ISSN:0260-1818    

DOI:10.1039/IC99289FX001

出版商:RSC    

年代:1992

数据来源: RSC

ISSN:0260-1818    

DOI:10.1039/IC99289BX003

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

3 Al Ga In and TI By J. P. MAHER School of Chemistry University of Bristol Bristol BS8 7 TS UK The references for this chapter have been obtained largely by means of a computer- based search of the literature this gave 3600 references (!) with 70% referencing aluminium 15% gallium 10% indium and 5% thallium. A large proportion of aluminium work concerns metals alloys and their properties or the catalytic properties of various materials involving alumina where the alumina usually acts as a support material. The interest in gallium and to a lesser extent indium comes with the many semiconductor materials and devices. The rather low number of thallium references is perhaps surprising in view of interest in ‘low temperature’ superconduct- ing materials. Necessarily then this review is only a small selection of the work which caught the authors’ attention during the search and subsequent perusal of the journals.The chapter is subdivided according to compounds and interest areas rather than the particular Group 13 element. 1 Organometallic Highlights The organometallic chemistry of Group 13 is well reviewed each year,’ so I will only mention some of the more interesting new compounds which have been prepared during 1992. The first optically active organoaluminum alkoxides R,AlOR’ (R = Me Et Bu’; OR’ = 1-mentholate and 1-borneolate) have been prepared. The aza-18-crown-6 derivative Me,AI(N ,C,)AlMe, has both hexa- and tetra- coordinate al~miniums.~ One A1 atom is bonded to two Me groups the N atom and the two crown ether oxygen atoms nearest to the N atom the other A1 atom is bonded to three Me groups and the N atom.The first neopentyl-aminoalanes [Neo,Al- N (H )Ada] , [Neo,AI -N(H)Ph’1, [Neo ,A1-N-(H )P h (Pr ),], and [Neo,A1-N (H )-Bu‘], (Neo = CH,CMe, Ph’ = various phenyl derivatives Ada = l-adaman-tanamine (H,N-Ada)) have been ~repared;~ these are novel as sterically demanding alanes. The reactions of R,SiNH with R;AI has produced’ a new family of dimeric K. C. Mohy in ‘Organometallic Chemistry A Specialist Periodical Report’ The Royal Society of Chemistry 1991 20 56. M. L. Sierra. R.Kumar V. S.J. Demel arid J. P. Oliver Orgunornetallic,s 1992 11. 206. A. D. Pajerski T. P. Cleary M. Parvez,G. W. Gokel and H. G. Richey Jr. Orgunorneta/lic.s 1992.I1,1400.D. M. Choquette M. J.Timm. J. L. Hobbs M. M. Rahim K. J. Ahmed,and R. P. Planalp Oryunornerallics. 1992 11 529. R. L. Wells A. T. McPhail. and T. M. Speer Organornrtallics 1992. 11. 960. 23 24 J. P. Maher aluminum silylamides [R;AlN(H)SiR,] (R' = Me R = Ph, Et,; R' = Bu' R = Ph, R = Bu:H). The dimer [Et,AlAs-(SiMe,),], has been found6 to contain a planar A1-As-A1-As ring. The synthesis of various 5-membered ring organoalanes (aluminacyclopentanes) has been developed' using olefines or acetylenes and AlEt, assisted by catalytic amounts of Cp,ZrCl,. The first triorganoaluminum bis(phosphine) adduct with C3P2 pentacoordination at aluminum Al[o-(Ph,PCH,)C,H,], has been prepared.8 Two of the anionic phosphines act as chelating ligands spanning equatorial-(C atom) and axial-sites (P atom) the third phosphine is only carbon-bonded.The polymeric compound [(H,AI),(P(C,H 1)2CH2)2] also has trigonal bipyramidal aluminum centres with exceptionally long apical AI-P bonds.' The solid state structure of tris(trimethylsilyl)methylgallium,[Ga,(C(SiMe,),),] shows a tetrahedral Ga skeleton; the compound is stable in air for months and shows remarkable thermal stability." Reactions of BuiGa with elemental S Se or Te have been shown to give mixtures of interesting compounds among which are the cubanes [(Bu')GaS], [(Bu')GaSe], [(Bu')GaTe], and an octamer [(Bu')GaS],. '' The for- mation and structures of cage compounds which contain a central In,E cube [(Cp- (co2Fe)4In4Se,l [(CP(CO),M~)L~I%S~] [(CP (CO),Fe)4In4S4] 3 and [(CP(co)3-Mo),In,Te,] have also been described.' An organoindium compound with an In-Se bond [(Me,CCH,),InSePh], has been synthesized and characterized.' Most organoindium compounds are not air-stable however by incorporating a nitrogen base into the organic ligand air-stable pentacoordinate bis[3-(dimethylamino)propyl]indiumsare formed.l4 These are stabilized by intra-molecular nitrogen base coordination to the organoindium giving hexacoordinate indium atoms in a quasi-polymeric structure with one long In-N bond. 2 Nitrogen Ligands Group 13/Group 15 Lewis acid/base adducts are of great potential interest as precursors in the formation of epitaxial layers of 111-V materials by means of metal-organic chemical vapour deposition (MOCVD); this subject has been re-viewed.' AlCl,.xNH compounds are possible starting materials for the synthesis of AlN thus the reactions of melts of monoammine-aluminium chloride with ammonia have been investigated.16 They were found to react at 150°C to give [AlCl,(NH3),] [AICI,] for which an X-ray structure determination was carried out.AlCl reacts with Mg(NR,) to form Al,X,Mg[NEt,] (X = C1 Br) Al,X,(NR,) U. M. Dzhemiliv A. G. Ibragimov and A. B. Morozov J. Chem. Soc. Mendeleec Commun. 1992 1 26 U. M. Dzhemilev A.G. Ibragimov and A. P. Zolotarev J. Chem. Soc. Mendeleet. Commun. 1992,4 135. ' S. J. Schauer W. T. Pennington and G. H. Robinson Organometallics 1992 11 3287. G. Muller J. Lachmann and A. Rufinska Organomrtullics 1992 11. 2970. F.R.Bennett F.M. Elms M.G. Gardiner G.A. Koutsantonis C.L. Raston and N.K. Roberts Organometallics 1992 11 1457. 10 W. Uhl W. Hiller M. Layh and W. Schwarz. Angrw. Chern. Int. Ed. Enyl. 1992 31 1364. M. B. Power J. W. Ziller A. N. Tyler and A. R. Barron Organometullics 1992 11 1055. l2 K. Merzweiler F. Rudolph and L. Brands Z. Naturforsch. Teii B. 1992 47 470. 13 O.T. Beachley J. C. Lee. H. J. Gysling S. H. L. Chao M. R. Churchill. and C. H. Lake. Organometallics 1992 11 3144. l4 H. Schumann F. H. Gorlitz T. D. Seuss and W. Wassermann Chem. Ber. 1992 125 3. l5 D.K. Russell. Coord. Chem. Rev.. 1992 112. 131; F. Maury Adc. Muter.. 1991. 3. 542. l6 H. Jacobs and B. Nocker Z. Anorg. Ailg. Chem. 1992 614 25. All Ga in and T1 25 (R = Et Pri X = C1 Br) AlX,HNR (R = Pri); these were characterized by mass- infrared- and H-1 C-13 and A1-27 NMR spectroscopy and by elemental analyses." The crystal structures of AI,Cl,[NEt,] and AICl,HNPr' were determined.Infrared and Raman spectra of NaAl(NH,) and of deuterated samples have been measured.'* The high charge density of the AI3 ions causes the NH-stretching modes + to be shifted higher by as much as 200cm-' compared to those of free amide ions. Furthermore the H-bond donor strength of the NH ions are so enlarged that weak unusually long NH * * NH hydrogen bonds are formed. These H-bonds share layers of vertex-connected AI(NH,) and Na(NH,) tetrahedra within the structure. Evidence has been found during the electrochemical oxidation of indium metal in liquid ammonia solutions of NH,X (X = C1 Br or I) for formation of In" species at the anode." In the NH,I solutions Raman spectroscopy confirmed the presence of In214 but it was not possible to isolate neutral or anionic derivatives of In" since disproportionation occurs on removal of solvent to give In' In' and In"' derivatives.Solutions of NH,I with o-quinones gave InI3.3NH, while with substituted catechols the products were [NH,],[In(O2C6X4),]*Et20 [X = C1 or Br]. Another ortho-cathecol Bu:H,C,(OH) ( = (H,dbc)) gave the dimeric anion [1n,(db~),(NH,),]~- which involves two In0,N kernels with In,O cross-linking responsible for the dimerization. The treatment of p-tert-butylcalix[4]arene with [H,Al(NMe,)] results2' in trimetallation and deprotonation by the tertiary amine yielding the bis(calix[4]arene) [{ (1-H,)Al},][HNMe,], with included CH,Cl,.This unique calixC4)arene has a structure in which the distorted five-coordinate 0-bound aluminium centres fuse the slightly flattened cone calixarene units the methylene chloride H-atoms residing over two opposite aromatic rings in each cone involve a C-H . . n-arene interaction. There is continuing interest in niacrocyclic complexes of Ga"' and In"' thus the reaction of Li,(tmtaa) (tmtaa = dibenzotetramethyl-tetraaza[l4]annulene) with GaCl and InCl has been shown to give the complexes Ga(tmtaa)Cl and In(tmtaa)Cl re~pectively.~' The structure of the gallium complex was determined by X-ray analysis. The Ga-C1 bond is very unreactive but the In-Cl bond undergoes a slow reaction with MeLi to form In(tmtaa)Me.,l Various In"' and Tl"' porphyrin compounds have been investigated.Two new series of metal-metal bonded indium porphyrin complexes (tbpp)In-ML and (5fp)In-ML have been synthesized, (together with (oep)In-ML and tppln-ML) where tbpp is the dianion of 5,10,15,20-tetrakis(3,5-di-t-butylphenyl)porphyrin, 5fp is the dianion of 5,10,15,20-tetrakis(2,3,4,5,6-penta~uorophenyl)porphyrin, and ML is Mn(CO), Mo(CO),Cp and Co(CO),. The synthesis and characterization of In"' porphyrin complexes with three types of a-bonded tetraazolato axial ligands has been reported,, In(por)(N,CR) where R = CMe, CH=CH, or CH=CHCN and por = oep2-,tpp or 5,10,15,20-tetra-p-trifluoromethjlphenylporphyrin. The N,CR ligand of a given M(por).(N,CR) complex can have the R group attached to either the 4-or 5-position of l7 C.C.Chang S.C. Lin C. N. Tsai. and L. K. Liu J. Chin. Chem. SOL..(Toipri),1992 39 55. 18 H. D. Lutz N. Lange H. Jacobs and B. Yocker Z. Anorg. Allg. Chem. 1992. 613 83. '' T. A. Annan. J. S. Gu. Z. G. Tian and D. G. Tuck J. Chem. Soc.. Dalton Trans. 1992 3061. 2o J.L. Atwood S.G. Bott C. Jones and C. L. Raston J. Chrm. Soc,.,Chem. Commun. 1992 1349. *' D.A. Atwood V.O. Atwood A. H. Cowlry J. L. Atwood. and E. Roman. Inorg. Chem. 1992 31 3871. 22 S. Takagi Y. Kato H. Furuta S. Onaka and T. K. Miyarnoto J. Orgunomet. Chem. 1992 429. 287. 23 R. Guilard N. Jagerovic. A. Tabard.C. Naillon,and K. M. Kadish.J. Chem. Soc. Dalton Trans. 1992,1957. 26 J. P.Maher the tetraazolato ring. In the oxoporphyrin 5,15-dioxo-2,3,7,8,12,13,17,18-octaethyl-porphodimethene-thallium(rI1)chloride the structure consists of a penta-coordinated thallium ligated by the four nitrogens of the porpho-dimethene ligand and a chloride in the axial p~sition.'~ 3 Halogen Compounds An understanding of aluminofluoride and oxyfluoride melts is essential in the electrolytic smelting of aluminum as these are the precursors of fluoride glasses and are analogue systems for molten silicates. AI-27 NMR spectroscopy at high temperatures has been shown to provide important information about the species and their coordination numbers in aluminofluoride liquids as well as structural and dynamic changes in the crystalline fluoride^.,^ The thermal decomposition of [AIF,,,(OH),.(H,O)] depends strongly on the partial pressure of the gaseous reaction products and proceeds in three overlapping steps namely dehydration formation of amorphous A1203and metastable P-AIF, and formation of x-AIF and x-AI2O3. An exchange of F-and OH-also takes place. Whilst the main gaseous species are H,O and HF the gas phase complexes HAIF and H,AIF5 have also been observed.26 Of interest to writers of textbooks perhaps is the gas electron diffraction data recorded for GaCl and InCI, which is consistent with equilibrium structures of D,, symmetry and bond distances of rM-cl = 210.8(3) and 228.9(5) pm re~pectively.~' Bond energies and distances from the literature show that the M-CI bonds in MCI,, are stronger but longer than in MCI,(, for M = Al Ga or In.It was suggested that the relative weakness of the bonds in trivalent chlorides is due to the energy required to promote the Group 13 metal atoms from the 'P(s2p)ground states to 4P(sp2)valence states. The decreasing stability of trivalent relative to lower valency chlorides as the Groups are descended was associated with both increasing promotional energies and to decreasing M-CI bond strengths. TICI does not appear to exist in the gas phase. The first organic synthetic application mediated by Ga" as GaCI, has been described,' in a one-pot reductive Friedel-Craft type reaction; carbonyl compounds react with anisole to give alkylated anisoles in good yields. There has been a flurry of interest in complexes of In"' halides with various nitrogen and phosphorous based ligands.Thus the crystal structures of several 2,2'-bipyridyl complexes of InCI have been determined. The compounds [InCl,(bipy)(H,O)] [InCl,(bipy)(H20)].H20 and [InCl,(bipy)(EtOH)] are all Sac-octahedral. Lattice dimensions determined from powder data have been reported for another polymorphic modification of the [InCl,(bipy)(H,O)] complex.2" The six-coordinate indium complex [NHEt,][InCl,(dpt),] (Hdpt = 1,3-diphenyItriazene) has been reported.,' Reaction of Lewis bases L with the compound gives [InCl,(dpt)L,] L = py PEt, L = bipy phen dmpe or Et,PCH,CH,PEt,. The bidentate ligand adducts show a supramolecular architecture involving dipolar In-CI . . N interactions in the solid state. 24 M.O. Senge and K.M. Smith Z. Naturfbrsch.. Teil B 1992 47. 837. 25 J. F. Stebbins I. Farnan N. Dando. and S.Y. Tzeng J. Am. Ceram. Soc.. 1992 75 3001. 26 D. H. Menz. C. Mensing. W. Honk and H.G. Vonschnering Z. Anorq. Allq. Chern. 1992 611. 107. " A. Haaland A. Hammel. K.-G. Martinsen. J. Tremrnel and H. V. Volden. J. Chrm. Soc. Dalton Trans.. 1992 2209. " Y. Hashimoto K. Hirata N. Kihara M. Hasegawa and K. Saigo Trrrahrdron Lrrr.. 1992. 6351. 29 M.A. Malyarick S. P. Petrosyants and A. 9. Ilyuhin Polyhedron. 1992 11 1067. j0 J.T. Leman H. A. Roman. and A. R. Barron. J. Chrm. So(,.,Dalton Trans.. 1992 2183. AI Ga In and T1 The crystal structures of [In(bipy)Cl,(H,O)] [In(bipy)C1,(H,0)]~H20 and [In(bipy)C1,-(EtOH)]3' and of [InCl,(thiol),] complexes32 have been described.The first example of a trigonal bipyramidal type structure for an InI complex has been found in {p-[1,2-bis(diphenylphosphino)ethane]-1xP :2lcP')-bis[ 1,2-bis(diphe- nylphosphino)ethane]-1lcP,2lcP-bis[triiodoindium(r11)],and its crystal structure de- termined. The compound contains 1,2-bis(diphenyIphosphino)-ethaneligands bond- ing in two ways; firstly one ligand bridging between the two In atoms (bidentate) and secondly two ligands bonded to only one In atom each (m~nodcntate).~~ InI forms 1 1 adducts with various phosphine ligands [PR,; R = Bu', HPh, HBu; or H(cyclohexyl),]. Crystal structure on InI,.PHR (R = Ph or Bu') show the presence of four-coordinate indium atoms but also that intermolecular interactions (In-I-In P-H-I In-I-I-In) are present.Five-coordinate addition compounds of AH, that is AlI,L (L = acetone butanone cyclopentanone cyclohexanone benzal- dehyde and p-methylbenzaldehyde) have also been de~cribed.,~ The reactions between TIX (X = C1 Br or I) and substituted imidazoles { 2-met hyl-imidazole 2-phenyl-imidazole 2-ethyl-imidazole 1,2-dimet hyl-imidazole and 1 -methyl-2-phenyl-imidazole) have been studied and the complexes formed have been characterized. 36 The cis-hydride-chloride complex [(PP,)RuH(CI)] [PP = P(CH,CH,PPh,)J in CH,Cl has been found3' to extract the TIf ion from TlPF in the aqueous phase to give [(PP,)RuH(ClTl)]PF (Figure I) which contains a unique example of a TI' atom bonded to a C1 atom that acts as a bridging ligand; the crystal structure also shows pairs of these linked by a TIC1 bridge.Figure 1 4 Aqueous Solution Chemistry The bioinorganic chemistry and toxicology of All" in aqueous solution has been reviewed.,' This area of interest generates research into aqueous solution complexa- tion particularly with organic and bio-ligands relating to the purported link between Alzheimer's disease and aluminium. A1-27 NMR has been used in several studies of aqueous Al"' complexation by various ligands. With ascorbic acid a weak binary species AIL; together with two 31 A. B. Ilyukhin M. A. Malyarik. and S. P. Petrosyants Kristullogrufiyu 1992. 37. 663. 32 M.A. Malyarik A. B. Ilyukhin. S. P. Petrosyants. and Y.A. Buslaev Zh. Nrorg. Khim.. 1992. 37. 1504. 33 I. A. Degnan N. W. Alcock.S. M. Roe and M. G. H. Wallbridge Acfu Crystullogr..Sect. C 1992.48.995. 34 N. W. Alcock. I.A. Degnan 0.W. Howarth. and M. G. H. Wallbridge. J. Chem. Soc.,Dalton Truns. 1992 2775. 35 F.J. Arnaiz J. M. Bustillo and R. Lopez Synrh. React. Inorg. Metul-Org. Chem.. 1992 22 371. 36 M. R. Bermejo. M. I. Fernandez B. Fernaiidez. and M. E. Gomez. Synth. React. Inorg. Metul-Org. Chem.. 1992 22 759. 3 7 C. Bianchini. D. Masi K. Linn. C. Mealli. M. Peruzzini and F. Zanobini Inorg. Chem.. 1992. 31. 4036. 38 B. Corain. A. Tapparo. A. A. Sheikhosman. G.G. Bombi. P. Zatta. and M. Favarato Coord. Chem. Rev.. 1992 112 19; B. Corain. M. Nicolini P. Zatta ihid. 1992 112. 33. 28 J. P. Maher trinuclear mixed-hydroxo species [Al,(OH)4(H-1L)]3' and [A1,(OH)4(HlL)L]3f is formed.39 The coordination of Al"' and Ga"' with (+ )-(2R,3R)tartaric acid shows4' mononuclear 1 1 1 2 1 3 and dinuclear 2 :2 complexes with both octahedrally and tetrahedrally coordinated Al"'.The mononuclear 1 3 complex displays remarkable stability and symmetry owing to the formation of successive hydrogen bonds. Dinuclear di-tartrate-bridged complexes are favoured in tartrate solutions of Al"' and Gal1'. The chelated complex [Al(lactate),] dissolves in water to give stable acidic solutions where both free and metal-coordinated lactate ligands can be detected.41 Ligand exchange between metal-bonded and free lactate ligands was studied by H-1 NMR. At pH 7.5 the solutions are meta-stable slowly forming lactate and possibly metastable [Al(OH),(H,O),].The incorporation of fructose and of sucrose into an Al(OH) matrix has been investigated by various spectroscopic technique^.^^ Whereas fructose showed very good ability of binding to Al(OH), sucrose showed a much weaker binding tendency. A possible explanation is that fructose is bound to the Al(OH) matrix in p-pyranose and p-furanose forms but that sucrose is bound through its fructose part; in both adducts aluminium is octahedrally coordinated. An A1-27 NMR study of the binding of aluminium to the human serum proteins albumin and transferrin shows that approximately three A1"' ions are bound to each albumin.43 The albumin Al"' is octahedrally coordinated by oxygen atoms. However no recognizable signal was observed for Al"' bound to transferrin possibly because the bound Al"' exists in a site of low symmetry causing its NMR signal to be broadened by quadrupole-induced relaxation.Protanated chelates of Al Ga and In with propylene- diaminetetraacetic acid have been isolated and characterized by various methods.44 The ligand can be penta- or hexadentate. The A1 and Ga chelates appear to be isomorphous. The COOH is not ionized in the chelates. The stability constants for tris-bidentate chelates of 1-methyl-3-hydroxy-2-py-ridinone (mh,p) and 1,4-dihydroxy-2-pyridinone (dh,p) with Ga"' Al"' and In"' (also ~~111 GdlI1) have been determined.45 The proximity of the bidentate hydroxy oxygen donors to the pyridyl nitrogen atom of the ligand influences the 3 1 stabilities for each ion as the relative order of stability is dmhp > mh,p > dh,p (dmhp = 1,2-dimethyl-3-hydroxy-4-pyridinone).For these ligands the stability order is Fe"' > Ga"' > Al"' =-In"' > Gd"'. A low temperature H-1 and A1-27 NMR study of AI(CIO,) in aqueous mixtures of dimethylformamide and urea demonstrated that the Al"' is hexa-coordinated with monodentate binding from the oxygen atoms.46 In contrast to previous reports the A1-27 spectra for these solutions showed well resolved signals for the species [A1(H,0),-,L,]3+ (n = &6; L = dmf or urea) including two isomers for one of the wa ter-urea complexes. 39 L.O. Ohman and A. Nordin Acra Chem. Scund. Ser. B,1992 46 515. 40 F. R. Venerna J.A. Peters and H. Vanbekkurn Inorg. Chim. Acta. 1992.191 261 ihid. 1992. 197 I. 4' B. Corain B. Longato A. A. Sheikhosarn G. G. Bornbi and C. Macca. J. Chrm. Soc. Dalton Trans. 1992 169. 42 M. Tonkovic H. Bilinski and M. E. Smith Inorg. Chim. Acra. 1992 197 59. 43 S. Jernil A. Fatemi D. J. Williamson and G. R. Moore J. Inorg. Biochem.. 1992 46 35 44 S. B. Karweer 9.P. Pillai and R. K. Iyer fndiun J. Chem. Sect. A. 1992 30.1064. 45 E.T. Clarke and A. E. Martell Inorg. Chim.Acra 1992 1%. 185. 46 A. Fratiello V. Kubo-Anderson S. Azimi. C. Fowler E. Martinez R. Perrigan S. Shayegan and 9. Yao. Mayn. Reson. Chem.. 1992 30,280. Al Ga In and TI 29 The low temperature Ga-71 NMR spectra of aqueous solutions containing GaCI, C1- and Ga(CIO,) show4' clear evidence for the existence of octahedral complexes with mixed ligands [GaCl,(H,0),-,](3 -n)+.This is in contrast to the Raman spectra which only show signals of [GaCl,] -and [Ga(H20)J3 ions. + 5 Zeolites In order to help understand the chemical processes involved in the formation of gallosilicate zeolites alkyl-ammonium gallosilicates have been studied by using Si-29 and Ga-7 1 NMR in both aqueous and aqueous-dimethylsulfoxide solutions.48 Cyclic trimers a branched cyclic trimer and a double three-membered ring-anion with one incorporated Ga atom were observed. Due to the larger size of GaO unit compared to SO, gallosilicate anions with rather acute ( <90') SiO-Ga-OSi bond angles were found to be especially stable. Dimethylsulfoxide/water mixtures promote the forma- tion of ring silicate and gallosilicate anions.There was evidence for gallosiloxane (Si-0-Ga) bonds in some solutions. Aluminium has been replaced by gallium in zeolite b-frameworks and infrared measurements of the OH stretching band (3615-3625 cm- ')indicate that the Brernsted acid strength of the zeolites decreases as A1 is replaced by Ga in the frame~ork.,~ The gallium system is more effective at incorporating silicon than the aluminium system. Synthesis of the gallophosphate molecular sieve cloverite with a channel size of 20-tetrahedral-atoms has been described these zeolites are thermally stable and arc able to absorb large organic molecules.s0 Crystalline gallosilicates with a pentasil (MFI)framework containing Ga3' in lattice positions have been synthesized51 by the + hydrothermal technique using [Et,Bu"N] as template in the gel system Na,O :(Et,Bu"N),O :Ga,O :SiO H,O.A novel oxyfluorinated microporous gallophosphate [Ga,(PO,)(HPO,),F,(OH)~ C,N2H,,.0.5H,0] has been characterized. In this encapsulated 1,4-diazabicyclo C2.2.21octane (DABCO) acts as a template for synthesis.s2 6 Thallium-based Superconductors Though no more materials with exceptionally high values of T (the transition temperature to a superconductor) have been reported there is still great activity in this subject and a thallium compound T1,Ba,Ca2Cu,0,0 still holdss3 the record T, of 128K. Of possible relevance to the properties of the superconductors is the observation that thallic oxide-6 an oxide with high conductivity should be regarded as non-stoichiometric and deficient in oxygen.54 The single superconducting phase bulk 2234-type superconductor TI -x-Ba,Ca3 +xCu401 ,-8 was synthesized using a 2245-type composition in the precur- j7E.Brendler B. Thomas and S. Schonherr Monatsh. Chem.. 1992. 123 285. 4R R.F. Mortlock A.T. Bell. and C. J. Radke J. Phys. Chem. 1992 96 2968. 49 M.A. Camblor J. Perezpariente and V. Fornes Zeolites 1992 12 280. 50 Q. Huo and R. Xu J. Chem. Soc. Chem. Commun.. 1992 1391. '' S.V. Awate P.N. Joshi V. P. Shiralkar and A.N. Kotasthane J. Inch. Phenom. Mol. Recoyn. Chem. 1992 13 207. " T. Loiseau and G. Ferey J. Chem. Soc. Chem. Commun. 1992. 1197. " A.R. Armstrong and P. P. Edwards Annu. Rep. Prog. Chem.. Sect. C Phys. Chem. 1991. 88 259. 54 A.Goto H. Yasuoka. A. Hayashi and Y Ueda J. Phys. So<. Jpn.. 1992 61 1178. 30 J. P. Maher sor.' These show a T of 113K which can be increased by oxygen loading or by prolonged vacuum annealing to 1 16 K. Single phase bulk 2223-type samples were prepared T1 -x -,Ba,Ca +,Cu,O ~1' (0 < x < 0.4) whose structures are tetragonal. Thallium and oxygen deficiency was found; holes are due to Ca2+ substituting on the T13+ sites. The T was 112-1 18 K and was found to increase with increasing hole concentration. The origin of the holes for all these samples is due to Ca2+ substitution on the TI3+ sites.56 Similarly hole concentration and T were examined after synthesis of T1 -,Ba -,La,Cu06 -(0.00 < y < 0.35; 0.0 dz d0.2). During the oxygen annealing samples with y = 0.00 extruded thallium to form Tl,O and transformed from tetragonal to orthorhombic; samples with y = 0.35 did not extrude thallium.It was concluded that T1 extrusion to form Tl,O proceeds by an ordered removal of T1 until the Fermi energy falls below a mobility edge in the T1 6s band.57 Superconducting TI,-,CaBa,Cu,O can be prepared without impurity from the corresponding two T1-0 layer cuprate only when some TI deficiency is in~orporated.~' An X-ray structure determination of single crystals of 2201 -type thallium cuprate (T1,.,,Cu,,,,)Ba,Cu06 has been perf~rmed.,~ Various T,s were obtained up to 110 K. The TI atoms are partially replaced by Cu atoms and TI atoms and O(3) atoms linked with T1 are displaced from their symmetrical sites.A structure/properties correlation for 2201-type cuprate crystals was established. Not all of the thallium materials have high T values. Single crystals of (T1 .87Cu1 ,)Ba,06 + ,have been obtained6' by a CuO self-flux method. Composi- tions suggest substitution of Cu for TI; X-ray diffraction shows tetragonal symmetry. Site occupancy refinements indicate completely occupied Ba and Cu sites within the structure and displacements of the atoms in the T1,0 layers of this crystal. T is only 12.4K. A new series of 1222-type thallium-lead layered cuprate compounds (Tl,Pb)Sr,(Nd,Ce),Cu,O have been synthesized and characterized by X-ray powder diffraction.61 Their T is in the range 3MOK. 7 Metal-Metal Bonded Compounds Metal-metal bonds have been described between Group 13 compounds and a number of transition metal moieties.The ion [(,~'-1n)(Mn(C0>,),]~- formed by treatment of K,[Mn,(p-CO),(CO),,] with InCl, has an idealized pentagonal-planar coordination for indium (Figure 2); the reaction also yields an In,Mn cluster.62 The reaction between NaCo(CO) and R,GaCI with bulky alkyl groups gives6 the novel volatile Co-Ga complexes [(CO),CoGaR,(thf)] [R = CH,C(CH,), CH,Si(CH,),]. The Co-Ga bonds are highly reactive and rapidly cleaved by electrophiles or nucleophiles. The compounds may be used to generate intermetallic Co/Ga films by low-pressure MOCVD methods. 55 M. R. Presland J. L. Tallon P. W. Gilberd and R. S. Liu Physica C 1992 191 307. 56 M. Paranthaman M. Foldeaki and A. M. Hermann. Physica C 1992 192 161.5' M. Paranthaman A. Manthiram and J. B. Goodenough J. Mater. Chem. 1992 2. 317. " R. Vijayaraghaven J. Gopalakrishnan and C.N. R. Rao J. Mafer.Chem. 1992 2 327. 59 N. N. Kolesnikov V. E. Korotkov M. P. Kulakov R. P. Shibaeva V. N. Molchanov R. A. Tamazyan and V.I. Simonov Physicu C 1992 195 219. 6o R.S. Liu S. D. Hughes R. J. Angel T. P. Hackwell A. P. Mackenzie and P. P. Edwards Physicu C 1992 198 203. 6' Z. Y. Chen Y.Q. Tang Y. F. Li D. 0.Pederson and Z. Z. Sheng Mater. Res. Bull. 1992. 27 1049. 62 M. Schollenberger B. Nuber and M. L. Ziegler Angew. Chem. Int. Ed. Engl. 1992 31 350. 63 R.A. Fischer and J. Behm Chem. Ber. 1992 125. 37. AI Ga In and TI 31 Figure 2 In Tl[Fe(CO),(NO)] there are no TI-Fe or T1-TI covalent bonds rather discrete TI+ cations are well separated by [Fe(CO),(NO)] -anions in a distorted NaC1-like structure.64 The first indium-copper cluster [Ph,P][CU,In,(SEt),,] has been prepared by the reaction of [Cu(CH,CN),][PF,] with [Ph,P][In(SEt),]; its crystal structure shows an adamantoid framework reminiscent of the chalcopyrite structure of CUI~S,.~~ 8 Thallium(1) There have been several studies which involve the stereochemical behaviour of T1' ions and thallium lives up to J.B. A. Dumas' epithet -the ornithorhynicus of the elements! Two polymorphs are observed in complexes of TI' salts of the antibiotic lasalocid- A.66 One crystal form is a one-dimensional polymer [Tl+(lasalocid A-)In in which the TI+ is coordinated on one side to five oxygens of an ionophore molecule and on the other side to the phenyl ring of the neighbouring molecule however Tl+-phenyl q6-bonding is weak.The second form is a monomer [Tl+(lasalocid A-)I where the T1' ion is coordinated on one side to six oxygens of an anion ligand whereas the other side of the metal ion is uncoordinated and faces a nonpolar environment provided by hydrophobic alkyl groups of neighbouring molecules in the crystal structure. This is the first ionophore-metal complex that lacks three-dimensional nonpolar enclosure of the metal ion. TheT1'complexes[Tl([18]aneN,S4)]PF,and [T1([18]aneS,)]PF6 ([18]aneN,S = 1,4,10,13-tetrathia-7,16-diazacyclooctadecane, [18]aneS6 = 1,4,7,10,13,16-hexathia-cyclooctadecane) have been synthesized and their crystal structures determined.67 The complex structure of [TI([18]aneN,S4) PF shows the TI' ion occupying the 'cradle' formed by the macrocycle and bound uia an [N,S + S,] donor set; this leaves the top face of the metal centre exposed except for long-range interactions with two further thioether donor atoms from adjacent [T1([ 1 8]aneN,S4)] cations.In the complex + [TI([ 18]aneS6)]PF the structure shows TI' interacting with all six macrocyclic thioether donors with two of those interactions being considerably shorter than the other four. There are additional long-range interactions with two further thioether donors from adjacent [TI([ 18]aneS,)]' cations. There is also a long-range contact with one F atom of the PF counter-ion. Thallium(1) ethoxide has been found6' to cleave the ester of aspartane L-a-aspartyl-L-phenylalaninemethylester; a subsequent intramolecular cyclization gives T1'~3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine. The crystal structure shows that the T1' ions have four short and four long contacts to seven oxygen atoms and one nitrogen atom from a total of six neighbouring 3-benzyl-6-(carboxylatomethyl)-" L.M. Clarkson W. Clegg D. C. R. Hockless and N. C. Norman Acra Crystalloqr.,Sect. C 1992,48,236. 65 W. Hirpo S. Dhingra and M.G. Kanatzidis J. Chrm. Soc. Chem. Commun. 1992 557. " K. Aoki I.-H. Suh H. Nagashima J. Uzawa H. Yamazaki J. Am. Chem. Soc. 1992 114 5722. '' A. J. Blake G. Reid and M. Schroder J. Chem. Soc. Dalton Trans. 1992 2987. " P. Mikulcik P. Bissinger J. Riede H.Schmidbaur Z. Naturjorsch.. Tril B 1992. 47 952. J. P. Maher 2,5-dioxopiperazine anions. There are inter-anionic hydrogen bonds only between the imino groups and the carbonyl oxygen atoms a pattern similar to that found for cytosine-guanosine contacts in DNA. The 18-crown-6 complexes of thallium(1) 2- and 4-nitrophenoxide and of tcnq have been ~ynthesized.~~.~’ For the latter compound the TI+ lone pair has an active stereochemical role in the solid state. The new ternary phase TI3Al7S ,has been ~repared.~’ The polymeric anionic part of the structure can be described as a puckered layer-like arrangement of corner- sharing [AlS,]-tetrahedra parallel to the 001-plane. The aluminium-sulfur layers are connected via single sulfur atoms.These T1’ ions bridge the layers. The mean AI-S bond lengths are 2.227 8 for p2-S-Aland 2.298 A for p3-S-AI. The coordination of thallium is very asymmetric and the TI-S bond lengths vary from 3.009(9) to 3.907(9)& containing four short and two or three longer distances. A rather short TI. -T1 distance of 3.619(3) I$ is observed between two of the three crystallographically independent T1 atoms so that a weak bonding interaction is implied. The non-stoichiometric compound TI,Ti,Se has been found’ to crystallize in the hexagonal Nb,Se structure with TI atoms located in the hexagonal channels;72 the formal valence of the thallium atoms is clearly below + 1. The 2,2-dicyanoethylene- 1,l-diselenolate containing compound [AsPh,] ,[TI,- (Se,C=C(CN),),] has been prepared and characterized by single-crystal structure analysis.73 The complex is dimeric with a Se,Te octahedral centre and a TI-TI distance of 3.547(4) A.b9 L. R. Caswell J. E. Hardcastle T. A. Jordan I. Alam K.A. Mcdowell C.A. Mahan F. R. Fronczek and R.D. Gandour J. Inclus. Phenom. Mol. Recoyn. Chem.. 1992. 13. 31. ’O M.C. Grossel and S.C. Weston J. Chrm. Soc.. Chem. Commun.. 1992. 1510. ” B. Krebs and H. Greiwing. Z. Anorg. Allg. Chem. 1992. 616 145. ’’ W. Bensch and J. Koy Muter. Re.\. Bull.. 1992 27. 731. ” H.-U. Hummel. E. Fischer.T. Fischer. D.Gruss. A. Franke. and W. Dietzsch Chrm. Ber.. 1992,125 1565.

ISSN:0260-1818    

DOI:10.1039/IC9928900023

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

C Si Ge Sn and Pb By D. A. ARMITAGE Department of Chemistry King's College Strand London WC2R 2LS UK Fullerene research continues apace with about 1000 references in 1992 around twice that of 1991. Reviews cover personal reminiscences and perspectives' and the contributions of the various research groups are surveyed. Synthetic approaches toward molecular and polymeric carbon allotropes have been surveyed3 and a complete volume of both Accounts of Chemical Research4 and Carbon' devoted to aspects of fullerene chemistry. Brief summaries occured periodically in Nature6 and in Organometallic News7 as well as part of the ACS Symposium Series.* Australian semi-anthracite from the Yarrabee mine Queensland provides a useful source of fullerenes and once they have been separated using hexane and toluene mixtures the spent coal can be used for further purification of the C,o/C70 mixtures.Shungite from Shunga Karelia Russia comprises metamorphosed carbon-rich rock with meta-anthracite characteristics. Negative ion FTMS showed the presence of C, and C,,.9 Subjecting c6 to rapid non-hydrostatic compression of 20 GPa gives bulk polycrystalline diamond instantly at room temperature in contrast to the hydrostatic (anisotropic) compression which gave an insulating phase above 20 GPa.' The hot dense vapour produced by laser desorption of a fullerene film induces coalescence of fullerenes to give Con-(a = 2,3 n = 60; a = 2 n = 70).' ' Calculations support such a coalescence loss of C,. c60 and C, can be produced in ratios varying from 0.17 to 3.8 using laminar benzene/O,/argon flames and HPIX separation.Polycyclic aromatic hydrocarbons H. W. Kroto Angew. Chem. lnt. Ed. Enql. 1992 31 111 and J. Chem. Soc.. Dalton Trans. 1992 2141. R. M. Baum. Chem. Eng. News. 1992. June 1st. p. 25 H. Schwarz. Angew. Chem.. lnt. Ed. Engl.. 1992.31. 293. F. Diederich and Y. Rubin Angew. Chem. Inr. Ed. Engl.. 1992. 31. 1101. Acc. Chem. Res. 1992 25 No. 3. p. 97. Carbon 1992 30. No. 8 p. 1139. P. Ball Nature 1992,355 205; J. R. Heflin and A. F. Garito. ibid. 1992. 356 192; P. W. Stephens ihid.. 1992,356 383; L. F. Lindoy ihid.,1992. 357,443; M.S. Dresselhaus ihid. 1992. 358 195; H. W. Kroto ibid. 1992. 359 670. K. Itoh and H. Nagashima Organomet. News 1992. (I) 12; G. Matsubayashi. ibid..1992. (2). 80 (Chem. Ahsfr. 1992 117. 171 494c and 171 496e). P. J. Fagan J.C. Calabrese. and B. Malone ACS Symp. Ser.. 1992 481 177 (Chem. Absrr. 1992 116. 128 987h). M. A. Wilson L. S. K. Pang and A. M. Vassallo Nature. 1992,355,117; P. R. Buseck S.J. Tsipursky. and R. Hettich. Science. 1992 257 215. M. N. Regueiro. P. Monceau and J.-L. I-Iodeau. Nature. 1992 355 237. C. Yeretzian K. Hansen F. Diederich and R. L. Whetten Nururr 1992. 359. 44. 33 D. A. Armitage and oxides and higher fullerenes were also detected.' A plasma discharge reaction has been designed to produce gram quantities of fullerenes over an eight hour period,' while heating graphite to 2700°C in an atmosphere of He gives 10% fullerenes dominated by c6 and C70 (ratio 8 :3) but with some 7% comprising c84,c78,c82 c76 C90 c88 and (order of decreasing yield).l4 Extracts from the soot produced by the Kratschmer-Huffman technique suggests the presence of fullerenes with up to 330 carbon atoms but no nanotubes.15 Mechanisms have been suggested for both fullerene formation and photofragmentation. ' Methods of separation of C, and C, include recrystallization from toluene chromatography on alumina graphite and polystyrene gel or silica gel and a simple Soxhlet chromatographic separation.' Among the higher fullerenes chiral C, (0,symmetry) shows unusual electrochemi- cal properties. While c60 and C, readily undergo reversible reduction steps there is no reversible oxidation.I8 This is explained in terms of the six pyracyclene units in the structure each taking one electron to give 67c delocalization at one of the five-membered rings of this unit.C,, however exhibits both reversible reduction and oxidation due to the acene substructural units (a straight chain of at least three six-membered rings) which are absent in C60 and C7,. C, can be isolated as two distinct isomers in the ratio 5 1. They can be separated by HPLC and their 3C NMR spectra are consistent with C,,and D (chiral) structures respectively." The former can result from the D, isomer which possesses more structural strain through three flat coronene faces via a pyracyclene rearrangement first proposed by Stone and Wales (Equation 1). It appears that experimental conditions are crucial. A third isomer has also been characterized point group C2D, with ratio CZv,:C,, D as 5 :2 :2,' or 1 :6 2,2' depending on conditions.J. B. Howard J. T. McKinnon M. E. Johnson. Y. Makarovsky and A. L. Lafleur J. Phys. Chem. 1992,% 6657. l3 W. A. Scrivens and J. M. Tour. J. Org. Chem. 1992. 57 6932. l4 G. Peters and M. Jansen Angew. Chem. Int. Ed. Engl. 1992 31 223. l5 L. D. Lamb D. R. Huffman R. K. Workman S. Howells T. Chen D. Sarid and R. F. Ziolo Science 1992 255. 1413. l6 T.-M. Chang A. Naim. S.N. Ahmed G. Goodloe and P. B. Shevlin J. Am. Chem. Soc.. 1992 114,7603; R. L. DeMuro D.A. Jelski and T. F. George J. Phys. Chem. 1992 96 !0603. l7 N. Coustel P. Bernier R. Aznar A. Zahab J.-M. Lambert and P. Lyard J. Chem.Soc.. Chem. Commun. 1992 1402; P. Bhyrappa A. Penicaud M.Kawamoto and C. A. Reed ibid. 936; W. A. Scrivens P.V. Bedworth and J. M. Tour J. Am. Chem. Soc. 1992 114 7917; A.M. Vassallo A. J. Palmisano L. S. K. Pang and M. A. Wilson J. Chem. Soc. Chem. Commun.. 1992,60:A. Gugel M. Becker D. Hammel L. Mindach J. Rader T. Simon. M. Wagner and K. Mullen Angew. Chem. In?. Ed. Engl. 1992,31,644;A. Mittelbach W. Honk H. G. von Schnering J. Carlsen R. Janiak and H. Quast ibid. 1992,31,1640; K. C. Khemani M. Prato. and F. Wudl J. Org. Chem. 1992 57 3254. Is Q. Li F. Wudl. C. Thilgen. R. L. Whetten and F. Diederich J. Am. Chem. SOC. 1992 114 3994. '' F. Diederich R. L. Whetten C. Thilgen R. Ettl I. Chao and M. M. Alvarez Science 1991 254 1768. 2o K. Kikuchi. N. Nakahara T. Wakabayashi S. Suzuki H. Shiromaru Y. Miyake K. Saito I.Ikemoto M. Kainosho. and Y. Achiba Nature 1992 357 142. '*R. Taylor G.J. Langley. T.J.S. Dennis H. W Kroto and D.R.M. Walton J. Chem. Soc.. Chem. Commun. 1992 1043. C Si,Ge Sn and Pb 35 C, has nine isolated pentagon isomers and the 13C NMR spectra suggest a C isomer as the dominant one.,’ The 24 isomers of C84 that obey the isolated pentagon rule (IPR) fall into two disjoint families members of which can be interconverted by the pyracyclene transformation.22 The 3CNMR spectrum shows c84 to comprise two isomers one of each family with D,and D,,symmetry and in the ratio 2 l.20,23The molecular graph of fullerenes provides a method for predicting their point group I3C NMR spectral pattern and vibrational spectra.24 Stable fullerenes are thought to share the features of 12 isolated pentagons high delocalization energy and HOMO-LUMO gap and low strain energy.25 Further stabilization results if no five-membered ring contains a double bond and the number of benzenoid rings is a maximum as can be predicted by leap-frog carbon clusters C (n = 60 + 6k,k > 1) which have closed-shell electronic structures.26 These rules can be extended to include fulleroid carbon cylinders -which possess terminal heptagonal octagonal and nonagonal rings of atoms at the poles and so are not strictly fullerenes., Magic numbers for stable structures have been predicted for fullerenes and their doubly-charged derivatives.Anions have two carbon atoms less than the stable neutral cluster and the cations two carbon atoms more.28 The experimental enthalpy of formation of crystalline C, has been determined as 2422 and 2278 kJ mol-’ by two research groups.29 C, shows orientation disorder in the low temperature modification and isomers of C, with pentagonal rings adjacent are predicted to be 1-2eV higher in energy than the I is0mer.j’ The vibrational frequencies of 13C, have been predi~ted.~’ The ‘rugby ball’ structure of C, (falmerene) is confirmed by electron diffraction and shows the slight pinching at the waist.The bonds within the pentagons are 146-147pm and the rest 137-139~m.~~ Powder X-ray diffraction shows sublimed C, to comprise small quantities of a second HCP form as well as FCC phase both of which slowly transform to the dominating HCP form on annealing.33 The endohedral derivative He@lC& results from bombarding helium with highly accelerated moiecular beams of C& and both cations can be reduced to the neutral species by Me,N.34 Further support for inclusion in the 7 8 cavity of C, comes from similar insertion through bombardment using first 3He then 4He.35 Both are inserted 22 P.W. Fowler D. E. Manolopoulos and R. P. Ryan J. Chem. Soc. Chem. Commun. 1992 408. ” D. E. Manolopoulos P. W. Fowler. R. Taylor. H. W. Kroto,and D. R. M. Walton. J. Chem. Soc.,Furuduy Trans. 1992 88 3117. 24 D. E. Manolopoulos and P. W. Fowler. J. Chem. Phys. 1992. 96 7603. 25 R. Taylor J. Chem. Soc. Perkin Trans. ;I 1992 3. ” P.W. Fowler J. Chem. Soc. Perkin Trany. 2 1992. 145 D. E. Manolopoulos D. R. Woodall and P.W. Fowler J. Chem. Soc. Faraday Trans. 1992 88. 2427. ’’ P. W. Fowler and V. Morvan J. Chem. Soc. Furaday Trans. 1992. 88 2631. 28 P. W. Fowler and D. E. Manolopoulos Nature 1992 355 428. 29 W. V. Steele R. D. Chirico N. K. Smith W. E. Billups P. R. Elmore and A. E. Wheeler J. Phys. Chem.. 1992 96 4731; H.-D. Beckhaus. C. Ruchardt M. Kao F. Diederich and C.S. Foote Angew. Chem. Int. Ed. Enyl. 1992 31 63. ’() H.-B. Burgi E. Blanc. D. Schwartzenbach S. Liu Y.-j. Lu. M. M. Kappes and J.A. Ibers. Angew. Chem. Int. Ed. Engl. 1992,31,640; K. Raghavachari and C. M. Rohlfing J. Phys. Chem. 1992. 96 2463. 31 B. N. Cyvin E. Brendsdal J. Brunvoll and S.J. Cyvin Spectrochim. Actu A 1992 48 1355. 32 D. R. McKenzie C. A. Davis D.J. H. Cockayne D. A. Muller.and A. M. Vassallo. Nature 1992,355,622. 33 M.A. Green M. Kurmoo P. Day and K.Kikuchi J. Chem. Soc. Chem. Commun. 1992 1676. 34 T. Weiske T. Wong W. Kratschmer J. K Terlouw and H. Schwarz Angew. Chem.. Int. Ed. Engl.. 1992. 31 183. 35 T. Weiske and H. Schwarz. Anyew. Chem.. lnt. Ed. Engl. 1992 31 605. 36 D.A. Armitage to give a MS peak at 727 along with smaller odd ones formed from loss of up to four C2 units. Helium will also insert in the C;o cluster and neon 8 keV Clo calculations indicating chaotic motion of Ne in the neutral C, cage.36 Positive muons (p+)will bind an electron to form a muonium atom (Mu = p’e-) of mass about 11YOthat of hydrogen. Because of its easy encapsulation in fullerenes muonium can act as a microscopic probe.In C70 an axially symmetric hyperfine interaction is present and a small 2p admixture in the ground state wave function of Mu@C7 enables the internal shape to be reproduced including the ‘pinching’ at the equator. The ESR spectra suggest the formation of two isomers of M@C82 (M = Sc Y La) prepared from M20 and graphite with one dominating for each metal proposed to be the C isomer of the four postulated for C8,.38 There is space available for more than one metal atom and evidence supports the formation of sc3@c8239 and Y2@C82,40 and for M2@C80,41 where M is a rare earth metal. However YC82 through time-of-flight mass spectrometry and examined by extended X-ray absorption fine structure appears to have an exohedral structure such as c82YcYc82 in view of the coordination number and Y-C bond distances.42 However strong evidence supports the encapsulation of lanthanum into the c82 fullerene.The Stone-Wales pyracyclene transformation allows the interconversion of all nine isolated pentagon fullerene isomers of c82 and Hiickel arguments predict a C, structure for C’,, but a C structure for C”,. EPR and XPS studies support the latter structure though arguments do support a C,,structure with La3+ in a low symmetry high coordination number site with the unpaired electron del~calized.~~ Laser vaporization of graphite-UO gave uranium encapsulation with U@c28 as the most abundant species. The uranium shows no tendancy to oxdize and has a 4f binding energy only about 0.5 eV greater than that of the uranium metal.It has orbitals compatible with those within the cage.44 Zirconium dioxide gives a similar compound. The anions Cz; and C:; have been detected electrochemically the former with LUMOs t, and t, and the latter el” and a;l for the neutral cage.45 0 affects the EPR signal of the Ck radical4 and there is evidence of a dynamic Jahn-Teller effect in 36 T. Weiske J. Hrusak D. K. Bohme and H. Schwarz Helc. Chim. Acta 1992 75 79; A.L.R. Bug A. Wilson and G.A. Voth J. Phys. Chem. 1992. 96 7864. 37 K. Prassides T. J. S. Dennis C. Christides E. Roduner H. W. Kroto R. Taylor and D. R. M. Walton J. Phys. Chem. 1992 96 10600. S. Suzuki S. Kawata H. Shiromaru K. Yamauchi K. Kikuchi. T. Kato and Y. Achiba J. Phys. Chem. 1992,% 7159; D. E. Manolopoulos P. W. Fowler and R.P. Ryan J. Chem. Soc. Faraday Trans.. 1992 88 1225. 39 H. Shinohara H. Sato M. Ohkohchi. Y. Ando T. Kodama T. Shida,T. Kato and Y. Saito Nature. 1992 357 52. 40 H. Shinohara H. Sato Y. Saito. M. Ohkohchi and Y. Ando J. Phys. Chem. 1992. 96 3571. 4’ E.G. Gillan C. Yeretzian K. S. Min. M. M. Alvarez. R. L. Whetten and R. B. Kaner J. Phys. Chem. 1992 96 6869; M. M. Ross H. H. Nelson J. H. Callahan and S. W. McElvany ihid. 1992 96 5231. 42 L. Soderholm P. Wurz K.R. Lykke D.H. Parker and F. W. Lytle. J. Phys. Chem. 1992 96 7153. 43 R.D. Johnson M.S. de Vries. J. Salem D. S. Bethune and C. S. Yannoni. Nature 1992 355 239; K. Laasonen W. Andreoni and M. Parrinello Science. 1992 258. 1916. 44 T. Guo. M. D. Diener. Y. Chai M. J. Alford R. E. Haufler S.M. McClure T. Ohno. J. H. Weaver G.E. Scuseria and R. E. Srnalley Science. 1992 257. 1661. 45 Y. Ohsawa and T. Saji. J. Chem. Soc. Chem. Commun. 1992 781; Q. Xie. E. Perez-Cordero. and L. Echegoyen J. Am. Chem. Soc.. 1992. 114. 3978 F. Negri. G. Orlandi and F. Zerbetto ihid.. 1992. 114 2909. 46 M. D. Pace. T.C. Christidis J.J. Yin and J. Milliken J. Phys. Chem.. 1992 96 6855; S. Kawata K. Yamauchi S. Suzuki K. Kikuchi H. Shirornaru M. Katada. K. Saito. I. Ikemoto. and Y. Achiba Chem. Lett. 1992 1659. C Si Ge Sn and Pb triplet C60.47 Photoexcited porphyrin undergoes electron transfer with both ground state and excited C, and C,0,48 and a range of electrochemical reductions of both fullerenes has been reported.49 Doping c60 with alkaline earth metals gives supercon- ducting fullerides with Ca,C, superconducting below 8.4K and Ba,C,o below 7 K,,' showing occupation oft, as well as t, of C,,.,l Pure 13C, depresses T for K3C, by 0.45 K from the value for 12C6, and Rb3C, behaves similarly.52 Radicals add to C, at the bond between two six-membered rings (6 6) with the electron confined mostly to this bond giving two coupled cyclohexadienyl radicals.These radicals exist in equilibrium with dimers RC,,C,,R if R is relatively bulky. Thus dimerization is thought to occur through the positions para to where R is ~ubstituted.,~ There is no evidence for radical stability if R is small. The racial Bu'C; results as a mixture of three isomers the dominant one involving attack at a carbon atom of the polar five-membered ring with the other two at the two types of carbon adjacent to or on the Addition of Bu'Li to c60 gave Ru'C;,.Protonation is thought to occur at the para position in the substituted ring as is hydrogenation of the radical by Bu;SnH. Isomerization to the ortho-isomer occurs thereby removing the double bond from the five-membered ring (Equation 2). This reaction and that involving the less reactive EtMgBr to give C,,EtH has been used as a method coupled with HPLC for titrating c,,? Diazomethane gives an unstable adduct with c60 that decomposes to C61H2 in which CH bridges a 6 5 bond.56 Using 0-benzyl or 0-pivaloyl protected monosac- charide spiro-diazirines c60 gives the spiro 'adduct' thereby providing the first chiral 47 G.L. Closs P. Gautam D. Zhang P. J Krusic S.A. Hill and E. Wasserman. J. Phys. Chern. 1992. 96. 5228; H. Levanon V. Meiklyar. A. Michaeli and A. Regev J. Phys. Chem. 1992 96 6128. 4H K.C. Hwang and D. Mauzerall J. Am. Chem. Soc. 1992 114. 9505. 49 F. Zhou S.-L. Yau C. Jehoulet D. A. Laude Jr. Z. Guan and A. J. Bard. J. Phys. Chem.,1992.96,4160; D. Dubois. G. Moninot. W. Kutner M. T.Jones and K. M. Kadish. ihid. 1992,96,7137; D. Dubois M. T. Jones and K. M. Kadish J. Am. Cheni. Soc,.. 1992 114 6446; G.A. Heath J. E. McGrady and R. L. Martin J. Chem. Soc.. Chem. Commun. 1992 1272; D. R. Lawson D. L. Feldheim C.A. Foss P. K. Dorhout C. M. Elliot C. R. Martin. and B. Parkinson J. Phys. Chem. 1992 96 7175. SO A. R. Kortan N. Kopylov S. Glarum. E. M. Gyorgy A.P. Ramirez. R. M. Fleming F. A. Thiel. and R. C. Haddon Nature 1992. 355 529; A. R. Kortan N. Kopylov S. Glarum E. M. Gyorgy. A. P. Ramirez R. M. Fleming 0.Zhou F.A. Thiel P. L. Trevor and R.C. Haddon. ihid. 1992 360. 566. 41 R.C. Haddon G. P. Kochanski A. F. Hebard A.T. Fiory and R.C. Morris Science. 1992. 258; 1636; G. K. Wertheim D.N. E. Buchanan and J.E. Rowe. ihid.. 1992 258. 1638. 52 C.-C. Chen and C. M. Lieber,J. Am. Chrm. So(..,1992.114,3141;T. W. Ebbesen J. S. Tsai K. Tanigaki. J. Tabuchi Y. Shimakawa Y. Kubo I. Hirosawa and J. Mizuki Nature 1992. 355 620. 53 J. R. Morton K. F. Preston P. J. Krusic. S.A. Hill and E. Wasserman.J. Phys. Chem..1992.96.3576; J. R. Morton. K. F. Preston. P. J. Krusic. and E. Wasserman J. Chem. Soc..Prrkin Truns. 2 1992. 1425; J. R. Morton K. F. Preston P. J. Krusic S. A. Hill. and E. Wasserman. J. Am. Chem. Soc. 1992. 114. 5454. 54 P. N. Keizer. J. R. Morton and K. F. Preston. J. Chern. Soc. Chem. Cornmun.. 1992. 1259. 5s P. J. Fagan P. J. Krusic D. H. Evans S. A. Lerke. and E. Johnston. J. Am. Chem.SOL..,1992114,9697; A. Hirsch A. Soi. and H. R. Karfunkel. Anqew. Chem. [nt. Ed. Enyl.. 1992. 31. 766. 56 T. Suzuki Q. 'Chan' Li K.C. Khemani. and F. Wudl. J. Am. Chem. Soc,.. 1992. 114 7301. 38 D. A. Armitage and enantiomerically pure fullerene deri~ative.~' Up to six Ph,C residues will add to c60 across the 6:6 bonds NMR evidence supporting the formation of a diphenyl- methano[ IOlannulene structure. Such addition with appropriately functionalized aryl groups provides for polymer synthesis while PhC(N,)C,H,C(N,)Ph enables two C, units to be coupled to provide the units of 'pearl necklace' polymers.58 Benzyne adds to c60 to give C,o(C,H,) (n= 14) with C,,C,H being the best characterized,additionoccurringacross the6 :6 bond.59 Electrophilicphenylationgives C,,Ph, as the major product though C,,Ph and mono and dioxides are also formed.,' Paraxyxylene and C, copolymerize under free radical conditions at 650 T.The dications of C, and C,, and their radical mono cations readily react with atomic hydrogen and C; shows a near-IR absorption at 973nrn., C: with ammonia gives a series of solvated amides C,,NH,(NH3)J (n = 0-3) in which the NH group is thought to bridge a 6 5bond.63 Methylamines give the radical cations of both amine and c60 whereas coulombic adducts form with unsaturated hydrocar- bon~.,~ While CO gives two IR bands when absorbed on c,, indicating two absorption sites NO shows a multiplet between the two NO bands suggesting absorption as the dime^-.,^ Bombarding C, with C' gives Ci which decomposes to C; and C while N+ gives C and N.At high energy C19 and C,,N+ were detected., C, reacts with NO,' to give C,,(NO,+) which with nucleophiles such as carboxylates or water leads to mixed hydroxybenzoates. These with alkali give water-soluble fullerols with up to 20 hydroxyl groups per cage. They cannot be prepared directly from KOH and C, as addition is reversible and 0 sensitive.,' Reaction of c60 with dimethyldioxirane yields the 1,3-dioxolane adduct as a yellow solution through addition across the 6 :6 bond.The epoxide (purple solution) also results though not directly from the dioxolane; it is however formed by the photolytic oxidation of C, in benzene.,' C,,O has the same lattice symmetry FCC as C, at room temperature and the lattice parameters are only 2 pm (0.1O/O) greater than those of C,,. The oxygen atoms occupy vacant octahedral interstitial sites.,' '' A. Vasella. P. Uhlmann C.A. A. Waldraff. E. Diederich and C. Thilgen. Anyew. Chem.. Inr. Ed. Enyl. 1992. 31 1388. '' T. Suziki. Q. Li K.C. Khernani F. Wudl. and 0.Alrnarsson J. Am. Chrm. Soc. 1992 114 7300 S. Shi K. X. C. Khernani Q. Than' Li. and F. Wudl. ihid.. 1992. 114. 10656. '' S. H. Hoke. 11. J. Molstad D.Dilettato M. J. Jay D. Carlson. B. Kahr. and R. G. Cooks. J. Org. Chem.. 1992 57 5069. 60 R. Taylor G. J. Langley. M. F. Meidine J. P. Parsons A. K. Abdul-Sada T. J. Dennis J. P. Hare H. W. Kroto. and D. R. M. Walton. J. Chem. Soc.. Chem. Commun.. 1992. 667. 61 D.A. Loy and R. A. Assink. J. Am. Cheni. Soc.. 1992 114. 3977. 62 S. Petrie G. Javahery J. Wang. and D. K. Bohme. J. Am. Chrm. Soc. 1992. 114 6268; Z. Gasyna. L. Andrews. and P. N. Schatz J. Phvs. Chrm. 1992,96 1525; S. Nonell. J. W. Arbogast and C.S. Foote J. Phys. Chem. 1992 96 4169. 63 J.J. Stry. M.T. Coolbaugh. E. Turos. and J. F. Garvey J. Am. Chrm. Soc. 1992. 96.7914. 64 S. Petrie G.Javahery. J. Wang. and D.K. Bohrne. J. Am. Chrm. Soc.. 1992 114 9177; idem.. J. Phys. Chem..1992. 96,6121. 65 M. Fastow Y. Kozirovski M. Folman. and J. Heidberg. J. Phys. Chum. 1992 96.6126. " J. F. Christian Z. Wan and S. L. Anderson J. Phys. Chem.. 1992,96 3514 and 10597. " L. Y. Chiang. R. B. Upasani and J. W. Swirczewski. J. Am. Chem. Soc. 1992. 114. 10 154; L. Y. Chiang. J. W. Swirczewski C. S. Hsu. S.K. Chowdhury. S. Cameron. and K. Creegan J. Chern. Soc,.. Chrm. Commun. 1992 1791; A. Naim and P. B. Shevlin. Tetrahedron Lett. 1992. 33 7097. " Y. Elernes. S. K. Silverman C. Sheu. M. Kao C.S. Foote M.M. Alvarez and R. L. Whetten Angrw. Chrm.. Int. Ed. Engl. 1992.31. 351;K. M. Kreegan. J. L. Robbins. W. K. Robbins. J. M. Millar R. D. Sherwood P. J. Tindall D. M. Cox. A. B. Smith Ill J. P. McCauley Jr.. D. R. Jones. and R.T. Gallagher J.Am. Chern. Soc,.. 1992. 114. 1103. " A. Cheng and M. L. Klein. J. <'hem. Soc,.. Furuduy Truns. 1992. 88. 1949. C Si,Ge Sn and Pb Fluorinated c60 reacts readily with Na,CO, and slowly hydrolyses with HF release reactivity increasing with the degree of fl~orination.~' Many other nuc- leophiles react similarly including organic anions complexed hydrides methoxide and amines.,l Fluorination of C, and C, gives up to 80% addition.72 Bromination of c60 in solution gives C,,Br6 (l) (magenta plates) and C,,Br (2) (dark brown prisms). Compound (1) has a structure involving one brominated pentagon with a long C-Br bond of 203 pm itself adjacent to five other brominated pentagons (C-Br 196pm). It disporportionates on warming to give C, and (2),which has a C, structure with pairs of bromine atoms arranged meta on four six-membered rings.73 C,,Br, results from C, and liquid bromine and has Thsymmetry with twelve hexagons disubstituted para and in pairs with boat conformations but mutually meta on the other eight hexagons which have a chair conformation (3).Such symmetry predicts three IR active bands observed at 604,546 and 527 cm -' and shows 18C=C double bonds arranged one per pentagon and one at each 6 :6 bond. All these bromides contain intercalated bromine and completely debrominate on heating.74 Iodine forms an intercalated product with c60 but there is no evidence of addition.75 A range of intercalation products for C, results with benzene and ferr~cene,~ the latter like the tetrathia and tell~rafulvalene~~ and tetrakis(dimethy1amino)ethene derivative^,^^ shows charge transfer to c60.c60 behaves chemically as an electron-poor species. The electrochemical reduction 7 0 R. Taylor A.G. Avent. T. J. Dennis J. P. Hare H. W. Kroto. D. R. M. Walton J. H. Holloway E.G. Hope and G.J. Langley Nature 1992 355,2. 71 R. Taylor J. H. Holloway. E. G. Hope A.G. Avent G.J. Langley T.J. Dennis J. P. Hare. H. W. Kroto and D. R. M. Walton J. Chem. Soc. Chem. Commun. 1992 665. 12 A. A. Tuinman P. Mukherjee J. L. Adcock R. L. Hettich and R. N. Compton J. Phys. Chern. 1992,96. 7584. 73 P. R. Birkett P. B. Hitchcock H. W. Kroto R. Taylor. and D. R. M. Walton. Nature 1992 357.479. 14 F. N.Tebbe R. L. Harlow D. B. Chase. I). L. Thorn,G.C. Campbell.Jr.. J.C. Calabrese N. Herron. R. J. Young Jr. and E. Wasserman. Science 1992. 256,822. 15 Q. Zhu D.E. Cox J.E. Fischer. K. Kniaz A. R. McGhie and 0.Zhou Nature 1992 355,712; T.R. Ohno G.H. Kroll J.H. Weaver L. P. F. Chibante and R. E. Smalley ihid.. 1992 355,401. 76 M. F.Meidine P. B. Hitchcock H. W. Kroto R. Taylor and D. R. M. Walton J. Chem. Soc. Chem. Commun. 1992 1534; J. D. Crane P. B. Hitchcock. H. W. Kroto. R. Taylor and D. R. M. Walton ihid. 1992 1764. 71 A. Izuoka T. Tachikawa T. Sugawara Y. Suzuki. M. Konno Y. Saito and H. Shinohara J. Chern. SOC. Chem.Comrnun. 1992 1472; A. Izuoka T. Tachikawa. T. Sugawara Y. Saito. and H. Shinohara Chem. Lett. 1992,1049;T. Pradeep K. K. Singh,A. P. B. Sinha.and D. E. Morris J. Chem.Soc.. Chem. Commun.1992. 1747. 78 P. W. Stephens D. Cox J. W. Lauher. L. Mihaly J. B. Wiley P.-M. Allemand. A. Hirsch. K. Holczer. Q. Li J. D. Thompson and F. Wudl. Nature. 1992. 355.331; Y. Wang Nature 1992 356.585. D. A. Armitage of phosphine substituted nickel group complexes shows the metal to decrease the electron affinity of C, by raising the energy of the LUMO due to removal of one conjugated double bond. This effect increases with the degree of substitution in a linear manner.79 The dibenzylidene-acetone ligand is readily replaced on Pd by c60 to give air-stable C,,Pd as a one-dimensional linear polymer. This on refluxing in toluene quickly gives C,,Pd (2D) then slowly C,,Pd (3D).The latter readily catalyses the hydrogenation of olefins and acetylenes.80 The compound ‘15-C9H,Ir(CO)(r12-C60) gives a triplet species on laser irradiation since it readily transfers its energy to 0,.81 The complex (PhCH,OC,H,CH,- PPh,)21r(CO)Cl(~2-C,,) crystallizes with both benzyloxyphenyl groups clasping the adjacent c60unit to give a linear polymer.82 Reacting excess Ir(CO)Cl(PPhMe,) with C, gives the disubstituted complex the two Ir atoms occupying double bonds near opposite poles and adjacent to the polar five-membered rings.This results in 60% yield indicating distinction between the double bonds of C,,.83 Bisosmylation of C,, however gives a mixture of five products and with initial addition to a 6 :6 bond the second osmylation occurs at the five such positions not sterically close to that already substit~ted.~~ Calculations predict that C,,H would be formed exothermically from C, and H or alkanes if substituted ortho or para at a six-membered ring.85 The addition should become more exothermic with increasing substitution for alkanes and perchloroal- kanes but not for perfluoroalkanes.Exothermicity decreases with increasing size of the halogen and para substitution becomes more stable relative to ortho with size.86 Both ortho and para substitution of six-membered rings of C, is also anticipated and if the five types of carbon atom are labelled e(equator),l,2,3,N(northpole) then 2/2 and N/3 ortho derivatives are predicted to be the more stable together with para addition at equatorial and polar hexagon^.^ As all stable fullerenes contain the C, decacyclene unit (4),it is suggested that addition reactions that still maintain this unit will be 79 S.A. Lerke 9. A. Parkinson D. H. Evans and P. J. Fagan. J. Am. Chrm. Sot.. 1992 114 7807. no H. Nagashima,A. Nakaoka Y. Saito. M. Kato,T. KawanishLand K. Itoh J. Chem. Soc.. Chem. Commun.. 1992 377; H. Nagashima. A. Nakaoka S. Tajima Y. Saito and K. Itoh Chem. Lett. 1992 1361. 81 Y. Zhu R.S. Koefod C. Devadoss J. R. Shapley and G.9. Schuster Inorg. Chem. 1992 31 3505. 82 A. L. Balch V. V. Catalano J. W. Lee and M. M. Olmstead J. Am. Chem. Soc. 1992 114. 5455. 83 A. L. Balch J. W. Lee and M. M. Olmstead. Angrw. Chem.. Int. Ed. Engl. 1992. 31. 1356. 84 J. M. Hawkins A. Meyer T. A. Lewis. U. Bunz R. Nunlist. G. E. Ball T. W. Ebbesen. and K. Tanigaki,J. Am.Chem. Sot.. 1992 114. 7954. 85 N. Matsuzawa D. A. Dixon and T. Fukunaga J. Phys. Chrm. 1992 96. 7594. 86 D.A. Dixon N. Matsuzawa. T. Fukunaga. and F.N. Tebbe J. Phys. Chem.. 1992 96. 6107; N. Matsuzawa T. Fukunaga and D.A. Dixon J. Phys. Chem. 1992 96. 10747. 87 H. R. Karfunkel and A. Hirsch. Anyebv. Chem. Int. Ed. Engl. 1992 31. 1468. C Si Ge Sn and Ph 41 favoured. With higher fullerenes the presence of two decacyclene units is possible and in C78 both C, and D, structures interconvertible through the pyracyclene transformation should form C7,X through addition to the three C multiply-bonded units outside the two decacyclene units. Such addition should not occur with the D isomer., Optimized conditions for maximum yields of nanotubes are 18V d.c.at 500tor under He but calculations indicate that the nanotubes are higher in energy per carbon atom than their spherical isomer^.^' The compound C12B1,N2, with s6 symmetry should be stable and a suggested synthesis involves pyrolysis of boron-nitrogen analogues of naphthalene with alternating B N and C atoms in the ratio 2 2 1 and substituted to encourage conden~ation.’~ Calculations indicate C ,B2,N24 to be more stable than C,, itself slightly more stable than B,,N,o.~~ The mass spectra of products formed from the gas-phase reaction of titanium with CH, C,H, C,H, C,H, and C,H all show a dominant peak corresponding to Ti,C:,. This cage is thought to possess a pentagonal dodecahedral structure (Th) with fused five-membered rings containing two titanium and three carbon atoms each Ti bonding to three carbon atoms.Similar peaks are observed for Zr Hf and V the latter also taking up ND at each vanadium site.92 The structure is thought to be built from small units such as Ti,C,. With the heavier metals e.g. Zr Ta fused multicages are also formed with up to four dodecahedral units through face fusion. No hexagons are formed in contrast to the expansion of the C, structure.’ The stability of the Ti,C, structure is a result of stronger bonding between Ti and C than in TIC incorporating weak metal-carbon d,-p,-interactions and strong C=C n-bonding. As the metals connect six C=C bonds through a-bonds M,C, clusters will be less stable for transition metals with more than five valence electrons.Also a Jahn-Teller distortion would be predicted for T symmetry but not if distorted to D, or D,,. Similar calculations also support high stability for Si,Cl 2.94 The structure and reactivity of silicon clusters show Sinwith n = 21 25 33 39 and 45 to be particularly unreactive while Si, is predicted to have a structure resembling a stack of six planar bicyclic (silanaphthalene) units with all but the upper and lower stacks involving four coordinate silicon.95 Reductively coupling Me,CHCMe,SiCl with sodium gives the octasilacubane in 2.6% yield as a red-orange air-stable crystalline solid. The structure is distorted from an idealized cube with Si-Si and C-C bonds longer than normal due to the strained Si framework; a UV absorption at 500 nm the longest reported for any polysilane that nx R.Taylor J. Chem. Soc. Perkin Trans. 2. 1992 1667. 89 T. W. Ebbesen and P. M. Ajayan Nuture 1992 358 220; G. B. Adams 0.F. Sankey. J.B. Page M. O’Keeffe and D. A. Drabold Science 1992 256. 1792. 90 J. R. Bowser D.A. Jelski and T. F. George Inorg. Chem. 1992 31. 154. ’’ X. Xia D.A. Jelski J. R. Bowser and T. F. George J. Am. Chem. Soc. 1992. 114 6493. ’’ B. C. Guo K. P. Kerns and A. W. Castleman Jr.. Science. 1992,255. 141 1 B. C.Guo S.Wei J. Purnell. S. Buzza and A. W. Castleman Jr. ihid. 1992 256 515. 93 S. Wei B. C. Guo J. Purnell. S. Buzza and A. W. Castleman. Jr. J. Phys. Chem. 1992. 96 4166; idem.. Science 1992 256 818. 94 B. V. Reddy S. N. Khanna and P. Jena Science 1992.258.1640; Z. Lin and M. B. Hall J.Am. Chem.Soc.. 1992,114 10054; A. Ceulemans and P.W. Fowler J. Chem. Soc. Faradag Trans. 1992,88,2797; M.-M. Rohmer P. de Vaal and M. Benard J. Am. Chem. Soc. 1992.114,9696 R. W. Grimes and J. D. Gale J. Chem. Soc.. Chem. Commun. 1992 1222. 95 T. Lange and T. P. Martin Angew. Chem. Int. Ed. Engl. 1992 31. 172 S. Li R. L. Johnston and J. N. Murrell. J. Chem. Soc. Faraday Trans.. 1992.88 1229; C. Zybill. Angew. Chern. Int. Ed. EnqI. 1992 31 173. 42 D. A. Armitage accounts for the c~lour.~~ The 2,6-diethylphenyl analogue can be prepared similarly and has rather shorter Si-Si bonds and is yellow-orange in colour. The germanium substituted cubane (Et,MeCGe) results in 3% yield directly from the trichloride or in 16% yield from [Et,MeC(Cl)Ge] using Mg/MgBr as reducing agent.97 Treating IsMgBr with SnCl gives the cyclotristannane (Is,Sn) which dissociates in solution to give the stannylene and distannene (Is = 2,4,6-Pr\C6H2).Typically it adds phenylacetylene to give the 1,2-di~tannacyclobutene.~~ Reducing [(2,6-diethyl-phenyl),Sn] with excess lithium gives the propellene (5)in 31YOyield along with about 1Yo of octakis(2,6-diethylphenyl)tetracyclo[4.1 .O.O' .s.02q6]heptastannane (6).Less lithium gives the cyclotetrastannane (7) as intermediate (Scheme 1).99 IS2 Is2 1% '"A '"L Si 2.3Li Sn Sn / \ Is 1.2Li ([s2sn13 - s:-- /,I/ I Is3SnH + Is2Sn\ /SnH c- /,A Sn + Sn--=Sn I Sn NH4C1 NH4C1 /,I I c- In Sn Sn Sn IsSn SnIs ' Is2 Is2 Is2 ' / 1 I%Sn-SnIs2 n-SnIs2 (7) (5) (6) Scheme 1 Laser flash photolysis of the cyclotetragermane PrgGe gives germylene extrusion and dimerization to the digermene together with the cyclotrigermane.O0 (BuiGe) inserts phenyl isocyanide to give the trigermabutanimine and sulfur selenium and tellurium all insert to give the chalcotrigermetane with a planar structure found for selenium and tellurium.'01 The hindered cyclotrisilane (BuiSi) also reacts with aryl isocyanides through ring insertion subsequent photolysis results in isobutene loss to give (8) and (9).lo2 If the isocyanide is electron-withdrawing for example with CF,N=C then further insertion occurs to give the 1,3-disilacyclobutane (10) (Scheme 2).'03 Thermolysing Mes,Ge (Ge-Ge 253.8 pm) with Et,SiH gives the silylgermane through insertion of germylene into the Si-H bond and the silyldigermane by insertion of Mes,Ge(Mes)Ge formed through rearrangement of Mes,Ge=GeMes,.' O4 The siladigermirane Mes,SiGe loses germylene on pyrolysis to give the silylgermane with Et,SiH and the germasilene rearranges to the silylgermylene which also inserts Et,SiH.' OS The structures of the isomers of Me,MM'Ph (M,M' = Si or Ge) show different 96 H.Matsumoto K. Higuchi S. Kyushin and M. Goto Angew. Chem. Int. Ed. Eng/. 1992. 31 1354. 97 A. Sekiguchi T. Yatabe H. Kamatani C. Kabuto and H. Sakurai. J. Am. Chem. SOC. 1992 114 6260. 98 M. Weidenbruch A. Schaefer H. Kilian. S. Pohl W. Saak and H. Marsmann Chem. Ber. 1992,125,563. 99 L. R. Sita and I. Kinoshita J.Am. Chem. SOC..1992 114 7024. 100 K. Mochida and S. Tokura Organomera//ics,1992 11 2752. 101 M. Weidenbruch A. Ritschl K. Peters and H. G. von Schnering J. Orgunomrt. Chem. 1992,438,39 and 1992 437 C25. 102 M. Weidenbruch J. Hamann S. Pohl and W. Saak Chem. Ber. 1992. 125 1043; M. Weidenbruch J. Hamann K. Peters H.G. von Schnering and H. Marsmann J. Organomet. Chem. 1992 441 185. 103 M. Weidenbruch J. Hamann H. Piel D. Lentz K. Peters. and H. G. von Schnering J. Organomet.Chem. 1992 426. 35. I04 K. M. Baines J. A. Cooke and J. J. Vittal J. Chem. Soc. Chem. Commun.. 1992 1484. 105 K. M. Baines and J. A. Cooke Organornetal/ics 1992 11 3487. 43 C Si,Ge Sn and Ph I Si-SiK2 hv * + I :YNAr !vNAr Ar = naphlhyl RSi-SiR2 R2 H (9) Scheme 2 Ge-Sn bond lengths Me,GeSnPh (259.9pm) and Ph,GeSnMe (265.2pm).The expansion of the orbitals of Ge in the Me,Ge group through the electron donating methyl groups and contraction of those of Ph,Sn through the electron attracting phenyl groups makes overlap better in the former compound."" The disilenes Is(R)Si=Si(R)Is (R = But SiMe,) result from Is(R)Si(SiMe,) on photolysis as a mixture of isomers but heating converts the cis to trans.'07 (Me,Si),SiH is an increasingly important silyl radical source and its lithium derivative (1l) prepared from (Me,Si),Si and MeLi reacts with adamantanone to give a bridgehead silene which spontaneously dimerizes. The product has long C-C and C-Si bonds reflecting the hindrance (Equation 3).'OS Compound (1 1) can also be coupled using PbCl to give the octasilane (Me,Si),SiSi(SiMe,) in which the central Si-Si bond of 240.3pm is longer than the rest by some 3 pm.lo9 TsiLi and Ga,Br give the tetrahedral cluster (TsiGa) which is stable to heat and oxygen and possesses a tetrahedral arrangement of Ga atoms.' lo The trihalides TsiSiX (X = C1 Br) show low temperature NMR spectra indicating three peaks of equal intensity.This is consistent with the three methyl groups of the Me,Si group being inequivalent.' '' Photolysing (Me,Si),Si(Mes)COAd gives a mixture of silene geometric isomers stable in solution at room temperature. Addition reactions with I Ob K. H. Pannell L. Parkanyi H. Sharma. and F. Cervantes-Lee Inorg. Chem. 1992 31. 522. '07 R.S. Archibald Y. van den Winkel A. J. Millevolte J. M. Desper and R. West Organometallics 1992 11. 3216. 'OH D. Bravo-Zhivotovskii,V. Braude. A. Stanger. M. Kapon and Y. Apeloig Uryanornerallics 1992.11,2326. S. P. Mallela 1. Bernal and R.A. Geanangel Inorg. Chem.. 1992 31 1626. ''O W. Uhl W. Hiller M. Layh and W. Schwarz Angew. Chem. Inr. Ed. Engl. 1992 31 1364. 'I1 A.G. Avent. S.G. Bott J. A Ladd. P. D. Lickiss and A.D. Pidcock J. Organomet. Chem. 1992,427.9. 44 D. A. Armitage PhC-CH is highly stereospecific and methanol gives a diastereomeric pair of adducts.' '' The stable germenes Mes,Ge=CRR' (R,R'=H,CH,Bu' or fluorenylidene) readily add both electrophiles and nucleophiles.' ' The fluorenylidenestannene substituted with Is groups at tin can also be prepared as an ether adduct.'' Stannocene reacts with C,H,Na in the presence of PMDETA to give a complexed adduct in which one C,H group is sandwiched between tin and sodium.' ' Lithiated 2,5-di-t-butylpyrrole reacts with both SnCI and PbCl to give the heterostannocene and plumbocene.' The stannylene [2,4,6-(CF,)C,H,],Sn crystallizes in two forms.One form from cold hexane gives monomers with weak intramolecular Sn.-.F interactions and the other from hexane-toluene yields weakly associated red dimers with Sn-Sn bonds of 363.9pm some 83pm longer than single. The stannylene adds MesNC to give the stannaketenimine in which the new Sn-C bond is longer than the aryl-Sn bonds supporting coordination into the p-orbital of Sn.' l7 Reacting catechol with Cp:Si gives the aryloxysilane through OH insertion.This adduct decomposes in toluene to give the novel ionic species (12) the structure of which is supported by the Si-H stretching frequency and large Si-H coupling constant (Equation 4). l1 cp;si 1- aoH-Cp;Si /H a Ho catecho1-[CsSiH]+ ~o /~ (4) ~ OH ' 0 ,o "'H (12) Three coordinate tin cations R,Sn+ have been prepared from the hydride with Ph,C+ or (C,F,)3B or from R,SnCI and AgCIO, and '19Sn chemical shifts support its presence.' l9 + The reaction of M (M = Fe Co Ni) with 1,3,5-trisilacyclohexanein the gas phase results in the loss of one or two moles of H,. With Cp,M +,however three moles of H are lost particularly for M = Ni to give CpMC,Si,H; as the 1,3,5-trisilabenzene derivative.' 2o Hexasilylbenzene (H,Si),C results from 4-MeOC6H,SiH and is an air-stable crystalline solid m.p.165 "C,with D,,symmetry. Like (PhSiH,),C, it has a planar c ring unlike (Me,Si),C and 1 ,3,5-(Me3Si),C,H,.'" Silylating Br,C,Mn(CO) with HMe,SiCI gives the pentakis(dimethylsi1yl)cymantrene.It has a paddle-wheel struc- 112 A.G. Brook A. Baumegger and A. J. Lough Organometallics 1992 11 3088. 113 C. Couret J. Escudie G. Delpon-Lacaze and J. Satge Organomerullics 1992 11. 3176; M. Lazraq. J. Escudie C. Couret J. Satge and M. Soufiaoui ibid 1992 II 555. I I4 G. Anselme H. Ranaivonjatovo. J. Escudie C. Couret and J. Satge. Organometallics 1992 11. 2748. 115 M.G. Davidson. D. Stalke and D.S. Wright Angew. Chem. Int. Ed. Engl.. 1992 31.1226. 116 N. Kuhn G. Henkel and S. Stubenrauch. J. Chem. Soc. Chem. Commun.. 1992 760; idem.. Angew. Chem. Int. Ed. Engl.. 1992 31 778. 117 U. Lay H. Pritzkow and H. Grutzrnacher J. Chem.Soc. Chem. Commun.. 1992.260; H.Grutzmacher. S. Freitag R. Herbst-Irmer and G. M. Sheldrick Angew. Chem. Int. Ed. Engl. 1992. 31 437. I18 P. Jutzi and E.-A. Bunte Angew. Chem.. Inr. Ed. Engl.. 1992. 31 1605. 119 J. B. Lambert and B. Kuhlmann. J. Chem. Soc. Chem. Commun.. 1992 931. 120 A. Bjarnason and I. Arnason Angew. Chem.. Int. Ed. Engl.. 1992 31 1633. 121 C. Rudinger H. Beruda and H. Schmidbaur. Chem. Ber. 1992. 125. 1401 C. Rudinger. P. Bissinger H. Beruda and H. Schmidbaur. Orgunometallics 1992 11 2867. C Si Ge Sn and Pb 45 ture but in solution rapid free rotation occurs about the Si-C bond indicating less steric crowding than for (HMe2Si),C,Cr(CO),.'22 The base-free cyclopentadienylide [(p-q5:qS-C,H4(SiMe,)Li),] has a chain like polymeric sandwich structure.' 23 Cleaving Ph,PbPbPh with Bu"Li in the presence of PMDETA gives the monomeric Ph,Pb-Li(pmdeta) in which the structure shows a covalent Pb-Li bond of 285.2pm while the small CPbC angles of 94.3" suggest s-orbital character of the Pb-Li bond.'24 n-Bonding between nitrogen and silicon has long been thought to provide the explanation of the planarity and lack of basicity of (H,Si),N.(PhSiH,),N is similarly planar at nitrogen with overall C symmetry.'25 The EPR spectra of a range of silylamines also support such n-bonding but while silicon d-orbitals appear to provide the most likely acceptor orbital on silicon a*-Si-C orbitals cannot be ruled out.'" The structure of (CsHNSiMe,), a caesium-based heterocubane has Cs N and Si on the three-fold axis and Si-N bond lengths of 159 pm which indicate considerable double bond character.127 (Me,Si),NLi forms donor complexes with esters; (Me,Si),NNa 1 :2 forms com- plexes with dioxan in which Na is trigonal bipyramidal five-coordinate with dioxan bridging pairs of sodium ions in a polymer array.The rubidium and caesium derivatives are amide bridged dimers with three dioxan molecules coordinating to each metal.' 28 The unsolvated alkaline earth metal derivatives are similarly bridged dimers.' 29 The primary germylamine Mes,GeNH is only slowly cleaved by small protic reagents while Bu'COC1 gives the arnide and no Ge-N cleavage occurs.Hindrance at Ge allows acylation at nitrogen using Bu'COCl.'30 A range of aminostannanes and cyclodistannazanes have been prepared and relating structure to the 2J(119Sn' "Sn) coupling constants shows the nitrogen lone-pair to be p-type with 2,6-Pr;C,H,N(SnMe,) being planar at nitrogen. The compound MeN(SnMe,Cl) is dimeric the unexpected structure containing a diazadistannetidine unit coordinated to two Me,SnCl groups with cis orientation and involving weak Sn -. . C1 interac- tions.I3' The phosphide [(Me,Si),PLi] has a hexameric step-like structure (1 3) involving four- and five-coordinate phosphorus atoms and two- and three-coordinate lithium and Si-P bond distances of 220.7-222.1 pm.' 32 A hexamer (Et,PSiMe,OLi), also results from the reaction of Et,PLi with polysiloxane and involves a Li,O distorted hexagonal prism network (14).' 33 Coupling o-C,H,[P(SiMe,)Li(TMEDA)] with Bu'SiCl gives the novel Si-P cluster (19.' 34 122 K.Sunkel and J. Hofmann Organometal!ics. 1992 11. 3923. lZ3 W. J. Evans T. J. Boyle and J. W. Ziller Organornetallics. 1992. 11 3903. lZ4 D. R. Armstrong M.G. Davidson D. hloncrieff. D. Stalke and D. S. Wright. J. Chem. Soc.. Chem. Commun.. 1992 1413. N. Mitzel A. Schier and H. Schmidbaur Chem. Ber. 1992. 125. 271 I. IZ6 C.J. Rhodes J. Chem. Soc. Perkin Trans. 2 1992 235. K. F. Tesh B. D. Jones T. P. Hanusa and J.C. Huffman J. Am. Chem. Soc. 1992 114 6590. 12* P.G. Williard Q.-Y. Li and L. Lochmann J. Am. Chem. Soc. 1992,114,348;F.T. Edelmann F. Pauer M. Wedler. and D. Stalke Inorg. Chem.. 1992 31 4143. 129 M. Westerhausen and W. Schwarz 2. Anory. Ally. Chem. 1992 609 39. M. Riviere-Baudet. A. Morere. J. F. Britten and M. Onyszchuk J. Organornet. Chem. 1992 423 C5. 13' S. Diemer H. Noth K. Polborn and W Storch Chem. Ber.. 1992 125 389. 132 E. Hey-Hawkins and E. Sattler J. Chem. Soc.. Chem. Commun. 1992 775. '33 R. A. Jones. S.U. Koschmieder. J. L. Atwood and S.G. Bott. J. Chem. Soc. Chem. Commun.. 1992,726. D. A. Armitage (13) Me3Si substituents omitted (14) SiMe2PEt2 substituents omitted (15) Oxidizing the phosphide complex (Me,Si),PCr(CO); with BrCH,CH,Br gave the tetraphosphabutene complex [(DME),Li+],[Me,Si(Cr(CO),),P-P=P-P(Cr(CO),),SiMe3l2- as the trans product with P-P single and double bonds.'35 The phosphasilene Is,Si=PSiPr\ reacts with Ph,CN to give a range of products.At 0 "C [2 + l]cycloaddition occurs to give the azaphosphasiliridene (16) which thermolyses to give the phosphasiliridene (17) the diazaphosphacyclopentene as the [2 + 31 cycloadduct and the benzocyclopentene (18) the only product formed if the reaction is conducted at 110 "C (Scheme 3). The analogous arsasilene adds Ph,CO and Te.'36 Is2Si =PSiPr; PhZCN2 + I N I1 CPh2 Jheat SiPri 1s2si-p~ x Ph Ph Scheme 3 Coupling Cp*SiC13 with LiAI(PH,) gives Cp*Si(PH2) which at room temperature condenses to the diphosphadisilacyclobutane. 37 The hindered [Mes(Bu')SiPH] can be readily substituted at phosphorus by Bu'Hg groups the product photolysing to the bicycloCl.1 .O]butane (Equation 5).The arsenic analogues result similarly using [Mes(Bu')SiAsH] as starting material.' 38 134 P. B. Hitchcock M. F. Lappert and P. Yin J. Chem. Soc.. Chem. Commun. 1992 1598. 135 G. Fritz E. Layher H. Krautscheid B. Mayer E. Matern W. Honle and H. G.von Schnering Z. Anorg. Allg. Chem. 1992 611 56. M. Driess and H. Pritzkow Angew. Ckem. Int. Ed. Engl. 1992 31 751 and 316. 13' M. Baudler W. Oehlert and B. Tillrnanns Z. Naturforsch.. Teil B. 1992 47 379. 13' M. Driess Phosphorus Sulpur Silicon Relat. Elem.. 1992,64,39; M. Dreiss R. Janoschek and H. Pritzkow C Si Ge Sn and Ph 47 P-P Bu'Li [Mes(But)SiPHl2 -[Mes(Bu')SiPHgBu'J2 aBU~.siy\ii BU' (5 Bu'HgC1 II Mes Mes A disphosphabicyclo[ 1.1 .O]butane compound can also be made directly by heating Mes(Bu')Si=Si(Bu')Mes with white phosphorus. The initial product is an Si,P adduct which on heating give the exo-em-disiladiphosphabicyclo[1.1.O]butane as the dominant isomer. With Mes,Si=SiMes and As, the intermediate Si,As adduct can be isolated as a tricyclic Si-As ring system (19) that gives the bicycle[ 1.1 .O]butane at 95 "C (Equation 6).'39 AS-AS MqSi As-SiMq MqSi =SiMes -I.,'As-As' I I MesS!i'\h4es I (6) I + Mes,S1 (19) 'As -SiMes Mes Ma As4 Coupling Mes(Bu')GeF with LiPH,.DME gives the 1,3,2,4-diphosphadigermetane as the trans-isomer with regard to Ge substituents but a 1 :1 mixture with regard to phosphorus.Lithiation followed by reaction with Bu'HgC1 gives the 1,3-dimercury derivative which on photolysis gives the diphosphadigermabicyclo[ 1.1 .O]butane. 140 Reacting (Na/K)HP with R,SnCI gives the tetraphosphabicyclo[ 1.1 .O] butanes (20) which are only stable in solution (Equation 7).141 The diphosphadistannetanes (BubSnPR') (R' = H,Me) react with Bu\SnCl to give the distannylphosphine which can be aminated with LiNHBu' condensation with Me2SiCI2 giving the mixed heterocycle (21) (Scheme 4). 142 The stannaphosphene Is,Sn=PMes* readily adds water and methanol (Mes* = 2,4,6-B~',c,H,).'~~ (Na/K)HP4 + R3SnCl -R3Sn-P0f)\PH (7) 'P' (20) The reduction of ketones by silanes R,SiH catalysed by Ph,C+B[3,5-(F3C)2C6H3]i gives the siloxycarbenium ions such as [Ph,C=OSiMe,] as + intermediates that can be alternately considered as silyl substituted oxonium salts.44 Hydrogen bonding to aryl groups is observed in TsiSiPh(X)OH and to the ester group Angew. Chem. Int. Ed. Engl. 1992 31 460. '39 A. D. Fanta. R. P. Tan N. M. Comerlato M. Driess D. R. Powell and R. West. Inorg. Chim. Actu. 1992. 19%200,733;R. P. Tan N. M. Cornerlato D. R. Powell and R. West Angew. Chem.. Inr. Ed. Engl. 1992 31 1217. 140 M. Driess H. Pritzkow and U. Winkler Chem. Ber. 1992 125. 1541. 141 M. Baudler and B. Wingert Z. Anorg. Allg. Chem. 1992 611. 50. 142 a. Hanssgen E. Stahlhut. H. Aldenhoven and A. Dorr. J. Organomet. Chern. 1992 425 19. H. Ranaivonjatovo. J. Escudie C. Couret and J. Satge J. Chem. Soc.Chem. Commun. 1992. 1047. M. Kim T. Hino and H. Sakurai. J. Am. Chem. Soc. 1992 114. 6697. 143 144 D.A. Armitage L~NHBU' R' Scheme 4 of TS~S~(OH),(OCOCF,).'~~ A wide range of siloxides results from silanols e.g. BuiSiOH and Ba granules giving the siloxide bridged dimer Ba,(OSiBu\);THF and Me,Al and Ph,SiOH the monomeric (Ph,SiO),AI-THF which solvates water without hydroly~is;'~~ titanium substituted siloxanes result from Cp*TiC13 (Cp* = Me,C,) and CpTSi(OH) or Ph2Si(OH)2,'47 while the triol Bu'Si(OH) and Re207 give the cyclotetrasiloxane [O,R~OS~(BU')O],;'~~ the triol [(c-C,H )7Si709(OH)3] gives a range of silasesquioxanes BI and OV(OPr") giving a dimeric products and SbMe a series of monomers. '49 The silyl peroxide Me,SiOOSiMe can be conveniently prepared from the hexamethylenetetramine:H,O complex with Me,SiCl.' 50 Oxidizing the stannylene [(Me,Si),N],Sn with 0 gives the remarkable p-peroxy derivative [Sn(N(SiMe,)2}2(p-0,)] in which the ring has an almost perfect twist-boat structure with an 0-0 bond length of 150.1pm.lS1 Condensing (Bu",nO) and Re207 forms the terminally metallated distannoxane and Me,SiOReO with (Me,Sn),N the monomeric amide (Me,Sn),NReO,.' s2 While condensing RSiCl (R = Me Et) with Na2X (X = S Se) gives (RSi),X with the expected adamantane-like structure,' 53 Bu'GeC1 with H2S and pyridine gave the bisgermanethiol isomers (22) which slowly thermolyse to the adamantane-like cage (23) (Equation 8).However the reaction of Bu'GeC1 with (NH,)2S gave the 'double-decker' isomer (24) which has eight- and four-membered rings (Equation 9).The Ge-S bonds of the four-membered rings (224.3 pm) are distinctly longer than the rest (221.6pm). Heating converts (24) to (23).' 54 14s S.S.Al-Juaid A. K. A. Al-Nasr C. Eaborn and P. B. Hitchcock J. Orgunornet. Chrm. 1992,429 C9; S.S. Al-Juaid C. Eaborn and P. B. Hitchcock ihid. 1992. 423. 5. '46 S.R. Drake W. E. Streib K. Folting M. H. Chisholm and K.G. Caulton fnorg. Chem. 1992,31 3205; A. W. Apblett A.C. Warren and A. R. Barron. Can. J. Chem. 1992 70. 771. 14' K. J. Covert P.T. Wolczanski S.A. Hill and P.J. Krusic. Inorg. Chrm. 1992 31; 66; F.-q. Liu H.-G. Schmidt M. Noltemeyer C. Freire-Erdbrugger G. M. Sheldrick and H. W. Roesky 2.Naturforsch.Teil B 1992 47 1085. 148 N. Winkhofer H. W. Roesky M. Noltemeyer and W.T. Robinson Angrw. Chem. Int. Ed. Engl. 1992 31 599. F. J. Fehr T. A. Budzichowski and J. W. Ziller. Inorg. Chem.. 1992,31,5100:F.J. Feher and R. L. Blanski J. Am. Chem. Soc. 1992 114 5886; F J. Feher T.A. Budzichowski. K. Rahimian. and J. W. Ziller ihid.. 1992 114 3859. I so P. Babin B. Bennetau. and J. Dunogues Synth. Commun.. 1992 22 2849. IS1 R. W. Chorley P. B. Hitchcock and M. F. Lappert. J Chem. Soc. Chem. Commun.. 1992. 525. Is2 U. Wirringa H. W. Roesky H.-G. Schmidt and M. Noltemeyer Chrm. Ber.. 1992 125 2359. 153 S.R. Bahr and P. Boudjouk Inorg. Chrm. 1992 31 717. IS4 W. Ando T. Kadowaki. Y. Kabe. and M. Ishii. Angew. Chrm. lnt. Ed. Engl.. 1992. 31. 59. C Si Ge Sn and Pb But But ,Ge.S-Ge-S I ButGeC1 ~~./pyridine But 1 ISI -Bu'Ge. 1 -s,GeBu' (8) * HS($ S/'Ge-' 'Ge" But But (23) (22) ButGeZs )GeBu' s\ Bu'GeC13 + (NH4),S5 -< S But\Ge1;;deBut (24) Heating the silane TsiSiH with the elements sulfur or selenium gave the tetrathia or tetraselena-l,4-disilabicyclo[2.1. llhexane. The tetraselena derivative gives the triselenac 1.1.llpropellane on photolysis the structure indicating an Si . . .Si distance of 25 1.5 pm and Si-Se bonds of 23 1.6-232.7 pm. ' Condensing Cp,TiC1 with 2Li,S and Ph,MCl (M = Si Ge) and (MeC,H,),TiCl with Li,S/Ph,SnCl, gave the four-membered titanocycles. The silicon derivative with S,Cl gave Cp,TiCl and the sulfur-rich heterocycle (25) as a colourless wax which decomposes above -20 "C(Equation lo).' 56 The more hindered tetraselenagermolane (26) which results from the hydride with Bu'Li then selenium occurs as orange crystals mp 209"C and in the presence of 2,3-dimethyl-buta- 1,3-diene gave the cis-substituted ],3,2,4-diselenadigermetane (27) (Equation 11 ).' 57 (26? Tb = 2,4,6-[(Me3Si)&H]3C6H2 H.Yoshida and W. Ando Phosphorus Siilfur Silicon Relut. Elem.. 1992.47.45;H. Yoshida Y. Takahara. T. Erata and W. Ando J. Am. Chem. Soc. 1992 114 1098. 15' J. Albertsen and R. Steudel J. Orqanomet. Chem. 1992 424 153. Is' N. Tokitoh. T. Matsurnoto and R. Okataki. Tetruhedron Let[. 1992 33. 2531. 50 D. A. Armitage The tin-sulfur and selenium analogues of (26) react with Ph,P to give the dichalcogenadistannetaneas the cis-isomer probably through the intermediacy of the monomeric stannanethione or ~elone.'~' The hindered tin heterocycle (28) (X = S) reacted with Ph,CN on heating to give three carbene insertion products (29) (30),and (31) (Equation 12).Compound (28) (X = Se) gives no selenium analogue of (31).'59 With (Me,N),P (31) (X = S) can be converted to (30) (X = S) and the 1-stanna-2,4-dithiacyclobutane, while the selenium analogue of (29) gives that of (30) under similar conditions. The hindered silyl chlorides (Mes*X),SiCI (X = S Se) react with AgClO to give a range of sulfides and selenides which are thought to result through the intermediacy of the silicenium ion which decomposes to Mes*X+ and (Mes*X),Si (X = S) or the radical Mes*X.(X = Se).16' (Me,Si),SiLi(thf) reacts with Te to give the tellurate derivative as a covalent dimer with Li-Te bridges. With 12-crown-4 or Et,NCI ion separation results.I6' The tellurol which results from the lithium derivative and triflic acid can be used to make an extensive series of covalent metal derivatives for example with alkaline earth metals'62 and for groups 4 12 and 13. Oxidation of group 4derivatives gives the dark green ditelluride (Me,Si),SiTeTeSi(SiMe,) (Scheme 5).16 ((Me3SW12M (Me3Si)3SiTeLi(THF)3 CF3S03H -(Me3S03SiTeH = Ca Sf Ba zn Cd Hg* [(Me3SihSiTehM [(Me3Si)zCHIZGaBr %M' M' = Zr Hf I I [(Me3Si)2CH]2GaTeSi(SiMe3)3[(Me3Si)3SiTeI4M' [(Me3Si)3SiTe]2 Scheme 5 Halogen bridging features extensively in tin chemistry but not in that of silicon.Consequently the reaction of fluoride with o-bis(fluorosily1)benzene is of particular interest in giving the adduct with fluorine bridging the two silicon sites. The three I58 N. Tokitoh Y. Matsuhashi M. Goto and R. Okazaki Chem. Lett. 1992 1595. I59 N. Tokitoh Y. Matsuhashi and R. OKazaki Tetrahedron Lett. 1992 33. 5551. 160 N. Tokitoh T. Imakubo. and R. Okazaki. Tetruhedron Lett.. 1992 33 5819. I61 G. Becker K. W. Klinkhammer. S. Lartiges. P. Bottcher,and W. Pol1.Z. Anorg. AIlq. Chrm.. 1992,613.7; P.J. Bonasia D. E. Gindelberger B.O. Dabbousi and J. Arnold J. Am. Chem. Soc. 1992 114 5209. 162 D. E. Gindelberger and J. Arnold J. Am. Chem. So(,.,1992,114,6242;G. Becker K. W. Klinkhammer W. Schwarz M. Westerhausen and T.Hildenbrand Z. Nuturfimch.. Teil E 1992 47 1225. 163 V. Christou and J. Arnold J. Am. Chem. Soc. 1992. 114.6240; P. J. Bonasia and J. Arnold. Inorg. Chern.. 1992,31,2508;W. Uhl M. Layh. G. Becker. K. W. Klinkhammer. and T. Hildenbrand Chem. Ber. 1992 125 1547. C Si Ge Sn and Pb fluorosiliconates (32) (33) and (34)all have bent fluorine bridges (1 18.6"to l26.lL) but even with similar substituents on each silicon the two bridge bonds differ in length by some 17 pm.16 A wide range of diorganosiliconates RR'SiF; shows inequivalent apical-fluorines due to the proximity of the counter-cation but both are longer than the equatorial Si-F bonds.'65 8-Dimethylaminonaphthyltetrafluorosiliconateinvolves six-coordination in which the Si-F bond trans to the coordinating amino group is shorter than the other three Si-F bonds.'66 1-1-1- I I Triphenyltin fluoride has a bridged polymeric one-dimensional structure with Sn five-coordinate and both Sn-F bonds of equal length.16' Adding Et,NF to Me,SnF gives the organofluorostannate salt Et,N + Me,Sn,F containing a linear fluorine bridge.The anion includes cyclic Sn,F units interconnected at two tin atoms. All tin atoms are six-coordinate. 168 Schifl bases stabilize the Me,Sn,Cl;- ion which has chloride bridges and the four methyl substituents two above and two below the Sn,C16 plane. '69 I64 K. Tarnao. T. Hayashi Y. Ito. and M. Shiro Orqunornerullics. 1992. 11 2099. I h5 K.Tarnao. T. Hayashi Y. Ito and M. Shiro Orqanomeiallics.1992. 11. 182. 166 C. Breliere. F. Carre R.J. P. Corriu. W. E. Douglas. M. Poirier. G. Royo. and M. Won& Chi Man Orqonomrtallic.s 1992. 1I 1586. 167 D.Tudela E. Gutierrez-Puebla. and A. Monge. J. Chrm. Soc.. Dalron Truns.. 1992. 1069. IhX T. H. Larnbertsen. P. G. Jones. and R. Schrnutzler Polyhedron. 1992 11. 331. 169 S.-G. Teoh. S.-B.Teo. G.-Y. Yeap and H.-K. Fun. J. Orqunomri. Chem.. 1992 439. 139.

ISSN:0260-1818    

DOI:10.1039/IC9928900033

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

5 N P As Sb and Bi By D. A. ARMITAGE Department of Chemistry King's College London Strand London WC2R 2LS UK 1 Halogen Derivatives Calculations regarding the vibrational stability of covalent NF and NF have been re-evaluated. They support NF adopting D, symmetry but severe ligand crowding would suggest the more stable ionic structure NF;F-. though this would be unstable relative to NF and F, even at -142°C.' An extensive range of halophosphonium salts has been made and their vibrational spectra compared. They include PX4-,F,+ (X = H D; n = 04) Cl,-,Br,PSBr+-AsF (n = 0-3) X,FPSMe'MF (X = Br CI) XF,PSMe+SbF (X = Br C1 F) and Me,PCl(SMe);-,Cl-. Structures have been determined for Me,PSMe+T and MeP(SMe)Cll SbC1 .3 Magic-angle spinning 31 P NMR spectroscopy of Me,PXl- (X = C1 Br) provided support4 for the presence of isomers of both MePCllC1- and Me,PCl;Cl-.The mixed cations MePCl,Br+ MePClBr,' ,and Me,PCl; have also been observed. The Br adduct of Ph,P has been shown to have a covalent four-coordinate structure Ph,P-Br-Br analogous to the iodine adducts Ph,M-1-1 (M = P AS).^ Reaction of cobalt powder with Me,PI gives the five-coordinate CO(III) complex (Me,P),CoI,; Bu;PI yields the 'frozen transition state' complex [(Bu;PI)~(,LI- I)][ (Bu~PPI)(p-I)Co13] .6 AsF forms a range of nitrile adducts and complexes with 1,3,5-triazine to give 1 1 2 1 and 3 1 adducts.' Oxidative fluorination of AsCI with XeF'AsF; gives the arsonium salt FAsCli AsF .8 Reacting the anions As,Cli- and AsSBr, as their Ph4P+ salts with M(CO) (M = Cr W) in thfgives Ph,P+AsX,(thf); (X = C1 Br) as major products.The D4,-like structures show no lone-pair stereochemical activity but K. 0.Christe and W. W. Wilson J. Am. Chem. So(,. 1992. 114. 9934. R. Minkwitz D. Lennhoff W. Sawodny. and H. Hartner Z. Narurforsch. Ted B. 1992. 47 1661; R. Minkwitz T. Hertel and G.Medger Z. .4norg. Ally. Chem.. 1992,615,114; R. Minkwitz P. Garzarek and G. Medger ibid 1992 612 40. R. Minkwitz G. Medger. R. Greth. and H. Preut Z. Narurjorsch. Teil B 1992 47 1653. R. K. Harris A. Root P.N. Gates and A. S. Muir Spectrochim. Acta A 1992 48 1371. N. Rricklenank S. M. Godfrey. A. G. Mxkie. C. A. McAuliffe and R. G. Pritchard J. Chem. Soc. Chem. Commun.. 1992 355. C.A. McAuliffe. S. M. Godfrey A.G. Mxkie and R.G.Pritchard Anyrw. Chrm.,Int. Ed. Enyl.. 1992.31 919. I. C. Tornieporth-Oetting and T. M. Klapotke Chem. Ber. 1992. 125. 407; I.C. Tornieporth-Oetting. T. M. Klapotke. U. Behrens and P. S. White. J. Chem. Soc. Dalton Trans. 1992. 2055. R. Minkwitz and W. Molsbeck Z. Anory. Ally. Chem. 1992 607 175. 53 D. A. Armitage the As-X bonds are longer than single.' Oxidation of (Ph,P),AS,Cl with ozone gives Ph,P+AsCl and Ph,PCI.H,AsO, while (Ph,P),Sb,Cl gives Ph,P+SbCl; and (Ph,P),(SbOC1,)2~2CH2C12.'o The haloarsenates As,X (X = Br I) have novel structures in which a central AsX octahedron shares two faces of common vertex with two face-bridged terminal octahedra in which the bridge bonds are longer than the terminal ones. * ' Hydrogen fluoride reacts with R,N+SbCI; to give a range of mixed anions containing two to six fluorine atoms as established by 12'Sb and 19F NMR spectroscopy.'2 While Ph,SbF gives only Ph,SbCl upon reaction with chlorine the bromine reaction gives a range of mixed products including Ph,SbBr,F-SbPh,Br, which possesses a fluorine bridge.Hydrolysis of this gives (Ph,SbBrF),O which itself contains a strong intramolecular fluorine bridge and has antimony in both five and six-coordination states as does the original bromination product.' The anions Ph,SbX (X = CI Br) show V-trigonal bipyramidal structures with axial halogens. With Ph,Sb,X;-(X = C1 Br) however coordination is square pyramidal resulting in a wide-angled Sb-X-Sb bridge. l4 CH,(SbCl,) adds bromide to give [(BrC1,Sb),CH,l2 -,which itself adds Br to each Sb site at -78 "C.' 15-crown-5 complexes with SbBr, MeSbX (X = CI Br) and PhSbBr,.The structures of the bro- mides show all five oxygen atoms to be bonding thus making Sb eight-coordinate.16 MeSbI adopts a structure with association through iodine bridges thus forming a chair-like structure. It reacts with Me,Sb+I- to form the adducts (Me,Sb+),- MeSbIi- which comprise tetrahedral cations and square pyramidal anions.' The stibines (Me,XCH,),Sb (X = C Si) add iodine and the resultant adducts decompose at 170°C to R,SbI. Further addition of iodine gives R,SbI, which decomposes at room temperature to RSbI,. The halides Me,CCH,SbBr and (Me,CCH,),SbI can be readily reduced and provide intermediates for the vapour phase deposition of antimony.' [18]AneS forms a 1 1 complex with BiCl that has all six sulfur atoms coordinating in an unusual S-shaped conformation and possessing three-fold symmetry.' 'BiBr forms a 2 1 charge transfer complex with [2.2]paracyclophane in which the aryl rings n-bond to BiBr which has a halogen-bridged chain structure.20 Condensing Me,P into solid BiBr gives Bi,Br,(PMe,) in low yield as a centro- symmetric edge-shared bi-octahedral bromide-bridged dimer with cis phosphine ligands one of which is trans to a bridging bromine.Bi,Br,(PMe,Ph),(OPMe,Ph) results with PhMe,P (and adventitious oxygen).,' BiCl complexes with 15-crown-5 B. Siewert and U. Muller Z. Naturforsch. Teil B 1992 47 680. lo K. Ruhlandt-Senge A.-D. Bacher and U.Muller Z. Naturfimch. Ted B 1992 47 1677 I' W.S. Sheldrick and J. Kiefer Z. Naturforsch. Teil B 1992 47 1079. M. F. A. Dove and J.C. P. Sanders J. Chem. SOC. Dalton Trans. 1992 331 1. I3 S. P. Bone M. J. Begley and D. B. Sowerby J. Chem. SOC. Dalton Trans. 1992 2085. l4 W. S. Sheldrick and C. Martin Z. Naturforsch. Teil B 1992 47 919. Is S. Kraft and M. Wieber Z. Anory. Ally. Chem. 1992 607,157. l6 M. Schafer J. Pebler and K. Dehnicke Z. Anorg. Ally. Chem. 1992 611 149. " H. J. Breunig K. H. Ebert S. Guelec M. Drager D. B. Sowerby M. J. Begley and U. Behrens J. Organornet. Chem. 1992 427 39. D.G. Hendershot J.C. Pazik C. George and A.D. Berry Organometallics. 1992 11 2163; D.G. Hendershot J. C. Pazik and A. D. Berry Chem. Muter. 1992 4 833 (Chem. Ah. 1992 117 131 282).l9 G. R. Willey M.T. Lakin and N. W. Alcock J. Chem. Soc. Dalton Trans. 1992 1339. 1. M. Vezzosi L. P. Battaglia and A. B. Corradi J. Chem. Soc. Dalton Trans. 1992 375. W. Clegg R. J. Errington R. J. Flynn M. E. Green,D. C. R. Hockless N.C. Norman,V. C.Gibson,and K. Tavakkoli. J. Chem. Soc. Dalton Trans. 1992. 1753. N P As Sb and Bi 55 and 18-crown-6 while BiBr with the latter gives the ionic product (18-crown- 6)BiBrlBiBri. The anion is polymeric as is that in (pentaethylene glycol)BiI~Bi,I; .22 The thf complex PhBiX,(thf) (X = Br I) crystallizes as a halogen bridged one-dimensional polymer with square pyramidal coordination and apical phenyl groups; reaction of the iodide with Et,NT gives the anion Ph,Bi,Ii- as a centrosymmetric edge-shared square pyramid.Ph,BiBr(thf) and Ph,BiBr; show V/-trigonal bipyramidal structures with both phenyl groups and lone pairs being eq~atorial.'~ The condensed phase Bi 1414 comprises a one-dimensional ribbon of chair Bi interconnected rings that is six rings wide with alternate bismuth atoms on the edge of the ribbon bonding to two iodine atoms.24 2 Transition Metal Clusters The dinitrogen complex [(Cp:ZrN,),p-N,] reacts with phosphine to give the dimeric phosphide bridged derivative [CpzZr(H)PH,],. This reacts with alkenes and PH to generate primary alkyl phosphines under the mildest conditions reported to date.25 The bisphosphido complex (CpTZrPHMes) loses MesPH to give the first early transition metal phosphinidene complex CpTZr=PMes which decomposes to the isomeric phosphametallocycle through C-H addition across the Zr=P bond.It also adds MesPH with H elimination to give the diphosphametallocycle. All three compounds add MeCN to give P and N substituted metallocycles.26 Cp,Zr generated from Cp,ZrCl and Bu"Li in situ oxidatively adds PhPH to give an intermediate complex which itself decomposes through C-H activation to give the Zr(m) diphosphide and fulvalenide bridged complex. Ar*PH (Ar* = 2,4,6-tri-t-butyl-phenyl) gives a trimeric phosphide-capped Zr(1v) species thus providing a rare example of a tricapping phosphorus atom formed via Ar*-P cleavage.27 Bu',P, on heating with either Fe(CO) or Fe,(CO), gives BU\P,Fe,(cO) with a P chain end-bonding to the Fe,(CO) residue; the use of Fe,(CO) at room temperature also yields Bu',P,Fe(CO),Fe,(CO), in which the central P atom bonds to the Fe(CO) residue.28 The reaction between NiCI and Bu\P in the presence of (Me,Si),P leads to [Ni(PBu'),] in which Ni is surrounded by a hexagonal plane of six P atoms., White phosphorus reacts with Fe,(CO) in benzene under reflux to give the complex (Fe(CO),(pP,)},(p-Fe,(CO)6}2in which almost square P units (P-P bonds 21 3.0 and 21 2.4 pm j chelate to Fe(CO) in the same plane.This is orthogonal to that of the two Fe,(CO) units.30 When white phosphorus reacts with Bu'C5H,Rh(CO), one P-P bond of P is cleaved and in the presence of (thf)Cr(CO), Bu'C,H,R~(CO)P,[C~(CO)~],,in which the P ligand has a butterfly-like bicyclo[ 1.1.O]butane structure is obtained.22 R. D. Rogers A. H. Bond S. Aguinaga. and A. Reyes J.Am. Chem. Soc. 1992 114 2967. 23 W. Clegg R. J. Errington G. A. Fisher L). C. R. Hockless. N. C. Norman A. G. Orpen and S. E. Stratford J.Chem. SOC. Dalton Trans. 1992 1967. 24 E. V. Dikarev B.A. Popovkin and A. V. Shevelkov. Z. Anorg. Allg. Chrm. 1992 612 118. 25 S. Nielsen-Marsh R. J. Crowte and P.G. Edwards J.Chem. Soc.. Chem. Commun.. 1992 699. 26 Z. Hou and D. W. Stephan J. Am. Ch(1m. Soc. 1992 114 10088. 21 J. Ho and D. W. Stephan Oryanometallics 1992 11. 1014. 28 Y. W. Li M.G. Newton N. K. Bhattacharyya. and R. B. King Inory. Chem. 1992 31 2069. 29 R. Ahlrichs D. Fenske H. Oesen and U. Schneider Anyew. Chem. Int. Ed. Engl. 1992 31 323. 30 M. Scheer M. Dargatz K. Schenzel and P.G. Jones J.Organomet. Chem. 1992 435 123. 31 M. Scheer C. Troitzsch and P. G. Jones. Angew. Chem. Int. Ed. Engl. 1992 31 1377. 56 D.A. Armitage In decalin at 170”C Cp“Rh(CO),[Cp” = 1,3-Bu:C,H3] and E (E = P As) give (Cp”Rh),E,-E,(RhCp”) and [(Cp”Rh)(p,q2 :q2-E2)], the former involving the P, ligand acting as both a o and n donor ligand to Rh., By way of contrast heating Cp”Nb(CO) with P gives the triple decker sandwich Cp”Nb(p-q6 :q6-P,)NbCp” in which the P ligand behaves as a double n-ally1 donor with four short and two long P-P bonds. The ability of P and As to undergo far greater out-of-plane distortions than benzene provides for a greater variety of structures in these triple decker sandwich compounds.33 Photolysing [Cp4Ni(p-C0)] (Cp4 = PrbC,H) with P or heating with As gives CpiNi,E and Cp4Ni(q3-E,) (E = P As).The structure of the first of these involves a Ni,As trigonal prism with the Ni atoms at opposite corners of one rectangle., Cp*M(q’-E,) (E = P As; M = Fe Ru) n-complexes with M’(CO) residues (M’ = Cr Mo) through the E ring. Three of the Fe derivatives of both P and As rings show equal bond lengths within the E rings that are shorter than usual single bond lengths while for the two derivatives Cp*Fe(p-q5 ,As,)M‘(CO)~ the As-As bonds appear slightly longer in the Mo than Cr derivatives.,’ Phosphenium and arsenium complexes CpW(CO),=ER and the methylphos- phinidene unit from (MeP) react to give a metallo substituted heter~cycle.,~ The phosphine and arsine complexes (CO),CrEPh,H -,(m = 1,2) react with alkynes uia insertion into the E-H bond to give vinyl c~mplexes.~’ (p3-As)(RC,H,),Mo,(CO) (R = H Me) and Cp,Mo,(CO),As coordinate to iron carbonyl residues to give p4-As derivatives; mixed p-As clusters result from p3-AsCp,Mo,(CO) and Cp,Ni,(CO) or (Ph,P),PtC2H,.38 The As tetrahedron can be progressively opened by Cp*Co(CO) residues to give Cp*Co(CO)(q” ’-As,) [Cp*Co(CO)],(p-q’ ’-AS,) and Cp*Co(p-q4 ’:‘-As,)Co(CO)Cp* the last of which involves a cis-As chain acting both as a n-type ligand to Cp*Co and as a terminal o-bonded ligand to Cp*Co(CO) residues.39 CptSm dealkylates Bu”,b in thf to give the complex (CptSm),(p-q2 :q2:q’-Sb,).thf which contains the bent Sb;- anion and also has 1,2 and 1,3 chelation to two Sm entities and coordinates to the third; the Sb-Sb bond lengths of 268.8 pm are shorter than usual single bond lengths.,’ CpMo(C0); and SbCl react to give the Mo-Sb cluster (p4-Sb)2Cp,Mo,(CO), in which each Sb atom is o-bonded to CpMo(CO) and [CpMo(CO),] residues and coordinated to CpMo(CO) and Mo(CO) residue^.^' A range of mononuclear polydentate Sb and Bi substituted complexes of Fe Cr Mo and W has been made., 32 0.J.Scherer B. Hoebel and G. Wolrnershauser Angew. Chem. Int. Ed. Engl.. 1992 31 1027. 33 A. C. Reddy E. D. Jernmis 0.J. Scherer R. Winter G. Heckrnan and G. Wolrnershauser Organomera/-lics 1992 11 3894. 34 0.J. Scherer J. Braun P. Walther and G. Wolrnershauser Chem. Ber.. 1992..125 2661. 35 9. Rink O.J. Scherer. G. Heckman and G. Wolrnershauser. Chem. Ber..1992. 125. 1011. 36 W. Malisch K. Hindahl and R. Schernrn. Chem. Ber.. 1992 125 2027. 37 H. Lang and U. Lay J. Organomet. Chem. 1992. 441 389. 3R M. Gorzellik 9. Nuber,and M. L. Zeig1er.J. Orgunornet. Chem. 1992,436,207;M.Gorzellik 9.Nuber T. Bohm and M. L. Ziegler ihid. 1992 429 173. 39 0.J. Scherer K. Pfeiffer and G. Wolrnershauser Chem. Ber.. 1992 125 2367. 40 W. J. Evans S.L. Gonzales and J. W. Ziller. J. Chem. Soc.. Chem. Commun. 1992 1138. 41 M. Gorzellik 9. Nuber and M. L. Ziegler J. Organornet. Chem. 1992 431. 171. 42 K. Merzweiler and L. Brands. Z. Naturjorsch. Teil B 1992,47,978; F. Bringewski G. Huttner. W. Imhof and L. Zsolnai J. Organornet. Chem. 1992 439 33; W. Clegg N.A. Cornpton R. J. Errington G.A. Fisher D. C. R. Hockless N. C. Norman N.A. L. Williams S.E. Stratford. S.J. Nichols. P. S.Jarrett and A. G. Orpen J. Chem. Soc. Dalton 7ran.s. 1992 193; W. Clegg N. A. Cornpton R. J. Errington. G.A. Fisher D.C. R. Hockless N.C. Norman A.G. Orpen. and S.E. Stratford hid.. 1992 3515. N P As Sh and Bi Ni6(CO):; and BiCl react to give Ni,,Bi,(CO); (n = 2 3) which comprises a pl'-Ni unit atom contained in a Ni,,Bi ic~sahedron.~~ 3 Pnictogen Clusters Heating KP or KAs with Cs,P, and MX (M = Ga In; X = P As) to 950 K gives the alkali metal derivatives of MP3- or MAS:- respectively in which the anions are polymeric and contain four-membered rings connected in a spiro fashion as in SiS,., CUP comprises 2D anions of boat-like P rings (cf-black phosphorus with chair rings) with one P-P bond broken per Pi- unit.Cu(rkCu(~) bonding results cia P-bridging in Cu,P rings and through-space interactions of dt s and p orbitals.45 The structure of Ca,,GaAs, comprises tetrahedral GaAs units and linear As units with a hyper- valent three-centre four-electron bond and provides the first example of a discrete hypervalent Group- 15 linear anion., [Na(2,2,2-crypt)l3Sb;1 comprises the anion with idealized D symmetry similar to that found in and calculated for P:;.,' Calculations indicate that the Mulliken population of the 'A ground states of P to Bi shows little difference in s and p orbital population and only a 0.18 to 0.16 contribution for d orbitals. With Bi there is a full contribution from the 6s orbital electrons due to relativistic stabili~ation.~~ With P6 the benzvalene and prismane-like isomers are the most stable with the planar D, benzene analogue the least stable.For P, the polycyclic structure (1 ) is the most stable but this is less by 49 kcal mol- ' than two P molecules.49 Disilenes ring open P and As to give the bicyclo[ 1.1 .O]butane analogue (2) that for As being formed cia the tricyclic intermediate (3).50Ph,P,As, which contains alternating pnictogen atoms complexes with the Mo(CO) residue as a twist-boat conformation with phosphorus atoms at positions 1 and 4 in the ring showing scrambling to have preceded complex f~rmation.~ ' 4 Chalcogen Derivatives The dithionitryl salt SNS' AsF, which results from the reaction between sg S,N, and AsF in liquid SO with a trace of Br, readily adds successively to each CN group of KC(CN), the monoadduct crystallizing as polymeric sheets of the dithiadiazole 43 V.G. Albano. F. Demartin M. C. Iapalucci,G. Longoni. M. Monari.and P. Zanello. J. Chem. Soc. Dalron Trans.. 1992 497. 44 M. Somer. K. Peters and H.-G. von Schnering. Z.Anory. Ally. Chem.. 1992. 613. 19. 45 P. Alemany S. Alvarez. M.-H. Whangbo and M. Evain. Inory. Chrm.. 1992. 31. 119. 46 R. F. Gallup C. Y. Fong and S. M. Kauzlarich. Inory. Chrm.. 1992. 31. 115. 47 U. Bolle and W. Tremel. J. Chem. So(,..Chem. Commun.. 1992. 91 R. 0.Jones and G. Seifert. J. Chem. Phys. 1992 % 7564. 4R H. Zhang and K. Balasubramanian J Chem. Phy.5.. 1992. 97. 3437. 49 D. S. Warren and B. M. Gimarc. J. Am. Chem. Soc.. 1992.114.5378; R.Janoschek Chem. Ber.. 1992.125. 2687. 50 A. D. Fanta R. P. Tan. N. M. Comerlato. M. Driess. D. R. Powell. and R. West. Inory. Chim. Ac,ro. 1992. 198-200 733. 51 A. L. Rheingold and F. P. Arnold Inory. Chim. Actu 1992. 198 200. 139. D.A. Armitage unit and in the triadduct the dication adopts C, symmetry. A structure determination of the benzothiarsolium cation supports pn-bonding between arsenic and A range of cyclic thiophosphates P,S (n = 10,9,7),results from white phosphorus and polysulfides; the TR spectra readily distinguish them. [Me,P(S)],P has a pyramidal structure with P-P bonds of 222.6 pm and a mean PPP angle of 105.7 0.s3 P,Se reacts with Sei- to give P,Sei- comprising P(v) in a P,Se chair ring which with Fe(CO) gives the complex [Fe2(CO),(PSe5),l2 -; the P(=Se)(Se-),(Se;) units bridge the two Fe atoms through both the two P=Se bonds and the isolated Se atoms.As,Seg-reacts with M(CO) to generate [M(CO),(As3Se,),12- while As,Seg- and M(CO) give [M(AsS~,),]~-.~~ Two isomers of each of cr-P,S,SeI and a-P,SSe,I have been identified by 31P and 71Se NMR spectroscopy; a systematic change in chemical shift and coupling constants was found for the series u-P,Ch,I (Ch = ~halcogen).~~ Irradiating Ph,P+ As,SCI in the presence of W(CO) gives Ph,PCl.4As4S and Ph,PWOCI,.thf; heating Cp”,o,(CO) (Cp” = EtMe,C,) and As,S gives both As and S substituted molybdenum complexes i.e. As,MoCp”(CO), As,Mo,Cp”,CO), and Cp”,o,X (X = S, 02S, os3).56 As,Cli -(X = C1 Br) reacts with Na,S to give As,SXg -(4) which upon further reaction is converted to SASS (5).57 (Ph,P),Sb3Cl, reacts with Na,S to give Ph,P+Sb,SCl; and (Ph,P+)2Sb2Cli- and with Na,S or Na,S to form (Ph,P+),- Sb,SClg-.58 (Bu‘NSiMe,),Se and SbCl give the cage-like derivative Se(SbCl),- (NBu‘) (6).s9 5 Organic Phosphorus Derivatives The application of transition metals in the synthesis of organophosphorus compounds has been reviewed.60 A reinvestigation of the structure of the tetracyanoethylene 52 E.G. Awere and J. Passmore J. Chem.Soc. Dalton Trans. 1992 1343; A. J. Bannister I. Lavender J. M. Rawson and W. Clegg ihid.,1992,859 N. Burford T. M. Parks B. W. Royan J. F. Richardson and P. S. White Can. J. Chem. 1992 70 703. 53 H. Falius. A. Schliephake. and D.Schomburg Z. Anorg. Allg. Chem. 1992 611. 141 L. Andrews. C. Thompson and M. C. Demarcq Inorg. Chem. 1992,31. 3173; M. Scheer and P. G. Jones J. Organomet. Chem. 1992 434 57. 54 J. Zhao W. T. Pennington. and J. W. Kolis. J. Chem. Soc. Chem. Comrnun. 1992,265;S. C. O’Neal W. T. Pennington and J. W. Kolis Inorg. Chem. 1992 31 888. 55 R. Blachnik P. Loennecke and B. W. Tattershall J. Chem. Soc.. Dalton Trans. 1992 3105. 56 B. Siewert and U. Miiller Z. Anorg. Allg. Chem.,1992,609,77; M. Gorzellik B. Nuber and M. L. Ziegler J. Organomet. Chem. 1992 429 153. ” B. Siewert and U. Muller Z. Anorg. Allg. Chem. 1992 609,82. B. Siewert and U. Miiller Z. Anorg. Ally. Chern.. 1992 609.89. ”) M. Bjorgvinsson H. W. Roesky F. Pauer and G. M. Sheldrick Chem. Ber. 1992 125 767.6o F. Mathey A. Marinetti and F. Mercier. SYNLETT 1992 363. N P As Sb and Bi adduct of Ph,P showed it to have the N-(heptacyanocyclopent-1-enyl)triphenylphos-phoranimine structure (equation l).61 The ability of phosphorus in organofluorophosphanes to behave both as an electrophile and a nucleophile determines both their disproportionation and reactions with aldehydes. Thus Bu;PF disproportionates via the P(III)-P(v)intermediate Bu",PF,(Bu") and reacts with PhCHO to give BU",OCHP~PF,(BU"),.~~ Reacting (Bu\P),PLi with BrCH,CH,Br gives Bu\PP=P(Br)(Bu'), which decomposes to a mixture of cyclophosphanes at 20 "C through the phosphinidene intermediate Bu',PP but gives the hexaphosphane [(Bu; P),P] at -20 "Cin toluene as yellow crystals.The structure indicates steric hindrance at the tertiary P atoms with angles of 115.7 ".63 1,2-Di-t-butyldiphosphine(7) disproportionates sequentially on warming to give first the triphosphane H,(Bu'P) (8) then the t-butylphosphinocyclotetraphosphane (9)which further reacts with (7)and (8)to lengthen the side chain thus giving (10).This further decomposes to (Bu'P) and the bicyclo[3.1 .O]hexaphosphane BukP (1 1) which itself yields BuiP (12) and Bu',P (13).64 Other polycyclophosphanes result from the thermolysis of Pr'PCl,/P,/Mg. 3,4,7,10,1l-Pr~-pentacyclo[7.4.0.0.~~60.5*1 30.87' 2]tridecaphosphane (14) (phosphorus skeleton only shown) occurs as two configurational isomers with different spacial arrangements at P-3 and is part of the Hittorf's phosphorus tubular structure.65 The tetraisopropyloctadecaphosphane(4) 8,14,16,18-tetraisopropyloctacyclo 10.4*90.5~70.6~'00.12~17]octadecaphosphane 113.2.1.0.2,'30.3*' (15) comprises P ,(5) and P,(3) structural units joined through a common P bridge and occurs as two configurational isomers with different spacial arrangements at P(8).66 Hexaiso- propyloctadecaphosphane(6) (1 6) also results from Pr'PCI,/P,/Mg and comprises " T.Mohan R. 0.Day and R. R. Holmes Inory. Chem. 1992 31. 2271. 62 J. Haenel G. Ohms and L. Riesel Z. Anory. Allg. Chem. 1992 607 161. 63 G. Fritz H. Goesmann and B. Mayer Z. Anorg. Ally. Chrm. 1992 607 26. 64 M. Baudler and H. Tschabunin Z. Anorg. Allg. Chem. 1992 617 31. 65 M. Baudler H. Jachow and K.-F. Tebbe. Z. Anory.Allg. Chem.. 1992,614 17. 66 M. Baudler W. Oehlert A. Kmieciak and A. Floruss Z. Anorg. Ally. Chern. 1992 611 43. D.A. Armitage 10 16 P11(5)and P,(5) units and is the first example of a heptacyclopolyphosphane 13.2.1.0.2,130.3*' 2.1 ']oc-5,7,8,14,16,18-hexaisopropylheptacyclo[ r0.4*90.6*'00.' tadecaphosphane. Compound (16) closely resembles (15) except that no bonding between P-5 and P-7.67Hexaisopropylicosaphosphane(6) occurs as a mixture of two constitutional isomers (17) and (1 8) in equal abundance; one 6,7,9,16,17,20-10.4980.5*100.'3*' hexaisopropyloctacyclo[ 10.8.0.0.23140.39' 80.'5*19]icosaphosphane,is a mixture of diastereomers (17) and the other 7,9,15,17,19,20-hexaisopropylocta-cyclo[14.2.1.15*80.2~'40.3*'20.4*100.6*1 'O."*' *]icosaphosphane a mixture of configur-ational isomers (18).68 54 20 19 '' M.Baudler H. Jachow and J. Hasenbach Z. Anorg. Allg. Chem. 1992 608 28. M. Baudler H. Jachow. W. Oehlert A. Kmieciak and A. Floruss. Z. Anorg. AUg. Chem.. 1992. 616 19. N P As Sh and Bi 61 6 Organoantimony and Bismuth Compounds The synthetic applications of organoantimony compounds have been reviewed.69 Bu‘SbMe can be made from SbCl in a one-pot synthesis from Bu‘MgC1 (-50 T) then MeMgBr (0“C)in ether and its thermal decomposition involves homolysis of the But-Sb bond and is unaffected by the addition of Me3Ga.” Condensing two moles of Ar,SbLiwith R,SbBr (R = Ph tolyl Me) gives the tristibanes R,Sb(SbAr,) with a trigonal bipyramidal structure and equatorial Ar,Sb The structure of Mes,Sb shows a trigonal pyramidal structure; Mes,Sb adopts a trans conformation with Sb-Sb bond lengths of 284.9~117.~~ Reducing Pr’SbBr with Mg gives (Pr’Sb) (x = 4 5) both of which are stable in solution at room temperature under an inert atmosphere but decompose on either warming or isolation as solids.The proton NMR spectrum of (Pr’Sb) supports the presence of both rings in solution.73 [(Me,Si),CHSb], however is stable as a solid and occurs as orange-red crystals that are air-stable even above their melting point (130 “C). The structural studies indicate a folded four-membered ring with trans substituents. Tristibines (R,Sb),SbR’ result as equilibria in solution from (R’Sb) and R,Sb (R = Ph R‘ = Et) and the tetrastibine (Ph,SbSbEt) also forms in solution.Cyclic stibines or distibines readily cleave the Se-Se or Te-Te bonds in diselenides or ditellurides to give the appropriate Sb-Se or Sb-Te deri~ative.~ An electron diffraction study of Me,Sb supports a trigonal bipyramidal structure. The first stibepine results from the appropriate stannepine with SbCl and can be alkylated at the Sb-Cl bond; these derivatives are thermally unstable reverting to the naphthalene and unidentified Sb derivatives in a few hours. The structure of the stibepine was confirmed by X-ray crystallography and is thermally more stable than the As analogue.’ Rh(1) catalyses the dearylation of Ar,Bi in the presence of CO to give the diarylketone; in methanol methyl benzoates Unlike most heavy metal azides Ar,Bi(N,) is reasonably thermally stable and oxidizes acyl isocyanates to give the N-arylcarbamoyl azide as the main product along with urea biuret and tetrazol- 5-0ne.~~ series of chiral mixed triaryl bismuthines results from the sulfonyl- A controlled selective iododearylation of o-Bu‘SO,C,H,Bitol, followed by successive acylati~n.~~ 1-Phenyl-2,5-dimethylbismole gives red-black crystals of the tetramethyldibismafer- rocene analogue upon dephenylation and reaction with FeCl,.A crystal-structure study shows a ferrocene-like array with Bi . . . Bi contacts of 368.8 pm close to that found between molecules of the green 2,2’,5,5’-tetramethylbibismole (365.9 6y Y.-Z. Huang Acc. Chem. Res. 1992. 25 182. ’(I R. W. Gedridge Jr. Orgunometullics 1991 11,967; D.S. Cao. C. H. Chen C. W. Hill S. H. Li. and G. B. Stringfellow J. Electron. Muter.. 1992 21 583 (Chem. Ah.. 1992 117 1 I1 715). ” N.K. Jha and P. Sharma J. Chem. Soc.. Chrm. Commun.. 1992 1447. ’’ M. Ates H. J. Breunig K. H. Ebert R. Kaller. M. Drager. and U. Rehrens %. Nururforsch.. Teil B 1992.47. 503. 73 M. Am H.J. Breunig K. Ebert S. Gulec R. Kaller and M. Drager. Oryunometullics 1992. 11. 145. 74 H. J. Breunig. S. Gulec. and R. Kaller Phosphorus. Sulphur. Silicon Relnr. Elm. 1992 67 33. ” C. Pulham A. Haaland A. Hammel K. Rypdal. H. P. Verne and H. V. Volden. Angrw. Chem. Inr. Ed. Enyl. 1992 31 1464; A. J. Ashe 111 L. Goossen. J. W. Kampf. and H. Konishi. ihid. 1992. 31 1642. 76 C.S. Cho T. Ohe 0.Itoh and S. Uemura J. Chem.Soc. Chem. Commun.. 1992 453. ’’ H. Suzuki C. Nakaya and Y. Matano. J. Chem. Res. (S) 1992 34. ’’ H. Suzuki and T. Murafuji. J. Chem. Soc.. Chem. Commun.. 1992. 1143. 7Y A. J. Ashe 111 J. W. Kampf. D. B. Puranik and S. M. Al-Taweel Oryunometullics 1992 11 2743. D.A. Armitage A range of dihydrodibenzo[b,e]bismines has been prepared for Bi(m) and Bi(v).80 Structure determinations suggest a transannular interaction between Bi and the heteroatom at position 5 providing the stabilization of CI-Bi and allyl-Bi bonds. The octasubstituted bistiboles and bibismoles result from the appropriate zirconacyclopen- tadiene with PhSbCI, PhBiBr, or BiBr, followed by reductive coupling. The bibis- moles are thermochroic but not the stiboles and in contrast with the less substituted 2,2’,5,5’-tetramethylbipnictides which are thermochroic for both Sb and Bi.81 7 Multiple Bonds to Carbon Further analogies between P=C and C=C double bonds have been reviewed as has the oligomerization of phosphaalkynes to phosphacubanes.82 The first example of a complex of a cyaphide (19) (phosphorus analogue of cyanide) has been shown to result from the 2-phosphavinylplatinum derivative (20) and successive Pd(0) and Pt(0) complex-mediated reactions.A structure determination shows a bridged cyaphide with a C-P bond length (166.6 pm) longer than in the parent phosphaalkynes and similar to that in the q2-phosphaalkyne complexes (equation 2).83 c1 ClI#tC(Cl)=PAr* pdL4-ClLPdAr* + ClkPtC=P LPtLI PL C24 (2) (20) L = Et3P p PtL (1 9) Fluorine substituted phosphaalkenes result from the gas-phase thermol-ysis of stannyl phosphines Me,SnP(R)NMe (R = CF or C,F,) and readily oligomerize or undergo [2 + 41 cycloaddition to ~yclopentadiene.~~ CF,P=CXF (X = F OR) give phosphorus ylides Me,P=C(X)P(F)CF, with PMe,; condensing Ph,PCH,R+Br-with Ph,P=CRPCI gives the phosphenium chlorides Ph,P=CRPCR=PPh (R =aryl) which also result from Ph,P=CRSiMe and PCI,.Na,X (X = S Se) and Ph,P=C(Ph)PCI give the monomeric Ph,P=C(Ph)PX with P=X multiple bonds.85 The phosphorus ylide H,C=PH has been shown to be stable in the gas phase; Bu\CIP=CPh occurs as yellow crystals containing three independent molecules in the unit cell with the P-Cl bond length increasing with increased eclipsing of the p-orbital in the ylide carbon atom with the P-Cl bond.AICI removes chloride to give the methylenephosphonium cation.86 (E,E)-and (E,Z)-3,4-(Ar*phosphinidene),cy-clobutene can be prepared by desilylating the 1,2-bissilylcyclobutene or thermally no H. Suzuki T. Murafuji and N. Azuma J. Chem. Soc. Perkin Truns. I 1992 1593. ni R. E. v. H. Spence D. P. Hsu and S. L. Buchwaid. Orqunometullics 1992. 11 3492. ” F. Mathey Acc. Chem. Res. 1992 25 90 M. Regitz. Bull. Soc. Chim. Belq. 1992 101 359. n3 H. Jun V.G. Young Jr. and R. J. Angelici. J. Am. Chem. Soc.. 1992 114. 10064. n4 J. Grobe D. Le Van S. Martin and J. Szameitat Z. Nuturfi,r.sch. Teil B 1992 47 321. n5 J. Grobe D. Le Van U. Althoff and G. Lange Chem. Ber. 1992,125,567;A. Schmidpeter and G.Jochern Tetrahedron Lett.1992 33 471. n6 H. Keck W. Kuchen P. Tornrnes J. K. Terlouw and T. Wong Anyew. Chem. Int. Ed. Engl. 1992,31,86; H. Grutzmacher and H. Pritzkow. ihid. 1992 31 99. N P As Sb and Bi isomerizing Ar* P=C=CH-CH=C=PAr* the bissilyl (E,E) derivative readily chelates to an Mo(CO) unit.'7 The aminophosphacyclobutadiene complex (CO),Ni(~'-p2-(Pr~NCP),)NI(CO), has one phosphorus atom of the four-membered ring complexing with both Ni(CO) residues; the C-P bonds are longer at this P atom (185 pm) than at the other uncomplexed P atom (178 pm). Molecular orbital calculations have been used to substantiate the photoelectron spectrum of the diphosphacyclobutadiene complex of Fe(CO) and CpCo residues.'* The 1A5,3L5-diphosphete [(Me,N),PCH] gives complexes with GeCI, SnCl, and W(CO), in all cases bonding occurs at carbon to give the zwitterion structure (21).2-Hetero- 1A5,3i5-diphosphabenzenes(22)complex with Mo(CO) residues through the P-X-P unit (equation 3).89 Me I (Ph,P),Pd dechlorinates 2,4,6-Bu',C,H2P=CCI to give the corresponding phos- phaalkyne quantitatively. The microwave spectrum of P-CCl shows a C-P bond length of 155.4pm." The molecular structure of BUT-P shows an almost linear skeleton with the CFP bond 154.2 pm while the signs of all the coupling constants to phosphorus in the ' NMR spectrum are positive." The spirocyclotrimerization of Bu'C-P in the presence of AICI gibes a betaine structure (23) which with DMSO to remove AICI, followed by a homo-Diels-Alder reaction with Bu'CEP gives the tetraphosphaheterocycle (24) (equation 4) isomeric with the tetraphosphacubane analogue .92 Lithiation of Cp,ZrCI followed by treatment with Bu'C-P gives the correspond- ing diphosphazirconabicycles which with C,Cl yield the tetraphosphacubane (Bu'CP),.This complexes with Fe,(CO), and subsequent demetallation leads to the diphosphete complex (Bu'CP),Fe(CO) and (Bu'P),F~(CO),.'~ '' K. Toyota. K. Tashiro M. Yoshifuji and S. Nagase Bull. Chem. SOC.Jpn 1992,65 2297; K. Toyota K. Tashiro M. Yoshifuji I. Miyahara A. Hayashi and K. Hirotsu J. Organomet. Chem. 1992 431 C35. 88 J. Grobe D. Le Van M. Hegemann B. Krebs and M. Lage Angew. Chem. Int. Ed. Engl. 1992,31.95;R. Gleiter I. Hyla-Kryspin P. Binger and M. Regitz Organometallics.1992 11 177. H9 E. Fluck M. Spahn G. Heckmann and H. Borrmann Z. Anorg. Allg. Chem. 1992,612,56;S. F. Gamper and H. Schmidbaur Organometallics 1992 11 2863. yo V. D. Romanenko M. Sanchez T. V. Sarina M. R. Mazieres and R. Wolf Tetrahedron Lett. 1992 33 2981; S. Firth S. Khalaf and H. W. Kroto J. Chem. Soc. Faraday Trans. 1992 88 3393. 91 A. N. Chernega M. Y. Antipin Y.T. Struchkov M. F. Meidine and J. F. Nixon. Hererout. Chem. 1991.2 665; B. Wrackmeyer Z. Nuturjbrsch. Teil B 1992. 47 437. 92 B. Breit U. Bergstrasser G. Maas and M. Regitz Angew. Chem. Inr. Ed. Engl. 1992 31 1055. 93 T. Wettling B. Geissler R. Schneider S. Barth P. Binger and M. Regitz. Angew. Chem. fnt. Ed. Engl. 1992 31 758; M. Birkel J. Schulz. U. Bergstrasser and M. Regitz ihid.1992 31 879. D.A. Arrnituge BU‘ ‘B u‘ (23) (24) Radical catalysed ring expansion of 1,2-ArT- 1,2-diphosphaspirocyclopentanegives the phosphacyclobutane (25),its P-oxide and the 1,4-diphosphanorbornadiene(26).94 Coupling CIP=C(R)SiMe with cyclopropenylidene phosphanes gives the new class of phosphapolyenes (27) with 2 ge~metry.’~ 8 Pictogen-Pnictogen Multiple Bonds and Catenation The diphosphenes Cp*P=PCp* and Cp*P=PAr* react with diazomethanes to give diphosphiranes via a [2 + 3]cycloadduct intermediate. Cp*As=PAr* behaves simi- larly to give products with the bulky substituents trans ~rientated.~~ A range of ql-and q2-complexes results from such diph~sphenes,~’ while reaction with the carbonyl anions Cp*M(CO); gives Cp*M(CO),P=PAr* and the tetraphosphabicyclobutane CPTP,.~~ Coupling (CO),Mn(H)PPh,H with Ar*AsCl using BuLi gives the novel manganacyclopropane (28)which has a short P-As bond length of 229 pm (equation 5).99 The phosphinidene complexes Cp(CO),M=PMes[M’(CO),Cp] (M = M’ = Mo W) add sulfur or selenium across the M=P double bond to give three-membered y4 C.Garot.G. Moghadam. J. P. Declercq. A. Dubourg and M. Konig .4ngew. Chem.,Inr. Ed. Engl. 1992 31. 625. 95 B. Breit. H. Mernmesheimer R. Boese. and M. Regitz. Chem. Ber. 1992 125. 729. L)6 P. Jutri and S. Opiela. Z. Anorg. AIlg. Chem.. 1992 610. 75. ’’ P. Jutzi. U. Meyer. S. Opiela. B. Neurnann and H.-G. Stammler. J. Organomer. Chem. 1992. 439 279; K. B. Dillon and H. P. Goodwin ihid.. 1992. 429. 169. ” P.Jutzi and S. Opiela J. Organomet. Chem. 1992. 431 C29. 9Y E. Lindner. P. Fisahn. R. Fawzi. and M. Steirnann Z. Nufur-orsch..TZ! B. 1992. 47 1798. N P As Sb and Bi phosphametallocycles. * O0 The reaction of the diphosphenyl complex Cp*(CO),FeP= PMes* with RC(O)N=NC(O)R gives the oxadiazaphospholene (29) through [l + 41 cycloaddition; A '-1,2,4-triazoline-3,5-diones give the first 1,2-diaza-3,4-diphos-phetidines (30) in benzene but in ether give the tetraphosphacyclododecadienes (31).' An excess of N-methylmaleimide induces P=P cleavage to give the phosphine (32) with succinimidyl and bicyclo[3.1 .O]-1-aza-4-phosphahexane-2,6-dion-3-y1 sub-stituents.lo2 0 9 Phosphorus-substituted Rings Phosphorus-substituted eight-membered rings have been reviewed.lo3 Calculations suggest remarkable stability for 1-fluoro-1H-phosphirene; the phos- phaC3lradialene (33) results from the 1-phospha- 1,2,3-butatriene (34) and dich- lorocarbene (equation 6).lo4 Calculated and observed diphosphirane dipole moments both indicate trans-isomers when large substituents are present but predict cis-isomers for less bulky groups. Addition of carbene to the rr-system of diphosphenes gives the monohalo diphos- phirane which can be ring opened photolytically to give 1,3-diphosphapropenes which with RMgX yield substituted 1,3-diphosphapropenes and dienes. Dihalodiphos- phiranes give 1,3-dipho~phallenes.'~~ (Me,Si),NLi dehydrohalogenates PhCH,-I"" U.-A. Hirth W. Malisch and H. Kab J. Organomet. Chem. 1992,439 C20.lo' L. Weber H. Bastian A. Miiller and H. Bogge 2.Naturforsch.. Teil B. 1992,47,23 1;L. Weber H. Bastian R. Boese H.-G. Stammler and B. Neumann Chem. Ber. 1992. 25 1821. lo2 L. Weber M. Frebel and R. Boese 2. Anorg. Ally. Chem. 1992,607. 139. lo3 R. P. Arshinova Phosphorus Sulphur Silicon Relat. Elem. 1992 68 155. '04 M. T. Nguyen H. Vansweevelt and L.G. Vanquickenborne Chem. Ber. 1992 125,923; I. Miyahara A. Hayashi K. Hirotsu M. Yoshifuji H. Yoshimura and K. Toyota Polyhedron 1992. 11. 385. C. Tachon M. Gouygou M. Kiinig M. J. Herve D. Gonbeau and G. Pfister-Guillouzo Inorg. Chem. 1992 31 2414; J.-P. Fayet D. Mermillod-Blardet C. Tachon G. Etemad-Moghadam and M. Konig. Can. J. Chem. 1992 70 2834; R. El-Ouatib C. Garot. G. Etemad-Moghadam and M. Konig J.Organomet. Chem. 1992. 436 169. D.A. Armitage (33) (Et,N)P(F)=CHPh to give the 1,i5,3i5-diphosphete as the cis isomer and the phosphirane (35) (equation 7).lo6 Photolysing Ar*P(N,) gives the phosphinidene which rearranges to the phosphain- dane through C-H insertion (equation 8).' O7 Thermolysing 1-benzyl- 1-phosphadihyd-roazulene in the presence of Pt/C gives 1 -phosphaazulene while the 2-benzyl derivative results on heating in xylene.lo8 Calculations on the aromaticity of phosphorus analogues of the cyclopentadienyl anion show PC,H to retain 86% of the aromaticity ofC,H and remarkably P; to be as aromatic as C,H .lo9 Mass spectra support the existence of the phosphatropylium and phosphabenzylium ions formed from benzene and P' (from PI3).ll0 Treating P,C,Bu and P,C,Bu\H with an excess of sulfur gives mono- and trisulfur adducts respectively.The trisulfide adds ethanol (equation 9).l1 The tetraphosphafulvalene dianions (36) (isoelectronic with tetrathiafulvalene dications) react with sulfur to give the dithiophosphinate derivative (37) or with q5-CpFe(q6-xylene)+ to give the ferrocene-like derivative (38) which further chelates to a Mo(CO) residue (Scheme l).' ' Penta- and hexaphosphaferrocenes coordinate to W(CO) and Ru,(CO), residues. The coupling of (38) with glutamoyl chloride and Io6 E. Fluck R. Braun A. Miiller and H. Bogge Z. Anorg. Allg. Chem. 1992 609 99. lo' A.H. Cowley F. Gabbai R. Schluter and D. Atwood J. Am. Chem. Soc. 1992. 114 3142. lo' G. Mark1 and J. Reindl Tetrahedron Lett.1992 33 5495. lo' E. J. P. Malar J. Org. Chem. 1992 57 3694. 'lo C.A. Muedas D. Schroeder D. Suelzle and H. Schwarz J. Am. Chem. Soc. 1992 114 7582. 'I1 R. Bartsch P. B. Hitchcock and J. F. Nixon J. Organomet. Chem. 1992. 433 C11. N. Maigret L. Ricard C. Charrier. and F. Mathey Angew. Chem. Int. Ed. Engl. 1992 31 1031. N P As Sh and Bi subsequent reduction of the product gives a dianion which with (p-xylene),Fe2 + gives the first phosphorus analogue of ferrocenophane.' ' (q6-1.4-MezC&)FeCp+ (38) Scheme 1 12.5,3A5-Diphosphole derivatives result from (Ph,P)2CH and propargyl bromides while the 1A5,52.5-diphosphocin (39) results from the treatment of diphosphocanium dichloride with strong base. It was found to have a tub-like structure with two methallylic fragments connected through i5-phosphorus atoms which disrupt the total n-delocalization.' l4 Coupling BUT-P with diphenylketene at 100°C leads ultimately to the 1-phosphanaphthalene (40),while the 2-iodophosphinine o-complex of W(CO) can be functionalized at position 2.' The Ni(0) complex of phosphabenzene (ql-Ph 11.3 R.Bartsch A.Gelessus P. B. Hitchcock and J. F. Nixon. J. Oryunomer. Chem. 1992 430. C10; M. L. Sierra N. Maigret C. Charrier L. Ricard and F. Mathey Oryunometallics 1992 11 459. I I4 A. Schrnidpeter. J. Stocker and K. Karaghiosoff Chem. Ber. 1992 125 67; H. Schrnidbaur and S. F. Garnper. Orqanometallics 1992 11 986. 115 G. Markl A. Kallrnunzer H. Noth and K. Pohlrnann Tetrahedron Lett.1992,33 1597; H. T. Teunissen and F. Bickelhaupt ihrd. 1992 33 3537. D.A. Armitage C,H,P),Ni gives orange air-stable crystals with S symmetry and Ni-P bonds that are almost as short (212.7 pm) as those in the PF complex (210 to 21 1 pm).' l6 10 Nitrogen The protonation of dinitrogen has been reviewed along with nitrido complexes of transition metals.' ' Calculations regarding the stability of pentazole and its derivatives have been found to be consistent with the experimentally determined stabilizing effect of electron withdrawing substituents such as p-dimethylaminophenyl. Of the six isomers ofN considered calculations show the diazide to be the most stable with the Kekule and Dewar benzene/benzvalene forms being less stable.' l8 The nitridoferrate(I1) and cobaltate(1) anions FeN:- and CON; -,which result from the reductive thermolysis of Sr,N with Fe and Co respectively at 850"C possess triatomic linear structures.Heating Li/Ba with N in Ni crucibles gives a nitride with infinite Ni(N,) linear chains. Upon cooling a solution of barium and nitrogen in liquid sodium black needles of NaBa,N comprising face sharing Ba,N octahedra form. This subnitride provides an extension of alkali metal suboxide-like chemistry.' l9 Condensing Co,N(CO); with Co(CO) gives Co,N(CO):; which like its Rh analogue possesses a square-faced capped trigonal prism structure with nitrogen in the centre of the trigonal prism. Rh,N(CO), pyrolyses to the large cluster Rh,,N,(CO),,(p-CO)~~ which encloses two Rh and four N atoms with each nitrogen atom connected to five Rh atoms.'20 Cp:Sm(thf) cleaves the N-N bond of PhNHNHPh to give [CpfSm(NHPh),],.This also forms from reaction between [CpfSm(p-H)] and PhNH2.12' CpTiC1,NHBu' shows multiple-bond character in the Ti-N bond while Cp:Ta(=NPh)H has a Ta-N bond of length between that of double and triple.', The chloronitreno complex K(crown)WF,(=NCl) shows an almost linear W=NC1 group with a short W-N bond length of 172.4pm; NEEMo(OBu') is methylated by Me,Zn to give tetrameric [N~MoMe2(0Bu')~~(4-Bu'C,H,N)], with linear Mo=N-Mo bridges.' 23 NETcCl; gives cis-[TcN(Cl)L,] + PF (41) with chelating diphosphines and o-phen. With S,Cl, (41) L = o-phen gives the thionitrosyl cis-[Tc(NS)Cl(o-phen),] +PF .I2 Reacting CpK with TcI(NAr) gives q'-CpTc(NAr) .'2s '16 C.Elschenbroich M. Nowotny A. Behrendt. W. Massa and S. Wocadlo Angew. Chem. Inr. Ed. Engl. 1992 31 1343. 'I7 G. J. Leigh Acc. Chem. Res. 1992,25 177; K. Dehnicke and J. Strahle Angew. Chem.,Int. Ed. Engl. 1992 31 955. 1 I8 K. F. Ferris and R. J. Bartlett J. Am. Chem. Soc.. 1992 114. 8302; R. Engelke J. Phys. Chem. 1992 96 10 789. 'lYP. Hohn and R. Kniep Z. Narurforsch. Ted B 1992.47,477; 434; A. Gudat R. Kniep and A. Rabenau Z. Anorg. Ally. Chem. 1992,607,s; P. E. Rauch and A. Simon Angew. Chern. Int. Ed. Engl. 1992,31 1520. I20 G. Ciani N. Masciocchi A. Sironi A. Fumagalli and S. Martinengo Inorg. Chem. 1992 31 331; S. Martinengo G. Ciani. and A. Sironi. J. Chem. Soc.. Chem. Commun. 1992 1405. I21 W.J. Evans G. Kociok-Kohn V. S. Leong and J. W. Ziller Inorg. Chem. 1992 31. 3592. D. M. Giolando K. Kirschbaum L. J. Graves and U. Bolle Inory. Chem.. 1992 31 3887; G. Parkin A. van Asselt D. J. Leahy. L. Whinnery N.G. Hun R. W. Quan. L. M. Henling. W. P. Schaefer B.D. Santarsiero. and J. E. Bercaw Inorg. Chem.. 1992 31. 82. W. A. Herrmann S. Bogdanovic. J. Behm and M. Denk J. Orgunomet. Chem.. 1992,430 C33; H. Stenger K. Dehnicke. and W. Hiller Z. Nuturfbrsch.. Teil B 1992 47 1054. C. M. Archer J. R. Dilworth D. V. Griffiths. M. McPartlin and J. D. Kelly J. Chrm. SOL..,Dalton Trans. 1992 183; M. J. Clarke and J. Lu Inory. Chem. 1992 31. 2476; M. J. Clarke and J. Lu. J. Chem. Soc. Dalton Trans. 1992 1243. lZ5 A.K. Burrell and J.C. Bryan. Orgunomrtallics 1992 11 3501.N P As Sb and Bi The cis and trans isomers of W(N,),(PMe,Ph) have been separated.'26 1,2- Dimethylhydrazine was shown to complex as a four-electron donating diazene ligand to W(IV)(equation 10); the structure offuc-[(OC),(DPPE)W=NNMe,] shows the nitrogen ligand to bond as a Fischer carbene with an N-N bond length of 121 pm.',' ReOCl,( PPh,) gives a range of five- and six-coordinate bis(hydrazid0) complexes with MePhNNH, the hydrazide ligands being cis.' 28 -CH NMe Cp*WMei + MeNHNHMe -$-Cp*Me,W< I NMe Thermolysis of CpMo(NO)(CH,CMe,) gives the bimetallic neopentyl bridged complex CpMo(NO)(p-q'-q'-NO)(pCHCMe,)(CpMo=CHCMe,) in which one NO is terminal to one Mo atom and n-bonds to the other.'29 The structure of N,O supports a nitrosyl nitrite structure with a long N-N bond length of 189.1 pm (bond order 0.2) with N-0 being 112 pm long at the nitrosyl group and 121 pm long at the nitrite group.'30 11 Phosphorus-Nitrogen Compounds Phosphorus nitrides are described as the Cinderella of phosphorus chemistry.I3' Few molecules containing only phosphorus and nitrogen exist but recently the anions PNi-and P,N:g- were reported and the pyrolysis of ZnC1 with NH,Cl and (NPCI,) gives Zn,(P,,N2,)Cl containing the P 2N:$- anion which has a sodalite structure and a chloride ion encapsulated tetrahedrally by zinc ions.' 32 Ammonolysis of P,N gives HPN as a 3D framework of corner-sharing PN tetrahedra with hydrogen bonded to half of the nitrogen atoms.'33 The phosphatrane complexes XP(MeNCH,CH,),N [X = H + CS, MeS(S)C+ PhN=C(SMe)' Pt(iI) Hg(ir) or R~(I)]show a shortening of the bridge-head-bridgehead contact from 333 pm (Pt) to 196.7 pm (H' ) with a widening of the NPN angle from 104.5'-to 119.6 .I3 Calculations support a high degree of aromaticity for azaphospholes containing a2,j.3-phosphorus atoms but not for those containing a3,i3-phosphorus atoms.This applies to 1,3-aza2- 172,4-diaza- arid 1.2,3,4-trizazaphospholes. I 35 PrlNC-N under-goes [3 + 2lcycloaddition with CF3CH=N2 or MeO,CCH=N to give both the 1,2,3- and 1,2,4-diazaphospholes the structure of the latter suggesting n-delocalization T.A. George. J.R. D. DeBord. B. B. Kaul. C. J. Pickett. and D.J. Rose. Inorg. Chrm.. 1997. 31. 1295. T. E. Glassman M. G.Vale and R.R.Schrock.Inorg. Chem.. 1992.31. 1985 B. A. Arndtsen. T. K. Schoch. and L. McElwee-White. J. Am. Chem. Soc. 1992. 114. 7041. J. R. Dilworth. P. Jobanputra. S.J. Parrott R. M. Thompson D. C. Povey. and J. A. Zubieta. Polyhedron. 1592. 11. 147. P. Legzdins. S.J. Rettig. and J. E. Veltheer. J. Am. Chrm. Sot,. 1992. 114. 6922. ''" A. Simon. J. Horakh. A. Obermeyer and H. Borrmann. .4ngrw. Chcrn.. lnr. Ed. Engl.. 1992. 31. 301 13' O.J. Scherer Angew. Chem.. In[. Ed. Engl.. 1992. 31. 170. w. Schnick and J. Lucke. Angrw. Chrri.,In!. Ed. Engl.. 1992. 31. 213. 13' w. Schnick and J. Lucke. Z. Anorg. Ar'ly. Chem.. 1992. 610. 121. J. S.Tang M. A. H. Lararnay. V. Young. S. Ringrose. R. A. Jacobson. and J.G. Verkade .I Am. C~ICW. Soc. 1992. 114 3129.L. Nyulaszi. T. Veszpremi. J. Refly. B. Burkhardt. and M. RegItz. J. Am. Chem. So<,.. 1992. 114 9080. 70 D.A. Armitage with P-C bond lengths of 174 to 177 pm.' 36 1,3,5-Triaza-2,4-diphospha-penta-1,4-dienes Ar*N=PNRP=NAr* exist as S-type 'exo-endo' conformers in the solid and readily chelate to metal carbonyl residues through the two phosphorus atoms.13' Adding Ar*N-P+ to alkynes gives 2-A3-phosphachinolines (42) in which the P-N bond and P-C bonds are 163 and 175pm in length (equation ll).13* The Bu' R azadiphos-phane (Pr\N),PN reacts photochemically with bis(imin0)phosphoranes after N elimination to give diazaphosphetes e.g. (43) and (44) (equation 12).139 (44) (12) (43) Cyclodiphos-phazanes (RNPX) readily complex as monodentate ligands with metal carbonyl residues through P-coordination.40 12 Phosphorus and Arsenic MCl (M = P As Sb Bi) forms the chelated dichlorides 2,6-(Me,N),C6H,MC1 with Li[2,6-(Me,N),C6H,]. The Sb derivative has a distorted square pyramidal struc- ture.14' The preparation LiP(H)(2,4,6-Bu\C,H2) also gives [Li(2,4,6-Bu\C6H,)LiP(H)(2,4,6-Bu\C6H2)], an eight-membered ring with two two-coordi- nate Li atoms with short Li-C(ary1) o-bonds and two involving a Li-P o-bond and n-coordination with an aryl ring. 142 Coupling silylated phosphinoboranes with Pr',NBCl gives the trigonal bipyramidal P,(BNPr',),. The B-P analogue of the pentadienyl cations PhB(PMesBMes,), shows '36 J. Grobe D. Le Van M. Hegemann. B. Krebs and M. Lage Chem. Ber. 1992 125 411. 13' R.Detsch E. Niecke M. Nieger and F. Reichert. Chem. Ber. 1992 125 321. G. David E. Niecke and M. Nieger Terrahedron Lett. 1992 2335. 13' J. Boske E. Niecke B. Krebs M. Lage. and G. Henkel Chem. Ber. 1992. 125 2631. I4O M. S. Balakrishna and S.S. Krishnamurthy J. Orgunomet. Chem. 1992 424 243; V. S. Reddy S. S. Krishnamurthy and M. Nethaji ibid.,1992,438 99; T. K. Prakasha S. S. Krishnamurthy S. E. Davies M. F. Meidine and J. F. Nixon ihid. 1992 438 241. 14' D.A.Atwood A. H. Cowley and J. Ruiz Inorg. Chim.Acta 1992. 198 200 271. 142 S. Kurz and E. Hey-Hawkins Orgunometullics 1992. 11 2729. N P As Sb and Bi 71 dynamic behaviour in solution and B-P bond lengths of 186.4pm suggesting n-bonding. 143 The phosphides LiP[C(O)R] (R = cyclohexyl or adamantyl) on protonation give phosphines which show strong temperature-dependent keto-enol equilibria.The adamantyl derivatives crystallize from benzene as the enol tautomer with almost equal P-C bonds (180pm). The reaction of (dme)LiPH with HC0,Et gives dimeric HP=CHOLi as a mixture of E and 2 isomers whereas the reaction with (MeO),CO gives the methylidynephosphine (dme),LiOC-P with P-C 155.5 pm long and C-0 119.8pm 10ng.l~~ Coupling LiAsH with Bu'COCl gives LiAs(COBu') which reacts with acid to give the diarsine as the keto isomer.145 (Et,N),P reductively couples [Cl,PCH,] and CF,Br to give the trifluoromethyl substituted diphosphine; (Me,N),P adds para to pyrylium salts whereas they are ring opened by (Me,N),Sb (equation 13).'46 The diarsadigalletane [Bu'GaAsC~,H,(CH,NMe,),] results from (Bu'GaCI,) and Li,AsC,H,(CH,NMe,) in ether the structure showing amino coordination to each Ga atom in a Ga,As ring.14' (CF,),AsN has C,ssymmetry with azide trans to the CAsC bise~t0r.l~~ 13 Antimony and Bismuth A range of dithiolate complexes (L,Sb),CH and (LMe,Sb),O of Sb(II1) and Sb(v) has been made where L is R,NCS; ROCS; or (RO),PS .149 Ph,SbS,P(OPr') shows weak association (Sb ...S = 320 and 380 prn).l5' Sb(rr1) carboxylates Ar,SbOCOR are bridged polymers; chelated Sb(v) complexes R,SbL;+ have been made.151 Ph,Sb(oxalate) occurs as Ph4Sb+ Ph,Sb(oxalate); Bu'OOH oxidizes Ph,SbX (X = F or SCN) to the tetramer (Ph,SbXO), which has Ph,SbX,O units coupled to each Sb of an Sb,O four-membered ring.153 Two moles of hexafluorocumyl alcohol react with two moles of SbCl to give a 14' D.Dou. G. L. Wood E. Duesler R. T. Paine and H. Noth fnorg. Chem. 1992.31.3756; D. C. Pestana and P. P. Power Organometallics 1992 11 93. 144 G. Becker M. Schmidt W. Schwarz and M. Westerhausen Z. Anorg. Allg. Chem.. 1992 608 33; G. Becker W. Schwarz N. Seidler and M. Westerhausen ihid. 1992 612 72. 145 G. Becker M. Schmidt and M. Westerhausen Z. Anorg. Allg. Chem.. 1992 607. 101. 146 L. D. Field and M. P. Wilkinson Tetrahedron Lett. 1992 33 7601 ; Y. Madaule M. Ramarohetra and J.G. Wolf ibid.. 1992 33 1737. 14' D. A. Atwood A. H. Cowley R. A. Jones. and M. A. Mardones J. Orgunornet. Chern. 1992 439 C33. 14' H.G. Ang W. L. Kwik Y. W. Lee S. Liedle and H. Oberhammer J. Mol.Struct. 1992 268. 389. 149 S. Kraft and M. Wieber Z. Anorg. Ally. Chem. 1992 607 164. 153. lS0 C. Silvestru M. Curtui I. Haiduc M. J. Begley and D. B. Sowerby. J. Orgunornet. Chem. 1992,426 49. 15' P. Raj and A. K. Aggarwal Synth. React. fnorg. Met.-Org. Chem.. 1992 22 509 543. P. L. Millington and D. B. Sowerby J. Chem. Soc. Dalton Trans. 1992. 1199. I53 G. E. Forster. G. Southerington and D. B. Sowerby Phosphorus,Sulphur Silicon Rulut. Elern. 1992.64.55. D.A. Armitage 10-Sb-4-type antimonyate complex showing a distorted trigonal bipyramidal struc- ture and bismuth (111) with one hexafluorocumyl alcoxy group and an intramolecular coordinating o-aminomethylphenyl group show edge inversion at bismuth.' 54 Bis-muth(m) gives complexes bridged dimers with (CF,),CHO and C,F,O as the bridging groups; heating Ph,Bi under reflux with C,F,OH in thf gives the cluster [Bi,(p3- + 0,)(p3-OC,F,)]3 [Bi(OC6F5),],.2thf.' 55 Bi(OAc) reacts with iodine and alkenes in anhydrous acetic acid to give the iodoacetates but iodohydrins and ethers result if water is present.'56 Applying high-pressure 0 to Ag,O/Bi,O gives black crystals of Ag,,Bi,O,,.This change in oxidation state of Bi from (111) to (v) is the result of a pressure-induced shift of oxygen atoms delocalizing the 6s2 valence electrons.' 57 154 K. Akiba H. Nakata Y. Yamainoto and S. Kojima Chem.Lett. 1992,1559; Y. Yamamoto X. Chen and K. Akiba J. Am. Chem. SOC. 1992 114 7906. 155 C. M. Jones M. D. Burkart and K. H. Whitmire Angew. Chem. Int.Ed. Engl. 1992,31,451. C. M. Jones M. D. Burkart and K. H. Whitmire J. Chem. Soc. Chem. Commun.. 1992. 1638. 15' R. W. Trainor. G.B. Deacon W. R. Jackson and N. Giunta Ausr. J. Chrm. 1992. 45 265. 15' M. Bortz and M. Jansen Z. Anorg. Allg. Chem. 1992. 612 113.

ISSN:0260-1818    

DOI:10.1039/IC9928900053

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

6 0 S Se and Te By J. D. WOOLLINS Department of Chemistry Imperial College London SW7 2A Y UK This review deals with developments in late 1991 and 1992over a broad range of Group 16 chemistry but does not make any attempt to include solid state materials such as oxides or sulfides which are dealt with elsewhere. There have been useful reviews on C-S1 ,Se-N/Te-N '-' and organodisulfide complexe~.~ Oxidants and mechanisms continue to provoke interest. The mechanism of the formation of singlet oxygen from the singlet and triplet states of 9,lO-dicyanoan- thracene (DCA) has been shown' to proceed by quenching of 30,by 'DCA. It was proposed that oxygen quenching of the benzophenone triplet state involves exciplex formation6 on the basis of variable temperature studies.The oxidation of ferrous ions by ozone (pH 0-2) has been studied' by stopped flow spectrophotometry and it was suggested that one of the intermediates is the ferry1 ion Fe02 + . Related to this a new blue paramagnetic p-0,-dirhodium(trispyridine) complex has been postulated on the basis of ESR UV/Vis spectrometry and its reaction chemistry.8 Pathways for water oxidation catalysed by [(bpy),Ru(OH,)],04+ have been prop~sed.~ The symmetric Ru-0-Ru stretch in this complex (as well as the other dimers containing ruthenium in higher oxidation states) was observed by resonance Raman for normal and l80 labelled material which allowed the Ru-0-Ru angle to be estimated. Other labelling experiments suggest that one pathway of the oxidation involves transfer of oxygen from an aqua ligand.An overall mechanism was proposed; the bridging oxygen is believed to be especially influential in controlling/activating the reactant water molecules via hydrogen bond formation. Kinetic studies of the MnO /RuO water oxidation system have also been reported;" the solid RuO behaves as microelectrodes for electron transfer between the two highly irreversible processes i.e. oxidation of 0 to water and reduction of MnO to Mn". Related to the above work is the report" of the spontaneous fixation of CO in air according to equation 1 ' 'The Chemistry of Inorganic Ring Systems' ed. Ralf Steudel Elsevier Amsterdam 1992. M. Bjoergvinsson and H. W. Roesky Pollhedron 1991 10 2353. P. F. Kelly A.M. Z. Slawin D. J. Williams and J.D. Woollins Chem. Soc. Rec.. 1992 21 245. D. Carrillo Coord. Chem. Rev. 1992 119 137. R.C. Kanner and C. S. Foote J. Am. Chem. Soc. 1992 114 678; 682. ' A. J. McLean and M. A. Rodgers. J. Am. Chem. Soc. 1992 114 3145. ' T. Logager J. Holcman K. Sehested and T. Pedersen Inory. Chem. 1992 31 3523. ' R.D. Gillard Polyhedron 1992 11 1737. J.K. Hurst J. Zhou and Y. Lei Inorg. Cliem. 1992 31 1010. A. Mills P. Douglas and T. Russel J. Chem. Soc.. Dalton Truns.. 1992. 1059. l1 T.Tanase S. Nitta S. Yoshikawa K. Kobayashi T. Sakurai. and S. Yano. Inory. Chem. 1992.31 1058. 73 J. D.Woollins [N,N-Me,en = N,N-dimethylethylene diamine]. The X-ray crystal structure of (1 ) reveals all three nickels to be in octahedral environments with the carbonate behaving as a bidentate ligand surrounded by an unusual planar hydrogen bonding network that may be responsible for the fixation of CO in this case; for related complexes containing bidentate en derivates no similar fixation was seen.Ruthenium compounds are still being developed as synthetic reagents. Thus [Ru(edta)NO)] was prepared and + characterized crystallographically. ' It contains five coordinate EDTA linear NO and catalyses the oxidation of hex-1-ene to hexan-2-one and cyclic olefins to epoxides without the need for a co-catalyst. 0x0-complexes particularly those containing bridging oxygen atoms have been studied by a number of groups. For example the structures of [TiCI(p-O)(12- crown-4),][SbC1,],~2CH2C12 (2)' and [Ti(THPED)] (3)14 (THPED = N,N'-tetrakis-(2-hydroxypropyl)ethylenediamine)both contain Ti,O cores (Ti-0-Ti 100.3(2) 112.2(2) and 0-Ti-0 79.7(2) 67.8( 1 ) ' in (2) and (3) respectively).0x0-bridged complexes are also important in biological systems and an example that may be relevant in this context has been described.' Ba{[(Fe(nta)(H2O)],0)~4H2O (H,nta = N(CH,C0,H)3) comprises from X-ray crystallographic studies octahedral iron centres with tetradentate nta3- ligands (viathe nitrogen and three oxygen atoms) and with the coordination being completed by water molecules and the bridging 0x0 ligand (Fe-0-Fe angle 153.2(6) "). A detailed spectroscopic study of a cobalt peroxo complex has also been reported.I6 A number of interesting spectroscopic and structural problems have been addressed.For example the ESR spectrum of OSOF (in WF, Freon 133a (F,CH,Cl) and SO,) was investigated.I7 Hyperfine coupling to the four axial fluorine atoms but not to the equatorial atom was observed. Multielement NMR studies into isopolytungstate solutions (pH 1.5-8) have shown that [W70,4]6- and [H,W,,04,]'o- are the initial products of acidification. Six metatungstates with Keggin ion type structures were also observed at low pH.'* Although only just within the scope of this review it is worth noting that the controversy over bond-stretch isomerism continues with regard to the MoOCI,(PR,) sy~tems.l'*~~ Although a number of groups believe that this phenom- ena is not yet proven (and may indeed be due to impurities) Gibson and co-workers continue to pursue the topic.The structure of Xe(OTeF,) (4) has been described,' with the xenon atom shown to adopt square planar geometry. Another oxide of xenon (5)was also prepared (equation 2) and characterized by X-ray diffraction studies. l2 M. M. Taqui Khan. K. Venkatasubramanian Z. Shirin. and M. M. Bhadbhade. J. Chem. Soc.. Dalton Trans.. 1992 103. l3 G. R. Willey. J. Palin and N. W. Alcock. J. Chem. Soc.. Dalton Trans. 1992 I 117. D. F. Evans J. Parr S. Raliman. A.M. Z. Slawin D.J. Williams. C.Y. Wong and J. D. Woollins. Polyhedron 1993 11. 337. I5 S. L. Heath A. K. Powell H. L. Utting. and M. Helliwell. J. Chem. Soc. Dalton Trans.. 1992 305. l6 F. Tuczek and E. I. Aolomon. Inorg. Chem.. 1992. 31 944. I' J. H. Holloway E.G. Hope J. B.Raynor and P.T. Townsen J. Chem. Soc. Dalton Trans. 1992 1131. J. J. Hastings and 0.W. Howarth J. Chrm. Soc. Dalton Trans. 1992 209. l9 A. P. Bashall S.W. A. Bligh A. J. Edwards. V.C. Gibson M. McPartlin. and 0.B. Robinson. Angew. Chrm. In[. Ed. Enyl. 1992 31 1607. V. C. Gibson and M. McPartlin. J. Chrm. Soc. Dalton Trans.. 1992. 9. 21 L. Turowsky and K. Seppelt Z. Anory. Allq. Chem. 1992. 609. 153. 0 S Se and Te Interestingly VSEPR rules fail to rationalize the observed distorted tetrahed-ral/pseudo trigonal bipyramidal geometry of (5). The related cations F,Xe(OTeF,)~- and OXeF,(OTeF,)~- have been studied2 in solution by lZ9Xe and 19FNMR the novel 0,XeOTeF cation was observed in SbF solution. Other simple telluriuni-oxygen species which have been studied include [H,0,]Te,CI,-4HZ0 (6) and [H,0,]TeCI,0H~5HZ0 (7) which were obtainedZ3" from reaction of TeCl in conc.and dil. HCI respectively and characterized by X-ray crystallography and Raman spectroscopy (6)has a novel polymeric structure made up of [Te,Cl,]:- chains whilst the anion in (7) is square pyramidal with oxygen in the ' apical site. Cyclic [Te,Mo 2060]- which can be considered to represent the unknown cyclic [TeO(OH),16 was crystallized from aqueous solution.23h Simple sulfur-oxygen compounds still provide significant problems. Thus for example although H2S,0 is very important commercially (in the Claus process i.e. H,S + SO + HZS20Z), and although complexes of S,02 are known the free acid has never been characterized. Ionization of diisopropoxy disulfide (and deuterated analogues) by 70 eV electron impact gives24 H2S,0f + (and deuterated analogues) which as deduced from its collisional activation and neutralization-reionization mass spectrum has a chain HO-S-S-OH that is stable to isomerism for ca.10-s. Although H2S0 (8) (Caro's acid) has been known since 1812 it has not been possible to crystallize it until recently when it was obtained, from H,SO,/H,SO,. The important bond lengths and angles obtained from a crystal structure determinati~n,~ at -130"C are given in Figure 1. The molecules pack into layers linked by almost linear 0-H.. . .O hydrogen bonds. Simple coordination compounds of oxygen-containing ligands/anions have been the subject of numerous studies. For example the reactions of [OSO,(S~O,),]~- with a range of inorganic and organic ligands were investigated;26 the X-ray structure of [NBu~][Os(H,O)(S,O,)(PMe,Ph),] reveals an octahedral geometry about the osmium with the truns S-bonded thiosulfate anions being syn and hydrogen bonded to the axial aqua ligand.26 Phosphorus-oxygen ligands that have been studied include the first structurally characterized example of a complexZ7 containing the phosphinate ligand [Mn{ OPPh,(OPh)),(NCS),]C,H,Me (9) as well as phosphinite complexes obtained28 by selenium elimination from a selenophosphinate (equation 3) PtCI,(PR,) + 4PH,PSeOH -+ [Pt{(Ph,PO),HJ ((Ph2PSeO),H)] + 2HCl + 2SePR (3) Mixed 0,S donor complexes were also studied; a trinuclear example (Figure 2) 22 R.G.Syvret K. M. Mitchell J. C. P. Sanders and G.J. Schrobilgen. Inorg. Chem.. 1992 31. 3381. 23 (a)B. Krebs. S. Bonmann and K. Gretenkord Z. Naturforsch. Teil B 1992. 47. 93; (h)C. Rohl and M. Frost J. Chem. Soc. Chem. Commun. 1992 248. H. Schmidt R. Steudel D. Sulzle and H. Schwarz Inorg. Chem. 1992. 31. 941. 25 W. Frank and B. Bertsch-Frank Angew. Chem.. Int. Ed. Engl. 1992 31 436. *" C. F. Edwards W. P. Griffith and D. J. Williams J. Chem. Soc. Dalton Truns. 1992 145. 27 S. Abbas B. Beagley S.M. Godfrey. D.G. Kelly C.A. McAuliffe and R.G. Pritchard J. Chem. Soc. Dulron Truns.. 1992 1915. 2x M.J. Pilkington A. M.Z. Slawin D. J. Williams and J. D. Woollins J. Chem. Soc,. Ddon Truns. 1992 2425. J. D.Woollins om 1.602(2) 1.464(3) Bond angles (") O( l)-S(1)-0(2) 1O6.8( 1) O(l)-S(l jO(3) 112.9(1) 0(2)-S( 1)-0(3) O( 1)-S(1)-0(4) 121.4(2) I 04.O( 1) 0(2)-S(l)-0(4) 109.3(1) 0(3tS(1)-0(4) 101.0(1) S(l)-0(4)-0(5) 108.7(2) FI(l)-O(l)-S(l) 112(2) II(2)-0W-0(4) 9V3) Figure 1 The X-ray structure25 uf H,SO illustrating the hard and soft characteristics of 0 and S respectively has been isolated29 from the reaction of PtCl,(PMe,) with Zn{ OSP(OPr'),},.The electronic properties associated with the Pt-Pt bonding in Pt"' complexes containing the 'pop' ligand (P,O,H;-) continues to be of intere~t.~' The coordination of phosphorus by oxygen and sulfur has been ~tudied;~' reaction of phenols with the cyclic eight- Figure 2 The X-ray ~trucrure~~ ofthe core of [(Me,P)PtC1(SOP(OPri),)l,Zn~CH,C1 with the Pr' and the Me groups omitted for clarity 29 J.C.Poat. A. M.Z. Slawin D.J. Williams and J. D. Woollins Polyhedron 1992 11 2125. 30 C. M. Che M.C. Cheung Y. Wang and H. B. Gray Inorg. Chim. Actu 1992 191 7. 31 T.K. Prakasha R.O. Day and R. R. Holmes Inorg. Chern.. 1992 31 3391. 0,S Sc. and Te membered [(But),C ,,H,SO ,]POCH 2CF gives [(But ),C H,SO P( 0)OCH ,CF and the pentaoxyphosphorane [(Bu'),C 2H,S0,]P(C 2H,0,)OCH,CF3 which has a pseudooctahedral structure. There has been a large volume of work on metal oxides and as mentioned above no effort to review this area has been made. Nonetheless it is worth noting the preparation of some charge transfer salts of molybdates and tungstates. Tetrathiafulvane (and other organic-metal cations) form3 semiconducting solids with [M6Ol9I2- (M = Mo W) whilst the formation of salts of ,5'-[M0,0,,]~- with N,N,N',N'-tetramethyl-p-phenylenediamine has also been studied., Roesky advanced his work on the formation of M-P-N-P complexes by describing some cyclophosphazene metal oxides.34 Characterization of simple species containing selenium has also been important in 1992.For example HSe- and Se2- were studied by NMR35(x = 3-6) which has enabled the conditions for the formation of these anions in protic and aprotic solvents to be established. Interestingly no Se:- species with x > 6 were observed although the spirocyclic anion [Se(Se5),I2- was studied. The IR and Raman spectra of solid H,Se have been rep~rted.,~ Studies of sulfur-selenium melts by 77Se NMR3 methods showed that the most common eight membered Se- S ring is SeS, with 1,2-Se,S6 being formed in increasing amounts with increasing selenium content of the melt.Sele- nium-sulfur halides were also studied both by NMR38.39 and Raman spectroscopy. SeSX (X = C1 Br) were observed to have chain structures S-Cl and Se-Br bonds being preferred over S-Br and Se-CI and the ,'Se NMR chemical shifts correlate with the electronegativities of the directly bonded neighb~ur.~' The exchange processes in this system were studied by 77Se 2D EXSY meas~rements.,~ A number of selenium iodides were claimed,' to be formed from the reaction of selenium and iodine in CS and 77Se chemical shifts were correlated with structure for bis-chelates with 1,2-' .,dichalcogenates Theoretical investigations that merit discussion include a pseudopotential ab initio study4 of the influence of the phosphine co-ligands in Ni(PR,),(SO,) upon the q'-coordination of SO,.Sulfur-nitrogen chemistry continues to be a subject in need of rationalization and one paper, relates the sulfur-nitrogen enthalpy term to the S-N bond length for a series of S-N compounds; a surprisingly good linear fit was observed. The structures of Te:' and Te,Si+ were also investigated the ore tic all^.^^ The biological significance of Group 16 coordination chemistry has been further investigated. Manganese and iron cubane-like and dimer systems containing cat- echolate ligands i.e. M,(dbcat),(py) (M = Mn Fe); M,(dbcat),(py) (M = Mn '' S.Triki. J. F. Halet 0.Pena J. Padiou. D. Grandjean. C. Garrigou-Lagranpe and P. D. Elhaes J. Chrm. SOL... Dalton Trans. 1992 1217. 33 D. Attanasio M. Bonamico V. Fares. and L. Suber J. Chern. Soc.. Dalton Trans. 1992. 2523. 34 R. Hasselbring H. W. Roesky and M. Noltemeyer. Angrw. Chern..,Int. Ed. Engl.. 1992. 31. 601. " J. Cusick and I. J. Dance. Polyhedron 1991. 10 2629. jh B. A. Paldus. S. A. Schlueter and A. Anderson. J. Roman. Sprctrosc. 1992. 23. 87. 37 T. Chivers. R. S. Latiinen. and K. J. Schmidt. Cun. J. Chern.. 1992 70 719. jH J.B. Milne Can. J. Chem. 1992. 70. 693. " J. Milne and A. J. Williams. Inory. Chrm. 1992. 31. 4534. 40 J. Milne Inorg. Chrm. 1992. 31 4530. 41 B. Olk and R. M. Olk Z. Anorg. Allg. Chew. 1991. 600. 89. 42 J.Reinhold. M. Schuler T. Hoffmann. and E. Wenchuh Inorg. Chew. 1992. 31 559. 4J S. Parsons and J. Passmore Inorq. Chem. 1992. 31 526. 44 P. D. Lyne D. M. P Mingos and T. Ziegler. J. Chm. Sot,.. Dulrnn Truns. 1992 2743. J. D. Woollins n = 6; M = Fe; n = 4,6; dbcat = 3,5-di-tert-butylcatecholate) were prepared and characterized ~rystallographically.~~ Macrocyclic ligands continue to be studied. For example mixed S-N macrocyclic systems were used to complex nickel4' (Figure 3) and copper.47 The conformational behaviour and selectivity of arene thiocrown ether (cyclophane) ligands towards silver was investigated by a combination of crystallogra- phy molecular dynamics calculations and data base interr~gation.,~" Nickel coordination by [15]aneS5 and [16]aneS4 revealed that although the [16]aneS4 gave a simple octahedral complex (with the axial ligands being water molecules) the [15]aneS5 complex is square pyramidal and forms octahedral complexes with MeCN pyridine and Figure 3 The X-ray structure4' of [NiL,]" (L = 8-uza-l,5-dithiac~~clodecane) A series of compounds of formula [Fe,S,(MeCp),][PF,] (y = 0-2) were prepared by reaction of [Fe(MeCp),(CO),] with excess sulfur in refluxing toluene;49 in a subsequent paper49 Fe,S,(MeCp),][PF,] was crystallographically characterized.A general synthetic route to [Fe"'(SR),] -complexes has been reported5' (Equation 4) [Fe(OPh),]-+ 4RSH +[Fe(SR),]-+ 4PhOH (41 The synthesis and X-ray structural analysis of these compounds included a spectro- 45 S.C.Shoner and P. P. Power. lnory. Chem.. 1992. 31 1001. 46 S. Chandrasekhar and A. McAuley Inory. Chem.. 1992 31. 2234. 47 M. M. Bernardo M. J. Heeg R. R. Schroeder L. A. Ochrymowycz and D. B. Rorabacher. lnory. Chem.. 1992. 31 191. 48 (a) J.C. Lockhart. D.P. Mousley. M.N.S. Hill N. P. Tomkinson F. Teixidor. M.P. Almajano L. Escriche J. F. Casabo R. Sillanpaa and R. Kivekas J. Chrm. Soc. Dulton Truns. 1992. 2889; (h)A. J. Blake M. A. Halcrow. and M. Schroder J. Chem. Soc.. Dulron Trans.. 1992. 2803. 49 H. L. Blonk J. Mesrnan J. G. M. van der Linden J. J. Steggerda J. M. M. Smits G. Reurskens. P. T. Beurskens C. Tonon and J. Jordanov. Inorg. Chem. 1992 31. 962 and see 957. 50 L. E. Maelia M. Millar. and S. A. Koch lnory. Chem.. 1992. 31 4594.0 S Se and Te 79 scopic comparison with the [Fe(Cys-S),] -centres which are important in proteins such as rubredoxin.” A range of cubane-like compounds have also been reported; MFe,S (M = Mo W),’l NiFe,Q (Q = S Se),’ and MoS,(CuCl) ’3 cores were all prepared. UVPES data were reported for V,S cluster^.'^ Models for the active site in [FeNiSe] hydrogenases” and [Fe,S2L,I2- for Rieske-type proteins were also scrutini~ed.~~ The first example of stable aldehyde and ketone complexes of zinc have also been rep~rted.’~ Reaction ofZn(EC,H,(CMe,),) (E = S Se) with aryl aldehydes or ketones gives complexes which may be models for transient metal-substrate complexes in metalloenzymes such as liver alcohol dehydrogenase. Group 16 elements continue to be important in coordination chemistry and although many of the compounds will be discussed in other chapters it is relevant to mention some examples here.Iron(II1) chloride has been shown to react with ClOTeF to give Fe(OTeF,) which can be crystallized as a tris-S0,ClF adduct that has octahedral geometry.s8 The use of [B(OTeF,),] -as a weakly coordinating anion has been studieds9 by NMR IR and in the case of the silver(r) salt X-ray crystallography. TeF reacts6’ at -78 “C in CD,Cl with Rh(CO)X(PEt,) (X = C1 Br NCO) to give CRh(C0 )X(PEt )2(TeF3 11CTeF 51. Cluster chemistry has seen some new developments. The reaction of Se(SiMe,) with NiCl,L in THF gives61 clusters such as [Ni,Se,L,] [NisSe,Cl,L,] [Ni,Se,L,] and larger clusters (including [Ni,,Se,,L,“J).Reaction6 ofexcess M(CO) (M = Mo Cr W) with polytelluride solutions gibes a range of products including [M4(CO),8 Te,] - which contains a four-membered M,Te2 ring. Mixed-metal clusters [Fe,M(E),(CO),,] (M = Mo W) containing selenium or tellurium were prepared by reaction of Fe,(CO),(E,) with M(CO),(thf) at room temperat~re.~, The X-ray structure of the tungsten-tellurium compound shows it to have a square pyramidal Fe,Te,W core with the tungsten atom being in the axial site. An inorganic cryptand complex [NaAul,Se,l3- was obtained from AuCN Na,Se and [Et,N]Cl. The selenium atoms are located on the corners of a cube with gold atoms on each edge and the sodium atom at the centre.“ Reaction of the cubane cluster [(WS~,),(S~),(CUPP~,),~~-with Lt,Se gives rise to a new ‘pinwheel’ cluster,6s which can be described as two Cu triangles bridged by tridentate WSei- ligands and capped by two selenium atoms.A cluster containing an unusual geometry of the central sulfur atom Ag ,S(Etdtc) (Etdtc = ethyldithiocarbamate) has been reported; although 51 M. A. Greaney C. L. Coyle R. S. Pilato. and E. I. Steifel Inorg. Chim. Actci 1991 189 11. 52 S. Ciurli. P. K. Ross M. J. Scott S. B. Yu and R. H. Holm. J. Am. Chrm.Snc.. 1992 114 5415. ’’ S. Berneo F. Secheresse and Y. Jeannia Inorq. Chim. ACIN.1992. 191 11. s4 c.E. Davies J.C. Green. N. Kaltsoyannis. M. A. MacDonald J. Qin. T. B. Rauchfuss C. M. Redfern G. H. Stringer and M.G. Woodhouse. Inorg. Chem. 1992. 31 3779. ” N. Baidya. B.C. Noll M.M. Olmstead.;and P. D. Mascharak. Inorg. Chem.. 1992. 31 2999. 5h P. Beardwood and J. F. Gibson J. Chrrii. Soc.. Dulron Trrrns. 1992 2457. ” M. Bochrnann K. J. Webb. M. B. Hursthcwse. and M. Mazid J. Chem. Soc.. Chrm. Commun.. 1992. 1735. 5H T. Drews and K. Seppelt Z. Anorg. Allg. Chem.. 1991 606 201. 59 D. M. Van Seggen. P. K. Hurlbut. M. D. hoirot 0.P. Anderson. and S.H. Straws Inorg. Chrm.. 1992.31. 1423. b” E. A. V. Ebsworth J. H. Holloway and F’. G. Watson. J. Chem. Soc. Chem. Commun. 1992. 1443. 61 D. Fenske H. Krautscheid. and M. Mueller. Angew. Cheni.. Inr. Ed. Engl. 1992. 31. 321. 62 L. C. Roof W. T. Pennington and J. W. Kolis Inorg. Chem.. 1992 31. 2056. h3 P. Mathur D. Chakrabarty M. M.Hossain R. S. Rashid. V. Rugrnini and A. L. Rheingold Inorg.Chew. 1992 31 1106. h4 S. P. Huang and M.G. Kanatzidas Angq~rt-.Chem. Inr. Ed. Engl.. 1992. 31 787. 65 C.C. Christuk. M. A. Ansari. and J.A. Ibers. Angew. Chem. Int. Ed. Engl.. 1992. 31. 1477. 80 J. D. Woollins serendipitously obtained the structure is of interest; the central sulfur atom is coordinated by five sulfur atoms.,‘ A compound containing a twelve membered silver-zinc-sulfur ring was obtained67 according to equation 5. R I RR R /R I/ Me3Si / S \ A SiMe3 AgO,SCFJ c N-Zn 26 Zn-N / \I \4 \ Me,Si 1 ss SiMe II RR R’ ‘R R = 2,4,6-’Pr3C6H3 R The reaction of Ni(S,COEt) with either Li,Se/Se or Li,Te/Te gave a range of Ni,E containing clusters by spontaneous assembly of the oxidized NilV centres.68 The selenium and tellurium cases behave differently giving rise to different chain length bidentate E -exocyclic ligands.The single crystal ESR spectrum of [cO6(S)8(PEt3),] BPh was studied. Although ESR silent at room temperature a low temperature signal is attributed to localization of the unpaired electron on one cobalt; there appears to be a very weak magnetic interaction between the clusters in the solid state.69 The formation of low-dimensional solids is currently of interest. For example partially oxidized compounds such as [TTF],~7[Ni(C3S,)(C3S,)]70 (TTF = tet-rathiafulvalene) and intercalation compounds7 with other organic donors and FeOCl have been described. There have been numerous reports on methods for forming II/VI thin films. Typical is the formation7’ of zinc selenide by the reaction of diethylzinc with diethylselenium in a hydrogen atmosphere at 40G500 -C.New sources of selenium and sulfur utilizing SnSez and SnS for ultra-high vacuum preparation i5iu molecular beam epitaxy are much more convenient than use of the element^.'^ Polychalcogen anions have received substantial attention. The crystal structures of [NPr,],Se and [NEt,],[Se -.;Se;Se,] obtained by reaction of K,Se with selenium have been de~cribed;~ Se 1-is spirocyclic whilst the structure of Se is the first characterization of this ring. The hydrothermal reaction75 of PdCl with K,Se in the presence of KOH gives K,[Pd(SeIo)] which consists of interpenetrating networks of [Pd(Se,),]’-and [Pd(Se,),]’- anions. Se$- and Sei- anions are also coordinated in [Rb( 1 8-crown-6)],[Zn(Se4)(Se,)] which was obtained from the reaction of Zn(OAc) with Li,Se in DMF.76 An interesting main group cluster (Bu‘Ge),S6 not 6h Z.Huang. X. Lei M. Honp. and H. Liu. Inorg. Chem.. 1992. 31. 2990. 67 M. Steiner. H. CrutLmacher. L. Zolnai. and G. Huttner. J. Chem. So(,..Chem. Comrnun.. 1992. 689 ’* J. M. McConnachie. M.A. Ansari. and J. A. Ibers. Inory. Chim. Acru. 1992. 85. ’’)A. Benncini. S. Midollini. and C. Zanchini. ltiory. Chem.. 1992 31. 2132. 7(1 G. Matsubayashi S. Tanaka. and A. Yokoorawa. J. Chem. So(... Dulton Trans.. 1992 1827. ’I J. F. Bringley. J. M. Fabre. and B. A. Averill. Chem. Muter.. 1992. 4. 522. 72 T.L. Chu. S.S. Chu G. Chen J. Britt. C. Ferekides. and C.Q. Wu. J. Appl. Phys.. 1992. 71.3865. 73 T. Shimada. F. S. Ohuchi. and R.A. Parkinson J. Vuc. Sci. Techno/.. A. 1992. 10. 539. 74 J. Dietz U. Mueller. V. Mueller. and K. Dehnicke. Z. Nururfor.xh.. Tcil.B. 1991. 46. 1293. K. W. Kim and M. C. Kanatzidas. J. Am. Chem. Soc.. 1992. 114. 4878. i6 D. Fenske. S. Magull. and K. Dehnicke. Z. Noturforsc~h..7ki/. B. 1991. 46. 101I. 0,S Se and Te 81 having the adamantane structure has been described.77 The molecule consists of two Ge,S rings linked by Ge-S-Ge bridges. Although cluster compounds are under intense study mononuclear systems have also received attention. Solid state metathesis reactions between transition metal halides and alkali metal chalcogenides (tungsten molybdenum) were performed (usually in bombs) by initiating the reactions with heated filaments and once started were self pr~pagating.~~ MOO:-and W03+ react with aqueous S; -in the presence of bpy to give the isostructural mononuclear pentagonal bipyramidal complexes MO(S,),(bpy) with four sulfur atoms and one nitrogen atom in the equatorial plane.79 A binuclear molybdenum complex8' containing edge-on S; - bridging S; - and bridging doubly-end-on H,NNH coordination has been described; here again the molybdenum atoms are in pentagonal bipyramidal environments.Despite the difficulty of the work polychalcogenide cations have been studied by a number of groups. Sulfur reacts with an excess of AsF in liquid SO with a trace of halogen as a catalyst to give S,(AsF,) in quantitative yield.81 [H,Se][SbF,] which decomposes at room temperature has been preparedE2 by treating H,Se with HF and SbF at -78 "C.Crystalline [S,I,][AsF,] was preparedE3 by oxidation ofsulfur with iodine and arsenic pentafluoride (equation 6). $S + 21 + ~AsF,-+ [S,I,][AsF,] + AsF The cation has a distorted triangular prismatic structure with S-S and S-I distances of 1.843(6)and 2.5987(17)A corresponding to bond orders of 2.4 and 1.3 respectively; the distances are even shorter in the SbF salt. A bonding scheme based upon the S unit being bonded to each I; unit in two orthogonal four-electron four-centre 71 systems was proposed.83 A range of [S7X]' cations have been reported in which X = pseud~halogen.~~ The cations were prepared by analogy to the synthesis of [S,I] ;the thermal stabilities of the new cations appear to be a function of the Pearson + hardness of the pseudohalide (increasing hardness leading to decreasing ~tability).~~ The coordination of iodine by the OTeF has been studied.85 Binary (and ternary) compounds containing nitrogen have been the subject of rapid progress in the last year or two.Very unstable new S-N molecules have been observed in an argon matrix. Microwave discharge upon an argon/nitrogen/sulfur vapour gave NS NS, N,S and NSS which were characterized by IR spectroscopy on the normal and isotopically labelled molecules.86 Nitrogen NMR studies on a variety of S-N molecules and anions were reported.87 A method for preparing "N labelled Se,N suitable for mechanistic/NMR studies was described.88 The usefulness of silyl reagents in S/Se/Te-N chemistry has been amply illustrated by 77 W.Ando T. Kadowaki. Y. Kabe and M. Ishii Angew. Chem. Int. Ed. Engl. 1992 31 59. " P. R. Bonneau R. F. Jarvis Jr. and R. B. Kaner Inorg. Chem. 1992 31 2127. 79 P. K. Chakrabarty S. Bhattacharya C. G. Pierpont and R. Bhattacharyya Inorg. Chem. 1992,31,3573. HO Z. Nianyong D. Shaowu W. Xintao and L. Jiaxi Angew. Chem.. Int. Ed. Engl. 1992. 31 87. " M. P. Murchie. J. Passmore G. W. Sutherland. and R. Kapoor J. Chem. Soc.. Dalton Trans. 1992 503. H2 R. Minkwitz A. Kornath. and W. Sawodny Angew. Chem. Int. Ed. Engl. 1992 31 643. 83 M. P. Murchie J. P. Johnson J. Passmore,G. W. Sutherland M. Tajik T. K. Whidden P. S. White and F. Grein Inorg. Chem. 1992 31 273. 84 R. Minkwitz and J.Nowicki Z. Anorg. Allg. Chem. 1992 607 96. H5 L. Turowsky and K. Seppelt Z. Anorg. Allg. Chem. 1991. 602 79. 86 P. Hassanzadeh and L. Andrews J. Am. Chem. Soc. 1992 114 83. '' T. Chivers and K. J. Schmidt Can. J. Chem.. 1992 70. 710. '* V. C. Ginn P. F. Kelly and J. D. Woollins J. Chem. Sac. Dalton Trans. 1992 2129. J. D. Woollins several pieces of elegant work. The formation of poly(aryl/alkyloxothiazenes) by condensation of sulfonimidates has been described89 (equation 7). Me,SiN-S(0)ROR +[NSOR] (7) E[NCMe,(SiMe,)] (E = Se Te) have been prepared and characterized by X-ray crystallography and 77Se/'25Te NMR.90 Se(NSO) reacts with TeCI to give" the five-membered mixed-chalcogen ring system (Cl,Te)NSNSe and with XS0,H to form + . [Se,N,S]' The first tellurium(I1) radical-cation-containing compound [Te(N(SiMe,),),]'+ [AsF,] - formed by warming a mixture of Te[N(SiMe,),] and AgAsF from -78 "C to room temperature has been described;' The Te-N distance in the cation was reduced relative to the parent neutral molecule.The reaction of TeCl with (Me,SiN),S gives9 the novel tellurium-sulfur-nitride shown in Figure 4. Figure 4 The X-ray structure93 ofTe,S,F,N A number of cationic S/Se-N species have been reported. Reaction of tris(trimethylsily1)aminewith selenium tetrachloride gives Se,NCI which undergoes chloride abstraction when treated with gallium trichloride to give9 [ClSeNSeCl] [GaCl,] (Equation 8). Closely related to this it was noted that the reactiong5 of [SeCl,][AsF,] with N(SiMe,) gives [(Cl2Se)N(SeC1,)][AsF6].Dehnicke described XY A.K. Roy J. Am. Chem. Soc.. 1992 114 1530. 90 M. Bjoervinsson H. W. Roesky F. Pauer D. Stalke and G. M. Sheldrick Eur.J. SolidSrure Inory. Chem. 1992 29 759. 91 A. Haas J. Kasprowski. and M. Pryka. Chem. Ber. 1992. 125 789. 92 M. Bjoervinsson T. Heinze H. W. Roesky F. Pauer D. Stalke and G. M. Sheldrick Angew. Chem. Int. Ed. Engl. 1991 30 1677. 93 J. Munzenberg H. W. Roesky S. Besser R. Herbst-lrmer and G. M. Sheldrick Inory. Chem.. 1992 31 2986. 94 R. Wollert. A. Hollwarth G. Frenking D. Fenske H. Goesmann and K. Dehnicke. Angew. Chrm. In?.Ed. Engl. 1992 31 1251. 95 M. Broschag T. M. Klapotke 1. C. Tornieporth-Oetting. and P. S. White J. Chrm. Sor...Chem. Commun. 1992.1390. 0 S Sc. and Tc. the synthesis96 of [Se,N,CI][GaCl,] according to equation 9. The cation was characterized by both X-ray crystallography and vibrational spectroscopy. [C1SeNSeC1][GaC14] SbPh3 -t [Se,N,CI][GaCI,] (91 Following an earlier report by Dehnicke that the reaction of Me,SiN with SeCl gives Se,N, Chivers re-investigated the reaction9' and suggested that the original formulation is incorrect and that the product should be re-formulated as Se,N,CI,. This issue awaits final resolution. The preparation and structure of the mixed chalcogen [Se,N,S][AsF,] has also been reported.98 The preparation of a number oi' five-membered organo-S/Se-N radical cations which have potential in the study of organic metals has been studied. Hence an interesting solid-state rearrangement of 1,3,2,4-dithiadiazoles to their 1,2,3,5 ana- logues has been reported.99 The preparation"' of 5-(trifluoromethy1)-l ,2,3,4-trithiazolium hexafluoroarsenate ([CF,CNSSS][AsF,]) from the reaction of CF,CN with Ss+/Sz+ has been described.Preparation and structural details for (cy-anopheny1)dithia- and diselenadiazolyl radicals and related six-membered rings have lso been The preparation of P N-S and P-N-Se rings from R,PN,(SiMe,) has been described"3~"4 (equation 10). R I N.E.N NSiMe3 N.Se ii Ph PPh2 +-!-/ 'p\N. A.N/ Ph2qN(SiMe3)2 __f Ph2P Kse" N\ /pPh2 (10) I (i) E = S SCl, or SOCI E =SC +SeCh +t s%c12 R (ii) RSeC1 R = Me Et Ph Binary Group 15/16 compounds also merit some mention. Photochemical redis- tribution reactions of mi~tures''~ of sr-P,S31 and sr-P,Se,I in CS gave P,S,SeI and 'Ih R.Wollert. B. Neumuller. and K. Dehnicke Z. Anorg. A//q. Chem.. 1992 61 191. '-J. Siivari. T. Chivers. and R. Laitinen. Anyrn.. Chrm.. Int. Ed. EnqI. 1992 31. 1518. un E.G. Awere J. Passmore and P.S. White. J. Chem. Soc.. Dulton 7run.s.. 1992 1267. VQ C. Aherne A. J. Banister. A. W. Luke. J. M. Rawson and R. J. Whitehead. J. Cliem. So(... Dulfon 7tuns.. 1992 1277. '"O T. S. Cameron R.C. Haddon. S. M. Mattar. S. Parsons. J. Passmore. and A. P. Ramirez. /nor(/. Chcrn.. 1992 31. 2274. 101 A. W. Cordes. R.C. Haddon. R. G. Hicks. R.T. 0akley.and T.T. M. Palstra. Inorq. Chmi..1992.31. 1802. I('' K. Bestari. G. Ferguson. J. F. Gallagher. and R.T. Oakley.Inorq. Chem.. 1992 31. 442. T. Chivers S.S. Kumaravel. M. Parvez. and M.N. S. Rao. Inory. Cheni.. 1992 31 1274. I04 T. Chivers. M. Edwards. and M. Parvez. Inory. Chem.. 1992 31. 1861. l(14 R. Rlachnik. P. Loennecke. and B. W. T.Attershall. J. Chrm. Soc... Dulron Trum.. 1992. 3105. 84 J. D.Woollins P,S,SeI, which were studied by NMR. A number of As-S/Se systems have been st~died.'~~-'~~ [As,,Se,12-(n = 2,4)was obtained by treatment of As,Se with Se2- in DMF.'" The structure and bonding in a thio-arsenium system was discussed with particular interest in the degree of p-7c-bonding.'08 The reactions of As-Se anions with M(CO) (M = W Mo) have been investigated."' Phosphorus-selenium systems also form metal complexes. Thus reaction of P,Se with polyselenides gives P,Sei- which reacts' lo with Fe(CO) to give [Fe,(CO),- (PSe,),12 -.K[Ph,P(Se)NP(Se)Ph,] has been shown to react' "with ReOCl,(PPh,) with displacement of triphenyl phosphine and two chloride ions to give Re- OCl[Ph,P(Se)NP(Se)Ph,] which rapidly loses one selenium atom from each bidentate ligand to give ReOCl[Ph,PNP(Se)Ph,],. The formation of binuclear metal complexes by reactions' l2 between suitable silyl reagents with an M-Ph,PCl complex once again shows the utility of these reagents (equation 11). 2[(CO),Cr(Ph,PCI)J + (Me,Si),Se -+ [(CO),Cr(Ph,P)J,Se + 2Me3SiC1 (1 1) Finally M-S/Se-N and related areas continue to be fruitful. A detailed study of a technetium thionitrosyl system investigated the effect of the other ligand upon the N S coordination in this difficult system;'13 no reasons for the use of technetium were presented.The reaction of S,N with [M,X,I2- anions (M = Pd Pt; X = C1 Br I) has been studied. With palladium,' l4 binuclear Pd" compounds containing S,N or S,Ni -are obtained whereas with platinum Pt'" complexes containing thefac-S,Ni- ligand are formed."' The first reaction of S,N, to give [PdCl,(S,N,)]- has been described.' l6 The reaction of [WCl,(NSeCl)] with PPh,Cl has been shown to give [PPh,],[WCl,(NSeCI,)] which contains the NSeCli- ligand.' l7 The coordination chemistry of some of the eight-membered substituted thiazenes formed in equation 10 has been shown to be particularly including N-bonding q2-E,E' and p2-q3-N,S,S'coordination. Acknowledgements.I am grateful to A. M. Z. Slawin for preparing the crystal structure diagrams. B. Siewert and U. Mueller Z.Anorg. Allg. Chem.. 1992 609 77. lo7 M. A. Ansari J. A. Ibers S.C. O'Neal W.T. Pennington and J. W. Kolis Polyhedron 1992 11 1877. lo' N. Burford T. M. Parks B. W. Royan J. F. Richardson and P. S. White Can. J. Chem. 1992 70 703. Io9 S.C. O'Neal W.T. Pennington and J. W. Kolis Znorg. Chem. 1992 31 888. J. Zhao W.T. Pennington and J. W. Kolis Angew. Chem. Znt. Ed. Engl. 1992 31 265. ''I R. Rossi A. Marchi L. Marvelli M. Peruzzini U. Castellato. and R. Graziani. J. Chem. Soc. Dalton Trans. 1992 435. 'I2 K. Merzweiler and H. J. Kersten Z. Naturforsch. Teil B. 1991 46 1025. 'I3 J. Lu and M. J. Clarke J. Chem. Soc.. Dalton Trans. 1992 1243. V. C. Ginn P.F. Kelly A. M. Z. Slawin D. J. Williams and J. D. Woollins. J. Chem. Soc. Dalton Trans. 1992 963. P. S. Belton V.C. Ginn P. F. Kelly and J. D. Woollins J. Chem. Soc. Dalton Trans. 1992 1135. 1I6 P. F. Kelly A. M. Z. Slawin 13.J. Williams. and J. D. Woollins Angew. Chem.,In?.Ed. Engl. 1992,31,616. S. Volger and K. Dehnicke Z. Naturforsch. Teil B 1992. 47 301. 118 T. Chivers M. Edwards A. Meetsrna J. C. van de Grampel and A. van der Lee Inorg. Chem.. 1992.31 2156. T. Chivers R. W. Hilts I.H. Krouse A. W. Cordes R. Hallford and S.R. Scott Can. J. Chrm. 1992,70 2602. T. Chivers and R. W. Hillts Znorg. Chem. 1992. 31,5272.

ISSN:0260-1818    

DOI:10.1039/IC9928900073

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

7 The Halogens and Noble Gases By D.A. ARMITAGE Department of Chemistry King's College London Strand London WC2R ZLS UK 1 Introduction This chapter covers the 1992 literature and roughly follows last year's format. 2 Fluorine The syntheses of ClF, KrF, Xe, and XeF are reported in Inorganic Syntheses.' Calculations support short N . * . halogen interaction distances in the ammonia complexes with F, Cl, and CIF with that for ClF being the shortest (230pm). The increased demand for electrophilic fluorinating agents has led to the synthesis of a series of N-fluoro quaternary salts of quinuclidine 1,4-diazabicyclo[2.2.2)octane and the latter's monoquaternary salt. The fluoroammonium salts are stable high melting solids which readily fluorinate the enol diacetates of testosterone and androsterone 1-morpholinocyclohex-1 -ene acetanilide PhC(Na)(Et), and PhMgBr in very good yield.3 Monofluorination of RLi and RMgX (R = Bun Bus Ph) can be readily achieved at -60 "C in di-n-butyl ether using F, giving RF.Ru'MgCl is ~nreactive.~ A quantitative scale for oxidative fluorination based on the relative F+ detachment energies has been obtained from local density functional calculations based on KrFt as zero.' The data for 36 XF' agents closely supports qualitative data and considers the number of fluorine atoms oxidation state and electronegativity of the central atom together with the number of lone pairs and the geometry of the central atom. Calculations reveal a number of unexpected results and suggest a decrease in the oxidative strength with a decrease in the number of lone pairs making XeF a better oxidizing agent than XeF perhaps surprisingly.BuiP'HF and Bu",+H,F; are both useful reagents in the nucleophilic fluorina- tion of chloro and bromo substituted nitrobenzenes while BLI",+H,F with NBS fluorinates methyldithiocarbamates Ar(PhCH,)NC(S)SMe in very good yields to give the trifluoromethylamines Ar( PhCH,)NCF3.6 Just as crown ethers act as alkali metal cation traps so do coordinated fluorides. Reacting [Cp*TiF3] with NaF in MeCN in 'Inorganic Syntheses'. ed. R. N. Grimes Wiley-Interscience New York 1992 Vol. 29. 1. Roeggen and T. Dahl J. Am. Chem. Soc.. 1992. 114 511. R. E. Banks S. N. Mohialdin-Khaffaf G. S. IA I. Sharif and R. G. Syvret J. Chem. Soc.. Chem.Commun. 1992 595. J. DeYoung H. Kawa and R. J. Lagow J. Chem. Soc.. Chem. Comrnun.. 1992. 81 1. K.O. Christe and D.A. Dixon J. Am. Chein. Soc.. 1992 114 2978. ' Y. Uchibori. M. Umeno H. Seto. Z. Qian and H. Yoshioka Synletr 1992 345; M. Kuroboshi and T. Hiyama Tetrahedron Left.. 1992. 33. 4177. 85 D. A. Armitaye the presence of Ph,P+CI- gives the complex (Ph,P)+[(Cp*,Ti,F,),Na+] -in which Na' is sandwiched between two layers of fluorine atoms in an eight coordinate environment with Na .*. F contacts from 238-253 pm.' 3 Polyhalogen Cations and Anions The Raman spectra of CliSbF; supports a bent C,, structure for the cation while analysis of the structure of Brl supports a skew configuration of the terminal bromine atoms on an almost linear Br central unit.This is some 5-6 kJ mol- 'more stable than the planar trans C,,form found in crystals of Brl MF (M =As,Sb).* The structure of S,I,(MF,) shows the S21i+cation to have an open-book structure with an S unit as the spine and two I units lying parallel to this. The S-S and 1-1 bond lengths are about 180 and 260 pm respectively and support multiple bonding within these units. The diatomic units are held together through four-centre interactions of their n* orbitals. The S-I bonds are about 300 pm indicating a bond order of only 0.1 comparable in length to those in charge transfer complexe~.~ 1,3-Diiodobicyclo[ 1.1.llpentane reacts with pyridine to give the ionic derivative [C5H5NC5H,13C,H4NC5H,]+I; (1 ) with linear cations and anions and the shortest 'non-bonded' C-C interactions (180pm) recorded to date for any organic com- pound." A resonance structure involving such a bond is invoked.The 1 ion (2) isolated as its Ph4P+ salt is polymeric with interconnected 1 units of appropriate C, symmetry with 1-1 distances in the two ranges of 305-329 pm and 273-281 pm and the I anion unit interacting with two I units at both ends." 4 Fluorosulfonium Derivatives XeF+(MF;) (M =As,Sb) will fluorinate (C,F,),S in HF to give deep violet crystals of (C,F,),SF+SbF; which slowly decompose after 24 h at room temperature. A structure determination shows the S-F bond to be short.' Perfluoro sulfur(1v) compounds also result from XeF'MF; with fluorination by F+ occurring for (CF,),SF,- to give (CF,),SF:-,.(CF,)FS=O behaves similarly to give (CF,)- S(O)FT whereas (CF,),SO forms13 the Xe complex (CF,),SOXeF+. 'H. W. Roesky M. Sotoodeh and M. Noltemeyer Angew. Chem. Inr. Ed. Engl.. 1992 31. 864. R. Minkwitz. J. Nowicki H. Hartner. and W. Sawodny Specrrochimicu Acta .4 1991 47. 1673 K.O. Christe D.A. Dixon and R. Minkwitz. Z. Anory. Ally. Chem. 1992 612 51. M. P. Murchie J. P. Johnson. J. Passmore G. W. Sutherland M. Tajik T. K.Whidden P. S. White and F. Grein Inorg. Chem. 1992. 31 273. J.L. Adcock A.A. Gakh J. L. Pollitte and C. Woods J. Am. Chem. Soc,.. 1992 114 3980. " R. Poli J.C. Gordon. R. K. Khanna and P.E. Fanwick Inorg. Chem. 1992 31. 3165. R. Minkwitz G. Nowicki and H. Preut. Z. Anory. Allg. Chem.. 1992 611. 23. l3 R. Minkwitz and W. Molsbeck Z.Anory. AIIg. Chem. 1992. 612 35. The Halogens atid Noble Gases 87 5 Rare Gas Compounds The high sensitivity of the chemical shift of 129Xe NMR to the local electronic environment has been used to show that if Xe is co-adsorbed with CCl in NaY zeolite at 144K then the CCI absorbed with xenon in the formed supercage suppresses the gas-liquid transition of Xe. Also the gas-liquid transition of Xe in super cages without CCl influences distribution of CC1 in the ze01ite.I~ Interest in the isolation of alkynyl iodonium salts (section 7) has led to the synthesis of analogous isoelectronic Xe(I1) derivatives that have been characterized at low temperature by reacting Bu'C=CI,i or RCGCSiMe with XeF,/BF to give the tetrafluoroborate salts (equation 1).They react with Ph,P to give phosphonium salts and release of Xe.' R-CZEC-SiMe + BF;OEt + XeF + R-CECXe'BF; + Me,SiF (1 1 XeF will cleave the B-0 bonds of B(OR) to give FXeOR (R = SO,CF and SO,C,F,) and Xe(OR) (R = COCF and COC,F,) while 1-chloro-2-fluorocyclo-hexanes result" from cyclohexene with alkyl hypochlorites and XeF,. Krypton difluoride fluorinates OsO to give cis-OsF,O, and not OsF,O as previously reported." The mean amplitude of vibrations of planar XeF; confirms that lone pairs exert repulsion thus forcing bond lengthening.' 6 Organofluorine Compounds Interest in the use of tertiary perfluoroalkyl amines as blood substitutes has led to structural studies; the electronegative perfluoroalkyl group results in an increase in C-C and C-N bond lengths and a widening of the angles at nitrogen.Fluorination of Me,N widens the CNC angle from 110.9 to 117.9' and in (C,F,),N to 119.3 ". Despite an increase in the C-N bond length from 142.6 to 148.2 pm contacts between non-geminal fluorine atoms are up to 36 pm less than the van der Waal's interaction distance. While complexes containing the I~-C,X ligand (X = C1,BrJ) have been known for some time the pentafluorocyclopentadienyl complex has only recently been de- scribed.20 Reacting [Cp*Ru(MeCN),] +CI with C,F,OTI gives the q5-oxopenta- Auorocyclohexadienyl complex which decarbonylates on flash vacuum pyrolysis at 750 "C to give the pentafluorocyclopentadienyl derivative in 20% yield. The I9FNMR absorption is only four ppm upfield from C,F; while the mass spectrum shows a prominent peak for RuC,Fl.The vibrational spectra of the trihalocyclopropenium ions C,Xi (X = Cl,Br,I) show symmetric C-X stretching vibrations2' at 458,269 and 180 cm- and ring breathing modes at 1790 1732 and 1650 cm ~ Elimination of Me,C from [(BU; P),CH,]PtH(CH,Bu') at room temperature gives l4 T.T. P. Cheung J. Phys. Cheni. 1992 96 5505. If V. V. Zhdankin P. J. Stang and N. S. Zefirov. J. Chem. Soc.. Chem. Commun.. 1992 578. 16 B. Cremer-Lober H. Butler D. Naumann and W. Tyrra Z. Anorg. Allg. Chem.. 1992 607 34; D.F. Shellhamer M. J. Horney A. L. Toth. and V. L. Heasley Tetrahedron Lert.. 1992. 33 6903. '' K.O. Christe and R. Bougon J. Chem. Soc. Chem. Commun. 1992 1056. '* E. J. Baran J. Mol. Struct.1992 271 327. 19 M. Gaensslen U. Gross H. Oberhammer and S. Rudiger Angew. Chem.. Int. Ed. EnqI. 1992 31 1467. 0. J. Curnow and R. P. Hughes. J. Am. Chem. Soc. 1992. 114 5895. M. J. Taylor P. N. Gates and P. M. Smith. Spectrochini. Acta A 1992. 48. 205. 88 D. A. Arrnituge the 14-electron Pto fragment that readily” inserts into the C-E’ bond of C6F6 while successive photolytic displacement of C2H4 from qS-R,C51r(C,H,) (R = Me,H) by C6F6 gives both q2-and q4-C6F complexes,23 with the fluorine atoms of the q2-complex bent away from the metal. The pentafluorophenyl group will stabilize the acetylide bridged complexes dppePt(pC-CPh),Pt(C,F,) and (Ph3PMe+)2(C6F,),Pt(p-C=CPh)2Pt(C,F,);- and the neutral gold cluster (C6Fs)4Au,o(PPh,)6.24 (Trifluoroethy1idyne)sulfurtrifluoride F,CC-SF occurs as two solid phases with CCS angles of 171.4 “ and 162.9 @.The small bending force constant is explained in terms of a low-lying excited carbene state. Rapid dimerization to the truns-alkene occurs and further carbene insertion into one C -S bond occurs more slowly to give the trimer (3) (equation 2).,’ (31 Odourless trifluoromethyl alkyl tellurides CF,TeR (R = Bu’ or CH,Ph) result from (CF,),Te and R,Te and provide for vapour phase deposition of tellurium alloys.26 (CF,),Te is formed from (CF,),TeCl and (CF,),Cd. It adds fluoride and is thought to be oxidized by XeF to (CF,),TeF,. The oligomers (R,),Te (R = C2F5 C3F7 and C,F,) are more stable and result,’ from TeCl and (R,),Cd. 7 Iodoniurn Derivatives The synthesis and use of alkynyl(pheny1)iodonium salts in organic synthesis has been reviewed.28 The diyne triflates PhIC-C(p-C6H4),C~CIPh.20Tf and PhIC-C(CH2),C=C1Ph.2OTf result from the stannyl diyne and PhICN+OTf- and react with Ph,P to give the bisphosphonium salts.29 Phenyl(2,2-dimethyl-4-(diethyl-phosphono)-2,5-dihydro-3-furyl)iodonium salts result from the allene (4) and PhIO/BF (equation 3).The perchlorate crystallizes as a dimer3* with a P=O -+ I interaction of 283.4pm and an angle at I of 99.2”. c=c=c/ PhIOF3B.OEt2 <OMe \ NaX (31 (Et0)2P+ ..IPh X-0’ (4) ” P. Hofmann and G. Unfried Chem. Ber.. 1992. 125 659. 23 T.W. Bell M. Helliwell M.G. Partridge and R.N. Perutz Oryanometallics 1992 11. 1911. 24 A. Laguna M.Laguna M. C. Gimeno and P. G. Jones Organometallics 1992. 11.2759; J. Fornies. M. A. Gomez-Saso E. Lalinde F. Martinez and M.T. Moreno. ihid. 1992 11. 2873. 25 J. Buschmann R. Damerius R. Gerhardt D. Lentz. P. Luger. R. Marschall. D. Preugschat K. Seppelt. and A. Simon J. Am. Chem. Soc. 1992 114 9465. 2h D. C. Gordon R. U. Kirss and D. W. Brown Organometallics. 1992 11 2947. ” D. Naumann. H. Butler J. Fischer J. Hanke J. Mogias and B. Wilkes,Z. Anory. Ally. Chem.. 1992,608.69. ’’ P.J. Stang Anyew. Chem. Int. Ed. Engl. 1992 31 274. 29 P. J. Stang R. Tykwinski. and V.V. Zhdankin J. Ory. Chem. 1992 57. 1861. 30 N.S. Zefirov A. S. Koz’min T. Kazumov. K. A. Potekhin V. D. Sorokin V. K. Brel E.V. Abramkin Yu.T. Struchkov V. V. Zhdankin and P. J. Stang J.Org. Chrm. 1992. 57. 2433. The Halogens and Noble Gases Bicycloalkenyldiiodonium salts result from cyclopentadiene and PhICKCIPh' + and react with nucleophiles to give a range of substitution products (Equation 4) while with Ph,P the diiodide result^.^' +IPh x PhIO and triflic acid react with arenes to give mixed diaryliodonium triflates of use in organic synthesis., The salts Ar,I+I-and Ar,I+Cl- (Ar = 4-halophenyl) react with PhTeNa or Na,Te to give the appropriate diary1 telluride.33 Electronic factors determine the regioselectivity of radical reactions of Ar21 and aryl(rn-carboranyl- + 9-y1)iodonium cations and proceed via [C,B ,H -I-Ar]. radical intermediates. However steric factors provide the major influence in the polar reactions and readily explain the ~rtho-effect.~~ Although difluoroiodo compounds have been used as synthetic intermediates none has been isolated to date.However treating 4-iodotricyclene with excess XeF in CCl gives the difluoroiodo derivative RIF (equation 5) as a pale yellow waxy solid that is stable in air for a few hours and indefinitely in solution under an inert atmosphere. No spectroscopic evidence was found to support the presence of any tetrafl~oride.,~ The first known binary nitrogen-iodine cation 12N3+(isolated as its SbF salt) results from iodoazide and iodine in SbF, or from fresh silver azide and I SbF,. This azidoiodoiodine cation is explosive even below -20 "C and the Raman spectrum supports an 1-1 bond slightly weaker than that in I, and an N-I bond slightly stronger than in IN,.The suggested structure involves a non-linear chain with approximate tetrahedral angles at the N-I bond. Slow decomp~sition~~ gives I;+(SbF;) and N,. 8 Oxygen Derivatives Dehydrating HIO or H510 with first conc. H,PO at above 300 "C,then with conc. H,SO at room temperature gives (IO,),HSO, which contains37 iodine in mixed oxidation states in the cation (5) two-thirds is iodine (111) as square planar 10 units and one-third is trigonal pyramidal iodine (v). A range of transition metal periodates 31 P.J. Stang. A. Schwarz T. Blume and V.V. Zhdankin. Tetrahedron Lett. 1992 33 6759. " T. Kitamura J.4. Matsuyuki K. Nagata. R. Furuki and H. Taniguchi. Synrhesis. 1992. 945. 33 J. You and Z. Chen Synthesis 1992 633; Synth.Commun. 1992 22 1441. 34 V. V. Grushin I. I. Demkina and T. P. Tolstaya J. Chem. Soc. Perkin Trans. 2 1992 505. 35 G. W. Bradley J. H. Holloway H. J. Koh. D.G. Morris. and P.G. Watson J. Chem. Soc. Perkin Trans. I 1992 3001. 36 I. C. Tornieporth-Oetting P. Buzek P. von Rague Schleyer and T. M. Klapotke Angew. Chem.. Int. Ed. Engl. 1992 31 1338. '' A. Rehr and M. Jansen. Z. Anorg. AIIg. Chem. 1992 608. 159. D.A. Armitage have proved useful oxidants for alcohols aldehydes and benzyl halides including the gold derivative Na,KAu[IO,(OH)],~KOH~l 5H20 which shows square planar Au with two IO,(OH),-ligands bidentate.38 (5) 0= Iodine 0=Oxygen (Reproduced by permission from Z. Anory. Ally. Chern. 1992 608 159) PhI(OTf) and PhI(OCOCF,) will couple alkyllithium reagents RLi to give R-R (R = Bun BuSec Bu').PhI(OTf) undergoes electrophilic addition to alkynes to give (E)-~-[trifluoromethanesulfonyloxy)vinyl]iodonium triflates in good yield.39 Imperfect mixing on bistability in the BrOS -Celt'-Br -continuous-flow stirred tank reactor results in a broadening of the bistable region particularly at higher flow rates. This is thought to be due to effective initial segregation of the entering bromide from the bulk of the reacting mixture in packets dispersed uniformly throughout the reactor.40 The 1 1 and 7 :5 reactions of bromate with thiocyanate are indicated (equations 6 and 7). BrO + SCN-+ H,O -* HSO + HCN + Br-(61 7Br0 + SSCN-+ 2H+ +SBrCN + Br + 5SO:-+ H,O (7) The reaction of bromate with thiocyanate gives HSO, HCN and Br- with thiocyanate in excess but Br' Br, and SO:-with bromate in excess.41 The reaction occurs in three stages with the first involving consumption of thiocyanate the second consumption of cyanide and the third bromine accumulation.The kinetics of the reaction of iodine and triiodide with thiosulfate suggests the intermediacy of the I,S,Oi- adduct which though thermodynamically stable is kinetically reactive and dissociates to give IS,O;. The structures suggested involve I-S and not 1-0 bonding., 3R A. C. Dengel A.M. El-Hendawy. W. P. Griffith. S. I. Mostafa and D. J. Williams J. Chem. Soc. Dalton Truns.. 1992 3489. D. H. R. Barton J. Cs. Jaszberenyi K. Lessmann and T. Timar Terrahedron. 1992.48,8881:T.Kitamura R. Furuki H. Taniguchi and P. J. Stang ibid. 1992 48 7149. 4" L. Gyorgyi and R. J. Field J. Fhys. Chem. 1992 96 1220. 4' Y.-X. Zhang and R. J. Field J. Phps. Chem. 1992 96 1224. 42 W. M. Scheper and D. W. Margerum. Inorq. Chem. 1992 31. 5466. The Halogens and Noble Gases 9 Halide Traps Condensing HgBr with sodium cyclohexanethiolate followed by recrystallization from pyridine gives the complex Hg,(SC6Hl l)12Br in which six Hg atoms surround one bromide in a distorted ~ctahedron.~~ The carbollide mercury halide trap (HgC2B,oHlo)4 shows fluxional behaviour in solution but adds two iodide ions stepwise with consequent 199Hg NMR resonance ~harpening.~~ The structure of the Ph4As+ derivative shows the four mercury atoms in a plane with the two iodine atoms one above and one below both equidistant from one pair of Hg atoms (330.4and 330.6pm) but not the other pair (327.7and 389 10 Weak Interactions The crystal structure of cyanuric chloride (NCCl) shows .n-stacked layers with in-plane intermolecular interactions being short and approximately linear with six close contacts for each ring at 310.0and 31 1.3 pm.N . . . C1 contacts are not observed so extensively in other rings (for example 2,4,6-trichlor0-1,3,5-tricyanobenzene).~~ The structure of the aniline/dicyclohexylgallium bromide complex shows intramolecular hydrogen bonding with bromine (H . . . Br 248pm). This hydrogen bonding distorts the tetrahedral coordination at gallium and provides the first example of such in main group corn pound^.^^ 43 T.Alsina W. Clegg K.A. Fraser and J. Sola J. Chem. Soc.. Cheni. Comniun. 1992 1010. 44 X. Yang S. E. Johnson S. I. Khan. and M. F. Hawthorne Angew. Chem. Int. Ed. Engl.. 1992 31. 893. 4s X. Yang C. B. Knobler and M. F. Hawthorne J. Am. Cheni. Soc.. 1992. 114. 380.

ISSN:0260-1818    

DOI:10.1039/IC9928900085

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

8 Inorganic and Organometallic Polymers By I. MANNERS Department of Chemistry University of Toronto 80 St George St. Toronto M5S IAl Ontario Canada 1 Introduction Polymers containing inorganic elements continue to attract considerable attention because of their fundamentally interesting and unusual properties and their applica- tions as speciality materials.’-7 This review concentrates on developments in inorganic and organometallic polymer chemistry during the year 1992 and has the same format as the previous article’ in the series which covered the year 1991. The first part of the review sequentially covers the well-established4 inorganic polymer systems (poly- siloxanes polyphosphazenes and polysilanes); a brief introduction to each of these classes of inorganic polymer systems was included in the appropriate sections of the previous article of this ~eries.~ The second part consists of separate sections that consider other polymers based on main-group elements and transition metals.As with the previous article emphasis is placed on polymers with inorganic elements within the main chain rather than in the side-group structure. 2 Polysiloxanes (Silicones) Polysiloxanes currently the most commercially significant class of inorganic polymers continue to attract enormous interest. An important area of current research involves the incorporation of siloxane segments into copolymer structures with the aim of preparing new polymeric materials with novel combinations of properties. For example Lenz and co-workers have described studies of the relationship between polymer structure and glass transition temperature for alternating silylarylene-siloxane copolymers ( 1).8 These polymers are of considerable interest as materials with a wide range of operating temperatures.The relationships studied include how the Tgvalues vary with increased siloxane group ‘Silicon-Based Polymer Science’ ed. by J. M. Zeigler and F. W. G. Fearon. Advances in Chemistry 224 American Chemical Society Washington D.C. 1990. ‘Inorganic and Organometallic Oligomers and Polymers’ ed. by R. M. Laine and J. F. Harrod Kluwer Publishers Amsterdam 1991. ’ ‘Siloxane Polymers’. ed. J. A. Semlyen and S. J. Clarson. Prentice Hall Englewood Cliffs N.J. USA 1991. J. E. Mark H. R. Allcock and R.West ‘Inorganic Polymers’ Prentice Hall Englewood Cliffs N.J. USA. 1992. ’ Journul of Inorganic und Organometallic Polymers. Plenum New York from 1991. ’ I. Manners Polymer New. 1993 18 133. ’ I. Manners Ann. Rep. Proy. Chem.. Sect. A Inorg. Chem. 1991 88. 77. P. R. Dvornic and R. W. Lenz Mucromoltwles 1992 25 3769. 93 94 I. Manners content in the polymer main chain; how chain stiffening is influenced by the presence of different aromatic main-chain groups; and how the glass transitions are influenced by bulky and unsaturated side-group substituents. A particularly exciting development reported by Frechet and co-workers involves the use of the intermolecular hydrogen-bonding strategy to induce side-chain liquid crystallinity in polysiloxanes and the subsequent application of this methodology to prepare polymers that are ferroele~tric.~~' The synthesis of ferroelectric polymers was achieved by using polysiloxanes with pendant p-alkoxybenzoic acid groups complexed with an optically active (S)-(-)-rrans-4-(2-methoxypropyloxy)-4'-stilbazole as a chiral acceptor.The polymeric complexes (2)form tilted chiral smectic C* (SC*)phases over an extended temperature range as a result of the linear structures with a large length-to-breadth ratio. The spontaneous polarization P, measured by the Saw- yer-Tower method from hysteresis loops was found to decrease with increasing temperature for most of the complexes studied. This behaviour which is normal for chiral smectics occurs as a result of the decrease in dipolar ordering and arises because of the increased rotations about the molecular axis at higher temperatures.hydrogen bond H-bonded rnesogen I chiral acceptor Zentel and co-workers have also recently prepared a ferroelectric liquid crystalline polysiloxane. In this case the polymer possessed both a smectic C* and an A* phase and fast electroclinic switching was detected in the latter.' Chojnowski and Rozga have reported an interesting synthesis of polysiloxanes (3) with electron-donating organophosphorus pendant groups. * The polymers were prepared oiu the anionic ring-opening polymerization of cyclic siloxanes with pendant organophosphine organophosphine oxide or organophosphine sulfide groups in U. Kumar T. Kato. and J. M.J. Frechet J. Am. Chem. Soc,.. 1992. 114 6630. I" U. Kumar J. M. J. Frechet,T. Kato. S. Ujiie and K. Timura. Anguw. Chem.,Int. Ed. Engl. 1992,31. 1531. I' €1. Poths G. Anderson K. Sharp and R. Zentel. Ah.Muter. 1992 4 792. 12 J. Chojnowski and K. Rozga J. Inory. Organomet. Polym. 1992 2 297. Inorganic and Organometallic Polymers THF using lithium silanolates as initiators (Equation 1). The monomer with a pendant ethyldiphenylphosphino group was prepared uia the AIBN promoted addition of diphenylphosphine to pentamethyl(viny1)cyclotrisiloxane.Oxidation and sulfuriz- ation yielded the monomers with pendant phosphorus(v) moieties. Depolymerization and chain scrambling processes were identified. These led to the isolation of polymers in which the organophosphorus side groups were not uniformly distributed on every third skeletal silicon atom.Treatment of the phosphine polymers with methyl iodide yielded quaternized polymers which function as polyelectrolytes. Me‘!(CH2h-PPh2X o/sl. 0 n II Me-Si Si-Me ’0’ Me Me/ Me Me (YH2h XPPh (3) X = lone pair 0,or S In the past year Zeldin and co-workers have reported details of the synthesis of water-soluble polysiloxanes with pendant 1-oxypyridin-3-yl groups (4). These polymers were prepared via polycondensation of the dialkoxysilane monomers. (4) Because of the unique material properties which arise from the presence of a polymer backbone containing alternating silicon and oxygen atoms the conformation and dynamics of polysiloxanes continue to be a subject of widespread interest.For example both molecular dynamics simulations and solid-state 29Si NMR studies of these aspects of polysiloxanes have been reported in the past year.l4.l5 3 Polyphosphazenes Significant advances continue to be made in the development of the phosphazene16.” polymer system. In particular new synthetic pathways to polyphosphazenes that complement or may show advantages over the previously reported routes are attracting current attention. De Jaeger and co-workers have reported’’ full details of the development of a route to poly(dichlorophosphazene) [NPCI,], involving the 13 M. Zeldin S. Rubinsrtajn. and W. K. Fife. J. Inory. Orymmnet. Polyrn. 1992 2 319. l4 N. Neuburger. I. Bahar. and W. L. Mattice Macromolecules.1992. 25 2447. Is T. Takayarna and I. Ando J. Mol. Struct. 1992. 271 75. 16 H.R. Allcock Chem. Eng. News. 1985. 63 (11). 22. l7 R. H. Neilson and P. Wisian-Neilson. Chem. Rev.. 1988. 88 541. G. D’Halluin. R. De Jaeger. J. P. Chambrette and Ph. Potin. Mac,romolecules. 1992 25 1254. 96 I. Manners solution polycondensation of P-trichloro-N-(dichlorophosphoryl)monophosphazene Cl,P=NP(O)Cl (Equation 2)which is currently being developed by Atochem. The advantages of this process involve the simple high yield synthesis of high-purity monomer the formation of gel-free polymers and the possibility of molecular-weight regulation. n C13P=N-P(O)C12 (2) + (n-1)P(O)Cl In another interesting development Matyjaszewski Nuyken et al.have reported the low temperature synthesis of poly( phenyl(trifluoroethoxy)phosphazene) (5) via the direct reaction of trimethylsilyl azide with bis(2,2,2,-trifluoroethyl)phenylphosphon-ite.lg The polymer is believed to be formed from phosphine azide intermediates. The polyphosphazene (5)formed is an amorphous stereorandom elastomer with a Tgof -31 "C (Equation 3). A similar synthesis of poly(diphenylphosphazene),[NPPh,], was also reported by Matyjaszewski and co-workers and this polymer is insoluble but shows interesting thermotropic liquid crystalline behaviour.,' Matyjaszewski has given an up-to-date review of the current status of the various synthetic routes to polyphosphazenes.2' Me,SiN -Me3Si(OCI (3) -N2 Interesting and important developments that extend the scope of the phosphazene polymer system continue to occur.For example full details have been reported by Allcock and co-workers on polyphosphazenes (6) that contain controlled short-chain branching.22 Kinetic studies of the polymerization of (7) indicated that the activation energy for the polymerization is about 46 kcal mol~ ',which is lower than most of the values suggested for the polymerization of hexachlorocyclotriphosphazene [NPCI,],. In general the glass transition values for poly(phosphazophosphazenes) are higher than those of classical polyphosphazenes. For example the Tgof (8)is -37 "C whereas that of [NPCI,] is -66 "C. In addition the tendency for the poly(phosphazophos- phazenes) to crystallize is lower. Hikichi and co-workers have reported that semicrystalline poly(bis(phenoxy)- phosphazene} displays two solid-state 31PNMR peaks which can be attributed to 19 K.Matyjaszewski R. Montague. J. Dauth. and 0.Nuyken. J. qj'folym. Sci.. Purr A:Polyn. Chern..1992. 30 813. 20 M. Cypryk K. Matyjaszewski M. Kojima. and J. H. Magill Mrrkromol. Chem. Rtrpid Commun.. 1992. 13. 39. 21 K. Matyjaszewski J. Inorg. Orgunomef. Polwn. 1992 2. 5. *' H. R. Allcock and D.C. Ngo. Macromolecules. 1992 25 2802. 97 lnorganic and Oryanometallic Polymers crystalline and amorphous regions.23 Similar studies of poly( bis(3-methyl- phenoxy)phosphazene} have also been reported by Haw and co-~orkers.~~ Gleria and co-workers have reported novel synthetic procedures for the preparation of polyphos-phazenes with hydroxyl f~nctionalities.~~ Full details of the synthesis of poly(phosphazene) blends and interpenetrating polymer networks with organic polymers have also been published in the past ear.'^.^' In addition Allcock has reviewed recent developments in polyphosphazenes,28 and Magill has reviewed the structure and morphology of poly(oxyphosphazenes).29 4 Polysilanes Polysilanes continue to attract intense interest from both fundamental and applied perspectives.The main method of preparing polysilanes involves the thermally induced Wurtz coupling reaction of dichlorosilanes with sodium metal. However the harsh conditions required for this reaction tends to limit the side groups that can be successfully incorporated and the procedure generally affords very low to moderate yields of high molecular weight polymer.The use of high-intensity ultrasound during Wurtz coupling reactions has been reported by Price to promote the formation of polysilanes with controlled molecular weight distribution^.^^ In addition Jones and co-workers have used reducing agents other than alkali metal such as yttrium and pyrophoric lead for the conversion of dichloromethylphenylsilane to p~ly(methylphenylsilane).~ The transition metal catalysed dehydrogenative route to oligosilanes discovered by Harrod et continues to attract intense attention from several research groups (Equation 4) and recent mechanistic advances have been reviewed by Tille~.~~,~~ The search for an understanding of the mechanism of this reaction and the development of new catalysts which may yield higher molecular weight products or stereoregular polymers are areas under intense current investigation.Recent advances in the 23 K. Takegoshi. I. Tanaka K. Hikichi and S. Higashida Mucromolecules 1992 25. 3392. 24 S.A. Taylor J. L. White N.C. Elbaum R. C. Crosby G.C. Campbell J. F. Haw and G.R. Hatfield Mucromolrcules. 1992. 25 3369. 25 A. Medici. G. Fantin P. Pedrini M. Gleria. and F. Minto Muuomolecules 1992. 25 3569. 26 H. R. Allcock K. B. Visscher and I. Manners Chem. Muter. 1992 4 1188. *' H. R. Allcock and K. B. Visscher Chem. Muter. 1992 4 1182. *' H. R. Allcock J. Inorg. Orgunomet Polym.. 1992 2 197. 29 J. H. Magill J. 1nor.g. Orgunomet. Polym.. 1992 2 213.30 G.J. Price J. Chem. Soc. Chem. Commun. 1992. 1209. 31 R. E. Benfield R. H. Cragg R. G. Jones and A.C. Swain J. Chem. SOC..Chem. Commun.. 1992 1022. 32 J. F. Harrod. Y. Mu and E. Samuel Polyhedron. 1991 10. 1239. 33 H.-G. Woo J.F. Walzer and T.D. Tilley J. Am. Chem. Soc.. 1992. 114. 7047. 34 T. D. Tilley. Ace. Chern. Rrs.. 1993. 26. 22. I. Manners synthesis of polysilanes with controlled polymer structures have been reviewed by Mat yjaszews ki . ’ Recent developments in polysilane chemistry such as the synthesis of ordered and disordered copolymers and liquid crystalline materials have been reviewed by West,3h and detailed studies of the solid state thermochromism and piezochromism of polysilanes have been reviewed by S~hilling.~’ The latter author has also reported studies of the structures and properties of polysilane copolymers with dimethylsilylene and di-n-hexylsilylene repeat units.38 An X-ray structure determination of the low-temperature phase of poly(di-n-hexylsilane) has been reported in the past year and this polymer was shown to possess an all-trans backbone conformation which is attributed to the intermolecular interactions present.39 5 Other Polymer Systems Based on Main Group Elements The synthesis and development of new polymer systems containing main group elements in the polymer main chain continues to attract considerable attention.Full details of the synthesis characterization and properties of a new class of sulfur-phosphorus-nitrogen polymers the poly(thionylphosphazenes) which were first reported in 1991 have been published by Manners and Vancso and co-workers in 1992.40 These polymers possess skeletal four coordinate sulfur(v1) atoms in addition to phosphorus and nitrogen and were synthesized via the thermal ring-opening polymerization of the cyclic thionylphosphazene NSOCl[NPCI,] ,or the fluorinated analogue NSOF[NPCl,],.The resulting polymers (9) undergo regiospecific substitu- tion of the chlorine atoms at phosphorus with sodium aryloxides to yield polymers (10) in which S-CI or S-F bonds remain intact (Scheme 1). The studies showed that the presence of skeletal sulfur(v1) atoms in the polymer backbone gives rise to interesting differences from classical polyphosphazenes in terms of material properties such as glass transition behaviour and polymer morphology; in addition differences with respect to reactivity patterns and consequently the polymer structures that are accessible have also been found.Initial studies4’ of the polymeriz- ation mechanism for cyclic thionylphosphazenes suggest a cationic chain growth process with ionization of the S-Cl bond as the initiation step. Propagation is proposed to occur by attack of the generated thionylphosphazene cation on another monomer molecule (Scheme 2). 35 K. Matyjaszewski J. Inorg. Orgunomet. Polym. 1992. 2. 5. 36 R. West R. Menescal. T. Asuke and J. Eveland J. Inorg. Orgunomet. Polym. 1992 2 29. 37 R.C. Schilling A. J. Lovinger D. D. Davis. F. A. Bovey. and J. M. Zeigler J. Inorg. Orgunomet.Polym. 1992 2 47. 38 F. C. Schilling A. J. Lovinger D. D. Davis. F. A. Bovey and J. M. Zeigler Mucromolecules 1992.25. 2854. 39 S. S. Patnaik and B. L. Farmer Polymer 1992 33. 4443. 40 Y. Ni A. Stammer M. Liang. J. Massey G.J. Vancso. and 1. Manners Mucromolecu1r.s. 1992 25 71 19. 41 M. Liang C. Waddling. C. Honeyman D. Foucher and I. Manners. Phosphorus Suifur und Silicon arid Re[. Elem. 1992 64 113. Inorgunic und Orgunometullic Polj'mers X = C1 or F (9) X = CI or F Na[OAr] Scheme 1 Initiation 0 c1 0 a-\\ 1 \\ + N NA "S N II I II I c1-P ,P-Cl CI-P ,P-Cl c1/ \Cl c1/ * \Cl Propagation c1 c1 0 I I II 0 N=P-N=P-N=S+ \\ / I I I II I N II Y -II I c1 c1 c1 Cl-P ,P-Cl c1-P ,P-CI c1-P ,p-a c1/ \Cl c1/ 'Cl c1/ 'a Scheme 2 Preliminary details of the synthesis of the first poly(oxothiazenes) (1 1) with alkyl or aryl side groups at sulfur was reported in 1992 by Roy.42 These polymers were produced uiu the condensation polymerization of N-silylsulfonimidates (Equation 5) and appear to possess significantly higher glass transition temperatures than the analogous polyphosphazenes.For example the Tgof [MeS(O)=N], is 55-65 'C whereas that of [Me,P=N], is -46°C. 42 A. K. Roy J. Am. Chem. Soc. 1992. 114 1530. 100 I. Manners R =Me or Ph (11) The synthesis and study of c/n conjugated ethynylenedisilanylene copolymers (12) was reported by Ishikawa and Tsukihara and co-workers in Japan. The synthetic procedure involved the ring-opening polymerization of tetrasilacyclodiynes (Equation 6).43Anionic catalysts such as BuLi were found to be effective for the polymerization in THF.The polymers (12) formed possessed weight-average molecular weights (M,) of between ca. 6.5 x lo4 and 1.2 x lo5.Because of the presence of skeletal Si-Si bonds the polymers are photoactive and moreover treatment of films of several of the polymers with SbF yielded materials with slight to appreciable electrical conductivity (1 x 10- '-2 S cm-'). The mechanism of conduction is postulated to involve removal of an electron from a Si-Si bonding orbital and delocalization of the resulting electron hole through the o/nsystem. The mechanism for the ring-opening polymerization is believed to involve nucleophilic attack at silicon to give a ring-opened species that subsequently reacts with another molecule of the monomer in the chain propagation step.R R I I R -Si-C=C-Si-R catalyst ___f I I R-Si-CS-Si-R I I n R R Ishikawa and co-workers have prepared novel unsaturated organosilicon polymers (13) containing disilane and conjugated C=C and C=C units using a rhodium(1) catalysed head-to-head coupling of diethynylsilanes (Equation 7).44 The weight- average molecular weights of the polymers were in the range 104-105. The polymers were highly photoactive both in the solid state and in solution due to the facile scission of the Si-Si bonds in the polymer backbone with UV light. The polymers could be doped to yield electrically conducting films with SbF the conductivity values were 10p3-l Scm-' in air and ca.10p4-10-3Scm-' in uucuo. Unsaturated silicon- and germanium-containing polymers have also been syn- thesized by Tanaka and co-workers using condensation routes and were shown to possess conductivities of ca. 10-4Scm-' after doping with AsF,.~ The same researchers have reported that polymers containing skeletal disilane units can be modified by the palladium catalysed insertion of acetylenes into the backbone Si-Si 43 M. Ishikawa T. Hatano Y. Hasegawa T. Horio A. Kunai A. Miyai T. Ishida T. Tsukihara T. Yamanaka T. Koike and J. Shioya Organometallics 1992 11 1604. 44 J. Ohshita A. Matsuguchi K. Furumori R.-F. Hong M. Ishikawa T. Yamanaka T. Koike and J. Shioya Macromolecules. 1992 25 2134. 45 T.Hayashi Y. Uchimaru. N. P. Reddy and M. Tanaka Chem. Lert.. 1992 647. inorganic and Oryanometullic Po/>Jmers bonds.46 The electronic structure of polymers containing n-conjugated units and silicon atoms has been analysed the~retically.~' The pyrolysis of silicon-containing polymers to yield ceramics is attracting continuing attention. Corriu and co-workers have investigated the pyrolysis chemistry of polymers of structure (14)and have reported that treatment at 1400"C under argon affords a p-Sic containing ceramic in 84% yield whereas pyrolysis under ammonia yields Si3N4.48.49 Doping of these polymers with FeCl gave materials with conductivities in the 10-5-10-3S cm-range. Other developments in the general area of polymers containing Group 14 elements include the synthesis of novel silane dendrimers using repeated alkenylation-hy- drosilylation cycles reported by van der Made and van Leeuwen," and the discovery of a novel electroreductive synthesis of polygermanes and polygermane/polysilane copolymers which has been described by Shono et ~1.~' Weber and co-workers have reported the anionic ring-opening polymerization of benzosilacyclobutenes and have described the ring-opening polymerization of silacyclopentenes with vinyl groups at ~ilicon.~~.~~ Rao et al.have reported the synthesis of poly(tetramethyldisily1ene-co-styrene) uia the reaction of dimethyldichlorosilane with sodium metal at 1 10"C in toluene in the presence of styrene.54 In addition the first preliminary report of high molecular weight polystannanes via a Wurtz coupling procedure has also been published.55 The structure of such polymers has been analysed the~retically.'~ Interesting developments involving boron-containing polymers have been reported in the past year.Chujo and co-workers have reported a novel allylboration polymerization methodology which provides a route to air and moisture stable " H. Yamashita and M. Tanaka. Chem. Lott. 1992 1547. " K. Tanaka. K. Nakajima M. Okada. T. Yamabe and M. Ishikawa 0rqanometallic.s. 1992 11 3191. '' J. L. Brefort R. J. P. Corriu Ph. Gerbier. C. Guerin. B. J. L. Henner A. Jean Th. Kuhlmann F. Gamier. and A. Yassar. Orqunomerullics. 1992. 11 2500. 4y R. J. P. Corriu P. Gerbier C. Guerin. B. J. L. Henner A. Jean and P. H. Mutin Orgunometallics 1992 11.2507. so A. W. van der Made and P. W. N. M. van Leeuwen. J. Chem. Soc. Chem. Commun. 1992. 1400. '' T. Shono. S. Kashimura and H. Murase J. Cheni. Soc. Chem. Commun. 1992 896. '' S.J. Sargeant S.Q. Zhou G. Manuel and W. P. Weber. Macromolecules 1992 25 2832. M. Theurig S. J. Sargeant. S.G. Manuel and W. P. Weber .Macromolecules. 1992. 25 2834. s4 M. R. Rao. S. Packirisamy P. V. Ravindran and P. K. Narendranath Macromolecules 1992. 25 5165. " W.K. Zou and N.-L. Yang Poljimer Prepr. (Am. Chem. Soc. Dic. Polynr. Chem.) 1992 33 188. " K. Takeda and K. Shiraishi Chem. Phqs. Letr. 1992 195 121. 102 I. Manners cycloborazane polymers (1 5).57Their reaction procedure is shown in Equation 8 and the resulting polymers possessed a weight-average molecular weight (M,) of 25 700.The development of boron-nitrogen based polymers as precursors to ceramics is attracting continuing attention and this has been reviewed by Paine.58 In a significant development in silicon-nitrogen polymer chemistry Soum and co-workers have reported that the ring-opening polymerization of certain cyclo- disilazanes (16)occurs using cationic or anionic initiators to yield the first examples of high molecular weight (M = ca. 10") white crystalline polysilazanes (17).59Polymers were prepared from cyclic disilazanes when the substituent at nitrogen was a methyl group and moreover under anionic initiation the polymerizations were found to be living. In contrast to cyclodisilazanes with methyl groups at nitrogen cyclodisilazanes with larger substituents at nitrogen yielded only oligomers under the same reaction conditions and both cyclotrisilazanes and cyclotetrasilazanes were found to be resistant to polymerization.R R\ . R-S-N' II N-Si,-R R' R 6 Polymers Containing Skeletal Transition Metal Atoms The area of transition metal based polymer science is attracting growing interest. Attention continues to be focused on poly(metallaynes) remarkable macromolecules (such as (18))with backbones which possess conjugated C=C and transition metal atoms. In the past year Lewis and co-workers at Cambridge have reported the synthesis of crosslinked platinum polyyne polymers" and Lewis Marder Friend and co-workers have described the synthesis of platinum polymers (19)with only acetylenic groups in the polymer main chain." " Y.Chujo. I. Tomita. and T. Saegusa. Mucromolecules 1992. 25. 3005. '* R. T. Paine. J. Inorg. Orgunornet. Polym. 1992 2 183. E. Duguet. M. Schappacher and A. Soum Macromolecules 1992 25 4835. 6o M.S. Khan D. J. Schwartz N. A. Pasha A. K. Kakkar. 8. Lin. P. R. Raithby. and J. Lewis Z. Anorg. Allg. Chrm.. 1992 616. 121. 6' J. Lewis M. S. Khan A. K. Kakkar B. F. G. Johnson,T. B. Marder H. B. Fyfe F. Wittmann R. H. Friend and A. E. Dray. J. Orgunornet. Chem.. 1992 425. 165. inorganic and Oryanometallic Poljwers Hunter and co-workers have reported a successful synthesis of the arene bridged organometallic polymer (20) by using the condensation metathesis reaction of 4,4’-dilithioperfluorobiphenyl with NiBr,(PMePh,) (Equation 9).62 These polymers are yellow materials but only lower molecular weight fractions with 5-10 repeat units were found to be soluble in THF.Characterization of these interesting polymers was facilitated by the study of discrete oligomers. From X-ray crystallographic studies of the latter it was concluded that skeletal octafluoro-p,p’-biphenylene linkages are poor candidates for the development of polymers with extended n-conjugation because of the substantial twist angle observed between adjacent aromatic rings which reduces n-overlap. r -LiBr ___t I [NiBr2(PMePh2)2] L Two interesting new classes of ferrocene-containing polymers were reported in 1992. Brandt and Rauchfuss reported the synthesis of polyferrocenylene persulfides cia a novel atom abstraction route.63 Thus reaction of the trithiaferrocenophanes with PBu led to the formation of S=PBu and the polymer (21) (Equation 10).The presence of a butyl group is necessary for the polymer to be soluble. The molecular weight (M,) of (21) was ca. 40000 by Gel Permeation Chromatography. Remarkably the polymers can be reversibly reductively cleaved and then regenerated on oxidation. Electrochemistry of the polymers (in CH,Cl,) showed the presence of two chemically reversible oxidation waves separated by 0.32V which was attributed to the first oxidation occurring at alternating iron sites along the polymer chain. Manners and co-workers reported the synthesis of the first examples of high molecular weight poly(ferrocenylsi1anes) (23) via the thermal ring-opening polymeriz- ation of [l]ferrocenophanes (22) containing a single silicon atom in the bridge (Equation I 1).64 The latter compounds possess a strained structure in which the planes of the cyclopentadienyl ligands are tilted by ca.21 “C relative to one another. When the h2 K.C. Sturge. A. D. Hunter. R. McDonald and B. D. Santarsiero Orytrnometullics. 1992. 11. 3056. h3 P. F. Rrandt and T.R. Rauchfuss J. Am. Chem. Soc. 1992. 114 1926. 64 D.A Foucher B. Z Tang and I. Manners. J. Am. Chem. Soc.. 1992. 114 6246. 104 I. Munners *sr (R = H Bu") cyclic ferrocenylsilane (22 R = Me) was heated at elevated temperatures ring-opening polymerization to yield the amber soluble poly(ferrocenylsi1ane) (23 R = Me) with M = 520 000 and M,= 340 000 was observed.Polymer (23 R = Me) displays two reversible cyclic voltammetric oxidation waves in CH,CI (separated by 0.16V at a scan rate of 25 mV s-). The phenylated cyclic ferrocenylsilane (23 R = Ph) was also found to polymerize. However in this case the polymer was found to be insoluble in common organic solvents although the material swelled appreciably in N-methylpyr- rolidone. Monitoring of the polymerization by differential scanning calorimetry allowed the strain energies of the cyclic ferrocenylsilanes (22) to be estimated and these were found to be cu. 60-80 kJ mol-'. heat __c Wright and co-workers have reported the synthesis of a variety of organometallic polymers which contain ferrocene groups in the polymeric main-chain or side-group structure using condensation These materials were prepared because of their potential use as non-linear optical materials and in one case f2) effects were demonstrated and a second harmonic generation efficiency four times that of quartz was measured.65 As part of a program aimed at developing routes to polymers with photochemically reactive metal-metal bonds in the main chain Tenhaeff and Tyler have reported68 the synthesis and photochemistry of a polyurea with skeletal Mo-Mo bonds (24) and poly(ether urethane) copolymers (24) and (25) containing Mo-Mo and Fe-Fe bonds along the polymer backbone respectively.The polymers were synthesized oia condensation techniques and were found to undergo homolytic cleavage of the M-M '' M.E.Wright E.G. Toplikar R.F. Kubin and M.D. Seltzer Mar~romolecule.s,1992 25 1838 " M. E. Wright and E. G. Toplikar. Macromolecules. 1992. 25,6050. 67 M. E. Wright and M. S. Sigman Mocromolrculrs. 1992 25. 6055. '' S.C. Tenhaeff and D.R. Tyler Organornetallic~s,1992. 11 1466. Inorganic and Organometallic Polymers bonds on photolysis. Evidence for this was provided by irradiation experiments carried out in the presence of CCl which yielded products of type Cl(CO),MoC,H,- R-C,H,Mo(CO),Cl and CI(CO)2FeC,H,-R-C,H,Fe(CO)2Cl. Other areas of transition metal polymer chemistry are also attracting attention. For example Puddephatt and co-workers have reported an interesting new method for the incorporation of metals into the side-group structure which involves the use of oxidative addition reaction^.^^ Metalled monomers and polymers were prepared cia the reaction of the 2-bromoethyl methacylate or poly(2-bromoethyl methacylate) with the platinum(I1) complex [PtMe,(bipy)].Polymeric coordination compounds containing skeletal transition metal atoms are also of continuing interest. For example Smutzler and co-workers have reported the synthesis of polymeric species with carbodiimide ligands and Serrano and co-workers have described studies of liquid crystalline polymers containing paramagnetic copper(I1) salicylaldiminates.70~7 * In addition Wynne has reviewed recent progress on phthalocyanine-containingpolymers.72 69 S. Achar J. D. Scott and R.J. Puddephatt Organometullics 1992 11 2325. 70 M. Gruber L. Heuer R. Schmutzler H. Maarmann. and H.-M. Schiebel Po/$whn. 1992. 11. 1099. 71 M. Marcos L. Oriol and J. L. Serrano. Macromolecules 1992 25 5362. 72 K. J. Wynne J. Inorq. Organomet. Polym. 1992 2. 79.

ISSN:0260-1818    

DOI:10.1039/IC9928900093

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

9 Ti Zr and Hf By S.A. COTTON Felixstowe College Maybush Lane Felixstowe Suffolk lP1 I 7NQ UK 1 Metallocarbohedranes The synthesis of metallocarbohedranes represents the most striking development in the chemistry of Ti Zr and Hf this year. Studies of the dehydrogenation of small hydrocarbons with a plasma of titanium revealed’ a superabundant stable cationic species at 528 amu shown by isotopic labelling to be a Ti8C, cluster. Similar clusters have been reported for Zr Hf and V and other reports have concerned Zr,,C,, Zr 8C29 and Zr,,C, which are believed to have multicage structure^.^,^ A pentagonal dodecahedra] structure has been suggested for the M clusters (Figure 1) consistent with ‘titration’ experiments in which eight ammonia molecules were taken up per cluster molecule indicating that all the titaniums were exposed on the surface of the cluster.This structure can also be viewed in terms of a cube of metal atoms face-capped by six C-C units. Several papers have discussed the bonding in the cluster^;^-^ one indicates a more stable structure (Figure 2) where six C units occupy Figure 1 Figure 2 (Reproduced with permission from J. Chem. Soc. Chrm. Commun. 1992 1779) B. C. Guo. K. P. Kerns and A. W. Castleman. Science. 1992. 255 141 I. B.C. Guo S. Wei J. Purnell S. Buzza and A. W. Castleman Science. 1992 256 515. S. Wei B. C. Guo J. Purnell S. Buzza and A. W. Castleman Science. 1992,256,818;J. Phys. Chem.. 1992. 96 4166. R. W. Grimes and J. D. Gale J. Chem. Soc.. Chrm. Commun. 1992 1222.M-M. Rohmer P. de Vaal and M. Benard J. Am. Chem. Soc. 1992 114 9696. Z. Lin and M.B. Hall J. Am. Chem. SOC.,1992 114 10055. ’ I. Dance J. Chrm. Soc. Chrm. Commun.. 1992 1779. ’ L. Pauling. Proc. Nat. Acad. Sci. U.S.A.. 1992 89. 8175. 107 108 S.A. Cotton the butterflies of a Ti tetracapped tetrahedron. A triplet ground state which may exhibit Jahn-Teller distortion is predicted. Using valence-bond theory however Pauling has predicted a cubic structure with flat faces.' 2 Halides and Halide Complexes Several reports again concern fluoro complexes. (NH,)ZrF is isostr~ctural~ with TlZrF whilst the corresponding hydrate has polymeric chains with ZrF,(H,O) coordination; CsZrF,(H,O) is similar. lo CsSZr,F,,.3H,0 has tetrameric chains' ' whilst Cs6Hf6F,,-4H,0 has individual [HfF6I2- ions in addition to the chains and BaZr,Flo.2H,0 has chains with trigonal dodecahedra1 coordination.' The range of compositions of zirconium and hafnium fluoro complexes has been extended.' BaTiOF has cis-connected TiO,F coordination' whilst several hexachlorozircon- ates have been reported." TiCl complexes with a variety of ligands (alcohols pyridines nitriles thf) and their thermal decomposition has been studied,I6 whilst [{ZrCl,(PBu,),},] reacts with pyridines to give dimeric [{ZrC13(4-R-py),},] (R = H CMe, 1-butylpentyl) with short Zr-Zr distances indicating a single bond.' The pyridine complex oxidatively adds Me,CCN to afford a dimer with bridging nitriles (1). [Zr(NCMe),Cl,][FeCl,] has distorted square antiprismatic coordination ge- ometry in the cation.' Tertiary phosphines react" with [ZrCl,(thf),] either by substitution (2 PMe,) or by nucleophilic ring-opening (3 PCy or PPh,). CMe3 I c1 PMe3 PR3 (2) V.V. Tkachev R.L. Davidovich and L.O. Atovmyan Koord. Khim. 1991 17 1483. lo V.V. Tkachev A.A. Udovenko R. L. Davidovich and L.O. Atovmyan Koord. Khim. 1991 17 1635; V. V. Tkachev R.L. Davidovich and L.O. Atovmyan Koord. Khim. 1992 18 38. I' V. V. Tkachev R. L. Davidovich and L. 0.Atovmyan Koord. Khim. 1992 18,42; A. V. Gerasimenko B.V. Buvetskii V.B. Logvinova and R. L. Davidovich Koord. Khim. 1991 17 1485. Y. Gao J. Guery A. Le Bail and C. Jacoboni J. Solid Stare Chem. 1992 98 11. l3 R. L. Davidovich V. B. Logvinova and L.V. Teplukhina Koord. Khim. 1992 IS 48. l4 M. P. Crosnier and J. L. Fourqeet Eur. J. Solid State Inorg. Chem.. 1992 29 199. L. Buscaglioni and H. Sutcliffe J. Alloys Compounds. 1992 185 67. l6 M. Kohutova and M. Zikmund Transition Met. Chem. 1992,17 186; M. Kohutova A. Valene and M. Zikmund Acfa Fac. Rerum. Nat. Uniue. Cornenianae Chim.. 1991 39 121. (Chem. Abstr. 117 84204). D. M. Hoffmann and S. Lee Inorg. Chem. 1992 31 2675. B.I. Kharisov S.I. Troyanov and S.S. Berdonosov Koord. Khim. 1991 17 1473. l9 T. L. Breen and D. W. Stephan Inorg. Chem. 1992 31 4019. Ti Zr and Hf 109 Interest continues in Zr clusters. Centred isolated zirconium clusters are found in2' Rb,Zr,Cl 8C and Li,Zr,Cl 8H whilst electronic spectra have been recorded and extended Huckel calculations carried out for [Zr,Cl,,Z]"~ (Z = B Be Fe).21 Syntheses and structures have been reported for a number of Zr,X,,(PR,) systems (X = C1 Br; R = Me Et Pr etc.).Bond lengths depend on the position in the cluster as well as upon the halogen.22 3 Aqua Ions and Similar Solvated Species Several studies have appeared in this area.The contact contribution to electronic relaxation of the hexa-aquatitanium(rr1) ion has been assessed by NMR dispersion measurements2 whilst dmf exchange in the corresponding dmf solvate has been shown to occur by an associative route., The solvation structure of titanium(1rr) ions in methanol has been probed by ESR; ENDOR25 and NMR have been used to investigate2 the mechanism of axial and equatorial site exchange in [TiO(dmso)J2+.4 Binary Compounds Interest in simple binary compounds is often inspired by applications in materials science.An ah initio study of bonding in rutile-type compounds has appeared,27 whilst linking TiO with an iron porphyrin leads to a catalyst for the photo-oxidation of hydrocarbons under mild conditions.28 TiO catalyses the photo-oxidation of methylaromatics in the presence of silver sulfate.29 Interest in TIN as a material for wear-resistant coatings particularly in microelectronics has led to the study of its preparation in thin films from amide" and amine3' complexes. Titanium diboride has been prepared by cathodic deposition from melts,32 by laser-induced hydrogen reduction of TiCl,/BCl mixtures,, and by reaction of boron with titanium alk~xides.~~ Mercury intercalation of titanium disulfide has been 5 Other Complexes The structure of Cs,[TiO(C20,),]~2H,0 involves tetranuclear anions with six- coordinate titanium., Various titanium(1v) triflate species have been reported,37 J.Zhang R. P. Ziebarth and J. D. Corbett Inory. Chem. 1992 31 614. '' M. R. Bond and T. Hughbanks Inorg. Chem. 1992 31 5015. 22 F.A. Cotton X. Feng M. Shang and W.A. Wojtczak Anyew. Chem.. Int. Ed. Engl.. 1992 31 1050. 23 1. Bertini C. Luchinat and 2. Xia Inorg Chem.. 1992 31 3152. 24 I. Dellavia. L. Helm and A. E. Merbach. Inorg. Chem. 1992 31 2230. 2s S. Schlick and B. E. Myers Z. Naturforsch. Teil A 1992 47. 702. '' I. Dellavia L. Helm and A. E. Merbach. Inorg. Chem.. 1992 31 4151. '' P.Sorantin and K. Schwarz. Inory. Chrm.. 1992. 31 567. 28 R. Amandelli M. Bregola E. Polo V. Carassiti and A. Maldotti J. Chem. Sot. Chem. Comrnun. 1992 1335. '' E. Baaciocchi G. C. Rosato. C. Roi and G. V. Sebastiani Tetrahedron Lett. 1992 33 5437. ") C. H. Winter P. S. Sheridan T. S. Lewkebandara M. J. Heeg and J. W. Proschia J. Am. Chem.Soc. 1992 114 1095. 31 M. E. Gross and T. Siegrist Inory. Chem 1992 31 4898. 32 H.G. Wendt K. Reuhl. and V. Schwartz. J. Appl. Electrochem. 1992 22. 161. 33 J. Elders and J. D. W. Van Voorst. Appl. Surf. Sci.. 1992 54. 135. 34 Z. Jiang and W. E. Rhine Chem. Muter.. 1992. 4 497. 35 E. W. Ong M. J. McKelvey G. Ouvrard and W. S. Glausinger Chem. Muter.. 1992 4 14. 3h A. Facer. W. Bensch and W. Troemal Inorg. Chim. Actu 1992 193 99.37 H. Moulay el Moustapha and J. L. Pascal J. Fluorine Chem.. 1991. 55 63. 110 S.A. Cotton ~ including [Ti(OTf),] '. Macrocyclic complexes have included a crown ether titanoxane (Figure 3) with the cation3* [(TiCl( 12-cro~n-4)0),]~+ TiCl and TiC1 9C(12) b Figure 3 (Reproduced with permission from J. Chem. Soc. Dalton Trans. 1992 1 117) complexes with a substituted triazacycl~nonane,~~ and the 0x0-bridged [{ LM(acac),)0][C10,] (L = 1,4,7-triaza~yclononane).~~ Schiff-base complexes have attracted attention;,l in particular alkylation of [TiCl,(salen)] gives thermally labile trans-[TiMe,(salen)] which undergoes methyl migration to the Schiff base., These reactions are very solvent-dependent and in thf reductive arylations to afford the titanium(n1) compounds [TiR (thf)(salen)] (R = Ph mes) are observed.Mixed Ti(1v) complexes with dithiocarbamate and methyl salicylate ligands have been reported.43 A most interesting example of trigonal monopyramidal coordination is found in [Ti(N,N)] (N3N = [(Bu'Me,Si)NCH,CH,],N) (4),made by sodium amalgam reduction of the (presumably) trigonal bipyramidal Ti" compound [TiCl(N,N)] .44 The related titanium(rv) complex [TiCl{ N(CH,CH2NSiMe3),}] can be converted into isolable butyls; the sec-butyl cleanly metallates on heating or on reaction with dihydr~gen.~~ Six-coordinate zirconium and hafnium trimethyls (5) have been 38 G. R. Willey J. Palin and N. W. Alcock J. Chem. Soc ,Dalton Trans. 1992 1117. 39 A. Bodner P. Jeske T. Weyhermueller K.Wieghardt. E. Dubler H. Schmalle and B. Nuber Inorg. Chem. 1992 31 3737. 40 P. Jeske K. Wieghardt B. Nuber and J. Weiss Inorg. Chim. Actu 1992 193. 9. 41 A. De Blas R. Bastida and M. J. Fuentes Synth. React. Inorg. Metallo-Org. Chem. 1991 21 1273 42 E. Solar] C. Floriani. A. Chiesi-Villa. and C. Rizzoli J. Chem. Soc. Dalton Trans. 1992 367. 43 S. Bhargava R. Bohra and R.C. Mehrotra Transition Met. Chem. 1991. 16. 622. 44 C.C. Cummins J. Lee R. R. Schrock and W. D. Davis Angew. Chem. Int. Ed. Engl. 1992 31 1501. 45 C. C. Cummins R. R. Schrock. and W. M. Davis Organometallics 1992 I I 1452. Ti,Zr and Hf 111 synthesized and the crystal structure of [Hfh4e3{N(SiMe,CH2PMe2),)] has been determined.46 The structure of [Zr(oep),].2dmso confirms the double-decker structure; the dimethylsulphoxide molecules do not ~oordinate.~' Oxidation of the zirconium and hafnium bis(porphyrin) complexes to the mono and dicationic [M(porph),]"+ (n = 1,2) has attracted at ten ti or^;^^.^^ the electron spins in the diamagnetic dications [Zr(porph),12+ are strongly coupled.Crystallographic data confirm the progressive shortening of the interporphyrin distance with concomitant increase in the n-n interaction in moving from neutral to dicationic zirconium tetraphenylporphyrin complexes. [ZrCl,(oep)] has been ~ynthesized;~~ the two halogens can be replaced by a range of substituents (alkyl aryl alkoxy carborane cyclooctatetraenyl; Figure 4); the structures of the carborane5' 'sandwich' [Zr(oep)(C,B,H )] and the dialk~l~~ [Zr( CH,SiMe3 )*(oep)] were determined.>I' 7 R-H R-H RIM R-Me Figure 4 (Reproduced with permission from J. Am. Chem. Soc. 1992 114 2266) An eight-coordinate zirconium Schiff-base complex with two reactive isocyanate groups forms a co-polymer with p~ly(thf).~l Ethylenedioxydiethylenedinitrilotet- raacetic acid (H,egta) forms complexes [M(egta)] with zirconium and hafnium that are isostructural in the solid state but exhibit significantly different NMR beha~iour.~ 46 M.D. Fryzuk A. Carter and S.J. Rettig. Organometallics. 1992 11 469. 41 J. W. Buchler A. De Cian S. Elschner J. Fischer P. Hammerschmitt and R. Weiss Chem. Ber. 1992 125 107. 48 H-J. Kim D. Whang J. Kim and K. Kim Inorg. Chem.1992 31. 3882. 49 H. Brand and J. Arnold J. Am. Chem. Soc. 1992 114 2266. 50 J. Arnold S.E. Johnson C. B. Knobler and M. F. Hawthorne J. Am. Chem. Sac. 1992 114 3996. 51 W. Tong and R.G. Archer Inarg. Chem.. 1992 31 3332. 52 D. F. Evans G.W. Griffiths C. O'Mahoney D. J. Williams. C Y. Wong and J. D. Woollins J. Chern. Soc. Dalton Trans. 1992. 2475. 112 S. A. Cotton 6 Alkoxides Amides and Related Compounds These continue to be of intere~t~~.~~ because of their use in the synthesis of mixed metal oxides like BaTiO, by sol-gel reactions. Several titanium(rI1) aryloxides have been synthesized and structurally characterized (Figure 5);55an electron-diffraction study trans-[TiC12(tmeda)2] I 2RONa R=Ph R = 3,5-(But)2Ph I I R R R R R R R R M = Na(tmeda)2(thf) [(RO),Ti ] [Li(1 tmedah] 4 L i = tmeda-H Figure 5 (Reproduced with permission from Inory.Chem. 1992 31 4933) of [Ti(NMe,),] has been reported56 and a five-coordinated tertiary phosphine adduct of a titanium aryloxide q2-ketone complex has been structurally ~haracterized.~' 53 J. P. Grammatico and J. M. Porte Lopez J. Muter. Sci Muter. Electron.. 1992 3 82. 54 vide M. Yoshimura S. E. Yoo M. Hayashi and N. Ishiwara Ceram. Truns.. 1990 15 427. 55 R. Minhas R. Duchateau S. Gambarotta and C. Bensirnon Inorq. Chem. 1992 31 4933. s6 A. Haaland K. Rypdal H. V. Volden and R.A. Andersen J. Chem. Soc. Dalton Trans.. 1992 891. 57 J.E. Hill. P.E. Fanwick and I.P. Rothwell Orqanometullics 1992 11 1771. Ti,Zr and Iif Hydrolytic reactions have led to the characterization of clusters such [Zr,Ti,(OPr)l,(OAc),o6] [Ti,O,(OEt)8(methaCrylate)8] [TiI8O,,(OBU),,-(acac),] (Figure 6) and [Zr ,FeO(OC,H,) Jacac),] .Figure 6 (Reproduced with permission from Compt. Rend. Acad. Sci. Series 11 1991 313 1247) Titanium-oxo clusters are also reported6 from the reaction of carboxylic acids with TiCI,; the structure of [Ti,CI,(O,CPh),),] has a Ti,O core. [Zr(OR [R = (CF,),CH)] has been synthesized6 and reacted with [TI(OR,)] to give TI,[Zr(OR ),I; the latter has a molecular structure based on a [Zr(OR ),I octahedron with thallium atoms occupying opposite trigonal faces. Syntheses structures and dynamics of several titanium(1v) binaphtholates have been explored.64 The first homoleptic tellurolates [M(TeSi(SiMe,),}] have been reported6’ whilst the reaction of [TiCl,(tmeda),] with LiN(SiMe,) under nitrogen leads to unexpected dinitrogen complexes including, (6).The replacement by titanium of either one or two boron ring atoms in the preparation of borazine analogues has been reported;67 polyamidoimidonitride clusters of zirconium have also been characterized.68 58 I.Lazziz A. Larbot A. Julbe C. Guizard and U. Cot J. Solid State Chem. 1992 98 393. 59 U. Schubert. E. Arpac W. Glaubitt A. Helmerich and C. Chau. Chem. Marer. 1992 4 291. 60 P. Toledano M. In and C. Sanchez Compt. Rend. Acad. Sci.. Ser. 11 1991 131 1247. 61 R. Schmid H. Ahamdane and A. Mosset Inorg. Chim. Acta 1991 190 237. 62 N. W. Alcock D.A. Brown S. M. Roe and M. G. H. Wallbridge,J. Chem.Soc. Chem.Commun. 1992,846. 63 J.A. Samuels J. F. Zwanziger E. B. Lobkovsky and K. G. Caulton Inorg. Chem. 1992 31 4046. 64 T.J. Boyle D. L. Barnes. J. A. Heppert L Morales F.Takusagawa. and J. W. Connolly Organornetallics 1992 11 1112. 65 V. Christou and J. Arnold J. Am. Chem. Soc. 1992 114 6240. 66 N. Beydoun R. Duchateau and S. Gambarotta J. Chem. Soc. Chem. Commun. 1992 244. 67 H.-J. Koch H. H. Roesky R. Bohra M. Noltemeyer and H.-G. Schmidt .4ngew. Chem. In[. Ed. Engl. 1992 31 598. 68 M. M. B. Hall and P.T. Wolczanski d. .4m. Chem. Soc. 1992 114. 3854. ) 114 S.A. Cotton Me3Si PY PY Me3Si-N.,. I I /Cl ,Ti-N-N-Ti; c1 I I N-SiMe, IiY py 'SiMe 7 Phosphates and Related Systems The structure of titanium(II1) phosphate has been determined.69 Potassium titanyl phosphate (KTP; KTiOPO,) is an important ion-conducting non-linear optical material; the effects of a d.c.electric field on its structure have been e~amined,~' whilst the effect of cation substitution upon its structure and optical properties has been e~plored.~ Zirconium phosphates continue to attract attention for their potential for supra- molecular assembly for example and have been reviewed together with other phosphates and phosphonates.72 Syntheses have been reported for chromia-pillared a-zirconium phosphate,73 sodium zirconium phosphate^,?^ and zirconium phosphate hypophosphites and dimethylphosphinate~.~~ The protonic conductivity of layered zirconium phosphonates with -S03H groups has been e~amined,'~ whilst solid state NMR has been used to extract structural information on oriented zirconium bis(phosponoacetic Intercalates of zirconium phosphates and phosphonates have been re~iewed;~' amine intercalates of r-zirconium phosphate have been studied by 31PNMRe7' A study of zirconium phosphate intercalated by organic bases (e.y.phen bipy) showed that the interlayer distance was not a simple function of the size of the guest molecules; iron (11) complexes formed by the intercalated donors" were also studied. Chiral molecular recognition on intercalation has been investigated8 whilst a halide-viologen complex trapped in a zirconium phosphonate matrix has applications in solar energy storage.82 69 R.Glaum and R. Gruehn Z. Kristallogr. 1992 198 41. 70 M. T. Sebastian H. Klapper and R. J. Bolt J. Appl. Crystaloyr. 1992 25 274. 71 M. L. F. Phillips W. T. A. Harrison. G. D. Stucky E. M. McCarron J. C. Calabrese and T. E. Gier Chem. Mater. 1992 4 222. 72 G. Cao H.-G. Hong. and T.E. Mallouk. Ace. Chem. Res. 1992 25 420. 73 P. Mairles-Torres P. Olivera-Pastor E. Rodriguez-Castellon A. Jiminez-Lopez. and A. A. G. Tomlinson J. Mater. Chem. 1992 1 139. 74 M.K. Dongare P. Singh and P. M. Suryavanshi. Maw. Res. Bull. 1992 27! 637. 75 G. Alberti M. Casciola and R. K. Biswas Inorg. Chim. Acta. 1992 201 207. 76 G. Alberti M. Casciola U. Costantino A. Peraio and E. Montoneri Solid Stare lonics 1992 50 315. 77 D.A. Burwell K. G. Valentine J. H.Timmermans and M. E. Thompson J. Am. Chrm. Soc. 1992. 114 4144. 78 G. Alberti and IJ. Costantino Inclusion Compd. 1991 5. 136. 79 D. J. MacLachlan and K. R. Morgan J. Phys. Chrm. 1992 96 3458. Ro I. Tomita K. Sasaki R. Inoue Y. Morino Y.Hasegawa M. Takeda M. Takahashi and I. Nakai New Dev. Ion. Ex&. Proc. In?. Cot$ Ion Exch. 1991 151 (Chem. Ah. 1992 117 142212). G. Cao. M.E. Garcia. M. Alcala L. F. Burgess and T.E. Mallouk. J. .Am. Chem. Soc. 1992 114 7574. 82 L. A. Vermeulen and M. E. Thompson Nature 1992 358 656. Ti,Zr and Hf 115 8 Titanium Silicates and Related Systems A synthetic route has been describeds3 for incorporating up to eight titanium ions per unit cell into titanium silicate molecular sieve (TS-1); a hydrothermal method is reported for preparing a titanium silicoaluminate oxidation ~atalyst.'~ A mixed-valence lanthanum titanium oxosilicate with a quasi-2D rutile-based structure has been described.9 Organometallic Compounds with Polyhapto Ligands Intense activity in this area means that only a selection of papers can be discussed; a-bonded organometallics have already been mentioned in section 5. New routes have been des~ribed~~.~' to [Ti(arene),]" (n = 0 -1 ). The crystal structures8 of 'titanocene' shows it to be a dimeric fulvalene (7); meanwhile [Ti(C,H,),] has been stabilized as the bis(trimethy1phosphine) add~ct.~' The 15-electron tervalent titanium alkyls [TiR(C,R,),] have been studied;'" they are unwilling to form adducts undergo thermal decomposition to form fulvalene type cornplexe~,~' and and oxidize with PbCI forming Ti" corn pound^.^^ Phot~electron'~ ESR94 spectra have been reported for bis(cyclopentadieny1) titanium(w) halides.Very long metal-metal bonds have been observed for some Ti(w) and Zr(m) dimer~;~~.~~ cleavage of some of these paramagnetic Zr(r11) dimers with nucleophiles has been reported. ESR spectra have been obtained from the triplet state in some titanium(m) dimer~.'~ The catalytic and insertion reactions of the 14-electron [MMe(C,R,),] and + R3 A. Thangaraji and S. Sivasanker. J. Chrm. Soc.. Chem. Conimun. 1992. 123. 84 M. A. Camblor. A. Corma. A. Martinez. and J. Perez-Pariente J. Chem. Soc.. Chrm. Commun..1992. 589. " S. Wang and S-J. Whu J. Am. Chem. Soc.. 1992 114 6920.86 H. Bonnemann and B. Kordll Angew. Chem. Inr. Ed. Engl.. 1992. 31 1490. " D.W. Blackburn. D. Britton. and J. E. Ellis Angew. Chem. Int. Ed. Engl. 1992. 31 1495. "'S. I. Troyanov H. Antropiusova and K. Macg J. Oryanomet. Chem. 1992. 427. 49. " D. W. Stephan Oryanometallics. 1992 11 996. 90 G.A. Luinstra. J. Vogelzang and J. H. Teuben. Organometallics 1992. 11 2273. YI G.A. Luinstra and J. H. Teuben. J. Am. Chem. Soc. 1992. 114 3361. 92 G.A. Luinstra and J. H. Teuben Orgunometallics 1992 11. 1793. 93 T. Vondrak. K. Mach and V. Varga. Oryanometallics 1992 It. 2030. 94 K. Mach and J. B. Raynor J. Chem. Soc. Dalton Trans.. 1992. 683. 9s P. B. Hitchcock. M. F. Lappert G. A. Lawless H. Olivier. and E. J. Ryan J. Chem. Soc.. Chem. Commun..1992 474. M. Benard and M.-M. Rohmer. J. Am. Chem. Soc. 1992 114. 4785. 97 E. Samuel J. F. Harrod D. Gourier Y. Dromzee F. Robert and Y. Jeannin. Inorq. Chrm. 1992.31.3252. 116 S. A. Cotton 16-electron [MMeL(C,R,),] + compounds (M = Ti Zr) have been and the first base-free zirconocene hydride made. ''' ' CPMAS-NMR investigations have been made of ~atalysts''~~' where organozirconium compounds are bound to O3 silica and alumina surfaces. The unusual bimetallic complex [Cp:Hf(Cl)(p-Cl)CaCp:] has been described.' O4 Stereoselective synthesis using metallocene complexes has attracted attenti~n.'~~-'~' Phosphine and [{ ZrCpT(N,),} ,(p-N,)] give complexes that react with alkenes and PH, yielding primary alkylphosphines under very mild conditions.'08 98 M.Bochmann and S.J. Lancaster J. Organomet. Chem. 1992 434 C1. 99 A. D. Horton and A. G. Orpen Oryanometallics 1992. 11 8. I00 J. J. W.Eshuis Y. Y. Tan A. Meetsma J. H. Teuben J. Renkma and G.G. Evens. Organometallics 1992 11 362. '01 X. Yang C.L. Stern and T. J. Marks Angew. Chem. Int. Ed. Engl. 1992 31 1375. C. Sishta R. M. Hathorn and T.J.Marks J. Am. Chem. Soc. 1992 114 1112. F. Quignard C. Lecuyer C. Bougault F. Lefebre A. Choplin D.Olivier and J. M. Basset Inorg. Chem.. 1992 31 928. S. C. Sockwell P.S. Tanner and T.P. Hanusa Organometallics 1992. 11. 2634. A. L. Rheingold N. P. Robinson J. Whelan and B. Bosnich. Organometallics 1992 11 1869. J. Okuda Angew. Chem. Int. Ed. Enyl. 1992 31 47. G. Erker Pure Appl. Chem.. 1992 64 393.108 S. Nielsen-Marsh R.J. Crowte and P.G. Edwards J. Chem. Soc. Chem. Commun.. 1992 699.

ISSN:0260-1818    

DOI:10.1039/IC9928900107

出版商:RSC    

年代:1992

数据来源: RSC

摘要:

10 V Nb and Ta By H. SLOAN Consulting Chemist 40 Wendan Road Newbury Berkshire RG 14 7AF UK 1 Introduction Oxoniobates containing metal clusters,' hydrides, solid state NMR of coordination compound^,^ polyvanadates4 and their coordination and solution ~hernistry,~ and halogen exchange between main group metal compounds and vanadium (and molybdenum) compounds as a synthetic technique6 have been reviewed. Major sections on the vanadium group are also included in a review of di- tri- and polyphosphine complexes of transition metals;' niobium and tantalum compounds are referred to in a review of the protonation of coordinated dinitrogen.' Bond-stretch isomerism in niobium compounds9 has been considered (see also Chapter 11 Section 2) and a publication on the catalysis of hydrogen peroxide oxidations includes" the early transition polyoxmetalates.This report is arranged on the basis of the most significant other atom in the compounds discussed; there is a separate section on metalates. 2 Hydrides Dihydrogen reacts' ' with [Ta(OR),R;] (R = C,H,Pri-2,6 R' = CH2C,H,-4-Me) in the presence of a phosphine L to give [Ta(H),(OR),L]. The crystal structure of the dihydride (L = PMe,Ph) showed a severely distorted octahedron with the trans- hydride ligand bonds bent towards the phosphine ligand (H-Ta-H = 13.5")and a long Ta-P bond (2.650 A). NMR and IR spectroscopy support the trans-dihydride disposition. Phosphine exchange occurs readily but not rapidly on the NMR timescale; in benzene-d the hydride ligands are scrambled with deuteride over several days at room temperature.Hydrogenation of the aryl substituent of the phosphine ligand occurs over 24 hours e.y. PMe,Ph is converted to PMe,Cy. Use of the J. Kohler G. Svennson and A. Simon .4nqew. Chem.. lnt. Ed. Engl. 1992 31 1421. A. Y. Esayed and D.0.Northwood Inr. J. Hydrogen Energy 1992 17 41. ' J.A. Davies and S. Dutremez Coord. Chem. Rev. 1992 114 201. W.G.Klemperer T. A. Marquart and 0 M. Yaghi Anyew. Chem. Int. Ed. Enyl. 1992,31,49; H. Reuter. .4nqew. Chem. Int. Ed. Engl. 1992 31 1185. Q. Chen and J. Zubieta Coord. Chem. Rev. 1992 114 107. ' P. Sobota Polyhedron 1992 11 715. ' A.-M. Caminade J.-P. Majoral and R. Mathieu Chem. Rev. 1991 91 575. ' G.J. Leigh Acc. Chem. Res. 1992. 25 177. ' V.C. Gibson and M.McPartlin J. Chern. Soc. Dalton Trans. 1992 947. lo 'Metal catalysis in Hydrogen Peroxide Oxidations'. ed. G. Strukul Reidel. London 1991 Chapter 8. 'I V. M. Visciglio P. E. Fanwick and I. P. Rothwell J. Chem. Soc. Chem. Commun.. 1992 1505. 117 118 H. Sloan phosphine PMePh gave only products resulting from sequential hydrogenation of the phenyl groups with no products from partial hydrogenation of one or both rings. Free condensed aromatic hydrocarbons are also hydrogenated though free phosphine inhibits the reaction indicating dissociation to [Ta(H),(OR),] is a key step. 3 Carbonyls The compounds [MCI(CO),(dmpe),] (M = Nb Ta) are important precursors and a convenient high yield synthesis has been developed,12 involving the catalytic reduction of [MCl,(dmpe),] with Mg(anthracene) under CO.These compounds have a capped trigonal prismatic structure with an acute OC-M-CO angle; the close non-bonded C-C contact is consistent with the previously observed reductive coupling of the carbonyl ligands. 4 Nitrides and Nitrogen-donor Ligands Lithium niobium nitride Li,NbN, has' an anti-fluorite superstructure with regularly-ordered distorted Li,Nb cubes each Nb atom being tetrahedrally co-ordinated by nitrogen. Marked differences from similar Ta and V compounds suggest some doubts over the latter structures. Reduction of [VCl,(thf),] with NaBHEt, followed by addition of a cold suspension of Li(dfm) in thf gavel4 the complex [V,(dfm),] as the first structurally characterized V" complex with a triple bond between vanadium(i1) atoms.As well as the short V-V bond the V-N bonds are also short consistent with the high basicity of the dfm ligand. The methine proton has a very large chemical shift. In the presence of [PPh,CH,Ph]- C1 [VCl,(thf),] reacted' with o-phenylenediamine or its 4,Sdimethyl derivative to give the octahedral anions [VCl,(diamine)] -. The dimethyl complex is isostructural with the analogous chromium anion and evidence points to the metal-N-C angle being diagnostic of the nature of the coordinating nitrogen. The chloro groups trans to N and trans to another chloro ligand show greater differences than in the chromium analogue. In the absence of a phosphonium salt trans-[VCl,(diarnine),]Cl is obtained and with the vanadium(i1) salt [V (p-Cl),(thf )6] 2 [Zn,CI,] trans-[VCI ,(o-phenylene-diamine),] was obtained.Reaction of [VOCl,(tmu),] with vinylimidazole in CH,CI readily gave' trans-[VOCl( 1-vinylimidazole),]Cl with N-coordination of the heterocycles. X-Ray diffrac- tion studies of the air-stable compound were complicated by disorder in the 0-V-Cl moiety; the vanadium K-edge EXAFS was used to further refine the structure. Few first row nitride complexes are known as models for nitrogen fixation. In contrast to the high oxidation state of other known nitrides of vanadium the core was obtained' in [V1i'Br,(N,)(dmpe)(p-N)VivBr(dmpe),l, Viil(p-N)ViV formed by the reductive decomposition of Me,SiN in the presence of truns-[VBr,(dmpe),] 12 J. D. Protasiewicz. P. A. Bianconi I.D. Williams. S. Liu Ch. P. Rao,and S. J. Lippard. Inory. Chrm.. 1992. 31 4134. l3 D. A. Vennos and F. J. DiSalvo. Acru Cryualloyr.. Srcr. C. 1992. 48. 610. 14 F.A. Cotton L. M. Daniels and C.A. Murillo Anycw. Chem.. Int. Ed. Enyl. 1992. 31 737. '' C. Redshaw G. Wilkinson. B. Hussain-Bates and M. B. Hursthouse. J. Chrm. Sot,.. Dalton Trans. 1992. 1803. '' L. J. Calviou. J. M. Arber. D. Collison. C.D. Garner. and W. Clegp. J. Clirm. Soc .. Chrm. Comrnun. 1992 654. " D. B. Sable and W. H. Armstrong. Inory. Chrm.. 1992. 31. 161. V Nb and Ta (1). The V-N-V bonds are non-linear (165”) with very different V-N bond lengths (VI’I-N = 1.972A VIV-N= 1.652A). Notable spectral features included a 19-line EPR spectrum in thf solution at room temperature; complex (1) was obtained in situ from trans-[VBr,(tht),] and two equivalents of dmpe.The asymmetric vanadium(v)-vanadiurn(tI1) complex (2) with a nitride bridge was formed’ rapidly via various sequences (Scheme 1). The crystal structure shows a short V-N bond (1.588A) involving five-coordinate vanadium(v) typical of a triple bond with the nitrido ligand in the axial position of the square pyramid. The six-coordinate vanadium-nitrido bond is somewhat shorter (2.092 A) than those found for VII1-Namine single bonds. c1 thf--.\v= Cl/-Reagents i tmeda with lossof SiClMe,;ii [VCl,(thf),] with loss ofSiCIMe, iii tmeda. [VCl,(thf),] with loss of SiCIMe, iv tmeda [VCl,(thf),]; v tmeda. with loss of (3) Scheme 1 A series of seven-coordinate complexes [MC1(CNR)(CO)(dmpe)2] (M = Nb R = Me Cy Bu‘; M = Ta R = Me Et Bu‘) has been synthesized” by photolysis of [MCl(CO),(dmpe),] in the presence of CNR and reduction of [TaCl,(dmpe),] in the presence of CNR gave [TaCl(CNMe),(drnpe),]; all these complexes are fluxional in solution having NMR spectra consistent with capped trigonal prismatic or pentagonal bipyramidal geometry.Crystal structure determinations showed a distorted capped trigonal prism as the common structural form with significantly bent C-N-C bonds. Niobium pentachloride reacted” with Me,SiNPPh in acetonitrile to form [NbCI3(NPPh,),] which has a distorted trigonal bipyramidal structure; the two phosphorane inimato ligands and one of the chlorides are in the equatorial positions. The Nb-N and P-N bond lengths indicate double bonds and the Nb-Cl bonds are unusually long.Reaction of [Nb(NEt,),Cl,] in thf/py with two equivalents of LiNHmes gave2 the trigonal bipyramidal [NbCl(=Nmes),py,] analogous to known in K. L. Sorensen M. E. Lerchen. J. W. Ziller and N. M. Doherty. Inory. Chrm. 1992 31 2678 19 E. M. Carnahan R. L. Rardin S.G. Bott. and S. J. Lippard. Znory. Chem.. 1992 31 5193. 20 F. Weller. D. NuBhar and K. Dehnicke. Z. Anorg. Allg. Chem. 1992. 615 7. ’’ D.P. Smith. K.D. Allen M.D. Carducci. and D E. Wigley. Inorg. Chrm. 1992. 31. 1319. 120 H. Sloan tantalum compounds. Using six equivalents of LiNHmes gave the salt [Li(thf),] [Nb(=Nmes),(NHmes)] though the thf is slowly replaced by pyridine giving a product with a less labile solvate.The thf-solvated salt reacted with LiBu" giving [Li(thf),][Nb(=Nmes),Bu] where the n-butyl group in the tetrahedral anion is disordered. A study of the 14N and 15N NMR spectra of complexes of tantalum (as well as complexes of Mo W Re and 0s) has shown" little variation of chemical shift with linear and bent metal-N-R moieties for a wide range of R coordination number and other ligand type. This contrasts with other nitrogen donors such as diazenides (-N=NR) and nitrosyls. There is also a closer parallel between the nitrogen and metal shielding. Reaction of TaC1 with Me,SiNPPh gave2 [Ta(NPPh,),][TaCl,]. The cations are distorted tetrahedrons with Ta-N and N-P bond lengths indicating double bonds. There are two independent cations with differing Ta-N-P angles relating to the disposition of the phenyl substituents.The octahedral anions are symmetrical. Electron diffraction studies of [Ta(NMe,),] indicated2 a square pyramidal structure with the apical Ta-N bond (1.937 A) shorter than the basal Ta-N (2.040 A). Electron diffraction data for [V(NMe,),] and [V(OBu'),] indicatedz5 distorted structures the distortions being in the form of variations from the regular tetrahedral angle and not of bond distances. In [V(NMe,),] angles of 100.6' and 114.1' were obtained; V-N is 1.879 A. In the butoxide the angles are 106.7' and 115.1 O and the V-0 distance is 1.779 A. Reduction of [VCl,(thf),] by sodium in the presence of diphosphines and dinitrogen yielded26 trans-[V(N,),(L-L),] -.The crystal structure (for L-L = dppe) of the anion is asymmetric because of the phenyl group dispositions and very like that of the neutral molybdenum analogue but with a close interaction V-NEN . . .Na between the sodium ion and terminal nitrogen. In solution 51VNMR showed that the dmpe analogue retains the same anionic structure. Excess HBr converts one in four of the nitrogen atoms to ammonia and a small amount of hydrazine but no hydrogen is formed. 5 Oxygen-donor Ligands A simple high yield synthesis of vanadium(v) compounds [VO(O,)QL] (Q = quinolinate L = EtOH dmf dmso or thf) is provided27 by the reaction of V,O with hydrogen peroxide and a solution of quinoline in the chosen solvent at pH = 2. The salts A3[VO(02)(HP0,)]~2Hz0 (A = K or NH,) are similarly produced from V,O, H202 and phosphoric acid at pH = 6.Evidence for an q2-bonded dioxygen group is provided from spectral studies. A similar reaction with bipy or phen gave28 the seven-coordinate complexes [VO(Oz)(L-L)z][CIO,] (L-L = bipy or phen). An X-ray 22 D. C. Bradley S. R. Hodge J. D. Runnacles M. Hughes. J. Mason,and R. L. Richards. J. Chem.Soc. Dalton Trans. 1992 1663. 23 D. NuBhar F. Weller A. Neuhaus G. Frenking and K. Dehnicke Z. Anorg. Ally. Chem. 1992 615 86. 24 K. Hagen C.J. Holwill D. A. Rice. and J. D. Runnacles Inorg. Chrm. 1992. 31 4733. 25 A. Haaland K. Rypdal H.V. Volden and R. A. Andersen J. Chrm. Sot.. Dalton Trans. 1992 891. 26 D. Rehder. C. Woitha W. Priebsch and H. Gailus J. Chem. Soc. Chrm. Commun.. 1992. 364. 27 M.Bhattacharjee M. K. Chaudhuri and P. C. Paul Can. J. Chem. 1992 70 2245. 28 V. S. Sergienko V. K. Borzunov and M. A. Porai-Koshits Russ. J. Inorg. Chem. (Engl. Transl.),1992.37. 534 (1062). V Nb and Ta structural determination showed the 0x0 ligand and one of the nitrogen atoms in the axial positions of a pentagonal bipyramid around vanadium; the v2-dioxygen group is almost symmetrically bound to vanadium and lies in the equatorial plane. The V-N bond opposite the dioxygen is significantly longer (bipy 2.247; phen 2.24 A) than other equatorial V-N bonds (bipy 2.126,2.136; phen 2.12,2.13 A) and are similar to the axial V-N bonds (bipy 2.243; phen 2.24A) which are trans to the 0x0 ligand. Reaction of VOCI with bulky biphenolic ligands (4) gave29 monomeric tetrahedral [VOCl(biphenate)] with a labile chloride.R (4) R = H R' = Me; R = Me R' = But (6) The complex [V(acac)Cl,(thf ),I (5)was prepared,' from [VO(acac),] by reaction with [TiCl,(thf),] or from [VCl,(thf),] and Hacac. Reduction of (5) with zinc in thf gave (6) the crystal structure of which showed meridional disposition of the thf ligands and bridging between vanadium and zinc by chlorine and by an oxygen from the acac ligand. There are few simple non-oxo vanadium(1v) or vanadium(v) species. [VO(acac),] in CH,Cl reacted,' with phen and dtbc to give [V'v(dtbc),(phen)]CH2C12 which was oxidized with AgSbF to [VV(dtbc),(phen)][SbF,]CH,C1,. The removal of the 0x0 group by dtbc is of particular interest. X-Ray diffraction showed very little difference between V-0 and V-N bond lengths or between the bite angles of the ligands of the two compounds.However other coordination angles change significantly and the vanadium(1v) compound has a marked distortion towards the trigonal prismatic form contrasting with the slightly distorted octahedral geometry of the vanadium(v) compound. The bipy analogue [V'v(dtbc),(bpy)]CH,CI was ,similarly prepared3 and has an analogous structure. For all three compounds the most sterically demanding isomer with the 3,St-butyl groups syn is observed. The equilibrium in Equation 1 shows an expected variation with concentration but the exchange is sufficiently slow at room temperature to allow the two species to be detected3 by NMR spectroscopy. The dimer shows short V-Oalkoxy bonds with vanadium in near trigonal pyramidal coordination.n[VO(OR)J [{VO(OR),),] (R = cyclopentyl) (1 1 The unusual all-oxygen donor dimeric vanadium(v) complex (7) has 34 the 0x0 ligands in the axial positions of trigonal bipyramidal disposition around each 29 P. J. Toscano E. J. Schemerhorn C. Dertelbacher D. Macherone and J. Zubieta J. Chem. SOL'.,Chem. Commun. 1991 933. 30 E. Solari S. De Angelis C. Floriani A. Chiesi-Villa and C. Guastini. Inory. Chem. 1992 31 141. 31 T. A. Kabanes A. J. P. White D.J. Williams and J. D. Woollins J. Chem. Soc. Chem. Commun. 1992 17. 32 T. A. Kabanos A. M. Z. Slawin. D.J. Williams and J. D. Woollins J. Chem.Soc.,Dalron Trans. 1992 1423. 33 F. Hillerns F. Olbrich U. Behrens and D. Rehder.Anyew. Chem. Int. Ed. Engl. 1992 31 447. 34 T. W. Hambley R.J. Judd and P. A. Lay Inory Chem.. 1992 31 343. 122 H. Sloan Et Et (7) vanadium atom. The V=O double bonds are long compared with those of other alkanoate complexes. NMR spectroscopy showed that the plane of symmetry is retained in solution with limited rotation about the C-C bond of the methylene to alkanoate link. The stability of this complex probably results from the ethyl groups providing steric protection of the metal site. In attempting to form monomeric vanadium(Ir1) chelated complexes of dppb in an inert atmosphere binuclear [(VOCl,(thf)),(dppb)] was formed;35 the oxygen prob- ably comes from adventitious air or water in the Celite filter. Each vanadium(1v) is trigonal bipyramidal with oxygen and two chlorine atoms in the equatorial plane.The EPR spectrum shows one unpaired electron on each vanadium atom with no hyperfine splitting from ,lP. The four-coordinate complexes [NbO(O-2,6-R2C,H,),] (R = Me But) were ~ynthesized~~ by the reaction of [NbOCI,(NCMe),] and Li0-2,6-R2C6H3. The Nb-0 bond lengths and Nb-0-C angles37 in tetrahedral [NbO(OC6H,Ph2-2,6),] are typical of mono-oxo niobium compounds even though these often take distorted octahedral form. The complex [TaCI(OC,H,Bu'-4),] was synthesized from TaCI and the free phenol in refluxing benzene. It forms 1 1 adducts with aliphatic amines and the salts [Ta(OC,H,Bu'-4),][MC14] with MCI (M = Al Fe Sb). 6 Other Chalcogen-donor Ligands Addition of two equivalents of Na(pyt) to [VOCl,(thf),] in thf gave 38 [V,O,(pyt),] where each vanadium atom is octahedral with a terminal 0x0 group one pyt as a simple chelate and two pyt groups with the sulfur bridging to the other vanadium atom Reaction of Na(pyt) with [VCl,(thf),] in thf gave [Na(thf),V(pyt),] a rare example of seven-coordinate vanadium(rI1).In the crystal vanadium is bound by three chelated pyt ligands and a fourth by sulfur only; the nitrogen of this fourth pyt ligand and three sulfur atoms bridge to the sodium the coordination sphere of which is completed by thf ligands. Na(pyt) reacted with [VCl,(tmeda),] to give the unusual thiolatovanadium(i1) complex [V(pyt),(tmeda)] and with VC12-4MeOH in acetonit-rile to give39 the [V(pyt),]- anion. Under similar conditions the use of sodium aniline-2-thiolate gave the oxidation product [V(NH2C,H,S-2),(NHC,H,S-2)] - with loss of hydrogen from one ligand.The neutral complex [V(quinoIine-8-thiolate),] was similarly formed. 35 A.K. Fazlur-Rahman V.G. Young Jr and J.G. Verkade Inorg. Chem. 1992. 31 2285. 36 T. P. Kee and V.C. Gibson Polyhedron 1992. 11 587. 37 J.S. Yu P.E. Fanwick and 1. P. Rothwell Actu Crystullogr. Sect. C 1992 48 1759. 38 J. G. Reynolds. S.C. Sendlinger. A.M. Murray J.C. Huffman and G. Christou. Angew. Chem. Inr. Ed. Engl. 1992 31. 1253. 39 G. Henkel B. Krebs and W. Schmidt Angew. Chem. Int. Ed. Engl. 1992 31. 1366. V Nb and Ta 123 A novel niobium-sulfur cluster stabilizes the tetrathioborato ligand in diamagnetic complex (8),formed4' by the reaction of [Nb,Cp,f (p-B2H6),] (Cp,' = (q-C,Me,Et),) with sulfur in decane at 170°C.The Nb-S bonds are similar to those in other non-bridging situations. The Nb-S(Nb) bond lengths are shorter than in other cyclopentadienylsulfidoniobium complexes. The Nb-Nb distances are consistent with partial single bonds. The reaction of NbOI with niobium iodine and tellurium at high temperature gave41 the cluster cation (9). The starred(*) atoms in the structure of (9)nearly define a plane of symmetry -the oxygen atom is just off this plane in the otherwise symmetric molecule. The four Te atoms form a square plane. HS I--. I' The reaction of NbCI with NaSBu' in MeCN gave4 the complex anions [Nb(S),(SBu'),]-(10)and [Nb(S)(SBu'),]- (1l) containing Nb=S units formed by cleavage of a C-S bond.The tetrahedral (10)was also formed by oxidation of (1 1) with sulfur. Complex (11) is distorted trigonal bipyramidal apparently showing a strong trans influence due to the axial sulfide ligand; the axial Nb-SBu' bond length is longer 2.567,& than the equatorial average of 2.38,&. The reaction of NaS,CNEt with [M,Cl,(tht),] (M = Nb Ta) gave43 [MS(SCNEt,)(S,CNEt,),].;C6H6 which has a pentagonal bipyramidal structure; the terminal sulfide and a sulfur from one of the dithiocarbamate ligands occupy the axial positions. The thiocarbamyl ligand is bound through both S and C. A new synthesis of [MS4I3- (M = Nb Ta) previously only known in intractable solids has enabled44 a structural study to be made.Reaction of [M(OEt),] S(SiMe,) and LiOMe (1 :4 3) in MeCN gave Li3[MS,]-4MeCN which gave the stable pure compound Li,[MS4].2tmeda on recrystallization in the presence of tmeda. The vanadium compound was prepared similarly from [VO(OMe),]. All three com- pounds are isomorphous and have tetrahedral anions with M-S bond lengths longer than those generally found in terminally bound sulfides. The differences in colour (V dark red; Nb light yellow; Ta colourless) arise from a progressive high energy shift of the first ligand-to-metal charge-transfer band. 40 H. Brunner G. Gehart. B. Nuber J. Wachter and M. L. Ziegler Angew. Chem. Int. Ed. Engl.. 1992. 31 1021. 41 W. Tremel J. Chrm. SOC.,Chem. Commun 1992. 126. 42 D. Coucouvanis S. Al-Ahmad C.G.Kim. and S.-M. Koo Inorg. Chem.. 1992 31 2996. 43 P. F. Gilletti D.A. Femec. F. I. Keen and T. M. Brown Inorg. Chem. 1992 31 4008. 44 S.C. Lee J. Li J.C. Mitchell and R. H. Holm Inorg. Chem.. 1992 31 4333. 124 H. Sloan A mixture of [NH,][VS,] CuCl Na[S,CN(CH,CH,),O] (Nadtc' ) and NaSPh in dmf gave4 the distorted cubane-type anion [V,CU,S,(~~C'),(SP~),]~ ~ where each vanadium atom has a distorted square pyramidal coordination sphere comprising the two sulfur atoms of a dtc' anion and three sulfur atoms of the (V,Cu,S,) cubane core. A vanadium-silver analogue was obtained similarly. Relatively shorter bonding to the external ligands at both vanadium and copper support the presence of charge transfer from copper(]) to vanadium(1v).7 Halide Ligands The electronic and EPR spectra of VF have shown4 the presence of two short axial V-F bonds with longer bridging equatorial V-F-V bonds. The anion of [PMePh,]- [TaF,] has 47 a regular octahedral structure with a Ta-F bond length of 1.84(6)A. The anions in Na[MCI,] (M = Nb Ta) have48 a significant off-centre displacement of the metal atom within the octahedral C1 coordination sphere. The overall structure is similar to that in K,[PtCI,] with half the cation sites vacant; the off-centre displacement relates to the cation location in alternate channels along [OOl]. The isomorphic 1,2,3-tris(dirnethylamino)cyclopropenium hexachlorometalates [C,(NMe,),][MCI,] (M = Nb Ta) are known to exhibit strong outersphere charge transfer interactions.Each salt contains4' two crystallographically different anions in one of which three chlorine atoms have close contacts with the three nitrogens of the cation. This may be the reason for the colour and stability of these compounds compared with those of the individual colourless ions. The methanol solvated clusters in [Ta,C1 2(MeOH),]Br3 and [Ta,CI ,(MeOH),]-Br3.4H,O have5' an octahedral arrangement of tantalum atoms with a chloride bridge associated with every Ta-Ta bond; each Ta has one terminally bound methanol ligand. Similar cluster ions with chloride or phosphine terminal ligands are known; shorter Ta-Ta bonds are found with the terminal oxygen donor. 8 Metalates Niobic acid formed by in situ hydrolysis of aqueous K,Nb04 or K8Nb6Ol9 catalyses' the photochemical decomposition of MeOH to give hydrogen.Calcining the acid at up to 380 K increases the catalytic activity. Orthorhombic NbPO, grown at high temperature (1375 K) in a K-Nb-P-0 system of composition KNb 2P6033 has a framework built5 from corner-sharing NbO octahedra and PO tetrahedra. There is no suggestion of oxygen deficiency in this product. Preparation by chemical vapour transport at 1000"-900 "C using I or NH,Cl as the transport agent gave53 known phases; the orthorhombic phase required reducing conditions by the addition of NbP. However this preparation gave NbPO -b a blue orthorhombic form deficient in 45 Y. Yang Q. Liu L. Huang B. Kang and J. Lu J. Chem. Soc.. Chem. Commun. 1992 1512. 46 H. Stratemeier M.A. Hitchman R. J. Deeth and R.Hoppe J. Chem. Soc. Dalton Trans. 1992 3419. 47 M.A. McLoughlin. N. 1,. Keder and W.C. Kaska. Acta Crystalloyr. Sect. C 1992 48 1098. 48 H. Henke Z. Kristallogr. 1992 198 1. 49 H.N. Schafer H. Burzlaff A.M. H. Grimmeiss. and R. Weiss Acta Crystalloyr. Sect. C 1992 48 795. 50 N. Brnicevic D. Nothig-Hus B. Kojic-Prodic Z. Ruzic-Toros 2.Danilovic and R. E. McCarley Inorg. Chem. 1992 31 3924. 51 A. Kudo A. Tanaka K. Domen K. Maruya and T. Onishi Bull. Chem. SOC.Jpn. 1992,65 1202. 52 D. L. Serra and S.-J. Hwu. Acta Crystallop. Sect. C. 1992 48 733. 53 U. Kaiser G. Schmidt R. Glaum and R. Gruehn Z. Anorg. Allg. Chem. 1992. 607,113. V Nh and Ta oxygen with a similar structure to the colourless form observed at >340 "C. Heating the oxygen-deficient phase to 340 "C gave a reversible transformation between monoclinic and orthorhombic phases.Identification of the localized or delocalized nature of vanadium centres in polyoxovanadates has been shown54 to be possible using valence bond summation. The M,O, core is a common structural type in polyoxometalate chemistry. The V,O core can remain intact while undergoing55 considerable distortion on reduction or protonation. The simplicity of the hydrothermal technique has led to its frequent use for the production of polyoxometalates. Two equivalents of [NH,][VO,] with one equivalent of EtC(CH,OH), in water at 200°C for four days gave56 crystals of [NH4]4[V,,0,6(EtC(CH,0),)4]~4H20 (12). The structure consists of a reduced (Reproduced from J.Chem. SOC.,Chem Commun. 1992 305) {Vlo028) core where ten doubly bridging and two triply bridging 0x0 groups are replaced by the twelve alkoxy donors from the four ligands. Of the six potential triangular ligand sites four are symmetrically occupied. Refluxing [NBu,],- [H,V,,O,,] in MeCN for several hours under nitrogen gave57 the tridecavanadate [NBu,],[V,,O~~] with an anion built from VO octahedra in contrast to the VO square pyramids previously known. This isopolyvanadate has the lowest charge density of any known polyvanadate. Reactions of [NBu,],[H,V,,O,,] with RC(CH,OH) yield5 hexavanadate clusters in the anion [V,O 3{(OCH2)3CR),]2 -[R = Me NO, NHC(O)CHCH,]. These vanadium(v) clusters are readily reduced by organohydrazines to the mixed-valence species [VTVYO ,(OH),{ (OCH,),- CNO,),]* -and the completely reduced [V',"O,(OH),{ (OCH2),CMe),l2- anions.While the common hexametalate core (M,O,,) is present this is distorted by substituting doubly bridging 0x0 groups by the alkoxy donor oxygen atoms and by the presence of reduced sites. 54 A.-L. Barra D. Gatteschi B. S. Tsukerblatt. J. Doring A. Muller,and L.-C. Brunel lnorg. Chem. 1992,31 5132. 55 Q. Chen D. P. Goshorn C. P. Scholes X. L. Tan and J. Zubieta J. Am. Chem. Sot.. 1992 114 4667. 56 M.I. Khan Q. Chen and J. Zubieta J. Chem. SOC. Chem. Commun. 1992 305. 57 D. Hou K.S. Hagen and C.L. Hill J. Am. Chem. Sot. 1992 114 5864. '' Q. Chen and J. Zubieta lnorg. Chim. Actu 1992 198-200 95. 126 H. SIoan Diammonium hydrogen phosphate reacted59 with [NH,],Na,K,[V 100,s] to give after addition of [NHMe,]CI [NHMe,],[NH,][H,PV,,O,,] which has an 2-Keggin type framework capped by two VO units.The protonated sites are at doubly bridging oxygen atoms. Reaction of ammonium metavanadate with phenylphosphonic acid and hydrazine hydrate in the presence of dimethylammonium chloride gave,’ the host/guest compound [NH,Me2][2NH,+ ,2C1-] c [V,,O,z(OH),(H,O),(PhPO,),l .5H20-4Me2NCH.The anion is a ring of two { V,O,} (one localized Vv) units and + two {V202(0H),(H20)(PhP03),)6-(two V”) units. The two aqua ligands partition the cavity within the anion. The reaction of NaVO, As,O, KSCN and sodium rhodizonate in water at pH 4.4 gave6’ K,N~[As,V~V~O,~H,].~H,O. The structure consists of an E-Keggin core with three VO vertices removed and capped by three VO and three AsOH units.The open ‘pole’ of the anion is capped by a potassium cation. Magnetic susceptibility studies gave an effective magnetic moment of 3.59 pB,corresponding to 1.69 pB per vanadium(1v) centre so all five vanadium(1v) centres are practically uncoupled. The analysis of the magnetic susceptibility data and EPR spectra of the vanadium(1v) ions [V 5AS6042(H,0)]6 -and [V,,As80,,(S0,)]6 - and extended Huckel calculations thereon has provided62 a detailed understanding of the preferred spin arrangement and energies of the spin levels; qualitative considerations of exchange pathways are still needed to reduce the number of independent parameters. The anion of [NBu,] [NH,] 2[V lo0,,(0,AsC6H,-4-NH,)3] consists63 of a VO group encapsulated by a [V,02 (O,ASC,H,-~-NH,),]~-toroid; the latter has three (V,O ,} moieties linked by bridging 0x0 and arsenato ligands.The central octahedral VO unit has vanadium displaced toward one face of the octahedron. There are thus four different 0x0 groups within the ion. An unusual twisted 24-membered ring { V&6012} with intraring 0x0 bridges occurs in [~~u,],[~,{~,~,,(~,~sC,H,),)I~~~,~. s9 M.I. Khan J. Zubieta and P. Toscano Inorg. Chim. Acta 1992 193. 17. A. Miiller K. Hovemeier and R. Rohlfing Angew. Chem. Inr. Ed. Enyl.. 1992 31 1192. 61 M.I. Khan Q. Chen J. Zubieta. D. Goshorn and R.C. Haushalter Inorg. Chim. Acfa 1992 191 97. 62 A.-L. Barra D. Gatteschi L. Pardi A. Miiller and J.Doring J. Am. Chem. Soc.. 1992 114. 8509. 63 M.I. Khan Y.Chang Q. Chen. H.Hope S.Parking D. P. Goshorn and .I.Zubieta. Angew. Chem..Int. Ed. Engl.. 1992. 31. 1197.

ISSN:0260-1818    

DOI:10.1039/IC9928900117

出版商:RSC    

年代:1992

数据来源: RSC