ISSN:0260-1818    

DOI:10.1039/IC97976FX001

出版商:RSC    

年代:1979

数据来源: RSC

ISSN:0260-1818    

DOI:10.1039/IC97976BX003

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

The Typical Elements Part 11 Group I11 By A. G.Massey 1 Boron Professor H. C. Brown is to be congratulated on sharing this year's Nobel chemistry prize for his outstanding work on hydroboration. Small quantities ca. 10-2-10-5% of lithium beryllium and boron in uranium assemblies significantly contribute to an increase in neutron flux due to (a,n) reactions. This additional neutron flux can account for induced fission of 235Ufrom which it is concluded that the presence of low-2 elements explains the observed high ratios of neutron-induced fission of 235U to the spontaneous fission of 238Uin several uranium minerals and ores. Hydrogen reduction of boron tribromide on tantalum filaments at 1200 "C gives the so-called P-tetragonal boron modification.Analysis shows that this is a true modification in contrast to a-tetragonal phases which require small amounts of foreign atoms to stabilize their boron framework. Basically the structure consists of the same three-dimensional boron skeleton built up of simple and twinned icosa- hedra as that of a-AIBIZ but the defective twinned icosahedral B19 units in a-A1Bl2 are now completed (B21 units). A number of interstitial sites located at positions different from those occupied by aluminium are totally or partially filled by boron atoms and very probably increase the stability of the boron framework.2 By using a glow discharge the temperature required to form high-quality boron films from the hydrogen reduction of boron trichloride can be reduced and the rate of production increased .3 A differential thermaI analysis study has shown that the reaction of boron with Dy203 to give dysprosium hexaboride DyB6 occurs in five stages (i) at 820°C 54 L.B. McCusker and K. Seff J. Amer. Chem. SOC., 1979,101 5235. 55 L. Rosch and W. Erb Chem. Ber. 1979,112,394. ' M. Attrep W. B. Ledbetter and D. K. Riddle J. Inorg. Nuclear Chem. 1979,41 1. M. Vlasse R. Naslain J. S. Kasper and K. Ploog J. Solid State Chem. 1979,28 289. G. N. Kartmazov A. P. Patokin V. V. Sagalovich and V. L. Khrebtov Izvest. Akad. Nauk S.S.S.R. neorg. Muter. 1979 15 239. 14 F.A. Hart A. G. Massey P. G.Harrison and J. H. Holloway DyB03 and DyB are formed; (ii) at 1080 "C DyB4 reacts with B to give DyB,; (iii) at 1360"CDyB6 reacts with additional B giving DyB,,; (iv) at 1620 "C DyBO melts; (v) finally at 1760 "C DyBlz decomposes to DyB6 and the DyB03 produced in (i) reacts with B to form DyB6 and B203.4 The only stoicheiometric carbide sofar observed in the rhombohedra1 phase of the B-C system is B13C2.Its crystal structure is based on cubic close-packing of B12 icosahedra the inter-icosahedral spaces being occupied by two carbon atoms and a boron atom in a linear C-B-C system; thus the formula is actually B12CBC. The B12 unit is somewhat distorted from ideal icosahedral symmetry and there are four distinguishable intra-icosahedral B-B distances ranging from 1.773 to 1.823 A; the inter-icosahedral distance is significantly shorter 1.73 1A. Both carbon atoms are four-fold co-ordinated by three borons belonging to symmetry-related icosahedra and the boron atom of the CBC chain but the resulting B,C configuration is considerably distorted from tetrahedral symmetry.' The spontaneous crystallization of cubic boron nitride has been studied at 3-7 GPa and 1000-2500°C in systems containing hydrogen such as LiH-BN LiNH2-BN NaH-BN and CaH2-BN; crystal size ranged from 300 to 700 pm.6 The interconversion has been accomplished at lower temperatures (800-1000 "C) in the presence of water urea and boric acid which act as catalysts by converting some of the hexagonal boron nitride into an ammonium borate flux.At pressures below 4.2 GPa in this temperature range cubic BN reverts to the hexagonal form.' The Proceedings of 6th International Symposium on boron and borides held in 1978 at Varna Bulgaria have been published in the Journal of the Less-Common Metals 1979,67 pp.1-285. Boranes and their Derivatives.-The low-resolution mass spectra of nine common boranes have been recorded with ion-source temperatures in the range 50-60 "C to minimize thermal cracking and the results used to study thermolysis of both the pure boranes' and their mixtures with B~H~o.~ The efficiency of the laser-induced conversion of diborane into B5H9 B5Hl1 B10H14 and (BH) can be increased by sensitization with sulphur hexafluoride; yields of decaborane as high as 23% of the B2H6 consumed can be achieved. lo*ll Diborane impurities in silane can be selec- tively destroyed by i.r. laser-induced dielectric breakdown or external heating.' The gas-phase mercury-sensitized photolysis of diborane using radiation of wavelength 2537 A produces tetraborane in high yield; photolysis of pentaborane(9) under the same conditions yields the three known products 1,l'- 2,2'- and l,2'-(B5H8),; 11 B-"B coupling between the boron atoms involved in the intercage bond has been observed in the n.m.r.spectrum of the latter borane.13 E. M. Dudnik Y. B. Paderno N. Y. Shitsevalova I. E. Kir'yakova Y. A. Kocherzhinskii and E. A. Shishkin Izvest. Akad. Nauk S.S.S.R.neorg. Mater. 1979 15,627. A.Kirfel A.Gupta and G. Will Aeta Czyst. 1979 B35 1052 2291. L.F.Vereshchagin I. S. Gladkaya G. A. Dubitskii and V. N. Slesarev Izuest. Akad. Nauk S.S.S.R. neorg. Muter. 1979 15 256. T. Kobayashi J. Chem.Phys. 1979,70,5898. T. C.Gibb N. N. Greenwood T. R. Spalding and D. Taylorson J.C.S. Dalton 1979 1392. T. C.Gibb N. N. Greenwood T. R. Spalding and D. Taylorson J.C.S. Dalton 1979 1398. lo C. Riley R. Shatas and L. Opp Inorg. Chem. 1978,18,460. C. Riley and R. Shatas J. Phys. Chem. 1979,83 1679. 12 S. M.Freund and W. C. Danen Znorg. Nuclear Chem. Letters 1979 15,45. l3 J. S. Piotkin R. J. Astheimer and L. G. Sneddon J. Amer. Chem. Soc. 1979,101,4155;J.C.S. Chem. Comm. 1979 1108. The Typical Elements 15 1-Methyldiborane can be made in 20% yield by the methylation of diborane with methyl-lithium. l4 The q -cyclopentadienylphosphines CpPF and Cp2PF and their mono-methyl derivatives form normal but thermally unstable BH complexes on treatment with diborane.Above 0°C the complexes iapidly dissociate and de- compose via a complex mechanism which appears to involve reduction of the C5H rings." The i.r. and Raman spectra of several simple phosphine complexes of BH3 have been recorded and discussed.16 Vibrational spectra of several isotopic species of borane carbonyl BH3C0 in neon matrices at 10K have been observed and most of the fundamental frequencies assigned. It was concluded that the C-0 bond in BH,CO is slightly stronger than that of free carbon m~noxide.'~" A study of the acid-catalysed hydrolysis of BH3NH3 has been made.17' The bidentate ligands 1,8-bis(dimethyl-amino)naphthalene and tetramethyl-o-phenylenediamine cleave diborane asym- metrically giving [(N-N)BH,]+[BH,]-; an excess of diborane produces [(N-N)BHJ[ B2H,]-.It appears that the same wide variety of derivatives known for the trimethylsilyl group can be made using the isoelectronic H3BPMe2 e.g. Scheme 1. NaOMe Me2PCl I"\ /Me2F Me,PCl+ H3B.~F -Me,P PMe, I I BH3 BH3 NaNHz BH3 YO Me2PNH2 I BH3 Scheme 1 However in some cases the products can be even more exotic than is possible with trimethylsilyl (Scheme 2). Independent ions occur in crystals of this lithium salt; in H C Li(TMJZDA) R 4-3 /T+BH,.THF +Me2P '?Me2 -[Li(TMEDA),]+ Me2P ' -* PMe Me,P PMe It II BH3 BH3 BH3 BH Scheme 2 the anion both phosphorus atoms are tetrahedrally co-ordinated and the bond lengths in the PCP bridge are equal (1.696 A; angle PCP 128"). These bridge P-C bonds are distinctly shorter than the terminal P-C bonds (average 1.8 18 A) thus proving the ylidic nature of the bridge.I7' R.K. Bunting F. M. Junglleisch C. L.Hall and S. G. Shore Znorg. Synth. 1979,19,237. '' R. T. Paine R. W. Light and D. E. Maier Inorg. Chem. 1979 18 368. K. Hassler and F. Hofler 2.anorg. Chem. 1979,448 161. l7 (a) L. H. Jones R. C. Taylor and R. T. Paine J. Chern.Phys. 1979,70,749; (b) H. C. Kelly and V. B. Marriott Znorg. Chem. 1979,18,2875;(c) T. Onak H. Rosendo G. Siwapinyoyos R. Kubo and L. Liauw Znorg. Chem. 1979,18,2943; P. C.Keller and J. V. Rund ibid.,p. 3197; (d) H. Schmidbaur and E. Weiss Angew. Chem. Internat. Edn. 1979 18,781; (e)H. Schmidbaur E. Weiss and B. Zimmer- Gasser ibid. 1979 18 782. 16 F. A.Hart A. G. Massey P. G. Harrison and J. H. Holloway The trimethylamine adduct of isocyanoborane Me3NBH2(NC) may be prepared by first treating trimethylamine-borane with iodine to obtain Me,NBH,I; this is then treated with silver cyanide in dichloromethane and the excess silver ion removed with hydrogen sulphide.'8" Iron complexes containing isocyanoboryl ligands result from the reactions18' +IBH2* NMe -* [C5HSFe(C0),CNBH2NMe3J+I-[C5HSFe(C0)2CN] [C5H5Fe(C0),CN]+ B2H6+ [CSH5Fe(C0)2CNBH3] A number of cyanoborane-amine adducts have been prepared from the cor- responding amine hydrochlorides and NaBH,CN; alkylation of these adducts to the N-ethylnitrilium salts using OEt,BF, followed by hydrolysis gave amine-BH,C02H complexes.19n Both bis(trimethylsily1)amino-and t-butyl(trimethy1- sily1)amino-borane R(Me,Si)NBH (R = Me3Si or Bu') are monomeric at room temperature.19' Equations have been derived to calculate atomization enthalpies from bond- length-based bond enthalpies.The results were in good agreement with experimen- tal values for B4H10 B5H9 B5Hl1 B6H10 and B10H14 thus enabling reasonable predictions to be made for BH3 B8H12 B9HI5 B13H19 and B18H22.20 Also many- body perturbation theory has been used to calculate accurate binding energies for B2H6 BH3C0 and H3NBH3.,l Some selectivity in the coupling of two pentaborane(9) units is now possible. The Friedel-Crafts reaction of 2-bromopentaborane(9) and B,H in the presence of aluminium and aluminium trichloride gives l,2'-(BsH8)2 in 20% yield whereas the 2,2'-isomer results in 35% yield from the addition of KBSH8 to 2-BrBsH8.22 Mercury-sensitized photolysis of 1-MeB5H8 gives 2,2'-(1-MeB5H7),.I3 The first 1:l amine adducts of B4H8 have been isolated by treating pentaborane(11) with either hexamethylenetetramine (HMTA) or an excess of trimethylamine.23,24 A better method for preparing Me,NB,H utilizes the reaction sequence -80°C NMe, BsH1 + 2R2S -R2SBH3+ R2SB4H8-Me3NB4H8+ R2S A bis-adduct (Me3N),B,H8 forms reversibly below -40 "C. The 1:1 amine complexes can be converted into B3H7 derivatives or B5H11 by treatment with suitable reagents Me3NB,H7+H2BXOEt2 (X = C1or Br) E/ Me3NB4H8+HX(anhyd.) CHdMe,NB3H,X+ B2H6 (HMTA)B,HS +B2H6 + B5H11 (a) J. L. Vidal and G. E. Ryschkewitsch Znorg.Synth. 1979,19,233; (b) G. E. Ryschkewitsch and M. A. Mathur J. Inorg. Nuclear Chem. 1979,41 1563. l9 (a) B. F. Spielvogel F. Harchelroad and P. Wisian-Neilson J. Inorg. Nuclear Chem. 1979,41 1223; (6) P. Wisian-Neilson and D. R. Martin J. Inorg. Nuclear Chem. 1979 41 1545. 2o C. E. Housecroft and K. Wade Znorg. Nuclear Chem. Letters 1979,15 339. L. T. Redmon G. D. Purvis and R. J. Bartlett J. Amer. Chem. SOC.,1979 101 2856. 22 D. F. Gaines M. W. Jorganson and M. A. Kulzick J.C.S. Chem. Comm. 1979,380. 23 H. Kondo and G. Kodama Zriorg. Chem. 1979,18,1460. 24 A. R. Dodds and G. Kodarna Inorg. Chem. 1979,18 1465. The TypicalElements 17 The commercially available pentaborane(9) can now be converted reasonably easily into the rather rare hexaborane( KH B2H6 B5H,+Br2 + 1-BrB5H8 -K[1-BrB5H7] -B6H10 A microwave investigation of gaseous hexaborane( 10) shows that the two directly bonded basal borons are 1.6514 A apart about the distance expected for a pure single bond.z6 A remarkable series of reactions using ammonia as the cleavage reagent has demonstrated the selective degradation of the B6 borane cluster B,H6in LHCI 1-MeB5Hs+KH + Hz+K[1-MeB5H,] -1l0.c'3-MeB6HI1(80-90%) LHCI 3-MeB6Hll +NH3 -+ [H2B(NH3)J[3-MeB5H9] -3-MeB5HIo 1.HCI 3-MeB5Hlo+ NH3 -+ [HzB(NH3)z][MeB4H8] -1-MeB4H9 In each case the boron atom farthest from the methyl group is the one split off the framework; the presence of the methyls appears to stabilize the B4 Bs and B6 species relative to the parent borane~.'~ Considerable success has been achieved in coupling together two decaborane( 14) cages to give isomers of B2oHz6.A total of 15 isomers is theoretically possiblez8 and as many as eight can be detected among the products arising from the y-irradiation of BI0Hl4; the most abundant was 1,s'-bidecaboran( 14)yl which constituted 70% of the total material. The two-centre bond joining the two &OH13 cages was 1.698 A long.29 Photolysis of decaborane( 14) gives 2,2'-bidecaboran( 14)y130 whereas ther- molysis in toluene at 110"C using tetrahydrothiophen as a catalyst produces 6,6'-bidecaboran( 14)~l.~' The two major products from the reaction of BloH13MgI with 6-ClBl0H, are probably the 5,6'- and 6,6'-is0mers.~~ Decaborane( 14) and 6-C1B,,Hl3 react with [Ir(dppe),Cl] where dppe is 1,2- bis(dip henylp hosp hino)e thane to give the oxidative -addition products [IrCl(dppe)2H][BloH12X](X = H or Cl).Iridium-BIOHl3 complexes can also be made by the reaction A small quantity of by-product [Ir"'(dppe)zHz][B9H14] is formed via the cage- degradation process 32 [Bl0Hl3]-+ 3MeOH -+ [B9HI4]- +[2H]+B(OMe) 2s R. J. Remmel D. H. Johnson V. T. Brice and S. G. Shore Znorg. Synfh. 1979,19,247. 26 D. Schwoch B. Don A. B. Burg and R. A. Beaudet J. Phys. Chem. 1979,83 1465. 27 I. S. Jaworiwsky J. R. Long L. Barton and S. G. Shore Znorg. Chem 1979,18,56. N. N. Greenwood J. D. Kennedy T. R. Spalding and D. Taylorson J.C.S. Dalton 1979 840. 29 G. M. Brown J. W. Pinson and L. L. Ingram Znorg. Gem. 1979 18 1951. 30 N.N. Greenwood J. D. Kennedy and W. S. McDonald J.C.S. Chem. Comm. 1979 17. 31 S. K. Boocock N. N. Greenwood J. D. Kennedy and D. Taylorson J.C.S. Chem. Comm. 1979 16. " N. N. Greenwood W. S. McDonald D. Reed and J. Staves J.C.S. Dalton 1979 1339. I? A. Hart A. G. Massey P. G.Harrison and J. H. Holloway When decaborane( 14) is treated with aqueous potassium bisulphite an anionic intermediate is formed which reacts with concentrated sulphuric acid to give 6-SB9Hll and with dilute hydrochloric acid to give the arachno-thiaborane 4-SBSH12.33n Sulphur and decaborane( 14) when heated together in the presence of AlC13 give a mixture of 1-HSBloH13 and 2-HSBloH13.33b Metalloboranes.-Diborane reacts with K[C,H,Fe(CO),] in dimethyl ether at -78 "C to give [C,H,Fe(CO),(q'-B,Hs)] in which the C,H,Fe(CO) fragment has replaced one of the bridge hydrogen A volatile di-iron analogue of pentaborane(9) [B3H,Fe,(C0)6] is formed in low yield when B5H9,[Fe(C0),] and LiAlH4 are heated in 1,2-dimethoxyethane.One Fe(CO) group is at the apex and the other at a basal position being joined to its neighbouring boron atoms by Fe-H-B bridges (1). The iron-iron distance 2.559 A is in the range expected for Fe-Fe single (1) (Reproduced by permission from J. Amer. Chem. SOC.,1979,101,4390) Pentaborane(9) and pentacarbonylmanganese hydride react at elevated tempera- tures to form [2-(C0)3MnB5Hlo] in which the Mn(C0)3 moiety is bound by two Mn-H-B bridge hydrogen bonds to the basal borons of a pentagonal-pyramidal Treatment of cobalt chloride with C5H5- and B5Hs- in cold THF gives rise to an extensive series of air-stable cobaltaboranes.One of these the violet [(C5H5Co),B4H6] has an octahedral Co,B4 cage in which the cobalt atoms occupy 33 (a) K. BaSe S. Heimhek and V. Gregor Chemand Znd. 1979,743; (b) Z.Janouiek,J. PleSek and Z. PMk 011. Czech. Chem. Ckmm. 1979,44,2904. 34 (a) J. S. Plotkin and S. G. Shore J. Organometullic Chem. 1979,182 C15; (b) E. L. Anderson K. J. Haller and T. P. Fehlner J. Amer. Chem. Soc. 1979 101,4390. 35 (a) M. B. Fischer and D. F. Gaines Znorg. Chem. 1979,18 3200; (b) J. R. Pipal and R. N. Grimes Inorg. Chem. 1979 18,252. The Typical Elements 19 adjacent vertices (Co-Co=2.557A) and are each co-ordinated to a cyclo-pentadienyl ring.Two hydrogen atoms occupy face-bridging positions approxi- mately above (0.78& the centres of the two C0,B faces; only a weak B--H interaction is inferred from the similarity of the Co-H and B-H From the same reaction a green tetracobalt tetraboron cluster compound [(q5-CsH,),Co,B4H4] can be isolated. The four cobalt atoms occupy contiguous posi- tions at the five-co-ordinate vertices of an eight-vertex polyhedron (2). Although (2) (Reproducedby permission from Inorg. Chem. 1979,18,257) possessing two fewer than the expected 18 framework electrons the cage suffers no significant distortion from regular closo dodecahedral geometry.36a Similar reac- tions give nickelaboranes NaBSHs +NiBrz+NaC5H5 + ~~oso-[1,6-(C~H~)~Ni~B~H~]+ ~Zoso-[1,7-(C,H,)~Ni,B~~~~] NaBSH,+[(C,H,),Ni] +Na/Hg + C~~S~-[(C~H,)~N~~B~H,] +nido-[(C5H5)4Ni4BSH5] The 20-electron [(C,H5)4Ni,B,&] also has a closo dodecahedral cage but the metal atoms occupy the low-co-ordination vertices; the Ni-Ni distance (2.354 A) is the shortest known metal-metal link in any type of metalloborane polyhedron and possibly indicates localized Ni-Ni bonding.36b The slightly volatile solid p-[q'-(C,HS)Be]B,H is formed in high yield by stirring a pentane slurry of KB,H mixed with excess of [C5H5BeC1]; the CSH,Be group bridges two basal boron atoms of a square-pyramidal cage (3).Treatment of the solid with bromine gives rather unexpectedly 1-BrB5H while decaborane( 14) is formed on heating with dib~rane.~~ N.m.r. studies on the halogenodiphosphine complexes [M(B,H,)X(dppe)] of nickel palladium and platinum suggest that all the 36 (a)J.R. Pipal and R. N. Grimes Znorg. am. 1979,18,257; (b) J. R.Bowser A.Bonny J. R.Pipal and R. N. Grimes J. Amer. 'CYtern Soc. 1979,101,6229. 37 D. F. Gaines K. M. Coleson and J. C. Calabrese J. Amer. Chem. Soc. 1979,101,3979. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway H(4) (3) (Reproduced by permission from J. Amer. Chem. Suc. 1979,101,3979) compounds have a static metallo-nido-pentaborane structure in which the metal occupies a bridging position between two basal boron A similar structure is assumed for (€3 &&Hg. 38 A molecular orbital study of the nidu-beryllaborane derivatives B5H,,BeX (X = BH4 B5HI0 Me or C5H5) has been carried out and as a result some interesting predictions were made possible regarding the isolation of as yet unknown om 0 I C(37)f -) (4) (Reproduced from J.C.S.Dalton 1979 117) 38 (a) J. D. Kennedy and J. Staves,Z. Naturforsch.,1979.34b,808; (b) N. S. Hosmane and R. N. Grimes Znorg. Chem. 1979,18 2886. J. Bicerano and W. N. Lipscomb Znorg. Chem. 1979,18 1565. The Typical Elements A number of metalloboranes have been described which have structures derived from that of hexaborane(10). The yellow air-stable 2-[carbonylbis(triphenyl-phosphine)irida]-nido-hexaborane prepared by the reaction [Ir(CO)CI(PPh&]+KBsH~+ [IrB5Hs(CO)(PPh& has the iridium in a basal position (4)."' Co-pyrolysis of pentacarbonyliron with pentaborane(9) in a hot-cold reactor (230-260/25 "C) gives the spontaneously inflammable liquid [B,H,Fe(CO),].The n.m.r. spectrum is consistent with structure (5) in which the metal is again located at a basal vertex site. The bridge hydrogen between the iron atom and a basal boron is fluxional and moves between the two basal Fe--B sites. Pyrolysis of (5) at 110"C gives a 30% conversion into the known H I 1-H [B4H8Fe(C0)3].41 Potassium hydride in dimethyl ether at -78 "C deprotonates [B5H,Fe(CO),]; treatment of the [B,H,Fe(CO),]- ion so produced with tris(tri- phenylphosphine)copper(I) chloride gives [Cu(PPh,),B,H,Fe(CO),] in which the copper bridges two basal boron atoms and is held relatively close to the basal plane (0.43A below) by BHCu bonding (6).42Pentaborane(9) and [C,H,Co(CO),] react (6) (Reproduced by permission from J.Amer. Chem. SOC. 1979,101,754) 40 N. N. Greenwood J. D. Kennedy and W. S. McDonald J.C.S. Dalton 1979 117. 41 S.G.Shore J. D. Ragaini R. L. Smith C. E. Cottrell and T. P. Fehlner Znorg. Chem. 1979,18,670. 42 M. Mangion J. D. Ragaini T. A. Schmitkons and S. G. Shore J. Amer. Chem. Soc. 1979,101,754. F.A. Hart A. G.Massey P. G.Harrison and J. H. Hollowa y together in a hot-cold reactor (225/75"C) to form the yellow volatile [l-(q5-C,H,)CoB,H,] in 2% yield. This compound is considered to be a direct analogue of B,Hlo with the apical BH group replaced by (q5-C,H,)Co. The observed fluxional behaviour like that of hexaborane(lO) is due to rapid migration of the bridging hydrogen atoms about the five basal The azaborane NB8HI3 reacts with tetrakis(tripheny1phosphine)platinum in benzene at 60 "C to give nido-[9,9-(PPh,),-6,9-NPtB8HI1]; the proposed structure is derived from that of the [BloH14]2- anion where the two6,9-BH2-vertices have been replaced by both an NH and a Pt(PPh,) Chromatography of the involatile residue from the B,H,/[C5H,Co(CO)2] reaction (see above) yielded the air-stable [(qS-C,H,)CoB,Hl,] which has n.m.r.properties consistent with a BloH14-like structure where cobalt substitution has occurred at position 2.43 An X-ray structure determination on 9-triethylamino-6-thiadecaborane( 1l) 9- NEt,-6-SB,Hll shows the triethylamine ligand to be attached to the thiaborane cage in an exopolyhedral manner at B-9 with a B-N distance of 1.600 A; this position of addition probably models the initial mode of interaction of alkenes and alkynes during the hydroborations by SB,HIl described last year.The sulphur atom occupies position 6 and is bound to three borons with an average B-S distance of 1.927 A; the bridging hydrogens on the open face are significantly displaced toward B-9 and away from the Formation of the platinathiaboranes [9,9-(PPh3)2-6,9- SPtBsHlo] (7a) and [8-OEt-9,9-(PPh3)2-6,9-SPtB8H9] (7b) from the reaction of [Pt(PPh,),] with either 1-SB,H or SBllHll in ethanol is thought to occur via a degradative insertion process in which the thiaboranes are degraded initially to an SB (74 (7b) (Reproducedby permission from Inorg. Chem. 1979,18 2642) Ammonium polyselenide reacts with NaBllH14 to give the red anion [BllH,Se3]2- in low yield.The ion is a disubstituted derivative of [BI1HlJ2-,the Se chain being 43 R. Wilaynski and L. G. Sneddon Inorg. Chem. 1979,18 864. 44 K.B& A. Peti-ina B. %br V. PetriEek K. Mal9 A. Linek and I. A. Zakharovl Chem. and Id. 1979,212. '' (a) T. K. Hilty and R. W. Rudolph Inorg. Chem. 1979,18,1106; (b) T.K.Hilty D. A. Thompson,W. M.Butler and R. W. Rudolph Inorg. Chem. 1979.18.2642. The Typical Elements (8) (Reproduced by permission from Inorg. Chem. 1979,18,755) bound to two adjacent boron atoms of the closo cage (8). "B N.m.r. studies suggest that [B1,H9Se3l2- is fluxional at room temperat~re.~~ Icosahedral stibaboranes have been made by the reactions THF B10H14+ SbCl +Et3N +Zn -+1,2-BloHloSb2 Partial cage degradation of the two stibaboranes using piperidine followed by addition of C5H and CoCl, allows isolation of the cobalt derivatives [C5H5Co(7,8- B,H,AsSb)] and [C5H5Co(7,S-B,H9Sb,)].47 Borane Anions and their Derivatives.-The rate of hydrogen-deuterium exchange in MBH4-MBD4 mixtures dissolved in ethers depends markedly on M being in the order Li(diethy1 ether) > Na(diglyme) > K( 18-~~own-6).~~ In the presence of acetic acid the tetrahydroborate ion in acetonitrile is rapidly converted into [H,BOCOCH,]- and previous kinetic studies of the hydrolysis of [BH,]- in such solutions actually refer to the hydrolysis of [H3BOCOCH3]-.49 Highly pure free metals are precipitated by sodium tetrahydroborate from aqueous solutions of Ag Au Pd and Pt salts.Under acidic conditions the finely divided metals are found to absorb significant amounts of hydrogen produced by the concurrent hydrolysis of the tetrahydr~borate.~'" Chromate and dichromate ions are reduced to Cr'" in the presence of aqueous tetrahydroborate but it is considered that the hydrolysis products [BH,OH]- [BH,(OH),]- and [BH(OH),]- are actually responsible for the reduction 46 G. D. Friesen J. L. Little J. C. Huffman and L. J. Todd Znorg. Chem. 1979 18,755. 47 J. L. Little Inorg. Chem. 1979,18 1598. 48 I. A. Oxton A. G. McInnnes and J. A. Walter Canad. J. Chem. 1979,57 503. 49 B. S. Meeks and M. M. Kreevoy Inorg. Chem. 1979,18,2185; J. Amer. Chem. Soc. 1979,101,4918.(a) N. N. Mal'tseva 2.K. Sterlyadkina I. G. Erusalimchik and V. I. Mikheeva Zhur. neorg. Khim 1979 24,822; (b) V. S. Khain and V. F. Martynova Zhur. neorg. Khim. 1979,24 46. 24 F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Tetra-t-butoxytriberyllium bis(tetrahydroborate) (Bu'O),Be,(BH,), has the three beryllium atoms linked linearly by the oxygen atoms from the four t-butoxy- groups. Each of the BH groups is joined to an outer beryllium by two H-bridge~.'~" In the gas phase monomeric Me,AlBH and Me,GaBH adopt C, symmetry with bidentate BH groups. The M-C M-B and M-H bond lengths change by only 0.01-0.04 8 on substituting gallium for aluminium consistent with the identical values assigned by Pauling to the tetrahedral covalent radii of A1 and Ga."* Zinc tetrahydroborate has been prepared by treating ethereal solutions of zinc chloride with alkali and alkaline earth tetrahydroborates; a number of complex zinc tetrahydroborates were also isolated MZn(BH& * nL (M = Li Na K Rb or Cs) and MZn(BH4) * nL (M = 2Li Ca Mg or Ba) where L = Et,O THF or digl~me.~* Zinc tetrahydroborate also complexes with niobocene carbonyl hydride [(C,H,),Nb(CO)H] the hydrogen atom being thought to bridge the two metals.The BH units are each bonded to zinc by two BHZn bridges.s3 Vanadium and iron trichlorides react with an excess of sodium tetrahydroborate in monoglyme (L) to form NaV(BH,) * 3L and NaFe(BH,) -3L respectively. The iron complex gives ferrocene when treated with cyclopentadiene and [Fe(NH,)J (BH4)2 when treated with ammonia.s4 The water-sensitive lanthanide,ssb and uraniums6 tetrahydroborates M(BH4)3 -nTHF (M = Y La Ce Pr Nd or Sm) and U(BH,),( 18-crown-6) are prepared similarly in THF.A crystal structure determination on tetrahydroboratotris(hexamethyldisily1-amido) thorium(Iv) [C1Th(N(SiMe3),},] +LiBH -* [BH,Th(N(SiMe,),},] shows that the BH is bonded in terdentate fashion to the thorium (Th-B = 2.61 8,); a similar structure is suggested for the uranium analogue.57 Two crystalline forms of uranium(1v) tetrahydroborate can be made depending on whether gaseous U(BH,) is condensed at 20 "C or -80 0C.s8 Mass spectra show uranium(1v) tetrahydroborate to be monomeric in the gas phase;59960 at electron energies greater than 30 eV the dominant fragmentation process is the successive loss of BH ligand~.,~ The i.r.spectra of U(BH,) and U(BD,) as gaseous samples at 23 "C and in inert matrices or thin films at low temperature have been recorded.600 Broad-band U.V. photolyses of U(BH,) and U(BD,), either as gases or in THF solution give U(BXJ3 B2& and X (X = H or D) as the primary products.60* 51 (a) B. Morosin and J. Howatson J. Inorg. Nuclear Chem. 1979 41 1667; (b) M. T. Barlow A. J. Downs P. D. P. Thomas and D. W. H. Rankin J.C.S. Dalton 1979 1793. 52 V. I. Mikheeva N. N. Mal'tseva and N. S. Kedrova Zhur. neorg. Khim. 1979,24,408. '' M. A. Porai-Koshits A. S. Antsyshkina A. A. Pasynskii G. G. Sadikov Y. V. Skripkin and V. N. Ostrikova Inorg. Chim. Acta 1979,34 L285; Koord. Khim.1979,5 1103. 54 V.D. Makhaev A. P. Borisov N. G. Mozgina G. N. Boiko and K. N. Semenenko Izuest. Akad. Nauk S.S.S.R.neorg. Muter. 1979 14 1726. 55 (a) U. Mirsaidov and A. Kurbonbekov Dokludy Akad. Nauk Tadzh. S.S.R.,1979 22 313; (b) U. Mirsaidov A. Kurbonbekov T. G. Rotenberg and K. Dzhuraev Izuest. Akad. Nauk S.S.S.R.neorg. Muter. 1979 14 1722. 56 D. C. Moody R. A. Penneman and K. V. Salazar Znorg. Chem. 1979,18,208. 57 H.W.Turner R. A. Anderson A. Zalkin and D. H. Templeton Inorg. Chem. 1979 18 1221. 58 P. Charpin H. Marquet-Ellis and G. Folcher J. Inorg. Nuclear Chem. 1979 41 1143. 59 P. B. Armentrout and J. L. Beauchamp Inorg. Chem. 1979,18 1349. 6o (a) R.T. Paine R. W. Light and M. Nelson Spectrochim. Acta 1979,35A 213; (b) R. T. Paine P. R.Schonberg R. W. Lighr W. C. Danen and S. M. Freund J. Znorg. Nuclear Chem. 1979.41 1577. The Typical Elements Triphenylphosphine complexes of copper and silver containing car-boxylatotrihydroborate ions (H,BCO,R-; R = H Me or Et) have been isolated as stable crystalline solids having the compositions [(Ph,P),Cu(H,BCO,R)] and [(PPh,),Ag(H,BCO,R)]. The boron ligand is bidentate in the copper complexes but only unidentate in those of silver.61 The easily accessible potassium tri-isopropoxyhydridoborate KHB(OPr% is only a mild reducing agent. However it rapidly transfers its hydrido-group to both simple and highly hindered trialkylboranes forming potassium trialkylhydroborates which are reducing agents of exceptional activity and nucleophilicity.62 Similarly addition of one mole of trialkylborane to a THF solution of lithium tri- methoxyhydroaluminate results in the displacement of aluminium methoxide as a polymeric gel and the quantitative formation of LiR,BH; the latter can then be used directly for the stereoselective reduction of organic functional groups without the necessity of removing the A1(OMe)3.63 Reviews have described the use of organo-hydroborates in organic reductions64 and in organometallic Trimethyl-boron and -gallium react with 3-methylpyrazole to yield two isomers (9) of the dimer [Me,E(Mepz)],; trimethylindium gives only one isomer possibly (ga)."" Me Me Me Me Chloro[hydrotris-(1-pyrazolyl)borato]copper(11) made in good yield by the reac- tion EtOH 2CuCl,(anhyd.)+2Na[HB(l-pz),] -[CuCl(HB(l-pz),}] +NaCl is dimeric in the solid state with symmetrical chloro-bridges between the two copper atoms; the ligand (10)is terdentate.Magnetic susceptibility data recorded down to 2 K show the presence of a ferromagnetically coupled ground state (2J/k = 48.6') for the dimer.67a Ligand (10) is also terdentate in bis[hydrotris-(1-pyrazolyl)borato]copper(11).67 61 J. C. Bommer and K. W. Morse Inorg. Chem. 1979,18 531. 62 C. A. Brown and J. L. Hubbard J. Amer. Chem. SOC.,1979,101,3964. 63 H. C. Brown S. Krishnamurthy and J. L. Hubbard J. Organometallic Chem. 1979,166,271; see also ibid. p. 281 and S. Krishnamurthy and H. C. Brown J. Org. Chem. 1979 44,3678. 64 H. C. Brown and S. Krishnamurthy Aldrichimica Acta 1979 12 3. 65 J.A. Gladysz Aldrichimica Acta 1979,12 13. '13 L. K. Peterson and K. I. ThC Canad. J. Chem. 1979,57 2520. 67 (a) S. G. N.Roundhill D. M. Roundhill D. R. Bloomquist C. Landee R. D. Willett,D. M. Dooley,and H. B. Gray Inorg. Chem. 1979,18,831;(b) A. Murphy B. J. Hathaway and T. J. King J.C.S. Dalton 1979 1646. F.A. Hart A. G.Massey P. G.Harrison and J. H. Holloway H I A series of poly-(1-pyrazolyl)borate complexes of copper(1) and silver(I) ML(pz,B,-,) containing anions such as [H2Bpz2]- [Ph,Bpz,]- [HBpz,]- and [Bpz4]- has been described. The tri- or tetra-pyrazolyl ligands and L appear to adopt a distorted tetrahedral co-ordination about the metal; 'H n.m.r. spectra of the [Bpz,]-complexes show that all the pyrazolyl groups are equivalent at room temperature.The anions [HBpz,]- and [Bpz,]- are probably only bidentate when L is 1,2-bis(dimethylar~ino)benzene.~~ Hydridotris-(1-pyrazolyl)borate when used as a ligand to thorium or uranium in the complexes [M(CsH5)2C12- (HBpz3)](x = 1or 2) stabilizes the latter against disprop~rtionation.~~" Potassium tris-(3,5-dimethylpyrazolyl)borate reacts with [Re(CO),Cl] to form [Re{HB(3,5-Me2C3HN,)3}(CO)3] in which the borate ligand is terdentate; rather unexpectedly bromine attacks the pyrazolyl rings at position 4 to give [Re{HB(3,5- Me,-4-BrC,N2),}(CO),] without displacement of carbon monoxide.69b Potassium dihydrobis-( 1-indazolyl)borate prepared from KBH and indazole has been used to form complexes of Cu" Ni" Co"I Mn" and Fe"'; the ligand is bidentate and co-ordination occurs through the nitrogen atom at position 2 of the indazole ring in all cases and except for the copper compound the nitrogen at position 1 is also involved in forming a bridge with an adjacent metal ion.A square-planar geometry involving chlorine bridges is suggested for the CuII complex whereas the others are given an octahedral polymeric In methanol-water solutions of HC1 at -78 "C the octahydrotriborate ion reacts to form one mole of hydrogen and a solution of B3H7(OH2); warming to -45 "C causes complete hydrolysis to boric acid and hydrogen. Addition of base at -78°C produces [B,H70H]- but at slightly higher temperature a quantitative base- catalysed disproportionation [B,H,OH]-+20H-+H20 -+ 2[BH4]-+[B(OH),]-Rapid intermolecular H-D exchange occurs when attempts are made to prepare Na'[B3D,H]-or Na+[B3H7D]-.70b An assignment of the internal modes of the octahydrotriborate ion in CsB3H has been made together with some of the librational modes in the The ligand-free copper(1) compounds CuB,H 0.M.Abu Salah M. I. Bruce and J. D. Walsh Austral. 1.Chem. 1979,32,1209;0.M. Abu Salah G.S. Ashby M. I. Bruce E. A. Pederzolli and J. D. Walsh ibid. p. 1613. (a) K. W. Bagnal1,A. Beheshti J. Edwards,F. Heatley and A. C.Tempest J.C.S. Dalton 1979. 1241; (b) J. A. McCleverty and 1. Wolochowia. J. Organometallic Chem. 1979,169,289;(c) S. A. A. Zaidi and M. A. Neyazi Transition Metal Chem. 1979,4 164. 'O (a) W. L. Jolly J. W. Reed and F. T. Wang Inorg. Chem. 1979 18 377; (b) M.A. Nelson and G. Kodama Inorg. Chem. 1979,18,3276. (a) J. Tomkinson C. J. Ludman and T. C. Waddington Spectrochim.Acta 1979,35A 117; (b) R. K. Hertz R. Goetze and S.G. Shore Inorg. Chem. 1979,18 2813. The Typical Elements 27 and Cu2BloH, have been prepared by treating the corresponding bis(tri- phenylphosphine) complexes with diborane in methylene chloride at 0 0C:71b [(PPh,)2CUB,H,] +B2H6 -* 2BH3PPh3+CUB~H~ [{(PP~~)~CU}~BIOHIOI +B2H6 + 2BH3PPh3+ C~2B1oHlo It is suggested that the single line in the “B n.m.r. spectrum of the [B8H8]’- ion in water arises from a fluxional DZd(i.e.dodecahedral) structure in which the borons are permuted between the two distinct D, magnetic environments the CZv(square face bicapped trigonal prism) geometry serving as a translational structure for the permutation.“B N.m.r. spectra of the [B,H,]’- ion in other solvents where ion-pair formation is likely are more complex and further experimental work on these systems is urged before a discussion of the spectra is attem~ted.~’ The pyrolytic reaction between tetraethylammonium chloride and potassium tetrahydroborate in the presence of water allows a one-step preparation of [B,oHlo]2- to be accomplished. The optimum conditions appear to be 16 h at 187 “C (79% yield); below 170 “C no formation of [BloH1o]Z- occurs and at 210 “Cthe yield drops to 63% .73a Sodium tetrahydroborate and triethylamine-borane react in the presence of aluminium chloride at 160-180°C to give Na2BloHlo. When the reaction is carried out in a steel bomb at low pressure using decane as solvent the product is Na,B,2H,2.736 Using bond-length based bond enthalpies the quantity ‘total enthalpies of the skeletal bonds divided by number of cage atoms’ [C E(B-B)/n] has been evaluated for [B,H,]’- ions.It decreases in the order B,=,>B8>B9 and then markedly increases to Blo and B12. This trend is consistent with the relatively high stability of [BloHlo]2- and [Bl2Hl2I2- as indicated by thermal interconversions of [B,H,]’-ions.74 Carbaboranes.-The carbaboranes and their derivatives have been the subject of recent reviews.75 New methods of separating highly reactive boron compounds are always welcome. This year it has been demonstrated with 20 derivatives that high-pressure liquid chromatography can be used as a routine method for the separation of low-volatility and unstable metallocarbaboranes without their undue exposure to air and light.’,=,“ The photoelectron spectra of 2-halogeno- and 2,4-dihalogeno- 1,6-dicarba-cluso- hexaboranes have been recorded and An 84% yield of the six possible B-B-bonded isomers of the coupled-cage systems occurs when 2,4-C2BsH7 is subjected to mercury-sensitized photolysis; the isomers were readily separated using gas-liquid chromatography.” Isomerization of these coupled species occurs during attempts to introduce metals into the frame- work; hence to save time the unseparated photolysis reaction mixtures were treated 72 D.A. Kleier and W. N. Lipscomb Inorg. Chem. 1979,18 1312. 73 (a) K.-M.Chang and H. Chu Hua Hsueh Hsueh Pao 1978 36 315; (b) V. V. Volkov and I. S. Posnaya Ixvest. Sibirsk. Otdel. Akad. Nauk S.S.S.R.,Ser. Khim. Nauk 1979,4,88. 74 C. E. Housecroft R. Snaith and K. Wade Inorg. Nuclear Chem. Letters 1979 15,343. 75 V. I. Stanko V. A. Brattsev and S. P. Knyazev Rurs. Chem. Rev. 1979 48 130; J. B. Leach in ‘Organometallic Chemistry’ ed. F. G. A. Stone and E. W. Abel The Chemical Society London Vol. 7 1978 p. 63; R. N. Grimes Coordination Chem. Rev. 1979,28,47. 76 (a) Z. PlzBk,J. PleSek and B. Stibr,J. Chromatog.,1979,168,280; (b) G.A. Beltram and T. P. Fehlner J. Amer. Chem. Soc. 1979,101,6237. 28 F.A. Hart A. G. Massey P. G. Harrison and J. H. Holloway with [C,H,Co(CO),]. After two hours at 220°Csix closely related red-brown metallacarbaboranes ‘(C,H,)2C02(C2B,~)2’, were isolated for which two types of structure were suggested (i) a coupled system containing one cobalt atom in each cage and (ii) a two-cage compound consisting of a dicobalt metallacarbaborane bound to an unmetallated C2B,H,unit.At 220°Ceach compound undergoes a single rearrangement which establishes equilibrium mixtures of pairs of specific isomers,77e.g. Scheme 3. 220“C ‘Y Scheme 3 (Reproduced by permission from Inorg. Chem. 1979 18 2165) The class of nido-carbaboranes with a pentagonal pyramidal structure has been completed by the synthesis of l-halogen0-2,3,4,5,6-pentamethyl-2,3,4,5,6-pentacarba-nido- hexaborane(6) cations (Scheme 4).78 r l+ X Me $Me BX BX3 M$ri2 BX,(or AlCl,) or AIa; GeMe Me Me Me Me Me L X=C1.Br or I Scheme 4 Rather similar reactions have also been used to prepare B2C4 nido-carba-hexaboranes” and a B4C4carbaborane of unknown structure (Scheme 6).80n 77 J. S. Plotkin and L. G. Sneddon Inorg. Gem. 1979 18 2165. 7n P.Jutzi A. Seufert and W. Buchner Chem. Ber. 1979 112 2488. 79 H.-0. Berger H.Noth and B. Wrackmeyer Chem. Ber. 1979 112,2884. (a) W. Siebert and M. El-Din M. El-Essawi Chem. Ber. 1979 112 1480;(b) G.K.Barker M. Green F. G. A. Stone A. J. Welch T. P. Onak and G. Siwapinyoyos J.C.S. Dalton 1979 1687. The Typical Elements Me H Me Me Me Me Br Br Et Et Scheme 5 Et Et THF /-\BM + K -K2S + (EtC)4(BMe)4 -AS/ Scheme 6 The nido-[2,3-Me2C2B4Hs]- anion reacts with anhydrous mercuric chloride in THF at room temperature to give (Me,C,B,H,),Hg in which the metal is bound to two carbaborane ligands via B-Hg-B three-centre two-electron bonds (Scheme 7).38b Similar platinum derivatives have been isolated via the insertion of zero- H Me B-C 180"C,benzene i nid0-5,5'-[Me,C~'~B,H~]~ Scheme 7 valent platinum species into the bridging B-H-B bonds of 2,3-dicarba-nido- hexaborane(8)s and monocarba-nido- hexaborane(9),*" e.g.Scheme 8. In the deep-red [{2,3-Me2C,B4H4}2FeH2] two pentagonal-pyramidal carbaborane ligands are face-bonded to the iron atom the C2B planes being inclined at 7.8" such that the methyl groups on carbons C-3 and C-3' are forced close together (in fact 0.5 A closer than the sum of the van der Waals radii of two methyl groups).Thus the tilt is in the opposite direction to that expected if the metal-bound hydrogen atoms were not present and indicates that these hydrogens are wedged between the F.A. Hart A. G.Massey P.G. Harrison and J. H.Holloway H U Et3P' \H R R C-C R=HorMe Scheme 8 polyhedra on the side of the complex furthest removed from the C-CH groups (11).81 P (11) (Reproduced by permission from Inorg. Chem. 1979,18 263) A two-boron cage expansion has been achieved by heating trimethylboron with nido-2,3-C2B4H8 when 2,3,4,5,6,8-Me6-closo- 1,7-C2B6H2 is formed together with the known one-boron expansion product 1,3,5,6,7-Me,-closo-2,4-C2B5H2. When 2,3-Me2-nido- 2,3-C2B,H6 is used the principal product is the permethylated closo- Me7C,B,.82" From the equilibria established between (B-Me),-2,4-C2B,H7-,(x = '' J.R. Pipal and R. N. Grimes Znorg. am.,1979,18,263. '* (a) A. P. Fung E. W. DiStefano K. Fuller G. Siwapinyoyos,T. Onak and R. E.Williams Znorg. Chem. 1979,18,372; (b) T. On& A. P. Fung G. Siwapinyoyos and J. B. Leach Znorg. Chem. 1979,18,2878; (c) M. Green J. L. Spencer and F. G. A. Stone J.C.S. Dalton 1979 1679. The Typical Elements 31 1 2 3 or 4) isomers at 300 "C it is evident that the methyl positional preference follows the order 3 >1,7>5,6 for closo-dicarbaheptaboranes;rearrangement of the cage is the assumed mechanism and not simple methyl migration. In a carefully controlled thermal rearrangement of 5,6-Me,-2,4-C2B,H the 1,5-isomer was formed prior to the production of 1,3- 35 or 1,7-isomers the allowed equilibria being:82b Oxidative insertion reactions of zero-valent nickel and platinum complexes with closo-carbaboranes lead to a wide variety of metallocarbaboranes e.g.82c [Ni(~od)(PEt,)~]+ doso-1,7-Me,-1,7-C,B6H6 + clos0-[4,5-Me~-6,6-(PEt~)~-4,5,6-C~NiB~H~] Treatment of nido- and uruchno- carbaboranes with sulphur in the presence of aluminium trichloride yields thiols in which the HS groups are bonded to the most negative boron atoms; isomers result if several boron atoms carry a similar charge:33b Ma3 nidu-5,6-c2B8Hl2+S -3-HS-5,6-C2B8Hll +4-HS-5,6-C2B8Hll AICI, arachno-6,9-C2B8H1,+ S -l-HS-6,9-C2B8Hl3 4-IO-HS-5,6-C2B8Hil A full assignment of peaks has been made for the "B n.m.r.spectra of substituted dicarba-cluso-undecaborane(1 1) compounds derived from 2,3-Me,-2,3-C2B,H and 4,7-(OH),-2,3-Me,-2,3-C2B9H,.83 The pK values of C2BloHllSH and C,BloHllSCH2C02H isomers have been used to obtain an experimental measure of the charge distribution on particular skeletal atoms in ortho- metu- and puru-icosahedral carbaborane~.~~ Oxidation of 9-SH- 1,2-C2BloHl with hydrogen peroxide in acetic acid as 80-90 "C gives an 82% yield of 9-S03H-1,2-CzBloHll.8s" The first compound containing a four-membered ring fused to a dicarbaborane cage has been prepared by low-pressure flow-pyrolysis of the diazo-derivative 1-N2CH-2-Me-C2BloHlo and was assumed to arise from attack of the generated carbene on the neighbouring methyl group (Scheme 9).85b N2 H*C-CH;! CH Me 4oo-~'c I i Me H Me Me -c-c [,/ c-c + c-c + c--c + c--c"I \L BlOHlO \/ \/ \/ BIOHlO BloHlo BlOHlO B&lO Scheme9 83 F.R. Scholer R. Brown D. Gladkowski W. F. Wright and L. J. Todd Inorg. Chem. 1979,18,921. 84 J. PleSek and S. Heiininek Coll. Czech. Chem. Comm. 1979,44 24. 85 (a) L.I. Zakharkin I. V. Pisareva and T. B. Agakhanova Izvest. Akud. Nuuk S.S.S.R.,Ser. khim. 1978,2831;(6)R.Chari G. K. Agopian,andM. Jones J. Amer. Chem. Soc. 1979,101,6125; (c) L. 1. Zakharkin and I. S. Saveleva Izvest Akad. nauk S.S.S.R.,Ser. khim. 1979,1381;(d) A. I. Yanovskii N. G. Furmanova Yu. T. Struchkov N. F. Shemyakin and L. I. Zakharkin Izvest Akud.Nuuk S.S.S.R.Ser. khim. 1979 1523. F. A. Hart A. G.Massey P. G.Harrison andJ H. Hollo wa y J32 Et2 N CUCl + Li c-c CH2 Lcu/")(30%) \I 'c-c BlOHlO \/ BlOHlO Scheme 10 Heterocycles are formed on reaction of l-lithio-2-(dialkylarnino)methyl-ortho-carbaboranes with the chlorides of copper palladium and platinum (e.g. Scheme The five- and six-membered rings in the heterocycles (12) and (13)are very nearly planar.85d R. ..H. -Lithiation of 1,2- and 1,7-C2BloH12 by butyl-lithium followed by addition of copper(1) chloride produces l-Cu-l,2-(0r 1,7-)C2BloHll which are useful inter- mediates in the formation of allenyl- and vinyl-carbaboranes e.g. ~-CU-~,~-C~B~~H~~-+ 1-CH2=C=CH-1,2-C2BloHll ref. 86 +BrCH,CrCH 1-Cu-1,7-C2BloHll +ICH=CHR -B 1-CHR=CH-1,2-C2BloH11 ref.87 Acrylonitrile CH,=CHCN adds smoothly to the C-H bonds of 1-R-1,2-C2B10Hll(R = H CH2CH2CN Me Ph or CH2=CMe) in the presence of basic media to give high yields of the corresponding cyanoethyl derivatives.X8a Gas-phase isomerization of 3-aryl- 1,2-dicarbaboranes at 550-600 "C leads to the formation of approximately equal amounts of 2- and 4-aryl- 1,7-di~arbaboranes.~~~ A detailed analysis has been made of the distribution of valence electron density in [Bl2Hl2I2- and the isomers of C2BloH12. The main electronic charge is shown to reside within the sphere inscribed within the icosahedra a significant proportion of the electron density being found at the centre of this sphere. It is concluded that the network atoms are maintained in position by the attraction of the spatial charge.89 The molecular parameters of icosahedral 1,12-PCBloH11 and 1,12-AsCBloHl have been determined by electron diffraction; in particular B-P = 2.049 A and B-As = 2.137 A."" 86 L.I. Zakharkin A. I. Kovredov Zh. S. Shaugumbekova. and A. V. Kazantsev Zhur. obshchei Khim.,. 1979,49,1169. L.I. Zakharkin A. I. Kovredov and V. V. Kobak Zhur. obshcheiKhim. 1978,48,2132. (a)V. N.Kalinin 0.M. Zurlova and L. I. Zakharkin J. Orgunometullic Chem. 1979,166 C37; (6)V. N.Kalinin N. I. Kobel'kova and L. I. Zakharkin J. Orgunometullic Chem. 1979,172 391. L.A.Gribov T. P. Klimova and M. M. Raichstatt J. Mol. Structure 1979,56 125. 90 V. S. Mastryukov E. G. Atavin L. V. Vilkov A. V. Golubinskii V. N. Kalinin G.G. Zhigareva and L. I. Zakharkin J. Mol. Structure 1979,56 139. The Typical Elements A number of B9C2 derivatives of mercury copper and gold have been prepared by reactions such as NaB9C27'8(NC5H5)9Hlo '*2A~(PPh3)3(NC5H5)4Hlo] + [AuCl(PPh,)]-+ [B9C2 NaB9C27*8(NC5H5)9Hlo+ [CuCl(PPh,)],+ [B9C21'2C~(PPh3)3(NC5H5)4Ht0] NaB,C27'8(NC5H5)9Hlo 1~2(NC5H5)4Hl,}2] + HgC12+ [3,3'-Hg{B9C2 TlB9C2'*2T13H1 + [B9C21'2(HgPPh3)3Hl + [HgC12(PPh3)2] ,] The latter mecurial has the Hg atom co-ordinated almost linearly by tri-phenylphosphine and the unique boron atom of the C2B3 face (Hg-B=2.20& (14).91a (14) (Reproducedfrom J.C.S. Dalton 1979,619) The eleven-atom polyhedral molecule closo-[C,H,CoB9H9CNMe,] (15) is formed by first deprotonating B9H1 ,CNMe3 with NaH and then treating the anion with a mixture of cyclopentadienylsodium and cobalt(I1) chloride; on the "B n.m.r.time-scale it is fluxional at 70 "C but static at -40 "C. Thermal degradation gives B,H9CNMe for which a symmetrical bicapped square-antiprismatic structure with the CNMe group in an apical position is sugge~ted."~ The small value of the slip parameter in [3-PPh3-3-CO-4-C,H,N-3 1,2- RhC2B9HIO]suggests that the structure can be regarded as closo. The RhCOPPh fragment is rotated by about 90" from the theoretically expected orientation which is 91 (a) H. M. Colquhoun T. J. Greenhough and M. G. H. Wallbridge J.C.S. Dafton,1979,619; (b) R.V. Schultz J. C. Huffman and L. J. Todd,Znorg. Chem. 1979,18,2883. E A.Hart A. G.Massey P. G.Harrison andl H. Holloway (15) (Reproduced by permission from Inorg. Chem. 1979,18 2883) parallel to a line joining the two‘ortho’carbon atoms; presumably this is due to steric interaction between the rhodium ligands and the pyridine ring (16).92 The closely (16) (Reproduced from J.C.S. Chem. Comm. 1979,472) related [3,3-(PPh3)*-3-H-3 1,2-RhC2B9HI1] (17) is a useful starting material for the synthesisof many other derivatives of the RhC,B9Hl cluster. Nitric acid or nitrogen dioxide converts (17) into [3-PPh3-3,3-N03-3,1,2-RhC2B9Hll] (18) which contains a bidentate nitrate group; addition of a further molecule of triphenylphosphineto (18) gives [3,3-(PPh3)2-3-N0,-3,1,2-RhC,B,H,,I in which the nitrate is uniden- tate. If the triphenylphosphine is added to (18) in the presence of either H2 or HCI in THFthe unidentate nitrate is replaced by H or Cl.93 Sulphuric acid and (17) react to 92 R.G. Teller J. J. Wilaynski and M. F. Hawthorne J.C.S. Chem. Comrn. 1979,472. 93 Z.Demidowin R. G. Teller and M. F. Hawthorne J.C.S. Chem. Comm. 1979,831. The TypicalElements give [3,3-(PPh3),-3-OS0,H-3,1,2-RhC~B9Hl~ 3 the bisulphate group of which can be exchanged for C1 or Br by treatment with NaCl or NaBr; the 31Pn.m.r. spectrum was interpreted in terms of the eq~ilibrium:~~ .o /O\/ (~arb)(PPh~)~Rh0S0,H $PPh3+ (carb) PPh3Rh ‘0’ ‘OH Nido cages having 11 12 and 13 vertices have been obtained via the reactions Me4C4B8H8+ [C,H,Co(CO),] [C5H5CoMe4C4B7H7] isomer 1 + [C~HSCOM~~C~B~H~]isomers I and I1 [Me4C4B8H812- + CoC12+ HCl+ O2+ C5H5-P [C5H5CoMe4C4B7H7] isomer I + dC5H5Cdv 5-C5H4)1CMe&B~H~l (19) + [c#&OMe4C4B8H8] The products are stable enough to be separated by thin-layer chromatography in the open air.95 The C4B8 cage in (19)has a basket-like structure in which the four carbon CP4 CPI (19) (20) (Reproduced by permission from J.Amer. (Reproducedby permission from Inorg. Chem. Gem. SOC.,1979,101,4172) 1979,18 1936) 94 W. C. Kalb R G. Teller and M. F. Hawthorne J. Amer. Chem. SOC.,1979,101 5417. 95 W. M. Maxwell and R. N. Grimes Inorg. Chem. 1979 18 2174. 36 F A. Hart A. G.Massey P. G.Harrison and J. H. Holloway atoms occupy contiguous positions on the open face. One of the C-Me units is co-ordinated to only two framework atoms and the 'extra' hydrogen is attached to this bridging carbon.96 In one isomer of [(C5H5),Co,Me4C4C4B6H6] the two pentagonal-pyramidal C,H,CoMe,C,B,H units are partially fused together along their C2B3 faces such that the pairs of carbon atoms on the two pyramidal units are separated by non-bonding distances; the molecule resembles a severely distorted icosahedron with a large opening on one side (20).97 Halides.-The B-AgC1 reaction as a means of forming "B- "B- or 35C1-labelled boron trichloride has been reinvestigated.At 860 "C the yields are 77% based on boron and 96% based on AgCl when boron is in No acid-base association could be detected between boron trifluoride and nitrogen trifluoride at -114 oC.98b Microwave spectra of three very weak complexes of boron trifluoride ArBF, N2BF3 and OCBF, have been recorded.The mole- cules are symmetric tops with the BF moiety only slightly distorted out of the plane by one degree upon bond formed B-Ar = 3.334 A B-N = 2.864 A,B-C= 2.886 A (these values are longer than the expected sum of covalent radii and can only be rationalized as a sum of van der Waals radii thus allowing estimates to be given for the van der Waals radius of boron trifluoride ca. 1.3-1.4 An n.q.r. study of BX -NMe complexes shows that the ionic character of the B-X bond decreases in the order expected from the electronegativity of the halogen atoms. For X = C1 or Br all the observed resonance lines fade out far below the melting points which was attributed to the hindered rotation of the BX group about the BN b0nd.l" Boron trichloride dissolves in acetonitrile to give a non-conducting solution which contrary to previous work is interpreted as due to the presence of a molecular solute C1,BNCMe."' Tetramethylethylene diamine TMED reacts instantly with boron trifluoride etherate to give the highly insoluble TMED .2BF,.The diamine also reacts readily with typical RBHP species to form both the mono- and bis-adducts which are air-stable and can be stored for long periods without apparent change. Since boron trifluoride removes TMED from these adducts rapidly and completely precipitating out TMED -2BF3 it is found that the monoalkylboranes can be conveniently purified and stored as their TMED adducts.Similarly ethylenediamine en can be used to store dialkylboranes as (R,BH),en. *02 A tensiometric titration between boron trifluoride and Sn(NR,) (R =Me or Et) showed that the 3:1adducts are formed in which two molecules of BF are bound to the nitrogen atoms and one to tin; the initial co-ordination site is thought to be the tin atom.lo3 The basicity of the phosphines arsines and stibines MenE(CF&-, (n= 0-3) towards boron trihalides borane trimethylboron and dimethylboron y6 R. N. Grimes J. R. Pipal and E. Sinn J. Amer. Chem. SOC.,1979,101 4172. 97 J. R. Pipal and R. N. Grimes Inorg. Chem. 1979 18 1936. 98 (a)R. K. Pearson J. Inorg. Nuclear Chem. 1979,41,1541; (b) S. C. Aldersley J. C. G. Calado and L. A. K. Staveley J. Inorg. NuclearChem.1979 41 1269. " D. R. Armstrong Inorg. Chim. Actu 1979 33 177. loo T. Okuda H. Ishihara K. Yamada and H. Negita Bull. Chem. Soc. Japan 1979,52,307. 1. R. Beattie P. L. Jones J. A. K. Howard L. E. Smart C. J. Gilmore and J. W. Mitt J.C.S. Dalton 1979,528. 102 H. C.Brown B. Singaram and J. R. Schwier,Inorg. Chem. 1979,18,51; H. C. Brown and B. Singaram Inorg. Chem. 1979 18 53. C. C. Hsu and R. A. Geanangel Inorg. Chim. Actu 1979,34 241. The TypicalElements bromide is in the order Me2ECF3 >MeE(CF,)* >E(CF3)3 for constant E (=P,As or Sb). A complete vibrational analysis of the 1:1and 1:2 adducts formed between boron trifluoride and methyl alcohol has been accomplished.'05 In both adducts the OBF groups are auto-associated via a dipole-dipole interaction the 1:1complex being further associated through hydrogen-bonding.In the 1:2 complex the second molecule of methyl alcohol is bound to the first by a strong hydrogen bond. In the liquid phase both complexes undergo an ionic dissociation; one of the ions was established as being [BF,]- by Raman spectroscopy and some bands appeared to confirm the existence of protonated methanol MeOH,'. Boron trichloride is soluble in liquid hydrogen sulphide up to 0.3M existing in the form H,SBCI,; at higher concentrations the adduct precipitates out. However at about the melting point of -35 "C the adduct dissociates; in mixtures of BCl and H,S in a sealed tube under high pressure of hydrogen sulphide at 20 "C BC1,SH can be detected. Boron tribromide in concentrated H2S solutions up to 1M forms mainly BBr(SH) at -78°C; at 20°C the BBr(SH) is converted into (BBrS),.In the presence of NR,SH no thiohydrolysis of either boron trichloride or tribromide occurs at -78 "C; instead thioloborates NR,'[BX,SH]- are formed.lo6 Insertion of sulphur dioxide into the W-R bonds of [C,H,W(CO),R] (R = Me or CH,Ph) in liquid SO2 is markedly promoted by Lewis acids such as BF and SbF,; for example at -26 "C when R is Me the S02-BF3 insertion occurs 20 000 times faster than with sulphur dioxide alone. The promoted reaction proceeds to the corresponding Lewis acid-stabilized 0-sulphinato-complexes [C,H,W(CO)3{OS(OBF3)R}],which could be isolated and characterized as shown in Scheme 11.lo' Full details are now available for the copper-atom method of preparing diboron tetrachloride from BCl,.'08 The rotational barrier in gaseous diboron tetrabromide has been estimated as 3.07 kcal mol-' from an electron diffraction study.The molecule assumes a staggered equilibrium conformation with B-B and B-Br distances of 1.689 and 1.902 A respecti~ely.'~~" Addition of one mole of either diboron tetrafluoride or diboron tetrachloride to buta- 1,3-diene yields X,BCH,CH=CHCH,BX,; a further mole of diboron tetrachloride can be added to the butene double bond. However reaction of the tetrahalides with methyl- substituted conjugated or cumulated dienes leads to rapid polymerization of the lo4 J. Ape1 and J. Grobe Z. anorg. Chem. 1979 453 28 53. lo' J. Derouault T. Dziembowska and M.-T.Forel Spectrochim. Actu 1979 35A 773. Io6 G. Heller and W. Eysenbach Inorg. Chem. 1979,18 380. lo' R. G. Severson and A. Wojcicki J. Amer. Chem. SOC. 1973 101 877. 108 P. L. Timms Inorg. Synth. 1979 19 74. 109 (a) D. D. Danielson and K. Hedberg J. .Amer. Chem. Soc. 1979,101,3199; (b) W. Haubold and K. Stanzl J. Organometallic 0-em. 1979,174 141; (c) T. Davan and J. A. Morrison Inorg. Chem. 1979 18 3194. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway hydrocarbons rather than addition. lo9' Tetraboron tetrachloride B4C14 can be prepared at a rate of 3-5 mg h-' by passing a radiofrequency discharge through boron trichloride vapo~r.'~~~ Heterocydic Derivatives.-Five-membered heterocycles (21; X =S or NMe) are formed in good yield by the reaction shown.Attempted B-Cl substitutions using CH2CH2 I\ CI2BCH2CH2BCl2+X(SiMe,) -B 2C1SiMe3+ CIB ,BCl X (21) SbF3or Me4Sn result in ring cleavage. However the dimethyl derivatives (22) may be prepared by an extension of the above reaction."o I\ 2SnMe4 X(SiMe,), C12BCH2CH2BC12-ClMeBCH2CH2BClMe-CHZCHZ (22) Unsubstituted bis(borabenzene)iron [(C,H,BH),Fe] has been synthesized for the first time." la Molecular orbital calculations on bis(borabenzene) derivatives of the first-row transition metals show that the dominant bonding feature is the same as that in the metallocenes filled ligand el n-orbitals interact with the vacant metal d, and dYzorbitals. The borabenzene molecule shows intermediate bonding behaviour relative to the C,H and C6H6 ligands but is more closely akin to the former."'" The synthesis of cationic borabenzene complexes [ML(C,H,BPh) ]' where ML = CoC5H5 Co(C,H,BPh) RhC,Me, IrC,Me, or RuC6H6 has been described.The compounds are more electrophilic than the corresponding cyclopentadienyl complexes [ML(C,H,)]'; with nucleophiles three types of reaction were observed (i) nucleophilic addition at boron occurred to give stable adducts (ii) ring contraction produced C,H ligands and (iii) nucleophilic addition occurred at carbon if the nucleophile was H-(from NaBH,) to form complexes [ML(4-H-C,H,BPh)] [ML(6- H-C,H,BPh)] and [MLH(C,H,BPh)] as shown in Scheme 12 for example. Oxida- L L L L M+ M M MH 3-/$ c*ph --+ tr PhB'\ -,t MeCN --BPh + (+qh --4-H (12%) 6-H (30%) (51%) Scheme 12 tion of these latter compounds back to the borabenzene cationic complexes proved possible in some cases l2 FeCI [CO(~-HCSHSBP~)C~H~] [COCSHS(CSHSBP~)]+ Et2O-H20 'lo W.Haubold and U. Kraatz Chem. Ber. 1979,112 1083. (a) A. J. Ashe W. Butler and H. F. Sandford J. Arner. Chem. Soc.,1979,101,7066; (b) D. W. Clack and K. D. Warren Znorg. Chem. 1979,18,513. G. E. Herberich C. Engelke and W. Pahlmann Chem. Ber. 1979,112,607. The Typical Elements A number of boron-phosphorus heterocycles have been isolated e.g. (24)-(26). The heterocyclic ring in (26) has a chair configuration with a mirror plane through Hz Me,P /B\PMe2 Et,NBH,CI H2 / Me2P /B\pMe2 H2 BuLi -Me,P /"\PMe,'Br-Me2P I 1 MeLi Me3P /N\PMe2 H,C \B/cH2 II CH2 H2 the boron and nitrogen atoms.The P-N bonds are equidistant and prove the delocalized charge distribution in the cationic part of the ring which is supplemented by the negative boranate gr0~p.l'~ Treatment of the lithium reagent (23) with [(Me3P)2MC12](M = Ni Pd or Pt) gives the boranato-bis(dimethy1phosphonium methylide) complexes [M{(CH2PMe2)2BH2}2]. The nickel derivative has a centrosymmetric structure with a square-planar array of CH carbon atoms around the metal and a chair conformation for both six-membered rings.114 An electrochemical study of the triple-decker sandwich compounds (27) and (27a) shows that they are part of a five-membered electron-transfer series at least four members of which are stable e.g.'150 ? e (27)2'$(27)'+(27)0e(27)-=(27)2-Tetradecker sandwich compounds containing the ligand (28) have been made via the reaction^"'^ (M [(CO),Mn(28)]- +MC1 -B [(CO),Mn(28)M(28)Mn(CO)3]= Fej Co or Ni) [(28)Co( 2 8)]- + FeC12 + [(28)Co( 28)Fe( 2 8)Co( 2 8)] The diethyl ether and triethylamine adducts of 1-bora-adamantane react with a variety of amines to give the corresponding N-adducts.116 Hydroboration of 1,3,5,7-cyclo-octatetraene with monochloroborane-(dimethyl sulphide) followed by 'I3 H.Schmidbaur,H.-J. Fuller G. Muller and A. Frank Chem. Ber. 1979 112 1448. G. Muller U. Schubert 0.Orama and H. Schmidbaur Chem. Ber. 1979,112 3302. (a)D. E. Brennan and W. E. Geiger J. Amer. Chem. Soc. 1979 101 3399; (b) W. Siebert W.Rothermel C. Bohle C. Kruger and D. J. Brauer Angew. Chem.Internat. Edn. 1979,18,949. 11' B. M. Mikhailov V. N. Smirnov,0.D. Smirnova,V. A. Kasparov,N. A. Lagutkin,N. I. Mitin and M. M. Zubairov Khim.-Farm. Zhur. 1979,13,35;B. M. Mikhailov and T. K. Baryshnikova,Doklady Akad. Nauk S.S.S.R.,1978 243,929. F. A. Hart A. G.Massey P. G.Harrison and J. H.Holloway co co H/C-CH HB-CH --A / .-,\ HB<-;/BH HCq- -.BH Et Et BH BH co co Me-B\-,;B-Me Q 0 )+ S (27) (274 (28) thermal depolymerization of the product affords 2,6-dichloro-2,6-dibora-adaman-tane (29) in good yield. Methanolysis of the B-Cl groups in (29) gives the 2,6-dimethoxy-derivative which undergoes redistribution with H,BSMe in THF producing 2,6-dibora-adamantane in the form of its stable bis-(THF) adduct.’” A new heterocyclic system (30) has been prepared by reaction of diphenylboron bromide with di-isopropylcarbamoyl-lithium.l8 (Me,CH),N+ Phz-B,h Ph,BBr +LiCON(CHMe,) + + ,B-PhZ 0 H (30) Boron-Nitrogen Compounds.-The first B-perhalogenated di- and tri-borylamines have been synthesized using the reactions RN(SnMe,) +2BC13 + RN(BC13 +2Me3SnC1 R = SiC13 SiClzMe SiClMez or SiMe3 N(SnMe3) +3BC13 + N(BCl,) +3Me3SnC1 The water-clear liquid products are extremely sensitive to hydrolysis; N(BCl,) is remarkably stable thermally and can be recovered unchanged after being heated to 200 “C for two ho~rs.’” Schiff bases react with butyl-lithium under 1,2-addition and by following the reaction with the addition of R,BX the corresponding aminoboranes e.g.(31) can be obtained in good yield.’’’ Ph Ph R‘ Ph R’ C=NR’+BuLi+\ \CH-N / R2,BX ___* ‘CH-N / /H Bu/ ‘Li /Bu (31) \BR2 S. U. Kulkarni and H. C. Brown J. Org. Chem. 1979,44 1747. A.S.Fletcher W. E. Paget K. Smith K. Swaminathan J. H. Beynon R. P. Morgan M. Bozorgzadeh and M. J. Haley J.C.S. Chem. Comm. 1979,347. ’I9 T. Gasparis H.NBth and W. Storch Angew. Chem. Internat. Edn. 1979,18,326. A.Meller W. Maringgele and K. Hennemuth 2. anorg. Chem. 1979,449,77. The TypicalElements 41 Trimethylsilylacetamide and trimethylsilyltrifluoroacetamide give amidoboranes (32) on treatment with R,BX (X = C1 or Br).12' 0 0 II II Y,C-C-NHSiMe +R,BX -B Y3C-C-NHBR +Me,SiX (32) Similarly trimethylsilylsulphonamides form the sulphonamidoboranes (33).122a 11 B-"B N.m.r. coupling has been measured in tetrakis(dimethy1-amino)diborane(4). 122b Ph Ph PhS02N/ +R2BX -+ PhS0,N ' +Me3SiX \ 'SiMe BR2 (33) Ion cyclotron resonance studies show the proton affinity of borazine to be 196.4f02kcal mol-'. Calculations suggest that protonation occurs with little structural change relative to neutral borazine except for the geometry about the protonated nitrogen atom.'23 Macrocyclic and linear borazine-arene polymers [e.g. (34)] have been formed by reaction of 2,4-difunctional borazines with aromatic 1,3-dihydroxy- 2,3-diamino- or l-amino-3-hydroxy-compounds.'24 Me (34) (35) The electronic spectrum of 1,8,1079-triazaboradecalin(35) and the calculated charge distributions give evidence for considerable n-charge delocalization from N to B within the planar BN fragment; in the 0-system however the electron drift is in the opposite direction providing for a nett positive charge at the boron site.',' It is suggested from a study of their n.m.r.spectra that the five-membered B3N2 rings of (36) are planar; in contrast tetra-azadiboracyclohexane derivatives RB(NR-NR),BR (37) exhibit a twist conformation. One-electron oxidation of ''I W. Marringgele and A. Meller Monatsh. 1979 110 473. (a) W. Marringgele and A. Meller 2. Nafurforsch. 1979 34b 969; (b) F. Bachman H. Noth H. Pommerening B. Wrackmeyer and T. Wirthlin J. Magn. Resonance 1979 34 237. C. E. Doiron F. Grein T. B. McMahon and K. Vasudevan Canad.J. Chem. 1979 57 1751. 124 A. Meller H.-J. Fiillgrabe and C. D. Habben Chem. Ber. 1979,112 1252. 125 L. Komorowski J. Lipinski and K. Niedenzu 2.anorg. Chem. 1979 451 115. F. A. Hart A. G.Massey P.G.Harrison and J. H. Holloway R' B R2N-N' 'NR \I R] B-NR RR (37) these isomeric heterocycles using AlCl in dichloromethane yields the dark-blue thermodynamically favoured radical cation [RB(NR-NR),BR]'. 126n The N-N bond in N,N,N',N'-tetrakis-( 1,3-dimethyl- 1,3,2-diazaborolidinyl)hydrazine (38)is rather long at 1.464A. The compound is made by the reaction shown.'26b Li R Me \ / R/N-N\U Me N.m.r. parameters ('H "B I3C 31P) of several triazaphosphadiborines tri- azaphosphaborolidines and their phosphinylium cations have been measured.The geminal 31P-'3 C coupling constants are consistent with non-planarity of the ring systems this non-planarity being greater in the neutral than in the cationic species [e.g. (39)is the proposed structure of 2-chloro-1,3,4,5,6-pentamethyl-1,3,5,2,4,6-triazaphosphadiborine]. 27 CI I pc> Me Me (39) The 4,4-dichloro-4,2,6,1,3,5-boradiphosphatriazene (40)has been synthesized as shown. By substitution of the chlorine atoms in (40)a whole range of new compounds of this class is possible.12*" 12' (a) H. Noth W. Winterstein W. Kaim and H. Bock Chem. Ber. 1979,112,2494;(b) P. C.Bharara and H. Noth 2. Naturforsch. 1979,34b 1352. K. Barlos H. Noth B. Wrackmeyer and W. McFarlane J.C.S. Dalton 1979 801. (a) H.Binder and J.Palmtag 2.Naturforsch. 1979,34b 179; (b) H.Fusstetter and H. Noth Chem. Ber. 1979 112 3672. The Typical Elements 43 Tin dichloride and LiNSiMe,(BMe,) react to give a dimeric diazastannaboretidine (41) which has a tricyclic tub-shaped structure built up from three fused four- membered rings 1286 Me3 Si Me,SiN-Sn-N -BMe SnCI + Me,Si -N-BMe -* I I I I +BMe3 I Li MeB-N-Sn-NSiMe Si Me3 Berates.-The Raman spectra of borates in aqueous solution have been recorded over a wide range of pH. The monomers B(OH) and [B(OH),]- were observed and three other species detected which were thought to be the polyborates [B,O,(OH),]- [B405(OH)4]2- and [B303(OH),]-. 129 Triclinic lithium cadmium borate LiCdBO, contains discrete BO triangles in which the average B-0 distance is 1.386 A.130Europium(I1) metaborate EuB,O, has a structural frame- work consisting of endless chains of BO groups (BO,), along the c-axis.The B-0 distances are 1.32 1.41 and 1.39 A the short bond involving the unshared oxygen atom in the (BO,) chain. EuB,O, which is isostructural to CaB,O, is an antiferrornagnet with a Ntel temperature TN, of 3 K.l3In EuB,O is thought to have a three-dimensional structure made up of BO tetrahedra and Eu2B,0S iso- structural with the strontium salt has isolated [B2OSl4- ions. 131b Single crystals of sodium pyroborate Na,B,O, have been obtained for the first time. The structure contains isolated 02BOB02 groups which have a BOB angle of 120.6°.'32" Cadmium pyroborate also has isolated [B2O5I4- The basic structural unit in Na,B,,O,,(OH) is the polyanion [B12020(OH)4]8- the structure of which can be described as a loop of six six-membered B-0 rings built up from six BO tetrahedra four B02(OH) triangles and two BO triangles.The six tetrahedra are linked to each other by corner-sharing to give a 12-membered B-0 ring; each tetrahedron also shares two corners with triangles located on the external side of the 12-membered ring.132c The very unstable trisilyl borate has been prepared by the reaction 3H3SiBr + (Bu3Sn0),B -B (H3Si0)3B+ 3SnBu3Br Decomposition produces hydrogen monosilane and disiloxane. 133 lZ9 M. Maeda J. Znorg. Nuclear Chern. 1979.41 1217; see also R. Janda and G. Heller 2.Nafurforsch. 1979,34b 585 1078.130 E. V. Sokolova V. A. Boronikhin M. A. Simonov and N. V. Belov Doklady Akad. Nauk S.S.S.R. 1979,246 1126. 13' (a)K. Machida G.Adachi and J. Shiokawa Acta Crysr. 1979 B35,149; (b)K. Machida,H. Hata K. Okuno G. Adachi and J. Shiokawa J. Znorg. Nuclear Chem. 1979,41 1425. 13' (a) H. Konig R. Hoppe and M. Jansen 2.anorg. Chern. 1979,449 91; (b) E. V. Sokolova M. A. Simonov and N. V. Belov Doklady Akad. Nauk S.S.S.R.,1979,247 603; (c) S. Menchetti and C. Sabelli Acta Cryst. 1979 B35,2488. 133 W. Bett and S. Cradock. J. Chern. Res. (S) 1979 33. 44 F. A. Hart A. G.Massey P. G.Harrison andJ. H. Holloway Hydroboration.-The hydroboration reaction has been the subject of another theoretical The recently discovered ClBH -SMe hydroborates alkenes rapidly and quantitatively at 25 "C; a simple low-pressure distillation is sufficient to give the pure R,BCl.When BrBH2 -SMe is used pure R,BBr is obtaiped only with hindered alkyl groups; in other cases the R,BBr -SMe complexes are formed.'34b Internal alkynes are readily converted into the B-vinyl derivatives in yields of 90-96% by treatment at 0 "C in THF with an equivalent quantity of 9-borabicy- clo[3,3 llnonane 9-BBN. However under these conditions simple terminal alk- ynes such as dec- 1-yne undergo significant dihydroboration; fortunately this difficulty can be overcome by the use of an excess of the terminal a1k~ne.l~~ The exceptional sensitivity toward structure exhibited by 9-BBN in the hydroboration of simple olefins conjugated and non-conjugated dienes and acetylenes carries over to the hydroboration of allenes.With only a few exceptions 9-BBN attacks at the end carbons of allenes to give B-allyl-9-BBN. Hydroboration of an unsymmetrical allene could theoretically lead to two allylboranes but it is found that only the one with boron bound to the less-substituted position is Although hy- droboration of allynes with 9-BBN is surprisingly sluggish unhindered olefins react rapidly with 9-BBN. This can be used to form acetylenic organoboranes by selective hydroboration of R' CE CCH2CR2=CH2. 37 A number of facile substitution and exchange reactions of 9-BBN and its B- substituted derivatives have been described. For example halogens and hydrogen halides react with 9-BBN to give B-halogeno-9-BBN (Cl Br or I)which can also be made by redistribution between the respective boron trihalide and 9-BBN or B-OMe-9-BBN; alcoholysis of 9-BBN or B-halogeno-9-BBN produces high yields of B-OR-9-BBN.'" Another route to B- halogeno-9-BBN involves hydroboration of cyclo-octa- 1,Sdiene with the dimethyl sulphide complexes of halogenoboranes H,BX -SMe (X = C1 Br or I) when a mixture of B-X-9-BBN and its [4,2,1]-isomer results; the latter thermodynamically less stable isomer predominates but can be readily converted into B-X-9-BBN by gentle heating.Distillation following addi- tion of one equivalent of the respective BX provides B-X-9-BBN free from Me$. 139a The ready olefin-alkyl exchange noted when B-alkyl-9-BBN derivatives are refluxed with olefins in THF is explained in terms of a dehydroboration-hydroboration process.139b Pyridinium chlorochromate oxidizes organoboranes containing primary alkyl groups to the corresponding aldehydes so that a one-pot synthesis of aldehydes from terminal alkenes is now p~ssible.'~~' Boron-Sulphur Compounds.-Reaction of trime thy1 thioborate B (SMe) with tri-isothiocyanatoboron B(NCS), at room temperature gives mixtures containing .I" (a) K. R. Sundberg G.D. Graham and W. N. Lipscomb J. Amer. Chem. SOC.,1979,101,2863; (b) H. C. Brown N. Ravindran and S. U. Kulkami J. Org. Chem. 1979 44 2417. 135 H. C. Brown C. G. Scouten and R. Liotta J. Amer. Chem. Soc. 1979 101 96. 13' H. C. Brown R. Liotta and G. W. Kramer J. Amer. Chem. SOC.,1979 101 2966.13' C. A. Brown and R. A. Coleman J. Org. Chem. 1979 44 2328. 13' H. C. Brown and S. U. Kulkami J. Organometallic Chem. 1979 168 281. 139 (a) H. C.Brown and S. U. Kulkarni J. Org. Chem.,1979,44,2422;(b) M. M. Midland J. E. Petre and S. A. Zderic J. Organometallic Chem. 1979,182 C53;(c) C. G. Rao S. U. Kulkami and H. C. Brown J. Organometallic Chem. 1979 172 C20. The Typical Elements 45 B(SMe), the mixed compounds B(NCS)(SMe) and B(NCS),SMe in low concen- tration and association compounds; the various components could not be isolated owing to rapid equilibria being set up. The association compounds are thought to have structures involving S-B donor-acceptor bonds between monomers for example [B(NCS),SMe] and [B(NCS),SMe],[B(NCS)3]; treatment of these compounds with trimethylamine yields Me,NB(NCS) and Me,NB(NCS),SMe.'40 Substitution exchange between trithiadiborolans has been shown to occur by exchange of both the substituent and the boron atom to which the substituent is bound (Scheme 13).This result was explained by a mechanism involving a con- Is-s ?-? XB ,BX + Y'OB '$BY 2Yl0B ,BX S S S Scheme 13 formationally flexible ten-membered ring as an intermediate. This type of exchange also occurs between identical trithiadiborolans (i.e. X = Y).I4' Selected Organometallic Topics.-Triphenylboron and [Et,N]'[(C,H,)Fe(CO),]- react to give a 1 1 adduct [Et4N]'[Ph,BFe(CO),(C5H,)]-(42) for which spectral data strongly indicate a Fe-to-B bond and suggest that the negative charge is localized on the boron atom.In dilute solution (42) spontaneously converts via migration of the BPh3 group into [NEt4]'[Ph3BCsH4Fe2(C0)4(C5H,)I-and [NEt,]'[BPh,H]-. The former anion has a central di-p-carbonyl-di-iron unit (Fe-Fe = 2.540 %.)with a terminal carbonyl and a cyclopentadienyl ligand on each iron; the configuration of the rings is cis. The nearly tetrahedral Ph,B group is q '-bonded to one of the cyclopentadienyl rings at the position furthermost from the other ring; i.r. spectra indicate that a cis-trans equilibrium exists in solution as in the case of the similar [C5H,Fe(C0)2],.'42 A variety of cyclopentadienyl- and pentamethylcyclopentadienyl-boranes have been prepared via the reactions shown in Scheme 14. The compounds have a fluxional structure owing to sigmatropic rearrangements of the boryl groups the speed of these rearrangements depending on the Lewis acidity of the boron atom.143 Bis-vinyl boron derivatives (43) are formed when a similar reaction is attempted between two moles of boron trihalide and 1,l-bis(trimethylsilyl)cyclopentadiene.'44 Treatment of ferrocenyl-lithium FcLi with a deficiency of boron trifluoride gives red Fc3B and black crystals of Fc4B.This consists of three ferrocenyl(I1) and one ferricenyl(II1) moieties covalently attached to a quadrivalent boron atom and can be formally described as a zwitterion ferricenyl(II1) tris[ferrocenyl(r~)]borate. In support of this formation it is found that three centroid-to-centroid distances range from 3.291 to 3.320%.,but the fourth is 3.428%.;in several ferricinium salts 140 H.-R.Archekzai H. Mongeot J. Dazord and J.-P. Tuchagues Canad. J. Chem. 1979,57 1122. 14' H.Noth and T. Taeger 2.Natutforsch. 1979,34b 135. J. M. Burlitch J. H. Burk M. E. Leonowin and R. E. Hughes Znorg. Chem. 1979,18,1702. 143 P. Jutzi and A. Seufert Chem. Ber. 1979,112,2481; J. Organometallic Chem. 1979,169 327 373. 144 P. Jutzi and A. Seufert J. Organometaliic Chem. 1979 169 357. 14' F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway 0+ BX -oBx2 SiMe, oBx2 + TiC1 + Q~3x2 TiCI D = NMe3or py Me Me s/' + BX -MeWBL2 HNMe Me 1 Me B(NMe2), Me Me Me : WiMe, Me Scheme 14 centroid-to-centroid distances are found to expand to ca. 3.4 A.The complex has an intervalence electronic transition near to 2200 nm.145a The 13C and "B n.m.r. spectra of 29 phenylboranes and nine boron-substituted aromatic heterocycles have been recorded and discussed. The observed 13Cshifts of the para carbon atoms are consistent with significant interaction between the boryl groups and the aromatic When boron trifluoride reacts with Me3SnCF3 in a 1 3 ratio the ion [(CF,),BF,]- is formed together with the known [CF3BF3]-.'45' 2 Aluminium In the purple complex formed between aluminium atoms and benzene in a neon matrix the metal atom is thought to be co-ordinated to only one C-C bond the co-ordination plane CAlC being perpendicular to the benzene ring.146 (a) D. 0.Cowan P. Shu F. L. Hedberg M. Rossi and T. J. Kistenmacher J. Amer.Chem.SOC.,1979 101 1304; (b) J. D.Odom T. F. Moore R. Goetze H. Noth and B. Wrackmeyer J. Orgunometalfic Chem. 1979,173,15;(c)G.Pawelke F. Heyder and H. Burger,J. Orgunometullic Chem. 1979,178,l. P.H.Kasai and D. McLeod J. Amer. Chem. SOC.,1979,101,5860. 14' 14' The Typical Elements 47 Differential thermal analysis of y-AlH, prepared by AlCI + 3LiA1H4 Et 0 3LiClJ+ 4AlH3 showed an exothermic effect due to transformation to a-AlH followed by an endotherm for the decomposition of a-A1H3. 14' Alane in THF reduces some of the carbon monoxide groups of metal hexacarbonyls selectively (95%) to ethylene; the total amounts of CO reduced were Cr (17%) Mo (4%) and W (6%)using a six-fold excess of alane. When the reduction was carried out with AlD only C,D was formed.No inorganic compound could be isolated so the fate of the remaining carbon monoxide is not known. A complex mixture of hydrocarbons was obtained from the reduction of [RU,(CO)~~] and further gas evolution occurred on addition of acid to the final residue.148 The photolytic decomposition of lithium tetrahydroaluminate powder has been Optimum conditions for the preparation of NaAlH from sodium hydride and aluminium trichloride in THFhave been established. Careful hydrolysis at -70 "Cusing a deficiency of water allows isolation of NaAIH,0H.150 The [AlH,]- ion in NaAlH has a compressed tetrahedral geometry with Al-H = 1.532 A and unique angles of 113.9' and 107.3'; the sodium atom has eight nearest-neighbour hydrogens which define the vertices of a distorted triangular dodecahedron.151 Pure solvent-free magnesium tetrahydroaluminate can be produced by the reaction sequence THF 12 h; 100°C NaAlH + MgC12 -+ Mg(A1H4)2m4THF -Mg(A1H4)2 mm Decomposition to MgH2 Al and H2 occurs at 130-1 35 'C and is followed at 3 10 "C by dissociation of the magnesium hydride.152 Trends in structure and vibrational frequencies of gaseous MX and MX species at high temperature have been noted and estimates given for v1of AlF and GaF,.'53 1.r. spectra of A1Cl2Br AlClBr, and AlBr held in a solid argon matrix imply a planar DJhstructure for each of the trihalide~.'~~ In solid ammonia-aluminium trichloride H3NA1Cl3 the aluminium atom has a slightly distorted tetrahedral co-ordination with A1-N = 1.921 8 and Al-Cl(average) = 2.1 1 A.The structure is the same as that in the gas From a study of both the mass spectra and the gas-phase structures determined by electron diffraction it is concluded that in the ammonia complexes MX3 -NH3 AIBr3 is a stronger acceptor than AlCI and that the co-ordinate bond is stronger in the aluminium complexes than in those of gallium. k considerable opening up of the HNH angles on complexation was 0bser~ed.l~~ 14' P.Claudy B. Bonnetot and J. M. Letoffe J. Therm. Analysis 1979 15 129. 148 C. Masters C. van der Woude and J. A. van Doorn J. Amer. Chern. SOC. 1979,101 1633. 149 P. J. Herley and D. H. Spencer J. Phys. Gem. 1979,83 1701. I5O V. V. Gavrilenko M. I. Vinnikova and L. I. Zakharkin Zhur. obshchei Khim.1979,49,982. lJ1 J. W. Lauher D. Dougherty and P. J. Herley Acta Cryst. 1979 B35,1454. 152 P. Claudy B. Bonnetot and J. M. Letoffe J. Therm.Analysis 1979 15 119. 153 M. C. Drake and G. M. Rosenblatt J. Electrochem.Soc.,1979,126,1387. 154 R. G. S. Pong A. E. Shirk and J. S. Shirk J. Gem. Phys. 1979,71 525. 155 K. N. Semenenko E. B. Lobkovskii V. B. Polyakova I. I. Korobov and 0.V. Kravonenko Koord. Khim. 1978,4 1649. 156 M. Hargittai J. James M. Bihari and I. Hargittai Acta Chim. Acad. Sci. Hung. 1979,99 127. 48 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Aluminium tribromide when added to [Mn(CO),Me] or [C,H,Mo(CO),Me] in toluene catalyses the insertion of CO into the metal-methyl bond by forming the stable complexes (44) and (46).Both these complexes react smoothly with carbon monoxide at atmospheric pressure to give the acyls (45) and (47). Free acyl (47) is [Mn(CO),Me]+ AlBr3 --* (C0)4Mn-CMe 9(CO),MnCMe 1 v Br A1,o 8 AIBr Br2 (44) (45) (CO), [C5H5Mo(CO),Me]+AIBr + C,H,Mo-CMe 2 C,H5(C0)3MoCMe 1 \\ 11 Br\ A1/O 0 AlBr Br unstable with respect to CO loss and is difficult or impossible to make by high- pressure CO insertion into [C,H,Mo(CO),Me]. Thus Lewis acids may be used to stabilize otherwise unstable metal acyl~.'~~~ Aluminium trihalides add to the iron atom of polyolefiniron tricarbonyl complexes not to the carbonyl oxygens. X-Ray data of aqueous solutions of aluminium trichloride have been interpreted using a model in which the chloride ions have a co-ordination number of six and the [A1(H20)6I3+ cations interact with twelve water molecules through short and linear hydrogen bonds the water molecules nearest the aluminium having trigonal orien- tation.'*' A I9F and 27Al n.m.r.study of aqueous solutions containing aluminium chloride or nitrate and either ammonium or hydrogen fluoride at F :A1 ratios s 4 showed the presence of [!~l(H,o)~]~+ and the fluoro-complexes [A1F4-,]('-")-.aq. (n = 0-3).15' The decomposition of solid aluminium trichloride hexahydrate into aluminium oxide takes place via the formation of an intermediate basic aluminium chloride.16' Caesium tetrafluoroaluminate prepared from CsF and AlF, is isostructural to CsCrF4 the AlF6 octahedra present having an average A1-F distance of 1.83 A.161 Potassium hexafluorosilicate reacts with aluminium oxide at temperatures between 500 and 700 "C to give K3A1F6 KAIF4 and KA1SiO4; only K,AlF6 is formed below 600 "C.The difference in reactivity of a-and y-A1203consists in the formation of =IF4 at 650 and 600 "C respectively.'62 A comparison has been made of the crystal structures of alkaline (Li-Cs) and pseudo-alkaline (NO NH,) tetrachloroaluminates. 163a From these structures it has (a) S. B. Butts E. M. Holt S. H. Strauss N. W. Alcock R. E. Stimson and D. F. Shriver,J. Amer. Chem. Soc. 1979,101,5864;(6) B. F.G. Johnson K. D. Karlin and J. Lewis J. Organometallic Chem. 1979 174,C29. 158 R. Caminiti G. Licheri G. Piccaluga and G. Pinna J. Chem. Phys. 1979,71 2473.Y. A. Buslaev and S. P. Petrosyants Koord. Khim. 1979,5 163. 160 R.Naumann D. Petzold F. Paulik and J. Paulik J. Therm. Analysis 1979 15,47. R.Usch and Ch. Hebecker 2. Nutgrforsch. 1979 34b 131. 162 L.Kolditz and U. Thielsch 2. Chem. 1979 19 229. 163 (a) G. Mairesse P. Barbier and J. P. Wignacourt Acta Cryst. 1979,B35,1573;(b) H. D.B. Jenkins K. F. Pratt G. Mairesse P. Barbier and J. P. Wignawurt Znorg. Chem. 1979,18 2796. The Typical Elements 49 been possible both to compute lattice energies for the alkaline and ammonium tetrachloroaluminates and to estimate a value of -1 188f15kJ mol-' for AH,"[A1Cl,(g)].'63b The values of AS" and AH" for the dissolution of potassium chloride in molten KAlC1 are 46.8 J K-' mol-' and 19.7 kJ mol-' respectively.The possible presence of [Al,Cl,,]-ions in these solutions was Poten-tiometric and Raman spectral studies of magnesium(I1) dissolved in KCl-AlCl melts suggest the ocurrence of the equilibrium [MgC14]'-$ [MgClJ + C1-In an acid melt (pC1- = 5.98) the Mg2+ ion is thought to exist perhaps solvated with [AlCl,]-or [A1,C17]-. 165 Phase diagrams of the MCl-AlCl,-l.SO systems (M = Li Na K or NH,) between -30 and +50 "C indicate the presence of solid compounds of the type MAlC1 -nSO (M = Li or Na n = 1.5 or 3; M = NH, n = 5). Liquid phases can be obtained at room temperature and atmospheric pressure in the lithium chloride and sodium chloride sys tems. 166 No evidence could be obtained for interaction between stannous chloride and MAlC1 (M = Li Na or Cs) over the whole composition range from pure SnC1 to pure MAlCl,.However dissociation of SnC1 polymers possibly into the monomer was detected. Four Raman spectral peaks in the 50% SnCl -CsC1-50% CsAlCl melt were assigned as fundamentals of the pyramidal complex ion [SnCl,]-.'67 Direct chlorination of sulphur in the presence of aluminium trichloride allows the stabilization of S'" as [SCl,]+[AlCl,]-. Unlike SCl, this extremely hygroscopic salt is thermally stable at room temperature.I6' In basic (i.e. chloride-rich) chloroaluminate melts nickel(I1) is present as [NiCl,]'-.'"'" Raman spectroscopy has provided the first direct evidence that zirconium tetrachloride forms a complex ZrC1 -2AlC13 with AlCl in both the liquid and vapour phases. The data are consistent with a structure in which the zirconium is in a six-co-ordination site with two bidentate AlCl groups; both cis-and trans-isomers may be present.Above 300 "C the complex dissociates back into the starting Solid samarium trichloride forms SmAl,Cl, when heated with gaseous aluminium trichloride. A nine-co-ordinate structure is suggested for the samarium formed by three triply bridging AlCl groups. At 650 K the volatility enhancement of Sm'l by AlC1 is estimated17' as about lo1'. The binary TaC1,-AlCI system at cu. 200 "C contains only non-interacting Ta,Cl, and Al,C16 molecules. The complexes formed when TaC1 is dissolved in AlC1,-NaC1 or AlC1,-KCI melts depend on the acidity and temperature of the melt [TaCl6]-(Oh) is present only in basic to slightly acid melts; TaCI (D3,Jis mainly stable in neutral and acidic melts at high temperature; Ta,Cl, is formed only in acidic melts at lower temperatures 164 P.B. Brekke J. H. von Barner and N. J. Bjerrum Inorg. Chem. 1979,18 1372. 16' M. M. Laursen and J. H. von Barner J. Inorg. Nuclear Chem. 1979,41 185. H. Kuhnl A. Strumpf and M. Gladziwa 2. anorg. Chem. 1979,449 145. 167 T. Kirkt,ud P. Klaeboe and H. A. 0ye J. Inorg. Nuclear Chem. 1979,41 189. 168 G. Mamatov R. Marassi F. W. Poulsen S. E. Springer,J. P. Wiaux R. Huglen and N. R. Smyrl,J. Inorg. Nuclear Gem. 1979 41 260. 16' (a) R. J. Gale B. Gilbert and R. A. Osteryoung Inorg. Chem. 1979,18,2723; (b) D. R. Taylor and E. M. Larsen J. Znorg. Nuclear Chem. 1979,41 481. I7O G. N.Papatheodorou and G.H. Kucera Znorg. Chem. 1979,18,385. 50 F.A. Hart A. G. Massey P. G. Harrison and J. H.Holloway (< 1800C).171 Uranium dioxide is chlorinated to UCl by aluminium trichloride at about 300 K; in the presence of free chlorine uranium pentachloride is formed which complexes with the aluminium chloride to give the gaseous species UAlCl,. Not only does the formation of UAlC18 enhance the volatility of UCl,(s) but it also increases the stability of the quinquevalent A study of the CoI,(s) + A1216(g) system has shown that the gaseous complex CoA1218 is formed exclusively at the expense of COA~I,.'~~ Aluminium trichloride like GaCl and InCl, yields an electrically conducting solution in acetonitrile. Quantitative Raman and 27Al n.m.r. spectroscopy both show that approximately 70% of the aluminium is in the form of[AlCl,]-; the adduct 'AlCl -2MeCN' crystallizing from such solutions has the composition [AlCl -5MeCN]2'[A1C1,]- -MeCN.From this and other evidence it is concluded that [AlCl 5MeCNI" is the major cationic species formed. Five sharp 27Al n.m.r. peaks are observed when Al(ClO,) dissolves in acetonitrile demonstrating that the perchlorate ion is interacting strongly with the A13' ions."' Electrolysis of aromatic hydrocarbons dissolved in the aluminium trichloride-n- butylpyridinium chloride melt (liquid at room temperature) produced radical cations which were significantly more stable in this medium than in the more usual solvent Potentiometric meas~rernents'~~ a~etonitri1e.l~~ and Raman show that no free AlCl is present in the 1:1and 2 :1melts.Addition of benzene to the AlX,-R-pyridinium X melts (X = C1 or Br R = Et or Bun) decreased the dielectric constant causing ion-pair formation. No evidence was for the formation in these melts of the previously described u-complex between aluminium trichloride and benzene. A single A1-Br-A1 bridged structure is proposed for Al,Br6 complexed to aromatic hydrocarbons such as toluene and o-x~lene.'~~ Until now the primary acidic systems that have been used to stabilize high concentrations of alkyl cations have contained antimony pentafluoride. However solutions of aluminium tribromide and gallium trichloride in S0,FCl or halo- genoalkanes also stabilize the same cations derived from C to C alkyl halides as occur in SbF ~ystems.'~~-'~' In the presence of aluminium tribromide the cations are present as R'[A1,Br6X]- whereas gallium trichloride forms both R'[Ga,X,]- and R'[GaX,]- salts.180 Although the t-Bu' cation can be formed in the reaction of t-butyl chloride with either aluminium or gallium trichloride in liquid hydrogen chloride and when t-butyl bromide dissolves in A1,Br6-1.HBr mixtures no forma- tion of CMe,' occurs in the systems BC13-HC1 InCl,-HCl and BBr,-HBr.The t-amyl cation is stabilized only in the Al2Br6-1.HBr solvent system but iso-Pr+ is unstable in all the above mixtures.182 17' R. Huglen F. W. Poulsen G. Mamantov and G. M. Begun Znorg. Chem. 1979 18 2551. G. N. Papatheodorou and D. A. Buttry Znorg. Nuclear Chem. Letters 1979,15,51.B. Stelthove and H. Schafer 2. anorg. Chem. 1979,451 25. 174 J. Robinson and R. A. Osteryoung J. Amer. Chem. SOC.,1979 101 323. 17' R. J. Gale and R. A. Osteryoung Znorg. Chem. 1979 18 1603. 176 J. Robinson R. C. Bugle H. L. Chum D. Koran and R. A. Osteryoung J. Amer. Chem. SOC.,1979,101 3776. 177 J. Robinson and R. A. Osteryoung J. Amer. Chem. SOC.1979 101 321. ''* R.Schiirmann and H.-H. Perkampus Spectrochim. Acta 1979,35A,45. G. M. Kramer J. Org. Chem. 1979 44 2616. D.Mirda D.Rapp and G. M. Kramer J. Org. Chem. 1979,44,2619. P.Briiggeller and E. Mayer 2. Nuhtrforsch. 1979 34b 891. F.Kalchschmid and E. Mayer 2. Nahtrforsch. 1979 34b 548. The Typical Elements 51 Dimethylbromonium and dimethyliodonium ions are formed at -40 and -12 "C respectively in liquid methyl bromide and methyl iodide saturated with aluminium tribromide.The concentration of halonium ions decreases rapidly with increasing temperature such that no Me,Br' can be detected at room temperat~re.'"~ A molecular orbital study of the stereochemical requirements of the five-co- ordinate aluminium atom in [A1(OH),]2- shows that the trigonal bipyramid is the most stable arrangement.Is4 Electron diffraction measurements are consistent with a D model for tris-( 1,1,1,5,5,5-hexafluoroacetylacetonato)aluminiumin the gas phase the oxygen atoms of the three ligands being arranged round the aluminium in a slightly distorted octahedral fashion angle OAlO = 87.2" and A1-0 = 1.89344.'"' Tetrameric aluminium tri-isopropoxide has a structure composed of a central octahedrally co-ordinated aluminium atom connected by six bridging isopropoxy- groups to three tetrahedral Al(OPr') groups.186 The chloro-isopropoxide A1,C1,(OPri) is formulated as C1Al[(Pri0)2AlCl,] with all the isopropoxy-groups bridging.a-AlCl(OPr') has a trimeric structure in which four of the six isopropoxy- groups are bridging and the other two are terminal on different aluminium atoms; P-AIC1(OPri) is p01ymeric.~~' The electronic spectra of the green double-alkoxides Ni[Al(OR),] (R = Me Et Pr" or Bu") are interpreted in terms of a structure based on a Ni(OR) octahedron sharing faces with two Al(OR) tetrahedra. The cobalt(I1) and copper(I1) derivatives were assumed to have distorted octahedral co-ordination about the central metal atom.The OR- group fits into both the spectrochemical and nephelauxetic series at a position close to that of water.'" A careful study has been made of three different methods for the preparation of a-A12S3. The volume expansion associated with the 7-A12S3 + a-Al,S3 transition which occurs on cooling caused rupture of the apparatus when growth of single crystals was attempted. 189a Aluminium is tetrahedrally co-ordinated by sulphur atoms in A11nS3.'s9b The structure of acid aluminium phosphate the phase A1203 * 2P,05 -9H20 consists of two different structural units isolated PO tetrahedra and larger aggregates formed from two A106 octahedra connected by three PO tetrahedra by common vertices. The structural formula is thus given by [Al~(H1+xP04)~(H20)~H3-3xP04], the factor x showing the presence of proton disorder in the crystal.190 The double perchlorates MAl(ClO,) HC10 (M = Rb Cs or NH,) and Cs,Al(ClO,) * HClO, made by reaction of aluminium trichloride with perchloric acid in the presence of MClO, are stable at room temperature but lose perchloric acid at 50-70 "C in a vacuum. The acid is thought to be hydrogen bonded to the [Al(ClO,),]-or [Al(C10,)5]2- anions.191 The iodates M(I03) -nH,O for M = P. Briiggeller and E. Mayer Z. Naturforsch. 1979 34b 896. In4R. J. Hill G. V. Gibbs and R. C. Peterson Austral. J. Chem. 1979 32 231. Is' M. L. Morris and R. L. Hilderbrandt J. Mof. Structure 1979 53 69. 186 N. Y. Turova V. A. Kozunov A. I. Yanovskii N. G. Bokii Yu.T. Struchkov and B. L. Tarnopol'skii J. Inorg. Nuclear Chem. 1979,41 5. lS7 V. A. Kuzunov N. I. Kozlova N. Y. Turova and Y. S. Nekrasov Zhur. neorg. Khim. 1979,24 1526. lS8 E. Stumpp and U. Hillebrand Z. Naturforsch. 1979,34b 262. Is' (a) E. E. Hellstrom and R. A. Huggins Materials Res. Buff.,1979,14,127;(b) M. Schulte-Kellinghaus and V. Kramer Acta Cryst. 1979 B35 3016. 190 R. Kniep and A. Wilms Z. Naturforsch.,1979,34b 750. 191 Z. K. Nikitina and V. Ya. Rosolovskii Zhur. neorg. Khim. 1979 24,930. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway A1 (n = 9),Ga (n= 2) In (n= l) or T1 (n = 2) may be prepared by mixing the nitrates with iodic acid solutions in a 1:3 mole ratio.Ig2 All the methyl groups in solid trimethylaluminium dimer rotate about their triad axes at 77 K which supports the two-electron three-centre AICAl-bond model for the bridging methyl groups.The activation energy for the rotation193 is only 0.84kcal mol-l. Reaction of ferrocenylmercuric chloride with trimethylaluminium in toluene at 60 "C gives [q5-C,H,Fe][qS-C,H,A12Me4Cl] in which the two alu- minium atoms are bridged by both a chlorine atom and one carbon of the C5H4 ring (48). On the 'H n.m.r. time-scale the methyl groups are equivalent at room temperature but at -40 "C the expected two CH peaks in 1:1 ratio can be observed. 194n (48) (Reproduced by permission from Inorg. Chern. 1979,18 279) An X-ray structure has confirmed that in K[Al,Me,SCN] the thiocyanate group acts as an S,N bridging ligand.The Al-N bond length is normal (1.951 A) but the bond between A1 and S is somewhat longer (2.489A) than expected suggestive of a rather weak interaction. 194b Thermolysis of Me4N[Et,A1C1A1Et,] is not as straight- forward as first thought. In addition to the previously reported products ClAlEt and A12Et6 Me,NAlEt is formed simultaneously in lesser amounts. A mechanism involving the formation of methyl chloride as a transient species which undergoes further reaction with A12Et6 ultimately to produce CH and C2H4 is given.194c In [Et{o-C6H4CH(Me)CH,}AI] the two hydrocarbon residues o-C,H,CH(Me)CH act as chelating ligands both bonding to an aluminium atom via an aromatic and an aliphatic carbon atom; the aromatic carbons also participate in two 192 B.N. Ivanov-Emin V. I. Rybina B. E. Zaitsev T. V. Ustyuzhenskaya and G. 2.Kaziev Koord. Khim. 1979 5 515. 193 S. Albert and J. A. Ripmeester J. Chem. Phys. 1979 70,722. 194 (a)R. D. Rogers W. J. Cook and J. L. Atwood Inorg. Chem. 1979 18 279; (b) R. Shakir M. J. Zaworotko and J. L. Atwood J. Organometallic Chem. 1979,171,9;(c) J. E. Bozik,D. L. Beach and J. J. Harrison J. Organometallic Gem. 1979 179 367. The Typical Elements (49) (Reproduced by permission from 2.Naturforsch. 1979 34b 1293) AlCAl bridges (49).19' Co-ordination of the triphenyls of Al Ga and In to a number of transition-metal carbonylate anions has been achieved. Typical of the solid complexes tetraethylammonium triphenyl(75-cyclopentadienyldicarbonyliron) aluminate(Fe-A/) has a direct metal-metal bond of length 2.510 A; an exception is Bu",N[C,H,W(CO),(AlPh,)l in which the aluminium is co-ordinated to a carbonyl oxygen atom.196 Organo-aluminium dichlorides can be prepared by stereospecific transmetallation reactions between aluminium trichloride and compounds formed by hydrozirconation of olefins and alkynes with [(C,H,),Zr(H)C1].'97 The 1:1monomethylamine adduct of trimethylaluminium decomposes at 215 "C with loss of methane and the formation of (MeAlNMe) as well as the known (MeAlNMe),.An intermediate in this decomposition isolated from reactions at lower temperatures is (Me,AlNHMe),(MeAINMe),. This compound has a struc- ture based on aluminium-nitrogen cages in which both the A1 and the N are tetrahedrally co-ordinated and from which the methyl groups point outwards (50).The gallium derivative has the same A kinetic study has shown that the elimination of hydrogen between N-methylaniline and dimethylaluminium hydride is not a reaction of the preformed 1:1 adduct; in fact adduct formation is a 'dead-end' path for the elimination process. 19*' Etherates of organo-aluminium compounds have been '95 D. J. Brauer and C. Kriiger 2.Naturforsch. 1979 34b,1293. '96 J. M. Burlitch M. E. Leonowicz R. B. Petersen and R. E. Hughes Znorg. Chem. 1979 18 1097. '97 D. B. Carr and J. Schwartz J. Amer. Chem. SOC. 1979,101,3521. 19* (a) S. Amirkhalil P. B. Hitchcock and J. D. Smith J.C.S. Dalton 1979,1206; (b) 0.T. Beachley and C. Tessier-Youngs Znorg. Chem. 1979,18,3188; (c) V.P. Mardykin P.N. Gaponik and A. F. Popov Russ. Chem. Rev. 1979 48 487; (d) F. Gerstner W. Schwarz H. D. Hausen and J. Weidlein 1. Organometallic Chem. 1979,175 33; (e) E. Niecke and R. Kroher 2.Naturforsch. 1979,34b 837. F.A. Hart A. G.Massey P. G.Harrison and J. H. Holloway (50) (Reproduced from J.C.S. Dufton 1979 1206) Tetramethyloxamide reacts with the trimethyls of Al Ga and In to give monomeric bisdimethylmetaloxamidines (51)which have a planar structure based on two fused five-membered rings:198d Me Me Me2M(Nx>MMe2 N--Me Me M =Al Ga or In (51) Diazaphosphonia-aluminacyclobutanes(52) are formed in the reaction sequence shown in Scheme 15.19*‘ P (Me3Si),NP=NR +AIX -* [(Me,Si),N I -AIX ‘AT’ x2 R = SiMe or CMe3 X = C1 Br or I (52) Scheme 15 3 Gallium In frozen matrices of N or Ar containing oxygen both gallium and indium atoms react to produce metal superoxide molecules M+02-which are similar to those of the alkali and alkaline-earth metals.In addition to the superoxides various aggregate The Typical Elements 55 species are produced one of which was identified as the superoxide dimer which apparently has the structure 02M-MO of DZdsymmetry. Another aggregate identified as a rhombic M02M species is formed by addition of a metal atom to the superoxide. 199 The electronic absorption spectra of gallium and indium trihalides have been measured for the first time; the one-electron transitions responsible for the lowest energy group of absorption bands are all of the type ntz +3al (n= 1 2 or 3).'0° Dioxan reacts with gallium dihalides at 0°C to form the 1:2 complexes Ga,X -2diox (X = C1 Br or I).An X-ray investigation of the chloride revealed that the complex is a discrete molecule containing a Ga-Ga bond (2.406A) and unidentate dioxan groups in the chair conformation. It is thus the first example of a neutral complex of the unknown digallium tetrachloride C12GaGaC12. Spectro- scopic properties suggest that the bromide and iodide have similar structures.2o1 Gallium has deformed tetrahedral co-ordination of S and S,Te groups in EuG~~S,~'~ and Ga2S2Te203 respectively. Ethanolamine and trimethylgallium react in refluxing benzene with the evolution of methane and the formation of monomeric ethanolaminodimethylgallium H2NCH2CH20GaMe2(53).In the crystal the molecules are linked by an extensive network of N-H--0 hydrogen bonds which must be quite strong as fragments containing two and three gallium atoms can be identified in the mass spectrum of the vapour .204 Manganese molybdenum and tungsten carbonyl compounds of the terdentate chelating ligand dimethyl-( 1-pyrazoly1)ethanolaminogallate (54) have been pre- pared by the reactions M=Mo or W [M(CO),] +Nat(54)-Na'[(54)M(C0),]-+3CO THF 20°C [Mn(CO)5Br] +Na'(54)- -[(54)Mn(CO),] All of the complexes are monomeric octahedral species in which the ligand (54) is in a facial co-ordination The more sterically demanding ligand methyltris- (3,5-dimethylpyrazol- 1-y1)gallate (55) also acts as a terdentate ligand taking up a facial position in for example the octahedral complexes [(55)M(CO),] (M = Mo or lYyM.J. Zehe D. A. Lynch B. J. Kelsall and K. D. Carlson J. Phys. Chem. 1979,83,656. A. Bartecki and M. Sowinska Spectrochim. Actu 1979,35A 739. 201 J. C. Beamish R. W. H. Small and I. J. Worrall Inorg. Chem. 1979,18 220. '02 R. Roques R. Rimet J. P. Declercq and G. Germain Acru Cryst.. 1979 B35 555. 203 A.Mazurier S. Maneglier-Lacordaire G. GhCmard and S. Jaulmes Acta Crysf. 1979 B35 1046. 204 K. S. Chong S. J. Rettig A. Storr and J. Trotter Canad.J. Chem. 1979,57 586. '05 K. S. Chong and A. Storr Canad.J. Chem. 1979,57 167. 56 F. A. Hart A. G. Massey P. G.Harrison and J. H. Holloway W). However if it is attempted to introduce larger substituents on to the metal one of the dimethylpyrazolyl groups is cleaved from the gallium and replaced by OH [(MeCN),Mo(CO),] +C3H5Br+ Na+(55)-+ [{MeGa(Me2C3N2)20H}Mo(C0)2(~3-C,Hs)l In the above molybdenum complex the hydroxogallium group (56) is acting as a tris-chelating ligand.a N-N N-N eH2-C'H2 MeuMe All the spectral data for the complete series Ph,GaX,- (n = 1or 2 X = C1 Br or I) are consistent with the existence of discrete halogen-bridged molecular dimers in the solid state.2066 Triaryl-gallium and -indium derivatives are best made by treating the corresponding mercurials with gallium or indium metal. Their mass spectra show the presence of dimers in the gaseous phase.206c 4 Indium The synthesis of a number of chloro- and bromo-derivatives of indium such as InCl and InBr -3DMS0 may be accomplished electrochemically.207 Photoelectron and Auger spectra of indium metal and of the halides oxide and sulphide have been recorded; sample purity was shown to be very important.These compounds fall into two groups those with 0and F (or 'ionic') ligands and those with C1 Br I and S (or 'covalent') ligands.208 Indium(II1) hydroxide is isomorphous with Sc(OH) and La(OH),. Six oxygen atoms are octahedrally co-ordinated to each indium and each oxygen atom is co-ordinated to two indiums; the hydrogen atoms are disordered.,09 In the acid sulphate HIn(SO,) -4H20 there are layers perpendicular to the c-axis comprising indium atoms joined to four others by SO groups; the co-ordination polyhedron around indium is completed by two water molecules giving an In(H,O),O distorted octahedron.These layers are held together by hydrogen bonds to Hs02+ions and the compound must thus be formulated210 as H50,~[In(H,0),(S0,),]-. Indium has a co-ordination number of 8 in [In(MeC02),(2,2'-bipy)] and [In(MeCO,),( 1,lO-phen)] both the acetate and nitrogen ligands being bidentate.,l 206 (a) K. R. Breakell S.J. Rettig A. Storr and J. Trotter Cunad. J. Chem.,1979,57,139; (b) S. B. Miller and T. B. Brill J. Orgunometallic Chem. 1979,166 293; (c) S. B. Miller B. L. Jelus J. H. Smith B. Munson and T. B. Brill J. Orgunometallic Chem. 1979 170 9. '07 J. J. Habeeb and D. G. Tuck Inorg. Synth. 1979 19 257. 208 G. D. Nichols and D. A. Zatko Inorg. Nuclear Chem. Letters 1979 15 401.'09 D. F. Mullica G. W. Beall W. 0.Milligan J. D. Korp and I. Bernal J. Inorg. Nuclear Chem. 1979,41 277. 'lo J. Tudo B. Jolibois G. Laplace G. Nowogrocki and F. Abraham Acru Cryst. 1979 B35 1580. "' H. Preut and F. Huber 2.unorg. Chem. 1979 450 120. The Typical Elements Oxidative insertion of InX (X =Cl Br or I) into the Re-Re bond of decacar- bonyldirhenium carried out in xylene at 150-160°C gave the dimer [XIn{Re(CO),},] (57). The average In-Re bond lengths were 2.797 (Cl) 2.796 (Br) and 2.811 A (I).212 Indium metal reacts with decacarbonyldirhenium to give [Re4(CO),2{p3-InRe(CO)~}4] in which four rhenium atoms form an inner tetra- hedron. Above the centre of each face is an indium bound to three Re atoms of the inner tetrahedron and to a terminal Re(CO) unit; the rhenium atoms of the four Re(CO) groups define an outer tetrahedron.213 In octacarbonylbis-[p-(pentacar-bonylrnanganio)indium(~~~)]di-iron there is no Fe-Fe bond in the planar In,Fe ring (58),possibly because the acute angle at Fe (75.2') holds the two iron atoms apart.214 (57) Tris(trimethylsilylmethy1)indium may be prepared by action of the Grignard reagent on indium trichloride; the chloro-derivatives C1 In(CH2SiMe3)3.-,(n = 1or 2) are formed when In(CH,SiMe,) is treated with the stoicheiometrically correct amounts of InCl or HCl.The bulky ligand does not substantially alter the behaviour of these indium derivatives when compared with other analogous Dimeric (isopropylideneamino)dimethylindium,[Me,C=N-InMe,], produced from N-chloro-2-propanimine (Me,C=NCl) and trimethylindium possesses a centrosymmetric four-membered In2N2 ring.z16a The crystal data have been redetermined for the following indium selenides InSe (hexagonal) a-In,Se (rhombohedral) a-In2Se3 (hex.) P-In,Se (rhom.) y-In2Se3 (hex.) and S-In,Se (hex.).2166 5 Thallium Benzotriazolatothallium(1)consists of sheets of Tl' ions separated by benzotriazole ions.Each thallium is co-ordinated by three nitrogen atoms of the ligand at distances of 2.725-2.792 A and by three neighbouring nitrogens at 3.271-3.326 A in a distorted trigonal prismatic co-ordination. The Tl' ions are arranged in zig-zag chains in the metallic layers the layers being completely separated by the benzo- triazole anions which are packed very closely together and are directed with all the nitrogen atoms to the Tl' layer.The structure of the layers is similar to that predicted for the protection layer formed when metal surfaces such as copper are treated with the corrosion inhibitor benzotria~ole.~~' 212 H.-J. Haupt H. Preut and W. Wolfes Z. anorg. Chem. 1979 448,93. '13 H. Preut and H.-J. Haupt Acra Crysf. 1979 B35,1205. H. Preut and H.-J. Haupt Actu Cryst. 1979 B35 2191. 'lS 0.T.Beachley and R. N. Rusinko Znorg. Chem. 1979 18,1966. (a) F.Weller and U. Muller Chem. Ber. 1979 112,2039; (b) S.PopoviC A. Tonejc B. Grieta-PlenkoviC B. blustka and R. Trojko J. Appl. Crystallog. 1979 12,416. 217 J. Reedijk G. Rcelofsen A. R. Siedle and A. L. Spek Inorg. Chem. 1979 18 1947.58 F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway A kinetic study of the luminescence of the Tl' ion in aqueous solution shows that the emission does not arise from the initial excited species hYL [Tl(OH,)]*' $ [H-Tl-OH]*+ + TICaq + hv' In this scheme the initial absorption of a photon by the hydrated Tl' ion rapidly gives a thallous ion-water exciplex [Tl(OH,>]*' which by an intramolecular proton transfer process is in equilibrium with the emitting species.218 The absorption band observed in the visible spectrum of the ion-pair T~'[CO(CO)~]- is assigned to a direct cobalt-to-thallium charge transfer. It therefore provides a new method of deter- mining anion-cation association in a variety of solvents of differing dielectric constant and TlCdI consists of double chains of edge-sharing CdI octahedra with TI' ions between the double chains in nine-co-ordination.220 Stoicheiometric amounts of thallous iodide iodine and gold when heated give black crystals of T16Au,I,,; in a closed system this compound decomposes at 276°C.However in a vacuum de- composition occurs above 65 "C forming one mole of iodine; above 180 "C a second mole of iodine is formed giving TlI and Au.,~' Seven-co-ordinate thallium occurs in T1H2P04222 and cyclopropylbis(isobutyrato)thallium(~~~).~~~ Steric effects are important in determining the stability of the (TlX) four-membered rings in dimeric dialkylthallium amides and dimethylthallium diphenyl- pho~phide.'~~ An unsymmetrical bromine-bridged dimer unit occurs in bromobis- (2,3,5,6-tetrafluorophenyl)thallium(111);the short TI-Br distances between the dimer units suggest a significant bonding interaction which gives rise to polymeric chains.Each thallium has distorted trigonal-bipyramidal co-ordination with two carbons and a bromine occupying the equatorial The co-ordination of thallium in thallium(1) monohydrogen orthophosphate T12HP04,is dictated by the presence of the stereochemically important lone pair of electrons.226 Potassium rubidium and ammonium tetrachlorothallates having the CaWO structure crystallize from concentrated aqueous solutions of thallium(II1) chloride containing small amounts of MCL'~' 1,3-Diphenyltriazene and l-phenyl-3-(2'-pyridyl)triazene (HL) react with [(C6F,),fl(diOXan)] to form tris(triazenido)thallium(m) derivatives TlL3 in which the triazenido-groups are acting as bidentate chelating ligands2,' A novel desul- phination reaction allows easy access to tris(polyfluorophenyl)thallium(nI) compounds which are difficult to prepare by other rnean~:"~ R,zTlBr x (RFS02)2Ba(or TlO,SR,) -+ RF3Tl+ BaBr,(TIBr) + 2S02 RF= C6F5,4-HCsF4,or 2-HC6F4 'I8 T.M. Shepherd J.C.S. Faraday IZ 1979 75 644. '19 C. Schrarnrn and J. I. Zink J. Amer. Chem. Soc. 1979,101,4554. 220 H. W. Zandbergen G. C. Verschoor and D. J. W. Ijdo Acta Cryst. 1979 B35 1425. '"W. Stoeger and A. Rabenau Z. Naturforsch. 1979,34b 685. 222 Y. Oddon A. Tranquard and G. Pkpe Acta Cryst. 1979 B35,542. 223 F. Brady K. Henrick and R. W. Matthews J. Organometallic Chem.1979 165 21. 224 S. Bauer A. Zschunke and B. Walther 2.anorg. Chem. 1979,450 70. ''' G. B. Deacon R. J. Phillips K. Henrick and M. McPartlin Inorg. Chim. Acta 1979 35 L335. '"Y. Oddon J.-R. Vignalou A. Tranquard and G. Pepe Acta Cryst. 1979 B35 2525. '"G. Thiele B. Grunwald W. Rink and D. Breitinger Z. Naturforsch. 1979,34b 1512. 228 D. St.C. Black V. C. Davis and G. B. Deacon Znorg. Chim. Acta 1979,37 L528. 229 G. B. Deacon and R. J. Phillips J. Organometallic Chem. 1979 171 C1.

ISSN:0260-1818    

DOI:10.1039/IC9797600013

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

The Typical Elements Part 111 Groups IV and V By P. G. Harrison 1 GroupIV General.-Known literature values of heats of formation have been combined with kinetic and appearance potential data to yield self-consistent values of the bond dissociation energies D(Me3M-X) (M = Si Ge Sn or Pb; X = H Me MMe3 OEt OH C1 or Br).’ A separate report quotes values for several Group IV metal-halogen bonds.* Estimates of the intramolecular non-bonded atomic radii for the heavier P-elements have been revised including those for carbon (1.25A) silicon (1.55 A) germanium (1.58 A) and tin (1.82A). Carbon.-An ab initio MO study of CC13Li has indicated that the triply bridged species (l),with the lithium atom on the ‘wrong’ side of the molecule is the most stable c~nfiguration.~ Most interest has centred around fluorocarbon compounds.Both CF30H and CF,NH have been made by the reaction of the corresponding chloro-compounds CF30C1 and CF3NC12 with HCl at low temperature. CF,OH is a typical protonic acid comparable with HOSFS HOSeF, and HOTeF, whereas CF3NH2 is still basic in spite of the inductive effect of the CF group.5 CF,NCO is obtained oia a Curtius decomposition from Me,SiN and CF,COCl (Scheme 1). It is hydrolysed to CF,COCl+ Me3SiN3- CF3CON3+ Me,SiCl /6-ooc CF,NCO +N2 Scheme 1 a mixture of (FCN), CF,NHCOF and CF3NHCONHCF3 and reacts with SF4 OSF, and XeF to afford the well known compounds of CF3NSF2 CF3NSOF2 and CF,(FOC)NN(COF)CF, respectively.6 CF3CF2N=SF2 is a precursor of five- and six-membered heterocycles (Scheme 2).’ The presence of fluoride ion also induces ’ R.A. Jackson J. Organometallic Chem. 1979,166 17. H. Donald B. Jenkins and K. F. Pratt Inorg. Chim. Acta 1979 32 25. C. Glidewell Znorg. Chim. Acta 1979 36 135. T. Clark and P. von R. Schleyer J. Amer. Chem. SOC. 1979,101,7747. ’ G. Kloter and K. Seppett J. Amer. Chem. SOC.,1979,101 347. W. Lutz and W. Sundermeyer Chem. Ber. 1979,112,2158. ’0.Glemser and J. M. Shreeve Inorg. Chem. 1979,18 213 2139. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway -CF3CF,N=S/E] tiCF3CF,N=SF CF3C<t> + CF3CONH 'E r n Reagents i HE EH (E = 0 or NMe) NaF; ii HS OH NaF Scheme 2 the cyclization of CF3CN with similar 0-and S-containing reagents at room temperature (Scheme 3).CF3 NH2 CF3CN+ HE' E2Hd NaF CF3C(=NH)EFEZH 'c' _3 Scheme 3 LiF and PbF2 are unreactive towards CF300CFzNHCF3 but NaF KF CsF and KHF react to give initially CF,NCF,O. The final products of the reactions depend upon the fluoride reactivity and include CF3NFCOF CF3N(OCF3)COF and COF2.8 Chlorine(1) derivatives of perfluorinated carboxylic acids RFCO2C1 are best made by the low-temperature reaction of the sodium salts of the acids with ClF. These derivatives are unstable at ambient temperatures and explode in the gas phase at pressures greater than 20-50 Torr.' The C-C bond in (CF3S)3C-C(SCF3)3 is very weak [D(C-C) = 57.3 kJ mol-'1 and unusually long [1.62(4)813 owing to steric bulk of the CF3S groups. In benzene solution at moderate temperatures (10-60 "C) the compound undergoes reversible homolytic C-C bond dissociation giving (CF3S),C- radicals.10*'' Transient Silicon Intermediates.-Dimethylsilylene MezSi has been trapped in glassy hydrocarbon matrices at 77 K or an argon matrix at 10 K by the photolysis of (Me,Si),.The species is bright yellow and shows a broad electronic absorption band at 453 nm (e = 1500)(cf.SiH2 480-650 nm and SiHCl 500 nm)." This method of generation allows the storage of Me2Si6 as a preformed reagent since it is indefinitely stable at 77 K in the hydrocarbon glass. Photolysis of (Me,Si) in the presence of a-diketones affords the expected 1,3-dioxa-2-silacyclopent-4-enesilylene addition products (2).13 hv Me,Si -(2) ' A. Sekiya and D. D. Desmarteau Inorg. Chem.1979,18,919. I. Tari and D. D. Desmarteau Inorg. chem. 1979,18 3205. H. Oberhammer A. Haas and K. Schlosser J.C.S. Dalton 1979 1075. A. Haas K. Schlosser and S. Steenken J. Amer. Chem. SOC.,1979 101,6282. T. J. Drahnak J. Michl and R. West J. Amer. Chem. SOC.,1979 101 5427. '' W. Ando and M. Ikeno J.C.S. Chem. Comm. 1979,655. The Typical Elements Co-condensation of vinyl chloride with F2Si at 77 K gives products resulting from either ring closure or hydrogen atom migration of a biradical intermediate (Scheme 4).Only a very small amount of insertion product H2C=CH(SiF2Cl) (<1’/0) was H C1 ci H \ /. SiF \/ (SiF,), +CH =CHCl-H-C-q-H +c=c / H/\ (SiF,) cis and SiF,SiF2CH2CH2CI trans Reagent i CH,=CHCI Scbeme 4 obtained reflecting the preference for the initial radical attack on the two sides of the double bond.Again (cf. last year’s Report) it is unnecessary to invoke intermediate siliran or siliren species in the mechanism.14 The investigation of the generation electronic structure and reactions of multiply bonded silicon species has continued. Two ab initio SCF-MO studies of disilene Si2H4 have been reported. One” favours the disilene geometry (3) with a Si-Si distance of 2.15 A whereas the other16 suggests that the electronic structure of the ground state corresponds to a singlet silylsilylene (4) (Si-Si =2.408 A; SiSiH = 92.1”). Free rotation about the Si-Si bond in 1,2-dimethyl-l,2-diphenylsilene appears to be difficult since the addition of independently generated cis-and trans-isomers to anthracene proceeds with very high stereospecificity.l7 The reaction of the silyl-a-pyran (5) with hexafluorobut-2-yne provides a new convenient method for the generation of dimethylsilanone via elimination from the bridged species (6) which could not be observed even at room temperature. Thus when the cycloaddition is conducted in the presence of Me,Si(OMe) and trimethylsiloxybut-1-ene the respective Me3Si0 insertion products Me2(MeO)SiOSi(OMe)Me2 and H2C=CHCH(Me)OSiMe20SiMe3,are obtained in high yield. l4 C. S. Liu and H. L. Hwang J. Amer. Chem. SOC.,1979,101 2996. lS F. F. Raelandt D. F. Van de Vondel and G.P. Van der Kelen J. Organometallic Chem. 1979,165,151. l6 L. C. Snyder and 2.R. Wasserman J. Amer. Chem. Soc.1979,101 5222. ”H. Sakurai Y. Nakadaira and T. Kobayashi J. Amer. Chem. SOC.,1979,101,487. T. J. Barton and W. D. Wulff J. Amer. Chem. SOC.,1979 101 2735. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Relatively stable silaethylenes (7) have been prepared by the photolysis of acylpolysilanes (Scheme 5). In the absence of trapping reagents dimerization to (8) occurs but in the presence of methanol alkynes or dienes the products (9)-( 11)are formed. The silaethylene derived from pivaloyltris(trimethylsi1yl)silane is unusually stable and is in equilibrium with the corresponding dimer in solution at room temperature.l9*’O OSiMe (Me,Si),Si-C-RI OSiMe / L (Me3Si),SiCR (Me3Si)2Si=C -I I (Me,Si)$i-C-R I (8) OSiMe OSiMe I I (Me,Si),Si-C-R Me0 H OSiMe I I I (Me3Si)2Si-C-R PhC=CMe OSiMe (9) (10) bs Reagents i.hv; ii MeOH; iii PhC-CMe; iv. Scheme 5 Molecular Quadrivalent Compounds.-Several novel silylamido-metal derivatives have been prepared during the preceding year usually by metathesis between the sodium or lithium silylamide and the metal chloride. The chromium(11) and manganese(I1) silylamides [ClCrN(SiMe3)2(L),] [Cr{N(SiMe,),),(LL)] (LL= aliphatic or cyclic ethers alkyl cyanides or aromatic tertiary amides) and [Mn{N(SiMe,),},(THF)] are extremely oxygen The rhenium oxosilyl- amide [ReO{N(SiMe,),},] is moderately air-stable and does not react with such reagents as COz CS2 PMe, or Na/K alloy., The zirconium and hafnium deriva- tives [CIM{N(SiMe,),),] (M = Zr or Hf) are surprisingly inert being stable to air and water and are not hydrolysed by mineral acids.They may however be converted into the corresponding methylmetal derivatives by methyl-lithi~m.,~ [C1,Ta{N(SiMe3),},] also reacts with methyl-lithium to afford the expected methyl- tantalum complex [Me3Ta{N(SiMe3)t}z] ; however reaction with LiCHzSiMe3 affords the alkyl-alkylidene complex [(Me3SiCHz)(Me3SiCH>Ta{N(SiMe3)2)23.’” l9 A. G. Brook J. W. Harris J. Lennon and M. El Sheikh J. Amer. Chem. SOC.,1979 101 83. 2o A. G. Brook S. C. Nyburg W. F. Reynolds Y. C. Poon Y.-M.Chang J. S. Lee and J. P. Picard J. Amer. Chem. SOC.,1979,101,6750. ” B. Horvath J. Strute and E. G. Horvath Z. anorg. Chem. 1979 457 38. 22 B. Horvath R. Moseler and E.G. Horvath 2.anorg. Chem. 1979,450 165. 23 P. Edwards G. Wilkinson K. M. Abdul Malik and M. B. Hursthouse J.C.S. Chem. Comm.,1979,1158. 24 R. A. Anderson Znorg. Chem. 1979,18 1724. ’’ R. A. Anderson Znorg. Chem. 1979 18 3622. The Typical Elements 63 Several uranium and thorium silylamides have been prepared including [U{N(SiMe3)2}3],26[U02{N(SiMe3)2}2].2THF,26[ClM{N(SiMe3)2}3] (M = and U or Th),,' the chlorine in which is readily replaced by MeLi Me2Mg or LiBH4. The attempted replacement of the fourth chlorine atom in these compounds using NaN(SiMe3)2 in THF unusually affords the hydrides [{(Me3Si)2N}3MH] the hydr- ogen arising from the solvent; [2H,]THF gives [{(Me3Si)2N}3MD] compounds.28 When these uranium and thorium hydrides are stirred under an atmosphere of deuterium at room temperature complete though reversible perdeuteriation occurs giving [{[(CD,),Si],N},MD] derivatives thought to occur via an intramolecular H-D exchange reaction (Scheme 6).29 D--D J [(Me,Si),N],MLH -[(Me,Si),N],MD + HD SiMe SiMe I I SiMe SiMe Scheme 6 Cyclic beryllium silylamides (12) have been obtained by reaction of BeMe with the appropriate aminosilanes.The compounds are associated in both solution and the solid state in which phase dimerization via a centrosymmetric [BeN-Be"] ring has been shown by X-ray diffraction for E = CH,.30 rE\ Me,Si SiMe2 I 1 MeN ,NMe Be E = - CH2NMe or 0 26 R. A. Anderson Inorg. Chem. 1979 18 209 1507. 27 H. W. Turner R. A. Anderson A. Zalkin and D.H. Templeton Inorg. Chem. 1979,18 1221. H. W. Turner S. J. Simpson and R. A. Anderson J. Amer. Chem. SOC. 1979,101 2782. 29 S. J. Simpson H. W. Turner and R. A. Anderson J. Amer. Chem. SOC.,1979,101,7728. 30 D. J. Brauer H. Burger H. H. Moretto V. Wannagat and K. Wiegel J. Organometallic Chem. 1979 170 161. 64 F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway The cyclic distannazane (13)undergoes a variety of ring-expansion and -cleavage reactions (Scheme 7).31 S R,Sn’ ‘SnR Me C02Me ‘S’ \I vi R2Sn,y-y\,C-C0,Me Me :e 7 ,N-SnR, I R,Sn-A-SnR & RzSn( )SnR Me I N II / R,Sn -N=C-N-SnR Me Ph I I N=C< CI c1 R2Sn’ N/Me I I Me-N ,SnR2 ‘C=N / Ph Reagents i MeO,CC=CCO,Me; ii PhN=C=NPh; iii 2PhCN; iv Bu:SnCI,; v 2PhCN; vi 2CS or 2PhNCS Scheme 7 Cleavage of phenyl groups from cyclo-Si,Ph using HC1-AlC1 results in the formation of the new cyclic silicon compound ~yclo-Si~Cl~.~~ Ring opening occurs on treatment with tetrachloroethylene to give the open-chain compound Si4Cllo which is also obtained by photolysis of Hg(SizC15)2.33 A simple synthesis of Hg(SiMe,) has been reported involving the reaction of Me3SiC1 with mercury and aluminium metal in THF.The product is readily isolated from the reaction mixture by ~ublirnation.~ A similar procedure has been employed in the synthesis of Li[Al(SiMe,),] solvated by ether THF orDME. Unsolvated material may be obtained by repeated subli- mation of the ether ~olvate,,~ and Li[A1(SiMe3),].2 DME reacts with ZnC1 and Cd(OAc) to afford the rather unstable bis(trimethylsily1)-zinc and -cadmium derivative^.,^ Electrochemical generation of metal-metal bonded compounds is becoming more common.Electrochemical oxidation of zinc cadmium or mercury in a non-aqueous solution of Ph3SnC1 yields solvated compounds such as Ph3SnMCl.tmed (M = Zn Cd or Hg) and Ph3SnCdCl.bipy.37 Complexes containing both a Group IV metal and a transition metal continue to attract attention. Although most of the complexes studied in the past year contain a direct metal-metal bond the complex (14),which undergoes a ring contraction to 31 D. Hanssgen and I. Pohl Chem. Ber. 1979,112 2798. 32 E. Hengge and D. Kovar Z. anorg. Chem. 1979,458 163. 33 W. Ram1 and E. Hengge Z.Naturforsch. 1979,34b 1457. 34 R. Lutze and E. Wolfgang Chem. Ber. 1979,112 394. 3s L. Rosch and G. Altnau Chem. Ber. 1979,112 3934. 36 L. Rosch and G. Altnau Angew. Chem. Internat. Edn. 1979 18 60. 37 J. J. Habeeb A. Osman and D. G. Tuck Znorg. Chim. Acra 1979 35 105. The Typical Elements 65 (15) on thermolysis at 160 "C is formed by reaction of 3,6-diphenyl-1,2-disilahexa-3,5-diene with either [Fe(CO)J or [FeZ(C0)9].38 Photolysis of the four-membered ring compounds [(C0),FeSiMeRI2 (R = Me or Cl) yields the complexes (16).39 The heterocycle (17)has a 'ring-chair' conf~rmation.~~ (16) (17) Methylgermane and [(MeGeHz)Co(CO)4] each undergo a complex reaction with [coz(co)8] 1] as the principal leading to the formation of [MeGeC0(c0)~ The same compound and the bromo-analogue may also be obtained by substitution of MeGeC1 and GeBr4 with N~CO(CO),.~~ Thermolysis of the methyl derivative at 80 "C affords the germylidenetricobalt nonacarbonyl cluster [M~G~CO~(CO)~] the tin analogue of which results from the reaction of Me2SnC1 and [Co2(CO),] in benzene.43 The room-temperature reaction of NaCo(CO) with halogermanes or of [co2(co)8] with GeH gives a complex of composition [GeCo,(CO),,] assigned a structure in which a germanium atom bridges two CO~(CO)~ units.Further CO elimination occurred at 50 "C affording the [(OC),CoGeCo,(CO),] cluster species the structure of which is analogous to those of similar methylide and silylidene complexe~.~~*~~ [w(co)6] reacts with LiSiMe,Ph3- (n= 1 or 3) followed by methylfluorosul- phate to yield the silylcarbene complexes [(CO)5W{C(OMe)SiMe,Ph3-n}].Amino-lysis affords the corresponding dimethylamino-complexes.With Ga2C16 or A12B1-6 at low temperature such tungsten complexes and their chromium analogues are converted into the thermolabile silylcarbyne complexes [X(CO),M~(CSiMe,Ph,-,,)] (X = C1 or Br M =Cr or W).46 The carbene complex Y. Nakadaira T. Kobayashi and H. Sakirai J. Organometallic Chem. 1979 165,399. 39 G. Schmid and E. Wetz Z.,Naturforsch. 1979 34b 929. 40 U. Schubert and A. Rengstl J. Organometallic Chem. 1979 166 323. 4' R. F. Gerlach B. W. L. Graham and K. M. Mackay J. Organometallic Chem. 1979,182 285. 42 G. Etzrodt and G. Schmidt J. Organometallic Chem. 1979,169,259.43 K. E. Schwarzhans 2.Naturforsch. 1979 34b 1456. 44 R. F. Gerlach K. M. Mackay and B. K. Nicholson J. Organornetallic Chem. 1979 178 C30. " R. Boese and G. Schmid J.C.S. Chem. Comm. 1979,349. 46 E. 0.Fischer H. Hollfelder and F. R. Kreissl Chem. Ber. 1979 112 2177. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway [(CO),Cr{C(NEt2)SnPh3}] rearranges spontaneously at room temperature both in the solid state and in solution to give the carbyne complex [Ph,Sn(CO),(Cr~CNEt,)] stable under nitrogen.,' X-Ray analysis shows the CrCN linkage to be almost linear but the ReCSn linkage in the carbyne-like complex [Sn(tpp)(CRe(CO),},] (tpp =tetraphenylporphyrin) is non-linear an observation for which no reasonable explanation is yet forthcoming.This complex results from the reaction of Sn(tpp) and [Re2(CO),,] at 160 "C. However when the same reaction is carried out at 180 "C the expected complex [Sn(tpp){Re(CO)3}2] is ~btained.~~'~~ X-Ray diffraction studies of inorganic compounds are now more or less routine. The most remarkable study reported in 1979 concerns Si(o-02C6H4),. The reaction of catechol with SiCl produces polymeric material but complex depolymerization takes place on sublimation. Condensation from the gas phase yields a very moisture- sensitive colourless crystalline modification which is monoclinic space group P2'/c with 2 =2. The two silicon atoms in the unit cell therefore lie on special centrosymmetric equivalent positions meaning that the molecules must be planar in the crystal.The carbon analogue possesses the expected slightly distorted tetra- hedral geometry. MO calculations however show that for silicon the tetrahedral arrangement is only 6.4 kcal mol-' more stable than a planar geometry whereas the difference for carbon is quite considerable (104.4 kcal m~l-').~~~~' In bis-(2,2'- bipyridyl)silicon(O) formed by low-pressure sublimation of tris-(2,2'-bipyridyl)sili-con(O) both ligands chelate silicon in a distorted tetrahedral Other four-co-ordinate silicon compounds of interest that have also been studied include (Me,SiN),S'" at -130"C which exhibits planar three-fold co-ordination of S'" [(Me3CN),S is similar],53 the monoclinic form of cyclo-(Ph,SiO), which is unusually flat (probably owing to intramolecular steric effects) and the acetone solvate of octa(phenylsi1asesquioxane) (18).54 The unexpected linearity of the SiOSi linkage in (Ph,Si),O was mentioned in last year's Report.Perhaps even more surprising is the linearity (crystallographically enforced) of the MOM linkage in [(PhCH2),MI20 (M = Ge or Sn) [cf.bond angles in 47 E. 0.Fischer H. Fischer U. Schubert and R. B. A. Pardy Angew. Chem. Internat. Edn. 1979,18,871. 48 S. Kato I. Noda M. Mizuta and Y. Itoh Angew. Chem. Internat. Edn. 1979 18 82. 49 I. Noda S. Kato M. Mizuta and N. Yasuoka Angew. Chem. Internat. Edn. 1979 18 83. H. Meyer and G. Nagersen Angew. Chem. Internat. Edn. 1979,18 551. 51 E. U. Wiirthwein and P. von R. Schleyer Angew. Chem. Internat. Edn. 1979.18 553. " R. Morancho P. Pouvreau G.Constant J. Jaud and J. Galy J. Organometallic Chem. 1979,166,329. 53 S. Pohl B. Krebs U. Seyer and G. Henkel Chem. Ber. 1979,112 1751. 54 M. A. Hossain M. B. Hursthouse and K. M. Abdul Malik Acta Crysr. 1979 B35,522 2258. The Typical Elements 67 (Ph3M)20 Ge 135.2'; Sn 137.3'). The observed linearity was interpreted in terms of the low electronegativity of the metal coupled with the electron-donating character of the organic group.55 Both (Ph3Ge)2S56 (GeSGe = 110.9') and (Ph3Sn)2Se57 (SnSeSn = 104.3') are as expected bent at the Group VI atom. Yellow trimeric (Me2SnTe)3 is obtained by the reaction of Me2SnC12 and NaHTe in water but is only stable for a few days in the absence of air in the dark at room temperature. The structure (determined at 110K) shows the presence of two enantiomeric trimeric molecules in the cry~tal.'~ Whereas crystals of Ph3MBr (M = Ge or Sn)59 and (~yclo-C~H~~)~SnCl~~ contain discrete tetrahedral molecular units the structure of Me3SnCl (at 135 K) consists of weakly intermolecularly chlorine-bridged infinite one-dimensional chains.61 The compound thus resembles Me3SnF and many other trimethyltin compounds.The structure of Me3Sn02C(C5H4N-2).H20 is similar to those of Me3Sn(03SPh).H20 and Me3SnN03.H20 with the usual trigonal-bipyramidal stereochemistry at tin in which axial sites are occupied by water and unidentate carboxylate ligands. Adjacent units are however linked by a rather complex three-dimensional hydrogen-bonding network involving the pyridyl nitrogen the carbonyl oxygen and the water molecule (cf.the one-dimensional system of the other two compounds).62 The dithiophosphate group invariably functions as either a chelating or a bridging group but in Ph,Sn[SP(S>(OEE),] the tin is tetrahedrally co-ordinated and the ligand ~nidentate.~~ Oxidation of the disphosphine ligand takes place when Ph3SnN03 and Ph2PCH2CH2PPh2 are mixed yielding the phosphine oxide complex Ph3Sn(N03)(OPPh2CH2CH2PPh20), which has the dinuclear structure (19).64 ON02 " C.Glidewell and D. C. Liles J.C.S. Chem. Comm. 1979,93;J. Organometallic Chem. 1979,174,275; Acta Cryst. 1979 B35 1689. 56 B. Krebs and H. J. Korte J. Organornetallic Chem. 1979 179 13. '' B. Krebs and H. J. Jacobsen J. Organometallic Chem.1979,178,301. A. Blecher and M. Drager Angew. Chem. Znternat. Edn. 1979,18,677. 59 H. Preut and F. Huber Acta Cryst. 1979 B35 83 744. 6o S. Calogero P. Ganis V. Peruzzo and G. Tagliavinin,J. Organometallic Chem. 1979,179 145. 61 M. B. Hossain J. L. Lefferts K. C. Molloy D. van der Helm and J. J. Zuckerman Znorg. Chim. Acra 1979,36 L409. 62 P. G. Harrison and R. C. Phillips J. Organometallic Chem. 1979 182 37. 63 K. C. Molloy M. B. Hossain D. van der Helm J. J. Zuckerman and I. Haidue Znorg. Chem. 1979,18 3707. M. Nardelli C. Pelizzi and G. Peiizzi Znorg. Chim. Acta 1979,33 181. 68 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway The structures of several complexes with chelating ligands have been reported including Me2CISnSCH2(NH2)C02Et"' and C13SnCH2C02Me,66 both of which have a distorted trigonal-bipyramidal geometry and the octahedral complexes C12Sn(CH2CH2C02Me)2,66 C12Sn(CH2CH2CONH2)2,66 and C12Sn(OCEtCH2COMe).67a,p,y,S-Tetraphenylporphinatodihydroxytin(1v)repre-sents a rare example of a tin compound with two hydroxy-groups attached to the metal.From a combination of structural and Mossbauer data it was deduced that the tin atom vibrates with greater amplitude in the plane of the phorphyrin residue. However the temperature coefficient of the vibration is significantly larger in the out-of-plane direction (along the OSnO axis) reflecting the constraining nature of the porphyrin residue.68 Tin(1v) acetate possesses an eight-co-ordinate dodeca- hedral geometry very similar to that of tin(1v) nitrate.69 Bivalent Germanium Tin and Lead Derivatives.-Amine derivatives of germanium(I1) and particularly tin(I1) have continued to arouse interest.Monomeric coloured crystalline bis-( 2,2,6,6-te tramet h ylpiperidyl) -germanium( 11) and -tin (11) have been obtained by the usual metathetical method. The lead analogue is markedly less stable and decomposes below 0 "C. An electron diffraction study of the tin(I1) silylamide Sn[N(SiMe,),] shows that only the monomer which as expected has C2" symmetry (NSiN = 96.0"),is present at ca. 100"C and atm." The colour associated with some aminotin(I1) derivatives appears to arise when the compounds are monomeric i.e. when association via nitrogen bridging and co- ordination of solvent is absent.Thus for example although the derivatives already mentioned are monomeric and coloured dimeric Sn(NMe,) and the pyridine adduct of Sn[N(SiMe3)2]2 are both colo~rless.~~ The diazasilastannetidine (20) undergoes quantitative cleavage with ButNH2 at 50 "C in benzene to give depending on the molar ratios of the reactants employed the cage molecules (21)and (22). The latter compound is converted into the cubane (23) by heating to 240 "C at 5 T~rr.~ But BUf Bu' BU' But The dialkylaminotin(r1) derivatives Sn(NR,) (R = Me or Et) form 1:3 adducts with BF,. The initial site of co-ordination appears to be the bivalent metal 65 G. Domazetic M. F. Mackay R. J. Magee and B. D. James Znorg. Chim. Actu 1979,34 L247. P. G. Harrison T. J. King and M. A. Healy J. Orgunometullic Chem.1979 182 17. 67 J. Angenault C. Mondi and A. Rimsky Znorg. Chim. Acta 1979,33 137. 68 P. G. Harrison K. C. Molloy and E. W. Thornton Znorg. Chim. Actu 1979,33 137. 69 N. W. Alcock and V. T. Tracy Acru Cryst. 1979 B35 80. 70 M. F. Lappert P. P. Power M. J. Slade L. Hedberg K. Hedberg and V. Schomaker J.C.S. Chem. Comm. 1979,369. 71 P. J. Corvan and J. J. Zuckerman Znorg. Chim. Actu 1979 34 L255. 72 M. Veith M. L. Sommer and D. Jager Chem. Ber. 1979,112 2581. The Typical Elements 69 subsequent co-ordination occurring at the nitrogen atoms.73 With photochemically generated [M(CO),.THF] (M = Cr Mo or W) [Sn(NMe2)2]2 yields the dimeric complexes (24) which undergo dissociation in THF solution and react with [Fe(CO)J to afford the complexes (25).74 NMe2 THF 2[M(CO)5.THF]+ [SII(NM~,)~]~ (C0)5M-Sn-NMe2 + [(CO),MSn(NMe2)J2 gF / v THF (24) The '1 1 adducts' between MBr (M = Ge or Sn) and But3P are actually the phosphonium salts [Bu'~PB~]'MB~~-.~~ Mixed-valence germanium ylides But2f'(GeX3)GeX2(X = C1 or Br) result from the interaction of But2GeX and GeX4 in aromatic hydrocarbon and the organoarsenic-bridged stannic complexes (26),which are postulated to be structurally related to But2AsSnC1 (27) are obtained by the reaction of [(OC)5MSnC12.THF] complex and Me3SiA~B~t2.77 A similar chain structure has been determined for both chloro(phosphinato)-germanium(@ and -tin@) in which adjacent metal atoms are bridged by phos- phinate groups.78 Germanium(I1) ethoxide is stabilized in hydrocarbon solution by the presence of small amounts of ethanol which co-ordinates to the metal.With n-propanol transesterification takes place yielding the corresponding propoxide and with Me1 oxidative addition followed by ligand redistribution occurs.79 Tin(I1) oxalate has an 73 C. C. Hsu and R. A. Geanangel Znorg. Chim. Acta 1979,34 241. 74 W. Petz J. Organometallic Chem. 1979 165. 75 W. W. Dumont Z. anorg. Chem. 1979,458 85. 76 W. W. Dumont and G. Rudolph Inorg. Chim. Acta 1979 35 L341. 77 W. W. Dumont Z. anorg. Chem. 1979,450 57. '' T. J. R. Weakley and W. W. L. Watt Acta Cryst. 1979 B35 3023. 7q L. Silverman and M. Zeldin Inorg. Chim. Acta 1979 37 L489. 70 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway infinite chain structure in which tin.atoms and oxalate groups alternate (28). The structure of K2Sn(C204)2.H20 is similar but in this case the chains contain [Sn(C204)2]2- anions linked by hydrogen bonds to water molecules (29). In each case the in atom has square-pyramidal co-ordination similar to that in anhydrous Sn0.80 In contrast K[Sn(02CCH2C1)3] consists of discrete pyramidal [Sn(O2CCH2C1),]- anions and independent cations.81 Bis(pentamethylcyclopentadienyl)tin(II) from SnCl; and LiC5Me5 in ether undergoes oxidative addition with SnC14 Br2 and I to afford the corresponding diorganotin(1v) dihalides.82 The most interesting reaction of this compound however is that with HBF to give the colourless very light- and air-sensitive crystals of [(C5Me5)Sn]'BF4- which contain isolated cations and anions.The Sn-C bond distance in the cation (30) is considerably shorter [2.46(2)A] than in either (C5H&Sn (2.71 A) or (C5H5)SnCl (2.61 A).83 A structure similar to (30) was previously postulated for the complex (C5H5)SnA1Cl4. The reaction of (C5HJ2Sn with Me5Sb yields [Me4Sb]'2[(C5H5)4Sn]2- the first example of an anionic tin(I1) BF3 and (C5H5),Pb form a 1:1 complex (C5H5),Pb.BF3 which is thermally stable insoluble and presumably polymeric (31)? -9 -+ Sn -I The principal current interest in Pb" lies in complexation by macrocyclic ligands. Lead(I1) salts act as templates for the cyclic condensation of organic dicarbonyl compounds with polyfunctional diprimary amines to yield complexes of macrocyclic Schiff -base ligands in moderate-to-good yields.Four types of complex have been obtained in this way (i) mononuclear complexes of 15- and 17-membered quinque- dentate N5and N3ligands (ii) mononuclear complexes of 18-membered sexidentate N6 ligands (iii) dinuclear complexes of 18-membered sexidentate N30 and N2O4 ligands and (iv) dinuclear complexes of a 30-membered N604 ligand. The co- ordination number of lead in these complexes varies between five and eight and A. D. Christie R. A. Howie and W. Moser Inorg. Chim. Acta 1979 36,L447. S. J. Clark J. D. Donaldson J. C. Dewan and J. Silver Acta Cryst. 1979 B35,2550. '* P. Jutzi and F. Kohl J. Organometallic Chem.,. 1979 164,141. 83 P.Jutzi F. Kohl and C. Kruger Angew. Chem. Znternat. Edn. 1979 18 59.84 K. D. BOS,E. J. Bulten H. A. Meinema and J. G. Noltes J. Orgunometallic Chem. 1979 168 159. 85 A. K. Holliday P. H. Makin and R. J. Puddephatt J.C.S. Dalton 1979 228. The Typical Elements 71 depends on the nature of the anions present as well as on the macrocy~le.~~*~~ The structures of three complexes have been investigated crystallographically. 1,4,8,11- Tetra-azacyclotetradecaneand Pb(N03)2 form a molecular 1:1 complex in which the two unidentate nitrate groups occupy cis positions in a distorted octahedral geometry about lead (32). The lone pairappears to be stereochemically inactive.88 Lead is also six-co-ordinated (by the five nitrogen atoms of the macrocycle and a sulphur atom of a thiocyanate) in the complex {2,15-dimethy1-3,7,10,14,20-penta-azabicyclo[ 14,3 lleicosa- 1(20),2,14,16,1 8-pentaene}( thiocyanato)lead(~I) thio-cyanate [Pb(CI7H2,N,)(SCN)]'SCN-, but in this case the lone pair is stereochemic- ally active.89 The structure of the lead(I1) complex of the nitrogen analogue of [18]annulene PbL(C10J2.2H202 (L = C28H20N6) shows it to contain discrete [PbL(OH2)I2' cations in which the metal enjoys distorted hexagonal-pyramidal co-ordination.The macrocycle is not quite planar and the lone pair presumably occupies the second axial site of the r/l-bipyramid. 2 GroupV Nitrogen.-In contrast to most simple amines but like N(SiH,), the two difluoro- phosphinoamine derivatives N(PF2) and NH(PF2)2 have planar geometries at The latter compound and NH(PF,)(SiH,) undergo silylation with SiBrH3 and NEt to give N(PF2),(SiH3)(3-n) (n = 1 or 2) which form borane adducts on treatment with B2H6.92 NH(PF2)(SiH3) also reacts with PF to afford NH(PF,)(PF,) for which structure (33)was proposed.At low temperature the axial fluorine atoms on the phosphorus(v) atom are inequivalent indicative of restricted rotation around the P-N bond.93 F (33) 86 D. H. Cook D. E. Fenton M. G. B. Drew A. Rodgers M. McCann and S. M. Nelson J.C.S.Dalton 1979,414. M. G.B. Drew J. de 0.Cabral M. F. Cabral F. S. Estio and S. M. Nelson J.C.S. Chem. Comm. 1979 1033. N. W.Alcock N. Herron and P. Moore Inorg. Chim.Acta 1979,32 L25; J.C.S. Dalton 1979 1486. 89 M. G. B. Drew and S. M. Nelson Acta Cryst. 1979 B35,1594. 90 D. E. J. Arnold D. W. H.Rankin M. R. Todd and R. Seip J.C.S. Dalton 1979 1290. 91 M. J. Barrow E. A. V. Ebsworth M. M. Harding and S. G. D. Henderson J.C.S.Dalton 1979,1192. 92 E. A. V. Ebsworth D. W. H. Rankin and J. G. Wright J.C.S. Dalton 1979 1065. 93 D. W. H. Rankin and J. G. Wright J. C. S. Dalton 1979 1070. 72 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway The photolysis of trans-methyldiazene at 77 K promotes its isomerization to the cis-i~omer.~~ Several energy data have been determined for diazene itself ipcluding (kcalmol-') heat of formation (32) N=N bond dissociation energy (122) and enthalpy of isomerization to isodiazene (13).95 Diazene is usually obtained by the thermolysis of MN2H2tosyl (M=alkali metal) salts but when it is formed by the reaction of Me3SiN=NSiMe3 with acids ammoniu? azide results via intermediate tetrazene f~rmation.'~ Dimethylisodiazene Me2N=N has been proposed as an intermediate in the pyrolysis of 2,2-dimethyltriazanium chloride [Me2N(NH2)2]'CI-:97 Me2NN=NNMe2 + -7 [Me2N(NH2)2] +,Cl- -B NH4CI + Me2N=N L Me2NN=CH2 + CH4+ N2 The oxidation of hydroxylamine by nitric acid yields N20 and HNO in different proportions varying with the reaction conditions.In the suggested mechanism the nitroxyl biradical HNO is formed by oxidation of unprotonated H2NOH by N204 and is oxidized further to give HN02 which reacts with H2NOH to produce N20.98 Crystals of Na3N04 contain tetrahedral Nos3- anions which have very short N-0 distances (1.387-1.393 A; cf. 1.50A for a N-0 single bond) owing to the superimposition of a polar interaction on the single bond.This observation demon- strates rather emphatically that pv-dv bonding contributions need not be invoked in explaining the bond distances in other anions such as SO,2-and ClO,-.'' Sulphur-Nitrogen Compounds.-The unusually high electrical conductivity of certain S-N-materials has led to much activity in this area and the structure and bonding in cyclic S-N-compounds has been reviewed."' A molecular beam analysis of the vapour of polymeric (SN) has shown it to consist mainly of tetrameric (SN) along with other species such as S4N2 S3N3,S3N2 S2N and SN."' Similar products are also obtained in the pyrolysis of S4N4. At ca. 200 "C the major product is S,N accompanied by smaller amounts of S3N3 and S4N2 but at higher temperatures (>3OO0C) S2 SN and N2 become the major products.102 Chlorination of S4N4 yields N4S4C12 which can be converted into the corresponding fluoride by treatment with NaF;Io3 however the products of bromination vary markedly with the condi- tions.Treatment of solid S4N4with bromine vapour affords polymeric (SNBro.,), but with liquid bromine S4N3+Br3- in which the cyclic cation is essentially planar is ~btained."~In CS2 solution a mixture of products including S4N3Br3 S4N3Br and CS3N2Br2,for which the structure (34) was suggested results.'os The structure of the 94 N. C. Craig M. A. Kliewor and N. C. Shih J. Amer. Chem. Soc. 1979 101 2480. 95 N. Wiberg G. Fischer and H. Bachtruber Z. Naturforsch. 1979 35b 1385.96 N. Wiberg H. W. Haring and S. K. Vasisht Z. Naturforsch. 1979 34b 356. 97 M. A. Mathur H. H. Sisler and L. N. Morgenthaler Inorg. Chem. 1979 18 2350. 98 J. R. Pembridge and G. Stedman J.C.S. Dalton 1979 1657. 99 M Jansen Angew. Chem. Internat. Edn. 1979 18 698. loo H. W. Raesley Angew. Chem. Internat. Edn. 1979 18 91. lo' R. R. Cavanagh R. S. Altman D. R. Herschbach and W. Klernperer J.Amer. Chem. Soc. 1979,101 4734. R. D. Smith J.C.S.Dalton 1979,478. '03 I. Zborilova and P. Gebauer 2.anorg. Chem. 1979,448 5. J. J. Mayerle G. Wolmershauser and G. B. Street Inorg. Chem. 1979 18 1161. G. Wolrnershauser G. B. Street and R. D. Smith Znorg. Chem. 1979 18 383. The Typical Elements adduct S,N,.FSO,NCO is very similar to the adducts of S4N4 with SO3,BF3 and SbC15 and involves co-ordination of a ring nitrogen atom to the carbonyl carbon atom (35).The ring has a modified saddle conformation.'06 0 Treatment of S3N3Cl with Me3SiN=NSiMe3 in CCl yields the salt S4NS'CI- which has a polymeric predominantly ionic structure in which bicyclic S4N5+ cations (36)are symmetrically bridged by chloride anions. Ab initio MO calculations for the cation show that the introduction of the bridging nitrogen into the related S4N4 framework (37)destroys one of the transannular S.-S bonds and weakens the S-N (36) (37) framework bonds.'" Thermal decomposition of the corresponding anion S4N5-, in MeCN proceeds sequentially to the anions S3N3- and S4N- which has a planar cis-trans chain structure.lo* S,N,Cl reacts with silyl compounds forming the bicyclic derivatives (38) and (39). The latter is also produced by the reaction of S3N3Cl with (Me3SiNMe)2C0.'"g."o Me' N '0' N 'Me II 0 (38) (39) 106 A. Gieven C. Hahn B. Dederer H. W. Roesky and N. Amin Z. anorg. Chem. 1978,447 179. T. Chivers L. Fielding W. G. Laidlaw and M. Trsic Inorg. Chem. 1979,18 3379. T. Chivers and R. T. Valdey J.C.S. Chem. Comm. 1979,752. '09 H. W. Roesky J. Miiller and E. Rodek J.C.S. Chem. Comm. 1979,439. 110 H. W. Roesky C. Graf M. N. S. Rao B. Krebs and G. Henkel Angew. Chem. Internat. Edn. 1979,18 780. F.A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Nucleophilic attack of methoxide on cyclo-S4N402 occurs at the sulphur atom most remote from the sulphonyl group affording the anion (40).'11Treatment with N(SnMe,) results in stannylation of the eight-membered ring to give (41) but with N(SiMe3)3 a ring contraction occurs affording the silylated six-membered ring compound (42).112*113 Arsenic analogues of S4N4 have been prepared by the reaction of ArAsC12 (Ar=Ph or C6H2Me3) and Me3SiN=NSiMe3 and exhibit a similar saddle conformation (43).'14 (40) (41) (42) (43) The structures of two six-membered S-N rings have been determined.The S3N3-anion is planar with D3,,~ymmetry,~" and the endocyclic oxygen atom of (44) forms bonds of different length to the two sulphur atoms.116 The shape of the four- membered S2N2 ring depends on the nature of the ligands. Thus whereas (45) is non-planar (46) is completely planar."' Molecular Phosphorus and Arsenic Compounds.-The crystal structure of PC1 has been determined at -1 10OC.ll' Tris(hydroxy)phosphine P(OH), like many other unstable species may be stabilized by co-ordination to a transition metal.The '11 H.W. Roesky M. Witt B. Krebs and H. J. Korte Angew. Chem. Internut. Edn. 1979,18,415. 11* H. W. Roesky M. Witt J. W. Bats H. Fuess F. J. BaltaCalleja andF. Ania 2.anorg. Chem. 1979,458 225. '13 H. W. Roesky M. Witt M. Diehl J. W. Bats and H.Fuess Chem. Ber. 1979,112 1372. '14 N. W. Alcock E. M. Holt J. Kuyper J. J. Mayerle and G. B. Street Inorg. Chem. 1979,18,2235. 11' T. Bojes T. Chivers W. G. Laidlaw and M. Trsic J. Amer. Chem. Soc. 1979 101,4517. '16 E. Rodek N. Amin and H.W.Roesky 2.anorg. Chem. 1979,457,123. ''' F. M. Tesky R. Mews and B. Krebs Angew. Chem. Internat. Edn. 1979,18,235. H. Hartl M. Rama A. Simon and H. J. Delseroth Z. Nururforsch. 1979,34b 1035. The TypicalElements 75 complex [(OC)5Cr.P(OH)3] is a weaker acid than OP(OH)3 and reduces Ag' to silver meta1.'19 Structural data have shed some light on the unusual air-stability of P(CH,CN),. The P-C bond distances are somewhat large and the CPC angles smaller than for example in PMe3 consistent with increased p-character for the P-C bonds and hence greater s-character for the lone pair.',' An unexpectedly simple synthesis of Me2PH involving desulphuration of Me2P(S)P(S)Me2 by Bun3P in the presence of protic reagents (H,O alcohols etc.) has been reported.121 Pyrolysis of EtPCl at ca.930°C affords 1-phosphapropyne MeCEP as a minor product along with HCI PC13 and C2H4. Photoelectron data indicate that the compound is electronically similar to MeCEN.I2' Me2PC1 forms a borane adduct (47) which undergoes substitution reactions (Scheme 8). 123 The bis-borane adduct (48) is 0 Me,PCI + H,B . OC4H8 -Me,P-CI <Me2P '\PMe I I I BH.7 BH BH (47) Ii H .1 I1 /N\ Me,P-NH2 PMe, -Me2P I I I BH Reagents i NaNH,; ii LiR-Me,PCI-BH,; iii Ag,O Scheme 8 deprotonated by alkyl-lithium reagents at the bridging methylene group forming the ionic material (49). 124 The similar methylene-bridged species F5PCH2$F(NMe2)2 containing both hexa- and tetra-co-ordinated phosphates is obtained on treating F4PCH2PF4 with Me3SiNMe2.125 CH2 CH / \ BHj.OC,Hs ,CH2 LiR dI\ PMe -Me,P Me2P PMe,-.Li+ Me,P PMe, I I I I BH BH3 BH BH3 (48) (49) Several polyphosphine species were mentioned in last year's Report.The linear triphosphines (Me3Si),PP(R)P(SiMe3) (R = Me or Ph) from the reaction of (Me3Si),PLi-2THF with RPCI, rearrange at 120-1 30 "C to mixtures of (Me3Si),P *I9 H. Noth H. Reith and V. Thorn 2.anorg. Chem. 1979,458 219. '0. Dahl and S. Larsen J. Chem. Res. (S),1979 396. A. Trenkle and H. Vahrenkamp Z. Naturforsch. 1979,34b 642. N. P. C. Westwood H. W. Kroto J. F. Nixon and N. P. C. Simmons J.C.S. Dalton 1979 1405. 123 H. Schmidbaur and E. Weiss Angew. Chem. Internat. Edn. 1979 18,781. lZ4 H. Schmidbaur E. Weiss and B. Zimmergasser Angew.Chem. Internat. Edn. 1979,18,782. A. H. Cowley and R. C. Y. Lee Inorg. Chem. 1979 18,60. 76 F. A. Hart A. G. Massey P.G. Harrison and J.H. Holloway (Me,Si),PPh, a variety of substituted pentaphosphines and P9R3.'26 [2 + 13Cyclo-condensation has been employed for the synthesis of the diphosphasilirans (50) and the phosphadiarsirans (51). The stability of the latter which are obtained as a mixture of cis- and trans-' (more stable) isomers depends on the substituent on phosphorus. The ethyl-substituted derivative oligomerizes at a considerable rate even at -78 "C and cannot be isolated without some decomposition whereas the trans-isomer of the propyl derivative can be obtained in a pure state by low- temperature crystaIIization.127"28 R But/ 'But (50) R = Me or Ph (51) R=Et or Pr' The final product of the reaction of P2H4 with BuLi or LiPH is the cyclic polyphosphide Li3P7.3Solv (Soh = monoglyme or THF) containing the fluctional anion (52).Reaction with Me3SiC1 affords P,(SiMe,), which can be hydrolysed to P7H3.'29 He-I photoelectron data for the silylphosphine have been reported and a qualitative bonding model has been proposed. 130 The arsenic analogue A~~(siMe~)~ (isostructural with the phosphorus compound) and the silylundecaphosphine P ,(SiMeJ3 (53) have also been prepared by similar method^.'^' P-P \ SiMe Whether trigonal-bipyramidal or square-pyramidal geometry is adopted by quinquevalent phosphorus compounds is an old question. The steric bulk of R appears to be the deciding factor in compounds of the type PR(Ll2)(L2,) (R = H or Ph L12 L2,=chelating ligand).When R=H as in (54) the small size of the hydrogen atom allows almost perfect trigonal-bipyramidal geometry to be adopted but the replacement of hydrogen by phenyl results in a change to rectangular pyramidal geometry (55).132 126 W. Holderich and G. Fritz Z. anorg. Chem. 1979 457,127. 12' M.Baudler and H. Jongeblood Z. anorg. Chem. 1979 458,9. 12' M.Baudler and D. Haberrnann Angew. Chem. Znternat. Edn. 1979,18,877. 129 M. Baudler H. Ternberger W. Faber and J. Hahn Z. Naturforsch. 1979 34b,1690. 130 H. Bock B. Solouki G. Fritz and W. Holderich Z. anorg. Chem. 1979 458,53. *31 H.G. von Schnering D. Fenscke W. Honle M. Binnewies and K. Peters Angew. Chem.Znternat. Edn. 1979,18,679. 132 T. E. Clarke R. 0.Day and R. R. Holmes Inorg. Chem. 1979 18 1653 1660 1668. The Typical Elements 19 Ph H-rl& (54) E =NMe NH or 0 (55) Phosphazenes and Related Compounds.-As in recent years the chemistry of P-N compounds has once again been extremely fruitful. [Cl,P=NPCl,]CI reacts with H,C=C(CI)CN in the presence of AlCl to give CI3P=NPCl2 which on treatment with PPh3 affords Ph3P=NPC12.'33 Oxidation of the latter produces Ph3P=NP(0)C12 whose structure has been and which undergoes aminolysis with primary amines to compounds of the types C12P(0)N=PC12(NHR) (R =Me or But) Cl,P(O)N=PCl(NHMe), and Cl(Bu'NH)P(0)N=PC12(NHBut). No evidence for the formation of cyclic phosphazenes was ~btained.'~' Silylimino- phosphoranes have found some application as synthetic reagents.The reaction of R3P=NSiMe3 (R =Me NMe, or Ph) with phosphites P(OR') (R' =CH2CF3 or Ph) gives phosphazenophosphanes R3P=NP(OR')2.'36 Similarly addition of MeN=P(NMe2)3 to the silylated aminodiaminophosphorane (56) yields the acyclic diphosphazane betaine (57).'37 Me Me,Si-N Me,SiN N \/ \+ 'P=N-SiMe + MeN=P(NMe,) -P(NMe2)3 /p\N (Me,Si),N / (Me,Si),N (56) I SiMe (57) Treatment of N-silylated aminoiminophosphines with aluminium trihalides also gives acyclic zwitterions but above ca. room temperature decomposition to cyclic compounds occurs (Scheme 9).138*139 The structures of several four-membered (PN) ring compounds have been determined. [(PhNH)P(S)NPhI2 formed in moderate yield from p-P4S312 and aniline has the trans structure (58) and no evidence from the cis-isomer could be ~btained.'~' However both rings in [(PhNH)P,(NPh),],NPh formed in high yield 133 E.Fluck and R. Hosle 2.anorg. Chem. 1979,458 103. '34 A. F. Cameron I. R. Cameron and R. Keat Act0 Cryst. 1979 B35 1373. G. Bulloch and R. Keat Znorg. Chim.Am 1979 33 245. E. P. Flindt 2.anorg. Chem. 1978,441,97. I" M. Halstenberg R. Appel G. Hultner and J. V. Seyerl Z. Narurforsch. 1979,34b 1491. E. Niecke and R. Kroher Z. Naturforsch. 1979,34b 837. 139 S. Pohl Chem. Ber. 1979 112 3159. C. C. Chang R. C. Haltiwanger M. L. Thompson H. J. Chen and A. D. Norman Znorg. Chem. 1979 18 1899. 13' F. A. Hart A. G.Massey P. G.Harrison and J.H. Holloway (Me3Si),N-P=NR + AIX3 +Me,Si-N-P=NR + I I Me,Si -AIX X X(R) 1 ‘P’ P Me,Si -N8;)NR or RXX,<-Me,Si-N(;’)NR /\ ‘A1 A1 x’-‘x x/-\x Scheme 9 from PCl and aniline adopt the cis configuration (59).14*Treatment of cis-(ClPNBu‘)2 with Ph2PNMeLi gives a mixture of both isomers of [Ph2PN(Me)P=NButl2 which may be separated by fractional crystallization. No Ph Ph Ph N‘/ \ ,N\ 9s /p\N/p N s/ I I Ph Ph bh Ph (58) (59) isomerization occurs at room temperature in CHC13 but at ca. 60°C almost complete trans-cis isomerization takes place within three days. The reaction of (MeNPF,) with mono- and bis-silylated N,N’-dimethylurea yields the cubane-like compound (60).14 Cyclo-tri(X3-phosphazanes)halogenated at phosphorus (MeNPX) (X=C1 or Br) can be prepared by the reaction of silylamines such as (MeNSiMe2) or 14’ M.L. Thompson R. C. Haltiwanger and A. D. Thompson J.C.S. Chern. Cornm. 1979,647. D. A. Harvey R. Keat A. N. Keith K. W. Muir and D. S. Rycroft Inorg. Chim.Am 1979,34 L201. 143 K. Utvary and M. Kubjacek Monatsh. 1979 110 211. The Typical Elements 79 (Me,Si),NMe with excess PX3.144 Cyclization occurs on reaction of [Ph2P(CI)N=PCIPh2]CI with Me2Si(NMeSiMe3)2 affording (61),14' and also with Me3SiN=S=NSiMe3 and PC15 forming the thiotriazadiphosphorine ring (62) which gives the complex [N3P2SCI4]+SbCl- containing a planar ring on treatment with SbC15.'46 The chlorines attached to boron in the similar boron-containing heterocycle (63) are readily replaced by F NMe2 -SCH2CH2S- or catech01.~~' N N Ph,p/N%PPh2 C12P' *PC12 C12P5 >PC12 I1 II I I :I MeN ,NMe CI N /N HN,g,NH Si 's' -.L12 I Me2 1 1 c1 The second stage of amination of (PNCI2) takes place at the same phosphorus giving the geminal isomer of [P3N3C14(NHB~t)2]. 1-Hydrido-1 -alkylcyclo- 148 triphosphazenes N3P3CI4RH have been synthesized by the reaction of (PNC12) with alkyl Grignard reagents in the presence of [(Bu,P)CuI], followed by treatment with propan-2-01. 149 Ring-phosphorus exchange occurs between N3P3Ph4MeH and thiophosphonic anhydrides (Scheme 10). The mechanism of this reaction involves the insertion of an [RPS] unit into the ring involving opening and reclosure of the [N3P3] ring.15o Scheme 10 Unlike the reaction of perchloro-tri- and -tetra-phosphazene the corresponding fluoro-substituted analogues undergo only partial aminolysis with the replacement of only one halogen per phosphorus atom owing to the poor leaving ability of fluoride combined with the rather low nucleophilicity of amines.In contrast stronger nucleophiles e.g. CF3CH20Na PhONa and Me2NLi replace all fluorine~.~'~ The reaction of octachlorotetraphosphazene N4P4C18 with excess MeNH2 or of (primary amino)chlorophosphazenes such as N4P4C16(NHR)2 (R = alkyl) or N4P4C16(NHBu')(NHEt) with excess Me2NH leads to the formation of the 144 W. Zeiss and K. Barlos 2.Naturforsch. 1979 34b 423. 14' E. Fluck and U. Pachali Z. anorg. Chem. 1979,456 95. 146 S.Pohl 0.Petersen and H.W. Roesky Chem. Ber. 1979 112 1545. H. Binder and J. Palmtag Z. Naturforsch. 1979 34b 174. M.J. Begley D. B. Sowerby and T. J. Bamgboye J.C.S. Dalton 1979 1401. 149 H.R. Allcock and P. J. Harris J. Amer. Chem. SOC.,1979 101,6221. Is" J. Hogel and A. Schmidpeter 2.Naturforsch. 1979,34b 915. T. L. Evans and H. R. Allcock Inorg. Chem. 1979,18,2342. 14' 14' F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway bicyclic phosphazenes (64) in addition to the fully aminolysed derivatives.’52p153 In the structure of the methylamino-compound (64; R = Me) the two P-N bridge bonds are longer than the other P-N NHR NHR I I HRN-P-N&-NHR II\ I N NMeN NHR NHR I I Four- six- and eight-membered P-N ring systems have all been employed as ligands towards transition metals.The diazadiphosphetidine (Bu‘NPCI)~ reacts with [Fe2(CO),] [{RhCI(CO)2}2] [Mn2(CO)1,] and TiC14 to give complexes incorporat- ing the four-membered ring system as a bidentate P-donor. Both bridging and chelating behaviour e.g. (66) and (65) is 0b~erved.l~~ Hexafluorocyclo-triphosphazene reacts with Na[Fe(C0),(C5H5)] in THF to give after chromato- graphic separation a 10% yield of (67) which is readily photolysed to the air-stable complex (68).156 The cyclotetraphosphazene ring in the complex 15* S. S. Krishnamurthy K. Ramachandran A. C. Sau R. A. Shaw A. R. Murthy and M. Woods Inorg. Chem. 1979,18,2010. S. S. Krishnamurthy K. Ramachandran and M. Woods J. Chem. Res. (S),1979 92. lS4 T. Cameron R.E. Cordes and F. A. Jackman Acta Cryst. 1979 B35,980. L. S. Jenkins and G. R. Willey J.C.S. Dalton 1979 777. lS6 P. P. Greigger and H. R. Allcock 1 Amer. Chem. SOC.,1979 101 2492. The Typical Elements [N4P4Me8]PtC12.MeCN is co-ordinated to platinum through two antipodal ring nitrogen atoms with the ring in a ‘saddle’ conformation. On protonation in the complex [H2N4P4Me8]2’[PtC14]2- the ring assumes a distorted ‘chair’ conformation and the [PtCl4I2- anion forms a hydrogen-bonded bridge between parallel sets of phosphazene rings.’” Both complexes exhibit antitumour activity. Antimony and Bismuth.-A multitude of antimony compounds have been examined by X-ray crystallography. Antimony trichloride is isostructural with BiCl, and has a structure related to the PbCl,-type exhibited by several halides of bivalent tin and lead.The basic unit of the structure is a pyramidal SbCl unit with much longer contacts to five other chlorine atoms in a bkapped trigonal-prismatic arrangement (69).158The same unit is also present in methylammonium salts of the [Sb2C1g]3- anion in which adjacent anions are linked by chlorine bridges (70) giving six- co-ordinate antim~ny.’~~ Partial hydrolysis of the pyridinium salt in ethanol yields the oxochloro-anion (71).l6’ The square-pyramidal geometry present in this species is also exhibited by two of the antimony atoms of the tetranuclear oxochloro-anion (72). The other two have pseudo-trigonal-bipyramidalco-ordination.16’ -c1 61 - 4-(71) (72) The structures of four mixed antimony fluoride chlorides have been determined.Two Sb4C113F7162 have structures related to the fluorine- and Sb4C113.6F6.4,163 bridged tetranuclear structures of (SbFC14)4 and (SbF2C13)4 in which some of the axial chlorines have been replaced by fluorines. Crystals of Sb3FI1Cl4 are composed of [SbCl,]” cations and dinuclear fluorine-bridged [F4(F,Cl)Sb-F-Sb(F,Cl)F4]-Is’ J. P. O’Brien R. W. Allen and H. R. Allcock Inorg. Chem. 1979 18 2230. A. Lipka Acta Cryst. 1979 B35,3020. F. J. Kruger F. Zettler and A. Schmidt 2.anorg. Chem. 1979,449 136. M. Hall and D. B. Sowerby J.C.S. Chem. Cumm. 1979 1134. A. L. Rheingold A. G. Landers P. Dahlstrorn and J. Zubieta J.C.S. Chem. Comm. 1979 143. J. G. Ballard T. Birchall and D. R. Slim J.C.S.Dalton 1979 62. U. Miiller 2.anorg. Chem. 1979,454 75. 82 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway anions in which the positions cis to the bridging fluorine are statistically occupied by chlorine and fl~0rine.l~~ ‘Sb2F4Cl,’ is a mixed-valence ionic material containing [(F2C13Sb-F-SbFC13-F-SbCIf2F]’ cations and [(SbF2Cl,f2F]- anions asso- ciated by weak co-ordination of the terminal fluorine atoms of the anion to the tervalent antimony atoms in the ~afi0n.l~~ SbF and PF form a 1 3 adduct the vibrational spectra of which are consistent with the formulation [PF4][Sb3F16].’66 Antimony(v) chloride reacts with the methyl esters of oxalic acid and oxalic acid N-methylamides to give chelated six-co-ordinate tetrachloroantimony derivatives (Scheme ll).16’ The bridged dinuclear compound (73) is also obtained by the 0 1 ii It -SbCls -MeOC-q=O -SbCl J iv (73) R=HorMe Reagents i (MeOCO),; ii MeOCOCONMe,; iii 70 “C,vacuum; iv MeOCOCONHMe; v SbCl,; Vi 200 “C.vacuum Scheme 11 reaction of SbCI with MeOCOCONMe-Li’. The dinuclear phosphates (74) are produced similarly. 168 Reaction of tetrachloroantimony alkoxides or carboxylates with carboxylic acids afford the triply bridged dinuclear species (75)’ which react with acetylacetone to give the 0x0-bridged complex (76).169*170 (74) U. Miiller Z Naturforsch. 1979,34b 681. U. Miiller Z. anorg. Chern. 1978,447 171. G. S. H. Chen and J. Passmore J.C.S. Dalton 1979 1251. 167 M. Rossler W. Schwarz and A. Schmidt 2.Naturforsch. 1979,34b 398. M. Brauninger W. Schwarz and A. Schmidt Z. Naturforsch. 1979 34b 1703. 169 F. J. Koller W. Schwarz and A. Schmidt 2.Naturforsch. 1979 34b 563. 17” S. Blorsl W. Schwarz and A. Schmidt Z. Narurforsch. 1979 34b 1711. The Typical Elements 83 Both co-ordination types typical of Sbrrr pyramidal and pseudo-trigonal bipy- ramidal are present in the ternary antimony chalcogenides RbSb3S5.H20,171 K2Sb4S7.H20,172 and BaSb2Se4,174 cS2Sb~S13,~~~ but NH4SbS contains only the latter type.'75 In T14Bi2S5 the bismuth atom enjoys a distorted octahedral en~ir0nment.l~~ Diphenylantimony(II1) fluoride has been obtained by the reaction of SbF with [NH4I2[PhSiF5] and possess a fluorine-bridged chain structure (77) in which anti- mony has a pseudo-bridged bipyramidal geometry.177 Oxidation of Ph2SbF with bromine at -90 "C in CH2C12 yields the mixed halide Ph4Sb2Br5F which consists of Ph2SbBr2F and Ph2SbBr fragments linked by a strong fluorine bridge (78). The co-ordination polyhedra about antimony are distorted but are close to trigonal bipyramidal and octahedral Trigonal-bipyramidal geometry is also found in PhzSbBrCl2 and Ph2SbBr2C1,179 and in the carboxylates Ph4Sb02CH18' and Ph3Sb(02CMe)2,181 both of which contain unidentate carboxylato-groups. Br (77) Primary alkylstibines react with organochlorosilanes or HC1 to give pale green macromolecular species with a metallic sheen which analysis shows to be (RSb),. With iodine-containing reagents such as 12 ICI C14 and Me2AsI the same stibines afford the purple-black species (RSbIo.4)x.182 Tetrakis(trimethylsily1)distibene is produced by treating (Me,Si),Sb with three or fewer equivalents of B~'1.l~~ Substi-tution of antimony halides by LiNBu'(SiMe,) affords Bu'(Me,Si)NSbX (X = C1 or Br) compounds that eliminate Me,SiX at room temperature to give the diazadisti- betidines (79).ls4 The reaction of BiC1 with Li[02COMe] at -40 "C in methanol gives unstable BiCI[02COMe] which decomposes by a first-order reaction at 18 "C (ti = 535 s to BiC1(OMe)2 and C02.BiC1(OMe)2 and Bi(OMe)3 may be obtained by substitution of BiC1 using LiOMe in methanol at 0 0C.185 I7l K. Volk and H. Schafer Z. Naturforsch. 1979 34b 172. 172 B. Eisenrnann and H. Schafer 2.Nuturforsch. 1979 34b 172.173 K. Volk and H. Schafer 2.Naturforsch. 1979,34b 1637. G. Cordier and H. Schafer 2.Naturforsch. 1979 34b 1053. 175 K. Volk P. Bickert R. Kolmer and H. Schafer 2.Nuturforsch. 1979 34b 380. 176 M. Julien-Pouzol S. Jaulmes and P. Larvelle Acta Cryst. 1979 B35 1313. 177 S. P. Bone and D. B. Sowerby J.C.S. Dalton 1979 1430. M. J. Begley S. P. Bone and D. B. Sowerby J. Organometallic Chem. 1979 165 C47. 179 S. P. Bone and D. B. Sowerby J.C.S. Dalton 1979,715,718. S. P. Bone and D. B. Sowerby J. Chem. Res. (S) 1979 82. D. B. Sowerby J. Chem. Res. (S) 1979,80. 182 P. Choudhury M. F. El-Shazly C. Spring and A. L. Rheingold Inorg. Chem. 1979 18 543. lB3 H. J. Breunig and U. Breunig-Lynti Z. Nuturforsch. 1979 34b 926. N. Kuhn and 0.J. Scherer 2.Naturforsch.1979 34b 888. '" G. Gattow and R. Lingenfelder 2.anorg. Chem. 1978 447 131; 1979 448 115. 17' F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Pentagonal-pyramidal geometry is quite rare solitary examples having been observed previously for Sn** and Sb". MeBi(S2NEt2)2 also exhibits this geometry in the crystal uia intermolecular BiS-4 interactions (go) but is monomeric in solu- tion.*" Bi[Co(Co),] is formed from metallic bismuth and [Co,(CO),] or by BiCl and [Co(CO),]- and appears to possess a pyramidal BiCo ~keleton."~

ISSN:0260-1818    

DOI:10.1039/IC9797600059

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Part IV Groups VI VII and VIII By J H. Holloway 1 Introduction The valence-shell electron-pair repulsion theory has been widely used for predicting the shapes and variations in molecular geometries of a wide range of chemical species and has been eminently successful for compounds of the 'p-block' elements. However there are small but experimentally significant deviations in observed bond angles from those predicted in many compounds and already several attempts have been made to account for them. This year evidence based on correlations between bond angles and van der Waals radii of atoms in tetrahedral and trigonal-planar species has been interpreted to imply that generally bond angles are determined by steric effects (i.e.non-bonded atom repulsions).la Another suggestion derived from ab initio calculations on tetrahedral and related molecules is that there is a need for reinterpretation of the model in which emphasis is given to the total angular space required by bonding-pair and lone-pair orbitals.'b In another effort to generate a consistent model for various lone-pair effects in some main-group angular and trigonal-pyramidal compounds an analytical perturbation LCAO MO approach has been developed and used." If of course VSEPR theory is applied to non-metals and only oxygen and fluorine ligands are permitted almost complete structural predictions can be made. This year the structural chemistry of the fluorides and oxide fluorides of the non-metals has been reviewed against this background.ld C.Burschk and M. Wieber Z. Nuturforsch. 1979 34b 1037. '" G. Etzrodt R. Bose and G. Schmidt Chem. Ber. 1979 112 2574. (a)M. Charton J. Amer. Chem. Soc. 1979,101,7536; (6)A. Schmiedekamp D. W. J. Cruickshank S. Skaarup P. Pulay I. Hargittai and J. E. Boggs,ibid. p. 2002; (c) A. Shustorovich and P. A. Dobosh ibid. p. 4090; (d)K. Seppelt Angew. Chem. Internut. Edn. 1979 18 186. The Typical Elements 2 GroupVI Oxygen.-Production of singlet oxygen in aqueous solution is of importance for analytical and synthetic purposes and may also play a central role in biological disinfectant processes. Recent work indicates that the sodium or caesium salts of anthracene-9,lO-bisethanesulphonicacid are better substrates or traps for singlet oxygen than those known hitherto which are virtually insoluble in water or have other disadvantages.The new compounds are readily soluble in H20 and in buffer solutions are stable over a wide pH range and are not normally affected by oxidants such as OCl- and Hz02.2 Interest in the possibilities of obtaining chemical fuel from light-induced reactions has continued. Studies on oxygen evolution from water by metal dispersions are part of this in~estigation.~-~ The effects of both heat and light on the photodecomposition of water by platinum have been studied and it has been shown that hydrogen can be obtained thermally at 130-210°C. In sharp contrast with the H20 photolysis results obtained on illuminating platinized chlorophyll a no significant amounts of 0 were detected in the thermochemical Pt-H20 rea~tion.~ Similarly photo- assisted decomposition of H20 at the gas-solid interface on Ti02 has also produced little evidence of 0 evol~tion.~ In a review of the redox chemistry of dioxygen it has been pointed out that the energetics are heavily dependent upon mechanistic pathway and reactive substrate.Under acidic conditions the stable product is H202,but in alkaline media the final product is OH-. The redox chemistry of 02-,H202 and H02-is intimately connected with that for 0,and atom transfer and disproportionation reactions are an important part of their chemistry.6 New work in this area includes a study of the rates of reaction of 02-and H0 with Hz02(the Haber-Weiss reactions) as a function of pH in the range 0.5-10.0 and efforts have been made to minimize the role of metal impurities in the reactions.’ Electrical spectroscopic and chemical evidence has confirmed that superoxide ion efficiently reduces SO to dithionite ion in aprotic solvents thus providing convincing support for the conclusion that 02-is a significantly stronger and more effective reducing agent than dithionite ion.8 Last year some evidence was produced which indicated that the ultimate products in reactions of 02-with many molecules are the result of 02-decomposition products acting as oxidizing species or as very strong bases.It has now been suggested that experimental support for the assumed electron-transfer process between 02-and peroxides is lacking.’ ’M.Botsivali and D. E. Evans J.C.S. Chem. Cumm. 1979 1114. (a)J. Kiwi and M. Gratzel Angew. Chem. Internat. Edn. 1979 18 624; (b)J. Kiwi and M. Gratzel Chimia (Switz.) 1979,33,289;(c)K. Kalyanasundaram and M. Gratzel Angew. Chem. 1979,91,759; (d) J. M. Lehn J. P. Sauvage and R. Ziessel NouueauJ. Chim. 1979,3,423;(e)J. Kiwi and M. Gratzel J. Amer. Chem. SOC.,1979,101 7214. L. Galloway D. R. Fruge G. M. Haley A. B. Coddington and F. K. Fong J. Amer. Chem. Suc. 1979 101 229. H. Van Damme and W. K. Hall J. Amer. Chem. Suc. 1979,101,4373. J. P. Wilshire and D. T. Sawyer Accounts Chem. Res. 1979 12 105. ’J. Weinstein and B. H. J. Bielski J. Amer. Chem. Suc. 1979,101 58. * M. D. Stallings and D. T. Sawyer J.C.S.Chem. Comm. 1979 340. M. J. Gibian andT. Ungermann J. Amer. Chem. Soc. 1979,101 1291. E A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Direct measurement of 02-in aqueous solution is difficult because of the ion's short lifetime. Spin trapping with 4-hydroxy-2,2,6,6-tetramethyl-N-chloro-piperidine which reacts specifically with 02-to produce 4-hydroxy-2,2,6,6-tetra-methylpiperidinoxyl (a free radical stable for months at room temperature) has permitted the measurement of 02-steady-state concentrations as low as mol dm-3.'0 It is reasonable to expect that quite soon even more efficient spin trappers will be produced. Many studies of the electrochemistry of H202in aqueous media have been carried out but little is known of its redox chemistry in non-aqueous solutions.Investiga- tions of H202in non-aqueous (and alkaline aqueous) media of O2reduction with excess of protons in non-aqueous media and of the reaction of H202with OH-to yield 02-have produced novel information in this area." Interest in the binding between oxygen and transition metals in the proteins involved in oxygen transport and storage in living beings has provided impetus for further attempts to provide detailed descriptions of the metal-dioxygen bond in a variety of metal complexes. Special attention has again been paid to cobalt. The first successful application of resonance Raman spectroscopy to the determination of the solution 0-0 stretching frequency for a mononuclear cobalt dioxygen complex has been reported.'2a Em-.studies of cobalt(I1) Schiff -base complexes with dioxygen have shown that the Coo0angle lies in the region 115-120" and an X-ray study on the dioxygen adduct of aquo-[N,N'-(1,1,2,2-tetramethylethylene)bis-(3-methoxysalicylideniminato)]cobalt(~~)has also again confirmed this already consis- tent picture.'*' Potentiometric u.v.-visible and n.m.r. studies have provided con- vincing evidence for the formation of p-ethylenediamine bridges in addition to a p-peroxo-bridge in oxygenated Co" solutions containing ethylenediamine diethy- lenetriamine and triethylenetetramine. lZd A way of preventing the formation of a secondary bridge to the p-peroxo-bridge is to employ quinquedentate ligands in the complex. An X-ray study of one such compound p-peroxo-bis-{[l,l l-bis-(2- pyridyl)-2,6,lO-triazaundecane]cobalt(III)} tetraiodide trihydrate indicates that the dioxygen group is present as the peroxide ion.'2e Vaska's iridium compound was an early member of the class of reversible oxygen carriers and a new approach to the study of this complex has been the nuclear quadrupole resonance investigation of 170-'70 bonded to the compound.l3 This supplements X-ray data in revealing an inequivalence of charge distribution about the oxygens which may provide new insight into the mechanism of reversible oxygen bonding. New palladium dioxygen complexes having olefinic ligands have been prepared by the reaction of superoxide ion with dinuclear palladium complexes involving chloride bridge~.'~ The preparative method is simple and appears to be applicable lo A.Rigo E. Argese E. F. Orsega and P. Viglino Inorg. Chim. Acta 1979,35 161. l1 M. M. Morrison J. L. Roberts jun. and D. T. Sawyer Inorg. Chem. 1979,18 1971. l2 (a)T. Szymanski T. W. Cape R. P. Van Duyne and F. Basolo J.C.S. Chem. Comm. 1979,5; (b)R. L. Lancashire,T. D. Smith and J. R. Pilbrow J.C.S.Dalton 1979,66; (c)B. T. Huie R. M. Leyden and W. P. Schaefer Inorg. Chem. 1979,18,125;(d)M. Crawford,S. A. Bedell R. I. Patel L. W. Young and R. Nakon ibid. p. 2075; (e)J. H. Timmons A. Clearfield A. E. Martell and R. H. Niswander ibid. p. 1042. l3 0.Lumpkin W. T. Dixon and J. Poser Inorg. Chem. 1979,18,982. '* H. Suzuki K. Mizutanc Y. Moro-oka and T. Ikawa J. Amer. Chem. SOC. 1979 101 748. The Typical Elements for other transition metals.Another novel dioxygen binder is the iron(I1) 'homolo- gous cap' porphyrin [Fe(HmCap)(l-MeIm)] which has been shown to be capable of weakly binding a second 1-MeIm molecule. The new complex can also bind dioxygen reversibly without displacing the additional 1igand.l' Although the occur- rence of managenese(II1) in biological redox reactions has become increasingly apparent it is difficult to study. This year reactions of 02-with [Mn"'(edta)]- [Mn"(edta)12- and [Mn"'(cydta)]-(cydta-= diaminocylclohexane-N,N,N',N'-tetra-acetic acid) in aqueous and non-aqueous solvents have been studied and the molecular and crystal structure of KMn(edta).2H20 has been determined. l6 Moving from biological to geological systems geophysical and geochemical conditions during the formation of fluorites can be obtained by studying trapped 0,-centres in the structure.The ion has recently been observed for the first time in an alkaline-earth fluoride and e.p.r. and ENDOR results have shown that the 0,-is associated with a sodium and a calcium neighbour and that the centre has a motional degree of freedom." An interesting development in the chemistry of ozonides is that their reaction with catalytic amounts of SbCl or CIS0,H in methylene chloride seems to be a good general method for the formation of tetraoxans (Scheme l).'* H H a R' = R2= Ph; b R' = R2= n-pentyl; c R' = Ph R2= n-pentyl la + 2a; lb + 2b; lc -P 2a+2b+2c Scheme 1 The chemical and biological importance of water has made it the focus for theoretical considerations for many years.Recent work has included the con- struction of an intermolecular potential function representative of minimal basis set ab initio calculations for the water dimerlg" which has allowed a thorough investiga- tion of the basis set dependence of computer simulation results for liquid water.lgb Our understanding of the physical properties of water may be helped by the discovery of hydrogen-bonded six-membered and five-membered rings of H20 molecules in a-cyclodextrin.6H20. It has been suggested that these structures might explain the flickering cluster structure of bulk water.lgc Work on the i.r. spectroscopy ofhydrates mentioned last year has been extended and groups of bands in the i.r.spectra of SF6-water clathrates have been interpreted J. R. Budge P. E. Ellis jun. R. D. Jones J. E. Linard F. Basolo J. E. Baldwin and R. L. Dyer J. Amer. Chem. SOC.,1979,101,4760. '' J. Stein J. P. Fackler jun. G. J. McClune J. A. Fee and L. T. Chan Inorg. Chem. 1979 18 3511. H. Bill J. Chem. Phys. 1979 70 277. M. Miura and M. Nojima J.C.S. Chem. Comm. 1979,467. l9 (a) W. L. Jorgensen J. Amer. Chem. SOC.,1979,101,2011; (6) W. L. Jorgensen ibid. p. 2016; (c) W. Daenger Nature 1979 219 343. F. A. Hart A. G.Massey P. G.Harrison andJ. H. Holloway in terms of the presence of three crystallographically different water molecules in the structure.2oa Enthalpies of formation of SF6 and CF3Br deuterates differ from those of the equivalent hydrates.20b Phase diagram studies on the R4NF- and R4NCl-H20 systems indicate that hydrates are formed.20C Hydroxonium ions which received considerable attention last year contain a single central atom.The synthesis of the first examples of peroxonium salts [H3O2]+[Sb2F1 [H302]'[SbF6]- and [H3O2]+[AsF6]- have now made possible the study of the influence of protonation on the strength of the bond between two 'central' atoms in the H302+ cation. The salts were prepared by reaction of anhydrous HF-Lewis acid solutions on H202 and were characterized by vibrational and n.m.r. spectroscopy. No evidence for double protonation (i.e. [H4O2I2+)was found and when SbF was used in a two-fold excess the peroxonium salt of the polyanion ([H302]'[Sb2Fll]-) resulted. The similarity of the spectra and the computed force fields of [H,OOH]' suggest that it is isostructural with H2NOH which has C,symmetry.21a The influence of stepwise hydration on the kinetics of proton transfer from H30+ to ammonia and a variety of oxygen bases has been studied in flowihg H20-hydrogen or H20-helium plasmas at low pressures and room temperature.Rate constants were measured for the reactions of the various bases with H30+.H20 H30.(HzO)2 and H30+.(H20)3. The reactions were observed to proceed according to the general equation H30+.(H20),+ B + BH'.(H20) + (n-rn + 1)H20 (1) (Ocrncn) Previously found in some twelve compounds the [Hs02]+ ion occurs in [Et4N]3(Hs02)[Mo2C18H][MoCI,0(H20)], with an 0-.H. -SO distance 0.07 8 shorter than previously reported in this ion and at 2.34( 1)A it is comparable with the shortest bonds of this type which are known.Clearly with such a short 0.-.H. -0 distance it is of interest to determine the 0-H distances and efforts are being made to grow crystals for neutron diffraction investigation.21' Another very short hydro- gen bond (the shortest observed so far for water) has been found in a mono- hydrated hydroxide (or bihydroxide) ion in the mixed salt Na2[Et3MeN] [Cr{PhC(S)=N(0)},].~NaH302- 18H20. This is the first time that this simplest hydr- oxide hydrate has been isolated and structurally characterized and interesting comparison can be made with the isoelectronic bifluoride ion HF2- especially since F-and OH-ions have similar effective ionic radii.The F-F distances in the bifluoride ion in a variety of its salts compare well with the 0-0 distance of 2.29(2) A found in the new anion.21d Following the discovery of and work on the kinetics and thermal decomposition of SFsOOOSFs last year a new investigation has shown that in the presence of a sufficiently high pressure of O2 the decomposition between 5 and 25°C yields *' (a)V. V. Dyrkheev D. Yu. Stupin and V. N. Tezikov Zhur. strukt. Khim. 1979,20 172; (b)D. Yu. Stupin V. N. Tezikov A. P. Seleznev and V. V. Dyrkheev Izvest. Vyssh. Uchebn. Zaved. Khim. khim. Tekhnol. 1978 21 979; (c) Yu. A. Dyadin and I. S. Terekhova Izvest. sibirsk. Otdel. Akad. Nauk S.S.S.R. Ser. khim. Nauk 1978,6 39. *' (a)K. 0.Christe W. W. Wilson and E. C. Curtis Inorg. Chem.,1979,18,2578; (b)D.K. Bohme G.I. Mackay and S. D. Tanner J. Amer. Chem. SOC.,1979,101,3724; (c)A. Bin0 and F. A. Cotton ibid. p. 4150; (d)K. Abu-Dari K. N. Raymond and D. P. Freyberg ibid. p. 3688. The Typical Elements SF502SF5 and 0,. The reaction is homogeneous and it has been estimated that the dissociation energy of SF50-02SF5is 105*4 KJ mo1-'.22 The photoelectron and the i.r. spectrum of FzO dissolved in liquid nitrogenz3' have been observed. Direct evidence for the production of O,F from the thermal decomposition of O,'[AsF,]-has been obtained by the measurement of the U.V.absorption spectrum of the decomposition products. A second-order decay was indi~ated.'~' Hypofluorous acid HOF behaves as an oxygenating or hydroxylating agent.In all reactions of this type it may be regarded as a donor of atomic oxygen or its conjugate acid OH'. It has now been established by "0 tracer experiments of the reactions of HOF with H,O and with aqueous HS0,-and [Cr(NH3)5N3]2' that HOF does in fact transfer its oxygen directly to aqueous Sulphur.-Information about sulph~r-selenium~~" and sulphur-tellurium25' mixed crystals has been obtained from Raman and Mossbauer spectroscopic data. The Raman results show that Se,SS- mixed crystals must contain entities with homonuclear Se-Se bonds but are not the Se8 moiety.25" Separation of S12,a-SlS and Szofrom liquid Ss has been accomplished by flotation (in the case of S,,) and fractional crystallization from CSz (in the cases of SlSand S2,,). Evidence for larger rings S (n>20) was also found.This means that liquid sulphur contains rings both Figure 1 Structure of [(S71)zI]3' and two interacting [SbFJ anions (Reproduced from J.C.S. Chem. Comm. 1979 901) 22 J. Czarnowski and H. J. Schumacker Internat. J. Chem. Kinetics 1979 11 613. 23 (a)W.von Niessen J. Electron Spectroscopy Rel. Phenom. 1979,17,'197; (b)T. D. Kolomiitsova V. A. Kondaurov and D. N. Shchepkin Optika i Spektroskopiya 1979,47 79; (c)R. D. Coombe and R. K. Horne J. Phys. Chem. 1979,83 2805. 24 E. H. Appelman R. C. Thompson and A. G. Engelkemeir Znorg.Chem. 1979,18,909. " (a)H. H. Eysel and S. Sunder Znorg. Chem. 1979,18,2626; (6)C.S. Kim and P. Boolchand Phys. Rev. (B), 1979,19,3187. F. A. Hart A. G.Massey P. G.Harrison and J.H. Holloway smaller and larger than Ss (ix.S, n = 6,7,12,18,20 or >20). However there is still no evidence for the presence of S9 Sl0,and other medium-sized rings.26 The novel cation [(S7I),II3+,which consists of two [S71]' fragments joined by a linear S-I-S bond (Figure l) has been prepared in essentially quantitative yield as S1413(SbF6)3.2A~F3 by the reaction of Ss 12 and SbF in the appropriate ratios in AsF~.~~ The importance of S22-ligands for the stabilization of unusual co-ordination compounds of the transition metals is evident in the X-ray structure of the complex anion [MO~(NO)~S~~]~- (Figure 2) in the compound (NH4)4[Mo4(N0)4S13].2H20. 5 f Figure 2 Structure of the [MO~(NO)~S~~]~-anion (Reproduced by permission from Angew.Chem. Internat. Edn. 1979 18,168) The molecule contains sulphur in five different bonding states. These include sulphur in the form of SZ2-ligands four of which are co-ordinated both end-on and side-on to two different metal atoms.28 Mechanistic interpretation of the degrada- tion of one S,-ring in [Pt(S,)3]2- by stoicheiometric amounts of nucleophiles such as sulphite arsenite sulphide hydroxide and triphenylphosphine have been put forward as shown in equation (2).29With excess of nucleophile all the sulphurs are 26 R. Steudel and H.-J. Mausle Angew. Chem. Internat. Edn. 1979,18,152. '' J. Passmore G. Sutherland and P. S. White J.C.S. Chem. Comm. 1979,901. 28 A. Muller W. Eltzner and N. Mohan Angew. Chem. Internat. Edn. 1979,18,168. 29 M.Schmidt and G. G. Hoffrnann Z. anorg. Chem. 1979,452,112. The Typical Elements 91 removed except in the triphenylphosphine case when the S4-anion remains [see equation (3)].,' [Pt(S5),I2+4PPh3 -@W"hAJ2+) +Ss2-+Ss2-Ph3P\ Pt s-s Ph,P' \s-8 +PPh3+SPPh3 (3) The first two-co-ordinate sulphur dication [(Me2N)2S]2+ has been prepared by treatment of (Me2N)2SF2 with fluoride ion acceptors such as PF5 AsFs or BF3 in S02.30a The electronic structures of S42+30b and Sg2+30c have been investigated using a MO theoretical treatment and comparisons have been made with the related selenium and tellurium species. Molecular beam electric deflection experiments carried out on the dimers and high polymers of H2S and MeSH show that they are polar as expected for linear hydrogen-bonded structures while data for trimers and high polymers are consistent with them having cyclic structure~.~' Reactions of H2S with BX3 and with.BX3- NR,SH (X=Cl Br or Et R=Me or Et) have been studied and the products identified.The Raman spectrum of the unstable H2S.BC13 adduct was recorded at low temperature. The combination of H2S with B(SEt) and NR4SH in up to 2 :1 molar ratio produces cyclic thioborates (NR4)2-,[B3S3(SH)4-y(SR)y+l-xx] (x = 0 or 1 y = 0 1 or 2).32 However perhaps the most interesting reaction of hydrogen sulphide this year has been its reaction with iodine which gives rise to HSI and HI in accordance with equation (4). The heat of formation of HSI is 41.8 f2.80 kJ mol-'. I,+H*S + HSI+HI (4) Presumably the reason why this reaction was not tried earlier was that HSI might be expected to disproportionate to H2S2 and I,.By carrying out the reaction at high temperature in the gas phase condensation has been avoided and HSI The structure and bonding in cyclic sulphur-nitrogen compounds in which sulphur is two- three- or four-co-ordinate has been authoritatively reviewed and discussed. Attention has been drawn to the fact that it is possible to correlate co-ordination number and bond length in certain compounds containing three- and four-co-ordinate Last year the novel sulphur-nitrogen anion S3N3- was prepared and preliminary X-ray structural data were published. Detailed results now show that the anion is a six-membered essentially planar ring and vibrational spectra have been assigned and discussed on the basis of D3,,symmetry.Ab initio Hartree-Fock-Slater SCF calculations have been carried out and show that the planar configuration has the lowest energy.35 30 (a)A. H. Cowley D. J. Pagel and M. L. Walker J.C.S. Chem. Comm. 1979,965; (b) K. Tanaka T. Yamabe H. Terama-e and K. Fukui Inorg. Chem. 1979 18 3591; (c) K. Tanaka T. Yamabe H. Terama-e and K. Fukui Nouueau J. Chim. 1979,3 379. 31 J. A. Odutola R. Viswanathan andT. R. Dyke J. Amer. Chem. SOC.,1979,101,4787. 32 G. Heller and W. Eysenbach Znorg. Chem. 1979 18 380. 33 R. J. Hwang and S. W. Benson J. Amer. Chem. SOC.,1979,101,2615. 34 H. W. Roesky Angew. Chem. Internat. Edn. 1979 18 91. 35 J. Bojes T. Chivers W. G. Laidlaw and M. Trsic J. Amer.Chem. SOC.,1979 101 4517. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway The prototype 'non-metallic metal' (SN), continues to be of interest. The predominant species in the vapour has been shown to be tetrameric (SN), but the isomeric form of this entity has not been established and both linear and cyclic forms have been suggested. Molecular beam electric deflection analysis indicates that the tetramer is non-p~lar.~~~ Although this result excludes several structural forms the exact nature of the isomer still remains a matter for debate. About a year ago it was shown that the reaction of solid S4N4 with bromine vapour yields a brominated derivative of (SN), (SNBro,,), while reaction with bromine liquid gives S4N3+Br3-. The crystal structure of S4N3+Br3- has now shown that the S4N3+ ring is essentially planar and that structure consists of stacks of alternating cations and anions.It has been suggested that the new information provides an insight into the arrangement of atoms in (SNBr0,4)x.366 In the meantime further investigations of reactions of S4N4 indicate that the products of reaction are very much dependent on the conditions used. Interaction of S4N4 with bromine in CS2 solution results in the formation of S4N3Br3 S4N,Br and a novel ionic compound CS,N2Br which appears to have the structure (3) although other possibilities (4) and (9,cannot be ruled (3) (4) Chlorination of S4N4 has produced the new thiazyl chloride N4S4Cl2. The fluoro-analogue has been prepared by the reaction of N4S4C12 with NaF.Both are preliminary intermediates in the chlorination and fluorination of S4N4.36d Reaction of the imido-bis-(sulphuryl chloride) salt of S4N3+ with SbCls has given rise to the compound [S,N3]+[SbC15N(S02C1)2]-.36' Mass spectrometric examination of the pyrolysis products of S,N when the vapour is passed over quartz and silver wool at temperatures between 80400 "C has provided direct evidence for S3N3 and SN The acyclic S4N4 isomer postulated by other was not detected in the products but the results confirm established methods for the synthesis of S2N2 and (SN),.37" Thermal decomposition of (Ph3P)2NfS,N5- in acetonitrile leads to the corresponding salts of the S3N3- and S,N- anions. The crystal structure of (Ph3P)2N+S4N- which contains the first example of an acyclic binary sulphur-nitrogen anion to be structurally characterized (Figure 3) has been obtained.The anion is a planar cis-trans chain with nitrogen in the middle of four sulphur The synthesis and structure of (a)R. R. Cavanagh R. S. Altman D. R. Herschbach and W. Klemperer J. Amer. Chem. SOC. 1979 101,4734;(b)J. J. Mayerle G. Wolmershauser and G. B. Street Znorg. Chem. 1979,18 1161; (c)G. Wolmershauser G. B. Street and R. D. Smith ibid.,p. 383; (d)L. Zboiilovi and P. Gebauer 2.anorg. Chem. 1979,448,5;(e)R. C. Paul P. Kapoor R. Kapoor and R. dev Verma J. Znorg. Nuclear Chem. 1979 41 801. 37 (a)R. D. Smith J.C.S. Dalton 1979 478; (b)E. J. Louis A. G.MacDiarmid A. F. Garito and A. J. Heeger J.C.S. Chem. Comm. 1976,425.38 T. Chivers and R. T. Oakley J.C.S. Chem. Comm. 1979 752. The Typical Elements Figure 3 Srrucrure of rhe S4N-anion in (PPh3)2N+S4N-(Reproduced from J.C.S. Chem. Comm. 1979,752) S4N5+Cl- was reported in a preliminary communication last year. A recent paper39" includes synthetic details and spectroscopic characterization of three salts of the bicyclic cation S4N5+F- S4Ns+[SbC1,]- and S4N5+Cl-. Ab initio Hartree-Fock-Slater SCF calculations of the ground-state electronic structures of S4N5+ and S4N5-have been carried out in order to assess the effect of introducing an N- or N' species into the S4N4framework. These show that the introduction of bridging N- destroys one of the transannular S-S bonds and weakens the S-N framework bonds. In S4N5+ there are no S-..Sbonds as might be expected following the loss of two electrons from the S4N5- anion.39a An X-ray crystallographic study of the new bicyclic cation [S3N5Me2CO]' which is analogous to the S4N5+ cation shows that it contains a three-membered ring of S atoms which is bridged by three nitrogen atoms and a urethane group.The cation which occurs in the compund [S3N5Me2CO]+Cl- was prepared by the reaction of S,N3C13 with Me3SiNMeC(0)MeSiMe3 in CC14.39b Following the preparation of S5N6 last year this (6) and other interesting novel sulphur-nitrogen basket-like ions (7) and molecules [(8) and (9)] have been Me Me Me Me synthesized by reaction of S3N3C13 with Me2S(NSiMe3)2 or N(SnMe3),. The struc- ture of S5N6 has been confirmed by an X-ray single-crystal structure determination and a similar structure for (9)has been assumed on the basis of the similarity of their i.r.Reaction of S4N,C1 with thiacyclopentane S,S-bis(tri-methylsilylimide) has resulted in the formation of a 'handled' basket-like molecule (lo) the first spirocyclic l'h6-thiacyclopentane derivative of a sulphur-nitrogen compound the structure of which has been solved by X-ray 39 (a) T. Chivers L. Fielding W. G. Laidlaw and M. Trsic Znorg. Chem. 1979 18 3379; (b)H. W. Roesky T. Miiller and E. Rodek J.C.S. Chem. Comm. 1979,439. 40 (a)H. W. Roesky M. N. S. Rao T. Nakajima and W. S. Sheldrick Chem. Ber. 1979,79,3531; (b)H. W. Roesky C. Graf M. N. S. Rao B. Krebs and G. Henkel Angew. Chem. Internat. Edn.,1979.18 780; (c) H.W. Roesky M. Diehl B. Krebs and M. Hein Z. Nuturforsch. 1979,34b 814. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway s s IkS,4 N\s/N (10) Ten-membered and twelve-membered sulphur-nitrogen rings containing two-co- ordinate sulphur have been prepared by the reaction of SS[N(SnMe3)SO2CF3I2 with SC12 and S2C12 respectively. The starting material and the related compounds SO[N(SnMe3)SO2CF3I2 and S02[N(SnMe3)S02CF312 can be prepared by the reac- tion of N,N-bis(trimethylstanny1)trifluoromethanesulphonamidewith S2C12 SOCl2 and S02C12 respe~tively.~~“ The first structural investigations of cyclodiaza-A 6-thianes have been made and these show that the geometry of the S2N2 ring is strongly dependent upon the nature of the attached ligands.Thus in (11)the S2N2skeleton is non-planar but in (12)the ring is completely flat.41 CMe SiMe C2FsN NCMe Me,SiN I 0 \s/ \< “s/N\g C2FSN// ‘N’ I \\ NC2FS o//\N/ I \\N-SiMe CMe SiMe (11) (12) Reactions of the tetrasulphur tetranitride derivative S4N402 have produced exceedingly interesting chemistry recently. Nucleophilic substitution reactions in cyclic sulphur-nitrogen chemistry have been a matter of speculation until the synthesis of [S4N4020Me]-Na’ from the reaction of S4N402 with NaOMe. The X-ray crystal structure of the phenyl phosphonium salt shows that the S4N4 skeleton can be regarded as consisting of two five-membered rings with a weak central S-S bond (Figure 4).42“ The ring is of further interest because it contains two- three and four-co-ordinate sulphur.Figure 4 Structure of the [S4N402(OMe)]-ion in the crystal (Reproduced by permission from Angew. Chem. Internat. Edn. 1979 18,415) 41 F. M. Tesky R. Mews and B. Krebs Angew. Chem. Internat. Edn. 1979 18 235. ‘* (a)H. W. Roesky M. Witt B. Krebs and H. J. Korte Angew. Chem. Internat. Edn. 1979,18,415; (b) H. W. Roesky M. Witt M. Diehl J. W. Bats and H. Fuess Chem. Ber. 1979 79 1372; (c) H. W. Roesky M. Witt J. W. Bats H. Fuess F. J. Balti Calleji and F. Ania 2.anorg. Chem. 1979,458,225. The Typical Elements Reaction of S&O with substituted silyl amines or tris(trimethylstannyl)amine yields six-membered rings which are the first examples of ring systems in which the sulphur atoms are found with the formal oxidation states 2 4 and 6 (Scheme 2).N(SiMe,) SiMe (Me,Si),NMe Me,SiN=S=NSiMe, ‘z ZN(SnMe,) \ FSO,N=S=O SnMe Scbeme 2 These can be made by the action of silyl- and stannyl-sulphur di-imide on N-sulphinylfluorosulphonamide.42b An eight-membered ring can be prepared by reaction of S4N40 with N(SnMe3)3.42b*C Structures of both the six-42b and eight- membered42c ring compounds have been obtained. Diphenylsulphanuric chloride (NS0)3Ph2Cl has been shown to be much less prone to ring cleavage upon nucleophilic substitution than sulphanuric chloride (Scheme 3).43 -B+H Mc3N-MeOH Scbeme 3 43 T. J. Maricich and M. H. Khalil Inorg. Chern. 1979 18 912. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Esters of the unknown acid (NSOH), with formulae (NSOCH2CHC1CH2C1), (NSOCH2CHCIEt), and (NSOC6H&l) have been prepared by the reaction of (NSCl) with ethyloxiran chloromethyloxiran and 7-oxabicyclo[4.l.0]heptane re~pectively.~~ Reaction of bis(trimethylsily1)sulphur di-imide with PClS has produced the novel pentachlorothiatriazadiphosphorine(13) which with SbC15 yields the complex [N,P&14S]'[SbC16]- (14) containing a planar six-membered sulphur-nitrogen-phosphorus ring.4s c1 I The NSO- anion has been prepared for the first time by reaction of potassium t-butoxide with sulphinylaminotrimethylsilanein tetrahydrofuran [equation (S)].KOBu'+ Me3SiNSO -+ KNSO + Me3SiOBu' (5) The cream-coloured potassium thiazate melts to an orange liquid at 190"C explodes on ignition and ignites in contact with water.It forms a complex with 18-cr0wn-6.~~ The simplest sulphur-nitrogen-fluorine compound NSF was first made twenty years ago. At room temperature it is unstable. However it has now been demon- strated that stabilization of the molecule is possible when it is incorporated as a ligand in transition-metal complexes of the form [M(NSF),][AsF6] (M = Co or Ni). The complexes can be obtained in close to quantitative yield by reaction of the hexafluoroarsenates with an excess of NSF in liquid SO below -20°C. The structure of the cobalt compound shows that the Co is octahedrally co-ordinated; the NSF angle is essentially unchanged but the S-N bond distance is the shortest so far rec~rded.~' The molecule NSF has adjacent polar and strong triple bonds.For similar systems when the central atom is a first-row element large stretch-stretch inter-action constants are found. In the NSF (and SPF,) molecules i.r. spectra and band contour analysis have shown that the interaction constants are comparatively small presumably because a change in the bond length of the polar bond has less influence on the strength of the bond.^^ Reaction of NSF with LiN(SiR3)CR3 has produced three-co-ordinate sulphur(1v)-nitrogen compounds (15) and ( 16).49a Three-co-ordinate sulphur 44 G. G. Alange A. J. Banister and B. Bell J. Inoig. Nuclear Chem. 1979 41 1421. 45 S. Pohl 0.Petersen and H. W. Roesky Chem. Ber. 1979,112 1545. 46 D. A. Armitage and J. C. Brand J.C.S. Chem. Comm.1979,1078. 47 B. Buss P. G.Jones R. Mews M. Noltemeyer and G. M. Sheldrick Angew. Chem. Internat. Edn. 1979 18 231. 48 F. Koniger C. E. Blom and A. Miiller J. Mol. Spectroscopy 1979.77 76. 49 (a)F.-M. Tesky R. Mews and 0.Glemser Z. anorg. Chem. 1979,452,103;(b)R. Mews andH. Henle J. Fluorine Chem. 1979,14,495; (c) R. Mews and H. C. Braeuer 2.anorg. Chem. 1978,447,126; (d) H. J. Krannich and W. Sundermeyer ibid. 1979 450 45; (e) A. Semmoud and P. Vast Rev. Chim. minirale 1979 16 80. The Typical Elements R3CN ,NSiR3 R3CN ,NCR3 ‘i’ 2’ NCR NCH3 cations [R2NSO]+ and [R,NS=NR,]’ are also formed when four-co-ordinate neu- tral dialkylaminosulphur(1v) oxide fluorides R,NS(O)F and amino-imino sulphur(1v) fluorides R,NS(=NR,)F react with Lewis acids such as AsF5 SbF5 or BF3.Similar reactions with five-co-ordinate aminosulphur(1v) trifluorides R2NSF3 and aminosulphur(v1) oxide trifluorides R,NS(O)F, give four-co-ordinate sulphur Fluoro-Lewis acids and transition-metal Lewis acids such as [M(CO)J make the weak acid HNSOF act as a base to produce nitrogen-bonded complexes such as FSSb.HNSOF2 (17) and [M(CO)5HNSOF2]+[AsF6]-.49‘ Reactions of OCFBr with Hg(NSO) or OSFCl with Hg(NCO) both produce FSO(NC0) (18) and Hg(NSOF,) with OSFCl gives FSO(NSOF,) (19).49dThe i.r. spectrum of H,NSO,F and its mercury salt HgNS02F have been obtained and compared with those of related O=C=N ON0 \ /F Ts’ 09 /.. / \ F FF Reaction of pentafluoroethyliminosulphur difluoride with amines is recognized as a convenient route to five-membered heterocycles.Diols react similarly. However it has been shown that reaction of the difluoride with 2-mercaptoethanol results in the formation of a six-membered ring [equation (6)].” NaF CF3CF2N=SF2 + HSCH2CH2OH CF3 C ”>+ CF3C(0)NH2 (6) ‘0 Over the past several years i.r. spectroscopic and X-ray studies have suggested that the SIVNSV1 moiety in N-sulphinosulphimides is conjugated. Now localized MO calculations using the semi-empirical CNDO/2 method indicate the presence of a three-centre d-p-d rr-bond across the three atoms strongly concentrated on the central nitrogen atom. This clearly supports the empirical data.51 Sulphur dioxide is a versatile ligand which produces a variety of complexes. Examples of oxygen-to-metal SO2co-ordination are not known for transition metals but ten years ago it was observed for the Lewis acid SbF5.This year Raman 0. Glemser and J. M. Shreeve Inorg. Chem. 1979 18 213. G. NBray-Szabo and A. Kucsman J.C.S. Dalton 1979 89 1. 98 E A. Hart A. G.Massey P. G.Harrison and J. H. Holloway spectroscopic evidence for the donor-acceptor adducts S02.SbF5 and S02.A~F5,52a has been obtaind and novel linkage isomerism of SO2to the metal has been detected in the solid-state photolysis of [RU(NH,).,C~(SO,)]C~.~*~ A detailed examination has been made of SO complexes with respect to possible correlations involving their physicochemical properties and their possible co-ordination geometries (Figure 5) M-S /p O\,/p M-0 O h4q 0 NO M/\M \s/ k0 Z = metal ligand or main-group atom pyramidal coplanar bridging 0-bonded 0,s-bonded Figure 5 Co-ordination geometries of SOz complexes (Reproduced by permission from Inorg.Chem. 1979 18 182) and for 1:1complexes it has been shown that general correlations of geometry with S-0 i.r. stretching frequencies reversibility of SO binding and tendency of a complex to undergo the sulphato reaction can be made.52c The occurrence of [SO,]-radical ion and of ion pairs containing a metal ion and [SO2]-has been demonstrated for solutions of metals in non-aqueous solvents containing SO,. A correlation has been established between dielectric constant donor number and the reactivity of metals in solvents containing SO,. It has been postulated that the blue and brown colours in such solutions can be accounted for by equation (7).53 M +xSO~+ M"+ +x[SOJ $ [M"'.SO,-]+ (X -l)[SO,]-(7) brown blue Molecular weight determinations and Raman spectra indicate that addvcts of AsF3 with SO with ratios of 1:3 up to 2 :1 can be prepared although the SO is readily Reaction of SO with cyanogen has been shown by X-ray structure analysis to give 1,2,3-oxathiazolo[4,5-d][l,2,3]oxathiazole 2,2,5,5-tetroxide (20) .546 The dithionite ion [(S02),S0,*]-is the product of the reaction of superoxide ion with SO, which indicates the superior reducing properties of 02-.8 E.s.r.spectra of radicals derived from dithionate tetrathionate and thiosulphate anions have been '* (a)G. S. H. Chen and J.Passmore J.C.S.Dalton 1979 1257; (b)D. A. Johnson and V. C. Dew Inorg. Chem. 1979 18 3273; (c) G. J. Kubas ibid. p. 182. " W. D. Harrison J. B. Gill and D. C. Goodall J.C.S. Dalton 1979 847. 54 (a)J. Touzin and L. Mitacek Coll. Czech. Chem.Comm.,1979,44,1521;(6)H. W. Roesky N. Amin G. Remners A. Gieren U. Riemann and B. Dederer Angew. Chem. Internat. Edn. 1979,18 223. The Typical Elements 99 investigated.” The formation of peroxodisulphate [S,O,]’-in mixed aqueous solu- tions of HzS04 (NH4),S04 and NH4F has been st~died.’~ A comprehensive study of the ion-molecule reactions in the sulphuryl halides S02C12 S02F2 and S0,CIF has been made. In SO,Cl the most abundant primary ion is C1- which reacts with S02C1 to give the secondary ions C13- and SO,Cl-.” Raman spectroscopic examination of the reaction products of SOF2 with AsF5 and SbF5 show that 1:1oxygen-bridged adducts are formed.With S02F2 however only the AsF5 adduct is formed. This indicates a reversal of the usual Lewis acidities of AsF5 and SbF5.52n A vibrational spectroscopic examination of solid and liquid HS0,F and a Raman spectroscopic study of HS0,F in the gaseous state have been made and the results have been interpreted as suggestive of the acid existing in the form of cyclic dimers in the gas and as infinite chains in the solid. It appears that both cyclic dimers and open chains co-exist in the The ‘ephemeral oxidant’ referred to by Fichter in 1926 has been identified as the fluoroxysulphate ion S04F-. The salts RbS04F and CsS04F have been prepared by the fluorination of Rb,S04 and Cs2S04 and the i.r.and Raman spectra agree well with those of the isoelectronic C104F and support the formulation O,SOF-. This has been confirmed by 19Fn.m.r.59a An X-ray study of the fluoroxysulphate anion in Rb’FOS0,-has shown that there is distorted tetrahedral co-ordination about the sulphur .59b More details of the i.r. spectrum of matrix-isolated SF, first reported last year have appeared60a and (He-I) photoelectron6” and microwave spectroscopic examinations6’‘ of the species have been made. Reactions between SCl, S2C12 SOCl, and S02C1 and Ph,CNLi have been used to provide new routes to (Ph,CN),S (Ph2CN)2S2 (Ph2CN),S02 and the novel compound PhzCNC(NSO)Ph2.61 Interest in the structures and bonding in HSSH H,SS and their halogen- substituted derivatives continues.Geometries which agree well with experimental data have been produced by SCF MO calculations and the as yet uncharacterized isomer H,SS is predicted to be as stable with respect to HSSH as F,SS is to FSSF.62“ Ab initio studies on the reactions of alkali-metal disulphides with alkali and alkaline-earth metals and their bonding indicate that univalent metals bind to one sulphur whereas the alkaline-earth melts may form additional bridged bonds between both sulphurs.62b In 1978 it was claimed that U.V. radiation of SzClz in an argon matrix produces SSCl,. Microwave results now indicate that only one sym- metric isomer of SZCl2 occurs in which the S-S bond length is shorter than the standard single bond length but not as short as that in S2F2.62C 55 M.C. R. Symons J.C.S. Dalton 1979 1469. 56 K. Fukuda C. Iwakura and H. Tamura Electrochim. Acta 1979,24,363. 57 R. Robbiani and J. L. Franklin J. Amer. Chem. SOC. 1979 101 3709. A. Goypiron J. de Villepin and A. Novak J. Chim. Phys. 1979 76 267. 59 (a)E. H. Appelman L. J. Basile and R. C. Thompson J. Amer. Chem. Soc. 1979,101 3384; (b)E. Gebert E. H. Appelman and A. H. Reis jun. Znorg. Chem. 1979,18 2465. 6o (a)A. Haas and H. Willner Spectrochim. Actu. 1978,34A 541; (6)D. M. de Leeuw R. Mooyman and C. A. de Lange Chem. Phys. 1978,34,287;(c)Y. Endo S. Saito E. Hirota andT. Chikaraishi J. Mol. Spectroscopy 1979,77 222. A. J. Banister J. A. Durtant J. S. Padley and K. Wade J. Inorg.Nuclear Chem. 1979,41 1415. 62 (a)A. Hinchliffe J. Mol. Structure 1979,55,127; (b)J. A. Pappas J. Amer. Chem. SOC., 1979,101,561; (c)C. J. Marsden R. D. Brown and P. D. Godfrey J.C.S. Chem. Comm. 1979 399. F. A. Hart A. G.Massey P. G.Harrison,and J. H. Holloway When gaseous mixtures of FSSF and SSF are subjected to a glow discharge it is the fluorodisulphane that is principally decomposed and SF,SF SF4 and sulphur are formed. 1.r. and n.m.r. data have been the means of characterizing SF3SF which has been shown to be thermally quite A new method for the preparation of [SCl,]'[AICI,]- by direct chlorination of sulphur in the presence of AlCl at 175 "C has been devised and the vibrational spectrum has been Chlorine-35 n.q.r. spectra of SCl,.MCl (M = Al Ga Au Nb Ta or Ti x = 4 or 6) have been The He-I photoelectron spectra of SF4 the related sulphuranes CF3SF3 (CF3),SF2 Me2NSF3 and (Me2N)2SF2 and the bis-sulphurane F,SCF,SF have been studied in order to obtain experimental ionization-energy data pertinent to a discussion of the bonding in molecules of this type.65" The fluorination of diphenyl sulphide with F2in CFCI at -78 "C has been shown to provide a convenient direct method for the preparation of the diphenylsulphur difluoride which itself is a fluorinating agent reacting with Ph3P Ph3As Ph3Sb Ph2Se Ph2Te PhCHO and Me3SiH to give Ph3PF2 Ph3AsF2 Ph3SbF2 Ph2SeF2 Ph2TeF2 PhCHF, and Me,SiF re~pectively.~'~ Reaction of SF4 with trimethylsilyl amines has produced new aminosulphur trifluorides and 'H and I9F n.m.r.studies have shown that the nitrogen in these compounds should be regarded as sp3rather than sp2 hybridized.66" An X-ray structural investigation of the molecule (Me2N)$3F2 which as well as being the first fluorosulphurane to be studied by X-ray methods is of special interest because of the presence of three proximate lone pairs has been carried out.66b Methylenesulphur tetrafluoride H2C=SF4 which was reported for the first time last year has been studied in more detail during 1979. The room-temperature i.r. and Raman spectra of CH2SF4 and CD2SF4 together with normal co-ordinate analysis of the fundamental vibrations have shown that the molecuIe has a strong C=S double bond and a rigid trigonal-bipyramidal arrangement about the s~lphur.~'~*~ A low-temperature X-ray structure determination indicates that the molecule is best thought of in terms of a covalent formulation in which a tetrahedron is linked with an octahedron (Figure 6).Chemical reaction with halogens results in the formation of SF,. Polar reagents cause addition to the C=S bond. Lewis acids interact with the carbon atom and bases attack the sulph~r.~" Figure 6 Structure of H2C=SF4 (Reproduced by permission from Angew. Chern. Internat Edn. 1979 18 944) " F. See1 and R. Stein J. Fluorine Chem. 1979,14 339. 64 (a)G.Mamantov R. Marassi,F. W. Poulsen S. E. Springer J. P. Wiaux R. Huglen and N. R. Smyre J. Znorg. Nuclear Chem. 1979,41 260; (b)Z. A. Fokina S. 1. Kuznetsov N. I. Timoshchenko and E. V. Bryukhova Zhur.fiz. Khim. 1979,53 146. " (a)A. H. Cowley M. Lattman and M. L. Walker J. Amer. Chem. Soc. 1979,101,4074; (b)I. Ruppert Chem. Ber. 1979,112,3023. 66 (a)C. Braun W. Dell H.-E. Sasse and M. L. Ziegler 2. anorg. Chem. 1979 450 139; (b) A. H. Cowley P. E. Riley J. S. Szobota and M. L. Walker J. Amer. Chem. SOC., 1979,101,5620. '' (a)S. Sunder H. H. Eysel G. Kleemann and K. Seppelt Inorg. Chem. 1979,18,3208;(b)H. Bock J. E. Boggs G. Kleeman D. Lentz H. Oberhammer E. M. Peters K. Seppelt A. Simon and B. Solouki Angew. Chem. Internat. Edn. 1979,18 944. The TypicalElements 101 A mixture of cis-and trans-isomers of Ph2SF4 in a ratio of about 1:2 has been prepared by fluorination of Ph2S. Hydrolysis of the mixture gives Ph2S02.68a Reaction of SF,C1 with keten gives CH3SF5 which is stable against HF elimination at room temperature.The analogous reaction with diketen gives compounds of the type SF5CH2X.68b Attempts to halogenate diorganyl sulphoxides directly have so far failed but it has now been shown that diarylsulphur(v1) oxide difluorides can be obtained by direct fluorination under mild conditions in the liquid phase. The 0x0-cation can also be obtained by hydrochlorination of the ammonolysis product (Scheme 4).69 R.8-I R2SO +F2 -;8 F =0 -[R2S(0)F]'PF6-RF Scheme 4 Rotational spectra of the molecules 32SF535C1 and 34SF535Cl 32SF537C1 have been and the mean vibrational amplitudes of SF,Br have been calculated.70b The spectroscopy of SF6 continues to attract enormous attention but these topics will not be covered here.A combined gas-chromatographic mass spectrometric and i.r. spectroscopic method has been developed to analyse the products of r.f. discharge on SF6 in glass apparatus. The compounds SF6 S02F2 SOF4 SOF2 SiF4 and F have been Progress with methods of preparation of four- and six-co-ordinate sulphur compounds stabilized by fluorine atoms and the perfluoroalkyl group including new routes to stable sulphuranes has been The synthesis and structure of the stable dichloro-alkoxysulphurane (Figure 7) have been reported and the CLI" CLl" ? 3 CLI' CLI' !9 ~,. a 1 Figure 7 Structure of dichlorosulphurane (Reproduced by permission from J. Amer. Chem. SOC. 1979,101 3595) 68 (a)I. Ruppert J. Fluorine Chem. 1979,14,81; (6)G.Kleemann and K.Seppelt Chem. Ber. 1979,79 1140. 69 I. Ruppert Angew. Chem. Znternat. Edn. 1979 18 880. 70 (a)J. Bellet R. Jurek and J. Chanussot J. Mol. Spectroscopy 1979,78 16; (bj E. J. Baran Z. Chem. 1979 19 190. " G. Bruno P. Capezzuto and F. Cramarossa J. Fluorine Chem. 1979,14 115. '* (a)T. Kitazume and N. Ishikawa Yuki GoseiKagaku Kyokaishi 1979,37,413; (b)L. D. Martin E. F. Perozzi and J. C. Martin J. Amer. Chem. SOC., 1979,101,3595;(c)E. F. Perozzi and J. C. Martin ibid. p. 1155. F.A. Hart A. G.Massey P.G.Harrison and J. H.Holloway conformation of the difluoro analogue has been found to have an apical alkoxy ligand and an equatorial fluorine. The crystalline chloro-derivative however exists as a tetramer with bridging chlorine ligands and an octahedral arrangement of ligands around The synthesis and reactions of trialkoxysulphurane were reported several years ago but two structures (21) and (22) can be written which satisfy electronegativity rules and the stricture against diapical five-membered rings.An X-ray has now shown that (21) is correct which confirms earlier n.m.r. work. ORf Few sulphenic acids have been isolated because they have high reactivity as either nucleophiles or electrophiles. Sulphenato-complexes on the other hand can be prepared and are stable. Complexes such as those where S-bonded sulphenic acids are co-ordinated to Co"' provide a means of investigating the chemistry of sulphenic acids. The syntheses structures and chemical reactivities of several bis(ethy1- enediamine)cobalt(III) complexes have been investigated and the reactivity of the co-ordinated acids has been probed by an investigation of the kinetics and mechanism of the oxidation of [(en)2Co{S(0)CH2CH2NH2}]2+ with H202.73 The 'metallic' non-metals the tetrathiafulvalenes continue to be of interest.Recommended routes to TTF (TTF)3(BF4)2 and other salts have been published74" and studies of the optical properties of the radical cation in its mixed-valence and single-valence halide salts have been made.74b The crystal structure disel- enadithiafulvalene has been determined.74c Metal-tetrathiolene chemistry has been the subject of recent research and this has resulted in the observation of the first di-(pS)-bridge between two metal atoms in the compound [(Ph3P)2(C8)2Br21r2(C10H4S4)] (23).The molecule appears to be a rare example of electronic effect prevailing over steric constraints. Instead of adopting the sterically more favourable [(Ph3P)-(CO)BrIrS2CloH4S21rBr(CO)(PPh3)] structure of the related diplatinum tetra-thiolene relatives it adopts an electronically more favourable six-co-ordinate 18-electron configuration about the Ir11.756 The resonance Raman and the i.r. and Raman spectra of tetrathiatetracene have been Tentative 73 I. K. Adzamli K. Libson J. D. Lydon R. C. Elder and E. Deutsch Inorg. Chem. 1979,18 303. 74 (a)F. Wud! and M. L. Kaplan Inorg. Synth. 1979,19,27;(b)J. B. Torrance B. A. Scott B. Welber F. B. Kaufnian and P. E. Seiden Phys. Rev. (B),1979,19,730;(c)V.K. Bel'skii and D. Voet J. Cryst.Mol. Structure 1979 8 9. " (a)B.-K. Teo 'Inorganic Compounds with Unusual Properties' A.C.S. Adv. Chem. Ser. ed. R. B. King No. 173,1979,p. 364; (b)B.-K. Teo and P. A. Snyder-Robinson J.C.S. Chem. Comm. 1979,255; (c) L. M. Kachapina M. G.Kaplunov E. B. Yagubskii and Yu. G. Borod'ko Chem. Phys. Letters 1978,58 394; (d)L. M. Kachapina M. G.Kaplunov A. I. Kotov 0.N. Eremenko E. B. Yagubskii and Yu. G. Borod'ko Zhur. priklud. Spektroskopii 1979,30,84. The Typical Elements s-s Rr /% \ Phi Ph3P-Ir -co LO / (23) assignments of some of the i.r. and Raman bands have been made and differences between the spectra of the neutral and cationic species noted? Selenium and Tellurium.-The chemical and physical properties occurrence analyses and toxicities of selenium and selenium compounds have been reviewed.76 Selenium and tellurium homolytic and heterolytic ring and chain systems continue to excite activity.Lattice constants for tellurium powder and evaporated film have been and variation of lattice parameters with pressure for trigonal selenium and tellurium has been Raman spectrosqopy has been used for the identification of sulphur selenium and tellurium phases in -10 cavity zeolites. In addition to known stable and unstable phases evidence for Te8rings is reported to have been Raman studies on Se,S8- have shown that the mixed crystals contain entities with homonuclear Se-Se bonds which are not Se8.25a Following measurements of the viscosity density and surface tension of liquid tellurium last year,79asimilar measurements on Se,Tel- melts have shown that for the tellurium-rich alloys there is a non-linear relationship with respect to tempera-ture which is related to co-ordination number.79b The electronic structure and localized molecular orbitals in Se82' have been studied the~retically.~~' Viscosity determinationson SeS2' and Se4*' in about 100°/~ H2S04indicate the presence of SeS2+and Se42+solvates containing three and six &SO4 molecules respectively." Preliminary data on the Te64+structure appeared in 1976 and now full details of the preparation spectroscopic properties and X-ray crystal structures of Te6(AsF,),.2AsF and T~,(AsF~)~.~SO~ have been reported.Electronic spectroscopic studies are also included which show that the species previously identified as 'Te,"" in highly acid media is in fact Te64+cation.81 76 L.M. Dalderup and H. J. Klein Obbink Voeding 1979,40 260. 77 (a)Z. Muro Suzuka Kogyo Kofo Semmon Gakko Kiyo 1979,12,101;(6)S. Minomura K. Aoki N. Koshizuka andT. Tsushima High-pressure Sci. Technol.,AIRAPT Conf. 6th. 1977,(Pub. 1979),ed. K D.Timmerhaus and M. S. Barber Plenum New York N.Y. Vol. 1 p. 435. 78 V. N. Bogomolov A. E. Zadorozhnii V. P. Petranovskii A. V. Fokin and S. V. Kholodkevich Pis'ma Zhur. eksp. Teor. Fiz.,1979,29,411. 79 (a)R. Barrue J. F. Rialland and J. C. Perron Rev. Phys. Appl. 1978,13,421;(6)J. F. Railland J. C. Perron and J. Robert Phys. Letters (A),1979,72,467. V. S.Epifanov V.G. Moshkova and L. V. Konyakhina Zhur. priklad. Khim. 1978,51,2668. 81 R. C.Burns R. J. Gillespie W.-C. Luk and D. R. Slim Inorg. Chem. 1979 18 3086. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Several heterolytic ring systems have been newly observed and novel uses for known systems have been found. Notable amongst the new species is the novel red dianion [BllH9Se3]2- (Figure 8) in which the Se3 chain is bonded to two adjacent Figure 8 Structure of the [B H9Se3lz-ion (Reproduced by permission from Inorg. Chem. 1979 18,755) boron atoms of the closo cage.82o Although organic compounds containing Se-B bonds have been known for some years their potential for functional group inter- conversion has been little recognized. A good example of such utility is the newly discovered fact that (24) and B(SePh)3 and B(SeMe) are very useful for the rapid Se-Se I\ BuB ,BBu Se (24) deoxygenation of sulphoxides at or below room temperature.826 Reaction of MezSnClZ with NaHTe in aqueous solution gives the Sn3Te3 ring compound (MezSnTe), which can be easily separated as yellow needles.This is an improved route to the Sn,Te3 ring. The earlier dimethylstannane-tellurium reaction gave mixtures with the Sn3Tez ring. The crystal structure of (MezSnTe) (Figure 9) has been dete~mined.~~ The (q2-Sez) complex [Os(q2-Sez)(CO)z(PPh3)z] has been characterized by X-ray single-crystal methods and the Sez ligand has been found to be ‘sideways’ bonded to the osmium. The reactivity of the (v2-Sez) and the (v2-Sz) ligands has been investigated and in complete contrast to the (~~-0~) analogues which are oxidizing in character they have been found to have reducing proper tie^.^^ The first example 82 (a)G.D. Friesen J. L. Little J. C. Huffman and L. J. Todd Znorg. Chem. 1979 18 755; (b)D. L. J. Clive and S. M. Menchen J.C.S. Chem. Comm. 1979,168. 83 A. Blecher and M. Drager Angew. Chem. Internat. Edn. 1979,18,677. 84 D. H. Farrar K. R. Grundy N. C. Payne W. R. Roper and A. Walker J. Amer. Chem. SOC.,1979,101 6577. The Typical Elements 105 Figure 9 Structure of (Mn2SnTe)3 (Reproduced by permission from Angew. Chem. Internat. Edn. 1979 18,677) of a diselenide bridging a metal atom has appeared with the reporting of the synthesis and crystal structure determination of [(PtMe3Br)2MeSeSeMe],85 and the Se22- ion has been observed for the first time in the structure of [ASP~~)~[W~C~,S~~].~~ The first microwave investigation of the molecular rotational spectrum of hy- drogen telluride has been rep~rted.~' Argon fluoride laser-induced photolysis of carbonyl selenide has been A new simple in situ preparation of carbonyl selenide from selenolcarbamate and sulphuric acidg9" has provided an opportunity to investigate its reactions with amines and amino-alcohols with which it behaves as a carbonylating agent.89b New' dialkyl tellurides Te[(CH,),SiMe,] (n = 1 or 3) have been prepared by alkylation of Na2Te with the corresponding alkyl chlorides.Co-ordination complexes of the new ligands with PdC1 and Pd(SCN) have also been prepared.A single-crystal structure of [Pd(SCN),(Te(CH2CH2CH2SiMe3)},] has revealed pyra- midal co-ordination about the tellurium with a stereochemically active lone pair of electrons at the fourth corner of the tetrahedron." The [TeMeJ' cation in [TeMe3]'[BPh4]-has been shown to be pyramidal and surrounded by a trigonal- bipyramidal arrangement of [BPh4]- ions.91 The microwave rotational spectrum of MeSeCN containing various Se isotopes has been studied in detail.92 The transient absorption produced by pulse radiolysis of *' E. W. Abel A. R. Khan K. Kite K. G. Orrell V. Sik T. S. Cameron and R. Cordes J.C.S. Chem. Comm. 1979 713. 86 M. G. B. Drew G. W. A. Fowles E. M. Page and D. A. Rice J. Amer. Chem. SOC. 1979,101,5827." A. V. Burenin A. F. Krupnov S. V. Mart'yanov A. A. Mel'nikov and L. 1. Nikolayev J. Mol. Spectroscopy 1979,75 333. 88 (a)W. K. Bischel G. Black R. T. Hawkins D. J. Kligler and C K. Rhodes J. Chem. Phys. 1979,70 5589; (b)W. K. Bischel J. Bokor J. Dallarosa and C. K. Rhodes ibid. p. 5593. 89 (a)K. Kondo S. Yokoyama N. Miyoshi S. Murai and N. Sonoda Angew. Chem. Internat. Edn. 1979 18,691; (6)K. Kondo S. Yokoyama N. Miyoshi S. Murai and N. Sonoda ibid. p. 692. 9" H. J. Gysling H. R. Luss and D. L. Smith Znorg. Chem. 1979 18 2696. 91 R. F. Ziolo and J. M. Troup Znorg. Chem. 1979 18 2271. 92 T. Sakaizumi Y. Kohri 0.Ohashi and I. Yamaguchi Bull. Chem. SOC.Japan 1978,51,3411. 106 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway SeCN- has been shown to be due to the radical (SeCN)2- and the reactivity of this radical with amino acids has been studied.93 The X-ray crystal structure of the bis(triphenylphosphorany1idene)ammonium salt of tellurocyanate has shown that the TeCN- ion is linear.94 The structures of Se(SCN) and the isomorphous Se(SeCN)2 have also been examined by X-ray means.The tendency to square- planar co-ordination about the selenium observed previously in the sulphur deriva- tive has been c~nfirmed.~~ The structure of tris(se1enourea) sulphate selenourea solvate dihydrate (su),SO4.su.2H2O has been studied because it was thought that the compound might contain a linear four-atom sequence of seleniums. However the structural investigation has shown that it contains the familiar three-selenium system with the fourth selenourea molecule as a s01vate.~~ The vibrational and photoelectron spectra of 2Te02.HN03 2Te02.HC104 and 2Te02.S03 indicate that the structures contain covalent Te-0 bridges whereas the acid groups are ionic with weakly distorted symmetrie~.~~ Reaction of Se03 with AsF results in the formation of oligoselenic acids both in liquid SO and in the absence of an inert s01vent.~' Conductance measurements on a variety of selenoxides selenones and selenides in chlorosulphuric acid have shown that alkyl selenoxides such as Me2Se0 and selenones such as Me,Se02 or Et2Se02 are completely ionized as bases.The phenyl derivatives and nitro-derivatives on the other hand are only weakly basic. Selenones are stronger bases than the corresponding ~ulphones.~~ E.s.r.studies on irradiated single crystals of triglycine selenate have shown that Se-0 bond scission is not uniform and two linds of Se02- radicals are produced.100 Flash photolysis of the selenatelo'a and tellurate(1v) anionslolb in aqueous solution gives rise to the transient species Se03- and TeO,- in addition to 02-.The X-ray structures of both Na2Te03.5H20102a and the monoclinic and orthorhombic forms of BaTe0,1°2' show that the structures contain pyramidal Te032- anions. The phase transition and high-temperature phase structures of ferroelectric SrTe03 have been investigated by X-ray and polarized optical New 77Se Fourier-trans- form n.m.r. measurements on solutions of H2Se0, Na2Se03 NaHSeO, and Na2Se04 in water have been made.Io4 Pulse radiolysis studies on aqueous solutions of Se042- show that Se04- is produced by the reaction shown in equation (8).In flash photolysis it is produced as OH +Se042-+ OH-+Se04-(8) 93 R. Badiello and M. Tamba Radiochem. Radioanalyt. Letters 1979 37 165. " A. S. Foust J.C.S. Chem. Comm. 1979,414. 95 S. Hauge Acta Chem. Scand. 1979 A33,313. 9d S. Hauge Acta Chem. Scand. 1979 A33 317. 97 E. Lehmann and E. Diemann Z. anorg. Chem. 1979,449 83. 98 J. Touzin L. Meznik and L. Mitacek Coll. Czech. Chem. Comm. 1979,44 1530. 99 R. C. Paul D. Konwer D. S. Dhillon and J. K. Puri J. Inorg. Nuclear Chem. 1979 41 55. loo Y. Kotake and K. Kuwata Bull. Chem. SOC. Japan 1979,52 321. lo' (a) M. S. Subhani and T. Kausar Rev.Roumaine Chim. 1978 23 1627; (6)M. S. Subhani and T. Kausar ibid. p. 1341. I"* (a)E. Philippot M. Maurin and J. Moret Acta Cryst. 1979 B35,1337; (b)M. Kocak C. Platte and M. Tromel 2.anorg. Chem. 1979 453,93. I. H. Ismailzade A. Yu. Kudzin and L. Ya. Sadovskaya Phys. Status Solidi 1979 A52 K105. '04 W. Koch 0.Lutz and A. Nolle 2.Naturforsch. 1978 33a 1025. The Typical Elements in equation (9).lo5Considerable attention has been paid to the commensurate and incommensurate phases in potassium selenate K2Se04,'06a-s and ferroelectric properties of ammonium hydrogen selenate NH4HSe0, have been observed by measurements of permittivity in the crystals.'06d Se042-.H20 -+Se04-+e& (9) Crystal structures of a large number of selenate(v1) and tellurate(V1) molecules have been determined.These include and SeO,*- species the products of the NH3-Te03-H20 and the mixed oxotellurates BaTe206107d and NH4[Te,0s(OH)].'07' The latter two both contain TeV'06 octa- hedra and TeIVO5 pyramidal groups. In the barium salt the Te06 and Te0 groups are connected by common corners to form Te206 whereas in the ammonium salt the Te06 octahedral chains and TeO pyramids are linked through the NH4+ cations.'07e The structures of Te(OH)6.2(NH4)2HP04 Te(OH)6.Na2HP04.H20,'07f(NH4),Te02(0H) contain octahedrally co-and ordinated tellurium anions1o7R whereas that of a-Te2Mo07 contains two chemically different Te atoms in the structure although both have pseudo-octahedral environment^."^^ Reaction of heated selenium with very much diluted elemental fluorine gives a mixture of lower selenium fluorides.Amongst these the new species SeF and FSeSeF have been unambiguously identified by i.r. examination of the 76'82Se- substituted compounds. During U.V. photolysis it has been found that FSeSeF is partially converted into Se=SeF2.108 He-I photoelectron spectroscopy of mixtures of elemental selenium with halogen atoms has yielded the first ionization energy of SeF and valence ionization energies of SeC12 and SeBr2.109 Phase relationships in the Se-Br system have been studied in detail and two intermediate phases with congruent melting behaviour a-SeBr and a-SeBr, have been obtained. The p-forms of these molecules are metastable with respect to the phase diagram and are converted into the a-modifications b.y annealing.Single crystals of trigonal a-SeBr and monoclinic P-SeBr4 both have tetrameric cubane-like structures (e.g. Figure 10) but have different spatial arrangements.'" Chlorine-35 n.q.r. spectra of SeCl3.MCI4 (M = Au Al or Ga) measured at 77 and 296 K are consistent with the complexes having ionic Solid-state Raman spectra of SeBr,.AlX (X=C1 or Br) clearly indicate the presence of pyramidal (C3") [SeBr,]' ions in these adducts but a Raman spectrum of the product from the reaction of SeClBr and SbCl is more complex. Although [SeBr3]' is M. S. Subhani and M. Khalid Rev. Roumaine Chim. 1978,23 11 17. (a) K. Inoue K. Suzuki A. Sawada Y. Ishibashi and Y. Takagi J. Phys. SOC.Japan 1979,46,608; (6) A. K.Jain Solid State Comm. 1979,31,237; (c)P. A. Fleury S. Chiang and K. B. Lyons ibid.,p. 279 (d)Z. Czapla T. Lis and L. Sobczyk Phys. Status Solidi 1979 A51 609. '" (a)J. Valkonen Ann. Acad. Sci. Fennicae Ser. A2,1979,188,36 (Chem.Abs. 1979,91,66 671); (6)M. A. Nabar and S. V. Paralkar J. Appl. Cryst. 1979,12,245; (c) J. Moret M. Maurin and E. Philippot Rev. Chim. minkrale 1979,14 39; (d)M. Kocak C. Platte and M. Troemel Acta Cryst. 1979 B35 1439; (e) E. Philippot L. Benmiloud M. Maurin and J. Moret ibid. p. 1986; (fl A. Durif M. T. Averbuch-Pouchot and J. C. Guitel ibid. p. 1444; (g) G. B. Johansson 0.Lindqvist and J. Moret ibid. p. 1684; (h)J. C. J. Bart and N. Giordano Gazzetta 1979 109 73. In*A. Haas and H. Willner Z. anorg. Chem. 1979,454 17. '09 D.M. De Leeuw R. Mooyman and C. A. De Lange Chem. Phys. 1979,38 21. P. Born R. Kniep and D. Mootz Z. anorg. Chem. 1979 451 12. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Br Br Br Figure 10 Structure of SeBr4 (Reproduced by permission from 2.anorg. Chem. 1979 451 12) present the spectrum is not consistent with the [SeBr3]+[SbC16]- structure."' The structure of trans-bis(benzothiazolethione-S)tetrachlorotellurium(Iv)-dioxan(1/2) (Figure 11)has been determined by X-ray methods and can be interpreted in terms of an addition compound of the thione-form of mercaptobenzothiazole with TeC14.I * Figure 11 Structure of trans-bis(benzothiazolethiane-S)tetrachlorotellurium(w)-dioxan (Reproduced by permission from Crystal Structure Comm.1979 8 221) Selenium tetrafluoride has been prepared by direct fluorination at low tempera- ture and pressure and the temperature and heat of fusion have been determined. Analysis by chemical microsublimation and mass spectrometric methods has been de~cribed.''~~ The standard heat of formation of SeF4 has been determined by alkaline hydrolysis. From measurements of the temperature dependence of the I" A. Finch P. N. Gales and D. R. Netherton Inorg. Chim. Acta 1979 32 L91. 'I2 K. Von Deuten W. Schnabel and G. Klar Cryst. Structure Comm. 1979 8 221. 'I3 (a)J. Carre P. Claudy J. M. Letoffe M. Kollrnannsberger and J. Bousquet J. Fluorine Chem. 1979,14 139; (b) J. Carre P. Germain M. Kollmannsberger G. Perachon and J. Thourey ibid. p. 367; (c) J. Haag U.Von Alpen E. Gmelin and A. Rabenau 2.Naturforsch. 1979,34a 969; (d)V. S. Borzhirn V. I. Levchenko A. A. Mogil'nitskii and L. I. Prokopovich Ukrain. Khim. Zhur. 1979 45 789. The TypicalElements e.m.f.s of solid-state galvanic cells the standard entropies and heats of formation of Te3CI2 TeCl, Te2Br TeBr, a-TeI and TeI have been calculated. The free energies of reaction for the Te-TeX systems were also determined."3c The free energy of formation of Te14 has been obtained from measurement of the vapour pressure of iodine over TeI and from the potential of a solid-phase cell.''3d Raman spectra of [SeCl,]- and [SeCl6I2- have been examined in the solid state and in solution in MeCN."," Alkali-metal NH4+ CSH5NH+ and Bu4N' salts of the [TeFJ ion have also been examined by vibrational spectroscopic methods and assigned C symmetry.' 14' Low-temperature vibrational spectra have been used to examine phase transitions in K2TeC16 and K2TeBr6.N.m.r. data for Bu4N+TeF5- have been reported but no evidence for [TeF6I2- could be The single- crystal X-ray structure of [Me4NI2[TeBr6] has been investigated and the compound has been found to crystallize in the cubic Fd3c space group. Other tetramethylam- monium hexametallates have been assigned the Fm3m space group and it has now been suggested that this may only be a first appro~imation."~~ Enthalpies of complexation for the reactions (10) have been measured by solution calorimetry. 2MX(,) + + M2SeX6(,) (M =K or Rb X = C1 or Br) (10) Lattice energies and standard heats of formation for the salts have also been reported."' A new synthesis of TeBrF from bromine fluorine and TeF4 has been reported and the vibrational spectrum has been obtained and The trimeric anion [Te3Cl13]- has been obtained in benzene solution as a degrada- tion product of cubane-like Te4Cl16 and isolated by crystallization as a salt using the large Ph3C+ cation.The trimeric anion has approximately C, symmetry and consists of three edge-sharing octahedra with a central triply bridging chlorine.' l7 Fourier-transform n.m.r. techniques continue to be used to advantage in the study of Se and Te compounds. Relaxation considerations are of significance when dealing with molecules of biological importance. Dialkyl selenides dialkyl and diary1 diselenides selenols selenonium compounds and seleno oxyacids are all associated with biological systems and relaxation times for these molecules have been measured under a variety of conditions.It is clear that spin-rotation and chemical-shift anisotropy mechanisms are the most important means of spin-lattice relaxation for the 77Se nucleus and the dipole-dipole mechanism is totally absent.l'* Reactions involving organo-selenium and -tellurium have received much atten- tion this year. Oxidative addition of dihalogens and alkyl halides to dialkyl- tellurium(I1) has been known for a long time and more recently the oxidation of R2Te to R2TeXY by inter-halogens cyanogen halides and thiocyanogen has been observed. It now appears that diaryltellurium(I1) can insert between N-halogen bond^.'''^ Diorganylseleniurn and tellurium difluorides R'R2ZF2 (R' = R2= Ph (a)P.Lattaie and J. Milne Inorg. Chem. 1979 18 632; (b)R. J. Morris and K. C. Moss J. Fluorine Chem. 1979,13,551;(c)S. L. Chodos and R. W. Berg J. Chem. Phys. 1979,70,4864;(d)R. W. Berg and K. Nielsen Acta Chem. Scand. 1979 A33 157. '" H. D. B. Jenkins R. Makhija and A. D. Westland J. Chem. Res. (S) 1979 68. 'I6 L. Lawlor and J. Passmore Inorg. Chem. 1979,18 2921. '" B. Krebs and V. Paulat Z. Naturforsch. 1979 34b 900. J. D. Odom W. H. Dawson and P. D. Ellis J. Amer. Chem. SOC. 1979 101 5815. (a) T. N. Srivastava R. C. Srivastava and M. Singh Inorg. Chim. Acta 1979,33 L99; (b)V. Kumar P. H. Bird and B. C. Pant Synth. React. Inorg. Metal-Org.Chem. 1979,9,203; (c)T.N. Srivastava R. C. Srivastava and K. Kapoor J. Inorg. Nuclear Chem. 1979,41,413;(d)W.Schnabel K. Von Deuten and G. Klar Chem.-Ztg. 1979 103 231. 110 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway 2=Se or Te; R' = R2= Me Z = Te; R' =Me R2=Ph Z = Se or Te) have been prepared by direct fluorination of R'R'Z with elemental fluorine at -78°C.6Sb Organotellurium halides are often produced by the cleavage of carbon-metal bonds with TeC1,. New examples include the use of organoplumbanes and diplumbanes' 19' and aryl-indium -thallium and -germanium corn pound^.^'^^ Reaction of TeC1 with sodium diethyldithiocarbamate trihydrate in dioxan gives the much more unusual product Te(S2CNEt2)3Cl.dioxan.1'9d The triphenylselenonium chloride hydrate Ph3SeCl.H20 which was previously reported to be anhydrous has been synthesized and the structure shown to consist of triphenylselenonium cations chloride ions and water molecules linked by a secondary binding scheme involving shorter than van der Waals Se-Cl and Se-0 distances.The salt is monomeric with five-co-ordinate Se.I2' X-Ray irradiation of single crystals of Ph3SeC1 has produced the diphenyl- selenonium chloride radical trapped in the crystal matrix.121 The chemical behaviour and spectra of dialkyltellurium tetraiodides have sugges- ted for several years that the structure is built up of Me2Te12 and I2 molecules and does not contain Te"'. This has now been confirmed by a single-crystal X-ray determination (Figure 12).One iodine of the Me2Te12 unit is connected with the Iz molecules and is part of two crystallographically independent but similar I4 groups. 12' Figure 12 Structure and labelling of Me2Te14 (Reproduced by permission from Inorg. Chem. 1979,18 31 1) The synthesis analysis enthalpy of fusion enthalpy of vaporization,"3" and enthalpy of f~rmation"~' of SeOF2 have been obtained. Because of differing interpretations as to what species occur in aqueous hydrochloric acid solutions of Se02 an investigation of such solutions by Raman methods has been carried out. These show that 'dichloroselenious acid' formed from a 2 :1 HC1-SeO2 mixture (1:1 SeOCl2-HZ0) is a hydrate of seleninyl chloride. The principal Se'" species present in solutions of Se02 in concentrated HCl is also seleninyl chloride and not chloroselenate(1v) ion.The equilibrium constant for the reaction (1 1) has been H2Se03+2HC1 SeOCI2+2H20 (11) lZo R.V. Mitcham B. Lee K.B. Mertes and R.F. Ziolo Inorg. Chem. 1979 18 3498. M. Geoffroy J. Chem. Phys. 1979 70 1497. H. Pritzkow Inorg. Chem. 1979 18 31 1. The Typical Elements determined and at higher concentrations of HCI (15-18 M) penta-chloroselenate(1v) ion is produced ( Raman spectra of SeOBr2 solid melt SeOC1 +3HC1 $ H30++SeC15-(12) and solution in CCl have been observed for the first time. The molecules are associated in the molten state but are monomeric pyramidal molecules in solu- tion.'*," Solid and MeCN solution spectra of [SeO,Cl]- and [SeOC13]- are consis- tent with pyramidal and trigonal-bipyramidal (with two axial chlorines) structures re~pectively.'~~" The Raman spectrum of [SeOCl4I2- is consistent with it having a square-pyramidal structure with an axial oxygen atom trans to the lone pair of electrons.The ion was prepared by reaction of SeOCl with MCl [M = Ph4As Et4N or bipyH2 (bipyridinium dichloride)]. 124b The recent chemistry of the HOSeF and HOTeF molecules has been reviewed.125 Thermal decomposition of vapour-phase Se202F8 and Te2O2Fg which were first prepared in 1974 by the vacuum pyrolysis of Na'SeOF,-and Li'TeOF,- have been studied by mass spectrometry electric deflection and flight-time analysis on a molecular beam generated directly from the decomposition products. In both cases the principal products are the tetrafluoride molecular oxygen and the oxide difluoride.'26" The molecular structures of the same two compounds have been determined in the gas phase by electron diffraction and the dimeric structures have been confirmed.The configurations about the chalcogen atoms are considerably distorted from Reaction of CuSe03 with TeCl has produced a new oxide chloride of composition Cu,Se,O,Cl which from an X-ray crystallographic study has been shown to consist of a three-dimensional network containing Se'" with its stereochemically active lone pair at the apex of a tetrahedron formed with three oxygen The crystal structure of diselenadithiafulvalene C6H4S2Se2, has been determined by direct Tetraselenotetracene has been the source of much Russian work.It has been synthesized from 5,6,11,12-tetrachlorotetraceneand sodium diselenide,'28" and a number of salts have been prepared by oxidation of tetraselenotetracene (TSeT) e.g. (TSeT),Br (TSeT)2Cl (TSeT)I,, (TSeT)(SCN)o.5 (TSeT)(SeCN),., (TSeT),[Pt(CN)J2 and (TSeT)7(IrC16)2.'28b Resonance Raman spectra of TSeT7," and i.r. and Raman spectra of TSeT and its cation have been studied"" and structures of (TSeT)'Cl- and (TSeT)'(SCN)- have been determined.129 J. Milne and P. Lahaie Inorg. Chem. 1979 18 3180. (a)W. Brockner and A. F. Demiray Monatsh. Chem. 1979,110,525;(b)J. Milne Inorg. Chem. 1979, is,2924. lZ5 K. Seppelt Accounts Chem. Res. 1979 12 211. (a) M. J. Vasile F. A. Stevie and K. Seppelt J. Fluorine Chem. 1979,13,487;(b)H. Oberharnmer and K.Seppelt Inorg. Chem. 1979 18 2226. '" J. Galy J. J. Bonnet and S. Anderson Acta Chem. Scand. 1979 A33 383. lZ8 (a) K. Balodis A. Livdane R. Medne and 0. Neilands Zhur. org. Khim. 1979 15 391; (6) 0. N. Eremenko S. P. Zolotukhin A. I. Kotov M. L. Khidekel and E. B. Yagudskii Izoest. Akad. Nauk S.S.S.R. Ser. khim. 1979,7 1507. R. P. Shibaeva and V. F. Kaminskii Kristallografiya 1978,23,1183;R. P. Shibaeva V. F. Kaminskii A. Kotov E. B. Yagubskii and M. L. Khidekel ibid. 24 271. 112 E A. Hart A.G.Massey P. G.Harrison and J. H. Holloway 3 GroupVII Russian books on n.m.r. in inorganic and on fluorine calorimetry1306 have appeared and fluoride crystal structures have been re~iewed.'~' Chemical formulae do not reveal the co-ordination behaviour of all atoms and a new attempt has been made to interpret chemical formulae in the context of solid-state chemistry using a modified 'Niggli' approach to express this in terms of 'motifs of co-ordination'.13' Reviews on halogen bomb calorimetry with special reference to fluorine flame ~alorirnefry,'~~~ and halogen recombination-dissociation reactions134 have also been published this year. A new field of investigation has been provided by the discovery of new highly excited electronic states of atoms. Excited iodine atoms 1(5~~6s~P~,~) have been produced by U.V. multiphoton excitation of CD31 with a noble-gas halogen exciplex laser and the chemistry of this and related species is now being Last year new C1' derivatives including the highly electrophilic CF3SO20C1 were prepared for the first time.Now the syntheses of CF3CO2C1 C2F5CO2C1 C3F7CO2C1 HCF2COZCl and ClCF2C02C1 by reaction of the corresponding acids or their sodium salts with CIF at low temperatures have been described. Evidence for CF2(CF2C02C1)2 has also been found. The new compounds have been charac- terized by n.m.r. and vibrational spectroscopic methods as well as by observation of their decomposition product^.'^^ Halogeno homopolyatomic cations have been of interest during the past decade. The crystal structure of 15SbF6 made by the oxidation of iodine with SbF5 has shown that the cation is a bent Is+ chain and that three Is+ units are loosely joined to form what may be regarded as an 1153+ The observed crystal structure of chlorine at low temperature has been used to derive optimized potential-energy parameters.These show that an intermolecular partial bond is necessary for a good fit.13* Investigation of reactions between halogens and phosphorus(II1) halides in strongly acidic solvents have been studied by 31 P n.m.r. spectroscopy and reactions of PX3with Xz(X = C1 or Br) have been shown to give mixtures of [PBr,-,Cl,]' ions together with solvolysed Although reactions of halogens with polynuclear metal carbonyls have been extensively used to prepare mononuclear halogeno-carbonyls in high yield little is known of the mechanisms involved. Recent studies of the kinetics of reactions of bromine with axially substituted complexes [Mz(CO)lo-,L,] (M2 = Mnz MnRe or Rez n = 1or 2 L = phosphorus donor ligand) indicate fast reactions with initial one-electrophilic (a)S.P. Gabuda Yu. V. Gagarinskii and S. A. Polishchuk N.M.R. in Inorganic Fluorides Structure and Chemical Bonding' Atomizdat Moscow 1978; (6)V. Ya. Leonidov and V. A. Medvedev 'Fluorine Calorimetry' Nauka Moscow 1978. 13' G. B.Bokii N. L. Smirnova I. A. Rozdin and V. S. Sergienko Itogi Nauki Tekh Kristallokhim. 1979 13,s. 13' R. Hoppe J. Solid State Chem. 1979 27 99. 133 (a)G.K. Johnson V. Ya. Leonidov and W. N. Hubbard Exp. Chem. Thermodynamics 1979,1,12/1; (b) G. T. Armstrong and R. C. King ibid. p. 15/1. R. K. Boyd and G. Burns J. Phys. Chem. 1979,83,88. 134 13' C. Fotakis M. Martin and R. J. Donovan J.C.S. Chem. Comm.1979 813. 136 I. Tari and D. D. DesMarteau Inorg. Chem. 1979 18 3205. 13' J. Passmore P. Taylor T. Whidden and P. S. White Canad. J. Chem. 1979,57,968. 13' L.-Y. Hsu and D. E. Williams Inorg. Chem. 1979,18 79. 139 (a) K. B. Dillon M. P. Nisbet and T. C. Waddington J.C.S. Dalton 1979 1591; (b)G. Kramer J. Patterson and A. Pot ibid. p. 1165. The Typical Elements 113 attachment of one or more Br molecules at the oxygens of the carbonyl ligand~.'~~~ Studies of the effects of pressure on iodine complexes with Et20 Et2S and Et,Se have been studied up to 300 bar at 25 0C.140 Halogen anions and polyatomic anions continue to be of interest. It has been shown that a mixture of tetra-n-butylammonium chloride and potassium fluoride dihydrate in acetonitrile is a convenient source of active fluoride ion and can replace tetra-alkylammonium fluoride or potassium fluoride crown ether combinations which are difficult to obtain in an anydrous state or are expen~ive.'~' Novel Br- salts have been found to result from the reaction of S4N4 with Br in CS236c and the structure of S4N3+Br3- one of the few stable compounds containing the tribromide ion has shown that the degree of asymmetry of the near-linear Br3- ion is inter- mediate between that found in PBr and that in [Me3NH+]2Br-Br3-.36E The heat of formation of C13- has been estimated to be -300.1 kJ mol-' from studies of negative ion-molecule reactions in sulphuryl halides5 The halogen that exhibits the strongest tendency to catenate is iodine.A new salt of the Ig2- ion [(CH2)6N4Me]21g has been shown by X-ray single-crystallographic studies to contain an outstretched form of Is2-rather than the familiar 2-form found in the caesium Theoretical studies on FH have been carried Various aspects of the reactions of fluorine atoms with H2,144a76 and other small molecules such as CH3,144C 02,144d+e and HBr144f continue to warrant study.Rate constants for the reactions of hydrogen atoms with Ft Clz FCl and IC1145a and 1 and HI'456 have been measured and discussed. The effect of energy branching on the photoinitiated explosion of hydrogen-fluorine mixtures has been investigated. 14' The interaction of rotationally and vibrationally excited hydrogen halides continues to attract considerable attention. However this is reviewed elsewhere in this Annual Report and will not be covered here.Rate constants of the reactions of the hydrogen halides with NO have been calculated by means of the transition-state theory combined with the bond energy-bond order method and have been compared with experimental data.14' Information on hydrogen-bonding continues to come from studies of HF (HF), and liquid HF. Anharmonicity is a fundamental quantity for the understanding of H-bonding. Experimental determination of this quantity entails the measurement of overtones and combination bands preferably in the gas phase so as to be free of solvent effects. Observation of the i.r. spectra of the volatile complexes of HF with Me20 Et20 and acetone has made measurement of the first overtones of H-F and D-F stretching vibrations possible.'48 Theoretical calculations on the dissociation I4O S.Sawarnura Y.Taniguchi and K. Suzuki Bull. Chem. SOC. Japan 1979,52 281. 14' L. A. Carpino and A. C. Sau J.C.S. Chem. Comm. 1979,514. 14* P. K. Hon C. W. Mak and J. Trotter Inorg. Chem. 1979 18 2916. 143 (a) M. B. Faist and J. T. Muckerman J. Chem. Phys. 1979 71 233; (6)V. I. Osherov and L. V. Poluyanov Teor. i eksp. Khim. 1979,15 3. 144 (a)J. q. Hutchinson and R. E. Wyatt J. Chem. Phys. 1979,70,3509; (b)R. E. Wyatt and R. B. Walker ibid. p. 1501; (c) M. E. Jacox Chem. Phys. 1979 42 133; (d) N. F. Sharnonia and A. G. Kotov Kinetika i Kafaliz 1979 20 233; (e) D. J. Malcolme-Lawes Radiochim. Acfa 1979 26 71; (f)D. Brandt L. W. Dickson L. N.Y. Kwan and J. C. Polanyi Chem. Phys. 1979 39 189. (a)J. P. Sung R. J. Malins and D. W. Setser J. Phys. Chem. 1979 83 1007; (b)H. Lorenz H. G. Wagner and R. Zellner Ber. Bunsengesellschaft phys. Chem. 1979,83 556. 146 G. K. Vasil'ev E. F. Makarov and Yu. A. Chernyshev Fiz. Goreniya Vzryva 1979 14. T. Higashihara Bull. Chem. SOC. Japan 1979 52 2489. J. W. Bevan B. Martineau and C. Sandorfy Canad. J. Chem. 1979 57 1341. 14' 14' F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway of HF and [H,F]’ solvated with a limited number of water molecules have shown that the appearance of new species is related to geometrical restrictions placed on the solvating molecules. 149a Ab initio MO calculations have produced values of Gibbs free energies for some hydrogen fluoride 01igomers~~~’ and a detailed analysis of the structure of liquid HF including co-ordination number and energy distribution functions been carried A brief report on matrix-isolated HF2- last year has been followed by an independent study of the HF2-and DF,- species.In this it is suggested that the formation of the anion involves photodissociation of HF and photoionization of an electron source which gives electrons for capture by F and subsequent combination of HF and F-.’” The recent preparation of iodine azide IN3 as a pure substance has resulted in a detailed investigation of its chemistry being undertaken. This includes addition to olefinic double bonds reactions with metal halides and halogeno-metalates and metal carbonyl complexes.It has been concluded that its pronounced reactivity and its comparative stability are consequences of the polarity of the I-N bond. The iodine has acceptor properties and the N atom of the N3 group acts as a donor. It has been shown that appropriate handling of the compound makes it less dangerous to handle than has been thought During investigations of reactions of chlorodimethylamine with a series of potential alkylating agents it was shown that reaction of NMe2C1 with an excess of iodomethane gave yellow crystals of “Me4] [NMe2(IC1),]. An X-ray structure determination”lb on these crystals has shown that the [NMe,(ICl),]- ion (Figure 13),which contains linear N-I-Cl bonds can be regarded as a pseudo-polyhalide ion related to 15-.Figure 13 Structure of the [NMe2(IC1)21-ion (Reproduced from J.C.S. Dalton 1979 283) ‘49 (a)V. Forero J. I. Fernandez-Alonso and J. Bertran J.C.S. Dalton 1979,254; (b)T. Aoyama and H. Yamakawa Chem. Phys. Letters 1979 60 326; (c)W. L. Jorgensen J. Chem. Phys. 1979,70 5888. 15’ S. A. McDonald and L. Andrews J. Chem. Phys. 1979,70 3134. (a)K. Dehnicke Angew. Chem. Internat. Edn. 1979,18,507;(b)N.W. Alcockand J. F. Sawyer J.C.S. Dalton 1979 283. The TypicalElements 115 Compounds containing organoiodine(II1) have attracted the attention of X-ray crystallographers recently. In most of these compounds the iodine(II1) atoms form three covalent bonds to other atoms in a slightly distorted T-shaped geometry. Virtually all of the known structures also contain weak inter- and intra-molecular co-ordinate bonds at remarkably constant orientation round the iodines.New structures that confirm this overall picture include those of the first p-0x0-iodine species (NO,)PhIOIPh(NO,) (Figure 14),152aphenyIiodine(II1) dia~etate,'~~' Figure 14 Structure of (N03)PhIOIPh(N03) (Reproduced from J.C.S. Dalton 1979 851) already the subject of an earlier independent study and phenyliodine(Ir1) bis(dichl~roacetate).*~~~ The overall geometry about iodine in each case is a pentagonal planar arrangement of three strong and two weak bonds. Vibrational frequencies for HOF and HOCl have been calculated from anhar- monic ab initiolempirical potential energy functions and found to be in good agreement with experimental Force constants rotation distortion constants and mean amplitudes of vibration have been calculated for C102F.'53b Following the recent preparation of BrOF by the reaction of K[BrF,O] with the weak Lewis acids O2AsF6 and HF the BrF20' cation has been obtained by the interaction of bromosyl fluoride with BF and AsF,.The I9F n.m.r. and vibrational spectra of the salts have also been studied.lS4 The vibrational data reported last year for the tetrafluoro-oxohalate(v)anions have been used to calculate mean amplitudes of vibration for the ions.155 A new determination of the standard heat of formation of perchloryl fluoride ClO3F has been determined by hydrolysis in normal NaOH solution. Is' (a) N. W. Alcock and R. M. Countryman J.C.S. Dalron 1979 851; (b) N.W. Alcock R. M. Countryman S. EsperHs and J. F. Sawyer ibid. p. 854. Is3 (a)P. Botschwina Chern.Phys. 1979,40,33; (b)R. Namasivayam and S.Nagarajan Proc. Indian Acad. Sci. 1979 BBA 101. 154 R. Bougon T. Bui Huy P. Charpin R. J. Gillespie and P. H. Spekkens J.C.S. Dalton 1979 6. 155 E. J. Baran Monafssh.,1979 110 715. M. Cartwright and A. A. Woolf J. Fluorine Chem. 1979 13 353. 15' 116 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway The results of a study of the effect of hydration on the ion pairs Li+C104- and KfC104- isolated in argon matrices are consistent with the idea that the C104- ion is only weakly distorted through interactions with either water or ammonia solvent medium and help to establish the general nature of the marked reduction in the strength of contact cation-anion interactions that accompanies Lewis base solvation of the cation.'" Fluorine perchlorate FOClO, prepared by the thermal decomposition of NF4C104 is very pure.Prepared in this way the compound can be manipulated and repeatedly frozen without it exploding. This is contrary to previous experience. It has been shown that FOC103 can add to carbon-carbon double bonds to produce alkyl perchlorates in good yield as in reactions (13) and (14). The formation of two -4s "C CF2=CF2 +FOC103 -CF3CF20C103 (13) -4s "C CF3CF=CF2 +FOC103 -CF3CF2CF20C103+CF3CF(OC103)CF3 (14) 68% 32% isomers in reaction (14) indicates that the 0-F bond in FOClO is of low polarity and suggests that significant positive character for fluorine is unlikely.Since a CF30 group is much less electronegative than an 03C10 group the results imply that contrary to general acceptance covalent hypofluorites such as CF,OF do not contain positive fluorine .Is8 The sluggishness of perbromate reactions is in sharp contrast with its high thermodynamic oxidizing power. This has led to an examination of the reactivity of perbromate towards a number of potentially two-equivalent reductants in aqueous solution. Reaction rates increase in the order N3-<C102-=Se03'-=NOz-<PI'' << S'" s AS"'<Sb"'. In two cases the oxygen transfer that accompanies the reaction has been Ab initio calculations on the ground states of (ClFCl)' and (ClClF)' have been carried out to try to resolve the uncertainty as to whether C12Ff in salts such as C12F'AsF,-and Cl2F+BF4- has the bent C2 symmetry of (ClFCl)' or the asym- metric (ClClF)' structure.It has been concluded that (ClFCl)' is the more stable form. Similar calculations also indicate that (HFCl)' is more stable than (HC1F)'.l6' The kinetics of the initial stage of the thermal reaction of fluorine with chlorine in a flow system to give ClF indicate that the reaction proceeds by a chain mechanism.161" Ozone has been found to inhibit the rate of formation of C1F in the reaction.1616 A high-resolution analysis of the B3n(O') +-X'X+ absorption spectrum of BrF has been carried out,162a and the vacuum-u.v. photoelectron spectra of BrF (X'X+)and IF (X'X)have been recorded and interpreted.'626 The electric dipole moment of IF has been determined by a study of the Stark effect on the hyperfine components of J.Draeger G. Ritzhaupt and J. P. Devlin Inorg. Chem. 1979,18 1808. C. J. Schack and K. 0.Christe Inorg. Chem. 1979 18 2619. 159 E. H. Appelman U. K. Klaning and R. C. Thompson J. Amer. Chem. Soc. 1979,101,929. 16" B. D. Joshi and K. Morokuma J. Amer. Chem. Soc. 1979 101 1714. lbl (a)Yu. I. Petrov F. M. Mukhametshin A. G. Shumikhin and A. D. Stepukhovich Kinetika i Katalir 1978,19,1106;(b)Yu. I. Petrov F. M. Mukharnetshin E. A. Ostapenko and A. D. Stepukhovich ibid. 1979,20 243. (a) J. A. Coxon and A. H. Curran,J. Mol. Spectroscopy 1979,75,270;(b)E. A. Colbourn,J. M. Dyke N. K. Fayad and A. Morris J. Electron Spectroscopy Relat.Phenom. 1978 14. 443. 15' The Typical Elements 117 the J = 1t0 rational tran~iti0n.I~~ Electronically excited ICl has been shown to behave kinetically and stereochemically in a manner similar to a free chlorine atom in its reactions with cis-and trans-1,2-dibr0moethylene.'~~ Reactions of alkali bromides and iodides with fluorine have resulted in the formation of M'BrF2- and M'IF2-. 1.r. spectra of these ion pairs in solid argon have been assigned to the symmetric FXF- and XFF- (X = Br or I) species. The results have been interpreted in terms of reaction scheme (15).16 MX+F2 3 M'XFF-+ M'FXF-+ MF+XF (15) The discovery of the ClF radical several years ago generated considerable interest not only because it was the first 35 valence electron AB radical to be observed but also because unlike previously observed AB radicals it was reported to have D4hrather than C, symmetry.An ab initio molecular orbital study however clearly favours C,,symmetry for the Solubilities of oxygen and nitrogen in ClF under pressure have been deter- mined.167a The zero-point average structures of gas-phase BrF5167b and IF5167C have been determined by analysis of electron diffraction data and rotational constants obtained from microwave spectroscopy. A new patent for the preparation of IF from molten iodine and gaseous fluorine at 120-160 "C has been taken out.168 The synthesis of a stable organic fluoroperiodinane last year opened up the possibility of a new area of iodine pentafluoride chemistry.This 'tamed' analogue of IF5has now been utilized as a selective reagent for the oxidation of primary and secondary amines or alcohols with a-hydrogens to aldehydes or ketone^.'^' The temperature variation of the central-atom hyperfine interaction in the halogen hexafluoride radicals has been studied in various 4 Group VIII Recent aspects of the chemistry of xenon and especially its reactions with the pentafluoro-oxoselenate and pentafluoro-oxotellurate groups has been reviewed. 125 Expansion of mixtures of BF with Ar N2 or CO through a supersonic nozzle has produced van der Waals complexes which have been studied by microwave spec- troscopy. Dipole moment calculations on the Ar.BF3 complex indicate that it contains BF3 in a planar configuration.The energy of complexing estimated at 0.04 kJ mol-' is one four-hundredth of that in OC.BF3 and N2.BF3."ln The border- line between the chemical bond and a molecular interaction is a loose one and recent work on matrix-generated pentacarbonyls has prompted an ab initio investigation of 163 K. P. R. Nair J. Hoeft and E. Tiemann Chem. Phys. Letters 1979,60 253. 164 S. Datta J. I. Brauman and R. N. Zare J. Amer. Chem. SOC.,1979 101 7173. J. H. Miller and L. Andrews Inorg. Chem. 1979,18,988. 166 S. P. So and W. G. Richards J.C.S. Faraday It 1979,75 55. 167 (a)V. F. Sukhoverkhov V. F. Garanin and L. G.Podzolko Doklady Akad. Nauk S.S.S.R.,1979,246 1379;(b)R. K. Heenan and A. G.Robiette J. Mol. Structure,1979,54,135;(c)R. K. Heenan and A. G. Robiette ibid.1979 55 191. 16' J. T. Lileck U.S. P. 4 108 966 423466 (Chem.Ah. 1979 90 089 568). 169 R. L. Amey and J. C. Martin J. Amer. Chem. SOC.,1979 101 5294. A. R. Boate J. R. Morton and K. F. Preston J. Chem. Phys. 1979,71 388. 171 (a)D. R. Armstrong Inorg. Chim. Acta 1979,33,177;(b)J. Demuynck E. Kochanski and A. Veillard J. Amer. Chem. SOC.,1979 101 3467. F. A.Hart A.G. Massey P.G. Harrison and J. H.Holloway the possibility of bond formation between [M(CO),] (M = Cr or Mo) and noble gases (Ar Kr or Xe). The stabilization energy for [Mo(CO),Kr] has been estimated as 10.5 kJ mol-' although this is thought to be underestimated by as much as 32 kJ m01-l.'~~~ New krypton and xenon inclusion compounds CdPt(CN)6 .1.046Kr and CdPt(CN),.l.l28Xe have been obtained by growing crystals of the host in the presence of the noble gas at 64 bar.*72 A semi-empirical valence-bond method for calculating isotropic and anisotropic hyperfine interaction constants in diatomic halogen anions and noble gas mono- halides has been extended to the linear triatomic Kr-F-Kr species.Estimates of the Kr-F bond distance and the electron charge distribution have been made.173n The well depths of XeF- and XeCl- have been estimated from differential scattering Excited ArF" KrF" and XeF* species have been observed in a.c. current electric discharges in binary mixtures of SF6 and a noble gas or ternary mixtures of rare gases with SF6.173c The formation kinetics of the formation of ArCl' ArI' KrF' and KrCl' in a steady-state low-pressure hollow cathode discharge have been An ESCA study of XeF has been performed to high statistics and satellites observed on the low-kinetic-energy side of the xenon 3d and 4d primary photolines have been attributed to shake-up.The nature of the satellite lines has been identified using theoretical SCF-X,-SW Differences in nucleus lone-pair and nucleus bond-pair attraction have been used to explain co-ordination geometries about XeF, XeF, and XeO,.'" Xenon difluoride continues to find application as a fluorinating agent. New examples include the BF3 .Et20-initiated fluorination of norbornene with XeF in CH2C12 which selectively produces the novel 2-endo- 5-exo- and 2-exo- 5-exo- difluoron~rbornane,~~~" and the reaction of aryl trifluoromethyl sulphides and selenides p-RC,HsZCF (Z= S R = H C1 or 0,N; Z = Se R = H Br Me or CF,) which give p-RC6H4ZF2CF3 in quantitative yield.176b A report of the reaction of XeF with [Re2(CO)lo] in perfluoro-l,3-dimethylcyclohexaneconcludes that the product is [Re(C0)3F2]4176C although the properties of the compound produced clearly indicate that it is Re(CO),F.ReF5.177 Since noble-gas chemistry was initiated in 1962 many attempts have been made to produce compounds with a carbon-xenon bond. Recent experiments in which xenon difluoride was bled into the tail of a trifluoromethyl radical plasma produced a volatile waxy white solid which was trapped at -196 "C. The new compound is thought to be Xe(CF3)2. It has a half-life of -30min at room temperature and a vapour pressure significantly greater than that of XeF,.1.r. spectra electron impact 172 M. Kamper M. Wagner and A. Weiss Angew. Chem. Znternat. Edn. 1979,18,487. 173 (a)F. J. Adrian and A. N. Jette Chem. Phys. Letters 1979,64,555;(b)C.de Vreugd R. W. Wijnaendts van Resandt and J. Los,ibid. 1979,65,93;(c)A. K. Shuaibov and V. S. Shevera Zhur. tekh. Fiz. 1979 49,1747; (d)I. Kuen and F. Howorka J. Chem. Phys. 1979,70,595. J. S. Tse D. J. Bristow G. M. Bancroft and G. J. Schrobilgen Znorg. Chem. 1979 18,1766. S. Anderson Acta Cryst. 1979 B35,1321. 17' (a) S. A. Shackelford FJSRL-TR-78-0008 Order No. AD-A061909 50 PP. NTIS. Gov. Rep. Announce. Index (U.S.) 1979,79 (7) 89 (Chem. Abs. 1979,91,009 965); (b)Yu. L. Yagupol'skii andT. I. Savina Zhur. org.Khim. 1979,15 438; (c)S. N.Misra Indian J. Chem. 1979 17B,101. 17' D. M. Bruce A. J. Hewitt J. H. Holloway R. D. Peacock and I. L. Wilson J.C.S. Dalton 1976,2230. The Typical Elements mass spectra and chemical ionization mass spectra have been obtained as well as fluorine analysis which are consistent with the postulated form~lation.~'~ In 1978 Xe(OTeF,) was reported and now Xe(OTeF& has been prepared for the first time by reaction of XeF6 with B(OTeF,) in perfluoro-n-pentane at -40°C [reaction (16)] The red-violet compound appears to be monomeric and de- composes to Xe(OTeFS) and FsTeOOTeFS either thermally at -10 "C or by exposure to daylight at temperatures as low as -230°C. Hydrolysis results in the formation of OXe(OTeF,) which can also be obtained by reaction of XeOF with B(OTeF5)3.Attempts to prepare the krypton analogue resulted in the formation of FSTe00TeFs.179 L. J. Turbini R. E. Aikman and R. J. Lagow J. Amer. Chem. Soc. 1979,101 5833. 179 D. Lentz and K. Seppelt Angew. Chem. Internat. Edn. 1979 18 66.

ISSN:0260-1818    

DOI:10.1039/IC9797600084

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

3 The Transition Elements By F. A. HART and P. THORNTON Department of Chemistry Queen Mary College Mile End Road London El 4NS J. NEWBERY Department of Chemistry Goldsmith's College New Cross London SE 14 6NW Part I Scandium Yttrium the Lanthanides and the Actinides By F. A. Hart 1 Scandium Scandium chemistry has again been almost absent this year. The metal is of course very expensive but further work on this element could well yield results of considerable interest. Fuller details have appeared' concerning 'H lineshape n.m.r. studies on the exchange of OP(OMe) with [SC{OP(OMe)3}6]3+ in CD,CN sym-C2H4C12 or CD3N02. In the first two solvents the rate is independent of added ligand (CD3CN AHf = 29.8 kJ mol-'; AS* = -111 J K-' mol-') but in CD3N02 exchange rates are first order in each reactant.Similar studies have been made on analogous (Me0)2P(0)Me systems2 When Sc(C104),.6H20 is heated in ethanol with N2H4 and diacetylpyridine a yellow air-stable solid [SCL(H,O)~](C~O~), * 4H20 is formed, L being the 2 :2 macrocylic quadridentate template condensation product. Though six nitrogens are in the ring only four of them are geometrically able to co-ordinate. See also references 38 and 39. 2 Yttrium and the Lanthanides A review has appeared4 on the electronic absorption spectra and structure of lanthanide co-ordination compounds in solution; it has 255 references up to 1977. Complexes are formed in the vapour phase between SmC12 or SmCl and AlCl,. When the compounds were heated together at -750 K absorption spectra showed that the reaction SmC13(s)+ 1.5A12C16(g)+ Sm(A1C14),(g) had taken place with AH = 6.7 kcal mol-' and AS = -1.0 cal K-'mol-'.This paper also contains a general method for preparing LnCl (also NdBr3 ThC14 UCl, and UCI,) by the action of AlCl on Ln203 at 300 "C in a quartz tube; vapour transport purifies the product.' There has also been a theoretical study of the use of D. L. Pisaniello S. F. Lincoln and E. H. Williams J.C.S. Dalton 1979 1473. D. L. Pisaniello and S. F. Lincoln Znorg. Chim.Acta 1979 36 85. ' W. Radecka-Paryzek Znorg. Chim. Acta 1979 35 L349. 'K. B. Yatsimirskii and N. K. Davidenko Coordination Chem. Reu. 1979 27,223. G. N. Papatheodorou and G. H. Kucera Inorg. Chem. 1979,18 385. 121 F. A. Hart P.Thornton and J. Newbery spectrophotometry to characterize gas complexation reactions of lanthanide and actinide halides with Group I11 halides6 The temperature-dependent molar absorptivity is explained in terms of a temperature-dependent linewidth and ground- state population as well as the existence of different molecular species. A convenient synthesis of tervalent and bivalent lanthanide halides (as THF solvates) is by warming mercuric halides with the lanthanide metal in THF.7 Two crystal structures of simple lanthanide compounds have appeared; LaC13.7H20 has structure (l),' c1 and Ce(OH)3 is a tricapped trigonal prism.g Nd4' may be stabilized by incorporation into perovskite host lattices of BaXO (X = Ce Pr Th or Zr) by heating in air at 1250-1400 "C.Concentrations of up to 30% are obtained for X = Ce." The redox behaviour of Eu3+ in exchanged zeolites (which are active catalysts for cracking fuel oil) has been followed by emission spectroscopy." After degassing at room temperature excitation at 390 nm gives the characteristic 'Do-P 7Ffl600 nm emis- sion of Ed+ but degassing at 300 "C gives 02,and on exciting at 345 nm the 4f -+ 5d 450 nm emission of Eu2' is observed. This is reversible on cooling and addition of water. Most work has been concerned with lanthanide complexes and it is convenient to divide this into two parts (a)conventional ligands and (b) crowns and cryptates which we take in that order. In an interesting paper," the use of direct excitation of the 7Fflstates of Eu3' or Tb3+ by a pulsed dye laser with determination of the resulting luminescent emission lifetimes gives a direct indication of the number of co-ordinated water molecules in solution or in solid samples.This is because coupling to the OH vibrational overtones provides the main deactivation route. The relationship was established using a series of solid complexes containing 0-9 co-ordinated H20molecules. The results indicate that aqueous Tb3' contains [Tb(H20),I3' whereas for Eu3' there is an equilibrium between the nona- and deca-hydrates. 13'La (I= 7/2 99.9%) has 300 times the n.m.r. sensitivity of 13C but suffers line-broadening by quadrupolar relaxation. It has been used13 to investigate inner- and outer-sphere complexing with SCN- and C1-. Chemical shifts (which vary from that of La3'(aq) by up to 100p.p.m.) indicate that inner-sphere complexing starts at about 1M for NCS- and 5M for C1-.ti J. P. Hessler J. Phys. Chem. 1979,83 2631. ' G. B. Deacon and A. J. Koplick Znorg. Nuclear Chem. Letters 1979,15,263. A. Habenschuss and F. H. Spedding Cryst. Structure Comm. 1979,8 511. S. F. Mullica J. D. Oliver and W. 0.Milligan Actu Cryst. 1979 B35 2668. lo G. Brauer and H. Kristen 2.anorg. Chem. 1979,456,41. '' T. Arakawa T. Takata G.-Y. Adachi and J. Shiokawa J.C.S. Chem. Comm. 1979,453. l2 W. Dew. Horrocks and D. R. Sudnick J. Amer. Chem. SOC.,1979,101 334. l3 P. L. Rinaldi S. A. Khan G. R. Choppin and G. C. Levy J. Amer. Chem. SOC.,1979 101 1350. The Transition Elements Ytterbium trichloride reacts with secondary amines and CO in hydrocarbon solvents to give the first lanthanide dialkyl~arbamates,'~ Yb(02CNR2)3 (R =Et or Pri).The Pr' compound is tetrameric (X-ray) with different types of dialkyl- carbamato-group bidentate to one Yb bridging two Yb or co-ordinated to three Yb. The observation of spin-spin co~pling'~ between 89Y and 31P in [YL4]- [L = S2P(OEt),] is interpreted as evidence for covalent bonding the magnitude of the coupling constant being about the same as in RhL3 and PtL,. This result is extrapolated to the analogous lanthanide complexes and the intensities of observed f +f transitions in lanthanide complexes are discussed in terms of lowering of energy of excited states involving 5d orbitals leading to greater configuration interaction and hence greater oscillator strength.What is described as the first 11-coordinate complex with an organic-type ligand (actually that palm went last year to [Ce(N03)4(H20)2(4,4'-bipyridyl)]-) has been synthesized and has undergone X-ray determination.16 La(N03)3L [L = (2)] is a pentagonal bipyramid with bidentate nitrates in the axial positions (La-N = 2.769-2.790 A La-0 = 2.507-2.648 A). The ligand (2) is quinque-dentate using three nitrogens and two oxygens. KCeFe(CN),.4H20 has nine-co-ordinate Ce3' in trigonalprismatic co-ordination to six nitrogens (Ce-N = 2.556 A all from different [Fe(CN)6]4- entities) with three H20 at face-centring positions the fourth H20being H-bonded to the co-ordinated water." A series (La Nd Sm Gd Ho and Yb) of complexes [LnL3(H20)3](N03)3 [L =4-pyridyl-C(O)NHNH,] has been reported as has the X-ray structure of the Sm compound.18 The irregular nine-co- ordination involves bidentate L using the amide oxygen and the NH2 nitrogen; the pyridine nitrogen is not co-ordinated.Three water molecules complete the sphere. The structures of [Ln(pyridine N-~xide)~](ClO~)~ (L=La or Nd) have been compared.lg Both have square-antiprismatic co-ordination (La-0 = 2.493 2.500 A; NOLa = 127.7-136.3'; Nd-0 = 2.383-2.447 A; NONd = 129.0-133.3') but the orientation of the pyridine rings is somewhat different. The catechol complex Na4[Ce(02C6H4)4].21H20 has on the other hand dodecahedra1 co-ordination with Ce-0 =2.357 and 2.362 A.2o The interesting terdentate phosphoryl ligand L [L =Me2NP(0){N(Me)P(O)(NMe2)2}2], forms stable nine-co- ordinate complexes [LnL3](C104)3 (Ln = Y or La-Lu except Pm) whose detailed l4 D.B. Dell'Amico F. Calderauo and F. Marchett J.C.S. Chem. Comm. 1979 1103. Is A. A. Pinkerton and W. L. Earl J.C.S. Dalton 1979 1347. l6 J. E.Thomas R. C. Palenik and G. J. Palenik Znorg. Chim. Acta 1979,37 L459. D. F. Mullica W. 0.Milligan and J. D. Oliver Znorg. Nuclear Chem. Letters 1979 15 1. '* L. B. Zinner D. E. Crotty T. J. Anderson and M. D. Glick Inorg. Chem. 1979,18 2045. l9 A. R. Al-Karaghouli and J. S. Wood Znorg. Chem. 1979,18 1177. 2o S.R. Sofen S. R. Cooper and K. N. Raymond Znorg. Chem. 1979,18,1611. 124 F. A. Hart P. Thornton and J.Newbery structures show dependence on ionic radius.’l The complexes are inert with respect to intermolecular ligand exchange in solution which again demonstrates the affinity of the phosphoryl group for lanthanide ions.The papers on various types of macrocyclic complexes concern mainly crown ethers and cryptates but include two concerning all-nitrogen macrocycles. Satellite structure in the ESCA spectra of phthalocyanine complexes LnPcHPc (Ln =La Ce Pr Nd or Gd HPc =phthalocyanine) and MPc2 (M =Th or U) have been studied and interpreted in terms of the hypothesis that half-filled f-orbitals are an important factor in satellite intensity changes along the f-series.22 Very stable complexes [Ln(NO,),L] with a sexadentate N-donor macrocycle have been by a 2 :2 template condensation of 2,6-diacetylpyridine with 1,2-diaminoethane to give the tetraimine.The complexes do not dissociate or exchange the organic ligand in water and are stable towards aqueous OH- or F-. The Ce complex shifts the n.m.r. resonance position of added aqueous acetate. The La complex which has two bidentate NO on one side of the slightly folded macrocycle and one on the opposite side is thus 12-co-ordinate (La-N =2.672-2.764 A La-0 =2.689-2.767 A). Discussion of crown ether complexes begins with the smallest rings. A series of hygroscopic complexes Ln(12-~-4),(ClO,)~ [12-c-4 =(3); dibenzo-18-c-6 =(4) and r”) Qn O) ao 0 0 OW0 I \ (3) (4) others are named analogously; Ln=La Pr Eu Ho Er Tm or Yb] has been prepared.’ They are believed to have a sandwich structure analogous to the Na complex.The two-peak highly shifted ‘H n.m.r. spectrum in CD,CN solution supports this view which is reasonable because of the small cavity size of the ligand. The nitrate ion favours 1:1 complex formation owing to its greater co-ordinating ability. A number of complexes of PrXJ (X =NCS C1 or ClO,) with 15-c-5 and 12-c-4 have been described.” They include 2 :1complexes Pr(15-c-5),(C104) and Pr(l2-~-4)(15-~-5)(ClO,)~.series of complexes La(H20),(dibenzo-18-c-6) A (C104)3 (Ln =La Ce Pr Nd Sm Eu Dy or Ho x =0; Ln =Er or Yb x =1)has been prepared26 in acetonitrile. X-Ray examination of the Sm compound shows 10-co-ordination with one bidentate ClO (Sm-0 =2.64 A) on the smaller side of the slightly folded crown and two unidentate ClO (Sm-0 =2.36 A) on the other side; Sm-O,,,, =2.42-2.59 A.The Sm the orange Eu and the yellow Yb 21 R. P. Scholer Inorg. Chim. Actu 1979 35,79. 22 K. Tatsumi K. Kasuga and M. Tsutsui J. Amer. Chem. SOC. 1979 101 484. 23 J. D. J. Backer-Dirks C. J. Gray F. A. Hart M. B. Hursthouse and B. C. Schoop J.C.S. Chem. Comm. 1979,774. 24 J. F. Desreux and G. Duyckaerts Inorg. Chim. Actu 1979,35 L313. 25 J.-C. G. Bunzli D. Wessner and H. T. T. Oanh Inorg. Chim. Actu 1979,32 L33. ”M. Ciampolini N. Nardi R. Chi S. Mangani and P. Orioli J.C.S. Dulfon 1979 1983. The Transition Elements 125 complex have broad bands in the visible probably from ligand+metal charge transfer from orbitals of the OC2H40 groups. The much larger macrocycle dibenzo- 30-c-10 gives complexes with lanthanide perchlorates formulated Ln(crown)- (H20)x(MeCN)y(C104)3 (x = 0-2 y = 1.5 or 2) but no definitive structural data are available.27 Turning to cryptate ligands two further structures of complexes of 2,2,2-cryptate [this is N(CH2CH20CH2CH20CH2CH2)3N, and other similar ligands are named analogously] have appeared.The first is [Sm(~ryptate)NO~]~'[Srn(NO~)~H~O]~-where the 10-co-ordinate cation has one bidentate NO inserted between two of the dioxaoctane chains of the enveloping cryptate2* (Sm-N = 2.748 2.779 A Sm-Ocrypt = 2.441-2.566 A Sm-Onitrate= 2.484 2.502 A). This contrasts with the previously reported analogous complex of the larger La cation [La(crypt) (N03)2]+ which has two such insertions giving 12-co-0rdination.~~ In the Sm complex the anion has the rare 11-co-ordination.Fuller details of the structure of [Eu(~rypt)(ClO~)](C10~)~,MeCN The struc- noticed last year,,' have a~peared.~' ture is similar to [Sm(~rypt)NO~]~+ and has Eu-N = 2.64 2.70 A Eu-Ocrypt = 2.44-2.52 A Eu-Operchlorate= 2.67 2.71 A; The weaker bonding of c104-compared with NO3- is quite marked. In the same paper is reported a series of complexes Ln(2,2,2-~rypt)(H~O)~(MeCN)~(MeC0NH~),= La Ce Pr (C104)3 (Ln Nd Sm,Eu Dy Ho Er or Yb; x = 0 or 1,y =0 i,or 1 z = 0 or 1). An interesting 'H n.m.r. of the series of lanthanide 2,2,1-cryptate complexes Ln(crypt)X3 (X = C1 NO3 or C104 Ln = La-Yb) has given conformational information. First a plot of paramagnetic shift us. Bleaney's anisotropy constant gives a good straight line and hence [Ln(crypt)I3+ are all isostructural in D20.Secondly a single conformation is either stable or is dynamically favoured because the same AMXY pattern for all four NCH2CH20CH2CH20CH2CH2N protons is observed. A few papers on lanthanide shift reagents and related topics show some continued interest in this area now a decade old. Aqueous solutions of EuC13 with chiral a-hydroxy-acids have been shown to resolve the 'H n.m.r. resonances of racemic mixtures e.g. of R,S-lactate and of enantiotopic protons e.g. in gly~ollate.~~ In the shift reagent adduct [E~(Me~CCOCHCOCMe,)~(3-methylpyridine)~] the aromatic rings are in their rotation restricted to one plane by the three bulky chelate groups. A variable-temperature 'H n.m.r.of the paramagnetic shifts has shown that solvation plays a considerable part in the resulting conformational equilibrium because in CC12F2 AHe = 1.O kcal mol-' and AS@ = 8 cal K-' mol-' whereas in CS AHe = 4.3 kcal mol-' and AS@= 26 cal K-' mol-'. The rather flexible molecules adenosine-2'-monophosphateand -3'-monophosphate have each been found to be in conformational equilibrium in aqueous solution using lanthanide shift and relaxation probes. The lanthanides (Eu and Pr) bind to bidentate pho~phates.~' 27 M. Ciampolini and N. Nardi Inorg. Chim. Acta 1979 32 L9. 28 J. H. Burns Inorg. Chem. 1979 18 3044. 29 F. A. Hart M. B. Hursthouse K. M. A. Malik and S. Moorhouse J.C.S. Chem. Comm. 1978 549. 30 M. Ciampolini P. Dapporto and N. Nardi J.C.S. Chem. Comm.1978 788. 31 M. Ciampolini P. Dapporto and N. Nardi J.C.S. Dalton 1979 974. 32 0.A. Gansow D. J. Pruett and K. B. Triplett J. Amer. Chem. SOC.,1979 101,4408. 33 J. Reuben J.C.S. Chem. Comm. 1979 68. 34 R. E. Cramer R. B. Maynard and R. Dubois J.C.S. Dalton 1979 1350. 35 C. F. G. C. Geraldes J. Magn. Resonance 1979.36 89. F. A. Hart P. Thornton and J. Newbery Eu(C3F7COCHCOBut) forms 1:1 adducts with [C~(ket)~] (ket = acac or MeCOCClCOMe) where the Co3' ion shares a triangular face of three oxygen atoms from three different (ket) ligands with the Eu3' ion. The associative equilibrium is slow on the n.m.r. time-scale and for the MeCOCClCOMe compound AH*= 61 kJ mol-' and AS*= -1 1 J K-'mol-'. The rate-determining step is unimolecular dissociation of the add~ct.~~ Emission titration studies (variation of intensity of the 'Do+7Fnfluorescence with the nature of the complex) have been used to study stability constants and stoicheiometry of various europium shift reagent adducts with alcohols and amines.In most cases 2 1adducts were obtained and where K and K2 were both measurable K2>K1[e.g. EU(BU'COCHCOBU')~-C~H~NH~; log Kl = 2.34 log K2= 5.001 indicating a co-operative mechanism of as~ociation.~' Turning finally to the organolanthanide area substantial progress has been made with alkyl-bridged complexes. A variety of these air-sensitive compounds [(q,-C5H5)2M(p-R)2AlR2] (M = Sc Y Gd Dy Ho Er Tm or Yb R = Me; M = Sc Y or Ho R = Et) have been prepared38 by reaction of [M2C12(C,H,),] with LiAlR or MgAl2Rs.The structure of the compound where M = Yb R = Me shows both metal atoms in approximately tetrahedral environments with Yb-CCpd = 2.61 A Yb-C = 2.59 A. An n.m.r. lineshape study gave for the bridge-terminal site exchange process for M = Y R =Me a value of AG* = 15.9 kcal mol-' at 392 K. These complexes react with ~yridine~~ or in the to give [M2(q5-C5H5)4(pMe)2] case of M = Sc [S~(q~-C,H~)~(Me)pyl. X-Ray crystal structures (M = Y or Yb) confirm the bridged stucture with Y-CCpd = 2.655 A Y-C = 2.545 A Yb-CCpd= 2.613 A Yb-C = 2.51 1A. An interesting preliminary report has appeared4' of mixed-ligand organo-complexes of the anion of MeCOCH= C(Me)NHPh (HL). HL reacts with Yb(CsH5) and YbCl(C,H,) to give yellow volatile YbL(C5H5)2 and red-brown volatile YbL(C,H,)Cl respectively.The latter reacts with more LH to give [YbL2(C5H5)]. Co-condensation of Er metal (or other lanthanides) and hex-3-yne at -196°C gave a brown solid which will hydrogenate hex-3-yne to cis-hex-3-ene at room temperature and pressure. The brown solid is believed to be partially E~~(C~HIO)~.~' 3 The Actinides By far the greatest amount of work has been done on uranium complexes with the U022+ ion again a favourite. We will proceed in ascending sequence of oxidation state. The 'difficult' ion U3' has received further effective study. NH4UC14.5H20 is a useful starting material for the preparation of complexes and its reaction with the diamides Me2NCO(CH2),CONMe2 (n= 1-4) or R2NCOCH2CMe2CH2CONR2 (R=Me or Et) in dry ethanol in presence of appropriate anions gives 36 L.F. Lindoy and H. W. Louie J. Amer. Chem. SOC.,1979,101 841. 37 H. G. Brittain J.C.S. Dalton 1979 1187. 38 J. Holton M. F. Lappert D. G. H. Ballard R. Pearce J. L. Atwood and W. E. Hunter J.C.S. Dalron 1979,45. 39 J. Holton M. F. Lappert D. G. H. Ballard R. Pearce J. L. Atwood and W. E. Hunter J.C.S. Dalton 1979 54. 40 G. Bielang and R. D. Fischer Inorg. Chim. Acta 1979 36 L389. 41 W. J. Evans S. C. Engerer P. A. Piliero and A. L. Wayda J.C.S. Chem. Comm. 1979 1007. The Transition Elements 127 [U(diamide),]X3 (X = BPh or PF6) as air-sensitive black mauve or green solids., The electronic spectra are explained in terms of nephelauxetic effects on the f +d transitions; i.r.spectra indicate eight-co-ordination the anions being unco-ordinated. By analogous methods several other complexes were pre- pared,, namely UL3X3 or UL4X3 [L = (EtO)zP(0)(CH2),P(O)(OEt)2 (n = 2 or 3) (Me,N),P(0)0P(0)(NMe2), Me,NCOOCH,P(O)(OEt), or 1,l'-methyl-enebis(pyrro1id-2-one)]; also obtained were 1 1 complexes with the crown ethers 18-c-6 dicyclohexyl-18-c-6 and 15-c-5 and with the 2,2,2-cryptate. Anions X were PF6 BPh, or C1. Crown ether complexes of U3+ may also be obtained though not analytically pure by reduction of UCl with NaH in THF followed by addition of 18-~-6.~~ A convenient method for preparation of U3+ compounds including complex halides is by reduction of UCl solutions in HC02H or MeCN in the presence of a little EtCO,H by zinc amalgam.45 Thus prepared were M2UCls MU,Cl (M = K Rb NH, Ph4P or Ph4As) U(HCO,), and UPO,.Red volatile monomeric [U{N(SiMe,),},] has been by the reaction of NaN(SiMe,) with Na naphthalenide-reduced UCl in THF. It is thought to be pyramidal like the analogous lanthanide compounds. Remarkably it does not form addition compounds with CO Me,P Me,PO THF Me3N pyridine Bu'NC or Bu'CN. Trimeric [U3C13(~~-Me5C5)6] prepared e.g. by the reduction of [UC12(Me5C5)2] with Bu'Li in ether at -78 "C has a triangular chloro-bridged D3,,structure (U-C = 2.76 A U-Cl= 2.90 A ClUCl= 84-5" UClU = 155.5"). It forms 1 1 adducts with pyridine or THF which have SCH3 = -5 in 'H n.m.r. The linewidth is broad 40-100 Hz. Exchange with excess base is rapid.,' Turning to the 4 + oxidation state and beginning with non-complex compounds the gas-phase ion chemistry of U(BH4) has been studied by ion cyclotron resonance spectrometry.A value for AH0f,298 of -7k 14 kcal mol-' was The crystal of Np(VO,) has -V-0-V-0 chains each V being also linked to two other 0atoms and the Np being eight-co-ordinated to oxygen at an average distance of 2.32 A. Uranium(1v) fluoroalkoxides may be easily prepared; thus UC1 and NaOC(CF,) in THF give lavender [U(OC(CF,),} (THF),] m.p. 213 "C (decomp.) volatile and ether-soluble. Blue-green [U{OCH(CF,),} (THF),] may be prepared similarly.50 A number of papers have appeared which concern cyclopentadienyl and related complexes. Some chloro-cyclopentadienyl-tripyrazylborates [U(Cp)* C1 (HBpz3),] (x + y + z = 4) have been characterized and are stable against disproportionation as are their Ph3P0 adducts such as [U(Cp)Cl2(HBpz3)Ph3P0] whereas the cor-responding dipyrazylborates are not.A number of thorium complexes such as [Th(Cp)Clz(Bpz4)] are also de~cribed.~' The discussion regarding UC12(Cp) has 42 J. I. Bullock A. E. Storey and P. Thompson J.C.S. Dalton 1979 1040. 43 J. I. Bullock and A. E. Storey Znorg. Chim. Acta 1979 36 L399. 44 D. C. Moody R. A. Penneman and K. V. Salazar Znorg. Chem. 1979,18,208. '' J. Droidzyhski Inorg. Chim. Acta 1979 32 L83. 46 R. A. Andersen Znorg. Chem. 1979 18 1507. 47 J. M. Manriquez P. J. Fagan T. J. Marks S. H. Vollmer C. S. Day and V. W. Day J. Amer. Chem. SOC. 1979,101,5075. 48 P. B. Armentrout and J. L.Beauchamp Znorg. Chem. 1979 18 1349. A. Tabuteau A. Cousson M. Pages and M. Gasperin Acta Cryst. 1979 B35,2000. R. A. Andersen Znorg. Nuclear Chem. Letters 1979 15 57. 51 K. W. Bagnall A. Beheshti J. Edwards F. Heatley and A. C. Tempest J.C.S. Dalton 1979 1241. 128 F.A. Hart P. Thornton and J. Newbery X-Ray powder i.r. n.m.r. and electronic spectra indicate that it is really [UCl(Cp),] +[UCl,(Cp)( 1,2-dimethoxyethane)l; it was previously thought to be [u(cp)3]2[uc16]. The X-ray structure of the analogous [UC13(MeC5H4)(THF)2] tends to support the new view. The uranium is pseudo-octahedral with two cis-THF and three mer-C1 (U-C =2.692-2.737 A U-Cl =2.614-2.631 A U-0 = 2.449-2.451 A).52 The Mossbauer isomer shifts have been measured for 16 compounds of 237Np of the types [Np(Cp),OR] and [NP(CP)~R] where R is various alkyl or aryl groups.The isomer shift depends on the shielding of the 6s orbital by inner orbitals principally 5f,and a covalency series can be obtained according as electron density is contributed by the R or OR ligand. Thus isomer shifts (cm s-l) of 0.27(Bu") 0.86(Bu') 0.79[OCH(CF,),] and 1.4(Cl) are among those An efficient one-flask synthesis has been devised5 for substituted uranocenes i ether 25°C 2BuLi +C8Hs %1,l'-di-n-butyluranocene(50%) 11 UCId-THF The allyls U(q3-C3H5)2(0R) (R=Et Pr' or But) have been prepared from [U(C3Hs)4] and ROH. They are dimeric in toluene but monomeric in THF. The crystal structure of [(PriO)(q3-C3H5)2U(p- has fairly OPri)2U(q3-C3H5)2(OPr')l similar U-C distances (2.682 2.651 2.661; 2.644 2.698 2.736 A) and angles (CCC= 146.0"; 144.1") in the two crystallographically different ally1 groups; U-Ob =2.271 2.413 8 and U-O,,, =2.056A.55 The chloro-silylamides MClL3 [M=Th or U; L=N(SiMe3),] made by the action of NaN(SiMe,) on MC14 react with Me,Mg or MeLi to give the correspond- ing methyls MMeL3 and with LiBH4 to give the borohydride.The X-ray structure of [Th(BH,)L,] has Th-N =2.32A NThN = 115.9",and a terdentate BH4 (deduced from the Th-B distance 2.61A).56The hydrides MHL3 are also produced by the action of NaL on MClL3 in THF or the deuterides MDL3 are obtained if perdeu-terio-THF is used. They give CHC1 and MClL3 if treated with CCl,. They are -~ These complexes soluble in pentane; v~ = 1430cm-' and VTh-H = 1480~m-'.~~ show very interesting behaviour when treated with D2in pentane All the H atoms in the molecule including the methyl hydrogens are deuteriated.The hydrides lose H at 180-190 "C and this is reversible. N.m.r. evidence indicates that this H2 loss proceeds by formation of a MN(SiMe3)SiMe2CH2 four-membered ring. A few papers have appeared concerning Uv. Crystals of a-UF5 and U2F9 have been obtained by reaction of UF6 and SO at 160"C and the single-crystal X-ray structures confirm the previous powder analysis with UF as a six-co-ordinate chain (U-F, =2.235A U-F,,, = 1.995A). U2F9 has a nine-co-ordinate three-dimen- sionally bridged structure with U-F =2.19-2.40 A. Absorption spectra of U2F9 indicate that conventional U'" and Uv ions are In an extensive study of Uv " R.D. Ernst W. J. Kennelly C. S. Day V. W. Day andT. J. Marks,J. Amer. Chem. Soc. 1979,101,2656. 53 D. G. Karraker and J. A. Stone Inorg. Chem. 1979 18 2205. 54 J. T. Miller and C. W. de Kock Inorg. Chem. 1979,18 1305. " M. Brunelli G. Perego G. Lugli and A. Mazzei J.C.S. Dalton 1979 861. 56 H. W. Turner R. A. Andersen A. Zalkin and D. H. Templeton Znorg. Chem. 1979 18 1221. s7 H. W. Turner S. J. Simpson and R. A. Andersen J. Amer. Chem. Soc. 1979,101 2782. '~3 S. J. Simpson H. W. Turner and R. A. Andersen J. Amer. Chem. SOC., 1979,101,7728. 59 P. G. Eller A. C. Larson J. R. Peterson D. D. Ensor and J. P. Young Inorg. Chim. Acra 1979,37,129. The Transition Elements 129 halogeno-complexes salts of [ux,]-(X = C1 or Br) or their mono-Ph3P0 adducts react with anhydrous oxygen-free EtOH to give salts of [U&(OEt)2]- or to give [UX3(0Et),(Ph3PO)].Hydrolysis of NEt4[UC14(0Et),] or the action of AS203 on NEt4UC16 in non-aqueous solvent yields (NEt,),[UOCl,]. The fluoro-complexes NEt4[UF6] and (NEt4)'[UF7] have also been characterized. Studies of i.r. spectra include one involving '*O substitution.60 Although polymeric when solid p-UF dissolves in solvents L (L=DMF DMSO MeCN or PhCN) and disproportionates into [UF4L,][UF6] (n = 3 or 4).61 As usual most studies of U"' deal with the uranyl ion. Those that do not include the report6' of the reaction between UF,O and SbFs in solvent SbF5 or HF to give yellow-orange UF40(SbF,) (x = 1-3). An X-ray of the (x = 2) compound shows a fluorine-bridged network in which U is surrounded by a pentagonal bipyramid of oxygen and six fluorines four fluorines being bridging to octahedral SbF,'groups in which two fluorines are bridging.The 19F n.m.r. spectrum in SbF5-CF2ClCF2Cl revealed fluorine exchange processes occurring even at -100"C. The presence of thermally unstable [UF50Me] after UF6 is treated with MeOH in CFCl at -90 "C has been demonstrated by 'H 13C and 19F n.m.r.63 In an interesting paper6 laser-induced isotopic enrichment has been obtained using [U(OMe)6]. In this technique preferential multiphoton absorption by compounds of a particular isotope leads to decomposition or reaction. [U(OMe)6] is used because the more obvious candidate UF, has insufficient absorption in the pulsed tunable C02 laser region of 9.2-10.8 pm (giving 10sW cm-').Irradiation at 927.04 cm-' just to the long- wavelength side of a combination (of U-0 A, and Tlu)band at 931 cm-' gave an enrichment of 1.0315 per pass where enrichment is 23sU/238U(final) 235U/238U(initial).A large range of uranates e.g. Ca,UO, BaUO, and BaU207 have been synthesized and characterized by i.r. and Raman spectroscopy and X-ray powder diffraction. Bond-stretching force constants are calculated and correlated with U-0 interatomic distance^.^^ Among a number of rather ordinary papers on uranyl complexes a few catch the eye. When [U02(N03)2(THF)2] is treated with NaOC(CF,) in ether-THF [U0~{OC(CF3)3}2(THF)2]is formed. On reaction between UO2CI2 and NaN(SiMe3)2 orange-red [U02{N(SiMe3)2}2(THF)2] is obtained., An n.m.r.study of [U02{OC(NMe2)2}5]2+ in CDCl and CD3CN solution has obtained parameters for the rotation of the NMez groups about the CN axes klg5 = 126 s-' AH* = 29 kJ mol-' and AS' = -52 J K-'mol-'. The dissociative ligand-exchange mechanism was also in~estigated.~~ The quenching of the luminescent state of uranyl nitrate by transition-metal (M) carbonyls has been investigated in acetone MeCN and THF. Flash photolysis e.s.r. and i.r. spectra show that quenching takes place with formation of [M(CO),]+ and U02'. The bimolecular quenching constants are related to the free energy of the electron-transfer process and hence to the oxidation 60 D. Brown and C. Hurtgen J.C.S. Dalton 1979 1709.61 G. W. Halstead P. G. Eller and M. P. Eastman Inorg. Chem. 1979,18,2867. 62 R. Bougon J. Fawcett J. H. Holloway and D. R. Russell J.C.S. Dalton 1979 1881. 63 P. J. Vergamini J.C.S. Chem. Comm. 1979 54. 64 S. S. Miller D. D. De Ford T. 3. Marks and E. Weitz J. Amer. Chem. SOC.,1979,101 1036. " G. C. Allen and A. J. Grifiths J.C.S. Dalton 1979 315. R. A. Andersen Znorg. Chem. 1979 18 209. 67 G. J. Honan S. F. Lincoln and E. H. Williams J.C.S. Dalton 1979 320. F. A. Hart P. Thornton,and J. Newbery potentials of [M(CO),]. The primary photoproducts irreversibly decompose to U4+ and M2+ions.68 Uranyl complexes with OP(OR) (R = Me or Et) are photoreduced to U'" via a U" intermediate which is stable in the dark but disproportionates in the light.69

ISSN:0260-1818    

DOI:10.1039/IC9797600121

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

F. A. Hart P. Thornton,and J. Newbery Part 11 Groups IVA VA and VIA By J. E. Newbery 1 Introduction This review of the early d-transition metals is necessarily selective and it attempts to cover the binary compounds and related systems and the co-ordination compounds of the metals. The topic of organometallic chemistry is not included except for a few examples that illustrate specific points. Reviews have appeared on a number of general topics of interest to these groups such as the analogy between metal clusters and surfaces,' and intramolecular organometallic species involving nitrogen donors.' More specific topics reviewed include the alkylidene complexes of niobium and tantal~m,~ and a brief account of fluoro-containing chromium(II1) c~mplexes.~ 2 Titanium Zirconium and Hafnium The elements of this group have again provided far fewer references than those of succeeding groups.d-d Spectra for titanium(I1) doped into a sodium chloride lattice have been ~bserved.~ The doping is claimed to produce isolated ions in an essentially octahedral site. TiO has been studied for its catalytic properties. In a flow system it has been found to be effective in promoting the photodecomposition of water.6 Other work has shown that a soup of ammonia water and methane In the presence of platinized TiOz will produce amino-acids when irradiated with light similar to that of the solar spectrum.' The novel titanium halides Ti7XI6 (X=C1 or Br) have been observed in the products obtained by heating TiC12 with A12C16 or Ti with Br2 and A12Br6 at 350 0C.8 The structure of the chlorine compound has been shown to contain octahedra of both Ti'" and Ti".Titanium tetraiodide exists in two crystalline forms;' the usual stable form is non-cubic and sparingly soluble in organic solvents whereas the metastable cubic from (X-ray determination) is soluble in hydrocarbon solvents. A new double S. Sostero 0.Traverso P. Di Bernardo and T. J. Kemp J.C.S. Dalton 1979,658. 69 G. Cauzzo G. Gennari G. Giacometti G. C. Agostini and A. Gambaro Inorg. Chim. Acta 1979,32,45. E. L. Muetterties T. N. Rhodin E. Band C. F. Brucker and W. R. Pretzer Chem. Rev. 1979,79,91. * I. Omae Chem. Rev. 1979,79,287. R. R.Schrock Accounts Chem. Res. 1979,12,98. J. W. Vaughn Synth. React. Inorg. Metal-Org.Chem. 1979,9 585. D. H. Brown A. Hunter and W. E. Smith J.C.S. Dalton 1979 79. H. Van Damme and W. K.Hall J. Amer. Chem. SOC.,1979,101,4373. 'H. Reiche and A. J. Bard J. Amer. Chem. SOC.,1979 101 3127. H. Schafer R. Laumanns B. Krebs and G. Henkel Angew. Chem. Internat. Edn. 1979,18 325. E. G. M. Tornqvist and W. F. Libby Inorg. Chem. 1979,18 1792. The Transition Elements 131 halide of formulation A3MF7 (A=Rb or Cs M=Ti or Cr) has been observed. Raman spectra indicate the presence of TiF6 structures." Ti2S3 has been studied by X-ray diffraction." It consists of a super-structure with complex phase behaviour. The ordering of the partially filled layers is discussed. A new method for the intercalation of transition metals into graphite has been reported,12 which uses a tetrahydrofuran solution of a metal salt in reaction with potassium graphite (CsK).Crystallographic analysis showed that the layer spacings were virtually independent of the metal. Zirconium hydrogen phosphate has also been used as host for inter~a1ation.l~ n-Alkanols and glycols have been incorporated directly and the resultant system then used to effect rapid intercalation of methyl cyanide or ethyl ethanoate which would otherwise take several days. The structure of zirconium phosphate gives it an ion-exchange capability. Ethyl- diethyl- and triethyl-ammonium ions appear to have 100°/~,50% and 25% respectively of the proton-exchange capacity. l4 Silver ions can also exchange" and the HP04'- ions from the interlayer surface can be reversibly exchanged by making a phosphoric ester.I6 A compound with a similar layer to the phosphate has been prepared." Zr(OPO,R) (R =n-butyl n-dodecyl or octylphenyl) has been tested as a support medium for the so-called 'reverse phase' liquid chromatography.Preliminary results indicate that it may have considerable advantages over more conventional systems. A study of some relevance to the complex-formation ability of Ti'" in aqueous solution has shown that hydrolysed polynuclear species such as [Ti80s(OH)12]4' exist even in 2.0 mol dm-3 hydrochloric acid.18 Turning to the co-ordination chemistry it is striking how little has been published on titanium. Octahedral complexes (1)have been studied by n.m.r. procedures to Me (1) X=HorCOMe investigate the fluxionality of titanium dike ton ate^.'^ The rate of degenerate enan- tiomerization has been compared with the rate of dionate methyl-site exchange.Free energy barriers of ca. 60 kJ mol-' are reported. I0 B. Hofmann and R. Hoppe 2.anorg. Chem. 1979,458 151. M. Onoda M. Saeki and I. Kawada 2.anorg. Chem. 1979,457 62. l2 D. Braga A. Ripamonti D. Savoia C. Trombini and A. Umani-Ronchi J.C.S. Dalton 1979 2026. l3 U. Costantino J.C.S. Dalton 1979 402. l4 J. P. Gupta and D. V. Nowell J.C.S. Dalton 1979 1178. I* M. G. Bernasconi M. Casciola U. Costantino and M. L. L. Giovagnotti Ann.Chim. (Italy)1979,69,9. l6 S. Yamanaka and M. Hattori Chem. Letters 1979 1073. l7 L. Maya Znorg. Nuclear Chem. Letters 1979,15 207. H. Einaga J.C.S.Dalton 1979 1917. N. Baggett D. S. P. Poolton and W. B. Jennings J.C.S. Dalton 1979 11 28. 132 F. A. Hart P. Thornton and J.Newbery Several reports concern eight-co-ordinate tetrakis-chelates of Zr and Hf. Since the relative energetic differences between different possible configurations are small these compounds tend to be non-rigid on the n.m.r. time-scale. However using the Freon solvent CHClF2 measurements have now been obtained” down to -170 “C and different stereoisomers of [M(Bu‘COCHCOMe),] [M(MeCOCHCOMe),] and [M(CF3COCHCOMe),] have been identified. Both ‘H and 19F resonances were employed leading to measurements of rate constants and a suggested mechanism for the exchange processes involved in intramolecular rearrangements.The structure of [Zr(PhCOCHCOPh),] has been determined by X-ray tech- niques.” The chelates occupy the s-edge of a distorted square antiprism (ssss-D2). Dodecahedra1 diketonate chelates of hafnium form the centre of an investigation of hyperfine quadrupole coupling constants.” The results were interpreted as giving support to the presence of T-bonding in such systems with the involvement of up to 20% of the overall charge donated by the ligands. The structure of the species Na4[Hf(0&H,),]21H20 sodium tetrakis(cate- cholato)hafnium has been rep~rted.’~ It is based on the dodecahedra1 configura- tion. When triacylmetalate dianions of the type [fac-(OC)3Re(MeCO)2(RCO)]’-(R =Me or Et) react with Zr’” or Hf’” the bis-chelates (2) are formed. These have isomeric forms when unsymmetric ligands are used.’ Me \c-0 ‘C-4 / hie (2) Infrared and Raman spectra form the basis of a study of the complexes [MCl4,2(S(CN),}] and [MC14Se(CN)2] (M =Ti or Zr).25 Analysis of the spectra supports the thio-compound as being S-bound with the trans-configuration for Ti and the cis-configuration for Zr.The selenium complex is assumed to have Se(CN)2 acting as a bidentate nitrogen donor species. Titanium(1v) in the less usual co-ordination of seven has been found by using the ligand RzNCSO-.26 The structures [M(LL),] were previously reported but use of a 3 :1 ratio in the preparation produces [Ti(R,NCSO),Cl] (R =Me Et Pr’ or Bu’). The crystal structure of the diethyl complex is reported and consists of a pentagonal bipyramid with the three co-ordinated sulphur atoms in cis-positions forming one triangular face.The chlorine is in the axial position (3). This co-ordination number is also found in the dithiobenzoate complexe~.~~ 2o R. C. Fay and J. K. Howie J. Amer. Chem SOC.,1979,101 11 15. *’ H. K. Chun W. L. Steffen and R. C. Fay Znorg. Chem. 1979 18 2458. 22 A. Baudry P. Boyer A. Tissier and P. Vulliet Znorg. Chem. 1979 18 3427. 23 S. R. Sofen S. R. Cooper and K. N. Raymond Znorg. Chem. 1979,18 1611. 24 D. T. Hobbs and C. M. Lukehart Znorg. Chem. 1979,18 1297. 25 M. S. Delgado and V. Fernadez Z. anorg. Chem. 1979 455 112. 26 S. L. Hawthorne and R. C. Fay J. Amer. Chem. Soc. 1979,101 5268. ” T. Roberie and J. Selbin I. Coordination Chem. 1979 9 89. The Transition Elem en ts The complexes of potassium tetrakis(pyrazo1- 1-yl)borate (4) with Zr have been reported.28 2 :1 Complexes ZrX,[B(pyz),] (X = C1 or Br) and 4 1 complexes Zr[B(pyz),] were isolated.The pyrazol-1-yl groups are assumed to act as bidentate ligands in the neutral species but n.m.r. evidence is claimed to support possible terdentate behaviour in the 2 1chloride complex. There are no reports involving macrocyclic ligands the nearest approach being a Schiff-base complex (5) of zirconium,29 produced as shown. The structure indicates a dodecahedra1 framework around Zr with the nitrogen atoms in the A positions and the oxygen atoms in the B positions. The chelate ligands span the mum edges. -t-Zr Spectral data for a large number of titanium Schiff-base (SB) complexes indicate two main classes [X2Ti(SB)] and [Ti(SB),] (X = OMe OEt or OPr').The SB ligands are terdentate (ON0 or ONS) and the alkoxide species attain the favoured six- co-ordinate state by dimeri~ing.~' The structure is reported of the Zr and Hf analogues of the previously known titanium complex [{(Me2N)2M(B~fN)}2] which have the two Bu'N groups bridging the metal atoms to given an approximately tetrahedral c~nfiguration.~~ The bis- trimethylsilylamine products [M{N(SiMe,),},Cl] and [M{N(SiMe3)2}2C1z] have been isolated.32 The heterodifunctional ligand (6) has been synthesized and attached to two different metals., This is claimed to be unique. A number of zirconium species are included in this report [e.g.(7)]. 28 S. Asslani R. Rahbarnoohi and B. L. Wilson Znorg. Nuclear Chem. Letters 1979 15 59. 29 R. D. Archer R. 0.Day and M. L. Illingsworth Znorg. Chem. 1979,18,2908. 30 E. C. Alyea A. Malek and P. H. Merrell Transition Metal Chem. 1979 4 172. 31 W. A. Nugent and R. L. Harlow Znorg. Chem. 1979,18,2030. 32 (a)R. A. Anderson Inorg. Chem. 1979 18 1724; (b)R. A. Anderson ibid. p. 2928. 33 N.E. Schore J. Amer. Chem. SOC.,1979,101 7410. F. A. Hart P. Thornton and J. Newbery Me CI' \ 3 Vanadium Niobium and Tantalum Co-precipitation of vanadium and magnesium hydroxides produces a system able to reduce ethyne to ethene and ethane and dinitrogen to hydrazine or ammonia.34 The dependence of yields and rates upon V" concentration is explained by invoking the presence of V" clusters on the surface of the magnesium hydroxide.Lanthanide vanadates [Na3Ln(V04)2] have been found to have two allotropic forms. The structure of the neodymium salt has been determined and appears to be related to @-K2S04with silated V04 tetrahedra.35 Vanadates of Group I metals have VO bending modes in the region 330-390 cm-' and VOV bending modes in the range 210-280cm-'. A linear relationship was also observed between the cation translational frequency and mass- suggesting a similar value for the various translational force constants.36 Na,V,07(H20)l has been found to have [V,O7]"- units situated in cavities built up from infinite chains of Na(H20)6 Two separate orientations were detected. Crystals of K6Ta3(02)30F13H20 have been prepared from and the structure is based on [Ta(O,)F5l2- units with an 0x0-bridge (8).F Two reports have appeared on binary taiitalum halides. TaF5 has been shown by electron diffraction to exist in a trimeric form at ca. 45°C.39 This confirms mass spectral assignmcnts and contrasts with higher-temperature reports of a tetramer. TaCl melts have been observed by Raman methods and the existence of several different species (dependent on temperature) is indi~ated.~' 34 N. T. Denisov A. G. Ovcharenko V. G. Svirin A. E. Shilov and N. I. Shuvalova Nouueau J. Chim. 1979 3,403. 35 C. Parent J. Fava R. Salmon M. Vlasse G. LeFlem P. Hagenmuller E. Antic-Fidancev M. Lemaitre-Blake and P. Caro Nouueau J. Chim. 1979 3 523. 36 S. Onodera and Y.Ikegami Inorg.Chem. 1979,18,466. 37 A. Bjornberg Acra Chem. Scand. 1979 A33 539. 38 W. Massa 2. anorg. Chem. 1979 456 169. 39 J. Brunvoll A. A. Ischenko I. N. Miakshin G. V. Romanov V. B. Sokolov V. P. Spiridonov and T. G. Strand Acra Chem. Scand.. 1979 A33,775. 40 R. Huglen F. W. Poulsen G. Mamantov and G. M. Begun Inorg. Chem. 1979,18,2551. The Transition Elements 135 The halide clusters [M6ClI2]"+ (M=Nb or Ta) have been studied by X-ray photoelectron ~pectra,~' which suggest the presence of different halide environ- ments. [K4{Nb(CN)8}2]H20 has a dodecahedra1 structure rather than the expected square an ti-prism .42 The formation constants of 1 1complexes of a number of aminocarboxylates with vanadium(v) have been measured spectrophotometrically.43 Evidence was obtained for some 1:2 complexes and various protonated 1 1species.Heating an oxovanadium(1v) bis-chelate with either SO in benzene or PCI5 in dioxan produces a simple deoxygenation reaction to give the corresponding halide (9).44The product is in the all-trans configuration (Cl/Cl; O/O; N/N). LL =pentane-2,4-dionato or oxine. (9) Magnetic susceptibility data suggest that a series of oxovanadium(1v) complexes with Schiff's bases formed from a series of salicylaldehyde species are mostly probably dime~ic.~' The reactions of vanadium(v) with hydroxylamine and N-methylhydroxylamine have been re-in~estigated.~~ A number of complexes that have previously been formulated as hydroxylamine complexes are shown to be nitrosyls e.g.[V(terpy)(H2NO)(NO)(H20)]Br. No production of N2 N20 or NH3 was observed. The structure and e.s.r. spectra have been determined4' for a mixed-valence dinuclear vanadium complex [VO(nta)-O-VO(nta)]'- (nta = nitrilotriacetate) formed as deep blue crystals by mixing [V"'O(nta)H20]- with [VVO2(nta)l2-. The e.s.r. spectra indicate delocalization of an electron in solution and the X-ray study shows approximate octahedral symmetry about the vanadiums with a linear VOV system. The two centres are equivalent in both the solid and solution phases. A more complex bridging system is formed by pyrazine [(10); pyz] or diazabicyclo- octane [(ll); dabco]. These have been used to bridge (B) the vanadyl complexes of (10)PYZ (1 1) dabco trifluoropentane- 1,5-di0ne,~~ forming [{VO(tfp),},B].The pyrazine (and substituted pyrazines) species showed maxima in the susceptibility/temperature curves at temperatures varying (with species) from 7.0 to 3 1.5 K. None of the systems studied 41 S. A. Best & R. A. Walton Inorg. Chem. 1979 18 484. 42 M. Laing G. Gafner W. P. Griffith and P. Kiernan Inorg. Chim. Acm 1979 33 L119. 43 K. Zare P. Lagrange and J. Lagrange J.C.S.Dalton 1979 1372. 44 M. Pasquali F. Marchetti and C. Floriani Inorg. Chem. 1979 18 2401. A. Syamal and K. S. Kale Inorg. Chem. 1979 18 992. K. Wieghardt and U. Quilitzsch Z. anorg. Chem. 1979 457 75. 47 M. Nishizawa K. Hirotsu S. Ooi and K. Saito J.C.S. Chem. Comm. 1979,707. 48 M. S. Haddad D. N. Hendrickson J. P. Cannady R. S.Drago and D. S. Bieksza J. Amer. Chem. SOC. 1979,101,898. 136 F. A. Hart P. Thornton and J. Newbery was considered to be efficient at promoting exchange interactions via a 0-type pathway . RSe02Na is reported to react with VCl to produce [V(02SeR)3] (R = Me or Ph).49 [{(Me3Si),N},TaR3] has been prepared.” A multiply bonded alkylimido-complex of vanadium(v) has been reported for the first time.” The tetrahedral complex (12) (R = But or 1-adamantyl) was obtained as shown. Me3Si0 Bu‘NH(SiMe3) \J N/SiMe rearrangement (Me,SiO),V=NR -b The VNR grouping is nearly linear (175.8’) and the V-N bond 161.4 pm long in the 1-adamantyl complex suggesting considerable triple-bond character. The first phosphiniminato-vanadium complexes are formulated [VOC12(NPPh3)] [VOCl(NPPh,),] and [VC13(NPPh3)2].52 The complexing of various azole species has also been rep~rted.’~ Structural data are available for various niobium porphyrin species,54 Seven-co-ordination is observed for [{Nb(L)}203],4(C2H4C12),and [Nb(L)O(O,CMe)],MeCO,H (where L is the dianion of 5,10,15,20-tetraphenyl-porphyrin).In both examples the niobium atom lies about 100 pm from the plane of the nitrogen atoms. These data are supported by high-resolution n.m.r. studies. 4 Chromium Molybdenum and Tungsten The Group VIA elements have been studied in far greater depth than those of the preceding two groups. For greater clarity the references are divided up into two basic groups (a)the chlorides oxides and sulphides including some metallic clusters and (b) the co-ordination chemistry involving ligand species although the categorization is by no means perfect.Simple Species.-Halides. The new double salt A3MF7 (M = Ti or Cr) was mentioned under titanium.” The structures of the complex ion species [Mo(0)X4H20]- have been reported for X = C1 and BT.’~ The chloro-species has approximately octahedral symmetry with the halides in the equatorial position. The ion [MO~C~&]~- has been studied with two different cations,” and has two bridging chloro-atoms a bridging hydrogen atom and a Mo-Mo distance of ca. 237 pm. [W2ClSSe3]*- containss6 a bridging Se2 group (13) with W-W as 286 pm and thus probably a single bond. 49 I.-P. Lorenz Inorg. Nuclear Chem. Letters 1979 15 127. 5o R. A.Anderson Inorg. Chem. 1979 18 3622. ” W. A. Nugent and R. L. Harlow J.C.S. Chem. Cornm. 1979,342. 52 R. Choukroun D. Gervais and J. R. Dilworth Transit. Metal Chem. 1979 4 249. 53 Z. Karwecka J. Coordination Chem. 1979 9 37. 54 C. Lecomte J. Protas R. Guilard B. Fliniaux and P. Fournari J.C.S. Dalton 1979 1306. 55 A. Bin0 and F. A. Cotton (a)J. Amer. Chem. SOC. 1979,101,4150; (b)Inorg. Chem. 1979,18,2710; (c)Angew. Chem. Internat. Edn. 1979 18 332. 56 M. G. B. Drew G. W. A. Fowles E. M. Page and D. A. Rice J. Amer. Chem. Soc. 1979,101,5527. 137 The Transition Elements Solution work has included an extended X-ray absorption fine-structure (EXAFS) study of Mo'" in 4M-HC1.57 The data are claimed to be compatible with a dioxo- bridged dinuclear species that does not include any chloro-co-ordination.A short account of the methodology of EXAFS and its application to the study of bio- inorganic species has appeared." Oxides. The compound NaM0406 has been synthesized from the product of a sealed-tube reaction at 1100"C between Na2MoO4 Mooz and ZnO (ratio 1:5 :2). The structure consists of linear chains made from clusters of Mo6OI2 composition with the sodium ions occupying sites in channels formed between four The photogalvanic effect has been studied in the compound (PT~NH~)~(Mo~O~~). 3H20.60 A blue complex isolated from a photoreduced solution of this substance has been shown by X-ray work to contain Keggin-type structures of formulation [Mo13040]4- and [H4Mo 2040]4-.61 Isopolytungstates and heteropolytungstates have been studied by lS3W n.m.r.spectroscopy for the first time.62 Sharp lines ( WlI2< 1Hz) were found in DzO solutions and the chemical shifts produced were markedly dependent upon the heteroatom and the stereochemical environment. The structure of what is claimed to be the largest isopolyanion yet analysed has been K~[Mo360112(H~0)~~],36H~0 consists of two 18-molybdate sub-units which combine via four common oxygen atoms to form a ring that accommodates some cations and also water of crystallization. (NH4)7[H2A~W18060],16H20 consists of two Xw9033 sharing six common oxygens. One unit contains on the interior X = AS'" with its lone pair directed towards the second unit which has X = 2H. As a consequence of their interior position these protons cannot be titrated.A number of publications have reported the attachment of organo-species to heteropoly anions. [XW11(MR)039](n-3)- and [X2W17(MR)061]7- (X = R or As M = Ge Sn or Pb) have been described6' as having an extensive redox chemistry. Reaction of RSnC13 RSiC13 RGeC13 RAsCl, or [CsH5TiC13] with 1l-heteropoly-anions such as [Wl1SiO3,]" [WllP039]7- or [Mo11Si039]8- leads to the attachment of RM.66 N.m.r. spectra indicate three main binding modes. More complex formu- lations such as [(T-C5H5)Fe(C0)zGe]z[WllSi040]4-have also been An " S. P. Cramer H. B. Gray Z. Dori and A. Bino. J. Amer. Chem Soc. 1979 101 2770. '* S. P. Cramer and K. 0.Hodgson Progr. Inorg. Chem. 1979,25 1. 59 C. C. Torardi and R. E. McCarley J. Amer.Chem. SOC., 1979,101 3963. 6o T. Yamase and T. Ikawa Znorg. Chim. Am. 1979,37 L529. " T. Yamase T. Ikawa Y. Ohashi and Y. Sasada J.C.S. Chem. Comm. 1979,697. '* R. Acerete C. F. Hammer and L. C. W. Baker J. Amer. Chem. SOC., 1979,101 267. 63 I. Paulat-Boschen J.C.S. Chem. Comm. 1979 780. 64 Y. Jeannin and J. Martin-Frkre Znorg. Chem. 1979 18 3010. 65 F. Zonnevijlle and M. F. Pope J. Amer. Chem. SOC.,1979 101 2731. 66 W. H. Knoth J. Arner. Chem. SOC.,1979 101 759. 67 W. H. Knoth J. Amer. Chem. SOC.,1979 101 2211. F. A. Hart P.Thornton and J. Newbery X-ray study of another organo-species formed by the action of formic acid on the [Mo7024]6-ion has shown the presence of a unique octamolybdate cluster [(HCO)2M08028]6-containing unidentate co-ordinated formyl groups.68 The anion [(CH,)MO,O,,H]~-has four coplanar molybdenum atoms and is held together by four doubly bridging oxygens two triply bridging oxygens and a bridging hydr~xyl.~'The CH2group is bound to the two triply bridging species.Sulphides. (NH4)4[Mo4(NO)4S13],2H20 is produced from the reaction of molybdate ions with ammonium poly~ulphide.~~ The structure (14) contains two triply bound 0 N and one quadruply bound sulphur atom. Four of the S22-ligands are bound by both atoms to one molybdenum and also act via one atom only as a bridging group. A less complex structure [Mo"~O~S~(S~)~]~-is formed from [MoV1O2S2]'-by an intramolecular redox proces~,~' producing a structure with bridging S groups and a p-S22-group bound to each molybdenum.A similar process produces [W30S8H20]2-from [WS4I2-ions.72 This has a linear structure with bridging sulphur atoms and the central tungsten bearing both the oxygen and the water in a trans configuration. n-Type MoS dissolved in methyl cyanide has beer investigated by cyclic voltam- rnetr~.~' It was found that the band-gap is such that the uphill oxidation of C1- can be photo-oxidized under these conditions. The species [M' (M2S4),I2-(M1 = Ni" Pd" or Pt" M2= Mo or W) have also been studied by cyclic ~oltarnmetry.~~ Indications were obtained for species with formal oxidation states of 1and 0 for Ni and Pd and 0 for Pt. Co-ordination Compounds.-Trigonally symmetric d * systems (Cr03-) have been analysed and the g-factor anisotropy values calculated for different ligand-field 68 R.D. Adams W. G. Klemperer and R.-S. Liu J.C.S. Chem. Comm. 1979,256. 69 V.W. Day M. F. Fredrich W. G. Klemperer and R.4. Liu J. Amer. Chem. SOC. 1979,101,491. 'O A. Miiller W. Eltzner and N. Mohan Angew. Chem. Znternat. Edn. 1979 18 168. 71 W. Rittner A. Miiller A. Neumann W. Bather and R. C. Sharma Angew. Chem. Znternat. Edn. 1979 18 530. 72 A. Miiller R. G. Bhattacharyya E. Konigerahlborn R. C. Sharms W. Rittner A. Neumann G. Henkel and B. Krebs Inorg. Chim. Actu 1979 37 L493. " L. F. Schneemeyer and M. S. Wrighton J. Amer. Chem. SOC. 1979,101,6496. 74 K. P. Callahan and P. A. Piliero J.C.S. Chem. Comm. 1979 13. The Transition Elements parameter^.^' A rationale of spectrochemical results for the halide complexes of Cr"' has been made by extended Huckel calculation^.^^ It is suggested that whereas the stabilization energy of the bonding eg orbitals in [CrF6I3- is less than that in [CrCl6I3- the reverse is true for the antibonding orbitals thus giving F-the appearance of being a better donor than C1-.Mononuclear Complexes. The structure and absolute configuration of (-)-tris(pentane-2,4-dionato)chromium(111) have been defe~mined.~~Photo-redox behaviour of Crr*' has been in~estigated.~~'~~ The failure of the former study to detect such a tendency has been ascribed79 to the use of poor proton donor solvents that are unable to stabilize the photogenerated ligand radical from the species trans-tris-( l,l l-trifluoropentane-2,4-dionato)chromium(111).Investigations" of the cisltrans pair of tris(benzohydroxamoto)chromium(III) have shown that the cis-complex is almost regular octahedral whereas the trans-complex which may be of some use as a model compound for rhodoturulic acid is trigonally distorted. A four-member series of compounds [CrL,]"- (n =0-3 L =3,5-di-t-butyl-o- benzoquionone) has been prepared and studied by X-ray Lr. and e.p.r. methods." The production of a stable water-soluble chromium(v) complex has been described.82 Na[OCr(02COCR'R2),] is formed by the reaction in acetone of a tertiary a-hydroxy-carboxylic acid R'R2C(OH)C02H with anhydrous sodium dichromate. The product is soluble in water and acetone and in the presence of crown ethers dissolves in hydrocarbons as well.A series of cis/ trans pairs of bis(trimethylenediamine)chromium(III) complexes with SCN- NO; N; HzO etc. has been prepared.83 Structural comparisons are made and the absolute configurations of a number of the complexes assigned. A series of chromium(I1) complexes with substituted pyridines such as [Cr(py)2ha12] [Cr(~y)~(H~0)~1~] or [Cr(py)J,] has been characterized by i.r. and magnetic Possible five-co-ordinate chromium(I1) is reported for a number of pyrazole species8' The structure of the first metal-thiohydroximate complex to be studied shows that the ligand (15) is co-ordinated in the cis-configuration in the complex ion " L. G. Vanquickenborne C. Gorller-Walrand and R. Debuyst J.C.S.Dalton 1979 1150. 76 J. K. Burdett J. Amer.Chem. SOC.,1979 101 580. 7f R. Kuroda and S. F. Mason J.C.S. Dalton 1979 273. 78 E. Zinato P. Riccieri and P. S. Sheridan Znorg. Chem. 1979,18 720. 79 G. Ferraudi D. B. Yang and C. Kutal J.C.S. Chem. Comm. 1979 1050. K. Abu-Dari J. D. Ekstrand D. P. Freyberg and K. N. Raymond Znorg. Chem. 1979,18,108. S. R. Sofen D. C. Ware S. R. Cooper and K. N. Raymond Inorg. Chem. 1979,18,234. 82 M. Krumpolc and J. RoEek J. Amer. Chem. SOC.,1979 101 3206. 83 N. Nakano and S. Kawaguchi Bull. Chem. SOC.Japan 1979,52,3563. M. M. Khamar L. F. Larkworthy and D. J. Phillips Inorg. Chim. Acta 1979 36 223 F. Mani and R. Morassi Znorg. Chim. Acta 1979 36 63. F. A. Hart P. Thornton and J.Newbery [Cr{PhC(S)N(0)}3]3-."6 The same study also produced evidence for the first discrete H3O2- anion with a structure similar to that of the isoelectronic HF2-.Chromium(II1) forms two types of complex (17) with the ligand (16) thio-bis(ethylenenitri1o)tetra-acetic acid." These species differ as to the geometry of the nitrogen attachment and as to whether the sulphur atom is co-ordinated. OH OH ,CH2C02H 'CH2C02H pH1.25"C S (16) cis-form (violet) trans-form (pink) 0' (17) Comparisons of X-ray data for a series of complexes [Cr(CO),(XPh3)] (X = P As Sb or Bi) show significant variations in the CXC and CrXC bond angles."" The trend is interpreted as showing increased s-character from X = P to X = Bi as opposed to dr-dv bonding which should (from an energy/size viewpoint) be maximized at X=P. Virtually all the complex chemistry reported for mononuclear molybdenum concerns the oxomolybdenum(v1) species.The "0 n.m.r. linewidth and para- magnetic chemical shifts have been measured for a variety of such complexes and the results correlated against known force constants and bond lengths of the Mo-0 bond.89 [MoV'(Cys)H;02)] (Cys =cysteine) is the end product from the disproportionation of [MO~,(C~S)~] in pH 6.5 buffer in the presence of oxygen.9o Structural data for [MoO,X,(PP~~O)~] = C1 or Br) indicate that the species have (X distorted octahedral struct~res.~~ Both the oxygens and the phosphine oxides are cis to one another and mutually trans and the halogen ligands are trans to one another. It is suggested that in these mixed-ligand species the weaker T-bonding ligand will occupy positions trans to the terminal oxygens and hence avoid competition for the available empty metal 4d-orbitals.Reaction of [MoO4I2- with hydroxylamine in the presence of bipyridyl or terpyridyl a seven-co-ordinate MoIV ion formulated as [Mo(bipy)(H,NO),NO]-or [Mo(terpy)(H2NO)(N0)(H2O)]*+. The structure has been determined for the bipyridyl case. Use of a substituted (weaker reducing agent) hydroxylamine allows co-ordination to take place without the formation of Mo'~ producing [MoO,(M~HNO)~]. This has been shown to have cis-0x0-groups and NO-bonded hydroxylamine. 86 K. Abu-Dari D. P. Freyberg and K. N. Raymond Znorg. Chem. 1979,18,2427. " P. J. Peerce H. B. Gray and F. C. Anson Inorg. Chem. 1979 18 2593. 88 A. J. Carty N.J. Taylor A. W. Coleman and M. F. Lappert J.C.S. Chem. Comm. 1979 639. 89 K. F. Miller and R. A. D. Wentworth Znorg. Chem. 1979 18,984. 90 T. M. Tam and J. H. Swinehart Znorg. Chem. 1979,18,975. 91 R. J. Butcher B. R. Penfold and E. Sinn J.C.S. Dalton 1979 668. 92 (a)K. Wieghardt W. Holzbach J. Weiss B. Nuber and B. Prikner Angew. Chem. Internat. Edn. 1979 18 548; (6)K. Wieghardt and W. Holzbach ibid. p. 549. The Transition Elements 141 The structure of [MOC~(N,COP~)(NHNCOP~)(PM~~P~)~] has been molybdenum has octahedral co-ordination with two crystallographically distinct molecules. [Mo(NNMe2)0(S2CNMe2),] is also ~ctahedral~~ and the bond lengths and angles indicate a structure where (18a) rather than (18b) predominates. Substi- tuted hydrazines (RCONHNHPh) form ionic species with m~lybdenurn.~' The cation of [MoCl(O)(Ph2PCH2CH2PPh2)2]~[MoC130(p-C1C6H4CONNPh)]~ is a previously studied structure and the anion is approximately octahedral with the chlorides in a mer-configuration.M~N-N AR* 'R2 (1 84 (18b) Cyclic voltammetry and e.s.r. methods were used to study redox processes in a series of complexes [Mo(N,R)(S,CNM~~)~].'~ The structures of [Mo(N,Ph)-(S2CNMe2)3] [Mo(NPh),(S2CNEt~),l [Mo(NS)(SKNMe2)31 and [MoN(S2CNEt,),] have been A number of complexes [M(N2)2(PR3)41 [MX2("H2)(PRd31 and [MX,NHNH,(PR3)31' (M = W or Mo X = C1 or Br) have been prepared.loO Acid hydroysis produces hydrazine as well as ammonia. Dithiobenzoates of MoIV are reported. lo' The compound [MoO(S3CPh)(q3-S2CPh)] has a bidendate S3CPh group and both sulphurs and the carbon (Mo-C = 221.7 pm) are co-ordinated from the S2CPh group.lo2 X-Ray photoelectron spectroscopy has been applied to tripod sulphur complexes of MeV' and is able to distinguish thiol and thio ether modes of attachment within the same molecule.O3 The synthesis of what is claimed as the first pair of monomeric molybdenum-(v) and -(vI)species with a common ligand has been achievedlo4 with 8-mer-captoquinoline. Oxochlorobis-(8-mercaptoquinolinato)molybdenum(v)has been shown to have the chlorine atom cis to the 0x0-group rather than the expected trans orientation. This shape is retained in the dioxomolybdenum(v1) complex. The MoIV complex [MoO(SCH~CH~PP~,)~] has been found to be five-co-ordinate (intermediate between trigonal-bipyramidal and square-pyramidal).lo' The thio- nitrosyl complex [Mo(NS)(S,CNMe,),] was obtained in low yield by refluxing [Mo02(S2CNMe2),] with SiMe3(N3) in acetonifrile.lo6 Reaction of a nitrido-complex [MoN(S,CNR,),] with elemental sulphur produces the same substance in 93 A. V. Butcher J. Chatt J. R. Dilworth G. J. Leigh M. B. Hursthouse S. Amarasiri A. Jayaweera and A. Quick J.C.S. Dalton 1979 921. 94 M. W. Bishop J. Chatt J. R.Dilworth M. B. Hursthouse and M. Motevalli J. C.S.Dalton 1979,1600. 95 M. W. Bishop J. Chatt J. R. Dilworth M. B. Hursthouse and M. Motevalli J.C.S. Dalton 1979 1603. 96 G. Butler J. Chatt G. J. Leigh and C. J. Pickett J.C.S. Dalton 1979 113. 97 M. W. Bishop G. Butler J. Chatt J.R. Dilworth and G. J. Leigh J.C.S. Dalton 1979 1843. 98 B. L. Haymore E. A. Maatta and R. A. D. Wentworth J. Amer. Chem. SOC.,1979,101 2063. 99 M. B. Hursthouse and M. Motevalli J.C.S. Dalton 1979 1362. loo T. Takahashi Y. Mizobe M. Sato Y.Uchida and M. Hidai J. Amer. Chem. SOC.,1979,101 3405. lo' T. Roberie A. E. Hoberman and J. Selbin J. Coordination Chem. 1979 9 79. lo' M. Tatsumisago G. Natsubayashi T. Tanaka S. Nishigaki and K. Nakatsu Chem. Letters 1979 889. lo3 V. Srinivasan E. I. Stiefel A. Elsberry and R. A. Walton J. Amer. Chem. SOC.1979 101 2611. K. Yamanouchi and J. H. Enemark Inorg. Chem. 1979,18 1626. lo' J. Chatt J. R.Dilworth J. A. Schmutz and J. A. Zubieta J.C.S. Dalton 1979 1595. '06 M. W. Bishop J. Chatt and J. R. Dilworth J.C.S. Dalton 1979 1.F. A. Hart P. Thornton and J. Newbery much higher yields. The system is fluxional on the n.m.r. time-scale and has an MoNS bond angle of 172". A new route for the preparation of [MoOS~(S~CNR~)~] complexes and the relevance to the lability of the reactive sulphur in molybdo- enzymes are reported."' Relatively few mononuclear tungsten complexes have been reported. The zero- valent [W{P(OMe)3}6] has been synthesized and shown to have an interesting photo- chemistry.lo8 A series of mixed-ligand complexes involving hard intermediate and soft donors has been prepared,'" with formulae [W(CO),(PP~,)(~C~)~] [W(CO),( PPh3)( dcq)Cl] and [W(CO),( PPh3),(dcq)C1] (dcq = 5,7 -dichloro-8-quinolinato). The physical and chemical behaviour is consistent with seven-co- ordinate species.Mononuclear Macrocyclic Complexes. The N4 macrocycle [ 15]ane-N (19) reacts with Cr" chloride to produce the strongly reducing complex [Cr"( 15[ane]-N4)I2' which in the presence of RCl produces the Cr"' pans-species [RCr(lS[ane]- N4)H20I2+.'loThe kinetics of the processes are discussed. Resonance Raman spectra are reported for various oxomolybdenum(v) tetrapyrrole species."' HnH c ",, HWH (19) [ 1SIane-N The process [M(Pp)OH,] $ [M(Pp)OH]+ H' [where Pp is a porphyrin ring and M a transition-metal(II1) ion] has been discussed from a ligand-field viewpoint.' l2 Trends in the binding constants can be explained via the tetragonal electrostatic field for Cr Mn Fe Co and Rh. The generation and characterization of a stable oxoporphinatochromium(v) complex capable of sustaining oxygen transfer has been discu~sed."~ It can be used to catalyse hydroxylation and epoxidation of alkenes and may have some relevance to the cytochrome P-450 cycle for iron species.A similar compound for tungsten has the added advantage of being water-soluble; 5,10,15,20-tetra-(p-sulphonato-phenyl)porphinatotungstyl(v) methoxide undergoes oxidative demetallation via oxidation of the co-ordinated metal by molecular oxygen.' l4 [Mo(C12)(tetra-p-tolylporphyrin)] is a non-0x0-molybdenum(1v) species.11s Reduction by zinc amalgam under NO eventually produces two mitrosyl species lo' K. Leonard K. Plute R. C. Haitiwanger and M. R. DuBois Znorg. Chem. 1979 18 3246. lo* H. W. Choi R. M. Gavin and E.L. Muetterties J.C.S. Chem. Comm. 1979 1085. W. H. Batschelet R. D. Archer and D. R. Whitcomb Znorg. Chem. 1979 18 48. G. J. Samuels and J. H. Espenson Znorg. Chem. 1979,18,2587. 'I1 N. Ohta W. Schevermann K. Nakamoto Y. Matsuda S. Yamada and Y. Murakami Znorg. Chem. 1979 18,457. 'I2 G. McLendon and M. Bailey Znorg. Chem. 1979 18 2120. J. T. Groves and W. J. Kruper jun. J. Amer. Chem. SOC.,1979 101 7613. E. B. Fleischer R. D. Chapman and M. Krishnamurthy Znorg. Chem. 1979 18 2156. 'I5 T. Diebold B. Chewier and R. Weiss Znorg. Chem. 1979. 18 1193. The Transition Elements [MO(ttp)(NO)2(C6H6)]and [Mo(ttp)(No)(MeoH),2c6H6].' l6 The dinitrosyl species has the two NO groups on the same side of the porphyrin ring slightly bent towards each other whereas the second species has NO and MeOH in trans positions.cis-Dioxomolybdenum(ttp) results from the photolysis of bis(peroxo)molybdenum- (ttp)."' [W=O(OH)tetraphenylporphyrin] has been synthesized and its e.p.r. and i.r. spectra have been recorded.lI8 Bridged Complexes. A single report of an authenticated mono-bridged molybdenum species concerns [MO~(CN)~~S]~-."~ The structure is based on seven-co-ordinate pentagonal-bipyramidal symmetry about the molybdenums with the bridging sulphur in the axial position. The MoSMo angle is 169.5'. The bridging bond is relatively short (217.3 pm) and is resistant to hydrolysis. Diethyldithiocarbamates (20) of molybdenum(v) have been X-rayed in a number of complexes. [MO~O~(S~CNE~~)~] is roughly octahedral about the molybdenums with oxo-bridging,12' whereas [MO~O~S~(S~CNE~~)~] has sulphur bridges.12' These Et2NC< /rs-S (20) species also promote the dehydrogenation of hydrazobenzene to azobenzene and the oxygenation of triphenylphosphine whereas 00and ON chelates are ineffective.'22 Structures of di-F.- hydroxochromium complexes of formulation [Cr2(OH)2(en)4]X4,2H20 (X = C1 or Br) have been determined as part of a wider series of complexes [X = I or X = C12(C104)2] used to investigate exchange inter- action~.~~~ A slight temperature dependence of the exchange parameter J was observed. Triple mixed sulphur-oxygen bridges have been found in the ion [Mo203(SCH2CH20),]'- which has one (SCH2CH20) group and one 0x0 in a bridging and in [Mo,O,(SR)~~]- where Z may be OR SR or NR2.125 These species have a triple bridge involving two of the SR groups and the Z group.Highly air-sensitive tetraphenylarsonium salts of the anion (2 1)have been pre- pared by reaction of the potassium salt C4S4K2(H20) with [M(C0)6] (M =Cr Mo or W) in diglyme.lZ6 (21) '16 T. Diebold M. Schappacher B. Chewier and R. Weiss J.C.S. Chem. Comm. 1979 693. H. Ledon M. Bonnet and J.-Y. Lallemand J.C.S. Chem. Comm. 1979 702. M. Krishnamurthy Znorg. Chim. Acta 1979 32 L32. '19 M. G. B. Drew P. C. H. Mitchell and C. F. Pygall J.C.S. Dalton 1979 1213. 120 C. D. Garner N. C. Howlader F. E. Mabbs A. T. McPhail and K. D. Onan J.C.S. Dalton 1979,962. 12' A. Muller R. G. Bhattacharyya N. Mohan and B. Pfefferkorn Z.anorg. Chem. 1979,454 118. 12' A. Nakamura M. Nakayama K. Sugihashi and S. Otsuka Znorg. Chem. 1979 18 394. 123 A. Beutler H. U. Gudel T. R. Snellgrove G. Chapuis and K. J. Schenk J.C.S. Dalton 1979 983. 124 1. G. Dance and A. E. Landers Znorg. Chem. 1979,18,3487. 125 I. W. Boyd I. G. Dance A. E. Landers and A. G. Wedd Znorg. Chem. 1979,18 1875. 126 F. Gotzfried W. Beck A. Led and A. Sebald Angew. Chem. Znternat. Edn. 1979,18,463. 144 F. A. Hart P. Thornton and J. Newbery Complexes [{(CsHs)Mo(SC,H2nS)}2](n= 2 or 3) are formed from reaction of alkyl sulphides with [{(C5H5)Mo(C0)3}2].'27 Cyclic voltammetry shows two reversible oxidation steps and products from both stages have been isolated. The monocation shows bridging by the dithiolate species with the four sulphur atoms forming a plane bisecting the Mo-Mo distance.Reaction of [{(C5H5)Mo(SC,H4S)},] with ethyne produces ethene and [{(CsH5)Mo(SCzHzS)},] which in turn may be reduced back by hydrogen. Crystal-field parameters have been evaluated from the electronic spectra of a number of trinuclear Cr'" complexes with chloro- and dichloro-ethanoic acids.'28 Cluster Compounds. Na4[Mo608(edta)3]14Hz0 consists of two equivalent trinuclear units composed of three molybdenum atoms in an equilateral triangle (side 25 1pm) with one triply bridging and three ordinary bridging oxygens."' The edta fragments bridge between the trinuclear units. Previously reported Mo-edta species were mainly simple dinuclear structures. A series of Mo-Fe-S clusters (22)-(24) all contain two basic cubane structures of [Fe3MoS4] linked together by a variety of bridging mode^.'^^.'^' Mossbauer data on EtS Et SEt EtS / SEt \ Et EtS/ SEt Et EtS SEt Et Et / Fe-S -~~ Et Et SEt EtS/ \ (24) the iron indicate a similar oxidation state to that found in the Fe-Mo cofactor of nitrogenase compound (22) by the EXAFS criterion most closely resembling the molybdenum environment in the enzyme.The tungsten analogue of (22) has the same unsymmetric bridging,'32 also found in [MO~F~~S~(SCH,CH~~H)~]~-, which is water-s~luble.'~~ also consists of two cubane structures [W2Fe6S8(SPh)6(0Me)3]3-but with symmetric triple meth~xo-bridges.'~~ The species [(Mo,S,A~,)(PP~~)~] 12' M. R. DuBois R. C. Haltiwanger D.J. Miller and G. Glatzmaier J. Amer. Chem. SOC. 1979,101,5245. M. Makles-Grotowska and W. Wojciechowski Bull. Acad. polon. Sci. Skr. Sci. chem. 1979 21 59. 129 A. Bino F. A. Cotton and Z. Dori J. Amer. Chem. SOC.,1979 101 3842. lJo T. E. Wolff J. M. Berg K. 0.Hodgson R. B. Frankel and R. H. Holm J. Amer. Chem. SOC. 1979,101 4140. 13' T. E. Wolff J. M. Berg P. P. Power K. 0.Hodgson R. H. golm and R. B. Frankel J. Amer. Chem. SOC. 1979,101,5454. 13* G. Christou C. D. Garner R. M. Miller and T. J. King J. Inorg. Biochem. 1979 11 349. 133 G,Christou C. D. Garner F. E. Mabbs and M. G. B. Drew J.C.S. Chem Comm. 1979,91. 134 G.Christou C. D. Garner T. J. King C. E. Johnson and J. D. Rush J.C.S. Chem. Comm. 1979,503. The Transition Elements 145 contains a twelve-atom rectangular cluster (alternating metal and and a similar result was found 136 for [(W2S8Aa) (PPh2Me)4].A number of W-Cu-S structures have been examined,137 including that of {(C7H7)3P}4[(Cu4W202S6)], which also has a twelve-member cluster but with a hexagonal cross-section (25). 1.r. evidence supports the oxygen atoms as being external to the cluster. [Cu3WS3Cl{(PPh3),}0] has a cubane structure with the oxygen co-ordinated to the tungsten and the phosphines to the copper The synthesis of the first cluster to contain four different metal atoms has been claimed on the basis of mass spectrometric evidence.'39 [F~COMOWS(ASM~~)C~,(CO)~] is suggested to have a tetranuclear cluster of the four metals. Much of the work in molybdenum cluster chemistry aims to produce model compounds for active Mo centres in enzymes.Molybdenum forms a catalytically active complex with protein sulphydryl gro~ps,'~' thus suggesting that cysteine residues may be a natural binding site. cis-Dioxomolybdenum(v1) cysteinates are able to catalyse 0x0-transfer to aldehydes and tertiary ph~sphines,'~~ and complexes of oxomolybdates with the reduced peptides of bovine insulin are able to effect the reduction of dinitrogen to ammonia.'42 EXAFS data have been ~ ~ eto d ~ evaluate the molybdenum co-ordination environment in sulphite oxidase and xanthine oxidase. Both are found to have a mixture of 0x0- and sulphur-donor ligands. EXAFS data on a number of model compounds are also re~0rted.l~~ The action of cyanide ion on a number of sulphur-containing molybdenum species that Mo=S terminal groups form SCN- with a corresponding reduction (e.g.Mo"' + Mo'") but that bound cysteine and bridging sulphurs are unaffected. The release of SCN- from xanthine oxidase by CN- thus suggests the presence of an Mo=S moiety. A. Miiller H. Bogge E. Koniger-Ahlborn and W. Hellman Inorg. Chem. 1979 18 2301. J. K. Stalick A. R. Siedle A. D. Mighell aiid C. R. Hubbard J. Amer. Chem. Soc. 1979 101 2903. R. Doherty C. R. Hubbard A. D. Mighell A. R. Siedel and J. Stewart Inorg. Chem. 1979,18,2991. 138 A. Miiller T. K. Hwang and H. Bogge Angew. Chem. Internat. Edn. 1979 18 628. F. Richter and H. Vahrenkamp Angew. Chem. Internat. Edn. 1979,18 531. B. J. Weathers J. H. Gate and G.N. Schrauzer J. Amer. Chem. SOC.,1979,101,917. G. Speier Inorg. Chim. Acta 1979,32 139. B. J. Weathers J. H. Gate N. A. Strampach and G. N. Schrauzer J. Amer. Chem. SOC., 1979,101,925. S. P. Cramer H. B. Gray and K. V. Rajagopalan J. Amer. Chem. SOC.,1979,101 2772. "'T. D. Tullius D. M. Kurtz jun. S. D. Conradson and K. 0.Hodgson J. Amer. Chem. SOC., 1979,101 2776. J. M. Berg K. 0.Hodgson S. P. Cramer J. L. Corbin A. Elsberry N. Pariyadath and E. I. Stiefel J. Amer. Chem SOC., 1979,101 2774. 146 P. C. H. Mitchell and C. F. Pygall J. Inorg. Biochem. 1979 11 25. 146 F. A.Hart P. Thornton and J.Newbery Metal-Metal-bonded Species. A review of metal-metal-bonded species with a bond order of four contains much information about Group VIA metal^.'^' Structures of two chromium species [Cr,(PhNNNPh),] and [Cr,{MeNC(Ph)NMe}4] that contain so-called 'supershort' Cr-Cr bonds of 185.8 and 184.3 pm have been ~btained.'~~ It has been that the CrECr species belonging to this 'supershort' category are all devoid of axial ligands whereas the 'normal' species (-220 pm) all have axial ligands.The unusual tungsten complex [W2(Pr'0)6(py)2] contains two four-co-ordinate tungsten atoms linked by a WrW bond with the tungstens rotated into a partially eclipsed mode. Many multiply bonded systems of this type rely for a contribution from a 8-bond which is of maximum strength in the fully eclipsed position although allowing for steric problems small displacements are expected. [Mo,B~~(P~,PCH~CH,ASP~~)~] was suspected of being fully staggered (and therefore with zero &contribution) but the structural analysis reveals that a rotation of about 15" away from the stagger is actually present A number of dimolybdenum species have been shown to have the approximately eclipsed configuration such as [MO~(O~CCH(NH,)R}~(NCS)~],~H~O [M~~(gly),Cl~]nH~O,'~~[Mo~(O~CM~),C~~]~-.~~~ and [Mo,(NCS)~]~-is also eclipsed with what is claimed as the second longest MoEMo bond (218.3pm) and in which the thiocyanates are N-[Mo,(HPO~)~(H,O)~]~-and [Mo,(HPO,),]~-are easily prepared by treating the Mo EM species [Mo2Cl8l4- with orthophosphoric to give purple crystals that are air- and moisture-stable and contain a triple Mo-Mo bond.A more accurate determination of [Mo~(SO~)~]~- giving an Mo-Mo distance of 216.7 pin (and a bond order of 3.5) also shows an eclipsed configuration.156 The carboxylate [Mo,(O,CCF,)~] has been shown by electron diffraction to have a similar gas-phase structure (bridging carboxylates with Mo-Mo =210.5 pm) to that found in the solid pha~e.'~' Solution calorimetry has been used to determine standard enthalpy of formation values for a number of metal-metal multiply bonded species.158 The bond enthalpy (in the gas phase) has been estimated as DMo-Mo= 334 DCr-Mo =249 and DCr-Cr =205 kJ mol-'. J. L. Templeton Progr. Znorg. Chem. 1979 26,211. (a) F. A. Cotton G. W. Rice and J. C. Sekutowski Znorg. Chem. 1979,18 1143; (6) A. Bino F. A. Cotton and W. Kaim ibid. p. 3566. 149 A. Bino F.A. Cotton and W. Kairn J. Amer. Chem. SOC.,1979 101 2506. M. Akiyama M. H. Chisholm F. A. Cotton M. W. Extine D. A. Haitko D. Little and P. E. Fanwick Inorg. Chem. 1979,18,2266. F. A. Cotton P. E. Fanwick J. W. Fitch H. D. Glicksrnan and R. A. Walton J. Amer. Chem. Soc. 1979 101,1752. Is* (a) A. Bino and F. A. Cotton Inorg. Chern. 1979 18 1381; (6) A. Bino F. A. Cotton and P. E. Fanwick ibid. p. 1719. W. Clegg G. D. Garner S. Parkes and I. B. Walton Znorg. Chem. 1979 18 2250. A. Bino F. A. Cotton and P. E. Fanwick Inorg. Chem. 1979,18 3558. Is' A. Bino and F. A. Cotton (a)Angew. Chem. Znternat. Edn. 1979,18,462; (b)Znorg. Chem. 1979,18 3562. A. Bin0 and F. A. Cotton Znorg. Chem. 1979,18 1159. C. D. Garner I. H. Hillier I. B. Walton and B. Beagley J.C.S.Dalton 1979 1279. K. J. Cavell C. D. Garner G. Pilcher and S. Parkes J.C.S. Dalton 1979 1714. 14' The Transition Elements 147 Analysis of electronic absorption spectra of a dimolybdenum phosphonium compound revealed five vibronic progressions which is taken as evidence for a transition where the orbital and vibronic contributions are of similar magnit~de."~ Photoelectron spectroscopy for a series of eclipsed 2-0x0-6-methylpyridine dimetal complexes [M1M2(LL)4] indicates that the M1-M2 6-bonding electrons have ion- ization energies ranging from 6.8 to 5.3 eV for the M'M2 series Cr2 CrMo Mo2 MOW and W2.I6O This compares with a roughly constant value of 7.7 eV for the 7r-and ca. 10.4 eV for the cr-orbitals. Reactions of M-A4Systems.The current dominance of molybdenum and tungsten chemistry by the dinuclear M-M-bonded species has been commented upon. Reaction of PF3 with the dinuclear [M02(BUf)6] leads to an exchange reaction and the formation of the tetranuclear [Mo~(~-F)~(OBU'),]. The Mo_Mo bonds are retained and eclipsed geometry is observed about each Mo-Mo axis. However the two (Mo_Mo) systems are mutually at right-angles held together by the four bridging fluorines. Dimolybdenum tetra-acetate undergoes an exchange reaction with 2-mer- captopyrimidine to produce [M~~(mpy)~], [Mo2(mpy),(CH2C12)] and [M~~(rnpy)~(CH~Cl~)~],'~~ cleavage of the Mo iMo and with alkyl isocyanide~~~~ bond occurs with the production of [Mo(CNR),]" ions. These species possess no crystallographic symmetry at all but the closest description would be that of a capped octahedron.Another substitution process is the production of a triazenido-complex by reaction of a triazene with [W2(NMe2)6] to give [W2(NMe2)4(PhNNNPh)2].164 This may be due to the early transition metals showing high reactivity towards active (protic) hydrogen atoms. The limiting n.m.r. spectrum (at -40 ") shows agreement with the structure observed in the solid phase (26). (26)view along W-W bond A sealed-tube between [W2(NMe2)6] and propan-2-01 gave a tetra- nuclear species [W4(OPri)14H2J. 220 MHz n.m.r. data support a formulation with two bridging hydrogens (27) and the X-ray data reveal the presence of two W=W bonds (length 244.6 pm). lS9 F. A. Cotton and P.E. Fanwick J. Amer. Chem. SOC.,1979,101 5252. 160 B. E. Bursten F. A. Cotton A. H. Cowley B. E. Hanson M. Lattman and G.C. Stanley J. Amer. Chem. SOC., 1979,101,6244. 161 M. H. Chisholm J. C. Huffman and R. L. Kelly J. Amer. Chem. Sac. 1979,101 7100. 162 F. A. Cotton R. H. Niswander and J. C. Sekutowski Inorg. Chem. 1979,18 1149. P. Brant F. A. Cotton J. C. Sekutowski,T. E. Wood and R. A. Walton J. Amer. Chem. SOC.,1979,101 6588. M. H. Chisholm J. C. Huffman and R. L. Kelly Inorg. Chem. 1979 18 3554. lo' M. Akiyama D. Little M. H. Chisholm D. A. Haitko F. A. Cotton and M. W. Extine I. Amer. Chem. SOC., 1979 101 2504. F. A. Hart P. Thornton and J. Newbery R Mechanistic problems in the reactions of [M2R2(NMe2)J (M = Mo or W) with alcohols and CO are discussed,'66 and suggestions made to account for the varying products observed.Carbonylation of MrM alkoxides [M,(OR),] produces a number of different product~,'~' one of the more interesting of which is the M=M carbonyl-bridged species [M0~(0Bu')~(p-C0)]. The solid-state bridging is confirmed by X-ray work and the structure appears to persist in solution (n.rn.r. and i.r. evidence).

ISSN:0260-1818    

DOI:10.1039/IC9797600130

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

F. A. Hart P. Thornton and J. Newbery Part 111 Groups VIIA VIIIA and IB By P. Thornton 1 General The first Specialist Periodical Report on inorganic biochemistry has been published,' with coverage to 1977. The two latest volumes of an established series2 of reviews in this area deal with complexes of nucleotides and their derivatives and with complexes of amino-acids. EXAFS spectroscopy and its applications to metallobiochemistry have been re~iewed,~ as have complexes of compartmental ligands designed to prepare dinuclear complexes of similar or dissimilar metals4 Other reviews concern the reactions of NO when co-ordinated to transition element^,^ and the application of measurements of activation volumes to studies of reaction mechanisms of octahedral complexes.6 General theoretical papers include extended Huckel molecular orbital analyses7 of dinuclear complexes including H3M2L8 which might have a quintuple metal- metal bond for a d5 configuration.A study' of doubly bridged complexes M2Xlo indicates which will decompose to 2MXs units and which to MX6+MX4 with implications for mechanisms of electron-transport reactions. '66 M. H. Chisholm and D. A. Haitko J. Amer. Chem. Soc. 1979 101,6784. "'M. H. Chisholm F. A. Cotton M. W. Extine and R. L. Kelly J. Amer. Chem. Soc. 1979 101 7645. ' 'Inorganic Biochemistry' ed. H. A. 0. Hill Specialist Periodical Reports The Chemical Society London Vol. 1 1979. * 'Metal Ions in Biological Systems' ed. H. Sigel Dekker New York 1979 Vols. 8 and 9. S. P.Cramer and K. 0.Hodgson Progr. Inorg. Chem. 1979,25 1. U. Casellato P.A. Vigato D. E. Fenton and M. Vidali Chem. SOC.Rev. 1979,8 199. J. A. McCleverty Chem. Rev. 1979,79 53. G. A. Lawrance and D. R. Stranks Accounts Chem. Res. 1979,12,403; C. H. Langford Inorg. Chem.. 1979,18,3289. ' A. Dedieu T. A. Albright and R. Hoffmann J. Amer. Chem. SOC. 1979,101,3141. J. K. Burdett J. Amer. Chem. SOC.,1979 101 5217. The Transition Elements Examples of physical studies this year are the use of I3C n.m.r. spectra to discuss the u-and r-bonding in many diamagnetic cyanide complexes9a and to determine the mode of co-ordination of NCE- ions (E = 0,S or Se).96 Determination" of the volumes of activation for methanol exchange with [M(MeOH)6]2+ (M = Mn or Fe) combined with earlier results on Co and Ni suggests that for Mn the process is more associative than dissociative becoming more dissociative towards Ni.The far4.r. and Raman spectra of [M(py)Xz] complexes (M=Mn Co or Ni X=C1 or Br) indicate'' that these have the double-strand structure (1). Spectroscopic studies of PY PY PY PY PY complexes of bivalent Fe Co Ni and Pd with chiral quinonedioximes showed" some ligands co-ordinated through two N atoms others through one N and one 0. The electric conductance of solid [M(mnt),]"- salts (M = Fe or Ni n = 1 or 2) depends on the ease of disproportionation of the metal ions and the size and redox capacities of the counter- cation^.'^ Interesting preparations involving many metal ions include the i~olation'~ of [PFJ salts of complexes of the weakly basic ligands NSF3 or POF with many bivalent metal ions giving [ML4]'+ or Ag' forming [AgLz]+ in liquid SO,.The new macrocyclic ligand (2) related to edta forrn~'~ a variety of complexes with bivalent Co Ni and Cu; most of the complexes are considered to show co-ordination through two N and two 0 atoms but [Cu,X][X = (2)] is antiferromagnetic and it is suggested (a)J. J. Pesek and W. R. Mason Znorg. Chem. 1979,18,924; (b)J. A. Kargol R. W. Crecely and J. L. Burrneister ibid.,p. 2532. lo F. K. Meyer K. E. Newman and A. E. Merbach J. Amer. Chem. SOC.,1979,101 5588. M. Goldstein and R. J. Hughes Znorg. Chim. Acra 1979 37 71. '* A. Nakarnura A. Konishi and S. Otsuka J.C.S. Dalton 1979,488." D. R. Rosseinsky and R. E. Malpas J.C.S. Dalton 1979 749. l4 R. Mews J.C.S. Dalton 1979 278. H. Hafliger and T. A. Kaden Helu. Chim. Acta 1979,62,683. E A. Hart P. Thornton and J. Newbery that one Cu is co-ordinated through four N and the other through four 0 atoms though this does not give a good superexchange pathway and a carboxylate-bridged structure should have been considered. Reaction of the Ba2' complex of (3) with [M(H20)6]2+ salts in MeOH (M =Mn Fe or Co) gives16 contraction of the macro- cycle and formation of [ML(MeOH)(Hz0)]2' complexes [L = (4)]; the X-ray crystal structure of the CO(CIO~)~ complex was determined. Many complexes with pyri- midine-2-one (HL) have been prepared" with bivalent 3d metal ions; with the probable exception of [NiLJ which has an octahedral electronic spectrum the exocyclic 0 is not co-ordinated in contrast to pyrimidine-2-thione.The first preparations of metal complexes with riboflavin 5'-phosphate have been reported;" hydrates of 1:1 complexes are formed and the ligand probably co-ordinates in a unidentate fashion through a phosphate 0 atom. 2 Manganese Technetium and Rhenium Manganese.-Both the mon~clinic'~~ and triclini~'~~ forms of [MnC1(NO)2{PhP(OMe)z}2are examples of rare trigonal-bipyramidal nitrosyls. J The MnNO angles of -165" appear intermediate between the usual linear and bent extremes but the authors propose that in earlier structure determinations of Mn nitrosyls the reported linearity may conceal some disorder and that these may really be similar to the new complexes.The X-ray crystal structure of (PriNH3)MnC1,.2H20 shows that this contains [MnzC16(Hz0)4] units hydrogen- bonded to give a two-dimensional layer,20a and the structure of RbMnF,.H20 comprises chains of alternating [MnF,] and [MnF4(H20)2] octahedra linked through opposite fluorines.20b The electronic spectrum of [Mn(H20)4(02CMe)2] at 15-4K shows exchange effects consistent with magnetic and e.s.r. studies." Work on the biochemistry of Mn and on model compounds has been reviewed." Many [Mn(R3P)X2] complexes (R,P = Bun3P Me2PPh or EtzPPh X = halide or l6 S. M. Nelson F. S. Esho M. G. B. Drew and P. Bird J.C.S. Chem. Comm. 1979 1035. " D.M.L. Goodgame and I. Jeeves Znorg. Chim. Ada 1979,32 157. M. Goodgame and K.W. Johns Inorg. Chim. Acta 1979,37 L559. l9 M,Laing R. H. Reimann and E. Singleton (a) Znorg. Chem. 1979,18,324;(b) ibid. p. 1648. 2o (a)R. D. Willett Acta Crysf. 1979 B35,178; (6)V.KauEiEand P. Bukovec J.C.S. Dalton 1979,1512. " T.E.Wood G. Kokoszka and P. Day Inorg. Chem. 1979,18,2936. 22 G. D. Lawrence and D. T. Sawyer Co-ordination Chem. Rev. 1978 27 173. The Transition Elements 151 pseudohalide) have been ~repared.'~ Some of these have e.s.r. spectra that indicate that they are associated and have curves of O2uptake versus pressure resembling those of haemoproteins with similar enthalpies of oxygenation suggesting co- operative mechanisms. Magnetic and i.r. electronic and e.s.r. spectral studies2 show that the product of the oxygenation of Mn" phthalocyanine is an Mn"'-02- complex unlike that from [Mn(tpp)] which is an MnIV-02'- complex with bidentate peroxide.The oxygenation of Mn" complexes of many quadridentate salicyl- aldimines gives25 antiferromagnetic complexes [MnLO] whose e.s.r. spectra suggest they contain two 0 atoms bridging two MnrV atoms. The MnNO unit in [Mn(NO) (tpp)] is linear with the Mn atom 0.34 8,out of the N4plane much further than Fe or Co in analogous compounds Mn being considered better for T-interaction with The 'H and 31P n.m.r. spectra of the Mn" complex of NADP shows2' that the Mn is bonded to 0 from all three phosphates and is between the bases but closer to adenine. The preparation decarboxylation and transcarboxylation of [(MeO)Mn02CNC2H4NHCO] a model for pyruvate carboxylase and trans-carboxylase have been described.28 Technetium and Rhenium.-The first detailed rep~rt'~ of thionitrosyl complexes includes the preparations of [ReClX(NS)(PR,),] and [ReC12X(NS)(PR3),] (X = C1 or Br).The structures molecular orbitals electronic and Raman spectra and redox properties of quadruple metal-metal bonds have been reviewed.30a New examples of Re-Re bonds probably occur in 'elder-coloured' [Re2F8]'- ( vRe-Re 320 ~m-'),~'~ [Re2C14(02CCMe3)2] (two trans -bridging pivalate~),~'~ [Re2C13(02CCMe3)3]co (chains of dimers linked by axial Cl),30c and [Re2(2-Opy),Cl2] (each Re bonded to two cis-N two cis-0 and Cl).30d The compound formerly believed to be (BU,N),[R~~(NCS),(CO)~] in which has been shown3' to be (BU.,N)~[R~~(NCS)~~] two octahedrally co-ordinated Re atoms in oxidation state 3.5 share an edge (Re-Re 2.613 8,)with two ligands bridging through their N atoms.This is the first report of this type of bridging and the anomalous i.r. spectrum it causes led to the earlier attribution to CO. New complexes in higher oxidation states include the first Schiff -base complexes of Re among them [ReC12X] [ReOClX] and [Re203X2] (X = quadridentate ligand of sal'en type); the last of these have i.r. n.m.r. and Raman spectra suggesting that they have the linear O=Re-0-Re=O Rein~estigation~~" of the reduction of [TcO,]- by H3P02 in HCl showed that [TcOCl,]- was formed. Another interesting 23 C. A. McAuliffe H. Al-Khateeb M. H. Jones W. Levason K. Minten and F.P. McCullough J.C.S. Chem. Comm. 1979,736. 24 A. B. P. Lever J. P. Wilshire and S. K. Quan J. Amer. Chem. SOC.,1979 101 3668. 25 S. J. E. Titus W. M. Barr and L. T. Taylor Znorg. Chim. Acra 1979,32 103. 26 W. R. Scheidt K. Hatano G. A. Rupprecht and P. L. Piciulo Znorg. Chem. 1979,18,292. *' M. K. Green and G. Kotowycz Canad. J. Chem. 1979,57,2434. 28 T. Tsuda Y. Chujo T. Hayasaki and T. Saegusa J.C.S. Chem. Comm. 1979,797. 29 M. W. Bishop J. Chatt and J. R. Dilworth J.C.S. Dalton 1979 1. 30 (a)J. L. Templeton Progr. Znorg. Chem. 1979 26,211; (6)G. Peters and W. Preetz 2. Naturforsch. 1979,34b 1767; (c)F. A. Cotton L. D. Gage and C. E. Rice Znorg. Chem. 1979,18 1138; (d)F. A. Cotton and L. D. Gage ibid. p. 1716. 31 F. A. Cotton A. Davison W. H. Ilsley and H.S. Trop Znorg. Chem. 1979,18 2719. 32 A. R. Middleton A. F. Masters and G. Wilkinson J.C.S. Dalton 1979 542 33 (a)F. A. Cotton A. Davison V. W. Day L. D. Gage and H. S. Trop Znorg. Chem. 1979,18,3024;(6) R. W. Thomas G. W. Estes R. C. Elder and E. Deutsch J. Amer. Chem. SOC.,1979,101,4581. F.A. Hart P. Thornton and J. Newbery Tc complex is the lipophilic [TcOC12X] [X = hydrotripyrazolylborate (5)] which may be useful for Tc radiopharmacy; the authors briefly this subject. ReOC1 has been used3 to prepare a new silylamide [ReO{N(SiMe3)2}3] and new alkoxide complexes [ReO(OBu'),] Li[ReO(OPr')J and [Re203(0Me)6]; the structure of the RYY N-N ReO, 1 Me,SiO-Re\,ReqOSiMe,,NBu BUN ,o BUN 'O' NBu I LN SiMe (6) R/&AR (5) R = H refs.336,39,243 R = Me ref. 263 last of these has been determined. ReCl reacts with NCl to form35 [ReNCl,] whose X-ray crystal structure shows it to contain square-pyramidal units with the axial nitrogen bonded to a neighbouring Re (Re=N 1.58 A Re-N 2.48 A). In the new anion [ReC12(H20)03]- the three oxide ligands adopt the fac-con- fig~ration.,~ The first organoimido Re"" complexes have been reported,,' viz [Re(OSiMe,)(NBu'),] and [Re3(NB~')405(OSiMe3)3], which has a bridging [Re04]- ligand (6). 3 Iron Ruthenium and Osmium Iron(II).-The new complex [Fe2{PhP(C2H4PPh2)2}2(SH)3]+ contains three bridging SH-ligands.,* There have been more structural and magnetochemical reports on spin-state isomerism in Fe" compounds. [FeX,] [X = (5)] a sharp rise in p when heated to 391 K but a more gentle fall when the warm sample is cooled.Contrary to a previous report [Fe(2,9-Me2phen)2(NCS)2] is high-spin at all temperatures the slightly lower values of p at 2 K being attributed to zero-field ~plitting.~' Further on [Fe(2-pi~olyamine)~]~+ salts shows that the cation in the high-spin ethanol solvate of the C1- salt has the mer-configuration whereas the dihydrate is the fu~-isomer.~l~*~ The Fe-N bonds are an average of 0.18 8 longer in the high-spin and in the methanol ~olvate.~~~ Alcohol solvates of the C1- and Br- salts 34 P. Edwards G. Wilkinson K. M. A. Malik and M. B. Hursthouse J.C.S. Chem. Comm. 1979 1158. 35 W. Liese K. Dehnicke I. Walker and J. Strahle 2. Natutforsch. 1979 34b 693.T. Lis Acta Cryst. 1979 B35 1230. 37 W. A. Nugent and R. L. Harlow J.C.S. Chem. Comm. 1979 1105. M. di Vaira S. Midollini and L. Sacconi Znorg. Chem. 1979 18 3466. 39 B. Hutchinson L. Daniels E. Henderson P. Neill G. J. Long and L. W. Becker J.C.S. Chem. Comm. 1979,1003. 40 B. W. Dockum and W. M. Reiff Inorg. Chim. Acta 1979 35,285. 41 (a)A. M. Greenaway and E. Sinn J. Amer. Chem. Soc. 1978,100 8080; (b)A. M. Greenaway C. J. O'Connor A. Schrock and E. Sinn Inorg. Chem. 1979,18,2692; (c) B. A. Katz and C. E. Strouse J. Amer. Chem. SOC., 1979,101 6214. The Transition Elements 153 show sharp conversion to low-spin forms at 130-90 K but removal of the alcohol results in some high-spin proportion down to 4 K.41a*bA doublet-quartet equi- librium was found in [FeL(NO)](BF4) (L= tetramethylcyclam (7)].42 The ob~ervation~~ of similar volumes of activation for the CN- and OH-substitu-tion of [Fe(bi~y)~]~+ suggests that the rate-determining step is a and [Fe(~hen)~]~' dissociation.An earlier report of the acid solvolysis of the latter cation in DMSO is suggested44 to be really a study of the formation of [Fe(~hen)~Cl~]. The partial oxidation of Fe" complexes of c2042-or c4042-with halogen or 1,4-benzoquinone gave mixed-valence compounds [Fe(C204)(H20)1.4Br0.6] [Fe(C204)(H20)o.,(C6H4~2)o.05], and [Fe(C404)(py)11.S] which probably have linear chain structures with the oxidation states randomly distributed; the oxalate complexes are ~emi~~nd~~tor~.~~ Iron(III).-Simple compounds have received more attention than usual.Anomalies in the Mossbauer spectrum of P-FeO(0H) were by recognizing the presence of [Fe(O,OH)6] octahedra and other Fe3' in other channels in the structure giving two overlapping doublets. The X-ray crystal structure that FeC13.zH20 is really [Fe(H20),C12]+[FeCl,]-.H20, the first example of the cis-configuration of the cation. The probably trigonal-bipyramidal [FeC1,I2- has been prepared48 as the [MeN(C2H4),NMeI2' salt. Neutron diffraction Mossbauer and magnetic show that Fe2(S04)3 becomes antiferromagnetic at about 30 K but the two different Fe environments result in non-equivalent magnetizations giving a steep maximum in x at 23.4 K. The crystal structure of the Ph4P+ salt of [Fe2(CN)IO(NH3)]4-,formed by the reaction of [Fe(CN)6I3- with [Fe(CN)s(NH3)]2- showsSo two [FeC5N] units with the NH3 cis to the bridging CN-.Iron(I1) can reduce [Fe(CN)6]3- in liposome using Methylene Blue as a photo~ensitizer.'~ Tris-semiquinone complexes of Fe'" show 42 K.D. Hodges R. G. Wollmann S. L. Kessel D. N. Hendrickson D. G. van Derveer and E. K. Barefield J. Amer. Chem. SOC. 1979 101,906. 43 G. A. Lawrance D. R. Stranks and S. Suvachittanont Znorg. Chem. 1979 18 82. l4R. D. Gillard Znorg. Chim. Acta 1979 37 103. 45 J. Wrobleski and D. B. Brown Znorg. Chem. 1979 18 2738. 46 J. H. Johnston and N. E. Logan J.C.S. Dalton 1979 13. 47 J. T. Szymariski Acta Cryst. 1979 B35,1958. 48 C. S. Creaser and J. A. Creighton J. Znorg. Nuclear Chem. 1979,41,469. 49 G.J.Long G. Longworth P. Battle A. K. Cheetham R. V. Thundathil and D. Beveridge Znorg. Chem. 1979 18 624. 50 P. Roder A. Ludi G.Chapius K. J. Schenk D. Schwarzenbach and K. 0.Hodgson Znorg. Chim. Acra 1979 34 113. 51 Y.Sudo and F. Toda J.C.S. Chem. Comm. 1979 1044. F. A. Hart P. Thornton and J. Newbery antiferromagnetism attributed" to interactions between the unpaired electrons on metal and ligand. Mossbauer spectra that frozen coloured solutions from the reaction of phenols with FeCI contain Fe" if any H20 is present but Fe"' in anhydrous MeOH. Antiferromagnetic [PcFe02FePc] (Pc = phthalocyanine) has been isolated54 from the reaction of PcFe with O2 under N2 in DMSO. At pH 3.94-5.10 solutions of [FeLClJBF [L = (S)] contain [FeL(H20)(OH)]2' ,Me cations and catalyse the decomposition of H202 better than any other model complex.5s Haem Proteins and Porphyrin Complexes.-An earlier reports6" of the X-ray crystal structure of erythrocruorin a monohaem protein has been ~upplemented~~' by the 1.4 8 resolution of structures of the Fe" and Fe'" forms with co-ordinated H20 CN- CO or 02.The Fe-N4 plane distance varies by only 0.15 8 in this series compared with a variation of 0.22 8 between deoxy- and oxy-myoglobin (resolution 2.0 A FeOO angle 121" Fe-0 1.98, 0-0 1.4 The structure of cytochrome c3 from Desulfovibrio desuffuricans (2.5 8 resolution) contains four non-parallel haems surrounded by one polypeptide chain but open to the environ- ment.Fe is also co-ordinated by histidyl residues." Azotobacter vinefandii produces cytochrome bs57.s,which was by electron microscopy amino-acid analysis Mossbauer spectrum and magnetochemistry to have a molecular weight of ca.660 000 and to contain 12 haem units and 1600 Fe atoms in a ferritin-type core so this cytochrome may be the bacterium's Fe or electron storage protein. Studies of carp haemoglobin that azidomet-Hb is 90% high-spin in the T state but 55% high-spin in the R state. The authors found that resonance Raman (rR) spectra may be sensitive to deformations of a high-spin haem and e.p.r. spectra not but the reverse for low-spin haems. Quantum mechani- cal calculations6' suggest that [HbCO] is an Fe2'(S = 0)-CO(S = 0) complex but [Hb.Oz] is an equal mixture of Fe2'(S = 0)-02(S = 0) with Fe2'(S = 1)-02(S= 1) and clarified electronic spectra by distinguishing internal ligand and Fe bands and '' R.M. Buchanan S. L.Kessel H. H. Downs C. G. Pierpoint and D. N. Hendrickson J. Amer. Chem. SOC., 1978,100,7894. 53 J. Silver I. E. G. Morrison and L. V. C. Rees Inorg. Nuclear Chem. Letters 1979,15,433. 54 I. Collimati Znorg. Chim. Acta 1979,35 L303. 55 A. C.Melnyk N. K. Kildahl A. R. Rendina and D. H. Busch J. Amer. Chem. SOC., 1979,101,3232. " (a) E.Weber W. Steigemann T. A. Jones and R. Huber J. Mol. Biol. 1978 120 327; (b) W. Steigemann and E. Weber ibid. 1979 127 309; (c) S.E.V. Phillips Nature 1978 273 247. '' R. Haser M. Pierrot M. Frey F. Payan J. P. Astier M. Bruschi and J. Le Gall Nature 1979,282,806. '* E.I. Stiefel and G.D. Watt Nature 1979 279 81. 59 D.M.Scholler and B. M. Hoffmann J. Amer. Chem. SOC.,1979,101,1655. 6o D. A. Case B. H. Huynh and M. Karplus J. Amer. Chem. SOC.,1979,101,4433. The Transition Elements charge-transfer transitions. A kinetic study61" showed that oxidation of haem proteins by Cu" complexes could involve an outer-sphere electron transfer through the haem edge thk rate depending on the potential of the Cu"/Cu' couple. However dipicolinate (9) complexes of Fe" or Co"' reduce and oxidize respectively the oxidized and reduced forms of horse heart cytochrome c and Pseudomonas aeruginosa cytochrome c551 much faster than edta complexes probably because the pyridine N can co-ordinate the (9) The X-ray crystal structure (2.8 A resolution) of [HbmNO] shows62 that the FeNO angle is 145"; the structural similarity to [Hb.02] is reflected in similar kinetic behaviour which is unlike that of [HbCO].In azide met-Hb (2.8 A resolution) the N3- anion is co-ordinated at an angle to the haem plane,63 in contrast to perpendi- cular CN-. Solutions of the azide complex of Fe"' haem octapeptide prepared from horse heart cytochrome c show a singlet-quintet spin equilibrium with similar enthalpy and entropy values to many natural haem Magnetic anisotropy rneas~rements~~ of [Fe(tpp)] (tpp =tetraphenylporphyrin) show that this has a 3A2ground state. The reaction of CO with [Fe(tpp)(imH)] (imH =imidazole) is faster than with [Fe(tpp)(im)] in contrast to the theory of haem action which suggests that formation of a strong hydrogen bond with the NH of imidazole converts the low-affinity T state into the high-affinity R state.66 The synthesis and structure have been described6' of the [Na(cryptand)]' salts of [Fe(tpp)(SEt)]- and its adduct with CO the complex being the first structurally characterized model for the reduced state of cytochrome P-450.The synthesis structure and electrochemistry of [Fe(tpp)(tht),].tht (tht = tetrahydrothiophen) and show6' that the Fe-S distances are not sensitive to (z :m = tetraphenylporpbyrinate residue W (10) 61 (a)M. A. Augustin and J. K. Yandell Inorg. Chim. Acfu 1979,37,11; (b)A. G. Mauk C. L. Coyle E. Bordignon and H. B. Gray J. Amer. Chem. Soc. 1979,101 5054. 62 J. F.Deatherage and K. Moffat J.Mol. Biol. 1979,134,401. 63 J. F.Deatherage S. K. Obendorf and K. Moffat J. Mol. Biol. 1979,134,419. 64 Y.-P.Huang and R. J. Kassner J. Amer. Chem. SOC.,1979,101 5807. 65 P. D. W.Boyd D. A. Buckingham R. F. McMeeking and S. Mitra Inorg. Chem.. 1979 18 3585. J. C. Swartz M. A. Stanford J. N. MQY B. M. Hoffmann and J. S. Valentine J. Amer. Chem. SOC.,1979 66 101,3396. 67 C. Caron A. Mitschler G. Rivibre L. Ricard M. Schappacher and R. Weiss J. Amer. Chem. SOC.,1979 101,7401. 68 T.Mashiko J.-C. Marchon D. T. Musser C. A. Reed M. E. Kastner and W. R. Scheidt J. Amer. Chem. Soc. 1979 101 3653. F. A. Hart P. Thornton and J. Newbery changes in the oxidation state of Fe so assisting redox reactions of cytochrome c that thioethers are better ligands to FeIII than was previously believed and that replace- ment of imH by thioether gives a 160 mV shift in Ee for the Fe"'/Fe" couple.The porphyrin (11)forms an Fe" complex in which the imidazole group co-ordinates as Et Me well as the porphyrin nitrogens. This complex is very similar to R-state Hb in its spectra and in the kinetics and equilibria of its reactions with O2and CO the first model complex to behave thus. Many other compounds with related ligands were described and their n.m.r. spectra studied.69 The Fe" complex of the capped porphyrins (12) form 1:1 and 1:2 complexes with 1-methylimidazole; the second -. -I = COz(CHz)nO~6~4 azole molecule is only weakly attached but this complex reversibly an adduct with 02.There is a marked difference in the 0,-binding ability as n is altered which is attributed to an increase in the conformational strain of the ligand after ~xygenation.~~' Workers with capped or picket-fence porphyrin complexes are reminded71 that the apparent similarity of their 02-binding properties to those of myoglobin may mask cancelling differences in enthalpy and entropy terms.The FelIr 69 T. G.Traylor C. K. Chang J. Geibel A. Berzinis T. Mincey and J. Cannon J. Amer. Chem. Soc. 1979 101,6716. 'O (a)J. R. Budge P. E. Ellis R. D. Jones J. E. Linard F. Basolo J. E. Baldwin and R. L. Dyer J. Amer. Chem. Soc. 1979 101,4760; (b)J. R. Budge P. E. Ellis R. D. Jones J. E. Linard T. Szymanski F. Basolo J. E. Baldwin and R. L. Dyer ibid. p. 4762." M.-Y. R. Wang B. M. Hoffman S. J. Shire and F. R. N. Gurd J. Amer. Chem. SOC.,1979,101,7394. The Transition Elements 157 complex of tetrakis-(4-N-methylpyridyl)porphyrinwas the most efficient super- oxide dismutase catalyst of a number of Fe complexes studied; the complex is decomposed by H202in an 02-generating system but can be protected by traces of cat alase .72 There have been many spectroscopic and magnetic studies of porphyrin complexes. The 'spin marker' bands in the rR spectra of Fe'" porphyrin complexes in DMSO-bands that change frequency as the spin state changes-are best explained73 by a change in size of the ring cavity and distortion of the ring from planarity giving changes of the r-overlap between Fe and the ligand r*-orbitals but some anomalies remain; the authors also consider that horseradish peroxidase and cytochrome c' contain five- not six-co-ordinate Fe"'.Electronic spectra1 studies show7 that the equilibrium (1)is shifted to the right by the addition of phen when L is 2L +[Fe(tpp)Cl] + [Fe(tpp)L2]++C1-imH but not when L is 1-Me-im as phen can no longer 'chelate' the substituted hydrogen atom. Doublet-sextet spin equilibria have been in solid and solutions for 'hemichrome' salts [Fe(oep)L2]X (oep = octaethylporphyrin L = py or 3-Clpy X = ClO or PF6). The 'H n.m.r. spectra of high-spin FeI'I complexes of natural porphyrins and their deuteriated derivatives that in-plane asym- metry in proteins arises from haem-apoprotein interactions and that the ratio of the chemical shifts of the pyrrole and methyl protons may indicate whether the sixth co-ordination site is occupied.The 13C n.m.r. spectrum of [Fe(tpp)Cl] has been rea~signed,~~' with a signal previously thought to come from a pyrrole carbon now assigned to an ortho-phenyl carbon with an unexpectedly large chemical shift. [Fe(EtOH),(tpp)](BF,) is very easily prepa~ed'~ by the reaction of [Fe2(tpp)20] with HBF in EtOH-CHC1,; its e.s.r and Mossbauer spectrum and its magnetic moment show it is a high-spin complex unlike the oep analogue and the X-ray crystal structure shows a rather long Fe-N bond of 2.03 A. [Fe(tpp)X] complexes (X= c104,BF4,PF6 SbF6 or CF3S03) have been prepared by reaction of [Fe(tpp)Cl] with AgX in THF. With ~300 =4.5-5.3 pBa mixed quartet-sextet spin state is indicated but these are not in thermal equilibrium; it is suggested that the anomaly of C104- inducing a lower spin for FeI'I than N3- or OMe- could be explained if the porphyrin ligand field showed dependence upon the axial ligand.The ClO,- salt has a rather short Fe-N bond (2.001 A) and its n.m.r. visible Mossbauer and e.s.r spectra in solution show mostly high-spin character with the e.s.r spectrum similar to cyto- chrome c'. The authors found some orientation of 'random' polycrystalline samples during magnetic meas~rements.~~ 72 R. F. Pasternack and B. Halliwell J. Amer. Chem. SOC.,1979 101 1026. 73 T. G.Spiro J. D. Stong and P. Stein J. Amer. Chem. SOC.,1979 101 2648. 74 A. L. Balch J. J. Watkins and D. J. Doonan Inorg.Chem. 1979,18 1228. 75 H. A. 0.Hill P. D. Skyte J. W. Buchler H. Lueken M. Tom A. K. Gregson and G. Pellizer J.C.S. Chem. Comm. 1979,151. 76 (a)D. L. Budd G. N. La Mar K. C. Langry K. M. Smith and R. Nayyir-Mazhir J. Amer. Chem. SOC. 1979 101 6091; (6)J. Mispelter M. Momentau and J. M. Lhoste J.C.S. Chem. Comm. 1979 808. 77 P. Gans G. Buisson E. DuBe J.-R. Regnard and J.-C. Marchon J.C.S. Chem. Comm. 1979 393. 78 C. A. Reed T. Mashiko S. P. Bentley M. E. Kastner W. R. Scheidt K. Spartalian and G. Lang J. Arner. Chem. SOC.,1979,101 2948. F. A. Hart P. Thornton and J. Newbery Et Et Complexes of the type [FeLX] [L =octaethylisobacteriochlorin (13) X = C1 or SAr] have been ~repared'~ as models for sirohaem the site of substrate binding in nitrite and sulphite reductases; the thiophenolate complexes have the closer electrochemical properties and electronic spectra to the protein suggesting that this has an S-donor group.The 'H and 13C n.m.r. spectra of dicyanoiron(II1) complexes of the porphyrins (14) (R' R2 varied among H Et CH2CH Br SO3,MeCO HCO and CN) revealed the asymmetric charge distribution in the pyrrole rings and suggested that this was responsible for the dimerization of low-spin Fe'" porphyrins by the T-T interaction between the best donor ring of one molecule with the best acceptor ring on another.80a The electrochemical oxidation of [Fe2(tpp)20] to mono- and di-cations and the oxidation by the latter of another Fe'" porphyrin complex were also studied by n.m.r.to seek comparisons with peroxidases and other haemoproteins possibly containing Fe'V.806 Iron-Sulphur Proteins and Model Complexes.-The X-ray crystal structure of Azotobucter vinelundiiferredoxin (4.0A resolution) shows the usual Fe4S4 core but probably also an Fe2S2 core; this would be the first Fe-S protein to contain different cores.81 The EXAFS spectra on the oxidized and reduced forms of Fez and Fe Fe-S 79 A M. Stolzenberg L. 0.Spreer and R. H. Holm J.C.S. Chem. Comm. 1979 1077. (a)G.N. La Mar D. B. Viscio K. M. Smith W. S. Caughey and M. L. Smith J. Amer. Chem. SOC.,1978 100 8085 and two following papers; (b)M. A. Phillippi and H. M. Goff,ibid. 1979 101 7641. C. D. Stout Nature 1979 279 83. The Transition Elements 159 proteins and Holm's model compounds are very similar with little change between solid and solution but distinction between oxidized and reduced forms.82 The I9F n.m.r.spectra of products from core extrusion reactions with 4-CF3C6H4SH can be used to determine the Fe-S core when a protein contains another chromophore such as Mo haem or flavin species. Thus milk xanthine oxidase contains four Fe clusters and nitrogenase from Clostridium pasteurianum or Azotobacter vinelandii contain at least two Fe4 sites in both oxidized and reduced forms and one Fez site in the oxidized form but much Fe remained ~nextruded.~~ The reaction of denatured Clostridium pasteurianum rubredoxin with Fe2' Fe3' and S2-in aqueous DMSO gives a solution with an electronic spectrum like that of an [Fe4S4(SR),I2- ferred~xin.~~ A study of the oxidation of reduced parsley Fez ferredoxin by a variety of metal complexes and the blocking of this process by [Cr(NH3)6I3' or [Cr(en)3]3' indicated the protein had three different reaction sites which operated according to the ligands on the oxidants." An improved synthesiss6 of [Fe4S4(SR),I2- complexes (R = C2H40H,But,or Ph) uses the reaction of FeCI or FeCI with S and LiSR or NaSR in MeOH under N2.The Fe4S4 cube in (Et4N),[Fe4S4(SCH2Ph)4] is the first found to have a C2 rather than D2d distortion.This is attributed to solid-state factors since the anion and many analogues87b are elongated cubes in solution as is the solid SPh analogue. This contrasts with the various dianions which all have the compressed DZdstructure and the authors conclude that the Fdred structure is more susceptible to environmental factors than the Fd, Reaction of [Fe(SPh),I2- with (PhCH2)2S3 gives [Fe2S2(SPh)4]2- or the new anion [Fe2SI2l2- which has two S atoms bridging two FeS chair rings.It is suggesteds8 that trisulphides may be a source of 'inorganic' sulphur in ferredoxin biosynthesis. To study the role of [Fe4S4(SR),]"- clusters in hydrogenase in which this cluster is the only metal species the dianion was attached to silica gel with HSC3H6Si~ groups but the system did not adsorb H2 or CO and showed no catalytic a~tivity.'~ The preparation structure and properties of many Fe-Mo-S cubane structures (15) have been reported" as aids to the study of nitrogenase. Mossbauer spectra favour 2$ oxidation state in these complexes and nitrogenase but EXAFS results suggest that (15b) is closer to nitrogenase than complexes with three bridging mercaptide~.~~~ Thiolate exchange reactions on (15d) introduced the SC2H40H B.-K.Teo R. G. Shulman G. S. Brown and A. E. Meixner J. Amer. Chem. SOC.,1979,101 5624. 83 G. B. Wong D. M. Kurtz R. H. Holm L. E. Mortenson and R. G. Upchurch J. Amer. Chem. SOC. 1979,101,3078. 84 G. Christou B. Ridge and H. N. Rydon J.C.S. Chem. Comm. 1979,84. '' F. A. Armstrong R. A. Henderson and A. G. Sykes J. Amer. Chem. SOC., 1979,101,6912. 86 G.Christou and C. D. Garner J.C.S. Dalton 1979 1093. *' (a)J. M. Berg K. 0. Hodgson and R. H. Holm J. Amer. Chem. SOC.,1979 101 4586; (6) E.J. Laskowski J.G. Reynolds R. B. Frankel S. Foner G. G. Papaefthymiou and R. H. Holm ibid. p. 6562. D. Coucouvanis D.Swenson P. Stremple and N. C. Baenziger J. Amer. Chem. SOC.,1979,101,3392. 89 R. G. Bowman and R. L. Burwell J. Arner. Chem. Soc. 1979,101,2877. 90 (a)S. R. Acott. G. Christou C. D. Garner,T. J. King F. E. Mabbs and R. M. Miller,Inorg. Chim. Acta 1979,35 L337; (b)T.E.Wolff J. M. Berg K. 0.Hodgson R. B. Frankel and R. H. Holm J. Amer. Chem.SOC.,1979,101,4140;(c) T.E.Wolff J. M. Berg P. P. Power K. 0.Hodgson R. H. Holm and R. B. Frankel ibid. p. 5454;(d)G. Christou C. D. Garner F. E. Mabbs and M. G. B. Drew J.C.S. Chem. Comm. 1979,91;(e)G. Christou C. D. Garner R. M. Miller and T. J. King J. Inorg. Biochem. 1979,11 349; (f)G. Christou C. D. Garner T.J. King C. E. Johnson and J. D. Rush J.C.S. Chem. Comm. 1979 503. F. A. Hart P. Thornton and J. Newbery RS/ 'SR (15) a; M=Mo R=Et X=Y=Z=SEt b; M=Mo R=Et X=Y=SEt,Z=S c; M=Mo R=Et X,Y,Z=Fe(SEt) d; M=Mo R=Ph X=Y= Z=SPh e; M=W R=Et X=Y=Z=SEt f; M=W R=Ph X=Y=Z=OMe group at all nine positions to give the first water-soluble complex of this type.90d Complexes (15a) and (15e) are isomorphous but unlike (15a) the reduction of the W complex is irrever~ible.~~' In complex (15f) the Mossbauer spectrum suggestsgof that Fe has the oxidation state 2.5 and W 3.5. Following an earlier report that acid hydrolysis of nitrogenase released [MoS4I2- the new complex (Me4N)6[Fe4M04S20] was prepared by the reaction between Me4" salts of [MoS4I2- and [Fe4S4(SB~')4]2-; the complex is thought to comprise an Fe4S4 cube co-ordinated by four MoSd2- with five-co-ordinate Fe.'lU It does not readily exchange MoSd2- with PhSH.The reaction between the Et4N' salts of [MoS4I2- and [Fe(SPh)4]2- gave the new [(PhS)2FeMoS4]2- anion containing (X-ray structure) MO" and tetrahedral Fe"' as rhombic FeMoSz Other Iron Proteins.-Microbial iron transport processes have been briefly reviewed.92 Further results on the Fe"'-enterobactin (16) system show that the complex's formation constant approximately 1052and that protonation gives a HO OH (=5c0-NH-cH2-(17) /3 (16) change from catecholate to salicylate bonding.93b The model ligand 1,3,5-C6H3X3 [X= (17)] an Fe*'' complex with formation constant lo4'.' and may be useful for chelation therapy.946 A kinetic study95 of the removal of Fe from transferrin by sequestering agents such as (18) shows that this process can occur under physiological conditions with implications for treatment of iron overload.91 (a) H. C. Silvis R. H. Tieckelmann and B. A. Averill Inorg. Chim. Acfa 1979 36 L423; (b) D. Coucouvanis E. D. Simhon D. Swenson and N. C. Baenziger J.C.S. Chem. Cornm. 1979,361. 92 K. N. Raymond and C. J. Carrano Accounts Chem. Res. 1979,12 183. 93 (a)W. R. Harris C. J. Carrano and K. N. Raymond J. Amer. Chem. Soc. 1979,101,2213;(b)W. R. Harris C. J. Carrano S. R. Cooper A. E. Avdeef J. V. McArdle and K. N. Raymond ibid. p. 6097. 94 (a)W. R. Harris F. L. Weitl and K. N. Raymond J.C.S. Chem. Comm. 1979,177; (6)F.L. Weitl and K. N. Raymond J. Amer. Chem. SOC., 1979,101,2728. " C. J. Carrano and K. N. Raymond J. Amer. Chem. SOC.,1979,101 5401. 161 The Transition Elements H03sq0H H03p OH H03S O H q ' \ OH OH \ OH co co HN-(CH,)3-N-(CHz)4-NH 1 1 co 1 (18) fron(II1) complexes of aerobactin (19),a dihydroxamate siderophore from Aerobac- ter aerogenes have been described. This is not as effective a chelator as enterobactin but Fe can be removed from it easily after the transport process whereas Fe can only be recovered from enterobactin by destroying the ligand.96 The authors suggest that if there is appreciable Fe in its environment the bacterium will extract it with aerobactin and use enterobactin only if the local concentration of Fe is very low.EXAFS spectra of ferritin and model compounds expecially [Fe3(H2O),0- (NH2CH2C0z)6]C104 suggest that ferritin consists of distorted Fe06 octahedra giving layers of Fe atoms between two close-packed 0 layers. There is only weak bonding between vertical neighbours except at the edges of the layers where two adjacent layers are joined resulting in a series of strips 70 A long piled on top of one another like computer output. Phosphates act as end Finally on this enthralling subject of iron proteins the rR spectrum of pyro- catechase shows it to resemble protocatechuate 3,4-dioxygenase in containing an Fe-tyrosine unit. The tyrosine absorptions are lost when catechol is added probably because the charge-transfer band between Fe and tyrosine is shifted.98 Ruthenium(n).-A convenient new synthesis99 of [RuHzL4] compounds (L= tertiary phosphine or 2L = ditertiary phosphine) starts from [Ru(q"-cod)(q"-cot)].New products from [RuH~(PP~,)~] in which include [RUH~(PP~,),{C~H~(CN)~}] 1,2-dicyanobenzene co-ordinates through only one N atom.loo The n.m.r. spectra of [RUH{N(S~M~,)~}(PP~,)~], the first amido-complex of Ru suggest a tetrahedral structure.lol The 'Hn.m.r. spectra in DMSO show that the published synthesis of [R~(bipy)~Cl~] gives only the cis-isomer. 102a This complex can be converted into [R~(bipy)~(MeOC~H~0Me)]~+, a useful synthetic intermediate.lo2' The first linkage 96 W. R. Harris C. J. Carrano and K. N. Raymond J. Amer. Chem. SOC.,1979,101 2722. 97 S. M. Heald E.A. Stern B. Bunker E. M. Holt and S. L. Holt J. Amer. Chem. Soa 1979 101,67. 98 L. Que and R. H. Heistand J. Amer. Chem. SOC.,1979,101 2219. 99 P. Pertici G. Vitulli W. Porzio and M. Zocchi Znorg. Chim. Acta 1979 37 L521. loo R. 0.Rosete D. J. Cole-Hamilton and G. Wilkinson J.C.S. Dalfon 1979 1618. lo' B. Cetinkaya M. F. Lappert and S. Torroni J.C.S. Chem. Comm. 1979,843. lo* (a)J. D. Burchall T. D. O'Donoghue and J. R. Wood Inorg. Chim. Acta 1979,37 L461; (b)J. A. Connor T. J. Meyer and B. P. Sullivan Znorg. Chem. 1979,18 1388. F. A. Hart P. Thornton and J. Newbery isomers of SO2have been describedlo3 in [Ru(NH3),(S02)CI]CI;the S-bonded form can be converted into the S,O-form photochemically and two other species have been found but not identified.An unusual bridging SO unit occurs'o4 in [Ru(PP~~)~(SO~)(SO,)]~.P~M~ (20). 0 (20) (21) There have been many reports of electronic spectra photochemistry and kinetic studies of ammine complexes. The [Ru(NH3),LI2+ cation [L = 10-methyl-isovalloxazine (21)] is the first octahedral metalloflavin complex and a model of a type of intermediate for inner-sphere electron transfer to Fe-S or Mo biological Kinetic studies of redox reactions of hexa-ammino and hexa-aquo Ru2' and Ru3' ions and of ligand exchange reactions between members of a redox couple show106a that differences in hydration entropies of two species in a redox couple may be related to the difference between the ion's radii -0.1 A for hexa-aquo-ions but other workers attribute'066 differences to the 'structure-making' role of the different cations.Flash photolysis of various [RU(NH~)~L]~' complexes (L=py or derivative) shows that the complexes which give the long-lived intermediates are those that are easily photoaquated and that the transition state probably has py v-bonded to Ru allowing easy protonation of an NH and giving the observed pH dependence of the photoaquation yield.'" Mixed-valence Ruthenium Compounds.-Picosecond flash photolysis of [(NH3)5R~11(py~)R~111(edta)]+ and other complexes with bridging pyrazines shows that the metal-to-ligand charge-transfer (MLCT)state (22a) decays first to another (224 (22b) electronic isomer (22b) before decaying to the ground state."* X-Ray crystal structures have been published'09a of five Ru"*~'~ dinuclear carboxylates and SCF-Xa-SWcalculations109b show that v*-and 8"-orbitals in these complexes are very close in energy and further explain bond lengths electronic spectra and g values.'03 D. A. Johnson and V. C. Dew Znorg. Chem. 1979,18,3273. lo4 I. Ghatak D. M. P. Mingos M. B. Hursthouse and K. M. A. Malik Transition Metal Chem. 1979,4 260. lo' M. 5. Clarke M. G. Dowling A. R. Garafalo andT. F. Brennan J. Amer. Chem. SOC.,1979,101,223. lo6 (a)W. Bottcher G. M. Brown and N. Sutin Znorg. Chem. 1979,18 1447; (6) E. L. Yee R. J. Cave K. L. Guyer P. D. Tyma and M. J. Weaver J. Amer. Chem. Soc. 1979,101 1131. lo' V. A. Durante and P. C. Ford Znorg. Chem. 1979,18 588. C. Creutz P. K. Roger T. Matsubara T. L. Netzel and N.Sutin J. Amer. Chem. Soc. 1979,101,5442. (a)A. Bino F. A. Cotton and T. R. Felthouse Znorg. Chem. 1979,18,2599; (b)J. G. Norman G.E. Renzoni and D. A. Case J. Amer. Chem. SOC.,1979 101 5256. The Transition Elements 163 Products from the reduction by H2 of [RU~(H~~)~O(~~CM~)~](O~CM~) in DMF catalyse the hydrogenation of alkenes and alkynes with one Ru in [RU~(DMF).O(~~CM~)~]+ thought to be the active site.'lo The chemistry of [{Ru~(~~)~O(O~CM~)~}~L]~+ (L =pyrazine or other bridging pyridine-type ligand n = -2 to +3) has been described."'" The bridging ligand probably connects two Ru3 triangular clusters. Intercluster effects were found whose extent depended on L and n. For L = pyz n = 1 or 3 cluster-cluster CT bands or intervalence transitions were seen; intercluster coupling was greater at lower values of n.The new cation [R~~(py),(pyz)~(C0)0~(O~CMe)~~]~' probably consists of two [R~~(py)~o(o~CMe)~] unit; units bridged by pyrazines to an [Ru,(CO)O(O~CM~)~] like the previous example this cluster shows more intercluster effects as reduction increases as if tending to adopt a band During studies of the reactivity of [Ru(NH3),N2I2+ supported on zeolites it was realized'l2 that a wine-red species thought to contain [Ru(NH~)~OH]~' was really the trinuclear 'Ru red' [(NH,),RuORU(NH~)~ORU(NH~)~]~+. Ruthenium-(III) and -(Iv).-The compound described earlier as a convenient form of [Ru(bipy)Cl,] is really [R~(bipy)Cl,].~~~ A magnetic study of polynuclear Ru"' complexes with pyrazine or other bridging heterocyclic amine found no interaction between Ru atoms unlike the mixed oxidation state compounds probably '14 because of less tr-overlap with smaller Ru3'.The cation of [Ru(NH,),X](PF~)~ [X = 1methylcytosinate (23)]has the first crystallographically established exocyclic N-metal bond for a purine or ~yrimidine."~ The preparation electronic spectra and substitution reactions of [Ru(NH,)~(EM~,)](PF~)~ S,Se or Te) have been (E= described.'16 The EMe2 ligand is substituted only slowly probably because of tr-bonding from Ru."~ The unusually fast substitution of I-in such complexes as tran~-[Ru(NH~)~(isn)(H,O)]~+ [isn =isonicotinamide (24)] is explained'" by the Me I occurrence of reduction to Ru" this product catalysing the substitution.A recent example1'* of the fast developing field of the reactivity of transition-metal complexes 110 S. A. Fouda and G. L. Rempel Inorg. Chem. 1979 18 1. 111 (a)J. A. Baumann D. J. Salmon S. T. Wilson and T. J. Meyer Inorg. Chem. 1979,18,2472;(b)J. A. Baumann S. T. Wilson D. J. Salmon P. L. Hood and T. J. Meyer J. Amer. Chem. SOC.,1979 101 2916. 112 C. P. Madhusudhan M. D. Patil andM. L. Good Inorg. Chem. 1979,18 2384. 113 S. Anderson and K. R. Seddon J. Chem. Res. (S) 1979,74. 114 E. C. Johnson R. W. Callahan R. P. Eckberg W. E. Hatfield and T. J. Meyer Inorg. Chem. 1979,18 618. 11s B. J. Graves and D. J. Hodgson J. Amer. Chem. SOC.,1979,101 5608. 116 C. A. Stein and H. Taube Znorg. Chem. 1979,18 1168. 117 D.E. Richardson and H. Taube Inorg. Chem. 1979,18,549. 118 N. Oyama and F. C. Anson J. Amer. Chem. SOC.,1979,101 1634. F. A. Hart P. Thornton and J. Newbery on electrode surfaces describes the substitution of the Ru"'-edta complex on a graphite electrode and gives many references to earlier work. Substitutions of [Ru(edta)(H20)]"-(n= 1 or 2) are associative for Ru'" where the hole in the t2= orbital is said to be suitable for binding an incoming ligand but dissociative for Ru". A recent structure determination'g0 shows that K4[Ru20Cl,o] is not hydrated as an earlier report had proposed. The photochemical decomposition'21 of [Ru(S2CNMe2),] in CHC1 with benzophenone gave a seven-co-ordinate thio- carboxamide complex [RuCl(SzCNMe2)(q2-SCNMe2)], whose 'H n.m.r.spectrum shows it to be non-rigid in CD2C1 above -40 "C. Photochemistry of Ruthenium Bipyridyl Complexes.-This topic is a very active one with hopes of the conversion of solar energy to industrial purposes. The emission spectra of [RuL,(CN),] (L= bipy or phen) and of the mono- and di- protonated forms of these gave bands only for the unprotonated complexes showing that the excited states are strong acids which decompose readily.'" Improved preparation^'^^ of [R~(bipy)~X~] (X = NO2,I N3,CN or malonate) are given by the photochemical substitution of [Ru(bipy),]X2. The time-resolved resonance Raman spectrum of [Ru(bipy),*]'+ is the first vibrational spectrum of an optically generated excited state in a fluid solution and shows bipy modes an average of 61 cm-' lower in energy than in the ground state; it is suggested that electron density is localized on one ligand on the vibrational time-scale.There are two full of the production of H2 from H20under continu- ous irradiation using [Ru(bipy),]'+ as photosensitizer [Rh(bipy),I3+ as relay species N(C2H40H)3as electron donor and colloidal Pt as catalyst. One of these obtains colloidal Pt from K2PtC14 or K2PtC16; the also describes the irradiation of [Rh(bipy),I3+ without a photosensitizer the use of Ir complexes in place of Ru or Rh and the absence of the Pt catalyst. Methylviologen has been used instead of [Rh(bipy),I3+ in a including RuOZ as catalyst for producing O2 as well as HZ,and the use of paraquat gave an appreciable photo~urrent.'~~~ Ru complexes of the bipy derivative (25) allow interesting photochemical systems to be studied as monolayers; 126 luminescence spectra and field-desorption mass spectra T.Matsubara and C. Creutz Znorg. Chem. 1979,18 1956. 120 J.-P. Deloume R. Faure and G.Thomas-David Actu Cryst. 1979 B35,558. 12' G.L. Miessler and L. H. Pignolet Inorg. Chem. 1979,18 210. 12' S. H. Peterson and J. N. Demas J. Amer. Chem. SOC.,1979 101,6571. 123 W. M. Wallace and P. E. Hoggard Inorg. Chem. 1979 18 2934. 124 R. F. Dallinger and W. H. Woodruff J. Amer. Chem. SOC.,1979 101,4391. (a)G. M. Brown S.-F. Chan C. Creutz H. A. Schwartz and N. Sutin J. Amer. Chem. SOC.,1979,101 7638; (b) M. Kirch J.-M. Lehn and J.-P. Sauvage Helu. Chim. Actu 1979 62 1345; (c) K.Kalyanasundaram and M. Gratzel Angew. Chem. 1979,18,701; (d)B. Durham W. J. Dressick and T. J. Meyer J.C.S. Chem. Comm. 1979,381. 126 S. J. Valenty D. E. Behnken and G. L. Gaines Inorg. Chem. 1979 18 2160. The Transition Elements 165 were described. [R~(bipy)~]' has been prepared'27a by the photochemistry of aqueous solutions of [Ru(bipy),I2+. This has a longer lifetime and greater reducing power than [R~(bipy)~]'+ and one mole will generate about 10mol H2 from H20 in the presence of one mole of a Co" macrocyclic complex and Eu2' or a~corbate.'~~~ The coupling of Ru'' to Rh"' can also be achieved in [(NH3)5R~LRh(NH3)5]5+ (L= pyz or ~-CNP~).'~* Osmium.-The first thionitrosyl complexes include [OsC1X2(NS)L2] (L = AsPh, PMe,Ph or ibi~y).~' Various dithiocarbamate (dtc) complexes [O~(dtc)~] [Os2N(dtc),] [O~,(dtc)~]Cl and [Os(dtc),X] (X= C1 I or PPh,) have been prepared; in propylene carbonate [Os(Et2NCS2),] can be reversibly oxidized or reduced to give all species from the dication to the monoanion but in MeCN irreversible oxidation to [Os(MeCN)(Et,NCS,),]' Another new complex of this type is the first of a trithiocarbamate ion thought to be an intermediate in vulcanization [OS~(E~~NCS~)~(E~~NCS~)~]+ (26),with an 0s-0s bond (2.791 A).12" 1 SG C--s 'NEt, / OsCls has been prepared for the first time by the reaction of OsF with BCl below room temperat~re;'~' it is stable in a vacuum or an inert atmosphere at room temperature and is isomorphous with Re2Cllo.Osmium(v1) 0x0-complexes with phen or Me4en have i.r.electronic and 'H n.m.r. spectra consistent with both monomeric [Os02(0H),L] and dimeric [LOsO2(g- O)20s02L]forms for each.I3' Among the products of the reactions of [Os04(quinuclidine)] with alkenes alkynes and dienes are [(R0,)0sL02] (R = organic residue L =quinuclidine) as five-co- ordinate monomers in solution but dimers in the solid state with unsymmetrical bridges e.g. (27) for cy~lohexene.'~~ X-Ray crystal structures of [OsX03] [X = (28)] and [OS(NBU)~O~] show in each case the 0s-N bond is shorter than the 0s-0 bond.', (a) C. Creutz N. Sutin and B. S. Brunschwig J. Amer. Chem. SOC.,1979,101 1297; (6)G. M. Brown B. S. Brunschwig C. Creutz J. F. Endicott and N. Sutin J. Amer. Chem. SOC.,1979 101 1298.J. A. Gelroth J. E. Figard and J. D. Petersen J. Amer. Chem. SOC.,1979,101 3649. (a)K. W. Given S. H. Wheeler B. S. Jick L. J. Maheu and L. H. Pignolet Znorg. Chem. 1979,18,1261; (b) L. J. Maheu and L. H. Pignolet ibid.,p. 3626. R. C. Burns and T. A. O'Donnell Znorg. Chem. 1979,18,3081. 13' C.-H. Chang W. R. Midden J. S. Deetz and E. J. Behrman Znorg. Cbem. 1979,18 1364. 13' M. Schroder A. J. Nielson and W. P. Griffith J.C.S. Dalton 1979 1607. 133 W. A. Nugent R. L. Harlow and R. J. McKinney J. Amer. Chem. SOC.,1979,101,7265. 12' F. A. Hart P. Thornton and J Newbery (27) L =quinuclidine 4 Cobalt Rhodium and Iridium The X-ray crystal structure of [Co(NO)(SO,)(PPh,),] shows that this has a planar Co-SO2 unit unlike the Rh analogue.'34 Cyclic voltammetry studies on [Co2(tri- phos),E3I2' complexes (E=P or As) (29) gave reversible conversion to tri- or Ph2 Ph2 (29) a; M=CoorNi E=PorAs R=Me b; M=RhorIr E=P R=H mono-cations or the uncharged c~mplexes.'~~ reacts with NaBPh4 CO(BF~)~ MeC(CH2PPh2), and CS2 to give a diamagnetic dinuclear CS2-bridged complex (30) one Co being chelated by CS2 the other co-ordinated through the C=S T-bond.'36 Cobalt(II).-Results on simple Co" compounds include the detection of unexpected spiii density on the dx2-,2 orbital in the [COC~,]~- ion of Cs3CoClS by polarized neutron s~attering;'~' this technique might usefully be applied to many more D.C. Moody and R. R. Ryan Inorg. Chem. 1979,18,223;D.C.Moody R. R. Ryan and A.C. Larson ibid. p. 227. '" L.Fabbrizzi and L.Sacconi Inorg. Chim. Acta 1979,36 L407. '" C.Bianchini C. Mealli A. Meli A. Orlandini and L. Sacconi Angew. Chem. 1979,18,673. 13') B. N.Figgis. R. Mason A. R. P. Smith and G. A. Williams J. Amer. Chem. SOC.,1979,101 3673. The Transition Elements problems in transition-metal chemistry. The new anion [Co(OH),I,]- has been prepared'38 by the reaction of [MeNH(CH,CH2),NMe2]I2 with [CoI,{MeN(CH2CH2),NMe2}];its electronic spectrum suggests trigonal-bipyrami- dal geometry giving a rare example of a monomeric hydroxo-complex. Na20 and COOreact under different conditions to give Na4Co03 and Nal,Co,09. The former contains'39a discrete trigonal [Coo3]- ions and the latter twisted chains of four COO units sharing an 0 atom;'396 these are described as the first oxocobaltates and the first examples of trigonal Co".NSF is unstable at room temperature but can be stabilized by the formation of [M(NSF),I2' (M = Co or Ni) by reaction with M(AsF& in liquid SO,. The structure of the Co complex shows that the SF and SN bonds are shorter than in free NSF.14' A short review14' on the chemistry of caged metal ions concentrates on the synthesis stereochemistry and redox kinetics of Co complexes. Extension'42 of earlier work on ternary complexes of Cu'' shows that Co" and to a lesser extent Ni" forms unusually stable complexes when a heteroaromatic base e.g. bis-(2-pyri-dyl)amine and an anionic oxygen donor e.g. pyrocatechol are used the base behaving as a tr-acceptor.The single-crystal magnetic susceptibilities of [Co(Ph,P),X,] (X = C1 or Br) inter~reted'~~ by the angular overlap model show clear v-acceptor character for Ph3P. There has been further debate'44 on the value of the susceptibility of H~CO(NCS)~ the familiar magnetic calibrant. A useful new technique thin-layer spectroelectrochemistry,has been applied to many complexes of quadridentate Schiff bases showing that the Co'/Co" and Col'/Co"' reactions are reversible with E0 values of the former depending on the degree of unsaturation of the ligand whereas for the latter the E* values follow the energy of the CT band.'45 There have been a number of studies on polynuclear complexes including a personal review'46 on their magnetochemistry and the problem of exchange proces- ses involving orbital triplets.The 'H n.m.r. spectra of [M2L3I4+ complexes [M = Co, Ni, Cu2 Zn2 or combinations L = (31)] that where there is no exchange between the two metal atoms the chemical shifts are given by adding the separate contributions from metal atoms and that the presence of a metal ion with very short electronic relaxation time (e.g.Co2+) sharpens usefully the linewidths of protons closer to the metal with longer relaxation time (e.g. Ni2+ Cu"). The X-ray 138 W. L. Darby and L. M. Vallarino Inorg. Chem. 1979 18 2617. 13' (a)W.Burrow and R. Hoppe Angew. Chem. 1979,18,542; (b)W. Burow and R. Hoppe ibid. p. 61. 140 B. Buss P. G. Jones R. Mews M. Noltemeyer and G. M. Sheldrick Angew. Chem. 1979 18 231. 141 A.M. Sargeson Chem. in Britain 1979 15 23. 142 B. E. Fischer and H. Sigel Inorg. Chem. 1979 18 425. 143 J. E. Davies M. Gerloch and D. J. Phillips J.C.S. Dalton 1979 1836. 144 C. J. O'Connor E. Sinn E. J. Cukauskas and B. S. Deaver Inorg. Chim. Acru 1979,32,29;J.-C. G. Bunzli Inorg. Chim. Actu 1979 36 L413. 14' D. F.Rohrbach W. R. Heinemann and E. Deutsch Inorg. Chem. 1979,18,2536. M. Gerloch Progr Inorg. Chem. 1979,26 1. A. Dei D. Gatteschi and E. Piergantili Inorg. Chem. 1979 18 89. F. A. Hart P. Thornton and J. Newbery crystal of [M(hipp),(Hz0),].2H,O (M =Co or Ni hipp =hippurate PhCONHCH2C02) shows that this has a canted linear chain configuration with bridging H,O molecules; the Co complex is a metamagnet. The preparation electronic spectra and solution equilibria of a number of thiophenolate Co" complexes have been de~cribed,'~~ [CO~(SP~)~C~,]~-, including [CO(SP~)~]~- and [CO~(SP~),,]~-; the last of these consists of a co4 tetrahedron with an SPh ligand on each Co and others bridging over each edge of the tetrahedron.The structure of the xylene solvate of [CO~(P~SCH~C~~)~~] contains150a Co6 boat ring but the compound is magnetically dilute at 303 K. The complex orginally formulated as Co,(H,X)- (X)zC104.Hz0 [H2X = (HOC2H4),NH] has been found to be [CO~(H,X)~X~]- (C104), with distinct high-spin Co2+ and low-spin Co3' sites.'" Cobalt(IIr).-The 14N n.m.r. spectrum of [CO(NO,)~]~- has been reassigned.lS2 An X-ray of the nitro-nitrito isomerism in [CO(NH,)~NO~]C~ showed that the thermal nitrito +nitro conversion consists of an intramolecular change probably through a seven-co-ordinate intermediate followed by rearrangement of the crystal and that the photochemical nitro +nitrito rearrangement gives a crystal structure different from the one obtained by synthesis.An interesting reaction of co-ordinated NO,-is shown by the conver~ion'~~ of Ph3P into Ph3P0 and [MoO(S2CNR2),] into [MOO~(S~CNR~)~] by reaction with [Co(saloph)(py)(N02)] [saloph = (32)] the first of these reactions being catalytic when O2is passed through the solution with excess of py present. This is claimed to be the first example of a redox reaction in a metal complex where the process occurs on the ligand rather than the metal. NaHC03 reacts with [{CO(NH~)~},(NH,)OH].~C~ to give [CO,(NH~)~(NH~)(OH)- (C03),].5H20 in which both C032- ions are co-ordinated to the same Co atom.155 Oxygen-bonded unidentate amino-acid (aa) complexes [Co(en),(aa)X]" (X = C1or.Br) have been prepared.'56 A new t.1.c. method gives efficient quick separation on analytical or preparative scales of isomers of Co"' complexes of amino-acids 14* M. M. Morelock M. L. Good L. M. Trefonas D. Karraker L. Maleki H. R. Eichelberger R. Majeste and J. Dodge J. Amer. Chem. SOC.,1979,101,4858. '49 I. G. Dance J. Amer. Chem. SOC., 1979 101,6264. M. Shimoi F. Ebina A. Ouchi Y. Yoshino and T. Takeuchi J.C.S. Chem. Comm. 1979 1132. lS1 J. A. Bertrand E. Fujita and D. G. van Derveer Znorg. Chem. 1979 18 230. K. D. Rose and R.G. Bryant Znorg. Chem. 1979,18 2130. I. Grenthe and E. Nordin Znorg. Chem. 1979,18 1869. lS4 B. S. Tovrog S. E. Diamond and F. Mares J. Amer. Chem. SOC.,1979 101 271. M. R. Churchill G. M. Harris R. A. Lashewycz T. P. Dasgupta and K. Koshy Inorg. Chem. 1979,18 2290. K. B. Nolan and A. A. Soudi J.C.S. Dalton 1979 1419. The Transition Elements 169 peptides or a~0-dyes.l~~ The first optically active [Co(dtc),] complexes have been prepared by the reaction of Na dtc with resolved [Co(edta)]- or other poly- aminocarboxylate complex the resulting configuration being determined stereo- specifically by steric interactions during displacement reactions. 15' As usual there have been many studies of substitution reactions of CO"' complexes.A curious anomaly of apparent reactant association in the anation of cis-[C~(en)~(H~O)~]+ by oxalate in NO3- media was explained 159 by NO3- catalysing the formation of the five-co-ordinate intermediate. In the intramolecular hydrolysis of ~is-[Co(en)~(glyNHR)X]"' (R = H CH2C02Pr or CH2C02- X = H20 or OH- n = 2 or 3) the rate-determining step is (glyNHR) becoming bidentate the process being accelerated by buffers e.g. HP042- or HC03- which also promote the loss of amine rather than of OH-. As usual these reactions proceed 107-1011 times faster than when the amide is not co-ordinated.160 Competition and stereochemical results in a kinetic study161n of the base hydrolysis of resolved ~is-[Co(en)~(NH~)L]~+ [L = Me2S0 or (MeO),PO] show that these have an ion-pairing mechanism; in these examples the triple charge of the cation holds the incoming OH-more strongly than the double charge in such earlier studied cases as [CO(NH~)~C~]~+.The OH- is then close to the five-co-ordinate intermediate as it forms. Similar results were found'616 in [C~(en)~(gly)X]' complexes (X = C1 or Br) in which the carboxylate group of gly can participate. The base hydrolysis of [(NH3)5Co(NCC6H4CN)]3+ to [(NH3)5C~(NHCOC6H4CN)]2+ is followed depending upon pH by rearrange- ment'62 of the carboxamido-group to give e.g. (33). Among interesting studies of redox reactions it was that photochemistry of ColI1 complexes containing RS- or RSe- gave reduction to Co" but R2S complexes gave aquation. The great enhancement of the reduction by Eu2' or Cr2' of penta-ammino Co"' complexes of (02CCH2isn) [isn = (24)] is attrib~ted'~~ to the formation of intermediates with the pyridine r-system as well as carboxyl 0 being co-ordinated to the reducing ion.In reductions by [Fe(CN)s(H20)]3-of [Co(NH3),LI3' [L = (34)] conjugation of L was necessary for electron transfer to occur but if the ligand was sufficiently flexible to allow the metal atoms to approach 15' B. D. Warner and J. I. Legg Znorg. Chem. 1979,18 1839. L. R. Gahan J. G. Hughes M. J. O'Connor and P. J. Oliver Znorg. Chem. 1979 18 933. 159 R. van Eldik and G. M. Harris Znorg. Chem. 1979 18 1997. C. J. Boreham D. A. Buckingham and F. R. Keene J. Amer. Chem. Soc. 1979,101 1409. (a) D. A. Buckingham C. R. Clark and T. W.Lewis Znorg. Chem. 1979,18,1985; (6) C. J. Boreham D. A. Buckingham and C. R. Clark ibid. p. 1990. 16* R. J. Balahura and W. L. Purcell Znorg. Chem. 1979,18,937. 16' V.H. Houlding H. Macke and A. W. Adamson Znorg. Chim. Acta 1979,33 L175. C. A. Radlowski and E. S. Gould Znorg. Chem. 1979,18 1289. F. A. Hart P. Thornton and J. Newbery (34)X = CH2 C2H4 C3H6 C2H2 or CO one another an intramolecular outer-sphere reaction The small range of excited-state electronic spectra has been extended'66 by the study of the 3T1g spectrum of [Co(CN),]'-. This is the first study of a triplet-state Co"' spectrum and the complex's photochemistry was also explained including its greater reactivity than [CO(NH,)6]3' which is excited to a quintet state.Cobalt(II1) complexes feature prominently in a review167 of synthetic dioxygen carriers. The X-ray crystal structure showed'68 that the product of the reaction of tren with [(C0(tren)NH~},0~]~+ was the tetracation (35) with a bridging tren mole- cule. Comparison of the structures of the peroxide complexes [(C0L}~0,].41 [L = (36)] showed that the Co-N(py) bonds in the (36a) complex are shorter and that the CH2NH(CH2) NH( CHZ) NHCH;! (36) a n=2 b; n=3 complex with 0,'-is ~tronger.'~' The detection of v(0-0) at 1137 cm-' in the rR spectrum of [Co(py)X(O,)] [X= (37)] the first observation of this mode in a unidentate O2complex was taken as indicating Co"'-02- bonding.17' A kinetic study 17' of the formation of H202from reactions of acids with pyridine-containing 16' J.-J.Jwo P. L. Gaus and A. Haim J. Amer. Chem. SOC.,1979,101 6189. 166 L. Viaene J. D'Olieslager A. Ceulemans and L. G. Vanquickenborne J. Amer. Chem. Soc. 1979,101 1405. 167 R. D. Jones D. A. Summerville and F. Basolo Chem. Reu. 1979,79,139. M. Zehnder U. Thewalt and S. Fallab Helv. Chim. Actu 1979 62 2099. 17' 169 J. H. Timmons R. H. Niswander A. Clearfield and A. E. Martell Znorg. Chem. 1979,18,2977. T. Szymanski T. W. Cape R. P. Van Duyne and F. Basolo J.C.S.Chem. Comm. 1979 1. 17' J. J. Pignatello and F. R. Jensen J. Amer. Chem. Soc. 1979 101 5929. The Transition Elements (37) (38) solutions of [Co(py)(acacen)02] [acacen = (38)] showed that the complex first dimerized to [{C~(py)(acacen}~O~] which then formed a complex with the acid and this product reacted with pyH’ to give [Co(~y)~(acacen)]+ and H202.Rhodium and Iridium.-The new complexes [{HC(CH2PPh2)3M}2(P3)] (M = Rh or Ir) have been prepared and to have a similar structure (29b) to last year’s Co analogue with a bridging equilateral P3 triangle. The electrochemical reduction of [Rh(diphos),]Cl was to resemble that of the Ir analogue in forming a reactive [Rh(diphos),] complex which can activate C-H bonds and has many potential synthetic applications. X-Ray and neutron diffraction crystal structures revealed174 the geometries of the hydride complexes [Rh2H2{P(OPri),},] (39) and [Rh3H3{P(OMe)3}6](40). Each complex reacts with one molecule of H2 to give R,P\ ,PR3 Rh (40) R=OMe H[Rh2H3{P(OPT^)^}^] and [Rh3H5{P(OMe)3}6] respectively.The hydrogena-tion of nitriles is homogeneously cataly~ed”~ by [RhH(PPr‘,),] and [Rh2H2(N2)- {P(C6H11)3}4] but not by [RhCl(PPh,),]. At higher temperatures the first of these complexes dehydrogenated amines. Contrary to earlier results the X-ray crystal structure and 31P and 15N n.m.r. spectra show that [RhCl(N2)(PPri3)2] contains end-co-ordinated N2 in solid and solution. 176 [Rh{N(SiMe3),}(PPh3),] is the first amidorhodium complex to be made.”’ Dinuclear Rh” carboxylates are still popular objects of study. In [Rh2L2(02CMe)4] [L =py Et2NH CO PF3 P(OMe)3 or P(OPh)3] the Rh-Rh distances of 2.396-2.456 8 were shorter than expected for single bonds; the shortening was attributed to some higher-energy empty orbitals being mixed into the bonding scheme and the authors claim that formal bond order is not a very useful measure of metal-metal interactions.of metal-metal 172 C. Bianchini C. Mealli A. Meli and L. Sacconi Znorg. Chim. Actu 1979 37 L543. 173 J. A. Sofranko R. Eisenberg and J. A. Kampmeier J. Amer. Chem. Soc. 1979,101 1043. 174 R. K. Brown J. M. Williams M. F. Fredrich V. W. Day A. J. Sivak and E. L. Muetterties Proc. Nut. Acad. Sci. U.S.A.,1979,76 2099. 175 T. Yoshida T. Okano and S. Otsuka J.C.S. Chem. Comm. 1979,870. 176 D. L. Thorn.T. H. Tulip and J. A. Ibers. J.C.S. Dalton 1979 2022. 177 (a)G. G. Christoph and Y.-B. Koh,J. Amer. Chem. Soc. 1979,101 1422; (b)Y. B. Koh and G. G. Christoph Inorg. Chem. 1979 18 1122. F.A.Hart P.Thornton and J. Newbery bond lengths in dimeric carboxylates with other dimensions in these molecules showed that this distance correlates closely with the MMO angle but that the QCO and MOC angles are much more responsive to electronic and structural effects. The anomalously high values of the enthalpy of 1:1or 2 1complex formation between various Lewis bases and [Rh2(02CPr)4] were explained'78 by Rh-to-ligand T-bonding. The authors predict that the transition metal will be an electron donor when part of a d5 d7 or d8dimer but an acceptor when part of a do,d',or d3dimer. The many molecular orbital calculations and electronic spectra assignments for these compounds are exemplified by a of [Rh2(H20)2(02CMe)4] in which the single-crystal polarized electronic spectrum was assigned.In other preparative and structural studies 'H n.m.r. spectra showed'*' that the cation previously formulated as [Ir(bipy)3(H20)]3' with unidentate bipy is really [Ir(bipy),LI3' [L = (41)]. An improved preparation of [Rh,(oep),] has been repor- Various hydride-phosphine Rh complexes react with CO and H20 to give bicarbonate Rh"' complexes [RhH2(O2C0H)(PR3),]. For the (R = Pr') complex the HC03- ion is bidentate but hydrogen-bonding couples two molecules; like the formate analogues the complexes reduce CO to CO complexes of Rh'.'82 There has been much photochemistry of Rh"' complexes. The mer-isomer of [Rh(tfa~)~] shows isomerism to the fac-configuration or decomposition or both depending on the solvent's ability to donate hydrogen to the complex.'83 The first comparison has been drawn'84 of the rates of radiative non-radiative and reactive deactivation processes for a d6 complex showing only ligand-field emission in' [Rh(NH3)5X]2+ (X = C1 or Br); rates of substitution in the excited state were 14-15 orders of magnitude greater than those of thermal reactions.The photo-induced oxygenation of [Rh(NH3),(H2O)HI2' to [Rh(NH3)4(H20)(H02)]2' was to proceed by a chain reaction involving [Rh(NH3)4]2'(aq). The varied cis-or truns- configurations of the products of the photoaquation of [Rh(en),XY]"' (X = C1 or Br Y = C1 Br H20,or NH3 n = 1or 2) were explained'" as arising from steric effects acting on the five-co-ordinate intermediate. R. S. Drago S. P. Tanner R.M. Richman and J. R. Long J. Amer. Chem. SOC.,1979,101 2897. "" D. 5. Martin T. R. Webb G. A. Robbins and P. E. Fanwick Znorg. Chem. 1979,18,475. R. D. Gillard R. J. Lancashire and P. A. Williams J.C.S.Dalton 1979 190. la' B. B. Wayland and A. R. Newman J. Amer. Chem. SOC.,1979,101,6472. "* T. Yoshida D. L. Thorn T. Okano J. A. Ibers and S. Otsuka J. Amer. Chem. SOC.,1979 101 4212. ls3 C. Kutal P. A. Grutsch and G. Ferraudi J. Amer. Chem. SOC.,1979 101 6884. la4 M. A. Bergkamp J. Brannon D. Magde R. J. Watts and P. C. Ford J. Amer. Chem. SOC.,1979,101 4549. la5 J. F. Endicott C.-L. Wong T. Inoue and P. Natarjan Znorg. Chem. 1979,18,450. la6 S. F. Clark and J. D. Petersen Inorg. Chem. 1979,18,3394;J. D. Petersen and F. P. Jakse ibid.,p. 1818. The Transition Elements 5 Nickel Palladium and Platinum [Ni(PF2H)4]'87 has been prepared by metal atom-ligand co-condensation having defied synthesis by conventional methods.The X-ray crystal structures of [Ni(S02)(PPh3),] and [Ni(S02),(PPh3),] show that these have near-planar NiS02 units unlike the Pt analogues. 134 Cyclic voltammetry dem~nstrated'~' the formation of [Ni2(triphos),E3]"' species (n = 1-3) (29a). The reaction of white phosphorus with [Ni{(Ph2PC2H4),N}] in THF gives the new yellow-brown diamagnetic complex [Ni((Ph2PC2HJ3N}P4] containing a P4 tetrahedron one atom of which replaces N in co-ordinating to Ni. lg8 Many polynuclear pyrazolyl nitrosyl complexes of Ni have been ~repared,'~~" e.g. (42). These air-stable complexes can be converted into e.g.(43) (44) and the m~noanion'~~' (45). In the [Na(THF),]' salt of (45) the Na is also co-ordinated by the N-N units of two of the bridging ligands. Fe ON-Ni \ N-N Me (42) (43) Me Me MeeMe N-N ON-~f' Me&Me (44) (45) and Co analogues of (42) have been prepared differing in having the boat con- formation for the M2N4 ring whereas the Ni2N4 ring is nearly planar.189c Red K2Ni(S2C202) can be converted into a black form with a stacked structure by various means including improbably treatment with K2Cr207. 190 Transient inter- mediates in the aquation of Ni" polyarnine complexes have been identified;"' among the results was that [Ni(dien),I2' aquates by completely removing one ligand D. C. Staplin and R. W. Parry Znorg.Chem. 1979,18 1473. '" P. Dapporto S. Midollini and L. Sacconi Angew. Chem. 1979,18,469. K. S. Chong S. J. Rettig A. Storr and J. Trotter Cunad.J. Chem. 1979,57,(a)p.3090;(b)p. 3099;(c) p. 3119. A. Gleizes F.Clery M. F. Bruniquel and P. Cassoux Znorg. Chim. Actu 1979,37 19. 19' T. J. Kemp P. Moore and G. R. Quick J.C.S. Dalton 1979 1377. F. A. Hart P. Thornton and J. Newbery in two stages before the second is displaced. The first kinetic studies of five-co-ordinate dS complexes have been on Me3P exchange in [Ni(PMe3)nX(S-nl](n-3)+.(n -3)Y (X = C1 Br I or CN Y = X or BF4) in order to study associative processes in planar d8 complexes. Intermolecular exchange was dissociative but intramolecular exchange might have one of three mechanisms;'92a for X=Y = halide n =4 the anionic halide is involved in the axial-equatorial rearrangement.192b Ni(a~ac)~ reacts with C2N2 at room temperature in CH2C12 to give [Ni(a~ac)~(C~N~)~] which spectroscopic evidence suggests is (46); heating the solution converts this into (47) whose crystal structure was determined.193 Polynuclear Ni" complexes continue to attract attention especially from magnetochemists.The J values in ferromagnetic [Ni2(en)4C12]X2 salts (X = C1 C104 or BPh4) follow the NiClNi angle and the small magnitude of the antiferro- magnetic interactions are explained by the authors' molecular orbital model. lg4The magnetic properties of various [NiLX2] complexes (L= aromatic a-di-imine X = C1 Br or I) that the C1 and some Br complexes were antiferromagnetic dimers and the remaining complexes were monomeric; the structure of [Ni(2,9- Me2phen)12] was determined.Ni2' forms five- or six-co-ordinate complexes with R1N[(CH2) or3NR2R3]2 (L) the former being favoured by longer chain length and methyl substitution at N; for R' =R2=Me R3=H the compound [NiL(OH)]C104 was prepared whose cation was thought to be a five-co-ordinate dimer with two bridging OH groups.'96 Complexes [Nix2] with ligands such as (48) 0-are square-pyramidal dimers when the py ring is not further substituted the 4-or 5-Me derivatives are square-planar monomers and the 6-Me derivative is a tetra- hedral rnon~mer.'~' The preparation and structure of a Ni" complex (49) of maloneamideoximate and 2-ketomaloneamideoximate have been reported.lg8 19' P. F. Meier A. E. Merbach M. Dartiguenave and Y. Dartiguenave (a)Inorg. Chem. 1979,18,610; (6) J.C.S. Chem. Comm. 1979,49. 193 B. Corain A. Del Pra F. Filira and G. Zanotti Inorg. Chem. 1979 18,3523. 19* Y. Journaux and 0.Kahn J.C.S. Dalton 1979 1575. 19' R. T. Butcher C. J. O'Connor and E. Sinn Inorg. Chem. 1979 18 492. M. T. Halfpenny W. Levason C. A. McAuliffe W. E. Hill and F. P. McCullough Inorg. Chim. Acra 1979,32,229. 19' 19* R. P. Cassity and L. T. Taylor J. Co-ordination Chem. 1979,9,71. H. Endres and B. Nuber Z. Naturforsch. 1979 34b,644. The Transition Elements -N LNH2 Higher Oxidation States of Nickel.-The X-ray crystal structure of the diphenyl- glyoximate (dpg) complex [Ni(dpg),I] that this has a stacked polymeric structure consistent with its unidimensional metallic properties; the rR and 12'1 Mossbauer spectra and diffuse X-ray scattering are best explained by the presence of Is- giving Ni the oxidation state 2.2.Similar work on the 1,2-benzo-quinonedioximate (bqd) complex of Nix* shows that this becomes [Ni(bqd)210.018] on recrystallization from benzene which contains traces of 12.Here the stacked planar units are staggered by 68". The authors discuss structural relationships in Ni and Pd compounds of this type concluding that partial oxidation gives a contraction of about 0.02 A in the interplanar spacings with a greater than 103-fold increase in electric conductance in the stacking direction but that the chains of metal atoms may not be the conduction path.200 Addition of S042-stabilizes Nix'' complexes of 14-membered macrocyclic ligands with four N-donors so that these complexes no longer require strongly acid conditions for stability.201 Complexes of Ni"' with the tripeptide from a-amino-isobutyric acid are stable in solutions and show unusual resistance to substitution although they are photosensitive; the stability was associated with the replacement of CH by CMe2.,02 Palladium.-Among new studies of Pd-Pd bonds new examples (50) have been from the reaction of [Pd(PR3),] with HEPR (E=S or Se).The first insertion of SO2 into a metal-metal bond has been with [Pd2(Ph2PCH2PPh2)2C12], which also abstracts S from Ss or MekHCH2d to give S insertion into the Pd-Pd bond.This paper also reports the first oxidation of co-ordinated S2-to SO in which the product remains co-ordinated. Pt analogues are described in both [K2Pd(S03)2].H20 has been prepared204 from K2S03 K2S2O5 and PdCl solu- tions; each Pd is cis-square-planar co-ordinated by two S and two 0atoms and each 199 M. Cowie A. Gleizes G. W. Grynkewich D. W. Kalina M. S. McClure R. P. Scaringe R. C. Teitelbaum S. L. Ruby J. A. Ibers C. R. Kannewurf and T. J. Marks J. Amer. Chem. SOC., 1979,101 2921. 2oo L. D. Brown D. W. Kalina M. S. McClure S. Schultz S. L. Ruby J. A. Ibers C. R. Kannewurf andT. J. Marks J. Amer. Chem. SOC.,1979 101,2937. 201 E. Zeigerson G. Ginzburg N. Schwartz S. Luz and D. Meyerstein J.C.S. Chem. Comm. 1979 241. 202 S. T. Kirksey T. A.Neubecker and D. W. Margerum J. Amer. Chem. SOC.,1979,101 1631. 203 (a)B. Walther B. Messbauer and H. Meyer Inorg. Chim. Actu 1979,37 L525; (6)A. L. Balch L. S. Benner and M. M. Olmstead Inorg. Chem. 1979,18,2996. '04 D. Messer D. Breitinger and W. Haegler Actu Cryst. 1979 B35 815.. F. A. Hart P. Thornton and J. Newbery R'-P- 9' I XI R,P-M-M-PR 1-1-R' I R' (50) M =Pd or Pt; X = S or Se; R R' = alkyl or aryl SO,'-co-ordinates to two Pd atoms through S and one 0,giving a chain structure. Pd" complexes with AH(CH2>,NH(CH2),NH(CH,),(L) have been p~epared.~" For n =2 or 5 [Pd(HL)Clz]C104.Hz0 were prepared in which one N was protonated and two co-ordinated but for n =6-10 [PdLCl]ClO ,were prepared in which L was terdentate with the longest backbone spanning trans-positions.Three forms of [Pd(S2CMe)2] have been prepared;206 one a monosolvate with CS, contains dimeric [Pd2(S2CMe)J units (Pd-Pd 2.738 A) stacked vertically (Pd-Pd 3.257 A); one of the unsolvated forms contains alternating dimer (Pd-Pd 2.754 A) and planar monomer units stacked vertically (Pd-Pd 3.399 A). The rR and Mossbauer spectra of [Pd(bqd)210.s] as monosolvates with toluene or 1,2-C6H4C12 show2" that these contain I;-. Platinum.-The first dinuclear Pt' hydride [Pt,H(d~prn)~]PF (dppm = Ph2PCH2PPh2) has been prepared207 by the reaction of [Pt2H3(dppm)2]PF6 with dppm in CH2C12; the X-ray crystal structure shows a long Pt-Pt bond (2.770 A) and one unidentate and two bridging dppm molecules. An improved synthesis of complexes of ditertiary arsines with PtX (X =Br I or SCN) has been described.208 The crystal structure of [Pt2C12(POF2)2(Et3P)2] (5 1) that F2PO- can be 0 F\II c1 F' \pt/ c1\Pt/ Et,P' 0-4 'PEt unidentate or bridging.The 'H and I3C n.m.r. spectra of basic solutions of [Pt(bipy)J2+ show that all four aromatic rings are equivalent and indicate2'' that substitution of OH- and OH for one bipy is by nucleophilic attack on Pt and not a '05 M. Monoyama and K. Nonoyama Znorg. Chim. Acta 1979,35 231. '06 0. Piovesana C. Bellitto A. Flamini and P. F. Zanazzi Znorg. Chem. 1979,18 2258. M. P. Brown J. R. Fisher L. ManojloviC-Muir,K. W. Muir R. J. Puddephatt M. A. Thomson,and K. R. *O' Seddon J.C.S. Chem. Comm. 1979,931. '08 W.E. Hill D. M. A. Minahan and C. A. McAuliffe Znorg. Chim. Acta 1979,36 L394. '09 S. Neumann D. Schomburg and R. Schmutzler J.C.S. Chem. Comm. 1979 848. 'lo 0.Farver 0.Mansted and G. Nord J. Amer. Chem. Soc. 1979,101,6118. The Transition Elements 177 ligand. The ingenious use of hydroxypropyl cellulose films allowed the studyz1' of the c.d. spectrum of Cs,[Pt(CN),].H,O clarifying some of the assignments. There have again been many studies of Pt" complexes of biological ligands. The X-ray crystal structure of ~is-[Pt(NH~)~(guanosine)~]~+ and the'H n.m.r. spectrum of [Pt(Me,en)(g~anosine)~]~+show that each is chiral and that square-planar complexes can show chirality when two large planar ligands occupy cis-positions and are too bulky to rotate about the M-L bond.212 The reaction of theophylline (L) with [PtC1,I2-gives213a[PtCI,L]-in which L co-ordinates through the tertiary imidazole N.The structure of [Naz(5'-impH)2.16HzO]o.14[Na2{(NH3)2Pt(5-imp)z}.15-16H20]o.86 also shows co-ordination through the tertiary imidazole N in inosine monophosphate and the authors conclude from this and earlier work that the structures adopted by complexes of this type depend on a balance of the co-ordination requirements of Pt and crystal packing Complexes of 7,9-dimethylhypoxanthine with Pt" and dien or en provide the first examples of purine N-Pt complexes.214 Stacked complexes are another active area. There are two reportsZl5of the X-ray crystal structure of [Pt(en)2]2+.[Pt(en)212]2+.4C104. One215asuggests that the oxida-tion state differences between the two types of Pt were not as great as in the C1or Br analogues and the report with a different space group found alternating Pt-I distances (2.791 3.036 A) and reported all Pt to be equivalent.The neutron diffraction crystal structure of Rb2[Pt(CN),]Cl0,,.3H20 at 110 K shows216a shorten-ing of Pt-Pt of 0.2 % over the distance at 298 K and less dimerization within the chain although the conductance decreases whereas less dimerization usually gives greater conductance. This was explained by a transition to insulator character at low temperature. The authors concluded that as the radius of the counter-cation increased there was a greater likelihood of dimerization that shorter Pt-Pt dis-tances give less dimerization and that the Pt-Pt distance depended on the degree of oxidation.[Cs2Pt(CN)4](N3)o.z5.0.5Hz0 is the first azido partially oxidized tetra-cyanoplatinate and has a Pt-Pt distance of 2.877A in the usual polymeric ~tructure.~''Further details have been published218"of the 'platinum blue' formed with a -pyridone [L (52)] [Pt,(NH3)8L4]5'.5N03-.H20. The linear tetramer cation (53) has Pt-Pt bonds of 2.775 (outer) and 2.877 A (inner) and PtPtPt angles of H I N ~ H3N H3N NH3 NH3 0-A OF-\ / \Pt/ \/ Pt -\< Pt- Pt-/\ N /\ H3N H3N /\ NH3 NH3 N O/ 0 -/ 0'0 (53) 'I1 F. D. Saeva G. R. Olin R. F. Ziolo and P. Day J. Amer. Chem. SOC.,1979 101 5419. "'R. E. Cramer and P. L. Dahlstrom J.Amer. Chem. SOC.,1979,101,3679. *13 (a)E. H. Griffith and E. L. Amma J.C.S. Chem. Comm. 1979 322; (b)T. J. Kistenmacher C. C. Chiang P. Chalilpoyil and L. G. Marzilli J. Amer. Chem. SOC., 1979 101 1143. '14 T. J. Kistenmacher K. Wilkowski B. de Castro C. C. Chiang and L. G. Marzilli Biochem. Biophys.Res. Comm. 1979,91,1521. '15 (a)N. Matsumoto M. Yamashita S. Kida and I. Ueda Acra Cryst. 1979 B35 1458; (b)H. Endres H. J. Keller R. Martin H. N. Gung and U. Traeger ibid. p.1885. 'I6 R. K. Brown and J. M. Williams Inorg. Chem. 1979 18 1922. '17 R. K. Brown D. A. Vidusek and J. M. Williams Znorg. Chem. 1979,18 801. *18 (a)J. K. Barton D. J. Szalda H. N. Rabinovitz J. V. Waszczak and S. J. Lippard J. Amer. Chem. SOC. 1979 101 1434; (b)J. K. Barton C. Caravanna and S.J. Lippard ibid. p. 7269. 178 F.A. Hart P.Thornton and J. Newbery 165". The magnetic moment of 1.81pB per tetramer shows one unpaired electron and an oxidation state of 2.25; the e.s.r. spectrum shows that this electron is in an orbital in the Pt chain direction. The blue Pt amide complexes all have mixed- valency oligomeric structures and bridging amidates. In another report2lSb a general similarity of solution properties was found but gel electrophoresis suggested different lengths of oligomer chain. New Pt" squarate complexes K2[PtX2] (X = c404) and K1.6[PtX2] have been ~repared;~" the latter has metallic electric conductance. 6 Copper Silver and Gold Copper(0) and Copper(I).-Cryophotochemical and X,-SW calculations on Cu2 show that unlike Ag, which is almost purely s-bonded it has a small d-contribution to the bonding.,,' The co-ordination chemistry of Cu' ions generated from the metal by laser ionization has been studied22' by ion cyclotron resonance spec- troscopy; only a 2 1complex was found with NH but at least 3 1with MeCN.Many poly(pyrazoly1)borate-Cu' complexes have been prepared and appear to be four- or three-co-ordinate.222 Equilibrium constants for the binding of unidentate ligands (R3P RNC CO) with Cu' compounds of uninegative macrocyclic quadri- dentates are highest when the macrocycle is almost planar but flexible.223 More cubane complexes have been described. The first Cu-S cube has been in [(Ph3PCu),C1(S3WO)] (54) prepared from [CU(H,O)~C~,] Ph3P and Cs2WOS3.Another [W0S3l2- complex [((C,H,),PCU}~(WOS~)~] has a structure (55) resembling one found last year for [WS4]'- with Ag and Au.*,~ Contrary to P(C7H7)3 / s-cu-s (C7H7)3P<u-i-S~W%0 'I I Ph3P-0=!7W-I -S-~?U-P(C7H7)3 Cl-cu s-cu-s earlier indications from far-i.r. spectra the X-ray crystal structure of [Ph3AsCuII4 shows that this molecule has a cubane rather than step structure.226 Unlike most other Cu' halide-phosphine complexes [{(C6H1 1)3P}CuCl] is not a tetramer but a dimer with three-co-ordinate Cu as this structure reduces phosphine-C1 contacts and allows more room for bulky cyclohexyl groups.227 '19 H. Toftlund J.C.S. Chem. Comm. 1979,837. 220 G. A. Ozin H. Huber D. McIntosh S. Mitchell J. G. Norman and L. Noodleman J.Amer.Chem. SOC. 1979,101,3504. 221 R. C. Burnier T. J. Carlin W. D. Reents R. B. Cody R. K. Lengel and B. S. Freiser J. Amer. Chem. SOC.,1979 101,7127. "'0.M. Abu Salah M. I. Bruce and J. D. Walsh Austral. J. Chem. 1979,32 1209. 223 R. R. Gagne J. L. Allison and D. M. Ingle Inorg. Chem. 1979,18 2767. 224 A. Muller T. K. Hwang and H. Bogge Angew. Chem. 1979,18 628. '"R. Doherty C. R. Hubbard A. D. Mighell A. R. Siedle and J. Stewart Inorg. Chem. 1979,18,2291. 226 M. R. Churchill and W. J. Youngs Inorg. Chem. 1979,18 1133. 227 M. R. Churchill and F. J. Rotella Inorg. Chem. 1979 18 166. The Transition Elements 179 Interest in mixed oxidation state and redox studies continues; some results are described in the section on Cu proteins. CuCl reacts with hydrazine under various conditions to give228 [(N2H4)CuC1] [(N2H&Cu3C16] [(N2H5)2CuCla].2H20 or [(N,H5)CuC13].The last three of these complexes contain co-ordinated [N2H5]'; the second has two Cu' and one Cu" and the last has the structure of a ladder-like polymer with bridging C1 atoms. The T1' salt of [CU~~(SCM~~CO~)~~CI]'-has a similar struct~re~~~ to the known penicillamine and cysteamine analogues having C1 at the centre of a cube of Cu' which is surrounded by an icosahedron of Satoms and an octahedron of Cu2'. Each Cu' is bonded to three Satoms and the more distant C1 each Cu2' to two S and two 0 atoms. Copper(rI).-The preference for tetragonal elongation over compression in Jahn- Teller distorted Cu" octahedral complexes is attributed2,'" to configurational inter- action effects with excited states.A review23ob of six-co-ordinate Cu" complexes having gll< gl draws attention to the limitation of this criterion for establishing tetragonal compression. The polarized single-crystal electronic spectrum of the [PhC2H4NH2Me]' salt of [CUC~~]~-, known to be strictly planar with no axial ligands shows unusual vibra- tional fine structure; an angular overlap model shows the d,2 to be the lowest energy d-orbital at -5000 cm-' lower energy than anticipated owing to configuration interaction with 4s. It was also found that the CuCl bond may be -0.10 A longer in the excited states in which there may be a distortion towards tetrahedral sym- met~y.~~~ A convenient of Cu(0Me)X compounds (X = diketonate RCO, PhO etc.) uses the reaction of CuY (Y = NO or c104) with MeOH HX and piperazine.The X-ray crystal structure of the red and the blue-violet forms of [CU(N,N-E~~~~)~]~'.(C~O~)~ shows that both forms are square-planar the difference in Dq arising from different chelate ring conformations; the different conformations were also detected by solid-state n.m.r. Another application233b of solid-state n.m.r. has been to derive the Cu-H distances in trans-[Cu(DL- alanine)2].H,0 and to determine the proton isotropic coupling constants which were not resolved in e.s.r. spectra; these show spin delocalization from the dx2-y2 orbital through the a-bond and the technique may be very valuable in the future. [C~(2,4-Me~py)(NC0)~] reacts with 3,5-dimethylpyrazole to give (56),first recog- nized as curicw by its unusual i.r.There have been many studies of Cu" complexes in solution often using biological ligands beside those (to be described later) specifically aimed at elucidating the nature of Cu proteins. The mechanism of the catalase-like disproportionation of HzOZ by aqueous Cu" was studiedz3' by measuring 0,evolution with an O2-sensitive electrode with the conclusion that co-ordinated H202 becomes OOH- and then 228 D. B. Brown J. A. Donner J. W. Hall S. R. Wilson R. B. Wilson D. J. Hodgson and W. E. Hatfield Inorg. Chem. 1979 18 2635. 229 R. J. M. W. L. Birker Inorg. Chem. 1979,18,3502. 230 (a)H. Yarnatera Acta Chem. Scand. 1979 A33 107; (b)I. Bertini D. Gatteschi and A. Scozzafava Co-ordination Chem.Rev. 1979,29,67. 231 M. A. Hitchrnan and P. J. Cassidy Inorg. Chem. 1979 18 1745. 232 M. A. Yampol'skaya G. S. Matuzenko and A. V. Ablov Russ. J. Inorg. Chem. 1979,24,463. 233 (a) I. Grenthe P. Paoletti M. Sandstrorn and S. Glikberg Inorg. Chem. 1979 18 2687; (b) T. Sandreczki D. Onercin and R. W. Kreilick J. Amer. Chem. SOC. 1979,101 2930. 234 F. Valach J. Kohout M. Dunaj-JurZo M. Hvastijovh and J. Gaio J.C.S. Dalton 1979 1867. 235 H. Sigel K. Wyss B. E. Fischer and B. Prijs Knorg. Chem. 1979 18 1354. F.A. Hart P. Thornton and J. Newbery another H202 co-ordinates and reacts with the OOH- to form 02,H20,and OH-. Cu(bipy)2' reacts even faster than expected from ,the great stability of this ion's complexes with two 0-donors.Linewidth studies on 'H n.m.r. spectra of Cull complexes with purine bases nucleosides and nucleotides show that Cu can be chelated by the purine N and an exocyclic NH or NH group but not by an exocyclic and the same technique for Cu"-Gly-Gly-His solutions revealed2366 a pH dependence of the linewidth due to incomplete complex formation so the authors warn that care needs to be taken in interpreting such experiments. Various potentiometric of complex formation between Cu2' and thiodialkanoates clarified confusion over which species were formed and showed that thiodibutanoate was unidentate but that the other ligands were more likely to be bidentate and protonation gave bidentate or terdentate character. Complex (57) a model for metallohydrolase has -106-fold faster hydrolysis of the amide group than when the Cu is absent probably because Cu is above the C=O bond instead of co-ordinated by it the likely mechanism being nucleophilic addition of the metal-bound OH-to the C=O bond.238 From a kinetic study of the reaction (58) m,n = 2 or 3 of Cu2+ with linear or cyclic polythioethers it was concluded239 that the entropy terms associated with co-ordination of the third and later S atoms were responsible for the greater stability constants found for complexes with macrocyclic ligands; thioether donors lack the hydrogen-bonding propensity that complicates similar studies of polyamine complexes.Cu" complexes with the dinegative macrocycles (58)showed '"(a)G. V. Fazakerley G. E. Jackson M. A. Phillips and J.C. van Niekerk Inorg. Chim. Acru 1979,35 151;(b)Y.Kuroda and H. Aiba J. Amer. Chem. SOC.,1979 101,6837. 237 F. J. C. Rossotti and R. J. Whewell J.C.S. Dalton 1979 257. 238 J. T.Groves and R. M. Dias J. Amer. Chem. Soc. 1979 101 1033. 239 L. D. Diaddario L. L. Zimmer T. E. Jones L. S. W. L. Sokol R. B. Cruz E. L. Yee L. A. Ochrymowycz and D. B. Rorabacher J. Amer. Chem. soc. 1979,101,3511. The Transition Elements 181 unusual electronic and e.s.r. spectra inability to accept fifth or sixth ligands and resistance to Substitution of electron-withdrawing (CN NOz) groups into pyrrole rings of Cu porphyrin complexes has little effect on electro-oxidation but more on electroreduction indicating that oxidation occurs at N atoms and reduction on the ~-system.~~l Polynuclear Copper(I1) Complexes.-Much valuable structural and magnetic work has again appeared.Polarized neutron scattering of [(H,O)(bipy)Cu(p-OH),Cu(bipy)(S04)].4H20 showed spin density on the bridging OH groups and not in the space between the Cu atoms confirming our ideas about superexchange proce~ses.'~'The singlet-triplet transition of [CU~(D,O)~(O~CD,)~] was by neutron inelastic scattering at a constant value of 298 cm-' over the 10-300 K temperature range. This is an important direct measurement which should be extended to other systems. The X-ray crystal structure of ferromagnetic (J = 35 cm-') [Cu2C1z{HB(pz)3}z] [HB(pz)=(5)] shows that this has two bridging C1 atoms; the writers reviewz43 magnetic results on C1-bridged Cur* dimers.The preparation structure and magnetism of [Cu2(0CHzPh)z(dbm)z] [dbm =(PhCO),CH] show that the antiferro- magnetism (J= -324 cm-l) is much larger than that of analogous OH- complexes probably because there is greater electron density on the bridging 0 atoms.244 The clod- salt of [Cuz(MezNC3H6NHCzH40)2(MeOH)z]z~ (59) has a magnetic moment MeOH greater than expected from the CuOCu angle of 103.6",possibly because the MeOH is closer to Cu than is the fifth ligand in other dimer~.~~' The rubeanate derivative [Cu2{SzCz(NCzH40H)2)z(HzO)(S04)].H20 has the large J value of -523 cm-' explained by particularly good overlap of ligand orbitals with dX2-,,2 on Cu; the compound is compared with the previously reported isomer with both HzO co- ~rdinated.'~~ A dihedral angle of 147.5' was between the CuOzN2 planes of [~U~(~~)~(~~H~~NH~)~]~~.~~~~~~ and led to an extension of molecular orbital treatment of magnetic exchange to complexes having dihedral angles other than 180" but for this complex an unusually high proportion of impurity had to be 240 H.Okawa and D. H. Busch Inorg. Chem. 1979,18 1555. 241 A. Giraudeau H. J. Callot and M. Gross Znorg. Chem. 1979,18 201. 242 H. U. Giidel A. Stebler and A. Furrer Znorg. Chem. 1979 18 1021. 243 S. G. N. Roundhill D. M. Roundhill D. R. Bloomquist C. Landee R. D. Willett D. M. Dooley and H. B. Gray Znorg. Chem. 1979,18 831. 244 H. E. Le May D. J. Hodgson P. Pruettiangkura and L. J. Theriot J.C.S. Dalton 1979 781. 245 N. Matsumoto S. Kida and I.Ueda J. Co-ordination Chem. 1979,9 133. 246 C. Chauvel J. J. Girerd Y. Jeannin 0.Kahn and G. Lavigne Znasg. Chem. 1979 18 3015. 247 M. F. Charlot S. Jeannin Y. Jeannin 0.Kahn J. Lucrece-Abaul and J. Martin-Frere,Znorg. Chem. 1979,18 1675. F.A.Hart P.Thornton and J. Newbery invoked to obtain a good fit to the data. Changing the metal atom M (Cu Ni Co or Mn) in the dinuclear complex (60)gave minor changes in structure; the CuOM angles (60) were the most important parameter in interpreting the magnetism but the two values should not be averaged the angle associated with the shorter superexchange path carrying more The authors describe calculations for dimers with unequal spins or inequivalent g values. Many papers are less concerned than these with the magnetochemical principles of Cu" but report interesting new structures.The N604 macrocycle (61) (L) (61) with forms [CU~L(N~)~]+.CIO~- a folded ligand having only N atoms co-ordinating and with an azide bridge giving weak antiferromagnetism in contrast to [CU~L(OH>(C~O~)~].~H~O which is more antiferromagnetic and may have an OH bridge.249 Spectroscopic and magnetic properties favour a dimeric structure for the complex between uridine and Cu" and OH bridges in (X= 2'-deoxyg~anosine).~~'~ [(HZO)~CU((OH)~CUX}~].~H~O The latter is claimed to be the first isolated metal complex with a DNA residue and may also have bridging by the deoxyribose unit. Despite the presence of carboxylate ligands [CU~(M~~NC~H~O)~(CICH~CO~)~] adopts the cubane structure usually found in aminoethanolate Cu" complexes.251 Two different clusters occur in a complex of (MezNCH2CH2N=CPhCMe=NO)-(X) 248 C.J. O'Connor D. P. Freyberg and E. Sinn Inorg. Chem. 1979,18,1077. 249 M. G.B. Drew M. McCann and S. M. Nelson J.C.S. Chem. Comm. 1979,481. (a) P. Chalilpoyil and L. G. Marzilli Inorg. Chem. 1979,18,2328;(6)H. C.Nelson and J. F. Villa ibid. p. 1725. 251 U. Turpeinen M. Ahlgrin and R. Hamalainen Acta. Chem. Scand. 1979,A33,593. The Transition Elements 183 [CU~X~(C~O~)~].[CU~X~(M~OH)~]~+.~C~O~- (62); the oxime group acts as the bridg- ing unit and the complex is diamagneti~.~’~ (62) L = MeOH or C104 The X-ray crystal structure of Ag[C~~(phthalate)~(OH)]SH~O is a complex polymeric arrangement in which half the phthalate ions use all four 0 atoms to co-ordinate to Cu the first example of phthalate doing so these anions also interact with the Ag through a C-C bond.253a Another polymeric structure was for the Cu” complex of L-methionylglycinate each Cu being co-ordinated by a carboxyl0 and the two N atoms from one ligand the other carboxyl0 from a second and a peptide 0 from a third to give a square-pyramidal configuration.In water or KBr discs the last of these Cu-0 bonds is replaced by H20or Br. [C~(pyz)~(ClO~)~] has a polymeric sheet structure with pyrazine bridges canting of the pyz ring by 66” to the plane of the sheet allowing exchange to occur through the ligand’s v-Copper Proteins.-The blue (type I) proteins have attracted most attention in this very active area.A review255 of n.m.r. studies includes discussion of pK values and conformational problems. Studies of reduction potentials at various temperatures gave entropy and enthalpy values which were interpreted in terms of probable solvation changes and correlated with earlier kinetic results with inorganic reagent^.^'^ Kinetic studies of the oxidation of reduced pla~tocyanin~~~~ and az~rin~~~’ by [Fe(CN)6]3- (Co(phen),13’ and [C0(4,7-dpsphen)~]~- [dpsphen = (63)] indicated that the oxidants acted at different sites which for the first two were (63) 252 R. J. Butcher C. J. O’Connor and E. Sinn Znorg. Chem. 1979,18 1913. 253 (a)M. Biagini Cingi A. M. Manotti Lanfredi A. Tiripicchio and M. Tiripichio Camellini.Acta Cryst. 1979 B35,312; (b)J. Dehand J. Jordanov,F. Keck A. Mosset J. J. Bonnet and J. Galy Znorg. Chem. 1979,18,1543. 254 J. Darriet M. S. Haddad E. N. Duesler and D. N. Hendrickson Znorg. Chem. 1979,18,2679. 255 E. L. Ulrich and J. L. Markley Co-ordination Chem. Rev. 1978 27 109. 256 N. Sailasuta F. C. Anson and H. B. Gray J. Amer. Chem. SOC.,1979 101,455. 257 (a)A. G. Lappin. M. G. Segal D. C. Weatherburn and A. G. Sykes J. Amer. Chem. SOC.,1979,101 2297; (b)A. G. Lappin M. G. Segal D. C. Weatherburn,R. A. Henderson and A. G. Sykes ibid. p. 2302. F. A. Hart P.Thornton and J. Newbery near two un-co-ordinated histidine groups; for azurin protein-complex association constants could be measured as this process occurred before electron transfer.Absorption fluorescence and c.d. spectra and competitive binding studies show that Mn Co and Ni can all replace Cu in az~rin.~~* The authors also assign the charge-transfer bands as various S +Cu transitions involving cysteine or methionine units. A thorough spectroscopic investigation259" of ceruloplasmin its N3- and SCN- complexes and its ascorbate-modified form in which type I Cu is depleted show that type I Cu is co-ordinated by two histidine one cysteine and one methionine ligand that changes occur on this Cu on reaction with N3- or SCN- that the type I1 Cu have four N-donors tetragonally placed and that type I11 sites are not tetrahedral. Similar on two forms of laccase show that the type I Cu atoms are in a DZddistorted tetragonal geometry that binding F-at the type I1 perturbs the c.d.spectrum of type I that type I1 and I11 sites are not tetrahedral and that there are many spectral changes on reaction with NO. Many Cu complexes with S-donors have been used as model complexes for blue Cu proteins. Compounds containing CuS groups gave a low value for A,,,as in the proteins and this was also found when tetragonal complexes had some tetrahedral distortion.260 The new ligand (64) (L) designed261 to encourage the often reluctant formation of Cu-thioether bonds forms a [CuLIBF complex which is easily oxidized but [CuL(H20)(C104)]C104 is stable and reacts with RS- to give a strong blue colouration. The X-p.e. spectra of (65)and its Cu" complex suggest that the /\ appearance of the S, peak at' 168 eV in blue proteins is not genuine but Cu- catalysed radiation damage which gives oxidation of the ligand.262 Cur and Cu" complexes of (5) of the type [L3CuSR] have been indicating again that the 600 nm absorption of the blue proteins is a cysteinyl S +Cu transition and that the resonance Raman bands at 350-450 and -270cm-' are Cu-N and Cu-S vibrations but the complex did not show low All values; similar studies were made on Co analogues.263b The existence of an imidazolate bridge between Cu2+ and Zn2' in bovine eryth- rocyte superoxide dismutase (BESOD) prompted further on imidazolate D.L. Tennent and D. R. McMillin J. Amer. Chem. SOC., 1979 101 2307. 259 (a)J. H. Dawson D. M. Dooley R. Clark P. J. Stephens and H. B. Gray J. Amer. Chem.SOC.,1979 101 5046; (6)D. M. Dooley J. Rawlings J. H. Dawson P. J. Stephens L.-E. AndrCasson B. G. Malmstrom and H. B. Gray ibid.,p. 5038. 260 U. Sakaguchi and A. W. Addison J.C.S. Dalton 1979 600. 261 J. V. Dagdigian and C. A. Reed Znorg. Chem. 1979 18,2623. 262 M. Thompson J. Whelan D. J. Zamon B. Bosnich E. I. Solomon and H. B. Gray J. Amer. Chem. SOC. 1979,101,4193. 263 (a)J. S. Thompson T. J. Marks and J. A. Ibers J. Amer. Chem. SOC.,1979 101 4180; (b)J. S. Thompson T. Sorrell T. J. Marks and J. A. Ibers ibid. p. 4193. 264 M. S. Haddad E. N. Duesler and D. N. Hendrickson Znorg. Chem. 1979 18 141. The Transition Elements and bi-imidazolate (biim) complexes such as [C~~(Me,dien)~(biim)]~', in which biim bridges from the equatorial site of one square-pyramidal Cu to the axial site of another and there is no magnetic interaction between the two Cu atoms.The authors discuss the magnetism of imidazolate-bridged complexes and draw attention to the importance of the orientation of the imidazolate plane to the Cu co-ordination planes and of the nature of the Cu ground state. The dinucIear complex [C~~L(irnH)~(irn)](ClO,)~ [imH = imidazole L = (66)]is also intended as a model for BESOD. The cryptate co-ordinates both Cu atoms which are also bridged by im and it holds the Cu atoms in place when the imidazolate bridge is broken as occurs in the enzyme.26s The e.p.r. and electronic spectra of various haemocyanins indicate that oxy- haemocyanin contains two Cu" atoms bridged by both 022-and a protein group; the 022-+Cu bands are strong features in the visible spectrum.266 Half-met haemocy- anins have been prepared by the addition of various anions and contain one Cu" and one Cux.267 The met apo-form has also been prepared containing one Cu" only.It was concluded that the anion in the half-met haemocyanins bridges the Cu atoms in addition to the protein bridge. Some of these half-met complexes have such mixed-valence properties as intervalence electronic spectral absorptions and de- localized e.p.r. signals.267 The syntheses of (67) and many similar complexes have been reported. This complex has two three-co-ordinate Cur atoms despite the Me 265 P. K. Coughlin J. C. Dewan S. J. Lippard E. Watanabe and J.-M. Lehn J. Amer. Chem. Soc.1979 101 265. 266 N. C. Eickman R. S. Himmelwright and E. I. Solmon Proc. Nat. Acad. Sci. U.S.A. 1979,76,2094. "'R. S. Himmelwright N. C. Eickman and E. I. Solomon J. Amer. Chem. Soc. 1979,101 1576. 186 F. A. Hart P. Thornton and J. Newbery availability of pyridyl nitrogens. The redox potentials are comparable to those of dinuclear Cu proteins but unlike haemocyanin they do not react with C0.268 Silver.-Silver is proving to have remarkable individuality in many aspects of its chemistry. The Ag' complex of the crown ligand (68) can be photochemically reduced to the Ago complex which does not decompose to free metal; the large size of the Ag atom gives a much higher formation constant (-lo2') than for Ag' (-7 x 107).269The [WS,]'- ligand shows further versatility in bridging two Ag' atoms in [(Ph3P)3Ag2(WS4)] (69),whose X-ray crystal structure shows one tetrahedral and pi '07 HN NH one trigonal Ag'.270 Reaction of 2,6-diacetylpyridine with 3,3'-diaminodipropyl- amine in the presence of Ag' givesZ7l not the expected cyclic quadridentate ligand but an octadentate macrocycle which co-ordinates two Ag' atoms each bonded to four nitrogens in an irregular geometry (70).The crystal structure of [Ag(NO,)(l-Mecytosine)] shows that this is a polymer of dimeric units and the authors believe272 that the strong Ag' DNA complex may involve two Ag' ions for each base pair. The crystal structure of [(Ph3PAg)4(naphthalene-l,8-dicarboxylate),].2C6H6 shows that this contains a (Ph3PAg) core surrounded by eight 0 atoms; molecular weight and 31 P n.m.r.spectra show that this and other phosphine analogues are tetrameric in solution with all metal sites equivalent and [LAg2(0,CMe),] (L = bidentate 268 R. R. Gagnt R. P. Kreh and J. A. Dodge J. Amer. Chem. Soc. 1979,101,6917. 269 R. Humphry-Baker M. Gratzel P. Tundo and E. Pelizzetti Angew. Chem. 1979,18,630. 270 A. Muller H. Bogge and E. Koniger-Ahlborn 2.Nururforsch. 1979 34b 1698 271 M. G. B. Drew S. G. McFall S. M. Nelson and C. P. Waters J. Chem. Res. (S) 1979 16. 272 T. J. Kistenmacher,M. Rossi and L. G. Marzilli Inorg. Chem. 1979 18 240. The Transition Elements 187 diphosphine) probably have acetate and phosphine bridging to give three-co- ordinate silver.273 Gold.-Pyrazole and other azoles (HX) form Au' compounds AuX many of which were thought to be cyclic trimers [Ph3PAuX] [Ph3PAuXAuPPh3]+ and the mixed- valence [Au~I~X~].~~~ The preparation and X-ray crystal structure of the [Au8(PPh3)J2+ cation has been reported in the alizarin~ulphonate~~~" and (PF6)2756 salts and is best described as derived from the [AU~~(PR,)~]~+ structure by removal of a basal triangle and fitting the central Au with a PPh ligand (71).The structure of Ph,P PPh AuOCl includes O6hexagons with Au co-ordinated by C1 at the centres of the sides; the hexagons are linked to give Au202 squares so that Au"' has its usual square- planar co-ordination. 273 A. M. F. J. van der Ploeg G. van Koten and A. L. Spek Znorg. Chem. 1979,18 1052. 274 G.Minghetti G. Banditelli and F. Bonati Znorg. Chem. 1979 18,658. *'' (a)M. Manassero L. Naldini and M. Sansoni J.C.S. Chem. Comm. 1979,385; (b)F. A. Vollenbroek W. P. Bosman J. J. Bour J. H. Noordik and P. T. Beurskens ibid. p. 387. 276 P. G. Jones H. Rumpel E. Schwarzmann and G. M. Sheldrick Acru Cryst. 1979 B352380.

ISSN:0260-1818    

DOI:10.1039/IC9797600148

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

4 Organometallic Chemistry ByA. J. DEEMING Department of Chemistry University College London London WClH OAJ J. EVANS Department of Chemistry The University Southampton SO9 5NH Introduction The organization of this Section parallels that of last year. Volume 17of Advances in Orgunometullic Chemistry has been devoted to catalysis and organic syntheses. The following topics are included hydroformylation," the Fischer-Tropsch reaction,b nickel-catalysed olefin oligomerization,' palladium-catalysed reactions of butadiene and isoprene,d organonickels in organic synthesis,' rhodium- and iridium-catalysed methanol carbonylation,f codimerization of ethylene and butadiene,g hydro- genation,h hydrosilation,' and olefin metathesis.' Volume I1 of Transition Metal Organometallics in Organic Synthesis has chapters on transition-metal alkynes and derived clusters on arene complexes and on oxidation reduction and rearrange- ment of organo-complexes.k Reviews have also appeared on [Fe(C0)4],' direct electrochemical synthesis of organometallic compounds,m metallated nitrogen" and sulphur" donor ligands chiral complexes and asymmetric catalysis,' alkylidene complexes of niobium and tantalum,' mechanisms of elimination from osmium hydrides and alkyls,' free-radical reaction pathways' sandwich complexes with a R.L. Pruett Adv. Organometallic Chem. 1979,17 1. C. Masters 61. B. Bogdanovic 105. J. Tsuji 164. G. P. Chiusoli and G. Salerno 195. 'D. Forster 255. A. C. L. Su,269. B. R. James 319 J. L. Speier 407.N. Calderon J. P. Lawrence and E. A. Ofstead 449. ' 'Transition Metal Organometallin in Organic Synthesis' ed. H. Alper Academic Press 1978 Vol. 11. ' M. Poliakoff Chem. SOC. Rev. 1978,41,527. D. G.Tuck PureAppl. Chem. 1979,51 2005. I. Omae Chem. Rev. 1979,79,287. I. Omae Coordination Chem. Rev. 1979 28,97. H. Brunner Accounts Chem. Res. 1979,12,250. R. R. Schrock Accounts Chem. Res. 1979,12,98. ' J. R. Norton Accounts Chem. Res. 1979,12 139. J. Halpern Pure Appl. Chem. 1979 51 2171. A. J. Deeming and J. Evans boron-containing ligands,' and catalysis by iridium" and palladium" compounds. Transition-metal hydrides" and specifically cluster hydrides" have been reviewed and other aspects of clusters have also been dealt with tetracobalt clusters contain- ing heteroatoms,Y osmium carbonyl clusters,' large cluster anions,"" the relation between clusters and surfaces,ab and the binding of alkenes to Co Ni and Cu naked metal clusters."' Clusters are also included in a discussion of the mechanistic features of CO hydrogenation."d

ISSN:0260-1818    

DOI:10.1039/IC9797600189

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

A. J. Deeming and J. Evans PartI Alkyls Aryls Carbonyls Cyanides Carbenes and Carbynes By J. Evans 1 Metal Carbonyls Mononuclear Carbony1s.-An empirical method for estimating CO factored force and interaction constants has been presented.' Force constants for example are estimated from equation (l),where kd is the force constant of an isolated M-CO kco= kd +CLcLe (1) fragment with the right d" configuration and E~~ are ligand effect constants of adding a ligand at an angle 8. Combined with interaction constant estimations calculated vco frequencies were within 4 cm-' of experimental values. Hartree-Fock-Slater calculations on [Ni(C0)3L] derivatives indicate that vco is influenced by both the extent of ?r-back-bonding and steric interactions.' The latter effect makes vco an unreliable estimation of back-bonding.X-Ray p.e. spectra of the core orbitals of mononuclear carbonyls and nitrosyls have been re~orded.~ The ionization energies obtained suggest that CO competes very weakly for T-electron density with NO. Hydride ligands have an electron-withdrawing effect in carbonyl hydride~.~ Charges on the hydrogen ligands were estimated at -0.03 -0.08 and -0.75 for [H2Fe(C0)4] [HMn(C0)5] and [HCO(CO)~] respectively. Absorption and emission spectra of [M(C0)6] and [M(CO)5py] derivatives (M = Mo or W) have been measured in matrices at 12 K.' The hexacarbonyl emissions were assigned as either a 'TI +'A, or a 'TZg +'A1 transition. M.c.d. spectra R. N. Grimes Coordination Chem. Rev. 1979,28,47. R.H. Crabtree Accounts Chem. Res. 1979,12,331. R. F. Heck Accounts Chem. Res. 1979,12 146. R. Bau R. G. Teller S. W. Kirtley and T. F. Keotzle Accounts Chem. Res. 1979 12 176. A. P. Humphries and H. D. Kaesz Progr. Znorg. Chem. 1979,25 145. L. Marko Gazzetta 1979,109,247. J. Lewis and B. F. G. Johnson Gazzetta 1979,109 271. aa P. Chini Gazzetta 1979,109 225. ab E.L. Muetterties T. N. Rodin E. Band C. F. Brucker,and W. R. Pretzer Chem. Rev. 1979,79,91. G. A.Ozin Coordination Chem. Rev. 1979,28 117. ad E. L. Muetterties and J. Stein Chem. Rev. 1979,79,479. ' J. A. Timney Znorg. Chem. 1979,18,2502. T. Ziegler and A. Rauk Inorg. Chem. 1979,18 1755. H.-W. Chen and W. L. Jolly Znorg. Chem. 1979 18 2548. H.-W. Chen W. L. Jolly J. Kopf and T. HoLee J.Amer. Chem. SOC. 1979,101 2607. T. M. McHugh R. Narayanaswamy A. J. Rest and K.Salisbury J.C.S. Chem. Comm. 1979,208. Organ ometa llic Chemistry 191 have been used to assign the symmetry of the lowest ligand-field excited states of [Cr(CO),L] derivatives (L is a nitrogen donor).6 This evidence indicates that the substituent splits the eg 3d level so that the 3d,2(al) level is the lower energy partner. There have been a number of reports of 170 n.m.r. studies on metal carbonyl~.~ Terminal carbonyls resonate 300-400 p.p.m. downfield of 170H2 and the bridging groups in [(C5H5)2Ni2(g2-C0)2] gave a signal at 6512. Linewidths were about 10-30Hz but this may be smaller than "C for Mn and Co complexes. The relationships between 13C and 170 chemical shifts are somewhat confusing and demonstrate the complexity of the factors contributing to these parameters."0 Isotope shifts of 0.04 p.p.m. (upfield) have been observed in the 13C n.m.r. spectra of [W(CO),L] [L=CO PPh3 or P(OMe)3].8 A solution of [W(C0)5P(OMe)3] specifically '"0enriched in the equatorial sites was thus shown to scramble its label between axial and equatorial positions intramolecularly when kept at 78 "C for two days. A new preparation of [(C5H5)Nb(C0)4]has been rep~rted.~ This high-pressure carbonylation [(C5H5)2NbC12] gave over 50% yield of the tetracarbonyl. Cleavage of dimeric carbonyls by Li[R3BH] quantitatively forms the carbonylate anions which can be conveniently made to react further to form hydrides alkyls aryls and mixed-me tal dimers." Interaction of [HMn(CO),] or [Mn(CO)spy]' with neat H0,SCF3 has yielded [Mn(C0)5](03SCF3)." This salt appears to be a weakly associated ion pair with C4" symmetry at manganese; the co-ordinatively unsaturated cation rapidly forms an adduct with CO and MeCN.The crystal structure of the first hafnium carbonyl [(C5H5)2Hf(C0)2] reveals a Hf-C(0) distance of 216 prn.I2 The complex undergoes a single photochemical substitution with PPh3 or PF3 and forms a hafnacyclopentadiene complex with diphen ylacetylene. The stereochemistry of substitution of [Cr(L,)(CO),] (Lz =phen or bipy) to give fa~-[Cr(L~)L'(C0)~1 (L' =phosphine or phosphite) had been studied by 13C labelling experiments monitored by 13C n.m.r. and i.r.13 This work demonstrated that the Cr-CO bond cis to the two liganded nitrogen atoms is specifically cleaved in a dissociative process and that the five-co-ordinate intermediate is fluxional.Cations of the type [(C5H5)M(C0)2L]' (M = Ru L = CO MeCN MeNC or PR,; M=Os L=CO) react with liquid ammonia to form the neutral carbamoyl complexes [(CsH5)M(CO)L(CONH2)].'4The carbamoyl ligand in the complex G. Boxhoorn D. J. Stufkens P. J. F. M. v.d. Coolwijk and A. M. F. Hezemans J.C.S. Chem. Comm. 1979,1075. 'D. Cozak 1. S. Butler J. P. Hickey and L. J. Todd J. Mugn. Resonance 1979,33 149;Y.Kawada T. Sugawara and H. Iwamura J.C.S. Chem. Comm. 1979,291;S. Aime L.Milone D. Osella G. E. Hawkes and E. W. Randall J. Orgunometuffic Chem. 1979,178,171;J. P.Hickey J. R. Wilkinson and L.J. Todd ibid. 1979 179 159. D. J. Darensbourg J. Orgunometuffic Chem. 1979 174 C70; D.J. Darensbourg and B. J. Baldwin J. Amer. Chem. SOC.,1979,101,6447. W. A. Hermann and H. Biersack Chem. Ber. 1979,112,3942. lo J. A. Gladysz G. M. Williams W. Tam D. L. Johnson and D. W. Parker Inorg. Chem. 1979,18,553 1163. W. C. Trogler J. Amer. Chem. SOC., 1979,101,6459. D. J. Sikora M. D. Rausch R. D. Rogers and J. L. Atwood J. Amer. Chem. SOC.,1979,101 5079. I3 G. R. Dobson and K. J. Asali J. Amer. Chem. Soc. 1979,101 5433. l4 H. Behrens and A. Jungbauer Z. Nuturforsch. 1979,34b 1477. 192 A. J. Deeming and J. Evans [(C5H5)Ru(CO)2(CONH2)] is planar." Interaction between the Lewis acids EPh (E= Al Ga or In) and carbonylate anions occurs in two ways.16 Generally a bond is formed to the transition metal.In [(C5Hs)Fe(CO)2A1Ph3] the Fe-A1 bond length is 251 pm but in (Bun4N)[(C,H5)W(C0),.AlPh3] there is a W-C-0-A1 link. Both forms exist in a solution of (Bun4N)[(C5Hs)W(CO),GaPh3] in CH2C12. The anions [W(CO)5X]- (X = C1 Br I or NCO) which have ligand-field lowest excited states are photo-unreactive as is [W(CO),(CS)] which has a charge-transfer first excited state not involving a M-L g*-orbital." They display a third class of photoreactivity for [W(CO),L] derivatives. If L is an amine then amine dissociation occurs whereas M-L and M-CO dissociation pathways compete in phosphine complexes. The homogeneous carbonylation of methanol by iridium complexes has been studied." Two catalytic cycles were identified one involving [Ir(CO),I] and the other anionic complexes such as [MeIr(CO)213]-.The water gas reaction competes when [HIr(C0)213]- predominates and both HI and I-concentrations are important in determining which scheme is followed. Several ruthenium complexes have been found to catalyse the conversion of H2 and CO into methanol and methyl formate." Under the reaction conditions of 1300atm pressure (40 H2 60 CO) and 250-290 "C [RU(CO)~] is the only identifiable species. The reaction rate is proportional to the ruthenium concen- tration. Co-ordinated CO has been reduced to small hydrocarbons by alane.*' Whereas [RU,(CO)~~] yielded a mixture of products the Group VI hexacarbonyls formed ethylene with 95% selectivity. Treatment of a benzene solution of [W(CO),] and AlCl with CO and H2 at 200°C has afforded a mixture of alkylbenzenes Ph(CH,),H (n = 1-S) but no xylenes21 Temperature programmed desorption studies on [MO(CO)6] on silica gel show one narrow peak above 1000C.22 Some subcarbonyl species are formed but by 200 "C CO loss is complete.H2,C02,and CH are also eliminated. Subcarbonyls are also observed when [Fe(CO)J [Fe2(C0)J and [Fe3(C0)12] are supported on y-A1203 but above 300 "C oxidation by surface hydroxy-groups occurs.23 The stages from initial adsorption of these three compounds on the zeolite HY through to formation of Fe2' at 250 "C have been m~nitored.~~ Interestingly there is evidence for a Lewis acid p2-C0 interaction in [Fe3(CO),,]. Eight molecules of [MO(C0)6] are adsorbed into one unit cell of HY.25 E.s.r.measurements indicated that heating this material to 473 K in vacuo forms an Mo' species whereas more vigorous conditions yielded three types of Mo" sites. Dinuclear Carbony1s.-The co-condensation reactions between Ir atoms and CO at liquid helium temperatures have been reinvestigated following the discovery of a l5 H. Wagner A. Jungbauer G. Thiele and H. Behrens 2. Naturforsch. 1979,34b 1487. I6 J. M. Burlitch M. E. Leonowicz R. B. Petersen and R. E. Hughes Inorg. Chem. 18,1097. R. M. Dahigren and J. I. Zink J. Amer. Chem. SOC.,1979,101 1448. D. Forster J.C.S. Dalton 1979 1639. l9 J. S. Bradley J. Amer. Chem. SOC.,1979 101 7419. 'O C. Masters C. van der Woude and J. A. van Doorn J. Amer. Chem.SOC. 1979 101 1633. 'I G. Henrici-Olive and S. OlivC Angew. Chem. Internat. Edn. 1979 18 77. '* A. Brenner D. A. Hucol and S. J. Hardwick Znorg. Chern.,1979,18,1478. 23 A. Brenner and D. A. Hucol Inorg. Chem. 1979,18,2836. 24 D. Ballivet-Tkatchenko and G. Coudurier Inorg. Chem. 1979,18,558. '' P. Rommelfaenger and R. F. Howe J.C.S. Chern. Comm. 1979 123. Organometallic Chemistry supplier’s error.26 [Ir(CO),] formed at 10-12 K dimerizes on warming to 30-40 K. 1.r. evidence indicates that [Ir2(C0)8] is unbridged and above 200 K it yields larger unidentified clusters. Ab initio molecular orbital calculations on [(C5H5)2Fe2(CO)4] and [Fe3(C0)12]27 and extended Huckel calculations on [Fe2(C0)9]28 both indicate an absence of direct metal-metal bonding between the bridged iron-iron bond.The fragment orbitals of the terminal groups are directed towards the bridging ligands. In [Fe2(CO)9] for example the a-bonding orbital (al’)is of predominantly CO 0-character as is the 7-Fe-Fe bonding combination (e’). An e” set which are Fe-Fe antibonding but Fe-p-CO v*-bonding in character form the HOMO’S. The X-ray structure of [Pt2C12(p-CO)(p-dppm),] shows this complex to be of similar structure to its Pd analogue with a Pt-Pt separation of 316.2 The vco frequency of these two species differs by -80 cm-’ even though the structures are similar. The hydride in [NEt4][(p- H)MO,(CO)~PP~~] forms a highly unsymmetrical bridge being 168 pm from the MO(CO)~ group and 219 pm from the PPh3-substi- tuted m~lybdenum.~’ Crystal structure determinations on a number of mixed-metal dimers containing a (C,H5)2Nb unit have been reported.In [(C5H5)2Nb(CO)- (p-H)Fe(C0)4]31 and [(C5H5)2Nb(CO)(p-CO)Co(C0)4]32 the bridging ligands are a hydride and semi-bridging carbonyl respectively. The Nb-Mo bond in [(C5H5)3NbMo(C0)3](l),formed by the reaction between [(C5H5),Nb]BH4 and [(C5H5)Mo(CO)3Me],is bridged by both an unsymmetrical bridge (vco 1700 cm-’) and a v-bonded carbonyl group (vco 1560 ~m-l).~~ 0 0‘ (1) The bridged metal-metal bond in [(~-AsM~~)F~(CO)~M(CO)~] (M = Co n = 3; M=Mn n =4) can be cleaved by a ligand L [L =PMe3 or P(OMe)3] as shown in Scheme l.34 Subsequent CO loss reforms the metal-metal bond and the stepwise substitution process can be repeated to give tetrasubstituted p-AsMe2 complexes 26 A.J. L Hanlan and G.A. Ozin J. Organometallic Chem. 1979,179,57;J. Amer. Chem. SOC.,1979,101 5456. ” M. Benard Znorg. Chem. 1979 18 2782. 28 R. H. Summerville and R. Hoffmann J. Amer. Chem. SOC.,1979,101 3821. 29 M. P. Brown A. N. Keith Lj. ManojloviC-Muir K. W. Muir R. J. Puddephatt and K. R. Seddon Inorg. Chim. Acta 1979 34 L223. 30 M. Y. Darensbourg J. L. Atwood R. B. Burch jun. W. E. Hunter and W. Walker J. Amer. Chem. SOC. 1979,101,2631. 31 K. S. Wong W. R. Scheidt and J. A. Labinger Znorg. Chem. 1979 18 136. 32 K. S. Wong. W. R. Scheidt and J. A. Labinger Znorg. Chem. 1979,18 1709. 33 A. A. Pasynskii Yu. V. Skripkin J. L. Eremenko V. T. Kalinnikov C. G. Aleksandrov V. G. Andrianov and Yu.T. Struchkov J. Organometallic Chem. 1979,165,49. 34 H.-J. Langenbach and H. Vahrenkamp Chem. Ber. 1979,112,3373,3390. A.J. Deeming and J. Evans Me2 Me2 Me2 L -co 7\ + (OC),Fe/"i+ 7\ (OC),Fe -M ' (C0)n M'(CO),L (OC),Fe -M (CO) -,L Scheme 1 [AsMe2CoFe(CO)4L4] and Fe -Mn- bonded [AsMe2FeMn( CO) 5L3] species. Photo- substitution of P(OPf) into [(C5H5)2Fe2(C0)4] has yielded a yellow intermediate stable at -78 0C.35 This species does not exhibit a u +u*transition near 350 nm but does have a vco bond at 1720 cm-' in its i.r. spectrum. A CO-bridged adduct with no Fe-Fe bond [(C5H5)(CO){P(OPri)3)Fe(p-CO)Fe(C5H5)(C0)2], was suggested. Quantum yields for photoreaction of [(C5H5),M2(CO),] (M = Fe or Ru) and CCl to give [(C5H5)M(CO)2C1] have been measured in different For the ruthenium complex they are invariant even though the proportions of bridged and non-bridged isomers differed considerably.Evidently the carbonyl bridges are cleaved by the excitation. Attempted thermal phosphite substitution of the ruthenium dimer at 140"C interestingly resulted in alkyl abstraction from the phosphite to form [(C5H5)Ru(C0)2R].37 In contrast PPr3 evidently forms [(C~H,)~RU~(CO)~(PP~,)I and [(C,H,)Ru(Co)2(PPr,)H]. Thermolysis of [(C,Me,)Rh(CO),] has afforded [(p-C0)2Rh2(C5Me,)2] as an air-sensitive blue solid.38 Treatment of a THF solution of [(C,Me,)Co(CO),] with sodium yields the monoanion [(p-CO),Co,(C,Me,)]- which is oxidized to the neutral analogue of the rhodium dirner.,' This oxidation causes a slight shortening of the Co-Co distance from 237.2 to 233.8 pm which does not reflect the magnitude of the formal Co-Co bond-order change from 1.5 to 2.In contrast reduction of [(p-PPh2)2Fe2(C0)6] to its dianion increases the Fe-Fe separation from 268.3 to 363.0 pm and there is a concomitant flattening of the Fe2P2 ring.40 A mixture of [Co,(CO),] and dppe has been found to mediate the hydro- formylation reaction with water as the hydrogen source.41 This occurs when the solvent is an ether but in NEt solution the water gas shift is predominant. Irradiation of a solution of [CO,(C~)~(PBU"~)~] at 355 nm causes little photocata- lytic activity towards pent-l-ene., This is thought to be due to the rapid recom- bination of any cobalt monomers so generated.However addition of HSiEt markedly increases photocatalytic activity causing olefin isomerization and some hydrogenation. The key steps are thought to involve [HCO(CO)~(PR,)] and [H,Co(CO),(SiEt3)(PR,)l. Polynuclear Carbony1s.-The He-I and -11 U.V. p.e. spectra of [RU,(CO)~~] and [OS,(CO)~~] each show a first ionization potential at -7.8 eV assigned as due to an 35 D. R. Tyler M. A. Schmidt and H. B. Gray J. Amer. Chem. SOC. 1979,101,2753. 36 H. B.Abrahamson M. C.Palazzotto C. L.Reichel and M. S.Wrighton J. Amer. Chem. SOC.,1979,101 4123. 37 J. A. S. Howell and A. J. Rowan J.C.S. Chem. Comm. 1979,482. 38 A.Nutton and P. M. Maitlis J. Organometallic Chem. 1979,166 C21. 39 R. E.Ginsburg L. M. Cirjack and L. F. Dahl J.C.S. Chem.Comm. 1979,468. 40 R. E.Ginsburg R. K. Rothrock R. G.Finke J. P. Collman and L. F. Dahl J. Amer. Chem. SOC. 1979 101,6550. 41 K. Murata A. Matsuda K.4. Bando and Y. Sugi J.C.S. Chem. Comm. 1979,785. 42 C. K.Reichel and M. S. Wrighton J. Amer. Chem. SOC.,1979,101,6769. Organome tallic Chemistry 195 a; M-M bonding orbital.43 This can be compared with a value of -4.8 eV for the metal’s work function. Increasing the cluster nuclearity to six in [os6(co)1,] only reduces the first IP to 7.5 eV. The electronic spectrum of [RU~(CO)~~] contains a band at 390 nm which is polarized in the Ru3 plane and has been assigned as (+ +(+* transition while a weak band at 320nm was considered to be within the (+* manifold.44 The iron and osmium analogues exhibit similarly polarized absorptions at 602 and 437 nm and 385 and 330 nm respectively.The X-ray photoemission spectra of the [Pt3(C0)6];- series of anions are very similar in the valence region suggesting that there is little interaction between the Pt 5d-derived orbitals between Pt3(C0)6 The relationship between the M-H stretching vibrations of p2-H ligands and the MHM angle has been in~estigated.~~ A heavy-atom model would predict that ;as,,,,,/~sym = tan (8/2) but there is increasing deviation from this at high bond angles. A better fit was found between vaYmand sin (8/2). pK values and deprotonation rate constants have been measured for a number of hydridocarbonyl complexes in methanol The reprotonation rates of the [H3M4(C0)12]- (M =Ru or 0s) ions are unusually low and this may be due to required hydride positional changes.There have been several interesting reports concerning clusters with encapsulated atoms. Protonation of [co6(co)15]’- has yielded PPN[HCO~(CO)~~] which exhibits a proton resonance at ~523.2.~’ The hydride was located at the centre of the octahedron by neutron diffraction (Co-H 182 pm). Its inclusion causes the average Co-Co distance to increase from 250.8pm in the dianion to 257.9pm. An interstitial metal hydride vibration has been established in [Me4NJ[HRh(CO)18J using 2Hlabelling.49 The tl mode was observed at -825 cm-’ and 600 cm-’ for the ‘H and 2H species respectively; the Ru-H force constant was estimated at 21 N nm-’ only 20% of p2-H values.46 13C Labelling experiments have also been used to identify vibrations due to the interstitial carbide in [(~3~s)2c06c(co)~2]~50 Bands at 819 and 790 cm-’ were assigned to az”and e’ motions of the carbon atom within the D3hcage respectively.Carbide vibrations were tentatively assigned for [Fe5C(CO)1S;1 (790 and 770 cm-’) and K,[Rh,C(CO),,] (694 cm-’). A reaction of a carbidic centre has been observed.” Treatment of (NEt4)2[Fe6C(C0)16] with C7H7Br in methanol afforded (NE t4)[Fe4C(CO) 2C02Me J (2). The me thoxycar- bony1 group can be hydrogenated from the cluster to form methyl acetate. Syntheses of the [M6N(C0)15]- (M = Co or Rh) anions have been Both can be prepared by treatment of [M6(C0),,]’- with [NOJBF, although the rhodium complex is obtained in higher yield from K3[Rh7(C0)16] under a CO and NO 43 J.C. Green E. A. Seddon and D. M. P. Mingos J.C.S. Chem. Comm. 1979,94. 44 D. R. Taylor R. A. Levenson and H. B. Gray J. Amer. Chem. SOC.,1978,100,7888. 45 G. Apai S.-T. Lee M. G. Mason L. J. Gerenser and S. A. Gardner J. Amer. Chem. SOC.,1979 101 6880. 46 M. W. Howard,V. A. Jayasooriya S. F. A. Kettle D. B. Powell and N. Sheppard J.C.S. Chem. Comm. 1979 18. 47 H. W. Walker C. T. Kresge P. C. Ford and R. G. Pearson J. Amer. Chem. SOC.,1979,101,7428. 48 D. W. Hart R. G. Teller C. Y. Wei R. Bau G. Longoni S. Campanella P. Chini and T. F. Koetzle Angew. Chem. Internat. Edn. 1979,18 80. 49 I. A. Oxton S. F. A. Kettle P. F. Jackson B. F. G. Johnson and J. Lewis J.C.S. Chem. Comm. 1979 687. 50 G. Bor and P. L. Stanghellini J.C.S.Chem. Comm. 1979 886. 51 J. S. Bradley G. B. Ansell and E. W. Hill J. Amer. Chem. SOC.,1979 101 7417. 52 S. Martinengo G. Ciani A. Sironi B. T. Heaton and J. Mason J. Amer. Chem. SOC.,1979,101,7095. A.J. Deeming and J. Evans (2) mixture. The 15N resonance from an enriched sample of the rhodium anion was observed as the central five lines of a binomial septet indicating equal coupling to the six rhodium nuclei which are at the vertices of a trigonal prism. However the phosphorus atom in [co6(co)16P]- synthesized from PCl3 and [co(Co),]- appears to be too large to fit inside a p~lyhedron.~~ Structure (3) was characterized by an 00 1-(3) X-ray diffraction study on the [PPhJ' salt. [BZNE~~]~[R~~(CO)~~P] has been isolated from a reaction mixture of [Rh(a~ac)(CO)~] PPh3 caesium benzoate and 400atm of CO/H at 140-160 "C in tetraglyme The phosphorus atom was shown to be within a capped square antiprism of rhodium atoms.However at 35°C the 31Pn.m.r. signal is a decet suggesting that this skeleton is fluxional. 13C{103Rh} N.m.r. studies on [Rh,(C0),6]3- have assisted in assigning the 13C n.m.r. spectrum and given lo3Rh chemical shifts.55 The room-temperature exchange between three edge-bridging and three terminal carbonyls was shown to be real and not an apparent consequence of a fluxional metal cage within a fixed CO frame. There are two encapsulated platinum atoms in the anion [Ptl,(C0)22]4- (4) synthesized by thermolysis of [Pt9(C0)18]2-.56 The idealized point group for the Pt cage is D5,,,reminiscent of some of the five-fold symmetry growth patterns suggested for small atomic clusters.This cluster also has a very low CO/M ratio [there are three CO environments in (4),two terminal a and b and one bridging c] and so may be approaching the type of metal particles present in supported heterogeneous catalysts. A number of smaller clusters reported this year show some notably unusual features. [(C,H,),V,(CO>,] a thermolysis product of [(C5H5)2V2(CO)5] has been 53 P. Chini G.Ciani S. Martinengo A. Sironi L. Longhetti and B. T. Heaton J.C.S.Chem. Comm. 1979 188. 54 J. L. Vidal W. E. Walker R. L. Pruett and R. C. Schoening Znorg. Chem. 1979,18 129. " C. Brown B. T. Heaton L. Longhetti D. D. Smith P. Chini and S.Martinengo J. Organometallic Chem. 1979,169,309. 56 D. M. Washecheck E. J. Wucherer L. F. Dahl A. Ceriotti G. Longoni M. Manassero M. Sansoni and P. Chini J. Amer. Chem. Sac. 1979,101 6110. Organometallic Chemistry co b co C (4) characterized spectroscopically.s7 It apparently has only terminal carbonyl groups and so presents a theoretical challenge. On one hand the 18-electron rule would require 12 two-electron metal-metal bonds and on the other skeletal electron counting rules indicate that there are zero skeletal electron pairs. Photolysis of [(C5H5)Nb(C0)J has yielded [(CsH5)3Nb3(C0)7] (9,in which one carbonyl group (5) appears to act as a six-electron dor,or by v2co-ordination to two Nb This CO bond is comparatively long (130pm) and accordingly has a low vc0 at 1330cm-'.Complex (6) contains an FesAg triangle with Fe-Fe and Fe-Ag bond lengths of 262.8 and 270pm respecti~ely.~~ The silver atom was found to be weakly co- ordinated to one double bond in a solvating toluene molecule. The crystal structure HMeN Ph \/ C I CH 57 W. A. Herrmann J. Plank and B. Reiter J. Organometallic Chem. 1979,164 C25. 58 W.A. Hermann M. L. Ziegler K. Weidenhammer and H. Biersack Angew. Chem. Internat. Edn. 1979 18 960. 59 A. J. Carty G. N. Mott and N. J. Taylor J. Amer. Chem. Soc. 1979 101 3131. A. J. Deeming and J. Evans of [(C,H,)MO(CO)~H~MO]~ (7) indicates two types of Mo centres6' The extra; cubane molybdenum centre is commonplace but the four molybdenum atoms in the Mo Mo C tbane are considered to be ligand free.There are marked distortions in the cube a i evidenced by three types of Mo-Hg distance (319,310 and 256 pm). Last year's report of a tetrahedral cluster with four different vertices [Fe Co Mo and S) has been extended to produce a compound with four different metal atoms at the vertices.6' Refluxing [FeCoMoS(C,H,) (CO),] with [AsMe2W(CO)3(C,H5)] in ben- zene for one day afforded [F~COMOWS(ASM~~>(C,H~)(CO)~] in 42% yield. [H20~3(C0)10]and [H20~3(C0)10(CH2)] have been studied by neutron diffraction.62 In the latter complex the hydride-bridged 0s-0s edge (305.3pm) is longer than the unbridged one (285.5pm); the edge with both CH2 and H bridges is the shortest (282.4 pm).[HRu3(CO)J has been prepared by treating [Ru3(C0),,] with NaB&,63 methanolic KOH,64 and aqueous NEt3;65 the last method is also applicable to the iron and osmium complexes. Alkylation of the p-CO group has been achieved using electrophilic reagents to form [HM3(CO)lo(p-COMe)].6s*66 The iron complex has also been prepared by protonation of [Fe3(CO)l,(p-COMe)]-.67 These complexes react with hydrogen (1atm) to form [H2M3(C0)9(p3- COMe)] and hydrogenolysis of the ruthenium complex occurs with 500 psi of CO/H2 at 130"C to form dimethyl ether and [RU~(CO)~~].~' with KOH can also give a high Treatment of [RU~(CO)~~] yield of [RU6(C0)18I2- under different condition^.^^ The anion was shown to possess idealized C2symmetry with two (p3-CO)and two (p2-CO) groups.This completes the series [M6(co)18]2- [Hh&(CO)18]- and [H2M6(C0)18] (M = Ru or 0s) and no pair of analogues has the same structure. 6o J. Deutscher S. Fadel and M. L. Ziegler Chem. Ber. 1979,112 2413. 61 F.Richter and H. Vahrenkamp Angew. Chem. Internat. Edn. 1979,18 531. 62 R. W. Broach and J. M. Williams Inorg. Chem. 1979,18 314;A.J. Schultz J. M. Williams R. B. Calvert J. R. Shapley and G. D. Stucky ibid. p. 319. 63 B. F. G. Johnson J. Lewis P. R. Raithby and G. Suss J.C.S. Dalton 1979 1356. P. F. Jackson B. F. G. Johnson J. Lewis M. McPartlin and W. J. A. Nelson J.C.S. Chem. Comm. 1979 735. 6s J. B. Keister J.C.S. Chem. Comm. 1979 214. 66 B. F. G. Johnson J. Lewis A. G. Orpen P. R. Raithby and G. Suss,J. Organometallic Chem. 1979,173 187.67 H.A.Holadi and D. F. Schriver Inorg. Chem. 1979,18,1236. Organometallic Chemistry 199 [Co3(C0),PR) and [CoFe2(CO),PR] derivatives have been The metal-metal bonds of the former complex are -10 pm longer indicating that its extra electron is in a M-M antibonding orbital. Its 22-line e.s.r. spectrum shows hyperfine coupling to three 59C0 nuclei but not to ,lP so this electron is located largely on the cobalt atoms. The e.s.r. spectrum of [Co2Fe2(C0),PR]- also exhibits hyperfine coupling to ,,Co only so the lowest unoccupied molecular orbital of the neutral mixed-metal cluster is also primarily metal in character. The crystal structure of [Co3(C0),(~,-GeCo(C0),)3 shows that the Co-Co bond length is 261 pm significantly longer than the tricobalt carbon derivatives (-250 ~m).~ Spectro-scopic evidence has been obtained for [Co,(CO),(~,-SnMe)1,’” but the attempted incorporation of bismuth into a CO~E Formation of core yielded B~[CO(CO)~],.~~ [CO~(CO)~~]-has been shown to be strongly dependent on cation and solvent and was optimized for Li’ in Bu”,O.’~ Two equilibria (2) and (3) are set up.Addition of THF drives (2) to the left and retaining CO to offset this yields [CO~(CO)~~. M[Co(C0)4] +[CO,(CO)~] S M[CO,(CO)IOI+2CO (2) $ ~M[CO~(CO)IOI (3) 2M[Co(C0)4]+[CO~(CO)I~] Protonation of L~[CO~(CO)~~]E~~O by dry HCl at -20°C yields the air- and moisture-sensitive [Co,(CO),C(OH>].” Heating to 40“C causes oxygen to metal hydrogen transfer forming [HCO(CO)~] A transient species was and [CO~(CO)~,].observed by i.r. spectroscopy and this was isolated at 15 OC.14 This was formulated as [HCo,(CO),] and shown crystallographically to have structure (8).The hydrogen is thought to adopt two sites in the crystal on either side of the CO plane. This hydride reacts with acetylene at room temperature to form [Co,(CO),CMe]. (Ca2 (CO) (8) (9) Treatment of a solution of [(C5Me5)Co(C0),] with sodium sand generates a mixture of N~[CO,(C,M~,),(,Z-CO)~] and subsequent protonation and N~[CO(CO)~] H. Beurich T. Madach F. Richter and H. Vahrenkamp Angew. Chem. Internat. Edn. 1979,18,690. 69 R. Boese and G. Schmid J.C.S. Chem. Comm. 1979 349. 70 K.E.Schwarzhans Z. Narurforsch. 1979,34b 1456. ” G.Etzrodt R. Boese and G.Schmid Chem.Ber. 1979,112,2574. 72 G. Fachinetti J.C.S. Chem. Comm. 1979 396. 73 G.Fachinetti J.C.S. Chem. Comm. 1979 397. 74 G.Fachinetti S. Pucci P. F. Zanazzi and U. Methong Angew. Chem. Internat. Edn. 1979,18,619. 200 A. J. Deeming and J. Evans yields [CO~(C~M~,)~(CO),(~- CO)(p3-CO)Z]as a green air-sensitive solid.75 The structure suggests an insertion of CO~(CO)~(~-CO) across a Co-Co double bond in [(CSMeS)zCoZ(p-CO>Z]. Polynuclear cobalt clusters have been synthesized by reac- tion of [(q3-C3H5)Co(C0)3] with L3M-PMe2H specie^.'^ Propene is eliminated and a bridging PMeZ group is generated. In the case of the [CO(CO)~(NO)PM~~H] reaction one product is [CO~(PM~~)~(CO) ,] which possesses an edge-bridged tetrahedral c0 core. [Rh5(CO)141]2-(9) has been obtained by reaction of [Rh4(C0)1Z]with AsPh41 or NBu41 in propan-2-01.~~ It is stable only under CO and reacts with 0.5 [Rh4(CO)1Z]or [Rh(C0)2(MeCN)Z]' to form [Rh7(C0)16II2- and [Rh6(CO)151]- respectively.Like [Ni5(C0),,l2- it has 76 valence electrons at the metal as opposed to 72 for [OS,(CO)~~]*- all these anions having trigonal- bipyramidal metal polyhedra. [RU~(CO),~] acts as a precursor for a homogeneous water gas shift catalyst.78 Under the reaction conditions [H3Ru4(C0)J and [HRU~(CO)~,]- are the principal species. Solutions of both iron and ruthenium carbonyls forming mixed-metal clusters are more active than homometallic systems. [RU~(CO),~] catalysis of the Fischer-Tropsch reaction at -250 "C has been monitored by i.r.Carbonyl vibrations are lost after -25 h and only then does the catalysis occur evidently by a heterogeneous process. Photolysis of [Ru,(CO),(PPh3),] is thought to generate a cluster which acts as a pent-1-ene isomerization catalyst.*' Irradiation of [H3Re3(CO),,] with 313 or 366 nm light causes quantitative formation of [H2Re2(C0)8].81 Under CO [HRe(CO),] and [H2Re2(C0)8] are considered to be formed initially although [HRe(CO)J and [ReZ(CO)lo] are the eventual products. The primary photoreaction may be either Re-Re bond cleavage or CO loss going on to form [HRe(C0)4] and [HZRe2(C0)7or 81. Adsorption processes for [Rh6(CO)16] have been shown to be support-depen- dent.82 If the water content on alumina is low then a hexanuclear unit is thought to be maintained; otherwise Rh' carbonyls are formed.Bimetallic clusters have been anchored to PPhZ-functionalized poly(styrene-divinylbenzene) and silica gel.83 Both [FeZPt(CO),{PPh2-@}J and [RuPtZ(CO),(PPhZ -were found to be ethylene hydrogenation catalysts and the form of the rate law indicated that both H2 and ethylene were bonded to the catalyst. [H2Os3(CO),(PPh2>-SIL] and [HOS~AU(CO)~~(PP~~)-SIL] displayed no activity towards propene hydrogenation at 100"C but did catalyse butene isomerization at 110 "C; the former was ten times more active. 75 L. M. Cirjak R. E. Ginsburg and L. F. Dahl J.C.S. Chem. Comm. 1979,470. 76 E. Keller and H. Vahrenkamp Chem. Ber. 1979,112,2347. 77 S. Martinengo G. Ciani and A. Sironi J.C.S. Chem. Comm.1979 1059. 78 C. Ungermann V. Landis G. A. Moya H. Cohen H. Walker R. G. Pearson R. G. Rinker andP. C. Ford J. Amer. Chem. SOC. 1979,101 5922. 79 M. J. Doyle A. P. Kouwenhaven C. A. Schaap and B. van Oort J. Organometallic Chem. 1979,174 c55. J. L. Graff R. D. Sanner and M. S. Wrighton J. Amer. Chem. SOC. 1979,101 273. R. A. Epstein T. R. Gaffney G. F. Geoffroy W. L. Gladfelter and R. S. Henderson J. Amer. Chem. SOC.,1979 101 3847. A. K. Smith F. Hughes A. Theolier J. M. Basset R. Ugo G. M. Zanderighi J. L. Bilhou V. Bilhou-Bougnol and W. F. Graydon Inorg. Chem. 1979,18 3104. 83 R. Pierantozzi K. J. McQuade B. C. Gates M. Wolf H. Knozinger and W. Ruhmann J. Amer. Chem. SOC.,1979 101 5436. Organometallic Chemistry 201 2 Carbonyl Analogues and COzComplexes Charge-transfer excitation (282 nm) of [Ru(CN),I4- [Mo(CN),I4- and [W(CN)J4- in degassed CHCl causes a one-electron oxidation of each anion.84 Since the solvent is the oxidant the charge-transfer band is thought to have some metal-to-solvent character.Photoinduced (A > 460 nm) reduction of K,Fe(CN) by FeCl has been achieved in a liposome system (from egg yolk lecithin)., The iron complexes do not cross the phospholipid wall avoiding formation of Turnbull’s Blue and Leuco Methylene Blue acts as the photosensitizer. Irradiation of a solution of [Mo(CN)J3-in MeOH-CHCl with 365 nm light generates [(CN),MO(CN)MO(CN)~]~- and [Mo(CN),I2- within 5 s.’~ With the aid of radical trapping agents three primary photoreactions were proposed [equations (4)-(6)].U.V. [Mo(CN),I3- -+ [Mo(CN),]~-+ H’ + -0Me MeOH (4) U.V. -+ [Mo(CN)7I3-+ CN. (5) U.V. -+ [MO(CN),]~-+ CN- (6) Pulse y-radiolysis of salts and aqueous glasses of [Ni(CN)4]2- at 77 K generates [Ni(CN)4]3- [Ni(CN)4]- and [HNi(CN)4]2-.87 The barium salt in particular gave a good yield of the hydride complex. Its e.s.r. spectrum contains a large ‘H hyperfine coupling indicating that the odd electron is ca. 30% on hydrogen probably in a Ni-H cr*-orbital. The structure of Rb2[Pt(CN)4]C10.3.3H20 has been determined at 110 and 298 K by neutron diffraction.*’ At the lower temperature the average Pt-Pt separation is -2 pm less but the marked alternation of Pt-Pt distances observed at 298 K is reduced. The decreased average distance may be expected to give rise to a conductivity increase at low temperatures but the opposite is true.Circular dichroism patterns have been obtained for monomeric Cs2Pt(CN) and a helical stacked form in a chiral phase viz. hydroxypropylcellulose.89 These have been used to assign the symmetries of the electronic excited states of these species. [(C,H,)Cr(NO)(CO)(CS)] has been synthesized by reaction of the cyclo-octene complex [(C,H,)Cr(No)(Co)(C,H14)]with CS2 and PPh,.” Substitution of the carbonyl groups is preferred allowing isolation of [(C5H,)Cr(CS)(NO),]PF6. CSSe has been found to be a useful thiocarbonyl prec~rsor.~~ The complexes [(C5H,)M(PMe3)(q2-CSSe)](M = Co or Rh) each form [(C5H5)M(PMe3)(CS)] on treatment with PPh3. The first p3-CS complex [((C,H,)CO}~(~~-CS)(~~-S)] has been isolated from the reaction between [(C,H,>Co(PMe,)(CS,)] and [( C5H5)( PMe,)Co( p-CO),Mn( CO)( C,H4Me)].92 The thiocarbonylwlphur exhibits 84 A.Vogler W. Losse and H. Kunkely J.C.S. Chem. Comm. 1979 187. 85 Y. Sudo and F. Toda J.C.S. Chem. Comm. 1979 1044. 86 D. Rehorek J. Salvetter A. Hantschmann H. Hennig Z. Stasicka and A. Chodkowska Inorg. Chim. Acta 1979 73,L471. M. C. R. Symons,M. M. Aly and D. X. West J.C.S. Chem. Comm. 1979,51;J.C.S. Dalton 1979,1744. s8 R. K. Brown and J. M. Williams Inorg. Chem. 1979,lS 1922. 89 F. D. Saeva G. R. Oh R. F. Ziol and P. Day J. Amer. Chem. Soc. 1979,101 5419. 90 M. Herberhold and P. D. Smith Angew. Chem. Internat. Edn. 1979,18,631. 91 H. Werner and 0.Kolb Angew.Chem. Internat. Edn. 1979,18 865. 92 H. Werner and K. Leonhard Angew. Chem. Internat. Edn. 1979,18,627. 202 A. J. Deeming and J. Evans to Lewis base character. LiPh reacts with [(CsHs)W(PPh3)(CO)(CS)I]form [(CsHs)W(PPh3)(CO)(CSPh)].93 This complex has a long C-S bond (171.6 pm) and a short W-C distance (180.7 pm) and appears to be best formulated as a carbyne complex. Quadruple Mo-Mo bonds in e.g. [Mo,(OAc),] are readily cleaved by iso- cyanides initially forming e.g. [(RNC),MO(OAC)~].~~ Subsequent treatment with non-co-ordinating anions and excess ligand yields [Mo(CNR),]X2; the X-ray struc- ture of [Mo(CNMe),](BF,) shows a distorted co-ordination geometry near to capped octahedral. Oxidative addition of I2 to [PhCH,NC),Rh]I occurs over three rhodium atoms forming [(PhCH2NC)12Rh312]13 which has a linear I-Rh-Rh-Rh-I This trinuclear cation undergoes dissociation in solution.Irradiation of a solution of [Rh2(L2)4]2c [L,= CN(CH2)3NC] in aqueous HCl generates hydrogen and [Rh2(L2)&l2I2+, the structure of which has been determined cry~tallographically.~~ Oxidation of the initial dication in aqueous H2SO4 yields [Rh2(L2),,+In aggregate^.^^ Flash photolysis of this species generates a transient which decays back to the oligomer with second-order kinetics suggesting that this is actually a dimer. In the presence of Fe3+ the blue cation [Rh2(L2),I4+ is obtained and this is considered to be the photoactive species in the reaction between [Rh2(L2),I2+ and HCI. MeNC inserts into a metal hydrogen bond in [(CsMes)2ZrH2] at -65 "C to form [(CsMes)2Zr(H)(CH=NMe)] which is hydrogenated to [(CSMeJ2Zr( H)(NMe2)] at room temperat~re.~' The steps in this hydrogenation were identified using a more bulky isocyanide.[(CsMes)2Zr(H)(CH=NC6H3Me2)] isomerizes to [(CSMe5)2Zr(q2-CH2NC6H3Me2)] at 25 "C. Exposure to hydrogen then pro- duces a metallated product but in the presence of Me1 the imine complex [(CsMe5)2Zr(I){N(Me)C6H3Me2}] can be isolated. Bu'NC forms an adduct with [H20~3(C0)10] and mild heating causes loss of one CO group to give [H20~3(C0)9(CNBu')].99 However under more vigorous condi- tions (refluxing Bu20) an insertion reaction occurs to form (10;M = 0s). In the presence of NEt, [H20~3(CO)10(CNBu')] forms (1 1) at room temperature; proton transfer from osmium to nitrogen is evidently mediated by the base.Refluxing [Ru~(CO)~~CNBU'] in cyclohexane solution under hydrogen for 90 min gives rise to (10; M = Ru) as the major product."' These complexes are similar to (12) and (13) formed by protonation of the anions formed in the reactions of [HFe3(CO)1J and organic nitriles in the presence of I-.1o1 (12) is obviously related to (10) and isomerizes to (13) at 65 "C. Reaction of [&(CNBUt)6] with SiPh2MeH yields a 93 W. A. Greaves R. J. Angelici B. J. Kelland R. Klima and R. D. Jacobson J. Amer. Chem. SOC.,1979 101,7618. 94 G. S. Girolami and R. A. Anderson J. Organometallic Chem. 1979,182 C43; P. Brant F. A. Cotton J. C. Sekutowski T. E. Wood and R. D. Walton J.Amer. Chem. SOC., 1979,101,6588. 95 A. L. Balch and M. M. Olmstead J. Amer. Chem. SOC.,1979,101,3128. 96 K. R. Mann R. A. Bell and H. B. Gray Inorg. Chem. 1979,18,2671. 97 V. M. Miskowski I. S. Sigal K. R. Mann H. B. Gray S. J. Milder G. S. Hammond and P. R. Ryason J. Amer. Chem. SOC., 1979 101,4383. 98 P. T. Wolczanski and J. E. Bercaw J. Amer. Chem. SOC.,1979,101,6450. 99 R. D. Adams and N. M. Golembeski J. Amer. Chem. SOC., 1979,101,2579,2225; Inorg. Chem. 1979 18 1909. loo M. I. Bruce and R. C. Wallis I. Organometallic Chem. 1979,164 C6. lo' M. A. Andrews and H. D. Kaesz J. Amer. Chem. SOC., 1979,101,7238; M. A. Andrews G. van Buskirk C. B. Knobler and H. D. Kaesz ibid. p. 7245. 203 Organometallic Chemistry HCMe MeC-NH dimeric product [(p-CH=NBu'),{Pt(SiPh,Me)(CNBu'))zl which possesses a six- membered Pt-N-C-Pt-N-C ring in a boat conformation.lo2 [(C5H5),Ti(C0),] reacts with CO to liberate CO and form carbonate ligands in (14) characterized crystallographically.'03 In contrast the zirconium analogue (CsHs)2 (14) gives rise to [(C5H5)2Zr0]3 which has an approximately planar Zr-0-Zr-0-Zr-6 ring.Labelling experiments have established equation (7) 4[(C5H5)2Ti(C0)2]+4l3CO2 + [{(C5H5)2Ti}2(13C03)]2 +2l3CO+8CO (7) Model experiments for this reaction were carried out using OC(C02Et) and N(p- tolyl)=C=N(p-tolyl) as These couple to form the metallo- and cycles [(C5H5)2Ti{OC(C02Et)2C(C02Et)20}][{(C5H5)2Ti}2{[(p-tolyl)N]2-CC[N(p- t01~1)12}1. 3 Alkyls Aryls and Acyls Metal alkyl complexes have been synthesized by co-condensing a metal vapour and CH3- CF3* and SiF3* radicals generated from their dimers by a radiofrequency discharge at -196 OC.lo5 This method was extended to the reaction between CF3* lo' M.Ciriano,M. Green. D. Gregson J. A. K. Howard J. L. Spencer F. G. A. Stone and P. Woodward J.C.S. Dalton 1979 1294. lo3 G. Fachinetti C. Floriani A. Chiesi-Villa and C. Guastini J. Amer. Chem. SOC.,1979,101 1767. '04 M. Pasquali C. Floriani A. Chiesi-Villa and C. Guastini J. Amer. Chem. SOC.,1979 101 4740. lo' T. J. Juhlke R. W. Braun T. R. Bierschenk and R. J. Lagow J. Amer. Chem. SOC.,1979,101,3229. A. J. Deeming and J. Evans radicals and XeF2 to synthesize the first organoxenon compound Xe(CF3)2.'06 Xe(CF3)2 decomposes to XeF2 and a mixture of fluorocarbons at 20°C and this process is markedly catalysed by metal halides such as AgCl KBr and CsI. Nevertheless i.r. and 19Fn.m.r. spectra were obtained. Lithium vapour reacts with HgEt2 quantitatively to form Hg and what is thought to be CgLi6,"' based on hydrolysis experiments. Similar treatment of PbEt and SnEt gave mainly EtLi and ca. 10% C2Li6. 13C N.m.r. of CH3CH2'3CH26Li has been particularly useful since quadruple relaxation of the 6Li nucleus (I= 1)is slow and J13c& can be observed.'o8 A nine-line pattern was observed for the carbon bound to lithium at -50 "C and the intensity distribution indicates coupling to six lithium nuclei. This suggests rapid intramolecular exchange of propyl groups in a hexameric unit; intermolecular exchange is apparent at higher temperatures.The Gaussian 70 suite of ab initio calculations has been used to investigate C5H4-nLin(n = 1-4).lo9 In general multi- centre lithium bonding is preferred to terminal environments. C9H9EX3 (EX3 =SnH3 SnMe3 or GeH3) species are fluxional between -90 and +5 "C; a 1,9 shift mechanism was proposed.110 Polar solvents such as DMF DMSO and HMPA affect the ring proton chemical shift of C9H9SnMe3 and it was shown that this complex is in equilibrium with an ion pair (C9H9)-[SnMe3(S)]' (S= solvent).'" This allows an intermolecular exchange process. Similarly addition of polar solvents to a solution of C5H5SnMe3 causes the tin satellites to broaden again indicating an intermolecular process via (C5H5)-[SnMe3(S)]'.Chiral silylcyclopentadienyl complexes of the type R(C1)(H)SiC5H5 have been All five ring carbons are now inequivalent and this gives extra mechanistic information about the shift mechanism. The 13C resonances due to the a-carbons broaden more quickly with increasing temperature than the @-resonances suggesting a 1,2 silyl shift process. Slow addition of Me2SiC12 to sodium/potassium alloy in THF and subsequent hydrolysis yields a mixture of cyclopolysilanes (Me2Si)n.113 In addition to the penta- and hexa-mers reported previously h.p.1.c. has been used to identify oligomers up to n = 35. Photolysis of (Me2Si) with 254 nm light yields (Me2Si) and Me2Si.l14 The silene normally polymerizes but can be trapped in hydrocarbon glasses at 77 K or Ar matrices at 10 K as a bright yellow material.No e.s.r. signal is observable indicating that it is in a singlet ground state. Treatment of Bu'C5H5Si(Bu')C1 with LiNPri2 has been used to generate 1,4-di-t- butylsilabenzene; its tricyclic dimer was the only isolated product but the silaben- zene was also trapped by 1,3-dienes as the Diels-Alder adduct."' Generation of a silacyclopentadiene (15)was attempted by thermolysis of Ph2C4H2Si(Me)(SiMe3).' l6 Again only a dimer was isolated but (15) was trapped as (16) by diphenylacetylene. '06 L. J. Turbini R. E. Aikman and R. J. Lagow J. Amer. Chem. SOC.,1979,101 5833. lo' L. A. Shimp and R. J. Lagow J. Amer. Chem. SOC..1979,101,2214. lo' G. Fraenkel A. M. Fraenkel M. J. Geckle and F.Schloss J. Amer. Chem. SOC.,1979,101,4745. '09 E. D. Jemmis J. Chandrasekhar and P. ton R. Schleyer J. Amer. Chem. SOC.,1979,101,2848. A. Bonny and S. R. Stobart J.C.S. Dalton 1979 786. G. Boche F. Heidenhain and B. Staudig Angew. Chem. Internat. Edn. 1979,18 218. A. Bonny and S. R. Stobart J. Amer. Chem. SOC.,1979,101,2247. 'I3 L. F. Brough K. Matsumura and R. West Angew. Chem. Internat. Edn. 1979,18 955. '14 T. J. Drahnak J. Michl and R. West J. Amer. Chem. SOC.,1979 101 5427. '" G. Mark1 and P. Hogmeister Angew. Chem. Internat. Edn. 1979,18 789. 'I6 T. J. Barton W. D. Wulff E. V. Arnold and J. Clardy J. Amer. Chem. SOC.,1979 101 2733. Organ om e tallic Chemistry (16),characterized crystallographically is the first stable 1-silanorbornadiene.Pho- tolysis of (Me,Si),SiC(O)Bu' has allowed observation of the silaethylene (17) by n.m.r.ll' This silaethylene is relatively stable but again could only be isolated as its dimer. The gas-phase reaction products from [MeMn(CO)S] and BH' depend upon the proton affinity of the base B."' If this is low the complex is protonated; otherwise methane is eliminated leaving [Mn(CO)5]'. A second protonation is considered necessary for the elimination process. Fe'(g) generated by electron impact on [Fe(CO)s] has been found to cleave C-H and C-C bonds in saturated hydro- carbon~,~~~ and also to undergo oxidative addition with alkyl halides."0 Co' and Ni' behave similarly but Li' and Na' cause dehydrohalogenation of the alkyl halide. Low-temperature co-deposition of metal vapours and excess solvent forms active metal powders in a slurry form with good shelf lives."' These readily react with alkyl or aryl halides to form metal alkyls e.g.R,PbX RzZn RCdX or in the case of nickel organic products. Observation of the Fe/C& matrix system at 20 K by 57Fe Mossbauer and i.r. spectroscopy has indicated a species containing Fe-H bonds.122 This may be due to oxidative addition of methane. H2 and isobutane also seem to undergo oxidative addition on to the Fe atoms. Co-condensation of zirconium vapour and isobutane or neopentane at 77 K forms a black solid which may also contain metal alkyls and hydrides." Hydrolysis of the neopentane-derived material generated mainly H2 and C5H12 and some methane and isobutane possibly from [HZr(CH2Bu')] and [MeZr(C,H,)] respectively.The uranium-alkyl bond in [(C5Me5)2U(R)C1] is readily hydrogenolysed to form the alkane and [(C5Me5)2UC1]3.124 The chloride-bridged trimer reacts with LiCH(SiMe,) to form [(C5Me5)2UCH(SiMe,)z] and yields a metallacyclopentadiene complex [(C,Me,),U(CPhCPhCPhCPh)] on treatment with diphenylacetylene. Complexes of the type [(C5H5),MMeI2 (M =Y Dy Ho Er Tm or Yb) have been prepared by reaction of [(CSH5)2MMe2AlMe2] X-Ray structure and ~yridine.'~~ determinations of the yttrium and ytterbium dimers have shown that there are two bridging methyl groups very similar in geometry to those in A12Me6. 117 A. G. Brook J. W. Harris J. Lennon and M. El Sheikh J. Amer. Chem. SOC., 1979,101 83. 118 A.F. Stevens and J. L. Beauchamp J. Amer. Chem. SOC.,1979,101,245. 119 J. Allison R. B. Freas and D. P. Ridge J. Amer. Chem. SOC.,1979,101 1332. 120 J. Allison and D. P. Ridge J. Amer. Chem. SOC.,1979 101,4998. 121 K. J. Klabunde and T. 0.Murdock J. Org. Chem. 1979,44,3901. 122 P. H. Barrett M. Pasternack and R. G. Pearson. J. Amer. Chem. SOC.,1979,101,222. 123 R. J. Remick T. A. Asunta and P. S. Skell J. Amer. Chem. SOC.,1979,101 1320. 124 J. M. Manriques P. J. Fagan T. J. Marks S. H. VolImer.C. S. Day and V. W. Day J. Amer. Chem. SOC. 1979,101,5075. 125 J. Holton M. F. Lappert D. G. H. Ballard R. Pearce J. L. Atwood and W. E. Hunter J.C.S. Dalton 1979,45 54. A. J. Deeming and J. Evans The crystal structure of o-anisylcopper has been reported.'26 It is an octamer with a square antiprismatic array of copper atoms.The anisyl ligands bridge the eight triangular faces. 'H and 13C n.m.r. measurements on the dimeric Cu Ag and Au complexes (18)have demonstrated several exchange processes including the rotation of the bridging aryl group^.'^' M M Methylcyclohexane is eliminated when [(C5H5),Zr(H)(CH2Cy)]is treated with a phosphine.''* The zirconium(I1) complexes produced e.g. [(C5H5)2Zr(PPh2Me)2] undergo unusually rapid oxidative addition-substitution reactions to form [(C,H,),Zr(R)(X)]. [(C5H5)2Zr(tolyl)(OPri)] is isolated from a solution of the Zr" phosphine in a toluene-acetone mixture. The initial product may involve oxidative addition of an aryl C-H bond.Zirconium alkyls and aryls of the type [(C5H5)2ZrH(R)] (R = alkyl or acyl) readily undergo transalkylation reactions with AlCl to form RAlC12.'29 This has allowed the preparation of the first acyl- aluminiums. These have a low vco at 1550cm-' indicating either an qz or a C-0 bridging co-ordination of the acyl group. Transalkenations from SnMe3(CPh=CMez) to early transition-metal halides has provided a route to alkenyl complexes including the first scandium alkenyl complex [SCC~~(CP~=CM~,)].THF.'~~ Sodium naphthenide reduction of [(C5H4R')2MR22] (M = Ti Zr or Hf) has yielded the corresponding d' anions identified by e.s.r.13' Paramagnetic alkyl complexes have been stabilized using a chelating benzyl or phenyl ligand.'j2 Thus treatment of [(C5H5)2MCl] (M = Sc Ti or V) with LiCH2- (o-NMe2C6]H4)and Li(o- CH2NMe2C6&) has afforded the appropriate metallocy- clic [(C5H5),hh(C-fi)] species.Both lithium reagents react with [(C5HS)TiCl2] to form [(C&)2m)2. The phenyl derivative has been characterized crystallo- graphically and it reacts with CO to form (19). WMe6 TaMe5 and NbMe5 all form seven-co-ordinate adducts with PMe which are more stable than the binary alkyl~.'~~ The tungsten complex eliminates methane on heating to form tran~-[WMe~(PMe~)~]. Metallation of [(C5H5),ReH] with BuLi A. Camus N. Marsich G. Nardin and L. Randaccio J. Organometallic Chem. 1979,174 121. G. van Koten and J. G. Noltes J. Amer. Chem. SOC.,1979 101 6593. K. I. Gel1 and J. Schwartz J.C.S. Chem. Comm. 1979,244. D.B. Carr and J. Schwartz J. Amer. Chem. SOC.,1979,101,3521. D. J. Cardin and R. J. Norton J.C.S. Chem. Comm. 1979 513. M. F. Lappert P. R. Riley and P. I. W. Yarrow J.C.S. Chem. Comm. 1979 305. 132 L. E. Manzer J. Amer. Chem. SOC.,1978,100,8068. 133 R. A. Jones G. Wilkinson A. M. R. Galas and M. B. Hursthouse J.C.S. Chem. Comm. 1979,926. 12' 12' 207 Organometallic Chemistry GHS) i N Me (19) yields the useful synthetic intermediate [(CSH,)2Re]Li which can be alkylated on the Aerial oxidation of [Me4ReO] or [Me3Re02] has yielded [MeReO,] which was shown to have C3"symmetry by i.r. and Raman rneasurement~.'~~ Na[Mn(CO)S] reacts with ClCH20R (R = COBu') to form the pivalolyl ester of a hydroxymethyl complex [(C0)5Mn(CH20R)].'36 High-pressure hydrogenation yields HOCH2CH20R and HC(0)CH20R but CO inhibits the production of glycol derivatives.An alkyl migration process to give [(C0)4Mn(CO)(CH20R)] was thought to be the first reaction step. Under H2 at 1atm pressure CH30R is the major product. Methylation of [(CSHs)Fe(CO)2(CH2SMe)] with Me30BF4 affords [(C5Hs)Fe(C0)2(CH2SMe2)]BF4 as a stable isolable The salt acts as a methylene transfer agent converting olefins into cyclopropanes. The first Group VIII diazoalkyl complexes have been synthesized for palladium using LiC(N2)R or Hg[C(N2)R]2.138 A crystallographic study of tran~-[Pd(PPh~)~(C(N~)Co~Et}~] showed Pd-C C-N and N-N bond lengths of 201.0 127 and 117 pm respec- tively. [C7H7Re(CO),] has been synthesized by two r0~tes.l~' Spin saturation transfer studies in the 25-37 "C range demonstrated 1,2 metallotropic shifts as opposed to the 1,s shifts observed for C7H7SnPh3.[(q5-CsHs)(77 '-C5H5)Pd(PR3)] derivatives have been shown to undergo two exchange proces~es.'~~ At low temperatures there is migration about the ql-ring but a higher-energy process causes q'-q5 exchange. The rate of this process is highly dependent upon the phosphine (rate order ?Me3>PPhJ>PPr',). Oxidative addition of aryl C-H bonds occurs readily on [HFe(N~)(dmpe)~].'~' The stability of the aryl hydrido-complex in equation (8)is enhanced by electron- withdrawing substituents in the aryl group. Activation of aldehyde C-H bonds has [HFe(Np)(drnpe)z]+ArH $ [HFe(Ar)(dmpe)z]+HNp (8) also been achieved.'42 For example reaction of PPh2(oY CHOC6H4) and Vaska's compound gives rise to the metallated Ir"' complex [HIr{C(0)C6H4PPh2}Cl(CO)-(PPh,)].A similar reaction occurs between [(PPh3)3RhCl] and (20) to form (21).143 D. Baudry and M. Ephritikhine J.C.S. Chem. Comm. 1979,895. I. R. Beattie and P. J. Jones Znorg. Chem. 1979 18 2318. 136 D. B. Dombek J. Amer. Chem. SOC.,1979,101,6466. 13' S. Brandt and P. Helquist J. Amer. Chem. SOC.,1979,101,6475. S.-I. Murahashi Y. Kitani T. Hosokawa K. Miki and N. Kasai J.C.S. Chem. Comm. 1979 450. D. M. Heinekey and W. A. G. Graham J. Amer. Chem. SOC.,1979,101,6115. I4O H. Werner and H.-J. Kraus Angew. Chem. Internat. Edn. 1979,18,948. C. A. Tolman S. D. Ittel A. D. English and J. P. Jesson J. Amer. Chem.SOC.,1979 101 1742. 14' T. B. Rauchfuss J. Amer. Chem. SOC.,1979,101 1045. 143 J. W. Suggs J. Amer. Chem. SOC.,1979,101 489. A.J. Deeming and J. Evans H"Ph The rhodium(1) complex evidently is a precursor to a catalyst for adding the imine C-H bond across the double bond in ethylene. Hydrolysis after reaction between (20) and ethylene (150 psi 160 "C 6 h) in the presence of [(PPh3),RhC1] yielded a 900% yield of PhCOEt based on rhodium. Evidence for a rapid olefin-insertion p-hydride elimination sequence has been obtained by n.m.r. observation on [(C5H5)Rh(H)(C2H4)PMe3]BF4.'44 At -20 "C sharp hydride and ethylene proton resonances are observable but they broaden at room temperature indicating an exchange process probably uia the Rh-Et complex.Addition of either halide anions or ethylene drives the equilibrium to an insertion product. The square-pyramidal complex (22)has been shown to undergo a rapid exchange process between the hydride and a-C-H proton (R = H) at room temperat~re.'~~ The hydride resonance could not be observed at room temperature. However a 1H[31P,'03Rh] INDOR experiment gave the Io3Rh resonance as a triplet coupled to two protons considered to be the averaged hydride and a-C-H proton sites. U -R 0 CH3 (22) (23) Catalysis of ethylene hydroformylation by mononuclear rhodium carbonyl complex precursors has been monitored in a high-pressure i.r. cell.'46 vco absorp-tions attributable to [EtRh(CO),] are observed under the reaction conditions. [(C5Me,)TaMe4] reacts with CO at -78 "C to form a species exhibiting a vco band near 1200 cm-' and thought to be an q*-acetone complex [(C5Me5)TaMe2- (q2-OCMe2)].'47 The Ta-C bond of the acetone complex is cleaved by hydrogen to form [(C5Me5)TaMe2(H)(OPri)],and at room temperature a further series of insertions yields the Ta-0-(CMe)=CMe2 moiety by an intramolecular process.AlBr3 has been shown to favour methyl migration to form acyl complexes.148 (23) was isolated from the reaction with [MeMn(CO)J and character-ized crystallographically. The Mn-Br bond is cleaved by CO to form 144 H. Werner and R. Feser Angew. Chem. Internat. Edn. 1979,18,157. C. Crocker R. J. Errington W. S. McDonald K. J. Odell B. L. Shaw and R. J. Goodfellow J.C.S. Chem. Comm. 1979,498. 146 R.B. King A. D. King jun. and M. Z. Iqbal J. Amer. Chem. SOC.,1979,101,4893. '47 C.D.Wood and R. R. Schrock J. Amer. Chem. SOC.,1979,101,5421. 14* S.B. Butts E. M. Holt S. H. Strauss N. W. Alcock R. E. Stimson and D. F. Schriver J. Amer. Chem. SOC.,1979,101,5864. 14' Organometallic Chemistry 209 [(CO)5MnC(Me)(OA1Br3)]; [(C5H5>Mo(CO),Me] behaves similarly. The Lewis acids BF3 and SbF5 have also been shown to accelerate SO insertion into [(C5H5)W(CO),R] (R = Me or CH2Ph).14' [(C,H5)W(C0),{0S(0EF,)R}] adducts are isolated (E = B or Sb) which collapse to the S-sulphinite on treatment with NH3 or aniline. For BF3 the acceleration is some 20 000 times and is due to the greater electrophilicity of the SO,-BF adduct. Last year's proposal that the Zeigler-Natta polymerization is propagated via a-hydrogen elimination and a metal carbene complex has been tested on reaction (9):'" +C2H4 + [(C5H5>Co(C2H4)(PPh3)] [(C5H5)CoMe2(PPh3)] +CH4+MeCH=CH (9) Labelling experiments demonstrated that methane was derived from a Co-CH group and one proton from ethylene and also that a complete Co-CH3 group was transferred to ethylene to form propene.This is consistent with ethylene insertion into a Co-CH3 bond followed by p-hydrogen abstraction rather than a-hydrogen abstraction from a Co-CH3 moiety. Insertion of diphenylacetylene into the Ni-CH3 and in [Ni(acac)(Me)(PPh,)] gives an apparent trans-addition product [Ni(acac)(CPh=CPhMe)(PPh,)]. lS1 The same product is formed from [Ni(acac)- (Ph)(PPh,)] and PhCECMe so they appear to share a common intermediate.cis- Addition across the acetylene is considered to occur. PPh catalyses the reaction and ligand addition to the @carbon is thought to allow rotation about the carbon- carbon double bond. Reductive elimination of MeCl from [Rh(Me)Cl,(CO)(PPh,),] has been shown to be a first-order intramolecular process.152 However PPh accelerates the elimina- tion forming [MePPhJCl by an apparent SN2 attack on the co-ordinated methyl group. Carbonylation of [(pC0)2{(C5H5)(R)Co}2] (R = Me or Et) at 25 "C causes elimination of a ketone RCOR with [(C5H5)Co(CO)2] as the organo- metallic [(C5H5)Co(CO)Me2]was detected by n.m.r. at 35 "C but at lower temperatures a different mechanism can also give rise to ketones.[(p-CO)2{(C5H5)2Co(COMe)2}2] was obtained as unstable brown solid; this also decomposes to acetone but not via the Co"' dimethyl complex. The critical species is probably a [(C5H5)Co(CO)(COMe)] monomer. This process has been further investigated using the linked cyclopentadienyl dimer (24).ls4 Carbonylation of (24) at 70°C yields acetone by both intra- and inter-molecular processes the former being favoured by dilute solutions. PPh promotes methyl transfer at 25 "C to form (25) (Scheme 2) and this type of process may be important in the intramolecular pathway. Elimination of acetaldehyde from [(C5H5)Mo(CO),H] and [(CSH5)Mo(CO),Me] follows second-order kinetics; [(C5H5)2Mo(CO),] (n =4 or 6) are also formed.155 Evidence obtained militates against a radical process.Methyl migration is thought to form a co-ordinatively unsaturated acyl complex which may form a bimolecular adduct with the hydride prior to acetaldehyde elimination. 149 R. G. Severson and A. Wojcicki J. Amer. Chem. SOC. 1979,101 877. I5O E. R. Evitt and R. G. Bergman J. Amer. Chem. SOC.,1979 101 3973. "' J. M. Huggins and R. G. Bergman J. Amer. Chem. SOC. 1979,101,4410. 152 E. L. Weinberg and M. C. Baird J. Organometallic Chem. 1979 179 C61. M. A. White and R. G. Bergman J.C.S. Chem. Comm. 1979 1056. lS4 H. E. Bryndza and R. G. Bergman J. Amer. Chem. Soc. 1979,101,4766. Is' W. D. Jones and R. G. Bergman J. Amer. Chem. SOC. 1979,101,5447. A. J. Deeming and J. Evans PPh, 25 "C CO co(CO)z Ph,P' I'CH3 CH3 There has been an extensive mechanistic study on the reaction between truns-[ArNiX(PEt3),] and Ar'X to form biar~1s.l'~ After an initial electron transfer from the nickel complex to the aryl halide a radical chain mechanism was established involving Ni' and ArNi'I'Ar' complexes.Coupling of the related palladium alkyl complexes [RPdX(PPh3)2] with SnR4 or R'MgX to form R-R has also been st~died."~ [(PhCH2)PdBr(PPh3)2] reacts with the main-group alkyl eventually forming R'CH,Ph with retention of configuration at the benzyl a-carbon. cis-[Me2Pd(PPh3)2] couples with PhCH2Br to form ethylbenzene and [MePdBr(PPh,),]. No ethane is formed under these conditions and PhCH2Br oxidative addition is thought to produce a Pd'" intermediate. The orbital symmetry requirements for the reductive elimination of a metallo- cyclopentane have been ~0nsidered.l~~ For a d6species generating a square-planar complex by elimination of R'-R2 is allowed if the LML angle is opened but not if the L' ligands move towards the alkyl groups (Scheme 3).Thus whereas cis-[P~(PBu~)~( C4H8) (CI)(CH2C1)] yields cyclobutane the dmpe derivative only forms Cs open-chain products. Furthermore cyclobutane and ethylene elimination were shown to be allowed for [L,Ni(CdH8)] and [L3Ni(C4H8)] systems respectively in accord with last year's reports. L' L' + M /= + /R' RZ 4I L L' L' ,L\M /L'+ 4R' R2 L 4 kL1 Scheme 3 15' T. T. Tsou and J. K. Kochi J. Amer. Chem. SOC.,1979,101,7547. 157 D.Milstein and J. K. Stille J. Amer. Chem. SOC.,1979 101 4981.lS8 P.S.Braterman J.C.S. Chem. Comm. 1979 70. Organometallic Chemistry 211 Metallaindan complexes e.g. [(c5H5)2zr(cH2cH2c6H4)], have been synthesized by pyrolysis of [(C5Hs)2ZrPh2] in the presence of the appropriate olefin."' Olefin exchange occurs with more active olefins to form new metallaindan derivatives but the initial rate is independent of the added olefin. A slow reductive decoupling to a benzyne-olefin complex is probably rate determining. The olefin complexes [(C,Me,)TaC12(CH2=CHR)] have been shown to be in equilibrium with their metallacyclopentanes [(C,Me5)TaC12(CH2CHRCHRCH2)],160 two of which have been examined crystallographically.161[(C,Me5)Tk12(CH2CH2CH2CH2)]was shown to decompose to butene uia a p-hydride elimination process.These systems catalyse olefin dimerization and this was studied using 2-deuteriopent-1-ene as substrate.162 Although the major [2H2]decene produced could be rationalized uia oxidative coupling to form a metallacyclopentane followed by 6-hydride elimina- tion the minor isomer obtained was unexpected. A ring-contraction process Scheme 4 was proposed to account for this product. Further evidence for the ring contraction was obtained using a mixed propylene-2-deuteriopent-1-ene system. M&+\& D D M = (C,Me,)TaCl Scheme 4 Insertion of a rhodium atom and a Rh-CO group into tetrachlorocyclopro- pene occurs in reaction with [Rh(CO)C1(PMe2Ph)2].163 A rhodacyclobutadiene complex [Rh(CO)C1(PMe2Ph),(C3Cl3)]Cl, and a rhodacyclopentadienone [RhC12(CC1CCICClCO(PMe2Ph)2], are formed.Neopentane is eliminated in the pyrolysis of cis -[Pt(PEt3)2(CH2Bu')2], leaving a platinacyclobutane complex [Pt(CH2CMe2kH2)(PEt3)2,164 Kinetic measurements are consistent with initial phosphine loss in a pre-equilibrium and a rate-determining y-hydrogen elimination. An activation energy of ca.205 kJ mol-1 was estimated for the cleavage of this unactivated C-H bond. Isomerization reactions e.g. Scheme 5 have again received attention. The reaction is retarded by extra ligand e.g.pyridine so ligand dissociation was shown to precede the uncoupling of the platinacyclobutane to form a carbene-olefin complex.16s Using the deuteriated derivative in Scheme 5 it was established that the positional isomerization of the phenyl group did not alter 159 G.Erker and K. Kropp J. Amer. Chem. SOC.,1979,101,3659. 160 S.J. McLain C. D. Wood and R. R. Schrock J. Amer. Chem. SOC.,1979,101,4558. M. R. Churchill and W. J. Youngs J. Amer. Chem. SOC.,1979,101,6462. 162 S.J. McLain J. Sancho and R. R. Schrock J. Amer. Chem. SOC.,1979,101,5451. 163 P. D.Frisch and G. P. Khare J. Amer. Chem. SOC.,1978,100,8267. P. Foley and G.M. Whitesides J. Amer. Chem. SOC.,1979,101,2732. 16' P. J. Al-Essa R. J. Puddephatt. M. A. Quyser and C. F. H. Tipper J. Amer. Chem. SOC.,1979,101,364. A. J. Deeming and J. Evans Scheme 5 the relative stereochemistry of the phenyl and deuterium substituents. 166*167 This militates against a long-lived olefin-carbene intermediate since rotation about the Pt-carbene bond would destroy this stereochemical integrity.A variety of mechanisms were proposed although the disrotatory motion shown in Scheme 5 is appealing. Thermolysis of [Pk12py2( CMe2CHMeCH2>] liberates 2,3-dimethylbut- 1-ene.16’ Deuteriation studies demonstrated that.both types of p-hydride elimina- tion occurred although abstraction of the ring proton was favoured. There has been great interest in the chemistry of [(C,H,)Re(NO)-(CO)(CHO)].’69”-”2Some of the reported chemistry is presented in Scheme 6. The reduction products from [(C5HS)Re(NO)(C0)2]+ are highly dependent upon the conditions but stepwise reduction from M-CO to M-CH3 has been demonstrated. 9-’+ [H-] dilute -Zz+ Re Re Re 0” po ON/ \‘CHO ON’ \‘H C 0 C 0 O YOi’ bH-I p-I Q PN0 Re 0 Re’ [H-I t ON’I k& ‘C’ C II Re Re 0 ON/ \‘CH3 C 0” LY20H 0 0 Scheme 6 The formyl complex is unstable either decarbonylating to a hydride in dilute solution or disproportionating as a neat oil.Addition of LiBHEt to [OS,(CO)~~] and [Ir4(CO)12] gives rise to transient formyls prior to decomposition to metal hydride anions.173[(C,H,)Re(NO)(PPh,)(CHO)] is the first formyl complex to be charac- terized crystallographically (-160 On the evidence of a short Re-C bond 166 R. J. AI-Essa R. J. Pudephatt M. A. Quyser and C. F. H. Tipper Inorg. Chim. Acta 1979,34 L187. 167 C. P.Casey D. M. Scheck and A. J. Shusterman J. Amer. Chem. SOC.,1979,101 4233. T. H. Johnson and S. S.Cheng J. Amer. Chem. SOC. 1979,101,5277. 169 C. P. Casey M. A. Andrews and J. E. Rinz J. Amer. Chem. SOC. 1979,101,741. 170 W. Tam W.-K. Wong and J. A. Gladysz J. Amer. Chem. SOC.,1979,101 1589. 17‘ J. R. Sweet and W. A. G. Graham I. Organometallic Chem. 1979,173 C9. 17‘ C. P.Casey M. A. Andrews and D. R. McAlister J. Amer. Chem. SOC. 1979,101,3371. 17’ R. L.Pruett R. C. Schoening J. L. Vidal and R. A. Fiato J. Organometallic Chem. 1979,182 C57. 17‘ W.-K. Wong W. Tam C.E. Strouse and J. A. Gladysz J.C.S. Chem. Comm. 1979,530. Organometallic Chemistry 213 (205.5 pm) and a low vco (1558 cm-') it is thought to have much Re+=C(O-)H character. Addition of MeS03F at -78 "C causes this complex to disproportionate to [(C5H5)Re(NO)(PPh3)(CO)]+and [(C5H5)Re(NO)(PPh3)(CH3)].Further 175 studies identified several possible intermediates shown in Scheme 7. Hydride abstraction from [(C5H5)Re(NO)(PPh3)(CH3)]began a sequence including Re=CH2 Re-CH20Me and ReCHOMe moieties. Formaldehyde binds to [Os(CO),(PPh,),] forming an q *-ligand in [OS(CO)~(PP~~)~(CH,O)], characterized crystallographically.'76 C-H bond cleavage occurs in the solid at 25"C to form a hydrido-formyl complex [HOS(CHO)(CO),(PP~,)~], which in turn loses H2 above 40 "C leaving [OS(CO),(PP~~)~] as the final product. A crystal structure determination on trans-[C~(dmgH)~(Pr')py] has shown the presence of a long Co-C bond (208.5pm).'77 Adding substituents to the co- ordinated carbon was shown to increase the Co-C separation. The rate and equilibrium constants for equation (10) have been measured.'78 The Co-C bond strength was estimated as 83 kJmol-' and the activation enthalpy was consistent [(py)C~(dmgH)~CHPhMe] [(py)C~(dmgH)~] +PhCHCH2+iH2 (10) with a rate-determining homolysis step.Flash photolysis has been used to monitor the photochemistry of methyl- and adenosyl-cobalamin.'79 These results indicated that homolysis occurred without intermediacy of a long-lived excited state and this reversed after -lov4s. 4 Carbenes and Carbynes The heat of formation of Me2SiCH2 has been estimated by studying the reaction between SiMe3' and various bases using ion cyclotron resonance spectroscopy.'80 A value of -86 kJ mol-1 was obtained and this indicates a r-bond energy of 17' W.-K.Wong,W. Tam and J. A. Gladysz J. Amer. Chem. SOC.,1979 101,5440. 176 K. L. Brown G. R. Clark C. E. L. Headford K. Marsden and W. R. Roper J. Amer. Chem. SOC.,1979 101,503. 177 L.G. Marzilli P. J. Toscano L. Randaccio N. Bresciani-Pahor and M. Calligaris,J. Amer. Chem. SOC. 1979,101,6754. 17' J. Halpern F. T. T. Ng and G. L. Rempel J. Amer. Chem. SOC.,1979 101 7124. 179 J. F.Endicott and T. L. Netzel J. Amer. Chem. SOC.,1979,101,4000. W. J. Pietro S. K. Pollack and W. J. Hehre J. Amer. Chem. SOC.,1979 101 7126. 214 A. J. Deeming and J. Evans -142 kJ mol-'. SF4CH2 has been characterized by a number of techniques.'81 The S-C bond (1.55 pm) is in an equatorial site of a trigonal bipyramid with the CH2 group in plane with the axial fluorine atoms.Other notable features are the high vCH frequencies (bl 3210 cm-' al 3092 cm-') and the high ionization potential of the ncsorbital. This is 10.65 eV as compared with -7 eV in phosphorus ylides. The Mn-CH2 bond energy has been estimated as 385-418 kJ mol-' in MnCH2+.lE2 In [Mn(CO),CH2]+ this value was markedly lower (322 kJ mol-') and this was related to their different reactions with olefins in the- gas phase. Methylene addition competed with metathesis in the former case only. Generally it was thought that a metal-carbene bond strength of >418 kJ mol-' was necessary for metathesis to compete with cyclopropanation. Addition of one mole of HBF4 to [{(PMe3)3R~}2(p-CH2)3] generates a bridging methyl group in [{(PMe3)3R~}2(p-CH2)2(pCH3)]BF4.183 This causes a lengthening of the Ru-Ru distance from 265.0 to 273.2pm.Methane is eliminated when a second mole of the acid is added to form the dicationic complex [{PMe3)3- p -CH2)2](BF4)2. Ru}~( This cation contains a planar Ru-C-Ru-C unit (Ru-C 207.1 pm Ru-Ru 264.1 pm) joining two square-pyramidally co-ordinated ru- thenium centres. Hydride abstraction from [(C5H,)Fe(CO)L(CH20R)] (L = CO or PPh,; R = Me or Et) by CPh3PF6 has afforded the alkoxy-carbene cations [(C,H,)Fe(CO)L(CHOR)]PF6.184 Attempted oxygen dealkylation to form a formyl complex led to [(C5H5)Fe(CO)2L]+ and [(C,H,)Fe(CO)L(CH20R)]. Borohydride reduction of the carbene also gave two types of product viz. the alkoxy-methyl complex and [(C5H5)Fe(CO)L(CH3)]. The carbene complex [(CO),Cr(CNEt,)SnPh,}] has been found to rearrange into a carbyne tran&[Cr(SnPh3)(CNEt2)(CO)4], at room temperature both in the crystal and in s01ution.l~~ In this example the migrating group is SnPh3.Unlike the previously reported cases [(CO),Cr((CNEt,)X}] (X = C1 Br or I) the migrating group does not possess a lone pair which had been thought necessary. Reactions of [Sn(TPP)C12] and SnPcCl with [Re2(CO)lo] at 180 "C have afforded trans-[{Re(CO),},SnL] (L = TPP or Pc).lg6 However at 160 "C the tetraphenylporphyrin complex gives rise to (26). The unusual carbon atom site in (26) between two metal atoms has bond lengths of 175 and 214 pm to rhenium and tin respectively and was thus considered to be a carbyne complex of rhenium. The crystal structure of [W(CBu')(CHBu')(CH2Bu')(dmpe)](27) has been rep~rted.'~' This five-co-ordinate complex possess alkyl carbene and carbyne ligands in a square-pyramidal geometry.The W-C single double and triple bond lengths are 225.8,194.2,and 178.5 pm respectively. A neutron diffraction study on H. Bock J. E. Boggs G.Kleemann D. Lentz H. Oberhammer E. M. Peters K. Seppelt A. Simon and B. Solouki Angew. Chem. Internat. Edn. 1979 18 944; S. Sunder H. H. Eysel G. Kleernan and K. Seppelt Inorg. Chem. 1979 11 3208. A. E. Stevens and J. L. Beauchamp J. Amer. Chem. SOC.,1979,101,6449. '" M. B. Hursthouse R. A. Jones K. M. Abdul Malik and G. Wilkinson J. Amer. Chem. SOC.,1979,101 4128. A. R. Cutler J. Amer. Chem. SOC., 1979,101,604. E. 0.Fischer H. Fischer U.Schubert and R. B. A. Pardy Angew. Chem. Internat. Edn. 1979,18,871. S. Kato I. Noda M. Mizuta and Y. Itoh Angew. Chem. Znrernar. Edn. 1979,18,82; B. I. Noda S. Kato M. Mizuta N. Yasuoka and N. Kasai ibid.,p. 83. M. R. Churchill and W. J. Youngs J.C.S. Chem. Comm. 1979 321; Inorg. Chem. 1979,18,2454. Organometaliic Chemistry 215 But C rlIlyPMe2 Me2P-w @\ I Bu'-c 1 CH2Bu' (Oc),ReNC H (26) (27) [(p-C1)2{TaC12(PMe3)(CHBu')}] has focused attention on the geometry of the carbene atom.'" This complex provides another example of a wide CCTa angle (161.2') and also an unusually long C-H distance (113.1 pm). Further evidence for activation of this C-H bond comes from spectroscopic measurements on [(C5R5)TaC12CHBut] (R=H or Me) formed in the decomposition of cis-[(C5R5)TaC12(CH2Bu')2].189 These moieties have low 'JCHvalues of 75-85 Hz and also a low vCH(-2500 cm-').Diphenylacetylene and organic nitriles (MeCN and PhCN) were found to insert into the Ta=CH%;' bond. This low vCHhas also been observed on the Phillips olefin polymerizatiorkatalyst of chromia on silica which has surface Cr" sites.'" The working catalyst exhibited a vOHbond at 3720 cm-' and a weak broad vCHat 2750 cm-' indicating a surface hydroxy-group and perhaps also a carbene-bound polymer chain. Both these bands were lost when the catalyst was exposed to CO and this was rationalized on the basis of Scheme 8. The degenerate RH I H 'C' co H-C-H I I II -R 77777;9e!m ~ ~ ? Scheme 8 metathesis reaction in equation (1 1) has been ob~erved.'~' [(CSH~)ZT~CH~AICIM~~] +CH2CMe2 (1 1) +13CH2CMe2 $ [(C5H5)2Ti13CH2AlClMe2] The bridging methylene unit and the isobutene methylene group were found to exchange as a unit and the (C5H5),TiCH2 moiety was considered to be the active species.If the olefin has hydrogen atoms on both ends then another pathway involving p-hydride elimination from a metallacyclobutane yields CH2=CRMe instead of the metathesis product. Protonation of [(CO)SW{CH(OMe)Ph}]-at -78 "C has afforded [(CO),W(CHPh)] as an unstable species (ti 24 min at -56 OC).19' The carbene proton was found to resonate at 17.256. HCECOEt inserts into the tungsten-carbene A. J. Schultz J. M. Williams R. R. Schrock G. A. Rupprecht and J. D. Fellmann J. Amer.Chem. SOC. 1979,101,1593. C. D. Wood S. J. McLain and R. R. Schrock J. Amer. Chem. SOC.,1979,101 3210. G. Ghiotti E. Garrone S. Coluccia C. Morterra and A. Zecchina J.C.S. Chem. Comm. 1979 1032. 19' F. N. Tebbe G. W. Parshall and D. W. Ovenall J. Amer. Chem. SOC.,1979 101 5074. 192 C. P. Casey S. W. Polichnowski A. J. Shusterman and C. R. Jones J. Amer. Chem. SOC.,1979 101 7232. A. J. Deeming and J. Evans bond to form [(CO),W{C(OEt)(CH=CHPh)}] probably uia a metallacyclobutene intermediate [(CO),W{CPhHCHC(OEt)}]. No metathesis products were observed when the phenylcarbene complex interacted with alkenes; phenylcyclopropanes were formed instead. Syntheses and reactions of the vinylidene complexes [(C,H,)L2M(C=CR'R')]' [M =Fe Ru or Os L2= (PPh3)' dppe or dppm R' or R2 = Me Et H or Ph] have been reported.193*194 These complexes possess a 13C resonance at -3608 due to the co-ordinated carbon atom. Protonation of the acetylide complexes [(C5H5)ML2(C=CR)] yields the [(C5H5)ML2(C=CHR)]+ cations and this process is reversed by bases. Bases react quite differently with [(CSH5)Fe(dppe)-(C=CMe2)]+.194 A proton is abstracted from the diphosphine backbone and a subsequent rearrangement yields (28) characterized crystallographically. Me Me 'C' [(CSMe5)2ZrH2] has been found to reduce the CO ligands in [(C,H,),M(CO)] (M=Cr Mo or W) and [(C5H5)2Nb(H)(C0)] to form the zirconoxycarbene complexes [(C,H,)2M{C(H)OZr(H)(C5Me,),)l and [(C,H,),(H)Nb{C(H)OZr(H)-(C5Mes)z}].19s The metal-carbene bond of both types of complex is cleaved by hydrogen to form [(CSMe5)2Zr(H)(OMe)] and e.g.[(C5Hs)2WH2].A step in the conversion of a M-CO ligand into a Zr-OMe group was identified in the reaction of [(C,H5)2(H)Nb{C(H)OZr(H)(CSMes)2}] with CO at 25 "C. Hydrogen transfer from Nb to C occurred to yield [(C,H,)2(CO)Nb{CH20Zr(H)(CsMe5)2}]. Insertion of CO into a metal-carbyne bond has been observed in the reaction between [(C5H5)(C0)2M(CR)] (M= Mo or W) and PMe3.196 The ql-ketenyl complex was found to be in equilibrium with an q2-species as in equation (12). CO transfer to a carbene ligand has also been observed in the reaction between [(CSHS)(C~)(PM~,)~M{C(CO)R)I C [(C,H,)(CO)M(77'-0CCR)] +PMe3 (12) (PPN)[Mn(CO),] and [(C5H5)(CO)zM{C(p-tolyl)}]BF4= Mn or Re).19' (M [MnM{C(p-tolyl)}(CO),(C,H,)] complexes were obtained and an X-ray diffraction study on the dimanganese species revealed structure (29) which possesses a bridging ketenyl ligand.Carbene addition to a metal carbonyl has been observed in the reaction between [(C,H,R)Mn(CO),(THF)] and [C6H4C(0)C6H4c(N2)].198 The product (30) was identified crystallographically. A series of experiments 193 M. I. Bruce and R. C. Wallis Austral. J. Chem. 1979,32 1471; M. I. Bruce A. G. Swincer and R. C. Wallis J. Organometallic Chem. 1979 171 C5. 194 R. D. Adams A. Davison and J. P. Selegue J. Amer. Chem. SOC.,1979,101,7232. 19' 19' P. J. Wolczanski R. S. Threlkel and J. E. Bercaw J. Amer. Chem. Soc. 1979 101 218. 196 W. Uedelhoven K. Eberl and F. R. Kreissel Chem.Ber. 1979 112 3376. 197 J. Martin-Gil J. A. K. Howard R. Navarro and F. G. A. Stone J.C.S. Chem. Comm. 1979,1168. W. A. Herrmann J. Plank M. L. Ziegler and K. Weidenhammer J. Amer. Chem. Soc. 1979,101,3133. Organometallic Chemistry demonstrated that the [(C,H,R)Mn(CO),(carbene)] complex was formed first and an intermolecular transfer of the carbene occurred on to [(C5H4R)Mn(C0),] to produce the keten (30). (29) (30) The WGC moiety in [(C,H5)W(CO)2{C(p-tolyl)}]has been effectively used as a ligand to bind to ~1atinum.l~~ Thus the carbyne displaces ethylene from [(C1&)PtL,J (L= PMe3 or PPhMez) to form [(C5H5)(CO)2W{p-C(p- tolyl)}PtL2]. trans-[W(CO),Br{C( p-tolyl)}] behaves similarly. This procedure was extended to carbene substrates.200 Thus treatment of [M(CO),{C(OMe)R}] [Pt(C2H4),] and PMe afforded [(CO),&l{p-C(OMe)R}Pt(PMe,>,3(M = Cr Mo or W).Dinuclear complexes with bridging carbene ligands of the type (‘(C5H5)(CO)2-Mn{p-C(OMe)Ph}M(PMe,)2] (M =Ni Pd or Pt) were also synthesized from [(C5H5)Mn(C0),{C(OMe)Ph}]. However reaction of the dinuclear carbene [(CO)5MnMn(6CH2CH2CH20)(C0)4], [Pt(C2H4),] and PMe did not give the anticipated product. Instead two isomers of [(C0)5Mn(p -kCHCH2CH20-Pt(PMe3),] were obtained. The cyclic ligand has lost one proton from a @-carbon and is acting effectively as a carbene complexed to platinum and an olefin to manganese. Trinuclear heterometallic complexes have been synthesized by the reaction between [Pt(CzH4)z(PR3)] (Rj = But2Me or Cy3) and [(CO),M{C(OMe)Ph}] (M = Cr or W).’O1 Complexes of the type (31)were obtained.However the trinuclear Pt complexes [Pt,(PMe,){p- C(OMe)Ph}z( p -CO)] and [Pt3(PMe3)2{p- C(OMe)Ph},] were obtained from the reaction of [Pt(C2HJ2PMe3] and [(C5H5)(CO)2Mn{C(OMe)Ph}] and also from the decomposition of [(CO)5Cr{p-C(OMe)Ph}Pt(PMe3)2];these trimers are evidently more stable than some of the heterometallic complexes. Treatment of [(C5H5)(CO),Mn-{p-C(OMe)(p- tolyl)}Pt(PMe,),] with [Me,O]BF causes loss of Me20 to leave a carbyne complex [(C5H5)Mn(C0)2{p-C(P- The rhenium t~lyl)}Pt(PMe~)~]BF~.~~~ analogue behaves similarly and both reactions can be reversed by interaction with methoxide ion. This reverse reaction does not occur for [(PMe,)(CO),Cr(p- CPh)Pt(PMe3)2]BF4.Instead treatment with methoxide yields (32). 199 T. V. Ashworth J. A. K. Howard and F. G. A. Stone J.C.S. Chem. Comm. 1979,42. 200 T.V.Ashworth M. Berry J. A. K. Howard M. Laguna and F. G.A. Stone 9.C.S. Chem. Comm. 1979 43. 201 T.V.Ashworth M. Berry J. A. K. Howard i.Laguna and F.G.A. Stone J.C.S. Chem. Comm. 1979 45. 202 J. A. K. Howard J. C. Jeffery M. Laguna R. Navarro and F. G. A. Stone J.C.S. Chem. Comm. 1979 1170. A.J. Deeming and J. Evans A bridging carbene ligand is also formed by treating [(C0)5W{C(OEt)Me}] with first MeLi and then CF3C02H;203 [(p-CHCHCMe2){W(CO)4}2] is the product. Labelling studies demonstrated that one of the terminal methyl groups comes from the methyl-lithium but all other protons are from the original carbene methyl group.[( p -CO){p-CCHC(C5Hll)C(0)O}{Co(CO)3}2] has been found to react with halo- genoacetylenes to yield a dinuclear complex with two different bridging ligand~.~'~ The crystal structure of one of these (33)was determined. At 20°C [(p-SMe)2{Fe(CO)3}2] forms an adduct with C2F4 in which one CF2 group is bonded to each iron atom.205 This complex isomerizes to [(~-sMe)~- (p-CFCF3){Fe(C0)3}2] which possess a bridging fluorocarbene ligand. ThZ a-fluorine was abstracted by reaction with BF, and subsequent treatment with PMe allowed isolation of [(p-SMe)2Fe2(CO)3(PMe3)2(CCF3)]BF4, which probably contains a carbyne ligand. Evidence for acetylene cleavage and methathesis was obtained in a study of the reaction between [(C5H5)Co(CO)2] and Me,SiCrCSiMe,.206 One of the products (34)contains two face-bridging carbyne ligands.Although the CSiMe moiety may arise from simple cleavage the three-carbon chain in the other such ligand requires a more complex reaction sequence. SiMe, I I iii C I SiMe (33) (34) 203 J. Levisalles H. Rudler Y. Jeannin and F. Dahan J. Organometallic Chem. 1979 178 C8. 2M 1. T.Horvith G. PBlyi L. Markb and G. Andrietti J.C.S. Chem. Comm. 1979 1054. 205 J. J. Bonnet R. Mathieu R. Poilblanc and J. A. Ibers J. Amer. Chem. SOC. 1979,101,7487. 206 J. R.Fritch K. P. C. Vollhardt M. R. Thompson and V. W. Day J. Amer. Chem. SOC. 1979,101,2768.

ISSN:0260-1818    

DOI:10.1039/IC9797600190

出版商:RSC    

年代:1979

数据来源: RSC