R., 286 Gutcheck, R. A., 292 70 Guth, J . L., 95, 124 Guth, T. D., 174, 291 Guyader, J., 38, 220 Guyon, P. M., 284 Gynane, M. J., 136, 191 Gyori, B., 75 Gyunner, E. A., 107, 186 Ha, T. K., 72 Haaland, A., 56 Haas, A., 74, 80, 259 Haase, W., 267, 289 Habeeb, J . J ., 104, 105 Haber, J ., 252 Haber, K., 177 Habibi, N., 228 Hadenfeldt, C., 53, 188,221 Hadzi, D., 289 Haberlein, M., 74, 80 Haeberlen, U., 288 Hadicke, E., 219 Haegele, R., 97 Hausler, K. G., 144 Hagen, A. P., 238 Hagen, K., 193 Hagenmuller, P., 36, 177,295 Hagiwara, S., 112 Haigh, M., 116 Halgren, T. A., 54 Hall, P. G., 40 Hall, S. M., 97 Halstead, G. W., 70 Halstenberg, M., 200, 250 Hamada, S., 248 Hameed, A., 192 Hamelin, M., 52 Hamid Bin Othman, A., 45 Hammer, R., 125, 175 Hamon, M., 38, 220 Hamza, A., 245 Hand, C. W., 114 Handrich, M., 283 Hanic, F., 78 Hansen, D. A., 114 Hansen, L. D., 21 Hanzel, D., 295 Haran, G., 60 Hargittai, I., 99, 125, 158 Hargittai, M., 99 Hargreave, M. M., 254 Harkema, S., 46 Harmon, K. M., 13, 288 Harris, D. H., 169, 171 Harris, R. K., 205, 206 Harris, S. J ., 292 Harris, W. R., 100 Harrison, B. H., 112 Harrison, P. G., 121, 122, 125, 126, 133, 143, 161, 163, 165, 166, 168, 169 Harrison, W. D., 252 Haruta, M., 285 Harrod, J . F., 157 Hartl, H., 134, 203 304 Author Index Hartman, J . S., 72, 81 Haschke, J . M., 197 Hasegawa, Y., 217 Haser, R., 253 Hass, D., 223 Hassan, L. A. R., 39 Hathaway, K. B., 14 Hattori, H., 39, 290 Hau, H. H. K., 158 Haubold, W., 74, 82, 212, 218 Haupt, H. J ., 154, 160, 261 Hausen, H. D., 105, 230 Haussuhl, S., 288 Havel, J . J., 114 Hawthorne, M. F., 66, 68, 69, Hawthorne, W. F., 58 Hayashi, J ., 110 Hayashi, M., 135 Hayding, R. D., 262 Hayek, E., 217 Haynes, D. M., 171 Hayter, A. C., 152 Hazell, R. G., 123 Head, R. A., 175 Heckmann, G., 77, 189, 193 Hedberg, K., 193 Hedberg, L., 193 Hedwig, G. R., 10 Heeger, A. J., 244 Heicklen, J ., 114, 177, 236, Heidemane, G., 173 Heinicke, J., 221 Heinrich, S., 221 Heinsen, H. H., 280 Held, J ., 145 Hellwinkel, D., 215 Hemmings, R. T., 134, 144, Hemsworth, R. S., 117 Hencher, J . L., 105, 117, 134 Henderson, E., 145 Hengel, R., 133 Hengge, E., 146 Henry, R., 219 Herberich, G. E., 83 Herbertsson, H., 28 Herman, R. G., 217 HehBnek, S., 61, 63 Herold, A., 113 Hertz, R. K., 55 Herzog, J . F., 228 Hess, H., 81, 87 Hesse, R., 107, 126 Heumann, K. G., 275 Heyder, F., 262 Heymann, M., 195 Heyrovsky, M., 235 Hickey, J . P., 63 Hidai, M., 174, 175 Hierl, P. M., 114 Hierl, R., 88 Higashihara, T., 256 70, 71, 252, 273 145 Higginson, W. C. E., 171 Hildebrant, S. J., 43, 58 Hill, R. M., 292 Hillel, R., 222, 262 Hillenrotter, B., 6, 12 Hillier, I. H., 226 Hilty, T. K., 65 Hinton, J . F., 106 Hirabayashi, K., 157 Histatsune, I. C., 177, 252 Hitchcock, P. B., 175 Hjersing, H., 221 Hjortas, J . A., 49 Hochenbleicher, J . G., 273 Hockey, J . A., 121 Hodgson, P. G., 253 Hoebbel, D., 122, 123 Holler, F., 135 Hogel, J ., 210 Hoel, E. L., 71 Hoenig, C. L., 36 Horkner, W., 95 Hofer, R., 200, 239 Hoffman, P. R., 190, 275 Hogg, J . H. C., 104, 268, 269 Hohaus, E., 87 Hoheisel, C., 57 Hohorst, F. A., 182 Holah, D. G., 56, 57 Holcombe, C. E., 88 Holderich, W., 188, 196 Holland, R. F., 238 Holliday, A. K., 169 Holloway, B. E., 21 Holloway, J . H., 292, 293,294 Holm, J. L., 16 Holmes, R. R., 215 Holton, J., 90 Holtschneider G., 241, 245 Honda, H., 227 Hong, K. C., 16 Honnick, W. D., 139, 162 Hoodless, I. M., 39 Hoppe, R., 41 Hooley, J . G., 113 Hooper, A. J., 4, 5 Hopkins, H. P., 28 Hopkinson, M. J ., 191 Hoppe, R., 97, 101, 104 Horibe, Y., 217 Horn, F., 219 Horstschafer, H. J., 60 Hoshino, Y., 184 Hough, E., 159 Hovland, A. K., 27 Howard, B. J ., 285 Howard, C. J ., 114 Howard, J . A., 108 Howard, J . A. K., 68, 97 Howarth, 0. W., 93 Hoyte, 0. P. A., 275 Hsu, Y. F., 199 Hubbard, W. N., 13, 281 Hubberstey, P., 2, 5 Hubble, B. R., 18 Huber, F., 106, 129, 131, 149, Huber, H., 174 Hubner, H. J., 261 Hucke, E. E., 116 Huczko, A., 176 Hudgens, J . W., 117 Hudgins, R. R., 251 Hudson, A., 191 Hubner, H. J., 102 Huestis, D. L., 292 Huettner, W., 277 Huffman, J. C., 55, 61, 63, 85 Hughes, A. N., 56, 57 Hughes, B., 131 Hughes, D. L., 22 Hughes, M. C., 139 Hughes, M. N., 179 Hui, B. C., 56, 57 Hui, K. K., 116 Hulme, R., 228 Hunt, C. J., 114 Hunter, R. A., 217 Hunter, W. E., 90 Huntress, W. T., 115 Hursthouse, M. B., 207 Husain, D., 273 Husband, J . P. N., 87 Huttner, G., 175, 221 Hutton, R. E., 136, 143 Huvenne, J . P., 280 Huy, T. B., 283 160, 261 Idler, K. L., 217 Ido, T., 271 Idriss, K. A., 254 Ihle, H., 39 Ihle, H. R., 4 Iitaka, Y., 26 Lizuka, T., 39 Ikrami, D. D., 288 Il’icheva, L. M., 93 Il’inskaya, G. P., 285 Il’yasov, I. I., 18 Imai, H., 111 Innorta, G.. 153 Inoue, H., 176 Insinga, R., 11 1 Inyushkina, T. L., 15 Ireland, P. R., 246, 263 Irene, E. A., 141, 262 Irish, D. E., 46 Isaeva, S. A., 173 Ishii, T., 95 Ishimori, T., 157 Ishley, J . N., 199 Ismanov, E., 255 Issa, I. M., 254 Issa, R. M., 35 Issleib, K., 193, 227 Ito, O., 251 Ivanov, V. A., 119 Author Index 305 Ivanov-Emin, B. N., 103, 185, Ivanouskii, L. E., 15 Ivashina, G. A., 8 Ivashkovich, E. M., 179 Ivchenko, N. P., 78 Ivchenko, V. I., 177 Iwamoto, M., 271 Iwatani, K., 86 Iyer, R. S., 271 Izatt, R. M., 21 186 J ablonka, B., 223 J ache, A. W., 286 J ackson, D., 30 J ackson, J . A., 192 J acob, E., 283, 284, 295 J acobs, H., 53 J acobson, H. J ., 142 J acobson, R., 146 J acobson, R. A., 229 J agur-Grodzinski, J ., 25 J ahn, C., 107 J alenti, R., 8 J ames, B. D., 56 ' J ames, V. J ., 29 J ameson, G. B., 46 J amieson, P. B., 122 J anda, K. C., 292 J andacek, R. J ., 215 J ander, J ., 188, 279 J anghoroani, M., 47 J annach, R., 135 J ansen, M., 183 J ansen, P. R., 150 J ansen, W., 177 J anssen, E., 211 J ansta, J ., 110 J anz, G. J ., 14, 40, 257 J anzen, A. F., 198, 294 J apar, S. M., 114, 235 J asinski, R., 291 J ayanty, R. K. M., 273 J efferies, A. T., 88 J efferson, D. A., 95, 124 J effes, J . H. E., 281 J effries, J . B., 101 J eminet, G., 30 J enkins, H. D. B., 98, 136, J ennings, H. M., 144 J ennings, V. J ., 178 J ennische, P., 107 J enny, S. N., 97 J ensen, H. H., 78 J ensen, W., 146 J epson, B. E., 35 J esse, A. C., 175 J ha, M. C., 7 J ha, N. K., 229 J ohansen, R., 80 J ohansson, A., 286 J ohansson, G. B., 96,213,268 J ohnson, B. V., 153 264 J ohnson, D. H., 88 J ohnson, G. K., 13 J ohnstone, F. J ., 254 J olivet, J . P., 231, 232 J olly, W. L., 179, 234, 281 J onas, A., 129 J on& I., 94 J onas, K., 175 J ones, C. L., 263 J ones, P., 266 J ones, R. G., 9 J ones, T. R. B., 73, 193 J ones, W. E., 271 J ordan, T. H., 165 J drgensen, C. K., 285 J ouany, C., 76, 191 J owko, A., 256 J uhach, T., 209 J ugie, G., 76, 191, 222 J uhola, A. J ., 112 J uillard, J ., 30 J umas, J . C., 266 J ung, C. W., 69 J ung, W., 89 J urado, B., 94 J urek, R., 277 J urkschat, K., 129 J utzi, P., 82, 162 Kabachnik, M. I., 62, 194 Kabre, T. S., 257 Kadoshnikova, N. V., 104,260 Kahl, S. B., 63 Kajiwara, M., 209 Kakimoto, N., 125 Kakli, M. A., 194 Kalarova, M., 282 Kalasinsky, V. F., 76, 190 Kalayannis, N. M., 214 Kal'chenko, V. I., 199 Kalinina, G. S., 146 Kalinnikov, V. T., 262 Kalker, H. G., 248 Kaluzene, S., 209 Kalyanaraman, B., 288 Kamenek, L. K., 41 Kaminaris, D., 103 Kamiya, K., 110 Kamiyama, Y., 152 Kampel, V. Ts., 62 Kampfmeyer, G. L., 93 Kanaeva, 0. A., 59 Kanungo, S. B., 39 Kapoor, P., 241 Kapoor, R., 27, 241 Kapralova, G. A., 272 Kapustnikov, A. I., 47 Karasawa, T., 271 Karataeva, I. M., 8 Karelin, A. I., 282 Kartzmark, E. M., 105, 106 Kashireninov, 0. E., 38 Kasimov, G. G., 95 Kastner, P., 41 Kato, K., 39 Kato, M., 254 Katsu, T., 120 Katty, A., 142, 269 Kaufman, F., 117 Kaufman, M., 271 Kaufmann, J ., 224 Kaurova, G. I., 285, Kaus, M. J ., 225, 280 Kawada, I., 39 Kawahara, A., 123 Kawai, T., 235 Kawamura, K., 123 Kawanisi, M., 148 Kawano, M., 248 Kawano, Y., 270 Kazantsev, G. N., 16 Kazenwadel, W., 194 Keable, J ., 144 Keat, R., 201, 205, 211, 270 Keii, T., 121 Kelly, B., 14, 257 Kelly, H. C., 73 Kelmer, A. D., 18 Kemball, C., 39 Kemme, A. A., 129 Kempny, H. P., 188 Kennard, C. H. L., 253 Kennedy, J . D., 149 Kereichuk, A. S., 93 Kern, C. W., 72 Kern, R. D., 117 Keropyan, V. V., 255 Kerridge, D. H., 18, 19, 186 Kessel, H., 177 Ketalaar, J . A. A., 14 Keuhn, D. G., 182 Khaitova, M., 288 Khalafalla, E. S., 182 Kharitonov, Yu. Ya., 104, 260 Khidekel, L. M., 173 Khodadadeh, K., 172 Khodashova, T. S., 157 Khotsyanova, T. L., 103 Khudhan, A. Y., 19 Khudolozhkin, V. N., 16 Kidd, D. R., 151 Kiefer, W., 273 Kilgour, J . A., 146 Kim, K. S., 79 Kim, P. H., 111 Kim, S. Y., 8 Kimura, T., 157 Kinberger, K., 169 Kindsvater, J . H., 57, 62 King, R. W., 73 King, S. C., 14 King, T. J ., 125, 126, 131, 165, 166 King, W. T., 237 Kipnis, I. S., 215 Kirchmeier, R. L., 242 Kireeva, A. Ya., 194 Kiremire, E. M. R., 175 306 Author Index Kirsch, P. P., 291 Kispert, L. D., 288 Kitazima, S., 227 Kiwanuka, G. M., 39, 120 Kizilyalli, M., 216 Kjekshus, A., 221, 232 Klaasen, A. A. K., 21 Klar, G., 266 Klar, W., 107 Klei, E., 212, 213 Klein, H. F., 175 Kleinschmager, H., 14 Klemperer, E. W. G., 223 Klemperer, W., 285, 292 Kleppa, 0. J ., 16 Kleppinger, J ., 244 Klevtsov, P. V., 95 Klimchuk, G. S., 59 Klingebiel, U., 212 Klingen, T. J ., 62, 63 Kloth, B., 189, 218 Klotzbuecher, W., 174 Kluger, R., 45 Klushmann, E. B., 60 Knachel, H. C., 199 Knackmuss, J ., 188 Knapczyk, J., 183 Kniep, R., 264 Knips, V., 106 Knoche, H., 256 Knochel, A., 266 Knoll, F., 116, 192 Knuth, K., 279 Knyazev, S. P., 62 Kobayashi, A,, 124 Kobayashi, H., 39 Kobayashi, K., 148 Kober, F., 223, 224 Kober, V. I., 6 Kobycheva, S. A., 255 Koch, B., 259 Koch, D., 189, 218 Koch, W., 83 Kochergin, V. P., 135, 161 Kocheskov, K. A., 135 Kodaira, K., 122 Kodarna, G., 74 Kodejs, Z., 171 Kodina, G. E., 100 Kohler, H., 204, 205 Koenig, M., 216 Koepke, J . W., 281 Koerner von Gustorf, E. A., Kiister, R., 60 Kohatsu, I., 142 Koizumi, H., 216 Kolarov, N., 282 Kolb, C. E., 272 Koldashov, N. D., 101 Kolli, I. D., 95 Kollman, P., 286 Kolobova, N. E., 98, 137 Kolonits, M., 158 94 Kolsi, A. W., 216, 217 Kolyshev, A. N., 101 Komarek, K. L., 125 Komeya, K., 176 Komissarova, L. N., 103 Kondow, T., 235 Konno, M., 31 Konov, A. V., 267 Konovalov, L. V., 156 Konrad, P., 99 Kopp, H. P., 259 Kopylov, N. I., 226, 257 Kornilova, V. T., 15 Korobov, 1. I., 91, 178 Korol’, E. L., 194 Korol’ko, V. V., 62 Korovin, S. S., 98 Korovina, V. G., 8 Korshak, V. V., 209 Korshunov, B. G., 15, 267 Korshunov, I. A., 16, 18 Koshkin, V. M., 275 Kosiol, W., 188 Kosolapova, T. Ya., 177 Kostiner, E., 216 Koto, K., 123 Kotov, A. G., 180 Koubowetz, F., 39 Kouinis, J ., 103 Kovacevic, S., 218 Kovaleva, I. S., 257, 269 Kovba, L. M., 255 Kozachenko, E. G., 267 Kozachenko, E. L., 255 Kozak, J . J ., 8, Kozhina, I. I., 108, 269 Kozima, S., 148 Kozlovskii, E. V., 96, 285 Kozuka, S., 119 Kraatz, U., 74 Krannich, H. J., 242, 243 Krapp, W., 215 Krasnenkova, L. V., 255 Krasznai, J . P., 284 Krause, J . R., 118 Krauzoldt, N. P., 95 Kravchenko, 0. V., 55, 91, 178 Krebs, B., 141, 142, 166, 207, 245, 258, 266 Kreiter, C. G., 90 Kreiter, R. L., 155 Kress, J . W., 8, Krisher, L. C., 134 Krishnamurthy, S. S., 208,211 Krivtsov, N. V., 184 Kriz, J . F., 121 Kriz, P., 11, Krokhin, V. A., 15 Krol, H., 95 Kroner, J., 72, 83 Kroshefsky, R. D., 204 Kroth, H. J ., 145, 162, 195 Kroto, H. W.. 82. 191 Kruchenko, V. P., 253 Kruck, T., 153 Krudenko, V. P., 255 Kriiger, C., 74, 87 Kruger, G. J ., 51, 104 Kruglya, 0. A., 145 Krumhansl, J . A., 14 Krylov, E. I., 180 Kryukova, A. I., 16, 18 Ksenzenko, V. I., 267 Kubisen, S. J ., jun., 215 Kubota, M., 182 Kudinova, A. A., 96,267, 268 Kudo, Y., 248 Kudyakov, V. Ya., 16 Kuehn, C. G., 256 Kulps, H. J ., 86 Kugel, R. L., 207 Kuhn, A., 102 Kuhn, A. T., 271 Kuhn, L. P., 235 Kuimova, M. E., 83 Kukushin, Yu. N., 156 Kul’ba, F. Ya., 100, 103, 106 Kullman, H. J., 6, Kumaria, J. N., 47 Kummer, D., 172 Kunicki, A., 94 Kunimori, K., 235 Kuntz, I. D., 11 Kunz, R. G., 113 Kunze, U., 133 Kura, G., 218 Kuratova, T. S., 8 Kurin, N. P., 185 Kurkutova, E. N., 78 Kuropatova, A. A., 106 Kutoglu, A., 225, 258 Kutty, T. R. N., 131 Kutzelnigg, W., 57 Kuvakina, L. M., 18 Kuwashima, S., 251 Kuzina, T. V., 267 Kuzmicheva, V. P., 268 Kuznetsov, E. V., 164 Kuznetson, N. T., 59 Kutnetsov, V. A., 38 Kuznetsova, A. A., 214 Kuznetsova, G. P., 255 Kuznetsova, L. D., 183, 277 Kuznetsova, S. T., 104 Kwak, W., 217 Kyrs, M., 1 Labarre, J . F., 206 Ladd, M. F. C., 107 Laffitte, M., 36 Lafontaine, J ., 113 Lagaly, G., 217 Lagow, R. A., 28 Lagow, R. J., 272 Lahiri, S. K., 125 Laing. K. R., 175 Laitinen, R., 247 Author Index 307 Lakovits, J . M., 73 Lalancette, B. D., 115 Lalancette, J . M., 113 Lam, S. Y., 289 Lambert, L., 72 Lampe, F. W., 118 Lance, E. T., 197 Landa, B., 278, 293, 295 Lang, J ., 37, 100, 188, 220 Lang, M., 219 Lange, U., 205 Langenscheidt, E., 39 Langer, E., 195 Langler, R. L., 242 Langsam, Y., 273 Lapkin, I. I., 74 Lappert, M. F., 82, 90, 136, 169, 170, 171, 191 Larichev, N. N., 115 Larvelle, P., 142, 269 Lassmann, E., 238 Laszlo, P., 29 Latscha, H. P., 230 Latypov, Z. M., 262 Latzel, J ., 39 Lau, C., 259, 264, 277 Lau, K. K., 60, 61 Lauchlin, W. C., 98 Laurent, J . P., 92, 222 Laurent, Y., 100, 220 Laussac, J . P., 92 Lavrey, A. H., 114 Lazarini, F., 233 Lazzard, C. P., 115 Leach, J . B., 54 Leary, K., 281 Lebedeva, A. S., 209 Lebedeva, V. I., 62 Leblanc, R. B., 129 Leclerc, B., 257 Le Cloarec, M. F., 218 Lecompte, C., 125 Ledesert, M., 51 Lee, D. A., 35 Lee, F. W., 116 Lee, L. S. M., 120 Lee, Y. T., 272, 276 Leeb, R., 258, 262 LefBbvre, J., 231, 232 Legasov, V. A., 182 Legrand, P., 280 Legrange, J . D., 271 Lehmann, E., 280 Lehn, J . M., 25 Leigh, G. J ., 174, 175 Leipunskii, I. O., 115 Leitloff, M., 218 Lemanski, M. F., 146, 156 Lemberton, J . L., 39 Lemerle, J., 232 Lemmon, D. H., 192 Lenglet, M., 101 Lenkinski, R. E., 49 Lerbscher, J . A., 136 Lerf, A., 16 Leroy, G., 286 Leroy, M. J . F., 230 Lesiecki, M. L., 107 Lesnaya, M. I., 177 Lestrat, H., 142, 259 Letoffe, J . M., 14, 257 Leubner, R. L., 175 Levin, G., 19, 21 Levin, I. W., 198 Levin, V. I., 100 Levina, N. A., 267 Levshin, V. A., 269 Levy, R., 178 LCvy-CICment, C., 232 Lew, L., 60 Lewis, E. S., 119 Leyden, R. N., 58 L'Haridon, P., 38, 100, 220 Li, N. C., 93 Li, Y. S., 195 Licheri, G., 8 Lichtenberger, D. L., 151 Liebhafsky, H. A., 284 Liebman, J . F., 293 Liegeois-Duyckaerts, M., 184, Lilenfeld, H. V., 257 Lin, C. H., 113, 295 Lin, H. C., 229, 241 Lin, M. C., 115, 116 Lin, M. J ., 39, 251 Linderberg, J., 282 Lindlinger, W., 117 Lindgy, S., 80 Lindquist, O., 96, 213, 268 Linke, D., 262 Linke, K. H., 203, 248 Linnett, J . W., 11 Linz, A., 291 Lippert, E., 255 Lipscomb, W. N., 54 Liskow, D. G., 293 Little, J . L., 64 Littlefield, L. B., 199 Litvinov, Yu. G., 18 Litvinova, G. N., 41 Lityagov, V. Ya., 267 Liu, B., 293 Liu, S. T., 53 Live, D., 24 Liyagov, V. Ya., 106 Lloyd, D. J., 101, 124 Lloyd, J . P., 175 Lobkov, E. V., 41, 238 Loeffler, P. A., 151 Liifving, I., 160 Loehr, T. M., 294 Loew, L. M., 214 Lofiedo, R. E., 55 Lofthouse, M. G., 39 Lokshin, B. V., 98, 137 Long, D. A., 234, 272 Long, G. G., 228 268 Long, J . R., 55 Longato, B., 70 Longuemard, J . P., 256 Lopitaux, J ., 101 Lorents, D. C., 292 Lotterhos, H. F., 276 Louis, C., 289 Louis, E. J ., 244 Louteman-Leloup,G., 18,286 Lovering, D. G., 18, Loveskaya, G. A., 255 Low, H. S., 237 Loyola, V. M., 26 Lucchese, R. R., 177 Luger, P., 250 Luk, W., 263 Lundehn, J.-R., 238 Lunderen, B., 19 Lundgren, J . O., 289 Lunsford, J . H., 39, 175, 182, Lustig, M., 213 Lutar, K., 282, 295 Lutz, H. D., 253 Luzhnaya, N. P., 269 Lyapilina, M. G., 180 Lyapina, T. G., 180 Lynch, D. A., 77 Lynch, R. J ., 199 Lysenko, Yu. A., 106 Lysy. R., 7 Lyubimov, V. N., 238 Lyudomirskaya, A. P., 255 Lyutsko, V. A., 96, 217 Lyzlov, Yu. N., 98 McArnish, L. H., 254 McClelland, B. W., 94 McClure, N., 64 McCusker, M. V., 292 MacDiarmid, A. G., 244 McDonald, J . D., 117, 272 McDonald, R. C., 158 McDowall, J . M., 9 McDowell, R. S., 238 McEnaney, B., 110 McFadden, D. L., 275 McFall, S. G., 45 McFarlane, H. C. E., 145 McFarlane, W., 73, 145, 149 Machado, G., 114 Maciel, G. E., 8 Mackay, K. M., 150 McKee, D. W., 112 McKelvey, J ., 286 McKennon, D. W., 213 Mackenzie, R. E., 174 Macleod, A. C., 16 McPhail, A. T., 99 McRae, V. M., 293 McReynolds, J . H., 184 McVicker, G. B., 49 McWhinnie, W. R., 270 Madan, H., 230 25 1 Author Index Madeira, S. L., 288 Maddock, A. G., 263 Maeda, K., 109 Maeda, M., 8 Markl, G., 221 Magnotta, V. L., 290 Magunov, R. L., 262 Mahata, A. P., 34 Maheshwari, S. C., 120 Mahgoub, A. E., 102 Mahnvald, R., 107 Maier, M., 82 Maillard, D., 251 Maillot, F., 55 Mainwood, A,, 3 Maiorova, E. A, , 7 Maiorova, L. P., 156 Mairesse, G., 98, 105 Makarov, S. V., 285 Makarov, Yu. V., 137 Makhija, R., 161 Makide, Y., 271 Makihara, M., 209 Makin, P. H., 169 Makotchenko, V. G., 294 Maksyukova, E. V., 92 Malhotra, K. C., 79, 80, 229, Malik, W. U., 120 Malinowski, E. R., 10 Malisch, W., 229 Malkova, A. I., 282 Mallon, T., 224 Maloney, K. M., 77 Malova, N. S., 106 Maltsev, A. K., 158 Mal’tsev, V. T., 79 Mal’tseva, N. N., 56 Mal’tseva, V. S., 106 Malysa, K., 252 Malysheva, E. S., 267 Marnantov, G., 95 Mandt, J ., 141 Manelis, G. B., 38 Mangia, A., 126 Mangion, M., 48, 55, 58 Mangria, A., 143 Mannan, Kh. M., 29,208,211 Manning, K., 48 Manning, R. G., 115 Manohar, H., 208 Manoussakis, G., 143 Marat, R. K., 198, 294 Marchand, A., 285 Marchand, R., 100, 101, 177, Marchenko, A. P., 204 Marcotrigiano, G., 229 Mardakhaev, B. N., 262 Mardirosova, I. V., 217 Marecek, J . F., 215 Marenkova, I. N., 15 Marezio, M., 79 Markila, P. L., 29 255, 280 220 Markov, V. S., 253 Marks, T. J ., 57 Maroni, V. A., 173 Marsh, H., 109 Marsden, C., 266 Marshall, K., 121 Marshall, W. L.,’ 255 Marsmann, H. C., 241 Martell, A. E., 100 Martens, H. F., 135 Martin, D., 278, 282 Martin, D. R., 74, 270 Martin, G. D., 39 Martin, R. L., 284 Martinos, N., 9 Martinot, L., 7 Martin-Rodriguez, A., 112 Martynyuk, A. P., 202, 204 Marynick, D., 54, 56 Masai, M., 121 Masaki, M., 161 Mascherpa, G., 228, 286 Mascherpa-Corral, D., 102, Masood-ul-Hasan, 207 Mastryukov, V. S., 62, 99 Matcha, R. L., 14 Matchuk, N. M., 282 Materova, E. A., 232 Matheson, A. J., 9 Mathiasch, B., 147 Mathur, M. A., 63, 73 Matsuda, M., 251 Matsui, S., 285 Matsui, Y., 31 Matsumoto, K. Y., 124, 254 Matsumura, C., 116 Matsumura, Y., 112 Matsunarni, S., 161 Matsushita, T., 122 Matsuura, N., 25 Matsuzaki, A., 257 Mattes, R., 36, 118 Matteson, D. S., 78 Matthews, G. P., 234 Matthews, J . J ., 157 Mattschei, P. K., 60 Matzek, N. E., 89 Maunaye, M., 100, 220 Maurel, R., 39 Maurer, A., 279 Mauridis, A., 144 Maurin, M., 266 Maxwell, W. M., 66, 70 Maya, L., 79 Maybury, P. C., 89 Mazid, M. A., 49 Mazieres, J ., 232 Mazitov, R. K., 8 Mazzei, A., 90 Meadows, J . H., 157 Meagher, J . F., 114 Medved, I. Ya., 194 Meehan, B. J ., 18, 186 103 Meek, D. W., 193 Mehra, S., 97 Mei, E., 24 Meider-Gorican, M., 22 Mein, J ., 113 Melford, S. S., 98 Meller, A., 212 Mellini, M., 75 Mel’nichenko, L. M., 186 Mel’nikov, N. N., 203 Menabue, L., 229 Menchetti, S., 79 Meneghelli, B. J ., 64 Menge, G., 37, 188 Menge, R., 261 Menke, H., 227 Mentzen, B. F:, 262 Mentzer, E., 57 Mercier, R., 223 Menaudeau, P., 235 Merlino, S., 75 Merlo, F., 37, 89 Merrin, S., 79 Merryman, D. J., 226 Meschede, W., 118 Metcalf, A. S., 18 Metcalf-J ohansen, J ., 123 Metzger, R. M., 62 Meunier, G., 261, 268 Meunier, J., 93 Mews, R., 242 Meyers, E., 83 Meyers, E. A., 48, 58 Mezentseva, L. P., 216 Michaud, M., 14 Michaylova, V., 92 Michel, A., 232 Michel, W., 116, 192 Michelbrink, R., 279 Michielsen, J ., 14 Middlemiss, N., 218 Middleton, T. B.,. 197 Mijlhoff, F. C., 125 Mikaelian, R. G., 158 Mikhailov, B. M., 83, 85 Mikhailova, M. I., 285 Mikhailova, 0. B., 203 Mikhailyuk, Yu. I., 101 Mikheeva, L. M., 103 Mikheeva, V. I., 56 Miki, E., 157 Mikolajczyk, M., 218 Mikulski, C. M., 214, 244 Milbrath, D. S., 214 Miles, S. J ., 170 Miller, A., 166 Miller, F., 172 Miller, F. A., 82 Miller, J . M., 73, 193, 275 Miller, L. L., 279 Miller, N. E., 76 Miller, R. W., 99 Miller, S. B., 70 Miller, V. H., 54 Author Index 309 Miller, V. R., 57, 66 Mills, A. K., 121 Mills, B. E., 284 Mills, J . A., 29 Mills, J . L., 189, 213 Milne, J . B., 284 Mil’ner, A. P., 275 Milstein, R., 271 Min, T. B., 215 Minh, N. Q., 17 Minkevich, S. M., 226, 257 Mironov, V. F., 135, 161 Mironov, V. L., 16 Mironov, V. S., 15 Mironova, A. S., 101 Mirsoyanova, N. N., 41 Mishin, V. Ya., 268 Mitchell, R. W., 89 Mitkin, V. N., 238, 294 Mitra, S., 51 Mizoguchi, T., 254 Mizumachi, K., 157 Mocek, K.. 255 Mochida, I., 109 Moedritzer, K., 220 Moffett, D. M., 284 Mohammad, M., 19 Mohmad, S., 251 Mohriari, E., 117 Moiseeva, 0. A., 194 Molls, W., 153 Molodkin, A. K., 106, 267 Momot, 0. A., 185, 186 Mongeot, H., 55, 82 Monnaye, B., 124 Monteil, Y., 218, 220, 247, Montenarh, M., 203,243,246, Montero, S., 253 Moody, D. C., 55 Mooij, J . J ., 21 Moore, F. H., 253 Moore, G. Y., 206, 207 Moore, P., 93 Moorse, S. D., 242 Mootz, D., 210, 264 Morachevskii, A. G., 7 Morandini, F., 70 Morbach, W., 116, 192 Moreland, C. G., 199 Morgan, G. L., 44, 56 Mori, K., 121 Morimoto, N., 123 Moroni, V. A., 2 Morosi, G., 28 Moroz, N. K., 288 Morozov, A. I., 92 Morozov, I. I., 115 Morris, A., 165 Morris, C. W., 4 Morris, J . H., 43, 58 Morris, K. P., 236, 290 Momson, J . A., 28, 134 258, 262 252 Morrow, B. A., 120 Morse, D. L., 291 Morse, K. W., 76, 190 Mom, L. R., 15 Morton, J . R., 277 Moshinskii, A. S., 255 Motegi, S., 31 Motov, D. L., 255 Motte, J . P., 176 Mozaffar-Zanganeh, H., 218 Muckle, G., 88 Mudd, K. R., 138 Muller, A., 141 Muller, H., 145 Muller, J ., 204 Muller, K. D., 84 Muller, U., 230 Miiller-Buschbaum, H., 95,96 Mulcahy, M. F. R., 111 Mulder, N., 111 Mullen, D. J . E., 228 Muller, W., 269 Multani, R. K., 97 Munoz, A., 216 Muraishi, K., 47 Muramoto, H., 121 Murata, H., 33, 135 Murav’ev, I. V., 219 Murcray, D. G., 272 Murcray, F. H., 272 Murdoch, J. D., 145 Murphy, H. S. G., 131 Murray, R. M., 262 Murthy, A. R., 211 Musaev, D. B., 180 Mustoe, F. M., 134 Muxart, R., 218 Muylle, E., 77 Myers, R. M., 114 Myers, W. H., 73 Mysin, N. I., 148 Nabi, S. N., 208 Nabiev, M. N., 185 Nacken, B., 6 Nadler, H. G., 227 Nae, N., 25 Nagakura, S., 257 Nagasawa, A., 126 Nagase, K., 47 Nagel, B., 241 Nahigian, H., 219 Nakadaira, Y., 152 Nakai, Y., 46 Nakajima, T., 15 Nakajima, Y., 122 Nakamoto, K., 161, 173 Nakamura, E. I., 109 Nakanishi, K., 15, 286 Namba, S., 111 Namura, S., 111 Nancollas, G. H., 53 Nanda, R. K., 94 Nardelli, M., 131 Narein, G., 260 Narita, H., 123 Naslain, R., 36 Naumann, D., 280 Nawata, Y., 26 Nazarov, A. S., 277, 294 Nefedov, 0. M., 158 Negita, H., 266 Negoiu, D., 175 Neidhard, H., 36 Nekrasov, V. N., 15 Nelson, G. V., 19 Nelson, J . F., 134 Nelson, R. W., 59 Nelson, S. M., 45 Nelson, W. H., 129 Nemchenko, V. F., 177 Neudert, B., 162, 192 Neuman, W. P., 145 Newkirk, D. D., 243 Ng, C. H., 93 Ng, Y. S., 46 Nibler, J. W., 43, 44, 56, 107 Nichkov, I. F., 6 Nicholas, G., 119 Nicholls, C. J ., 38 Nicholson, D. G., 159, 232 Nickels, K. O., 177 Niecke, E., 200 Niedenzu, K., 86 Nielsen, S. F., 21 Nielsen, U., 293 Niinisto, L., 247 Niki, H., 114, 235 Nikolaev, A. V., 294 Nikolaev, N. S., 272 Nikovaev, V. M., 181 Nikolaeva, A. D., 183, 277 Nikol’skii, B. A., 79 Nikol’skii, V. M., 47 Nikonenko, E. A., 180 Nikonorov, Yu. I., 294 Nikonorova, L. K., 220 Nikonova, L. A., 173 Nikulenko, V. S., 267 Nilssen, E. W., 89 Nip, W. S., 235 Nisel’son, L. A., 98 Nishida, H., 35 Nishida, T., 35 Nishikida, K., 191 Nishiyama, Y., 110 Nitsche, R., 104 Nixon, E. R., 244 Nixon, J . F., 191 Nobile, C. F., 175 Noda, M., 112 Noe, E. A., 29, 30 Nolle, D., 83 Noth, H., 72, 73, 75, 76, 77, 81, 83, 84, 85, 88, 89, 90, 99, 202, 221 Noftle, R. E., 241 Noller, H., 39 310 Author Index Noltes, J . G., 140, 141, 148 Noordik, J . H., 21 Nord, A. G., 253 Nordkn, B., 94 Nordine, P. C., 271 Norman, A. B., 28 Norman, A. D., 55, 196 North, P. P., 51 Novak, D. P., 56 Novak, R. A., 102 Novikov, B. G., 232 Novick, S. E., 292 Novoselov, V. S., 100 Novoselova, A. V., 107 Novruzova, F. M., 104, 269 Nowatari, H., 157 Nowicki, P., 277 Noyes, R. M., 235 Nozaki, T., 271 Numrich, R. W., 11 Nuretdinov, I. A., 220 Oakes, V., 136 Oakley, R. T., 209 Oberhammer, H., 134, 200, Oberlin, A., 111 Oblath, R. M., 18, 236 O’Connor, E. M., 258 Odberg, L., 46 Oddon, Y., 108 Oddy, P. R., 89 Odell, K. J ., 156 Odent, G., 186 Odile, J . P., 219 Odinets, Z. K., 103, 186 Odom, J . D., 72,76, 190, 195 @ye, H. A., 102 Ogadzhanova, V. V., 183 Ogden, J . S., 97 Ogilvie, K. K., 214 O’Grady, B. V., 117 Oh, Y., 114 O’Hare, P. A. G., 287 Ohashi, S., 218 Ohkita, K., 112 Ohnaka, S., 121 Ohrt, J . M., 31 Ohtaki, H., 8 Ohtomo, H., 35 Oikawa, H., 125 Okabe, T., 254 Okamura, K., 110 Okanu, M., 271 Okuda, T., 266 Olah, G. A., 229, 241 Olie, K., 150 Olin, A., 233 Oliva, C., 28 Oliver, J . P., 27, 91 Olovsson, I., 289 Onak, T., 54, 59, 60 Onishi, T., 235 Ono, Y., 121 221 Onuma, S., 31 Onyszchuk, M., 161, 162 Opalovskii, A. A., 41, 238, Opferkuch, R., 295 Oppermann, H., 264 Orama, O., 221 Orel, B., 289 Orioli, P. L., 166 Orlander, P., 182 Orlova, G. M., 108, 269 Ortwein, R., 229 Osaki, K., 46, 49 Osipov, 0. A., 194 Osipova, L. F., 209 Oskam, A., 150 Oskotskaya, E. R., 100 Ospanov, A. U., 95 Ospici, A., 87 Ostoja Starzewski, K. H. A., Oswald, H. R., 126 Otani, S., 109 Othen, D. G., 144 Otto, A., 123 Ouchi, A,, 227 Outterson, G. G., 59 Ovcharenko, A. G., 173 Ovennan, L. E., 258 Owen, J . D., 23 Owens, C. M., 234 Owensby, D. A., 10 Oya, A., 109 Ozin, G. A., 174, 192 275 222 Pachali, K. E., 166, 226 Padberg, H. J ., 222 Paddock, N. L., 207,209,211 Paddon-Row, M. N., 83 Paetzold, P., 86 Paine, R. T., 286 Palazzi, M., 225 Palenik, G. J ., 102, 191 Palmer, R. A., 49 Pandolfi, L. J., 89 Paniccia, F., 18 Pannell, K. H., 30 Pannhorst, W., 95 Panov, A. S., 36 Panov, V. P., 181 Panster, P., 229 Panus, V. R., 108, 269 Pany, V., 178 Papin, G., 14 Papp, J . F., 115 Paques-Ledent, M. Th., 123, Pgris, J . M., 218 Parkanyi, C., 88 Parkash, A., 214 Parker, A. J., 10 Parker, D., 8 Parkhomenko, N. G., 78 Parlog, C., 175 225 Parmentier, M., 221 Parrett, F. W., 191 Parrisa, F. W., 49 Parry, G., 5 Parry, R. W., 76, 190, 198 Parthasarathy, R., 31 Partht?, E., 221 Passet, A. V., 62 Passmore, J., 239, 259, 263, 264, 277, 279 Pasteur, G. A., 217 Pasynkiewicz, S., 93, 94 Patel, K. S., 47 Patel, M. M., 11 Pathak, G. K., 51 Patil, J . N., 45 Patmore, D. J ., 207 Patzdova, V., 110 Paul, R. C., 27, 230, 241, 247, Paulat-Boschen, I., 166 Pauleau, Y., 144, 176 Pausch, H., 96 Pavlat, V., 266 Pavlenko, L. I., 91 Pawcett, J . P., 157 Pawlikowska-Czubak, J ., 252 Payan, F., 253 Peacock, L. A., 76, 189 Peacock, R. D., 293 Peacor, D. R., 197 Pearce, R., 90 Pearman, A. J ., 175 Pebler, J., 81, 137 Pedersen, L., 273 Pedersen, S. E., 108 Pedley, J . B., 82, 171 Pedregosa, J . C., 225 Peel, J . B., 81 Peel, T. E., 289 Pelizzi, C., 131 Pelizzi, G., 131, 233 Pell, S. D., 177 Pellacani, G. E., 229 Pellerito, L., 131 Pendleton, P., 122 Peng, T. C., 257 Pentinghaus, H., 95 Pepe, F., 39 Pepperberg, I. M., 54 Pkpin, C., 72 Perachon, G., 257 Perchard, J . P., 251 Perez, G., 231 Perfetti, G. A., 112 Perkampus, H. H., 228 Perkins, A. J ., 285 Perlson, B. D., 253 Permyakov, P. G., 15 Perot, G., 39 Perret, R., 216 Perrot, P., 166 Perry, R. A., 114 Pershikova, N. I., 173 255, 259 Author Index 311 Ragatz, P., 61, 63 Rahman, M. O., 29 Rais, J., 1 Rajeshwar, K., 178 Rakke, T., 232 Rakusaka, T., 86 Ramirez, F., 215 Rand, B. A., 138 Ramdhawa, H. S., 28 Range, K. J ., 102, 258, 261, Rankin, D. W. H., 75, 119, Rao, C. N. R., 15, 28 Rao, K. S., 35 Rao, Y. K., 111 Rapkin, A. I., 183, 277 Raston, C. L., 102, 226, 232 Ratcliffe, C. I., 135 Rauh, P. A., 88 Raveau, B., 124 Rawat, J . P., 217, 225 Rawlins, W. T., 117 Ray, A. K., 182 Ray, M. N., 53 Rayermann, P., 115 Rayment, I., 137 Raymond, K. N., 70 Raymonda, J . W., 272 Rayzant, J. D., 118 Razgon, E. S., 95 Razmerova, T. L., 285 Razuvaev, G. A., 156 Rea, J. R., 216 Rebbert, R. E., 273 Rebsch, M., 250 Rechsteiner, C. E., 273 Reddy, N. V. R., 28 Redoules, G., 145 Reeder, R. A., 21 Reedy, G. T., 177 Reeve, D. A., 111 Reeve, R. N., 199 Refaey, K. M. A., 117 Reigler, P. F., 89 Reikhsfel'd, V. O., 119 Reiner, M., 113 Reinhart, P. W., 117 Reinthaler, P., 217 Remborg, G., 248 Remy, J . C., 144, 176 Renard, J. J., 282 Rendle, D. F., 100 Renk, T., 83, 87 Reshetova, L. A., 164 Rethfeld, H., 36 Rettig, S. J., 29, 87, 101 Reuben, J., 49 Reuschenback, G., 190 Reuter, K., 145 Reutov, 0. A., 156 Rey, J . C., 18 Reznik, A. M., 98 Reznikov, I. L., 16 262 145, 150, 155, 196, 201 Pervov, V. S., 272 Petch, E. A., 48 Peters, D. G., 57 Peterson, J . L., 193 Peterson, P. E., 229, 252 Peterson, S. W., 27, 73 Petillon, F., 228 Petragnini, N., 270 Petrini, G., 260 Petrov, B. I., 146 Petterson, L., 224 Petukhova, L. P., 15 Petz, W., 81, 129 Pezat, M., 177 Phelps, J . P., 277 Proshin, N. A., 277 Philipot, E., 228, 266 Phillips, D. A., 182 Phillips, G. D. J ., 29 Phillips, R. C., 111, 125, 126, Phillips, S. E. V., 29 Piccaluga, G., 8 Pickard, J. M., 115 Pickering, M., 94 Picotin, G., 230 Pidcock, A., 156 Pierens, P., 255 Pierre, G., 270 Pilipovich, D., 282 Pimentel, G. C., 286 Pinchuk, A. M., 204 Pinchuk, V. V., 106 Pinna, G., 8 Piotis, P., 239 Piryutko, M. M., 216 Pistorius, C. W. F. T., 104 Pitt, C. G., 99 Pitton, O., 285 Pitts, J . N., 114 Pitzer, K. S., 295 Pizer, R., 26 Plakhotnik, V. N., 78, 81 Platte, C., 108 Plattner, E., 124 PleSek, J., 61, 63 Plettenberg, H., 280 Ploog, K., 6, 88 Plotkin, J . S., 61 Plug, C. M., 258 Plus, R., 46 Plyshevskii, Yu. S., 79 Plyushchev, V. E., 95 Podafa, B. P., 41 Podberezskaya, N. V., 136 Podgorski, A., 176 Podzolko, Yu. G., 214 Pkel , U., 204, 205 Pohl, S., 141, 200, 207, 256, Poix, P., 218 Pokrovskii, A. N., 255 Pola, J., 21 Polder, W., 207 133 258 Poletaev, E. V., 217 Poletaev, I. F., 255 Pollak, A., 294 Pollitz, S., 81 Pomel, R., 123 Pomeroy, R. K., 153 Pomianowski, A., 252 Poole, R. T., 280 Poonia, N. S., 178 Pope, M. T., 217 Popik, N. I., 118 Pople, J . A., 285, 286 Popov, A. I., 8, 24 Popov, V. I., 285 Porai-Koshits, M. A., 157 Porte, A. L., 205 Porter, R. F., 86 Porthault, M., 273 Portier, J., 177 Postlethwaite, D., 235 Potapov, V. K., 178 Potier, A., 102, 103 Potier, J., 184, 286 Power, P. P., 170, 191 Poziome, E. J., 113 Prasad, B. N., 9 Prasad, H. S., 40, 134 Preat, H., 149, 154 Presnyakova, V. M., 255 Pressl, K. D., 197, 204 Preston, K. F., 277 Pretzer, W. R., 62, 64, 65 Preut, H., 129, 160, 261 Prince, E., 165 Prins, R., 111 Pritzkow, H., 279 Prochaska, E. S., 276 Prochazka, V., 11 Prodan, L. I., 96, 217 Proinova, R., 282 Proshin, N. A., 183 Protas, J., 125 Protsenko, P. I., 18 Pshezhetskii, S. Ya., 282 Puchkova, V. V., 93 Puddephatt, R. J ., 169 Puelles, G. F., 225 Pulham, R. J ., 2, 5, 173 Puri, D. M., 214 Puri, J . K., 255 Puska, J., 166 Pytlewski, L. L., 214 Qayyon, M. A., 111 Quarterman, L. A., 286 Quicksall, C. O., 217 Raban, M., 29, 30 Rabenau, A., 264 Rabinowitz, M., 113, 295 Racette, K. C., 91 Radchenko, A. F., 77 Radeglia, R., 220 Radom, L., 83 312 Author Index Rhine, W. E., 27, 73 Ribes, M., 142, 258 Ricard, L., 231 Rkci, J. S., 215 Rice, C. E., 131, 217 Richards, J . A., 125, 126, 133, Richards, R. L., 175 Richardson; E. K., 263 Richardson, T. J., 294 Richman, M. H., 144 Richter, A., 86 Richter, W., 222 Rieger, P. H., 225 Riepe, W., 87 Rigin, V. I., 107, 234 Rigny, P., 272, 278 Rimmelin, P., 289 Rimsky, A., 102 Rinker, R. G., 177 Rinn, H. W., 89 Rinne, D., 241 Ritter, G., 251 Rizvi, S. S. A., 229 Roberts, C. B., 89 Roberts, D. K., 39 Roberts, R. F., 134 Robertson, A., 150 Robertson, B. E., 253 Robertson, G. B., 278 Robertson, G. N., 288 Robertson, S. D., 111 Robinson, W. R., 108, 131, Robinson, W. T., 46, 65, 68 Rochester, C. H., 39, 120, 121 Rodgers, A., 162 Rodgers, A. S., 115, 273 Rodicheva, G. V., 104, 217 Rodier, N., 233, 258 Rodin, V. I., 285 Rodley, G. A., 46 Rodriguez-Reinoso, F., 112 Roduner, E., 14, 40, 257 Rosch, L., 145, 146 Roesky, H. W., 211, 241, 243, 245, 248, 250 Rogers, H. N., 60 Rogers, M. T., 277 Rohrbasser, C., 99 Rohrer, D. C., 31 Romanova, N. V., 213 Rombach, N., 97 Romm, I. P., 98 Root, J . W., 115 Rosch, N., 238 Roschenthaler, G. V., 76 Roscoe, J . M., 234 Rose, F., 248 Rose, H., 208 Rosenberg, B. J., 117 Rosmus, P., 251 Rosolovskii, V. Ya., 93, 184, 168, 169 217 185, 282 Rossi, M., 181 Rothenberg, S., 286 Rottler, R., 90 Rouchy, J . P., 110 Roussel, B., 85 Roussel, R., 113 Row, J. P., 51 Rouxhet, P. G., 120 Rowland, F. S., 271 Roy, L., 113 Royce, B. S. H., 181 Roziere, J., 289 Roziere-Bories, M. T., 289 Rozsondai, B., 125 Rubtsov, E. M., 268 Ruddick, J . N., 132, 213 Rudolph, G., ‘162, 192 Rudolph, R. W., 62, 64, 65, Rudomino, M. V., 194 Riihl, W. J., 223 Ruelle, P., 286 Ruf, W., 81, 83 Ruisi, G., 131 Rundqvist, S., 188 Rungta, K. K., 251 Ruppersberg, H., 7 Ruppert, I., 203, 252 Rusach, E. B., 98, 137 Ruska, J ., 226 Russell, D. B., 253, 293 Russell, J . L., 286 Russell, T., 181 Russo, P. J., 244 Rustad, S., 283 Rustamov, P. G., 104, 257, Rutherford, J . A., 117 Rutherford, J . S., 253 Rycroft, D. S., 145 Rykova, G. A., 52 Rysanck, N., 142, 269 Ryschkewitsch, G. E., 54, 73, 72, 197 262, 269 75, 84 Sabelli, C., 79 Sabelli, N. H., 11 Sabrowsky, H., 108 Sacco, A., 181 Sadhukan, P., 13 Sadoua, N. I., 118 Sarnstrand, C., 231 Safonov, V. V., 267 Sagnes, R., 289 Saibova, M. T., 186 Saito, H., 209 Saito, K., 126, 256 Saito, Y., 31 Saiton, E., 112 Sakamaki, T., 26 Sakk, Zh. G., 180 Sakurai, H., 152 Salama, S. B., 260 Salentine, C. G., 66, 68, 70 Salikhov, V. D., 100 Salomon, M., 8 Saltykova, E. A., 7 Salvatori, T., 90 Sammour, H. M., 35 Sams, J . R., 132, 213, 278 Santry, D. P., 285 Samsonova, T. I., 101 Sanchez, M., 199 Sandau, R. S., 47 Sandau, S. S., 47 Sandler, G. Yu., 16 Sands, D. E., 36 Sandulescu, D., 175 Saran, M. S., 244 Saratov, I. E., 119 Sarig, S., 113 Sasaki, A., 25 Sasaki, Y., 111, 124, 254 Satge, J ., 145 Sato, M., 120 Satterthwait, A., 214 Saturnini, D. J ., 59 Sau, A. C., 211 Sauvage, J. P., 25 Sauer, M. C., 280 Savage, W. J., 119, 263 Savel’ev, V. P., 262 Savenkova, M. A., 217 Saviotti, P. P., 32 Savranskii, V. V., 178 Sawa, V. I., 18 Sawitzki, G., 147 Sawodny, W., 237, 278 Sawyer, A. K., 119 Saxena, R. C., 120 Sayler, A. A., 62 Schaaf, T. F., 27, 234 Schack, C. J., 187, 198, 237, 278, 280, 282, 286 Schadow, H., 208 Schafer, H., 37, 105, 141, 259, 262, 275 Schaefer, H. F., 157,- 177, 276 Schaeffer, C. D., 139, 153 Schaeffer, R., 55, 61, 63, 196 Schaper, W., 243 Scheler, H., 208 Scherer, 0. J., 201, 212, 248 Schiavello, M., 39 Schiff, H. I., 117 Schinzel, K., 6, 103 Schioberg, D., 236 Schlapfer, C. W., 99 Schlak, O., 204, 205, 206 Schlingmann, M., 223 Schmeisser, M., 280 Schmid, E., 212 Schmid, G., 150, 188, 251 Schmid, H. G., 221 Schmidbaur, H., 193, 222 Schmidpeter, A., 210, 216 Author Index 313 Schmidt, A., 181, 197, 204, 229, 230, 231 Schmidt, D. L., 89 Schmidt, M., 259 Schmitz-Du Mont, O., 177 Schmutz, J . L., 209 Schmutzler, R., 197, 198, 204, Schnabl, G., 212 Schneider, G. R., 115, 271 Schneider, H., 95 Schnockel, Hg., 97 Schonberger, E., 228 Schanfeld, B., 231 Schonig, G., 212 Schoening, R. C., 8 Scholl, E., 86 Schollhorn, R., 16 Schomburg, D., 215 Schram, E. P., 146, 156 Schramm, W., 248 Schrauzer, G. N., 174, 291 Schrobilgen, G. J., 81, 292, Schroder, H. Fr., 204 Schroeder, L. W., 165 Schriider, S., 73 Schubert, U., ,175 Schuit, G. C. A., 290 Schultheiss, H., 181 Schultz, G., 125 Schulz, P., 266 Schulze, J., 220 Schumann, H., 145, 162, 192, Schumcher, H. J., 240 Schwager, I., 191 Schwartz, M. E., 8, Schwan, W., 105 Schwarz, W. H. E., 293 Schwebel, A., 112 Schwering, H. U., 100 Scollary, G. R., 90, 156 Scott, A. C., 184 Scott, G. A., 119 Scrivanti, A., 94, 162 Scully, T. F., 217 Scurrell, M. S., 39 Seale, S. K., 96 Secoo, F., 255 Seddon, K. R., 74 Seel, F., 199 Seeley, F. G., 1 Seff, K., 33 Sehgal, S. M., 79 Seidova, N. A,, 269 Seifert, H. J., 41 Seip, H. M., 80, 146 Seip, R., 80 Seiwell, L. P., 157 Selig, H., 113, 284, 295 Selivanova, N. M., 260 Sellmann, D., 175, 178 Selte, K., 221 205, 206 293, 295 195, 196 Selucky, P., 1 Semenenko, K. N., 55,91,178 Semenova, L. N., 179 Sementsova, D. V., 41, 255 Semkow, A. M., 11 Semples, R. E., 120 Sen, D. N., 45 Sendoda, Y., 121 Sengupta, A. K., 44 Sepelev, J. F., 123 Seppelt, K., 222, 240, 259, 266, 294 Serushkin, 1. L., 285 Sera, K., 135 Seredenko, V. I., 85 Sergeeva, A. N., 91 Sergent, M., 188 Serwatowski, J., 94 Setkina, V. N., 137 Setter, J ., 97, 104 Settle, J. L., 281 Setton, R., 113 Seufert, A., 82 Seyferth, D., 158 Shagalov, A. Yu., 271 Shaidarbekova, Zh. K., 104, Shakhbakov, M. G., 269 Sham, T. K., 134, 154 Shanko, A. N., 156 Shannon, R. D., 141, 258 Shanzer, A., 240 Sharma, P., 230 Sharma, R. D., 230, 247 Sharma, R. R., 39 Sharma, S. B., 145 Sharov, V. A., 180 Sharp, D. W. A., 281 Sharp, G. J., 171 Sharp, K. G., 191 Shaw, B. L., 57 Shaw, R. A., 202, 206, 207, Shcherbakov, V. A., 9 Shchori, E., 25 Shearer, H. M. M., 30, 44, 48, Sheft, I., 285 Sheldrick, G. M., 218, 219 Sheldrick, W. S., 215 Shen, Q., 117, 134, 193 Shenav, H., 196 Sheppard, N., 14, 288 Sherwood, R. C., 217 Shevchenko, V. N., 275 Shevchuk, V. G., 255 Sheverdina, N. I., 135 Shibata, S., 31 Shilkin, S. P., 55, 91, 178 Shilov, A. E., 173 Shilova, A. K., 173 Shimada, S., 122 Shimamura, A., 271 Shimazu, K., 39 217 208, 211 137 Shimida, M., 168 Shimizu, K., 122 Shimoishi, Y., 259 Shirk, A. E., 97 Shirk, J . S., 97 Shirley, D. A., 284 Shirokova, G. N., 93, 184 Shiryaev, V. I., 135, 161 Shoemaker, A. L., 91 Shore, S. G., 48, 55, 58, 59 Shortridge, R. G., 116 Shpanko, V. I., 277, 278 Shpinel’, V. S., 101 Shreeve, J . M., 240, 242, 256 Shrimanker, K., 179 Shrivastava, L. N., 260 Shriver, D. F., 230, 252 Shtepanek, A. S., 202 Shternina, E. B., 52 Shu, P., 83 Shukla, A. K., 15, Shulyatikov, B. V., 253 Shumov, Yu. S., 235 Shur, V. B., 175 Shurvell, H. F., 56 Shvets, A. A., 194 Sidorov, I. A., 262 Siebert, H., 283 Siebert, W., 80, 81, 83, 87, Siedle, A. R., 63 Sienko, M. J., 262 Sille, F., 100, 227 Silver, J., 170 Silveston, P. L., 251 Sim, W., 116 Simeral, L., 8 Simm, I. G., 115 Simmons, N. P. C., 191 Simon, A., 6, 12 Simonaitis, R., 236, 273 Simonetta, M., 28 Simpson, J ., 154 Sinaiko, V. A., 95 Sinensky, G., 112, 273 Singh, C. B., 123 Singh, H., 230 Singh, J . P., 225 Singh, M. M., 9 Singh, N. P., 9 Singh, P., 10 Singh, P. P., 145 Singh, U. C., 255 Singollitou-Kourakov, A., 143 Sinn, E., 70 Sinnarkar, N. D., 53 Sirotinkin, S. P., 255 Skabichevskii, P. A., 10 Skiba, 0. V., 16 Skidmore, D. R., 115 Skolnik, E. G., 271 Skripachev, I. V., 237 Skrivanek, J., 11 Skvortsov, V. G., 79 169 3 14 Author Index Slama, I., 171 Slater, J . A., 55 Sleight, A. W., 232 Slezak, J ., 102 Slim, D. R., 229, 263 Slivnik, J ., 282, 293, 295, 296 Slizkii, S. M., 81 Smalc, A., 282, 293, 295 Smardzewski, R. R., 238, 278, Smart, R. St. C., 14 Smart, L. E., 97, 138 Smid, J ., 25 Smirnov, M. V., 16 Smirnova, T. G., 255 Smith, B. E., 56 Smith, B. T., 136, 264 Smith, C. H., 164 Smith, E. B., 234 Smith, G. D. W., 235 Smith, G. M., 31 Smith, G. R., 28 Smith, J . A. S., 13, 222 Smith, J . D., 77, 91 Smith, L. R., 189 Smith, R. A., 29, 33 Smith, V. H., 238 Smith, W. L., 64 Smith, Z., 146 Smolin, J . I., 123 Smutek, M., 254 Sneddon, L. G., 61 Snover, J . A., 89 Snyder, S. C., 114 Sobolev, V. M., 175 Soboleva, L. V., 183 Sokolov, V. I., 156 Soliman, M., 145 Solouki, B., 251 Sommer, J ., 289 Sommer, P., 116 Soling, H., 103 Solov’ev, S. I., 98 Solovova, 0. I., 209 Sorokin, Yu. A., 146 Sorum, H., 49 Sotnikova, M. N., 101 Sourisseau, C., 82 Sowerby, D. B., 210 Sowerby, J . D., 44 Spears, K. G., 8 Spek, A. L., 140, 148 Spekkens, P., 260, 283 Spencer, J. L., 67, 68 Spiess, H. W., 288 Spinner, E., 32, Spiridonov, V. P., 99 Spitsyn, V. I., 95 Spitzer, U. A., 289 Spohr, R., 284 Sporzinski, A., 93 Sprenger, G. H., 240 Springer, C. S., 94 Springer, J . P., 214 282 Sprintschnik, G., 291 Sprintschnik, H. W., 291 Srivastava, S. G., 99 Stadelmann, W., 204 Sdlhandske, C., 219 Stahl, I., 242 Stalick, J . K., 217 Stallings, W., 146 Stampf, E. J ., 72 Stanko, V. I., 62 Stanley, H. E., 29 Stark, J ., 241 Starke, K., 47 Starowieyski, K. B., 93 Stas, N. F., 185 Steblevskii, A. V., 77 Stec, K. S., 290 Steckel, L. M., 88 Stedman, G., 244 Steele, B. R., 156 Steger, J., 219 Stein, L., 182 Steinback, E., 286 Steinberg, M., 111 Steiner, E. C., 51 Steiner, W., 162 Steinheider, G., 231 Stelzer, O., 76, 204 Stephens, M., 192 Stephenson, T. A., 263 Stepin, B. D., 255 Stepina, E. M., 135 Sterlyadkina, Z. K., 56 Sternberg, J . C., 277 Steudel, R., 237, 248, 250 Stevie, F. A., 294 Stewart, R., 289 Stibr, B., 61 Stidham, H. D., 123 Stilbs, P., 81 Stillman, M. J., 124 Stobart, S. R., 162 Stone, F. G. A., 67, 68, 70 Stone, F. S., 39 Stoneham, A. M., 3, 39 Storch, W., 75, 76, 88 Storr, A., 100, 101 Stover, G., 264 Strahle, J., 133, 172 Strathdee, G. G., 256 Stratten, L. W., 114 Straughan, B. P., 191 Strouse, C. E., 66 Striiver, W., 192 Stucky, G., 19, 27, 73 Studnev, Yu. N., 183, 277 Stufkens, D. J ., 175 Stumpp, E., 113 Su, Y. Y., 158 Subba Rao, M., 131 Subbiah, L., 230 Subrt, J ., 11 Suehiro, K., 135 Suga, H., 116 Sukhoverkhov, V. F., 277,278 Sullivan, J . M., 203 Sun, M. S., 191 Sunder, W. A., 187 Sundermeyer, W., 242, 243 Suradi, S. El., 253 Surat, L. L., 255 Sutherland, H. H., 104, 268, Suzuki, K., 110 Svensson, C., 261 Swaddle, T. W., 255 Symons, M. C. R., 8, 276 Szamrej, I., 256 Szele, I., 215 Szwarc, M., 19, 21 Szymanski, A., 176 269 Taesler, I., 289 Taga, T., 49 Takahashi, H., 112 Takanova, N. D., 278 Takeda, M., 264 Takeda, Y., 25 Takeda, Y. I., 143 Takei, Y., 254 Takeo, H., 116 Takeshita, H., 120 Takeshita, K., 109 Takeshita, N., 112 Takeshita, T., 116 Takezana, N., 39 Taki, K., 111 Tal’roze, V. L., 115 Tamai, Y., 110 Tamaru, K., 235 Tamas, J., 158 Tamuyzer, E., 95 Tamomkol, S., 49 Tamura, S., 40 Tanabe, K., 39, 290 Tanaka, K., 118, 143 Tanaka, M., 217 Tanaka, T., 139, 143 Tanake, Y., 39 Tananaev, I. V., 104,217,260 Tang, S. Y., 251 Tang, Y. N., 158 Tanguy, B., 177 Tantot, G., 278, 282, 283 Tarakanov, B. M., 251 Tariq, S. A., 18, 186 Tarte, P., 123, 184 Tatsumi, T., 174, 175 Tattershall, B. W., 277 Taube, H., 256 Taylor, B. F., 67 Taylor, D., 122 Taylor, D. J., 138 Taylor, J . B., 233 Taylor, P., 229, 239, 263, 279, Taylor, R. C., 194 Tebbe, K. F., 36 280 Author Index 315 Tedoradze, G. A., 285 Teichman, R. A., 244 Teichmann, H., 220 Temme, F. P., 13 Templeton, D. H., 237, 294 Templeton, L. K., 237, 294 Teplov, V. G., 95 Terada, K., 89 Terauds, K., 81 Tereshchenko, L. Ya., 181 Tereshkevich, M. O., 8 Terhell, J . C. J . M., 102 Terlan, A., 113 Terriere, G., 11 1 Teske, C. L., 142 Tevault, D., 161, 173 Tewari, P. H., 255 Thakur, K. P., 14 Thakur, L., 14 Thevet, F., 159, 258 Thiedemann, K. U., 188 Thielemann, H., 276 Thind, P. S., 217 Thoma R. E., 273 Thomas, B., 208 Thomas, C. M. S. R. 234 Thomas, D., 233 Thomas, J., 182 Thomas, K. M., 91, 169 Thomas-David, G., 45 Thompson, A. J ., 124 Thompson, D. A., 62, 72 Thompson, J . W., 272 Thompson, M. F., 21 Thornton, E. W., 121, 122 Thourey, J., 257 Thumova, M., 255 Thunder, A. E., 2 Thura, H., 166 Thurn, H., 226 Tikhonova, 1. A., 175 Timms, P. L., 174 Tinhof, W., 85 Titov, L. G., 267 Titova, K. V., 185 Tittle, B., 239 Toby, F. S., 115 Toby, S., 115 Todd, L. J., 63 Tofield, B. C., 217 Tokman, I. A., 217 Tolls, E., 189, 218 Tolstova, V. A., 258 Tomaja, D. L., 136 Tomilov, N. P., 101 Tominaga, H., 174 Toone, J. W., 289 Topfield, B. C., 131 Topp, W. C., 286 Tordjman, I., 165, 216 Torroni, S., 153 Tossell, J. A., 40 Tossidis, I., 143, 217 Totani, T., 86 Touhara, H., 286 TournC, C., 223 TournC, G., 223 Touzain, Ph., 113 Tracy, V. L., 130 Tracy, V. M., 129 Tranquard, A., 107, 108, 286 Tran Qui, D., 41 Trenkel, M., 259 Trevillion, E. A., 5, 173 Trewin, A. M., 153 Tribalat, S., 1 Tri m, D. L., 111 Trindle, C., 54 Triplett, K., 147, 153 Troester, J . H., 238 Tromel, M., 267 Trommsdorff, K. U., 279 Trotter, J., 29, 87, 100, 101, Truhlar, D. G., 11 Truter, M. R., 25, 34 Tsai, P., 161 Tsay, Y. H., 87 Tschetter, M. J., 7 Tsekhanskii, R. S., 79 Tsiklina, N. D., 255 Tsubokawa, N., 112 Tsuchida, T., 95 Tsuda, M., 286 Tsurikov, A. A., 269 Tsutsui, M., 125 Tsutsumi, K., 120 Tsvigunov, A. N., 178 Tuchagues, J . P., 82 Tuck, D. G., 103, 104, 105, Tul’chinskii, V. B., 81 Tulinsky, A., 144 Tulupov, V. A., 178 Tupikov, V. I., 282 Turevskaya, E. P., 107 Turner, A. K., 18, 236 Turner, C. A., 55 Turner, R. C., 93, 96 Turney, T. W., 174 Turova, N. Ya., 107 Tusek, Lj., 22 Tyler, D. R., 275 Tyler, R. J ., 111 Tyrlik, S., 174 Tzschach, A., 129, 221 Uchida, Y., 174, 175 Uchtman, V. A., 215 Udupa, M. R., 183, 186 Uebel, R., 205 Ujszaszy, K., 158 Ukhanov, S. E., 74 Ulbrecht, V., 283 Ulbrich, H. H., 79, 124 Ullmann, R., 85, 202 Umemoto, K., 25 Ungaro, R., 25 136, 211 117 Ungemach, S. R., 276 Unger, B. D., 177 Upadhyay, R. K., 120 Urch, D. S., 38 Urrutia, G., 10 Uskova, A. A., 278 Uspenskaya, K. S., 109 Ustynyuk, N. A., 137 Utkina, 0. N., 253 Utsunomiya, T., 184 Vadja, E., 158 Vahrenkamp, H., 78 Vaidya, V. G., 35 Valentini, J . J ., 272, 276 Valigi, M., 39 Valueva, Z. P., 98 Van Allen, J . W., 272 van Baar, J . F., 175 van Bolhuis, F., 212 van Cauteren, M., 229 Vancea, L., 153 van de Grampel, J . C., 212, Vande Griend, L. J ., 196,290 van den Berg, J . B., 212 van den Broek, E. G., 4 van den Graaf, F., 14 van den Hark, Th. E. M., 21 van der Kelen, G. P., 77, 150, van der Meer, H., 96 van Hecke, P., 288 van Hummel, G. J ., 46 van Ingen Schenau, A. D., 41 van Koten, G., 140, 141 van Lith, H., 4 van Remoortere, F. P., 51 van Roode, J . H. G., 132,213 van Schalkwyk, G., 266 van Vucht, J . H. N., 6 van Wazer, J . R., 222 Varekh, V. V., 81 Varfolomeev, M. B.,101, 267 Varma, R., 134, 182 Varnek, V. A., 157 Vasapollo, G., 181 Vasile, M. J., 294 Vasil’ev, V. G., 253 Vasil’ev, V. P., 52, 96, 285 Vasil’eva, M. G., 183 Vasina, E. A., 36 Vastola, F. J ., 111 Vedrine, J . C., 235 Vekris, J. E., 246, 263 Veleckis, E., 2, 173 Vel’mozhnyi, I. S., 186 Veltman, H., 116, 192 Vencl, J ., 119 Venkatarao, K., 255 Venturini, M., 255 Verdier, P., 100, 101, 177, Vereschagina, V. I., 96 213 15 1 220 316 Author Index Verkade, J . G., 196, 204, 214, Verma, R. D., 241, 247 Verneker, V. R. P., 178 Verschoor, G. C., 41, 258 Veysey, S. W., 271 Vicat, J ., 41 Vidal, J . L., 75 Vidal, M., 82 Vidrine, D. W., 229, 252 Vidyarthi, S. K., 118 Vignalou, J . R., 108 Vijh, A. K., 285 Vilkov, L. V., 99, 118 Vilminot, S., 159 Vincent, C. A., 9 Vincent, H., 141, 218, 220, 247, 258, 262 Vinogradov, E. E., 8, 78 Vinogradova, G. Z., 269 Vinogradova, S. V., 209 Vioux, A., 154 Virlet, J ., 278, 282 Vitse, P., 102, 230 Vittori, O., 273 Vivdenko, N. I., 275 Vlasse, M., 177 Vollenke, H., 124 Vogrin, F. J ., 10, Volgnandt, P., 181, 231 Vol’kenshtein, M. V., 175 Volkov, V. L., 62, 79, 255 Volodina, A. N., 260 Vol’pin, M. E., 175 von Criegern, T., 216 von Felten, H., 283 von Gustorf, E. A. K., 162 von Lehmann, T., 83 von Schnering, H. G., 37, 144, von Wazer, J . R., 189 von Zelewsky, A., 19 Vorob’eva, N. V., 16 Voronkov, M. G., 129 Voss, G., 248 Vrieze, K., 175 Vroom, D. A., 117 Vyanzankin, N. S., 145 290 147, 188, 227 Waddington, T. C., 129, 130, 135, 192, 199 Wade, K., 30, 44, 48, 144 Wagner, A. J ., 207 Wagner, D. L., 246 Wagner, H., 246 Wagner, H. G., 271 Wagner, Z., 125 Wahl, A. C., 11, 117 Wait, K., 207 Wakihara, M., 16 Walczik, M., 19 Walker, M. L., 213 Walker, N. S., 199 Walker, P. L., 111 Wallace, W. E., 116 Wallbridge, M. G. H., 81, 89 Waller, R. A., 116 Walrafen, G. E., 120 Walsh, E. J ., 209 Walsh, J . L., 43, 58 Walsh, R., 118, 119 Walter, K. G., 194 Walther, B., 107 Walton, D. R. M., 119, 148 Walton, P. D., 104, 269 Walton, R. A., 275 Wan, C., 79, 124 Wan, E., 60 Wang, S. M., 44 Wang, Y., 233 Wanklyn, B. M., 122 Wannagat, U., 213, 223 Warburton, A. P., 109 Ward, J . R., 235 Warnatz, J., 271 Warning, U., 192 Wartel, M., 255 Warthmann, W. W., 231 Washburn, B., 74 Wasif, S., 260 Wasilczyk, G. J ., 14, 257 Watanabe, H., 86 Watanabe, N., 15, 143, 285, Watanabe, T., 46 Waterlood, H. J ., 11 1 Waterstrat, R. M., 221 Watkins, B. F., 279 Watson, R., 114 Wayda, A., 45 Wazeer, M. I. M., 205, 206 Weakley, T. J. R., 46, 138 Webb, M. J., 153 Weber, D., 189 Weber, J . H., 171 Webster, D. E., 152 Webster, M., 138 Wedd, A. G., 174 Weddigen, G., 14 Weeks, C. M., 31 Weidig, C., 73 Weidlein, J ., 82, 100, 105, 212, 214, 227, 230 fieisenburger, S., 11 1 Weiss, A., 93 Weiss, J., 247, 248 Weiss, J .-V., 198 Weiss, L. C., 54 Weiss, R., 65, 231 Weitner, W., 88 Welch, A. J ., 67, 68, 69, 70 Welch, B. J., 17 Weleman, N., 259 Wellman, C. R., 235 Wells, C. F., 9 Wells, J . M., 118, 119 Wells, P. R., 149 Welz, E., 47 286 Werner, P., 212 Westerbeck, E., 12 Westheimer, F. H., 214, 215 Westrum, E. F., 288 Weulersse, J . M., 278 Wey, R., 95, 124 Whangbo, M. H., 238 Wharf, I., 161 Whidden, T. K., 239, 279 White, A. H., 102, 226, 232 White, J . W., 110 White, P., 239, 279 White, P. J ., 225 White, W. B., 123 Whitehead, G., 30, 48 Whitfield, H. J., 102 Whitlow, S. H., 105 Whitten, D. G., 291 Whittingham, A. C., 3 Wiberg, N., 180 Wichelhaus, W., 188 Widera, A., 37 Widler, H. J., 105, 230 Wieber, M., 224, 229, 232, Wiech, G., 88 Wiedemeier, H., 141, 262 Wieghardt, G., 14 Wieker, W., 122, 123, 245 Wightman, J . P., 112 Wignacourt, J . P., 98, 105 Wihler, H. D., 116, 192 Wilcsek, R. J. 78 Wilkins, C. J ., 193 Wilkinson, G. R., 254 Wilkins, R. G., 26 Williams, D. J ., 220 Williams, F., 191 Williams, J . K., 197 Williams, J . M., 236, 286, 289 Williams, R. E., 60 Williams, R. L., 271 Williams, W. J ., 272 Willis, C., 118 Willner, H., 259 Wilson, R. D., 136, 187, 280, 282, 286, 296 Wilson, W. W., 253, 278 Windhorst, K. A., 182 Winfield, J . M., 253, 278, 280, Wingfield, J . N., 23 Winter, G., 220 Winterstein, W., 83 Wisldff-Nilssen, E., 80 Witke, K., 73 Witman, M. W., 171 Wittman, A., 124 Wobke, B., 196 Woerlee, P., 14 Wojakewski, A., 269 Wolczanski, P. T., 291 Wold, A., 219 Wolf, E., 264 233 28 1 Author Index 317 Wolf, W., 6 Wolfbeis, O., 94, 162 Wolfgardt, P., 89, 90 Wolfsberger, W., 203 Wolmershavser, G., 248 Wolochowicz, I., 174 Wong, C. H., 44 Wood, R. A., 29 Wood, R. H., 98 Woods, M., 207, 211 Woodward, P., 14, 257 Woolf, A. A., 135, 281 Wortzala, H., 166, 216 Wrackmeyer, B., 54, 73, 149 Wright, C. A., 277 Wrighton, M. S., 291 Wu, C. H., 4, 114, 235 Wu, E. C., 115, 273 Wu, M., 168 Wudl, F., 31 Wuensch, B. J., 142 Wuyts, L. F., 150, 151 Wyatt, J . R., 114 Wynne, K. J ., 220 Yadav, S. R. P., 31 Yagubskii, E. B., 275 Yahav, G., 184, 290 Yajima, S., 110 Yakovlev, Yu. B., 103, 106 Yamada, K., 266 Yamaguchi, O., 122 Yamamoto, O., 90 Yamamura, H., 256 Yamanaka, S., 217 Yamaoka, S., 39 Yamauchi, M., 59 Yampolskii, M. Z., 100 Yancheskaya, I. A., 108, 269 Yankina, L. F., 214 Yankov, V. V., 135 Yano, R. T., 111 Yarbro, S. K., 241 Yaskelyainen, E. I., 16, Yasukawa, T., 184 Yasumori, I., 157 Yates, K., 198 Yatsenko, S. P., 7 Yatsurugi, Y., 120 Yeats, P. A., 278 Yetman, R. R., 72 Yokobayashi, H., 47 Yokokawa, T., 40 Yokozeki, A., 114 Yonco, R. M., 2, 173 Yoshii, M., 123 Yoshii, N., 39 Yow, H. Y., 197 Yu, H. S., 207 Yu, S. L., 240 Yudanov, N. F., 277 Yurchenko, E. N., 157 Yushchenko, S. F., 103, 185 Yutronic, N., 218 Yuzhakova, G. A., 74 Yvon, K., 221 Zabradskii, Yu. R., 275 Zagryazkin, V. N., 36 Zaitsev, B. E., 103, 185, 186 Zaitsev, V. A., 285 Zaitsev, V. M., 268 Zak, Z., 78 Zakhar’ev, Yu. V., 41, 238 Zakharkhin, L. I., 62 Zakharov, I. I., 175 Zakharova, I. A., 214 Zakolodyazhnaya, 0. V., 262 Zalkin, A., 36, 68, 237 Zambonin, P. G., 18 Zamankhan, H., 248, 250 Zander, R., 273 Zemskov, S. V., 294 Zemva, B., 293,294,295,296 Zanne, M., 37 Zarubitskaya, L. I., 17 Zasorina, V. A., 202 Zdanovich, V. I., 137 Zecchina, A., 39 Zeck, 0. F., 158 Zeegers-Huyskens, Th., 229 Zeiss, W., 206 Zemlyanskii, N. N., 135 Zenchenko, D. A., 103, 106 Zettler, F., 81, 87 Zetzsch, C., 271 Zhakaeva, A. Z., 137 Zharkov, A. P., 100 Zharkov, V. V., 164 Zhigareva, G. G., 62 Zhmurova, I. N., 202, 204 Zhodzishskii, G. A., 181 Zhuk, M. I., 225 Zhuk, S. Ya., 93, 184 Ziemann, H., 260 Zil’bennan, B. D., 288 Zink, J . I., 107 Zloczysh, S., 134 Zlomanov, V. P., 262 Zolotareva, L. V., 96 Zschunke, A., 129 Zubov, V. V., 181 Zubova, E. V., 178 Zuckerman, J . J., 136, 139, Zundel, G., 236 Zupan, M., 294 ZULU, A. P., 46 144, 162