ISSN:0260-1818    

DOI:10.1039/IC98380FX001

出版商:RSC    

年代:1983

数据来源: RSC

ISSN:0260-1818    

DOI:10.1039/IC98380BX003

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

3 Boron By A. J. WELCH Department of Chemistry University of Edinburgh Edinburgh EH9 3JJ 1 Introduction The plenary lectures of the Fifth International Symposium on Boron Chemistry held in Swansea in July 1983 have been published.’ Solid-phase reactions of amorphous a-,and P-B with C Si and O2 have been studied a-B having the greatest reactivity and affording boron carbide SiB4 and B60 all of which are isostructural with it2 A separate study3 compares the stabilities of a-B and B60 towards acidic and alkaline media. Ni,B3 Ni2B NiB and B70 are reported4 to be among the products obtained from the high-temperature reaction between BN and Ni. The bonding in B,,C2 has been investigated by band-structure calculations (the valence bands are flat in almost all directions in keeping with a low electrical conductivity) and by cluster cal~ulations.~ It is suggested that the carbon-rich phase BI2C3 is more stable if the icosahedra are B,,C and the intericosahedral chains C-B-C.ThB, and HfBI2have been synthesized at high pressures,6 and have been shown to be isostructural with cubic UBI2. The overall structure and metal atom distribution in y-AlB, is more complicated but recently has been reinvestigated by Higashi via single-crystal diffraction and molecular orbital (MO) calculation^.^ Higashi and Ito have also studied LiA1B14 by X-ray methods and report that the results of population analyses of the valence electrons suggest’ charge transfer from the metal atoms (Li0.7+ All.’+) to the icosahedral cage (B12)1.2- and more importantly intercage boron atoms BO.’-.The unit cell dimension of Sml-,B6 decreases linearly with increasing x within the range x = 0-0.1 but thereafter is constant indicating the existence of a two-phase regime in boron-rich samples. In contrast there is no real change in cell dimension for the lanthanum boride LaB to Lao,75B6.9 A new series of ternary ‘ Pure Appl. Chem. 1983 55 1387. ’ I. A. Bairamashvili D. Sh. Dzhobava G. I. Kalandadze Yu. I. Soloev A. M. Eristavi and G. P. Lornidze Izv. Akud. Nuuk SSSR Neorg. Muter. 1983 19 214. Ya. A. Ugai N. E. Solov’ev and V. S. Makarov Zh. Neorg. Khim. 1983 28 1334. D. M. Karpinos and S. P. Listovnichaya Izv. Akad. Nuuk SSSR Neorg. Muter. 1983 19,121I. D.R. Armstrong J. Bolland P. G. Perkins G.Will and A. Kirfel Actu Crystallogr. Sect. B 1983 39 324. J. F.Cannon and P. B. Farnsworth J. Less-Common Met. 1983 92,359. ’ I. Higashi J. Solid State Chem. 1983 47 333. * T. Ito and I. Higashi Actu Crystullogr. Sect. B 1983 39,239. Yu. B. Paderno and T. Lundstrom Actu Chem. Scund. Sect. A 1983 37,609. 19 A. J. Welch borides (MI -x Rh,y)Rh3B2 involving lanthanide elements (M) and rhodium has been synthesized and structurally and magnetically studied." All have structures based on CeCo,B,. (Mn,-,M,)B species (M = Cr or Mo) were reported last year and now the same group of workers has expanded the range to include M = Ta and M = W derivatives." Within the homogeneity ranges studied all these species have Ta,B,-type structures. The competitive synthesis of TiB2 versus Tic in a variety of Ti/C/B mixtures under a variety of experimental conditions has also been the subject of a recent study.I2 Three publications from Lucci Antonione and co-workers have appeared dealing with local order in glassy Pd-B alloy^,'^ amorphous-to-crystalline transformations in Ni-B alloy^,'^ and the effects of additives on the corrosion resistance of amorphous Fe-B allows.Is The first compound containing a B=C double bond (1) has been synthesized and spectroscopically characterized.l6 Its stability is rationalized by the presence of the four bulky substituents. The thermally stable three-membered BC2 ring borirene (2) and the four-membered B2C2 ring diboretene (3) have also been rep~rted.'~ Both are two-.rr-electron aromatics.On the basis of previous theoretical work it is suggested that (3) has a non-planar C,,geometry. Me I Me,Si \ C-C=B-CMe CMe '\/Me,Si B I Bu' ,Bu' 'c=c Me \/B I Bu' -ck B -.>C-But ~ -y B I Me (1) (2) (3) 2 Halides The laser-induced reaction between c6F6 and BC13 affords" mainly BC12F and C6F5Cl. Halide exchange has also been studied in the B2F4/B2C14 B2C14/B2Br4 and B2C14/B13 systems the last affording B~14.l~ BF3 reacts with the adducts Me,N.AlH or Me,N.GaH in the gas phase to yield BF2H by halide-hydride exchange.20 No evidence was found to support a previous claim that Lewis acid displacement affording Me3N-BF3 and GaH, occurs in the gallium system. Instead it is proposed that the reactions proceed according to equations (1) and (2) with subsequent decomposition of MH2F.lo T. Ohtani B. Chevalier P. Lejay J. Etourneau M. Vlasse and P. Hagenrnuller J. Appl. Fhys. 1983 54 5928. I' T. Ishii M. Shirnada and M. Koizumi J. Magn. Magn. Muter. 1983 31 151. l2 V. A. Shcherbakov and A. N. Pityulin Fiz. Goreniya VZ~~UQ 1983 19 108. I3 G. Cocco S. Enzo L. Schiffini L. Battezzati and A. Lucci GQZZ. Chim. Ira[. 1983 113 269. 14 C. Antonione L. Battezzati E. Lazoni and A. Lucci GQZZ. Chim. Ztal. 1983 113 293. l5 J.-P. Crousier J. Crousier Y. Massiani and C. Antonione GQZZ. Chim. ZtaL 1983 113 329. l6 H. Klusik and A. Berndt Angew. Chem. Znt. Ed. Engl. 1983 22 877. " S. M. van der Kerk P. H. M. Budzelaar A. van der Kerk-van Hoof G. J. M. van der Kerk and P. von R.Schleyer Angew. Chem. Znt. Ed. Engl. 1983 22 48. P. Engst M. Horak and J. Pola Collect. Czech. Chem. Commun. 1983 48 1314. I9 W. Haubold and P. Jacob Z. Anorg. Allg. Chem. 1983 507,231. 20 A. E. Shirk and J. S. Shirk Inorg. Chem. 1983 22 72. Boron 21 BF + Me3N.MH3 + Me3N.MH3BF3 (1) Me3N.MH,BF3 -BF,H + MHzF + NMe3 (2) M = Ga or A1 Recent developments in n.m.r. pulse sequencing have facilitated completion of the measurement of "N and "B spectra of the series of NMe adducts of the mixed boron trihalides BXiX' (X' X2 = F C1 Br or I in all permutations) and of Me,N.BC1BrI.21 A number of correlations are established most importantly that between J("B-"N) and the strength of the N-B bond. This is therefore a more useful (and is anyway more easily measured) parameter than S("N) which does not correlate well with the adduct bond strength.In the past S("B) has been employed to estimate the strength of the donor-acceptor bond in trihalogenoborane adducts and Martin et al. have used this parameter to confirm that the acceptor strength of BBr in a variety of pyridine adducts is greater than that of BF,. 'H N.m.r. data are also reported.22 Similarly spectroscopic studies of the complexes (4) derived from 1,2,3,4-tetrahydro- 1,lO-phenanthroline show a progressive N(pyridine)-B co-ordination in the series X = F C1 Br I., A crystallographic of (4; X = F) shows that the B-N co-ordinate bond 1.629(7) A is substan- tially longer than the other B-N bond 1.500(6) A. SiFMe,I N SiFMe,I Me2SiHN\SiMe2 I I N.HN .,N\s1 F /N\B Me2 .AH s1 BF,-etherate reacts with 2,2,4,4,6,6-hexamethylcyclotrisilazanesand their lithium salts to yield silaborazines or the BF-bridged species (5),as reported two years ago. Crystallographic of (5) has shown that the molecule has space-group required CZvsymmetry along the B-F bond 1.348(5) A and cyclotrisilazane rings of conformation intermediate between boat and twist. Adducts of halogenoboranes and SMe are known hydroboration reagents towards alkenes and it has now been shown26 that since addition of traces of free Lewis acid dramatically catalyses the hydroboration (by trapping free SMe,) the overall mechanism involves prior dissoci- ation according to equations (3)-(5). This mechanism explains the previously BHBr,-SMe BHBr + SMe (3) BHBr + alkene -RBBr (4) RBBr + SMe S RBBr,.SMe2 (5) R = alkyl 2' J.M. Miller Znorg. Chem. 1983 22 2384. 22 D. R. Martin J. U. Mondal R. D. Williams J. B. Iwamoto N. C. Massey D. M. Nuss and P. L. Scott Inorg. Chim. Acta 1983 70 47. 23 G. Klebe K. Hensen and J. von Jouanne J. Organometal. Chem. 1983 258 137. 24 G. Klebe K. Hensen and H. Fuess Chem. Ber. 1983 116 3125. 25 W. Clegg Acta Crystallogr. Sect. C 1983 39 387. 26 H. C. Brown and J. Chandrasekharan Organometallics 1983 2 1261. 22 A. J. Welch apparent anomaly that BHBr,-SMe is a faster hydroboration reagent than BHCl,*SMe, since dissociation of the weaker adduct RBC1,.SMe2 into RBCl and SMe2 has a larger rate-retarding effect. The continuing importance of BF3 as catalyst for a wide variety of chemical reactions is demonstrated by the following small selection addition of NF30 to alkenes to afford N,N-difluoro-0-perhalogenoalkylhydroxylamines;27 efficient and regiospecific coumarin photodimerization;28 low-temperature stereospecific car-bonylation of (7-C,H,)Fe(CO)(phosphine)( Me) complexes ;29 and the formation of 1,2-dioxolanes from the reaction between alkenes and o~onides.~' 19 F N.m.r.spectroscopy is used to distinguish between the co-ordinated and terminal tetrafluoroborate F atoms in (7-C,H,)M(CO),(L)(FBF,) [M = Mo or W; L = CO PPh, or P(OMe),] and to follow bridge-terminal exchange at elevated temperature.,' Crystallographic and i.r. spectroscopic study of the first example of a BF anion bridging two metal centres has been given,, for +Cu(bipy)FB( F),F-3 [BF,].The co-ordination geometry at the Cu" centre is elongated rhombic trans octahedral with asymmetric Cu- F distances of 2.560( 5) and 2.656(5) A complemented by B to p-F bond lengths of 1.372(5) and 1.395(6) A respectively. Consistent with this the i.r. spectrum of the complex shows at low temperature three peaks centred on 1100 cm-' due to local C,,symmetry. A useful compilation of crystallographic and i.r. spectra data for co-ordinated BF is given in this paper. 3 Boron-Oxygen Sulphur and -Selenium Compounds The reactions of B(OH) with the aliphatic amines diethylamine 2-aminoethanol ethylenediamine and hexamethylenetetramine in aqueous media have been investi- gated,, and a cyclic borate of stoicheiometry Et,NH.12B,O3.3H20 isolated from the boric acid-Et2NH system.34 B(OH) is produced by acid degradation of [B3H7( NCS)]- in the atmosphere and structural study of [( Ph,P),N]Cl.B(OH) shows that the association of B(OH)3 molecules into infinite sheets is prohibited by hydrogen-bonding with chloride ions.35 Enthalpies of formation of 1 :1 and 1 :2 complexes of B(OBu) with SbC1 and TiC14 have been measured and not unreasonably are ca. twice for the Sb species what they are for the Ti complex.36 Raman spectra of alkaline solutions of lithium metaborate containing peroxide are consistent with an equilibrium between [B(OH)J and [B(OH),OOH]- anions,37 according to equation (6). B(OH) + H202 B(OH),(OOH)-+ H,O (6) 27 R.D.Wilson W. Maya D. Pilipovich and K. 0. Christe Inorg. Chem. 1983 22 1355. 28 F. D. Lewis D. K. Howard and J. D. Oxman J. Am. Chem. SOC. 1983 105 3344. 29 H. Brunner B. Hammer I. Bernal and M. Draux Organornetallics 1983 2 1595. 30 M. Yoshida M. Miura M. Nojima and S. Kusabayashi J. Am. Chem. SOC. 1983 105 6279. 31 K. Sunkel G. Urban and W. Beck J. Organometnl. Chem. 1983 252 187. 32 J. Foley D. Kennefick D. Phelan S. Tyagi and B. Hathaway 1. Chem. Soc. Dalton Trans. 1983,2333. 33 R. S. Tsekhanskii V. G. Skvortsov and A. K. Molodkin Zh. Neorg. Khim. 1983 28 859. 34 V. G. Skvortsov R.S.Tsekhanskii A. K. Molodkin V. M. Akimov 0.V.Petrova and V. P. Dolganev Zh. Neorg. Khim. 1983 28 1313. 35 S. J. Andrews D. A. Robb and A. J. Welch Acta Crystallogr.Sect. C 1983 39 880. 36 V. G. Tsvetkov V. P.Maslennikov N. G. Chernaya E. E. Grinberg and Yu. A. Aleksandrov Zh. Prikl. Khim. 1983 56 1922. 37 C. J. Adams and I. E. Clark Polyhedron 1983 2 673. Boron 23 The accurate electron density distribution in LiBO, which contains infinite chains of B03 triangles between which lie the lithium atoms has been determined. Interpre- tation of the deformation-density leads to a simplified bonding model of the LiB0 sub-unit which polymerizes into the observed structure.38 Isolated rather asym- metric B03 units are found in Pb40[Pb2(B03)3C1] for which a crystal structure and i.r. spectrum are reported.39 Bz03 reacts4’ with excess SO3 in sealed tubes to yield ‘B2O3.SO3’ at 90-95 “C and ‘B2O3.2SO3’ at 200 “C; i.r.and “B n.m.r. spectroscopic study4’ of these products does not yield unambiguous structures but does indicate that both species contain B03 and B04 units. H2L[B405(OH),] (L = ethylenediamine) results from reaction between aqueous B203 and excess ligand or by thermolysis of B(OH)3 with L.42 The hydrated magnesium borate ‘Mg0.3B2O3-7.5H,O’ has been isolated43 from borate-containing magnesium chloride brine and the B205 unit in both crystal modifications of anhydrous magnesium pyroborate ‘2Mg0-B2O3’ has been the subject of a thorough vibrational analysisa which has identified a marked difference in force constants between terminal and bridging B-0 bonds. In Tl[B304(OH)2].0.5H20 there are [B3O4(OH),]- units linked into an infinite chain [B30,(OH),]~m.Dehydration occurs in two steps affording first (453 K) Tl[B304(OH),] and then (493 K) TlB305?5 The thermolysis of borax Na,[B405(OH),].8H20 continues to be a subject of research interest. The product after complete dehydration Na20-2B203 is reported46 to decompose at 700 “C to yield NaBO vapour and B203. The system KF-B(OH)3-H20 has previously been shown to produce ‘KFsB(OH)~’ alternatively described as a salt K[BF(OH),] or as a triple F.-H bonded array. It has been demonstrated that an excess of B(OH) in the system affords the previously known borate K[B506(OH)4].2H20 and the possible role of F-as catalyst (rendering by OH- -.F bond formation the oxygen more nucleophilic and therefore more likely to attack a second boron centre) in its formation is discussed.High-field (127 and 160 MHz) I’B n.m.r. of aqueous polyborate equilibria have allowed calculation of formation constants for [B(OH),]- [B303(OH),]- and [B506(OH),]- [see equations (7)-( 1O)] ;in parallel temperature- and concentration- dependent dissociation of the polyborate species has been studied. Limitations of 38 A. Kirfel G. Will and R. F. Stewart Acta Crystallogr. Sect. B 1983 39 175. 39 H. Behm Acta Crystallogr. Sect. C,1983 39 1317. 40 S. N. Kondrat’ev S. I. Mel’nikova and A. M. Bondar Zh. Neorg. Khim. 1983 28 851. 41 A. M. Bondar S. N. Kondrat’ev and S. I. Mel’nikova Zh. Neorg. Khim. 1983 28 855. 42 G. Ozolins R. V.Zinchenko and E. Silina Latv. PSR Zinat. Akad. Vestis. Kim. Ser. 1983 294. 43 S. Gao J.Zhao F. Xue and T. Hu Huaxue Xuebao 1983,41 217. 44 Yu. N. Win V. V. Kravchenko and K. I. Petrov Zh. Neorg. Khim. 1983 28 1609. 45 M. Touboul C. Bois D. Mangin and D. Amoussou Acta Crystallogr. Sect. C 1983 39 685. 46 E. Hartung K. Heide R. Naumann K. H. Jost and W. Hilmer J. Ilherm. Anal. 1983 26 277. 47 J. Emsley and J. S. Lucas J. Chem. Soc. Dalton Trans. 1983 181 1. 48 C. G. Salentine Inorg. Chem. 1983 22 3920. A. J. Welch the method however are that no signals were detected for the [B4O5(0H)J2- ion which must be present equation (9) and that only one boron environment is suggested for [B506(OH)4]-. In Na6CO3[B,07(0H),],.26H,O there are two different types Of [B&(OH)6] co-ordination to the transition Co( 1) is centrosymmetrically bonded to two water molecules and uia two Co-O(H) bonds to two polyborates whereas Co(2) (which occurs twice as frequently in the crystal lattice) is sandwiched between two polyborates each involved in three Co-O(H) bonds.Both modes of [B607(OH)6] co-ordination have been observed previously but their coexistence in one species serves to highlight the stereochemical diversity available in this area of boron chemistry. Two completely novel relatively large polyborate anions have been reported. In the first [B8OI2( OH),],- structurally studied as Tl,[borate].H,O there are four B04 tetrahedra and four B03 triangle^,^' and the structural formula is best represented as [B7010(OH)3.0BO(OH)]4- these units being linked together into an infinite chain.In contrast discrete anions exist of {CU~[B~~~~~(OH) (6) structurally studied5' as N~,(CU~[B~,~~,(OH)~~]}. 12H20. In (6) there are eight Bo3 triangles and eight B04 tetrahedra surrounding two planar Cu centres to afford the largest discrete polyborate anion yet reported. (6) (Reproduced by permission from Acfa Crystallogr. Sect. C,1983 39 20) Potassium bis-(4-methylcatecholato)borate surprisingly precipitates from a slightly basic very dilute aqueous solution of B(OH)3 and ligand and this result has prompted a general discussion of equilibria in the boric acid-catechol system.52 Alkylboronic esters R' B( OR2)2 transfer the alkyl group R' from boron to carbon by reaction53 with methoxy(pheny1thio)methyl-lithium subsequent oxidation of the product R1CH(OMe)B(OR2)2 affording the aldehyde R'CHO.This homologation of boronic esters as a synthetic method in chiral organic syntheses is an important area and one of much current activity due largely to the efforts of Matteson and 49 H. Behm Actu Crystullogr. Sect. C,1983 39 1156. M. Touboul C. Bois and D. Amoussou J. Solid Sfate Chem. 1983 48,412. 51 H. Behrn Acta Crystallogr. Sect. C 1983 39 20. 52 L. Babcock and R. Pizer Inorg. Chem. 1983 22 174. 53 H. C. Brown and T. Imai J. Am. Chem. Soc. 1983 105 6285. Boron 25 co-workers. It is however outwith the intended scope of the present Report and we therefore refer interested readers to references 54-60. The stable bridged borate ester B(OCH2C3H4CH20)B (7) has been synthesized and structurally characterized.6' The molecule has overall C3 symmetry and the cyclopropane bridges give the molecule helicity thus affording a conformationally stable symmetric species which has accordingly been studied by FT i.r.Raman and vibrational circular dichroism spectroscopy. (7) (Reproduced by permission from Inorg. Chem. 1983 22 23 19) Important recent developments in boron sulphide boron selenide and thioborate chemistry have been lucidly reviewed by Krebs.62 One of the compounds featured in this review is the macrocycle B8S16 first synthesized in 1980. Its electronic structure was analysed at the Huckel level in 1982 and now the same workers have re-evaluated the molecule with particular reference to possible complex formation by extended Huckel (EH) MO calculation^.^^ If the basis set includes sulphur 3d AOs with a coulomb integral value of -8 eV a Cu2+ centre is bound by the macrocycle about as strongly as it is by porphine but if the integral is set at only -4 eV the calculated Cu-S bond strength drops by about two-thirds.The synthesis and 13C n.m.r. spectra of five dialkylamino(ethy1thio)phenylboranes have been reported.64 Rotation about the B-N bond is considered more restricted 54 D. S. Matteson and K. M. Sadhu J. Am. Chem. SOC. 1983 105 2077. 55 D. S. Matteson and D. Majumdar Organornetallics 1983 2 230. 56 D. J. S. Tsai and D. S. Matteson Organometallics 1983 2 236. 57 D. S. Matteson and D. Majumdar Organometallics 1983 2 1529. 58 D. S. Matteson and E. Erdik Organometallics 1983 2 1083.59 D. S. Matteson R. Ray R. D. Rocks,and D. J. Tsai Organometallics 1983 2 1536. 60 D. J. S. Tsai P. K. Jesthi and D. S. Matteson Organometallics 1983 2 1543. 61 V. J. Heintz W. A. Freeman and T. A. Keiderling Inorg. Chem. 1983 22 2319. 62 B. Krebs Angew. Chem. Znt. Ed. Engl. 1983 22 113. 63 B. M. Gimarc and J.-K. Zhu Znorg. Chem. 1983 22 479. 64 R. H. Cragg and T. J. Miller J. Organometal. Chem. 1983 243 387. A. J. Welch in these species than in analogous alkoxy-compounds since the B-S .n-bond is less strong than that between B and 0. Two routes to arylboronic acids have been described. One-pot synthesis is afforded by the reaction between arylmagnesium halides and borane compounds followed by hydr~lysis,~~ and ortho-lithiation of substituted benzylamines and reaction with trimethylborate allows synthesis of arylboronic acids with intramolecular N -B bonding.66 Such bonding occurs in (8) (R = H or Me) but not when R = Ph as evidenced by ‘H and IlB n.m.r.data.67 A temperature-dependent fluctionality in the adduct bonding between a variety of amines and either triethyl- or triphenyl-boroxine is shown by n.m.r. studies and this has been interpreted in terms of the low- temperature limiting spectrum being that in which only one boron is bound to nitrogen (9). This supposition is entirely consistent with the results of a crystallo- graphic determination68 of 2(PhBO),-3(p-H,NC6H,NH2) which has a B :N ratio of I 1 but is such that one phenylenediamine molecule bridges two boroxines leaving two free amines of solvation (10).(8) (9) R = Et or Ph CY (10) (Reproduced permission form Gem.Ber. 1983 116 3347) 65 G. W. Kabalka U. Sastry K. A. R. Sastry F. F. Knapp jun. and P. C. Srivastava J. Organometal. Chem. 1983 259 269. 66 M. Lauer and G. Wulfe J. Organometal. Chem. 1983 256 I. 67 R. Contreras C. Garcia T. Mancilla and B. Wrackmeyer J. Organometal. Chem. 1983 246 213. 68 M. Yalpani and R. Boese Chem. Ber. 1983. 116 3347. Boron 27 4 Boron-Nitrogen -Phosphorus and -Arsenic Compounds An improved synthesis of a crystalline poly( aminoborane) ( H,NBH2) has been described and on the basis of its X-ray powder pattern and very low solubility it is supposed that the species is either a cyclic or linear polymer of relatively high molecular Two forms of methyleniminoborane H2C=N-BH2 have been investigated by geometry-optimized ab initio MO cal~ulations.~~ The linear orthogonal form (1 1) is more stable than the planar bent form (12) by 46.9 kJ mol-' which contrasts with (1 1) (12) results of the (previously studied) isoelectronic H2B-0-BH2.In (1 1) bond lengths and electron population analyses support strong N-B .rr-bonding. In B( N=CBU~~)~ (13) the stereochemistry is such that the NCBut units are all perpendicular to the central plane thereby allowing for overall maximal N -D B v-b~nding.~' Thus the orthogonality of B and C co-ordination planes in (13) parallels that in (1 1). The N-B distance in (13) is 1.39(2) A and C-N is 1.23 A.An alternative bonding mode for imines is that of a bridging 3-e ligand as found in the centrosymmetric dimer (14) reported in the same communication. Me Me Me Me (14) R = Me or Ph Molecular Orbital Bond Index '(MOBI) calculations have been used72 to probe preferred geometries of N( BH2)3 and B,( NH,),. Unfortunately there are serious typesetting errors and/or inconsistencies in the paper that result in this reviewer being unable fully to correlate figures tables and text. What is clear (I think) is that N( BH2)3 is most stable with one BH2 unit coplanar with the central NB3 moiety and the other two perpendicular to it and that B6( NH2) is most stable with a planar B6 ring which contrasts with the established chair conformation in the crystal structure of B6( NMe2),.Charge distribution in BH2R H3N*BH2R RH2N and RH,N-BH has been calculated73 by four methods (CNDO MNDO Jolly and 69 R. Komm R. A. Geanangel and R. Liepins Inorg. Chem. 1983 22 1684 2222. 70 G. Gundersen and S. Saebo Acta Chem. Scand. Sect. A 1983,37 277. 7' J. R. Jennings R. Snaith M. M. Mahmoud S. C. Wallwork S. J. Bryan J. Halfpenny E. A. Petch and K.Wade J. Organometal. Chem. 1983 249 CI. 72 A. Neckel H. Polesak and P. G. Perkins Inorg. Chim. Acta 1983 70 255. 73 W. Linert V. Gutmann and P. G. Perkins Inorg. Chim. Acta 1983 69 61. A. J. Welch Perry and modified Sanderson) and for the adducts only the last is found to be reasonably concordant with experience. In the adduct of BBr3 with pyridine the N-B co-ordinate bond is 1.59(2) A.74 Polarographic reduction of substituted trimethylamine- N-pyridylboronium cations has been f~llowed,~' and N-co-ordination of inter ah the BEt function to 4,4'-bipyridyl affording the radical cation (19 has been studied with a view to possible control of the redox properties of the liga~~d.~~ Full details have now been reported7' of variable-temperature I3C n.m.r.spectro- scopic studies of the series of aminoboranes PhB(X)-NR2 (X = F C1 Br OMe or SEt; R = Me or Pri) used to delineate steric and electronic effects upon the barrier to rotation about the B-N bond. The series chosen for study is particularly interesting in that conflicting sequences exist within with regard to the ease of rotation.A further paper from the same group7* reports aminoboration of phenyl isocyanate by 27 aminoboranes where X is additionally extended to NH2 and NHR. Clearly there are two potential products PhB(X)N(Ph)C(0)NR2 or PhB( NR,)N(Ph)C(O)X depending upon the relative migratory aptitude (RMA) of NR2versus X. It is found that RMAs decrease in the series BuNH > N(CH2)3CH2> N(CH2)4CH2> Me2N > Et,N > Bu'NH > N(CH,),CHMe > Pri2N and RS > RNH > R2N > OR halide or Ph. Thermolysis of diarylaziodoboranes Ar,BN3 affords either diazadiboretidines (16; R' = R2 = Ar) or borazines (ArBNAr)3 via boryltetra-azaborolines (17) and with BEt isomeric diboronylamines (IS) and (19) are produced. The possible inter- mediacy of boron imides ArB=NAr in these reactions has been discussed.79 The imide Bu"B=NBu' (20) dimerizes to (16; R' = But R2 = Bun) in the presence of a catalytic amount of t-butyl isocyanide and the product may be stabilized by q4-co-ordination to either a Cr(CO) or W(CO)4 unit.80 A crystal structure determi- nation of the Cr complex reveals that the N atoms are trans to CO with the boron atoms bent away from the metal [Cr-B 2.354(4) 2.361(4)A Cr-N 2.205(2) 74 K.Iijima I. Oonishi and S. Shibata Chem. Leff. 1983 251. 75 K. Zutshi G. E. Ryschkewitsch and P. Zuman Inorg. Chem. 1983 22 564. 76 W. Kaim J. Organometal Chem. 1983 241 157. 77 C. Brown R. H. Cragg T. J. Miller and D. O'N. Smith J. Organometal. Chern. 1983 244 209. 78 R. H. Cragg and T. J. Miller J. Organomefal.Chem. 1983 255 143. 79 P. Paetzold and R. Truppat Chem. Ber. 1983 116 1531. 80 K. Delpy D. Schmitz and P. Paetzold Chem. Ber. 1983 116 2994. Boron 29 Ar\ Et ,B-N\ BEt2 /Ar Ar Et \/B-N/\Ar BEt2 Bu'Bun\ /B-N I 1 N-P \ (18) (19) R2/ NR (21) a; R' = R2 = SiMe b; R' = Pri R2 = But 2.210(2) A] leading to a BNBN ring which is folded by 21.9" about N...N . With iminophosphanes (20) affords (21) by cycloaddition.81 Electrophilically induced substitution reactions at boron of pyrazaboles (22) have been studied and an extensive range of derivatives has been synthesized. Molecular structures determined for (22) with R' = R2 = R3= R4 = Cl Y = H; R' = R2 = R3 = R4 = SMe Y = H; R'R2 = R3R4 = SCH2CH2S Y = H; R' = R3 = Ph R2 = R4 = N2(CH),CH,Y = H;andR' = R4 = Br,R2 = R3 = H,Y = Clsuggest that the potential for deformation of the central B2N4 ring is rather soft since a number of different conformations are observed.82 The synthesis and reactions of I ,3-dimethyl-2-(pyrazol-1'-y1)-1,3-diazaboracyclopentanes have been studied in recent years.In 1983 the equivalent cyclohexane derivatives (23) have been prepared and it is found that the Lewis acidity of the boron atom of (23) is considerably less than that of the former species presumably as a consequence of the wider annular NBN angle.83 Complete assignment of the 13C n.m.r. spectra of the substituted borazine [MeBN( o-tolyl)] and the related heterocycle (24) have been reported and the chemical shifts of the latter correlated with charge densities from HMO calcula-tion~.~~ The molecular structures of the 19e complexes (25)8s and (26)86 have been determined.In (25) there are two crystallographically independent molecules each with Cisymmetry whereas (26) exists in two conformations corresponding to clockwise and anticlockwise arrangements of the azaborolinyl rings. In all four species the formal electronic excess at Co is somewhat relieved by slipping of the " P. Paetzold C. von Plotho E. Niecke and R. Ruger Chem. Ber. 1983 116 1678. a2 K. Niedenzu and H. Noth Chem. Ber. 1983 116 1132. F. Alam and K. Niedenzu J. Organometal. Chem. 1983 243 19. 84 S. Allaoud H. Bitar M. El Mouhtadi and B. Frange J. Organometal. Chem. 1983 248 123. 85 G. Schmid U. Hohner D. Kampmann D. Zaika and R.Boese J. Organometal. Chem. 1983,256,225. 86 G. Schmid and R. Boese Z. Naturforsch. B Anorg. Chem. Org. Chem. 1983 38 485. A. J. Welch I -Me ligands such that B and N atoms are further from the metal than are C atoms. (25) and (26) are readily oxidized to 18e monocations by either I or [(q-C,H,),Fe]+. Paramagnetic Mn" and Co" bis-ligand complexes of the (dimethylmethyl-enephosphorany1)dihydroborate anion (27) have been synthesized. The ligand is an excellent a-donor and minimal wacceptor. Magnetic data are reported in solution for both and in the solid for the cobalt complex and a single -crystal X-ray diffraction study of the manganese species (the Co analogue is isomorphous) confirms tetrahe- dral geometry and shows that both six-membered rings have chair conformation^.'^ (27) (28) Cyclenphosphorane reacts" with B,H to yield the bis-adduct (28) a surprisingly stable species and the first established example of a molecule with the sequence H,B-N-P-N-BH,.BH adducts of transition-metal substituted arsanes (q-C5H5)M(L)(C02)As(Me),BH,(29) (M = W or Mo L = CO or PMe,) have been prepared by reaction between the metal complex and H,B.THF. Treatment of (T-C~H,)MO(CO),AS(M~),BH, with PMe affords both (29; M = Mo L = PMe,) by CO substitution and (T-C~H,)MO(CO)~ASM~~Me,P.BH3 by BH, plus ab~traction.'~ 5 Heterocyclic Derivatives The ability of BX (X = typically halide alkyl or aryl) groups to bridge the oxygen atoms of transition-metal bis-( a-dioFimato) c?mplexes and form stable macrocyclic species with heterocyclic functions MNOBON is well established and continues to be of irnportan~e.~~ It has recently been shown that additionally such groups can act as linking functions between two such metal comple~es.~' Chelation of the BX2 group by N-alkyl- or N-aryl-hydroxamic acids affords the heterocyclic compounds (30) synthesized9 for various X R' and R2,and discussed in terms of the resonance structures shown.An analysis of bond lengths in two crystallographically studied9 examples (31 ; R3= R" = H) and (31 ; R3= Me 87 G. Muller D. Neugebauer W. Geike F. H. Kohler J. Pebler and H. Schmidbaur. Organometallics 1983 2 257. 88 J.-M. Dupart S. Pace and J. G. Riess J. Am. Chem. Soc. 1983 105 1051. 89 R. Janta R. Maisch W.Malisch and E. Schmid Chem. Ber. 1983 116 3951. 90 F. S. Stephens and R. S. Vagg Inorg. Chem. Acra 1983 69 103. 9' M. L. Bowers and C. L.Hill Inorg. Chim. Acta 1983 72 149. 92 W. Kliegel and D. Nanninga Chem Ber. 1983 116 2616. 93 W. Kliegel D. Nanninga S. J. Rettig and J. Trotter Can. J. Chem. 1983 61 2493. Boron 31 /\ /\ Ph Ph Ph Ph a b (31) R4 =C6Hll),suggests that although both forms are important the B,N-betaine structure (b) is dominant. A following paper94 by the same group describes the synthesis and structure of bis[salicyladoximato(2-)phenylboron] shown to contain the first crystallographically studied B2N202ring (as one of five fused six-membered rings). Molecular parameters are discussed in terms of contributions from four resonance structures (32a-d).Ph Ph Ph Ph a b In attempting to synthesize the B2N202ring-containing dimer of (isopropy- 1ideniminoxy)diphenylborane from acetone oxime and oxybis(dipheny1borane) many years ago it was found that an adduct was produced containing phenylboronic acid and diphenylboronic acid moieties. However extensive chemical and spectro- scopic study could not distinguish between structures (33a) and (33b) for this adduct. Now crystallographic analysis has unambiguously established (33a) as correct.95 Me Me Ph \ +AB/Ph \ +,o,-/ C=N B-Ph /“=Y 1 \I Me ,B-0 Me / Ph I /B-o Ph Ph a b (33) 94 S. J. Rettig and J. Trotter Can. J. Chem. 1983 61 206. 95 W. Kliegel D. Nanninga S. J. Rettig and J. Trotter Can.J. Chem. 1983 61 2329. A. J. Welch Molecular structures have also been determined96 of the five- and six-membered heterocycles (34) (34)-B(Ph),PH solvate and (35) and a correlation is established between the lengths and the rates of hydrolytic cleavage of the N-B bonds in (34) (35) and (36). (36) R = H F or Me Seven-membered BOCCCNO heterocycles with the B,N-betaine structure (37) have been ~ynthesized~~ from nitrones of salicylaldehyde by entirely analogous routes to those leading to (30) and six-membered analogues (38) are affordedg8 by reaction of 2-formylphenylboronic acid with N-substituted hydroxylamines followed by esterification. With phenylboronic acid and formaldehyde RN( H)OH yields the bicyclic species (39) characterized spectroscopically99 for R = Me Et Pr" Pr' C6H11 and CH2Ph.H \ -/ f-J.+R\ B'Od=;\fO'B XIX 0 (37) (38) R PhB 1 P-NqNRI 04:-0' Ph (39) Octahydroxycyclobutane reacts with trialkylboranes dichloro-organoboranes and trialkylboroxines to yield'" the pentaheterocyclic product (40). In the presence of Et2BC(0)OBu' the thermochromic species (41 ;R = Et) is also formed by cleavage of the cyclobutane ring and following up this observation Yalpani and Koster have additionally synthesized a range of products (41) from dihydroxybutenedioic acid and boron substrates."' When R is an n-alkyl or iso-alkyl group (41) is thermochromic being colourless when 'hot' and yellow when 'cold'. For R = t-alkyl or aryl however (41) is colourless even to 4 K. Crystal structureslo2 of (41;R = Et) at 40 "C and -30 "C and for comparision of (41; R = Ph) at room temperature RR (40) (41) 96 S.J. Rettig and J. Trotter Can. J. Chem. 1983 61 2334. 97 W. Kliegel and D. Nanninga J. Organometal. Chem 1983 243 373. 98 W. Kliegel and D. Nanninga J. Organometal. Chem. 1983 247 247. 99 W. Kliegel J. Organometal. Chem. 1983 253 9. 100 M. Yalpnai R. Koster and G. Wilke Chem. Ber. 1983 116 1336. 101 M. Yalpani and R. Koster Chem Ber. 1983 116 3332. I02 M. Yalpani R. Boese and D. Blaser Chem. Ber. 1983 116 3338. Boron 33 have shown that the yellow colour of the 'cold' form results from intermolecular bonding between the boron atoms of one molecule with carbonyl oxygens of adjacent ones in concert with a bend-back of pendant ethyl groups.1,2-Dihydro- N-substituted- 1 -aza-2-borabenzenes are compounds of pharmaco-logical interest and the synthesis of N-phenyl analogues from PhBC1 and the corresponding a,P-unsaturated o-aryl azide has recently been reported. lo3 The adduct Me3N-BH,CH2SMe decomposes upon heating to yieldlo4 the dithiodiboracyclohexane derivative (42) whose n.m.r. spectra show the presence of two isomers corresponding to both methyl groups axial or equatorial; in the solid state the latter is found. H7 x-Ph The reactions of 1-X-4-boracyclohexa-2,5-dienes (43) obtained from the radical- initiated reaction between Et,NB(C_CR) and H,XPh have been ~tudied.'~' Partial hydrogenation of the arsenic compound is possible with additional H2AsPh.The B-bonded exocyclic function may be substituted stepwise by OMe and But and X may be alkylated after cleavage of the X -Ph bond by alkali metals. Phosphorus(v) derivatives with additional P=E (E = 0 S or Se) bonds may also be obtained. In the final part of this section we concentrate on a number of transition-metal complexes with m-bonded B,C heterocyclic ligands. Occasionally their strict classification as heterocyclic derivatives is tenuous since especially when the B :C ratio is relatively high a case could be argued for regarding them as polyhedral carba(metal1a)boranes. This is of course perfectly reasonable and it is right that there should be no rigid boundaries between areas. Palladino and Fehlner have synthesized'06 (7-CsHs)Co( q-C4Ph4BH) in,ca.20% yield by reaction of the metallacyclobutadiene (r]-CSH5)(PPh3)Co(CPh),CPh with BH,.THF and suggest that this synthetic approach to carbon-rich carbametal- laboranes has potential. An interesting complement to this work is f~rnished"~ by the generation of nido-[l-I-2 3 4 5 &Me5-& 3 4 5 6,-CsB]+ (writing it as a cluster) from [(r]-CSMe5)Sn]+ (writing it as a metal-ligand complex) by reaction with B13. Ethene displacement from (T-C,H~)CO(C~H~)~ by 1,3-diborolenes affordslog com- plexes (44). In (44) the axial H atom of the endocyclic methjrlene carbon C-2 is acidic and facile deprotonation affords monoanions which are readily alkylated. A molecular structure of (44a) shows that C-2 is formally five-co-ordinate and semi- empirical MO calculations reveal a frontier orbital which is three-centre C0-C 2-H from whose form it is clear that strong Co-C-2 bonding is directly responsible for weak C-2-H bonding (and thus acidic H).Therefore the formal diborolene 103 R. Leardini and P. Zanirato J. Chem. SOC. Chem. Commun. 1983 396. 104 H. Noth and D. Sedlak Chem. Ber. 1983 116 1479. 105 H.-0. Berger and H. Noth J. Organometal. Chem. 1983 250 33. I06 D. P. Palladino and T. P. Fehlner Organometullics 1983 2 1692. 107 F. Kohl and P. Jutzi Angew. Chem. Int. Ed Engl. 1983 22 56. log J. Edwin M. C. Bohm N. Chester D. M. Hoffman R. Hoffmann H. Pritzkow W. Siebert K. Stumpf and H. Wadepohl Organometullics 1983 2 1666. A. J. Welch ligand of (44) is appreciably perturbed towards the more common diborolenyl form of which many examples are known.The anionic (44b)- with SnC12 afford^'^' the bent quadruple-decker complex [( q-C5H5)Co( q-C2Et2B2Me2CH)],Sn in which the Co-Sn vectors interesect at 130"; the bent geometry of this complex is broadly similar to that of (q-C,H,),Sn. Et (44) a; R' = Et R2= Me b; R' = Me R2 = H Syntheses reactivities electrochemistries and solid-state structures of and bond- ing within triple-decker 1,3-diborolenyl complexes with 29-34 valence electrons have been the subject of a very extensive study by Siebert Geiger Kruger Bohm and co-workers.'" The complexes studied are (q-C,H,)M'[p-( q-C,B2H,)]M2( q-C5H5) with M'M2 = FeCo+ (29 valence electrons) FeCo (30) CoCo (31) CoNi (32) NiNi (33) and NiNi- (34).Triple-decker complexes (OC)3Mn(p-L)Mn(C0)3 and (7-C,H,)Fe(p-L)Fe( q-C5H5) (L = 2-ethyl-l-phenylborole), each of which has 30 valence electrons have been prepared and structurally and spectroscopically characterized.' '' Formed with the latter is the borabenzene derivative (q-C5H,)Fe(2-MeC,H,BPh) ;the synthesis and substitution reactions of the interesting boraben- zene/butadiene cobalt complexes (45) form the basis of a separate Finally the preparation and spectroscopic characterization of the metal complexes M(CO) (M = Cr Mo or W x = 4; M = Fe Ru Os x = 3) of the q6-1,4-diferrocenyl-l,4-diboracyclohexa-2,5-dieneligand have been described.'I3 R' >-( R' co R' (45) R' R2 = Me or Ph 6 Boranes and Derivatives The mechanism of the reaction of ethene with the adduct H3B.0H2 has been studied by ab initio MO calculations as a model for hydroboration in ether solvents."4 As I09 H.Wadepohl H. Pritzkow and W. Siebert Organometallics 1983 2 1899. 'Io J. Edwin M. Bochmann M. C. Bohm D. C. Brennan W. E. Geiger C. Kruger J. Pebler H. Pritzkow W. Siebert W. Swiridoff H. Wadepohl J. Weiss and U. Zenneck J. Am. Chem. SOC.,1983 105 2582. Ill G. E. Herberich J. Hengesbach G. Huttner A. Frank and U. Schubert J. Organometal. Chem. 1983 246 141. 1 I2 G. E. Herberich and A. K. Naithani J. Organometal. Chem. 1983 241 1. I13 G. E. Herberich and M. M. Kucharska-Jansen J. Organometal. Chem. 1983 243 45. I14 T. Clark D. Wilhelm and P. von R. Schleyer J. Chem. SOC.,Chem.Commun. 1983 606. Boron 35 shown in Scheme 1 the transition state involves an SN2-like displacement of the solvent by the alkene so that all four valence orbitals of the boron atom are always utilized. 9 "H 9 .Ji H \ ,--\ ,B,H H--C(1)-C(2>-H H/ \ t H H-. .-H )C( 1)=c(2); H H Scheme 1 Radiolysis of NaBH at 77 K affords the -BH4 radical e.s.r. parameters for which are reported and interpreted in terms of a C,,distorted geometry (in agreement with the conclusions of a parallel MNDO ~tudy)."~ The .BH4 radical is proposed to be an intermediate in the U.V. photolysis of the hydroborate anions BH4- [BH3(CN)]- and [BH(OBu'),]- in liquid ammonia rapid proton loss then affording the appropriate radical anion.'I6 Borane radical anions have previously been gener- ated from hydroborates by H atom abstraction+using alkoxy-radicals,' I7 and the same technique affords amine-boryl radicals J3N- BH from amine-borane com-plexes."' Analysis of the e.s.r.spectra of Et3N-f3H2 and Et,P-bH suggests that the geometry at B is pyramidal in the former and planar in the latter. Both the borane radical anion and its amine and phosphine complexes react with alkyl halides to give alkyl radicals."77118 Diffusion coefficients of BH4- at temperatures from 286 K to 313 K in aqueous solution at pH 12 have been reported and the diffusion control of the limiting current (dropping mercury electrode) has been established.' l9 Gyori and Emri have reported the synthesis of novel cyano- and isocyano-derivatives of BH3 and of BH4- generally in good yields.'20,'21 Specifically the dicyano anion [BH2(CN),]- is described for the first time. Super-tritide the tritiated analogue of the well known super-hydride LiEt,BH has been prepared and shown to have much the same powerful and stereospecific reducing properties as its hydride parent;'22 it thus appears to be a superior tritium labelling reagent to either NaBT or LiAlT,. Coulometric titration of adducts of diborane with oxidants such as bromine iodine or hypoiodite has been suggested as a suitable method for the determination of dib~rane.',~ 'Is M. C. R. Symons T. Chen and C. Glidewell J. Chem. Sac. Chem. Commun. 1983 326. 'I6 J. A. Baban J. C. Brand and B. P. Roberts 1. Chem. SOC.,Chem.Commun. 1983 315. I17 J. R. M. Giles and B. P. Roberts J. Chem. SOC.,Perkin Trans. 2 1983 743. I I8 J. A. Baban and B. P. Roberts J. Chem. Sac. Chem. Commun. 1983 1224. I I9 C. Biondi and L. Bellugi Gazz. Chim. Ital. 1983 113 525. I20 B. Gyori J. Emri and 1. Feher J. Organomeral. Chem. 1983 225 17. 121 J. Emri and B. Gyori J. Chern. SOC.,Chem. Commun. 1983 1303. I22 S. Hegde R. M. Coates and C. J. Pearce J. Chem. Soc. Chem. Commun. 1983 1484. I23 0. D. Kuleshova and A. I. Gorbunov Zh. Neorg. Khim.. 1983 28 83. A. J. Welch In 1982 an X-ray diffraction study showed that the [B2H7]- ion [as its (Ph3P)2N+ salt dichloromethane solvate] had a bent B -H -B bridge and overall C symmetry (46). Recent MO calculations to a very high level of sophistication (complete geometry optimization with a 6-3 1G**basis set and corrections for electron correla- tion using fourth-order perturbation theory) have confirmed the preference for a bent bridge system (although the potential surface to bending is rather flat) and shown that a bent ion with overall C2 symmetry (47) is equally ~tab1e.I~~ The triangular radical anion [B3H7]-' has been generated from [B,H,]- (H atom abstrac- tions using ButO*; see above) and e.s.r.data have been re~0rted.l~~ Tandem semi-empirical MO calculations suggest a structure of CZvsymmetry with a single B-H-B bridge (48). HH fR*,' The variety and complexity of the shapes of and possible substitution patterns in three-dimensional (polyhedral) boranes have led Casey Evans and Powell to seek a method of unambiguously describing and naming such species their analogues and their derivatives.Following earlier papers (1981) in which a descrip- tor system for closed polyhedra was established these authors have now expanded that system to encompass capped polyhedral 26 and have suggested nomenclature rules for closed'26 and non-~losed'~~ clusters. The rules outlined do not necessariy afford unique names but once derived they are unambiguous and structurally informative. As an example two descriptions of BgHl2 (49a) follow (i) (2,3-pH),(2,6-pH),(3,7-pH),(4,5,-pH)-1 v64v422) 1-deb~r[C~~-( -A'4-closo]nonaborane (ii) 1-debor[C2"-(1v64v222)-A14-~l~~~]nonaborane( 12)-2,3:2,6:3,7:4,5-pH4 An interesting alternative method of notation in clusters has been outlined by Hendon and Leonard in which a totally numerical description ('linear notation') of the polyhedral structure is achieved.'28 Unfortunately the linear notation and its shorthand version (which could serve as a unique registry number for use in data base searches etc.) are derived from a canonical numbering scheme that differs from that of Powell et al.Thus for numbered as in (49b) the linear notation is (0501)0203050604(0501)04070803(0501)08095 (0501)06 1007( 0501 )091 106( 0501) 1 110( 0501 )1208(0501) 12 (01)(01)(01)(O 1) I24 K. Raghavachari P. von R. Schleyer and G. W. Spitznagel J. Am. Chem. SOC.,1983 105 5917 12' J. M. R. Giles V. P. J. Marti and B. P. Roberts J. Chem. SOC.,Chem.Commun. 1983 696. 126 J. B. Casey W. J. Evans and W. H. Powell Inorg. Chem. 1983 22 2228. 127 J. B. Casey W. J. Evans and W. H. Powell Inorg. Chem. 1983 22 2236. I28 W. C. Herndon and J. E. Leonard Inorg. Chem. 1983 22 554. Boron 37 and the registry number is 52356454783589556107591165111051208512 Terminal H atoms not shown In 1982 Fuller and Keppert outlined a new method for analysing the structures and rearrangement pathways of three closo-boranes [B,H,]'- (n = 8 9 or 12). In this method every boron atom interacts with every other the strength of that interaction being (l/d") -(l/dY) and the total cluster bonding energy of the molecule being the sum of all such components. The coefficients x and y were set to 2 and 1 respectively by best fitting of the known structures of [B8H8I2- and [B9H9I2-.In a recent second paper'29 the same coefficients are used to predict optimized structures for all species [B,H,I2- for n =*5-12. In all cases where structures are known experimentally there is agreement with those predicted by this method and there is generally good agreement with the predictions of previous geometry-optimizing calculations (MNDO PRDDO). However a note advocating that the Fuller-Keppert approach be used with caution has also a~peared.'~' The criticisms are made that the method gives unrealistic relative energies within the series that it overestimates the lengths of B-B connectivities in small polyhedra and underestimates those in large ones that it overemphasizes the importance of radial versus tangential B-B bonding and that it leads to the unrealistic conclusion that relatively high-connected boron atoms are relatively more strongly bound within the cluster.The protonations of a variety of boranes and carbaboranes have been studied via MNDO calculations (and for 1,6-C2B4H6 uia ab initio MO calculations 3-21G basis set).I3' The site of localization of the HOMO of the substrate is that attacked this affording protonation of BBB triangular faces (e.g. in 1,12-C2BloH,2) of B-B edges (e.g. in &,HI') protonation resulting in a 3c-BH2 bond (e.g. in B2H6) or a 2c-BH bond (in [B4H4I2-) and protonation at carbon (generating a 2c C-H bond) in 1,5-C2B3H5 and 2-CB5H9. MNDO MO energies for closo-borane dianions and closo-carbaboranes have been linearly related to energy equations given by Stone's tensor surface harmonic (TSH) theory thereby lending support to the assumptions and utility of the TSH approach to cluster bonding.'32 The new hypho-species [B,H,PMe3]- has been prepared,'33 as its potassium salt by reaction of KB4H9 with PMe, and n.m.r.data have been interpreted in terms of a structure represented by the localized bonding description (50). This study I29 D. J. Fuller and D. L. Kepert Polyhedron 1983 2 749. 130 C. E. Housecroft and K. Wade Inorg. Chem. 1983 22 1391. 131 R. L. DeKock and C. P. Jasperse Inorg. Chem. 1983 22 3843. 132 P. Brint J. P. Cronin E. Seward and T. Whelan J. Chem. SOC.,Dalton Trans. 1983 975. I33 M. Shimoi and G. Kodama Inorg.Chern. 1983 22 1542. A. J. Welch prompted a thorough investigation of the reaction of B4H10 with phosphine in donor solvent; when molar equivalents of Me3P and B4H,0 react in THF at low tem- peratures Me3P.BH3 THF.B3H7 and [(THF),BH,]+[B,H,]-are mainly pro-d~ced,’~~ not Me3P.B3H7 and THFeBH,. The observed products are discussed in relation to cleavage mechanisms of B4Hlo. Stepwise addition of PMe3 to to form the belt-shaped B6Hlo.2PMe3 was described two years ago and now reaction of this with excess of phosphine has been re~0rted.l~~ Although complete separation of the reaction products has not been possible spectroscopic study suggests that the belt structure is cleaved to afford B2H4-2PMe3 B,H6.4PMe3 and two equivalents of B3H5 .3 PMe,.“B and 2H n.m.r. experiments have defined two relatively low-energy pathways for Lewis-base catalysed hydrogen exchange in XB5H8 molecules the energetically more favourable one involving scrambling of basal-terminal and bridge H atoms and the other involving exchange of H and migrating substituents (e.g. X = Me,Si) between basal and apical positions. It is argued that the latter pathway probably does not proceed via a simple 1,2-~hift.‘~~ The coupling of B5H9 with alkenes under mild conditions to afford good yields of 1-and 2-substituted alkenylpentab~ranesl~’ is catalysed by PdBr, whilst PtBr catalyses’38 the self-coupling of B,H9 to 1 :2’-( B5H8)2. Interestingly no evidence was found for the co-formation of either 1 1’-(B,H8) or 2:2’-(B,H,),.The lithium salt of the latter isomer has been assessed as an alternative precursor to [BsH8]- for polyhedral expansion syntheses.139 Reaction with B2H6 followed by acidification affords B,0H14 and more importantly n-B9H13 via the mechanism (suggested by isotopic enrichment experiments) of Scheme 2 i.e. bridge attachment of BH3 fol- lowed by polyhedral reduction and subsequent interaction of B5 and pendant B units. Interatomic distances in inter alia [B9H9I2- B&19 and C2B7H9 have been in relation to the non-degeneracy of the frontier orbitals of the parent borane uiz. [B,H,]’-. The ten-vertex thiaborane 6-SB9H1 is an unusual example of a polyhedral hydro- boration reagent and it has recently been shown that multiple hydroborations may be achieved with it.14’ Thus 6-SB9H, reacts with excess cis-hex-3-ene to afford 9-monohexyl 1,9-dihexyl and 1,3,9-trihexyl derivatives in multiple hydroboration reactions that appear to be reversible.Preliminary results indicate that 6-SB9H1 I34 M. Shimoi and G. Kodama Inorg. Chem. 1983 22 3300. 135 M. Kameda and G. Kodama Polyhedron 1983 2 413. ‘36 J. A. Heppert and D. F. Gaines Inorg. Chem. 1983 22 3155. 13’ T. Davan E. W. Cocoran jun. ahd L. G. Sneddon Organomefallics 1983 2 1493. 13* E. W. Corcoran jun. and L. G. Sneddon Inorg. Chem. 1983 22 182. ‘39 A. M. Barriola Acta Cient. Venez. 1983 34 25. 140 M. E. O’Neill and K. Wade Polyhedron 1983 2 963. 141 N. Canter C. G. Overberger and R. W. Rudolph Organometallics 1983 2 569. Boron 39 Reagents i MeLi; ii B,H,; iii H' Scheme 2 (Reproduced by permission from Acta Cient.Venez. 1983 34,25) reacts with polybutadiene to produce a cross-linked polymer. 6-SB9Hl and its selenium analogue reactI4* with alkyl isocyanides to form two isomeric adducts for which structures (5 1) and (52) are proposed. Whereas (5 1) is relatively stable (52) undergoes cage insertion of the ligand C atom to afford the nido-1 1-vertex thia- or selena-carbaborane (53). RN \ NR (51) (52) (53) Degradation-insertion reactions of BIOHI4 have been discussed by Base,143 and thus routes to a number of medium-sized aza- selena- and thia-boranes (including 6-SB9HI are summarized (Scheme 3). The crystal structure of 2-Br-6,9-(SMe2),- BloHl has been reported,I4 and although the molecular structure itself is relatively uninteresting (albeit the first example of optical isomerism in a decaborane deriva- tive) its solution is meritorious in that tetragonal twinning of orthorhombic lattices I42 A.Arafat G. D. Friesen and L. J. Todd Znorg. Chern. 1983 22 3721. I43 K. Base Collect. Czech. Chern. Comrnun. 1983 48 2593. V. Petricek 1. Cisarova and V. Subrtova Acta Crvstallogr. Sect. C 1983 39 1070. A. J. Welch 1 NaN02,THF 1. KHS0,.H20 2.conr. WlS04 1 conc. H250 \KH SO].H~O 0 BlQH14 6-SBpHI1 tI Il..Na2St03 2 dil HCl .THF\ 2.811. HCI SOIUl ;c n L 4-NBgHl3 9-L-6-NB9H12 6-NB9H13 Scheme 3 (Reproduced by permission from Collect. Czech. Chem. Commun.,1983 48 2593) was unravelled.Reaction with alkynes of the non-brominated species BloH ,,(SMe,) is a standard synthetic route to dicarbaboranes in which it has been proposed that BI0Hl2SMe2 (whole structure is unknown) is an important intermediate. It has recently been however that the unique 6,9-bridged phosphido-species ar~chno-[B,~H,~PPh~]-(54) may provide a structural analogue for BIoH,,SMe2. The only closo-borane dianion in the series [BnHnl2- (n = 6-12) for which neither a solid-state nor a limiting solution structure is known is [BIlHll]2- the only structural information available being that which relates to a derivative or to heteroborane analogues. This list has been recently supplemented by crystallographic and n.m.r. study14" of [B ,HlOSMe2]- shown to have the expected octadecahedral architecture (55) in which the SMe function is bound to B-4.1 2 3 8 9 I45 M. A. Beckett and J. D. Kennedy J. Chem. Soc. Chem. Commun. 1983 575. I46 E. H. Wong L. Prasad E. J. Gabe. and M. G. Gatter Inorg. Chem. 1983 22 1143. Boron 41 The subhalides of boron have been reviewed by Massey.14’ A re-e~amination’~~ of the thermal decomposition of [H30]2B10C110 has shed light on a previous anomaly in born subhalide chemistry viz. the IlB n.m.r. spectrum of ‘HB9Cls’ whose four resonances (one split by H) could not be reconciled with the expected tricapped trigonal prismatic structure. In reality ‘HB,Cl,’ is a mixture of HB9C18 H2B9C17 and BgC19. Also produced in the decomposition study are BloCllo BllClll and BI2Cll2 as well as the entire range of supraicosahedral subhalides B,Cl (n = 13-20).Unfortunately it has not yet proved possible to separate these. 7 Metallaboranes and Derivatives Deuterium labelling experiments have been used to study the (Ph3P),CoC1-activated hydrogenation of diphenylethyne by NaBH,. Typically after prior reaction in THF the mixture is acid hydrolysed and although the major source of the vinylic H atoms in the cis-and trans-stilbene formed is the BH4- ion a minor source must be the s01vent.I~~ The reaction presumably proceeds via formation of a Co-BH complex. Reductive hydrogenations of C02 and COS to (R,P),Co( q2-0,CH) and (R3P),Cu( q2-OSOH) respectively and of SCNPh to (R,P),Cu( q2-S2CNHPh) by q2-BH,) (R = Ph or cyclo-C6H1 have been in~estigated,’~’ (R3P)2C~( and novel q’-bonded terminal and bridging formate complexes result from addition of one equivalent of PPh3 to the C02-Ph3P system.Addition’” of excess phosphite to {(R0)3P}2Cu(q2-H3BC02Et) (56) (R = Me or Et) affords ultimately the ionic species [{(R0),P},Cu]+[H3BC02Et]-. Analysis of ‘H n.m.r. data for (56; R = Me) has allowed AG’ for the fluctionality (bridge- terminal hydrogen exchange) of {(MeO),P),Cu( q2-BH4) to be estimated as 4.3 kcal- mol-’. It is proposed that this value is less than that for (T-C~H~)~V(~~-BH,) because of the greater degree of covalency in the M-H-B bridge system of the latter.lS2 A Ta-H-B bridge exists in the bis(pyrazoly1)borate complex {H2B(3,5- Me,pz),}TaMe,Cl (57). Although H-1 1 was not located in a crystallographic study the stereochemistry at Ta and short Ta-B distance 2.897( 12) A are consistent with its presumed position and moreover i.r.and coupled ’’B n.m.r. spectra (the latter up to 110 “C) imply its existence and thermodynamic ~tabi1ity.l~~ A most unusual mode of BH co-ordination has been established in Co2( BH4)2{ Ph2P(CH2),PPh2) (58) structurally studied as its 0.5 C6H6 s01vate.I~~ All hydrogen atoms attached to boron were located and refined. The BH units are both tridentate and bridging (this work represents the first structurally proven example of bridging BH,) and the existence of three chemically different types of BH hydrogen atom is fully supported by i.r. spectroscopy. To distinguish bridging and multidentate A.G. Massey Adv. Inorg. Chem. Radiochem. 1983 26 1. I48 D. A. Saulys N. A. Kutz and J. A. Morrison Inorg. Chem. 1983 22 1821. I49 E. Steinberger M. Michman H.Schwarz and G. Hohne J. Organornetal. Chern. 1983 244 283. I so C. Bianchini C. A. Ghilardi A. Meli S. Midollini and A. Orlandini J. Organornetal. Chern. 1983,255 C27. Is’ J. C. Bommer and K. W. Morse Inorg. Chern. 1983 22 592. IS2 J. C. Bommer and K. W. Morse Inorg. Chirn. Acta 1983 74 25. IS3 D. L. Reger C. A. Swift and L. Lebioda J. Am. Chem. Soc. 1983 105 5343. IS4 D. G. Holah A. N. Hughes S. Maciaszek and V.R. Magnuson J. Chem. SOC. Chern. Commun. 1983 1308. A. J. Welch (57) (Reproduced by permission from J. Am. Chem. SOC.,1983 105 5343) (Reproduced from J.Chem. SOC.,Chem. Commun. 1983 1308) co-ordination of BH4 we shall in this year's Report adopt p for the former and V" for the latter. In {q-C5H3(SiMe3)2}2(THF)nM(BH4) (M = Sc n = 0; M = Y or Yb n = 1) the BH moiety is T2-co-ordinated whereas in analogues of larger metals (M = La Pr Nd or Sm n = 1) it is q3-bound. IlB N.m.r. spectroscopy reveals that for the Sc complex only the BH4 co-ordination is relatively static.'55 Since this is the only I55 M. F. Lappert A Singh J. L. Atwood and W. E. Hunter J. Chem. SOC.,Chem. Commun. 1983 206. Boron 43 member of the series that is not solvated it is possible that in those cases where fluctionality (bridge and terminal H exchange) occurs it does so via a 7'-bonded intermediate whose relative electron deficiency is mitigated by co-ordinated THF.Anionic tetrakis(tetrahydrob0rate) complexes of Gd Tb Dy Ho Er Tm Yb and Lu have been reported,156 and i.r. study suggests that the first two of these contain q3-BH4 and p-(q2)*-BH4functions whereas for the heavier elements simple 773 -co-ordination occurs. An accurate low-temperature neutron diffraction studyI5' of H~(T~-BH~)~ (59) affords parameters Hf-Hb 2.130(9) B-Hb 1.235( lo) and B-HH 1.150(9) A; HfHB 80.6(6)".X-Ray studies of M(q3-BH3Me) (M = Zr Np U or Th) have also been rep~rted;'~~ not surprisingly only for the zirconium analogue could H atoms be refined yielding (Zr-H) 2.06A (B-H) 1.14A. The Zr and Np species are isomorphous and the U and Th compounds are separately nearly isomorphous.1.r. and n.m.r. data (reported for all except the Np analogue) are in full accord with v3-co-ordination. (Reproduced by permission from Inorg. Chern. 1983 22 1081) Full details have now been p~blisedl~~ of the structure of [NaBHMe,],-Et,O which has a very distorted pseudo-cubane Na4H4 core ((H-a-H) 2.73 A (Na-m-Na) 3.611 A) with closest Na-H distances between 2.25 and 2.42 A. (B-H) is 1.20(7) A. Grimes has reviewed the role of transition metals in borane and carbaborane clusters with particular emphasis on the cluster stabilization that the metal affords and metal-promoted coupling fusion and intramolecular hydrogen transfer reac- tions. I6O The overall result of reaction of H20s3(CO),o with BH3NEt3 and 0.5 B2H6 is insertion of a boron atom into an Os-CO bond to yield the carbonyl borylidyne I56 V.D. Makhaev A. P. Borisov B. P.Tarasov and K. N. Semenenko Zh. Neorg. Khim. 1983 28 340. 157 R. W. Broach 1.4. Chuang T. J. Marks and J. M. Williams Inorg. Chem. 1983 22 1081. 158 R. Shimomoto E. Camp N. M. Edelstein D. H. Templeton and A. Zalkin Inorg. Chem. 1983,22,2351. 159 N. A. Bell H. M. M. Shearer and C. B. Spencer Acta Crystallogr. Sect. C 1983 39 694. 160 R. N. Grimes Acc. Chem. Rex 1983 16 22. A. J. Welch species (60) in which the BCO unit face bridges the metal triangle.I6' A mechanism is proposed in which it is the borane-amine adduct that affords the BH unit that is the net addition to the metal substrate. 0 22 13 (Reproduced by permission from J.Am. Chem. SOC.,1983 105 5923) Preliminary details of the ferraborane HFe,(CO) 12BH2 were reported last year. Full structural information and a thorough discussion of this cluster have now been published.162The application of simple electron counting procedures to this molecule is ambiguous but the narrow (1 14") dihedral angle between Fe3 triangles suggests classification as an arachno Fe cluster with interstitial boron atom (or in Mingos- Lauher terms a 62 electron saturated cluster). This view is supported by the results of Fenske-Hall MO calculations which have also rationalized the observed orienta- tion of the BH2 fragment and which suggest that deprotonation of the molecule would occur by loss of a boron-bonded H. Fenske-Hall calculations have also been employed'63 to aid assignment of the UVPE spectrum of ( q-C,H,) (C0)2Fe(B2H,) (61).Analogy is made between the [B2H5]-ligand of (61) and the C2H ligand of Fe(C0)4(C2H,); [B2H5]- is regarded as q2-[B2H4I2- protonated on the opposite side of the B-B bond to the metal atom. EHMO calculations are then used to analogize higher boranes with appropriate r-bonded hydrocarbons attention being focused on the role of bridging H atoms of the former in reorientation of ligand r-orbitals. The important point is made however that borane ligands are generally less good at stabilizing low oxidation state metal centres because of their limited T-acceptor capability. S. G. Shore D.-Y. Jan L.-Y. Hsu and W.-L. Hsu J. Am. Chem. SOC. 1983 105 5923. '62 T. P. Fehlner C.E. Housecroft W. R. Scheidt and K. S. Wong Organometallics 1983 2 825. R. L. DeKock P. Deshmukh T. P. Fehlner C. E. Housecroft J. S. Plotkin and S. G. Shore J. Am. Chem. SOC.,1983 105 815. Boron 45 The complement to this of course is that boranes should be quite appropriate ligands for high oxidation state metals and Greenwood and colleagues have pre- viously utilized this feature to prepare metallaboranes with formal valencies as high as +5. In 1983 the scope of the synthetic program of the Leeds group has been widened to include the first osmaboranes. Thus Os(CO)(Cl)( H)( PPh,) reacts with [B3H8]- and [B,H,]- to afford164 (HOsB,H,)(CO)(PPh,) (62) and (OsB,H,)(CO)- (PPh3)2 (63) for which the structures shown are proposed on spectroscopic grounds.[B,H,]-also reacts with IrCl( PPh,) to yield (H21rB,H8)(PPh,), structurally similar to (62). Mild thermolysis (100 "C C,Cl,) of (63) affords (OsB,H,)(CO)(PPh,) for which the nido structure (64) is suggested. An osmaborane intermediate is impli- cated16 in the edge-fusion of nido-[B,H,,]-polyhedra to yield anti-[B,,H21]- under CH2CI2 reflux in the presence of [Os(CO),CI],. (64) (Reproduced by permission from J. Organometal. Chem. 1983 249 11) The same group of workers has additionally synthesized heterobimetallic metal- laboranes starting with a nido-metallaborane and with it performing analogous reactions to those of nido-boranes. Thus 6-( Ph,P)-6-( Ph2P-2'- C6H4)-6-H-nido-6-IrB,H12-j (65) (analogue of B,0H,4) may be treated166 with KH and then cis-PtCl,(PMe,) to yield 7,7-( Me,P),-9-( Ph,P)-9-( Ph,P-2'- C6H4)-9-H-nido-7,9-PIrB9H10-~(66).Similarly (63) with NaH then cis-PtC12(PhMe2P) yields167 (Ph3P),(CO)0s(PhMe2P)ClHPtB5H7(67; p-H not directly located) and here (63) is a surrogate for B&il,. Products (66) and (67) with different 164 J. Bould N. N. Greenwood and J. D. Kennedy J. Organometal. Chem. 1983 249 11. 165 J. Bould N. N. Greenwood and J. D. Kennedy Polyhedron 1983 2 1401. 166 J. Bould J. E. Crook N. N. Greenwood J. D. Kennedy and W. S. McDonald J. Chem. Soc. Chern. Commun. 1983 949. 167 J. Bould J. E. Crook N. N. Greenwood and J. D. Kennedy J. Chem. Soc. Chem. Commun. 1983,951. A. J. Welch (65) (Reproduced from J. Chem. SOC.,Chem. Commun. 983 949) metal atoms connected via a boron cage have been termed 'B-frame compounds' and their synthesis and subsequent structural elucidation sheds possible light on the mechanisms of polyhedral expansion reactions ;for example on following the position of the ortho-phenylene function in the synthesis of (66) from (65) it is evident that polyhedral isomerization has occurred.From the analogous reaction of BIDHI4 one could not easily establish this (although of course these 'analogous' reactions may follow different paths). (67) (Reproduced from J. Chem. Soc. Chem. Commun. 1983 951) The structure of the macropolyhedral 17-vertex platinaborane (PhMe,P),- Pt3B14H16 has been determined,'68 and three views of it (whole molecule minus H atoms additionally minus phosphine ligands and additionally minus metals) are given in (68).B(1I) does not have a terminal H and bridging H atoms are ascribed M. A. Beckett J. E. Crook N. N. Greenwood and J. D. Kennedy J. Chem. SOC.,Chem. Commun. 1983 1228. Boron 47 to B(4’)-B(5’) B(4’)-B(9‘) and the Pt(7,6)B(8)B(9)Pt( 10,8‘) sequence. It is sug- gested that the macropolyhedron be viewed as nido 11-vertex (unprimed atoms) and arachno 9-vertex (primed atoms) polyhedra fused about their common PtBPt face. (68) (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 1228) 8 Carbaboranes and Carbametallaboranes Onak and co-workers have accurately remeasured ‘J(BH) for the entire range of known closo-carbaboranes C2Bn H2+, (n = 3-1 0) and have established an empirical correlation between J the appropriate ‘umbrella’ angle (the average interior angle of a cone in the polyhedral surface whose apex is the boron atom clearly related to the s-character of the exopolyhedral B-H bond) and the number of adjacent cage carbon atoms.’69 Good agreement occurs for all species except 1,7-C2B,H (probably fluctional in solution) and 1,6-C2BsHlo (incomplete data and assignments).The utility of this method is demonstrated in that it has facilitated complete assignment of the chemical shifts in 2,3-C2B9H1 1. A re-examination of the gas-phase pyrolysis of 1,5-C2B3H5 has verified the pre- viously reported formation of the B-B linked dimer 2:2’-( 1,5-C2B3H4)2 and trimer 2:2’,3‘:2”-(1,5-C2B3H4)( 1’,5’-C2B3H3)( 1”,5”-C2B3H,) and has also identified the new species 1:2’-( 1,5-C2B3H4)2 (69) 2:2’,1’:2”-( 1,5-C2B3H4)( 1’,5’-C2B3H3)- ( 1”-5”-C2B3H4) (70) 2:2’,3’ 1”-(1,5-C2B3H,)( 1’,5’-C2B3H3)( 1”,5”-C2B3H4) (71) and 1,2,8,1 0-C4B7HI (72) for which the structures shown are proposed on spectroscopic ground^."^ (69)-(71) all contain B-C intercage linkages and (70) is especially I69 W.Jarvis Z. J. Abdou and T. Onak Polyhedron 1983 2 1067. R.J. Astheirner and L. G. Sneddon Inorg. Chem. 1983 22 1928. A. J. Welch (71) (72) (Reproduced by permission from Znorg. Chem. 1983 22 1928) interesting in that the linkages are perpendicular. The mechanism of formation of (72) is unclear. Pyrolysis of 1,6-C2B4H6 affords only polymerization but co-ther- molysis of it and 1,5-C2B3H5 yields 2’:2-( 1’,5’-C2B3H4)( 1,6-C2B4H5) in improved yields compared with its previous photochemical production.It had previously been established that reaction of (q-C,H,)Co(CO) with an isomeric mixture of the linked carbaborane (2,4-C2B5H6)2 affords six isomeric carbametallaboranes and now structural study of one of these (73) reveals it to be Le. 3’:2(2‘,4‘-C,B,H,)( 1,8-{ q-C,H,),-1,8,5,6-Co2C2B5H6),a tricapped (B + 2C) trigonal-prismatic carbadicobaltaborane linked to the pentagonal-bipyramidal car- baborane via a B(2)-B(3’) bond.”’ Q (Reproduced by permission from Inorg. Chem. 1983 22 1765) A new route to the B-B-linked bis(carbaborane) (Me2C2B10H9)2 has been repor- ted oxidation of 1,2-Me2-1 ,2-C2B10HI0 with T1(02CCF3)2 in the presence of 10% Pd(OAc) affording the product in 35% ~ie1d.I’~ A reasonable (10%) yield of ~so-C~B,~H~~ is produced by thermolysis (80 “C,benzene or toluene) of nido-7,8-C2B9H13.Analyses of the mass spectrum and of the proton and IlB n.m.r.spectra R. P. Micciche J. S. Plotkin and L. G. Sneddon Znorg. Chern. 1983 22 1765. 172 A. Ya. Usyatinskii A. D. Ryabov T. M. Shcherbina V. I. Bregadze and N. N. Godovikov Izu. Akad. Nauk SSSR Ser. Khim. 1983 1637. Boron 49 of iso-C4BaHl confirm that it comprises a closed 1,2-C2BI0H1 icosahedron linked to a nido-5’,6’-C2BaH1 octadecahedral fragment by a B(3)-B(8’) bond.173 Arene carbametallaboranes have been the subject of recent research activity since their initial synthesis in 1981. The major product of the co-condensation of iron atoms toluene and nido-2,3 -Et2-2,3-C2B4H6 is174 the closo pentagonal-bipyramidal species 1-(q6-PhMe)-2,3-Et2-l ,2,3-FeC2B4H4 (74) (for which a crystallographic study is reported) although mass spectrometric evidence for iron-C4B7 and -C4Bg complexes is also given.Alternatively 1-( q6-CaHlo)-2-3-Et2-1,2,3-FeC2B4H4(75) (produced’75 by reaction of [C8Hs12- FeCl, and [Et2C2B4H5]-) reacts with arene over AlC13 to yield aAalogues of (74) (arene = C6H6 1,3,5-Me&H3 or C6Me6) all species being characterized by i.r. and multinuclear n.m.r. spectroscopies mass spectrometry and X-ray diff ra~ti0n.l~~ Co-produced with (75) are rather surpris- ingly its q6-C6H6 analogue and (Cl6HIa)Fe( ; spectroscopic data are Et2C2B4H4) given for the latter but there is no structural a~signment.’~’ (75) characterized by an X-ray study of its 2,3-Me2 analogue also reacts’76 with tetramethylethyl- enediamine to abstract the unique equatorial boron atom and afford (q6-c8H10 Fe( Et2C2 B3 H5 -If VCl replaces FeC1 in the reaction that produces (75) the result17’ is the q8-bonded cyclo-octatetraenyl species 1-(q8-CaHa)-2,3-Et2-1,2,3-VC2B4H4 (76) a unique compound in that it is the first example of q8-bound CsHa to a first transition series element other than Ti.The species is electron deficient in that (assuming a formal [CgH,]’- exopolyhedral ligand) it either has 2n + 2 cluster bonding electrons (n = 7) and a 17e metal centre,. or only 2n + I cluster electrons at variance with the predictions of the Polyhedral Skeletal Electron Pair (PSEP) theory and an (76) (Reproduced by permission from J.Am. Chem. Soc. 1983 105 2079) I73 2. Janousek J. Plesek B. Stibr and S. Hermanek Collect. Czech. Chem. Commun. 1983 48 228. I74 R. P. Micciche and L. G. Sneddon Organometallics 1983 2 674. I75 R. B. Maynard R. G. Swisher and R. N. Grimes Organometallics 1983 2 509. I76 R. G. Swisher E. Sinn and R. N. Grimes Organometallics 1983 2 506. R. G. Swisher E. Sinn G. A. Brewer and R. N. Grimes J. Am. Chem. SOC.,1983 105 2079. A. J. Welch electronically saturated vanadium atom. A preference is expressed for the former; see also the discussion of compounds (81) (90) and (91). In attempting to.extend the chemistry of closo-5-C1-C2B5H6 (some details of which were reported last year) to the bromo analogue Onak and Fuller have found178 that Me3N.5-Br-C2B5H undergoes halogen exchange with CH2C12 affording 5-C1-C2B5H6 and [Me3NCH2Cl]Br presumably via a [5-Me3N-C2B5H,]+ intermediate.The eight-vertex carbacobaltaborane 3-(77-C5H5)-1,2-Me2-3,1,2-CoC2B5HS has a dodecahedra1 cage geometry with the metal atom (five-connected with respect to the cluster) and carbon atoms (four-connected) constituting one face. 179 Three closo ten-vertex (bicapped square antiprismatic) monocarbon carbametal- laboranes have been separately reported. In [2-(77-C5H5)-2, l-CoCB,H,]- struc-turally studiedlBO as its NMe,+ salt and in p-1,2-(MeC02)-2-H-2,10-(PPh3)2-1 ,2-CIrB,H (77) (formed,lB1 in <I% yield by refluxing [BloH,o]2- with trans-Ir(CO)Cl(PPh,) in MeOH) the metal atoms are five-connected and adjacent to a carbon cap This contrasts with I ,2,2-( PPh3)3-2-H-2,10-IrCB8H8(78) in which the heteroatoms are separated although (77) and (78) share the common feature that it is the four-connected boron atom to which the PPh3 ligand is bound.(78) is one (77) Terminal H atoms on boron atoms and on Ir(2) not shown (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 83) 178 K. Fuller and T. Onak J. Organometal. Chem. 1983 246 C6. 179 G. J. Zimmerman and L. G. Sneddon AC~Q Crystallogr. Sect. C 1983 39 856. I80 K. A. Solntsev L. A. Butman I. Yu. Kuznetsov N. T. Kuznetsov B. Stibr 2.Janousek and K. Base Koord. Khim. 1983 9 993. J. E. Crook N. N. Greenwood J.D. Kennedy and W. S. McDonald J. Chem. SOC.,Chem. Commwn. 1983 83. Boron 51 of several products of the reactions between [CBgH13]- and IrCl(PPh,), and a possible mechanism is discussed.Ig2. The B-H-B functions of nido-5,6-C2BgH12are sufficiently electrophilic to react with Pt2(p-C,H12) (PEt,) to yieldlg3 9-H-9,9-(Et3P)2-p,0,1 -H-7,8,9-C2PtB8Hlo (79) a nido-icosahedral formally PtIV species. Upon thermolysis (79) evolves one molar equivalent to H2 in being transformed into 9-H-9,10-( Et3P),-7,8,9-C2PtB8H9 (80) (79) In (79) there is a p-H between B(10)and B(11) (Reproduced from J. Chem. Soc. Dalton Trans. 1983 2063) which could be considered a very distorted octadecahedral cluster with a formally +2 oxidation state metal atom since one phosphine ligand has transferred from Pt(9) to B( 10).Nido-5,6-C2B8H12 also reacts with (T-C~H,)~N~ to affordlg4 the nido-carbanickellaborane(8 1) crystallographically studied as thus and in derivative form (82) in which the remaining bridge hydrogen atom is replaced by the isolobal AuPPh fragment. (q-CgH5)2Cr is apparently more reactive towards the same nido- carbaborane since the only product isolated from their reaction is the dimetal species (83) [presumably formed via an intermediate similar to (Sl)]. This overall set of reactions is summarized in Scheme (4). (8 l) too was identified crystallographically and contains the shortest metal-metal distance 2.272(2) A yet recorded in a heteroborane cluster a feature that has been reproduced by EHMO calculations.The electron count in (8 1) is interesting in that the polyhedron is electron deficient (in the PSEP sense) by 6e if one requires that the (q-C,H,)Cr fragment is a le acceptor thereby satisfying the 18e rule. However if the valence electron count is only 15 (‘fZR’ orbitals singly occupied) then the cluster is precise (again in PSEP terminology) and the deficiency resides on the metals. A similar situation has arisen previously [compound (76)] and is met later in this section [compounds (90) and (91)]. In simple terms the ‘multiple’ Cr-Cr bond in (81) is the result of bonding interactions between these sets of adjacent singly occupied metal atomic orbitals. N. W. Alcock J. G. Taylor and M. G. H. Wallbridge J. Chem. Soc. Chem. Cornmun.1983 1168. I83 G. K. Baker M. Green F. G. A. Stone W. C. Wolsey and A. J. Welch J. Chem. Soc. Dalton Trans. 1983 2063. I84 G. K. Barker N. R. Godfrey M. Green H. E. Parge F. G. A. Stone and A. J. Welch J. Chem. Soc. Chem. Cornmun. 1983 277. A. J. Welch Reagents i (~pc~H~)~Ni; ii MeAuPPh,; iii (~pC~H~),cr Scheme 4 (Reproduced from J. Chem. Soc Chem. Commun. 1983 277) 1,2-C2BloH has been reported revealing The crystal structure of p8,8f-SCH2S-( the presence of two conformers in the solid state (2= 4 in space group P21) differing in the magnitude of the torsion angle about one of the S-C bonds.I8’ The icosahedral carbaborane cages are quite normal ((C-C) 1.598A (C-B) 1.672 A (B-B) 1.755 A) and the mean B-S (exopolyhedral) distance is 1.871 A.Anionic icosahedral bis(1igand)carbarhodaboranes with 3,l ,2-RhC2 2,l ,7-RhC2 and 2,1,1 2-RhC2 heteroatom substitution patterns have been produced by proton abstraction from their neutral hydride analogues,186,* and the bis(tripheny1phos- phine) members of the first two types structurally characterized. The conformations adopted by the (Ph,P),Rh’ fragments resemble those previously established for (R3P)2Pt11fragments although the rhodium species do not display the slipping distortions that characterize (especially the 3 I ,2-PtC2) platinum compounds. In C. Novak V. Subrtova A. Linek and J. Hasek Acta Crystallogr. Sect. C 1983 39 1393. I86 J. A. Walker C. B. Knobler and M. F. Hawthorne J. Am. Chem. SOC.,1983 105 3368. * There appears to be a type-setting error in the paper that could lead to confusion.Presumably the 2nd line of the 2nd paragraph should read ‘3,1,2-RhC2BPH (I a)’ only. Boron 53 solution there is hindered rotation about the metal-cage axis. These bisphosphine species are readily converted into phosphine/carbonyl complexes [(Ph,P)-(CO)RhC2B9H11]-,and it is argued i? a following comm~nication'~~ that the formal description (Ph3P)(C2B9HI,)Rh2-C=0 might lead to [3 + 21 cycloaddition reac- tions with 1,3-dipolar substrates. This does indeed happen cycloadducts being obtained by reaction with benzhydroxamic acid chloride or its rn-fluoro-derivative ; a crystal structure of the anion (84)obtained from the latter acid chloride and the 2,1,7-RhC2 cage shows bond lengths consistent with C=N and (exocyclic) C=O double bonds.TheCe cycloadducts readily lose C02 (and benzonitrile or rn-fluorobenzonitrile) on warming and the possibility of using this strategy to decar- bonylate metal complexes under relatively mild conditions is discussed and one example given. This is clearly an important piece of transition-metal chemistry with implications outwith the specific area of boron clusters. (Reproduced by permission from J. Am. Chem. Soc. 1983 105 3370) 3,3-( Ph3P)2-3-H-3,1 ,2-RhC2B9H1 is also the precursor for [HPPhJ-[3-Ph3P-3,3-Br2-3,1,2-RhC2B9H, isolated as the tight ion pair shown in (85) by reaction188 of the neutral carbarhodaborane with BBr,. Nim.r. data suggest that two rotational conformers of the anion exist in solution that displayed by the X-ray study (asymmetric) and a symmetric alternative (which predominates at high tem- peratures) in which the phosphorus atom lies on the cage mirror plane cisoidal to C( 1) and C(2).Ligand interchange [phosphine for H(8) i.e. formation of Ni-H and B(8)-P bonds from Ni-P and B(8)-H bonds] as a consequence of heating 3,3-(Ph,P),- 3,1,2-NiC2B9H1 has been known for some years but now a re-investigati~n'~~ of the system (various phosphines various isomers) has established that it only occurs for triarylphosphine complexes and only for the 3,l ,2-NiC2 isomer. A mechanism is proposed that involves dissociative loss of free phosphine which subsequently attacks B(8). As a complement to these studies ligand dissociation and substitution reactions of the 3,3-( PR3) species and reactivity studies of the 3,8-( PR3)2 species are also reported.The new complex (86) was prepared by a number of routes and 187 J. A. Walker C. B. Knobler and M. F. Hawthorne J. Am. Chem. SOC. 1983 105 3370. 188 L. Zheng R. T. Baker C. B. Knobler J. A. Walker and M. F. Hawthorne Inorg. Chem. 1983,22 3350. I89 R. E. King 111 S. B. Miller C. B. Knobler and M. F. Hawthorne Inorg. Chem. 1983 22 3548. A. J. Welch B ? eI II (85) (Reproduced by permission from Inorg. Chem. 1983 22 3350) (86) (Reproduced by permission from Znorg. Chem. 1983 22 3548) has been studied crystallographically. The two icosahedral cages are linked by a Ni-Ni bond which is doubly bridged by carbonyls.Two quite different further examples of joined carbarhodaborane icosahedra have been reported by the same group. Reaction of FU-iCl(PPh,) with nido-B10C12CNH3 which is and base affords [2,2-(PPh3)2-2-H-1-NH2-2,1-RhCB,oH,o]-transformed in hot methanol into the dimeric anion (87) structurally studied as its [Bu,N]+ ~a1t.I~' In (87) there are three links between the icosahedra one Rh-H-Rh' I90 .I.A. Walker C. A. O'Con L. Zheng C. B. Knobler and M. F. Hawthorne J. Chern. SOC.,Chem. Commun. 1983 803. Boron 55 (87) (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 803) (Reproduced by permission from Angew. Chem. 1983 95 738) and two Rh-NH,-Cl’. The Rh-Rh distance is 2.998( 1) A There are four connections between the icosahedra of [(Et3P)RhC2B9HI1],(88) uiz.a direct Cl-C1’ bond a direct Rh(3)-Rh(3’) bond 2.725( 1) A and two three-centre Rh(3)-H(4‘)-B(4’) (and complement) bonds.’” (88) is produced in moderate yield by the reaction between (v4-C8HI2)Rh(PEt3)C1 and the caesium salt of the bis-( nidu-carbaborane) [C2B9H1 1]22- in which the Cl-CI’ link already exists. P.E. Behnken C. B. Knobler. and M. F. Hawthorne Angew. Chem. 1983 95 738. A. J. Welch The (known) bis(carbaborane) complex [Fe(C2B9H1 has been synthesized electrochemically’92 using nido-[C2B9H 12]-in NaBr-DMSO and an iron electrode. Its neutral platinum analogue (previously unknown to this reporter although the corresponding NilV and PdIV species are well documented) is afforded by treatment of nido-C2B9H, with chloroplatinic acid in isopropyl Volkov Dvurechen- skaya and co-workers have published two further paper^'^^,'^^ on multiply linked carbacobaltaborane polyhedra [(C2B9HI l){Co( C2B8H 10)}nC~C2B9H to complement the existing literature We complete this section by discussing two papers concerned with supraicosahe- dral carbametallaboranes i.e.the cluster is or is a fragment of a closed polyhedron of more than 12vertices. It has been impossible to synthesize such species by solution direct insertion using nucleophilic nickel-group fragments but now the higher reactivity of the Co(PEt,) fragment has been utilized196 to afford the closed 13-vertex complex (89) from direct insertion into 1-Me-1,2-C2B10H In addition to the polyhedral metal atom co(4) (which occupies the docosahedral vertex of highest connectivity) (89) contains an exopolyhedral Co( PEt,) unit bonded to the cluster by H-bridged Co-Co and Co(2)-B(7) bonds.(89) (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 137) I92 V. L. Shirokii A. A. Erdman Z. P. Zubreichuk N. A. Maier and Yu. A. Ol’dekop Zh. Obshch. Khim. 1983 53 951. I93 E. A. Chernyshev L. K. Knyazeva Z. V. Belyakova A. V. Kisin N. I. Kirillova A. 1. Gusev and N. V. Alekseev Zh. Obshch. Khim. 1983 53 1433. I94 S. Ya. Dvurechenskaya V. V. Volkov I. I. Gorbacheva and N. D. Krivosheeva Izv. Sib. Otd. Akad. Nauk SSSR Ser. Khim. Nauk 1983 74. I95 V. V. Volkov and V. N. Ikorskii Izv. Akad. Nauk SSSR Ser. Khim. 1983 252. I96 G. K. Barker M. P. Garcia M. Green F.G. A. Stone and A. J. Welch J. Chem. SOC. Chem. Commun. 1983. 137. Boron 57 Grimes and colleagues have previously synthesized open supraicosahedral car- bametallaboranes from the reactions of relatively electron-rich metals (Fe Co Ni) with &C4BsHs or its dianion (R = H or alkyl). As a complement to such studies these workers have now examined197 the behaviour of the relatively electron-poor ( q-CSHs)Cr fragment towards the four-carbon carbaborane R = Et. From reaction (CrC1,-C5H5-[Et4C4BaH8I*-) and work-up four species are identified two isomers of (~-C,H,)CrEt4C,BaH8 and two isomers of (7-C5HS)CrEt4C4B7H7. One of each pair (90) and (9 1) respectively have been characterised crystallographically. It is believed that (9 1) originates from metal reaction with a pre-formed C4B7 cluster and that the second CrC4B7 species (not studied crystallographically) is a degradation product of (90).(90) (Reproduced by permission from Inorg. Chem. 1983 22 873) (90) has an irregular open cage structure and (91) is also open but possesses an approximate molecular mirror plane. As previously discussed for (8 1) compounds (90) and (91) apparently violate PSEP theory if one necessarily assigns 18e configur- ations to the metal atoms but become reasonable in PSEP terms (2n + 4 framework electrons nido geometries as observed crystallographically) if electron deficiency -in this case 15e configurations only-of the metal centre is argued. Other similar examples involving transition metals from the left of the periodic table are known in the literature.9 Exopolyhedral Chemistry of Boranes and Carbaboranes Irradiation of ethyldiazoacetate-1 ,2-C2BloHI2 in C,F affords all four possible isomers of B-CH2C(0)OEt(C2BloHI through insertion of the carbene function CHC(0)OEt into B-H bonds of the ~arbab0rane.I~' Teixidor and have synthesized ligands containing either two cfoso-C2BloH, or two nido-C2B,Hg cages linked by the sulphur-containing chains S-S I97 R. B. Maynard Z.-T. Wang E. Sinn and R. N. Grimes Inorg. Chem. 1982 22 873. 198 G.-X. Zheng and M. Jones jm. J. Am. Chern. SOC.,1983 105 6487. 199 F. Teixidor and R. W. Rudolph J. Organometal. Chem. 1983 241 301. A. J. Welch or SCH2CH2S and SCH2S or SCH2CH2S respectively with the cage carbon atoms bound to the exopolyhedral sulphur atoms.When however cages were bridged by 1,2-( SCH2),C6H4 a polymeric product of uncertain order was obtained. Carbaborane cages exo to cyclic or polymeric phosphazenes were reported by Allcock and co-workers in 1980 and 1981 but such species do not afford metal derivatives presumably because of the proximity of the phosphazene to the open face of the nido polyhedron produced by base degradation. If however a CH spacer is inserted between P and cage C the desired products are attainable. Thus (92) affords (93) which appears to be protonated at the ring N opposite to the unique P [thus (93) is strictly a phosphazane] and via single or double deprotonations (93) serves as a source of q5-bonded carbaborane ligand (with exopolyhedral cyclic phosphazene) to suitable metal fragments.Alternatively prior pyrolysis of (93) affords highly polymeric derivatives analogous to those reported earlier but now with spacers and these too can be used to generate carbametallaboranes.200 I II Cl-PQ ,p-Cl c1/ \cl (92) (93) Tetrahedral dichlorocobalt complexes whose co-ordination spheres are ,completed by either two P(Ph2)C2B,,H, ligands or one P,P'-bidentate XzPC2BloHloPYZ ligand (X = Me2N Y = Z = Ph) have been synthesized:" the C2B,o fragment being 1,2-C2Blo in both cases. The same chelate ligand (with variations X = Ph Y = Z = Ph NMe, or F; X = Ph Y = NMe, Z = F; X = NMe, Y = Z = C,F,; X = NMe, Y = NMez Z = F) has also been utilized to afford a range of PtCl,(chelate) complexes.202 With RAX (R = Me or Ph A = P or As X = C1 or I) 1,2-(CH2MgBr),-1,2- C2B10H10undergoes exopolyhedral cyclization to yield P~,~-{CH,( R)ACHz}-1,2-C2B10HI0,from which A-bonded M(CO) (M = Cr Mo or W) derivatives are readily ~ynthesized.~'~ Rhodiumzo4 and platinum and palladium205 yomplexes have been described in which the metal is part of an exopolyhedral MB*C*CP ring (asterisked atoms are polyhedral) and which are similar to rhenium and manganese species reported in the past two years.In [B,oHlo]2- there exist two chemically different H atoms. It has been proposed that c~~-P~(PP~~)~(B~~H,~), formed by reaction between cis-Pt(PPh3),12 and 200 €3. R. Allcock A. G. Scopelianos R. R. Whittle and N. M. Tollefson J. Am.Chem. Soc. 1983 105 1316. 20 1 J. G. Contreras J. P. Pena and L. M. Silva-Trivino Bol. SOC.Chil. Quim. 1983 28 3. 202 W. E. Hill B. G. Rackley and L. M. Silva-Trivino Inorg. Chim. Acta 1983 75 51. 203 L. I. Zakharkin M. G. Meiramov V. A. Antonovich A. V. Kasantsev A. I. Yanovskii and Yu. T. Struchkov Zh. Obshch. Khirn. 1983 53 90. 204 V. N. Kalinin A. V. Usatov and L. I. Zakharkin Zh. Obshch. Khim. 1983 53 945. 205 V. N. Kalinin A. V. Usatov and L. I. Zakharkin J. Organometa!. Chern. 1983 254 127. Boron 59 (M+)2[B,oHloJ2-(M = K or Ag) exists as two dimers which differ in respect of the H atoms involved in Pt-H-B bridge bonds.206 [BloHlo]2- has also been reported to enter into inner-sphere co-ordination displacing amine ligands by thermolysis with Co and Cr.207 9-Hg Derivatives of C2B10H12 have been the subject of recent studies since such species are useful synthetic reagents because of the relative weakness of the B-Hg bond.Thus 9-Hg-( 1,2-C2B10H1 1)2 has been synthesized208 by mercuration of 9-1, (02CCF3)2Tl-1,2-C2BloH1and it is reported that thermolysis of 9-Hg-( 1,2- C2BIoHll),or 9-Hg-( 1,7-C2BI0Hll) cleaves the Hg-B bond to give the appropriate carbaborane B,B’-bis( carbaboranyl) and various oligocarbab~ranes.~~~ Mercur-ation of carbaboranes also affords an additional n.m.r.-active nucleus.210 Lithium derivatives of closo-carbaboranes are also of synthetic utility via classic coupling reactions eliminating LiX(X = halide). Thus 1-R-2-Li-C2BloHlo (R= Ph and I,7-Li2-C2B,,Hlo react with ( T-CIP~)C~(CO)~ or Me) 1,2-Li2-C2BIOH10 to yield the appropriate ( q-carbaboranylbenzene)Cr(CO) complexes,21 and carboranyl lanthanide complexes of several different stoicheiometries have been similarly prepared2 using lanthanide halides ; from certain of these trimethylsilylcar- baboranes and carbaboranyl ketones may be further derived.213 Alternatively car- baboranyl lanthanides are afforded by treatment of mercury carbaboranes with lanthanide metal/ Hg 206 Yu.L. Gaft Yu. A. Ustynyuk A. A. Borisenko and N. T. Kuznetsov Zh. Neorg. Khim. 1983,28 2234. 207 Yu. N. Shevchenko N. I. Yashina K. B. Yatsimirskii R. A. Svitsyn and N. V. Egorova Zh. Neorg. Khim. 1983 28 391. 208 V. I. Bregadze A. Ya. Usyatinskii and N.N. Godovikov Izu. Akad. Nauk SSSR Ser. Khim. 1983,1903. 209 L. I. Zakharkin and 1. V. Pisareva Izv. Akad. Nauk SSSR Ser. Khim. 1983 1158. 210 Yu. K. Grishin V. A. Roznyatovskii Yu. A. Ustynyuk V. Ts. Kampel and V. I. Bregadze Vesrn. Mosk. Univ. Ser. 2 Khim. 1982 23 488. 21 I L. I Zakharkin and G. G. Zhigareva Zh. Obshch. Khim. 1983 53 953. 212 V. I. Bregadze N. A. Koval’chuk N. N. Godovikov G. 2. Suleimanov and I. P. Beletskaya J. Organornerd. Chem. 1983 241 C13. 213 G. Z. Suleimanov V. I. Bregadze N. A. Koval’chuk Kh. S. Khalilov and I. P. Beletskaya J. Organomefal. Chem. 1983 255 C5. 214 G. 2.Suleimanov V. I. Bregadze N. A. Koval’chuk N. N. Godovikov and I. P. Beletskaya Dokl. Akad. Nauk SSSR 1983 270 343.

ISSN:0260-1818    

DOI:10.1039/IC9838000019

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

4 Al Ga In TI By S. M. GRIMES Department of Chemistry The City University Northampton Square London EC1 V OHB In this chapter the developments in the chemistry of Al Ga In,and T1 which have appeared in the literature over the past year are reviewed. Emphasis this year will be placed largely on the developments in the inorganic rather than organometallic field. A general review of the chemistry of these elements has been published.' 1 Aluminium A study of A1 foils for electrolytic capacitors has been made using thermogravimetry along with scanning electron microscopy X-ray diffraction and surface area tech- niques.2 The heat developing at the oxide-A1 interface during anodizing in H2S04 has also been mea~ured.~ The temperature of the A1 anode is found to increase linearly with the current density.The effects of concentration and temperature of the electrolyte and the anodizing voltage on the heat developed in A1 have been examined. The allylation of aldehydes and ketones by various allylic bromides in the presence of water using metallic A1 has been shown to be successful.4 Two papers by Antoniu et al. are ~oncerned'.~ with the reduction of Cr"' to Cr"' by metallic Al in an alkaline medium. In the first paper the rate constants and activation energies for the solution of A1 and the reduction of Cr have been ~alculated.~ A mathematical model which has been developed to describe the reduction is the subject of the second paper.6 It has been reported' that the reaction of AlH3 with CaH or of NaAlH with CaC12 in thf gives Ca(A1H4),.4thf which crystallizes in a monoclinic lattice with thf molecules co-ordinated to the calcium atom.The i.r. spectrum of aluminium tris(fluorosulphate) prepared by reaction of Al(O,CCF,) and HS03F has been recorded* and indicates a polymeric structure containing bridging bidentate ' G. Davidson Coord. Chem. Rev. 1983 49 117. J. Komives S. Gal K. Tomor and G. Kovacs J. Therm. Anal. 1983 27 315. R. M.Salen and A. A. El Hosary J. Therm. Anal. 1983 26 263. J. Nokami J. Otera T. Sudo and R. Okawara Organometallics 1983 2 191. N. K. Antoniu A. M. Egorov N. N. Sevryukov and G. E. Ermolina Russ. J. Inorg. Chem. 1983,28,69. N. K. Antoniu N. N. Sevryukov G. E. Ermolina T. V. Yanchevskaya and A. G. Pogorelov Russ. J. Inorg.Chem. 1983 28 209. B. M. Bulychev V. K. Bel'skii A. V. Golubeva P. A. Storozhenko and V. B. Polyakova Russ. J. Inorg. Chem. 1983 28 639. S. Singh and R. D. Verma Polyhedron 1983 2 1209. 61 S. M. Grimes fluorosulphate groups giving hexa-co-ordination around aluminium. Co-ordination compounds of A1(S03F) with pyridine and bipyridyl have also been obtained. A radiochemical investigation of YbCl3-(A1Cl3) complexes in the gas phase using tracer 169Yb,in the temperature range from 500 K to 1000 K was reported' and the thermodynamic data of the complexes YbAlC16 YbA12C19 YbA13Cl12 and YbA1,ClIS formed in this temperature range determined. The nature of the ionic species formed when AlCl or A1(C104) is dissolved in anhydrous methanol has been investigated using 'H 27Al and n.m.r.spectroscopy." The principal species in AlCl solution is [A1Cl2(MeOH),]+ whilst solutions of Al(C104)3 contain the hexasolvate which exhibits a broad 27Al line presumed to be due to interaction between the anion and the hexasolvated cation. Addition of water to AlCl solutions alters the spectra and these changes are discussed. Mass spectrometry" has been used to study the composition of the volatile hydrolysis products of AlCl,. Thirteen ions of aluminium oxide and hydroxide chlorides have been identified and frag- mentation schemes for the ions of hydrolysed A1C13 have been proposed. Carbon monoxide absorbents composed of aluminium copper(1) chloride and various aro- matic solvents have been prepared and the dependence of their absorbing capacities on the electronic and steric properties of the aromatic solvents determined.I2 The 13C chemical shifts and 27Al line widths for various compositions of AlC1,- dialkylimidazolium chloride molten s-alts show' the effect of the presence of the anionic species AlCl and C1- up to 0.5 mole fraction of AlCl and of the anionic species AlCl and Al2Cl in the AlCl mole fraction range 0.5-0.66.Temperature-dependent 27Al n.m.r. results show chemical exchange between chloroaluminate anions in the aluminium chloride rich molten salts. As a follow-up to their study of solutions of chlorine in some alkali chloride melts the authors14 have reported analogous data in chloroaluminate melts of AlCl,-MCl (M = Na or Cs). From a solution of AgCl/AICl a polycrystalline material of formula Ag2[Al4Cll0O2] has been isolated." The structure consists of [A14Cllo02]2- ions with the Ag+ ions co-ordinated by five chlorines in a distorted trigonal-bipyramidal arrangement.The extended structure is a three-dimensional polymer. An optical determination of carboxylate ions such as citrate oxalate and lactate utilising flocculation of Al(OH) has been carried out.16 The authors have observed that as the size of the carboxylate ion increases so too does its masking effect towards A13+ which results in a decrease in the flocculation of Al(OH),. Three papers by Ohman and Sj~bergl'-'~ have appeared reporting equilibrium and structural studies on Al"' complexes. Redox hydrolysis and complexation equilibria in the G.Steidl F. Dienstbach and K. Bachmann Polyhedron 1983 2 727. lo J. W. Akitt R. H. Duncan and C. Setchell J. Chem. SOC.,Dalton Trans. 1983 2639. " L. I. Virin,V. N. Galyashin N. M. Kuz'min V.G. Lambrev 1. Yu.Popova I. Ya. Sabaev A. I. Chemyak and A. V. Shaposhnikov Russ. J. Inorg. Chem. 1983 28 782. I2 H. Hirai M. Nakamura and M. Komiyama Buff. Chern. SOC.Jpn. 1983 56 2519. l3 J. S. Wilkes J. S. Frye and G. Reynolds Inorg. Chern. 1983 22 3870. l4 0. Waernes and T. Ostvold Acta Chem. Scand. 1983 A37 293. l5 D. Jentsch P. G. Jones E. Schawrzmann and G. M. Sheldrick Acta Crystaffogr.,1983 C39 1173. l6 M. Muto and Y. Yamahachi Buff. Chem. SOC.Jpn. 1983 56 635. L. 0. Ohman S. Sjoberg and N. Ingri Acta Chem. Scand. 1983 A37 561. I* L. 0.Ohman and S. Sjoberg J.Chern. SOC. Dalton Trans. 1983 2513. l9 L. Ohman and S. Sjoberg Pol-vhedron 1983 2 1329. Al Ga In il 63 systems A13+ and 1,2-naphthoquinone-4-sulphonate,and A13+ and 1,2-dihydroxy- naphthalene-4-sulphonate-OH have been studied in 0.6-M Na(C1) medium at 25 *C." In the former system no stable complexes were found whilst in the latter complexes of the type AILo Al(0H)L- AIL:- Al(OH)L;- and AIL;- were formed. In the second paper18 complexation in the A13+-H3GOH- system (H3L = citric acid) has been studied with measurements being performed as potentiometric titrations in 0.6-M Na(C1) at 25 "C. Mononuclear and trinuclear Al"' citrates are formed uiz. [Al(HL)]+ [AIL] [A1L213- and [A13(OH)4L3]4-. Equilibrium constants including acidity constants of H3L have been obtained.Their final paper'' deals with a potentiometric study of Al"' pyrocatecholates and Al"' hydropyrocatecholates in 0.6-M Na(C1). Again all data can be explained with a main series of complexes uiz. AlL' AlL, AIL:- and two minor species Al(0H)L;- and A13(OH)3L3 being formed. Isotherms for the sorption of the ions CO',- HCO; CrOi- and A10 by AV-I7 and EDE-1OP resins in the Br-form have been studied.20 The static capacities and ion exchange constants of AV-17 and EDE-1OP resins in the Br-form for these ions indicate that EDE-1OP anion exchange resin in the Br-form is more suitable for purifying NaBr solutions. Lithium hydroxocarbonatoaluminate has been synthe- sized2' by treating lithium hydroxoaluminate with C02 when two moles of H20 are liberated per mole of absorbed C02.For the samples Li2O.2Al2O3-O. the parameters of 1C02. 10.5H20 and Li20.2A1,O3.O.9CO2.8.8H20 the monoclinic unit cells have been determined and their i.r. and thermal analysis curves recorded. To probe the environment of A1 atoms in non-crystalline solids such as A1203-Si02 gels soda glass and mullite precursors a recently developed technique based on magic-angle spinning n.m.r. (27Al-m.a.s.-n.m.r.) has been used.22 The crystal structure of Al( N03),9D20was determined23 by three-dimensional neutron diffraction data collected at 295 K. The asymmetric unit contains Al(D20)3,+ octahedra NO ions and three D20molecules which are not co-ordinated to A13+ ions. All nine water molecules in the formula unit are crystallographically indepen- dent and the 19 hydrogen bonds give O..-O distances in the range 2.650(2)-3.054(2)A.The hydrogen bonds donated by the D20 molecules that are co-ordinated to A13+ ions are shorter than the other hydrogen bonds. Karlik et aZ.24 have demonstrated the ability of 27Al n.m.r. to identify complexes generated by three chelating ligands namely citrate lactate and EDTA in aqueous solution at 10 mM aluminium concentration. pH-Stable complexes have been observed in a unique chemical shift position for each ligand. Substitution equilibria as a function of increasing pH have been observed for those complexes in which the ligand (citrate and lactate) displaces waters of hydration and hydroxides displace the ligands. The thermal transformation of anhydrous alumina obtained by the decomposition of the lactate citrate and tartrate of aluminium has been examined25 by thermal analysis (TG and DTA) i.r.and X-ray diffraction studies. It is found that under an atmosphere of air the thermal decomposition of aluminium hydroxycarboxylates to anhydrous amorphous alumina which transforms to a-alumina uia y 6- and 20 N. K. Antoniu N. N. Sevryukov and A. M. Egorov Russ. J. Inorg. Chem. 1983 28 94. 2' E. T. Devyatkina N. P. Kotsupalo N. P. Tomilov and A. S. Berger Russ,J. Inorg. Chem. 1983,28,801. 22 J. M. Thomas J. Klinowski P. A. Wright and R. Roy Angew. Chem. In?. Ed. Engl. 1983 22 614. 23 K. Hermansson Ada Crystallogr. 1983 C39 925. 24 S. J. Karlik E. Tarien G. A. Elgavish and G. L. Eichhorn Inorg.Chem. 1983 22 525. 25 T. Sato S. Ikoma and F. Ozawa J. Chem. Tech. Biotech. 1983 33A 415. S. M. Grimes r T 11111111 --II I II Ill1 I 141 1 1 1 1 1i 0 200 400 600 800 1000 0 200 400 600800 1000 Temperature ("C Figure 1 TGA and DTA curves of aluminium hydroxycarboxylutes under atmospheres of uir(a) and nitrogen (b) L lactate; C citrute; T tartrate (Reproduced by permission from J. Chem. Tech. Biotechnol. 1983 33A 415) @aluminas proceeds as follows for Al[CH,CH(OH)COO], the decompositions of skeleton and the combustion of its decomposition products; for A1[CH2C(OH)CH2(C0O),] and A12[(CH(OH)C00)2]3 dehydroxylation decompo- sition of skeleton and the combustion of its decomposition products. Figure 1 gives examples of some of the thermal traces obtained for these decompositions.A study of the kinetics of the reversible complexation of Al"' with some substituted (salicy- 1ato)penta-amminecobalt(r1I)ions has been described.26 It is reported2' that Et Bun and Bu' aluminium dichlorides undergo 1,6-addition to a conjugated bond system O=C-C=C-C=O of para-quinones. Methyl- aluminium dichloride is inactive in this addition and triethylaluminium gives low yields. The reactivities of the quinones are observed to vary with their electron affinities and the highest yields of 1,6-addition are obtained in reactions of chlorine 26 A. C. Dash Inorg. Chem. 1983 22 837. 27 Z. Florjancyk and E. Szymanska-Zachara J. Orgnnomer. Chem. 1983 259 127. Al Ga In T1 Table 1 27Al N.m.r.parameters of organoaluminium compounds Compound 8(2'~i) C.N. i-Pr,Al 256 3 i-Bu,Al 276 3 t-Bu,Al 255 3 Me,A1 153 4 Et3AI I54 4 n-Bu,Al 152 4 Et2AlH 157 4 Et2AICI 167 4 Et2AlNEt2 160 4 Et2A10Me 146 4 Et AlOEt 151 4 Et,AlO(CH&OEt 151 4 Me,AlO(CH,),OMe 121 5 Et2A10(CH2)20Me 121 5 Et,AlO(CH,)2OEt 126 5 Et2AlO(CH2)2NEt2 112 5 (acac) A1 0 6 derivatives of 1,Cbenzoquinone. The results have been discussed in terms of a radical mechanism involving a homolytic cleavage of the AI-C bond. The reaction of (C6H5)3P=CH2 with A1C13 in the mole ratio of 2 :1 3 :1 or 5 :1 is said2* to yield two new compounds viz. di-~-chloro-bis[bis(methylenetriphenylphosphorane)-aluminium]tetrachloride from 2 1 and p-chloro-bis[tris(methylenetriphenylphos-phorane)-aluminium]pentachloride from 3 :1 or 5 :1.These dimers bridged by chloride anions are thermally stable. Benn et al.29 have shown by the use of 27Al n.m.r. spectroscopy that in general a simple correlation exists between co-ordin- ation number and S(27Al) in organoaluminium compounds (Table 1). In addition the authors have confirmed the pentaco-ordination of the A1 atoms in Me2A10(CH2)20Me. The co-ordination geometry can be described as a distorted trigonal bipyramid in which two methyl groups and an oxygen atom are located in the equatorial plane. The properties of A'",Fe"' and Cr"' complexes of methylthy-mol blue semimethylthymol blue xylerol orange and semixylerol orange have been e~amined.~'In particular the influence of electron donating substituents on the stability rate of formation and the positions of the absorption bands of the tervalent metal complexonates has been determined.The reaction of an anion of diphenylphosphine oxide prepared by the action of sodium dihydrobis(2-methoxyethanolato)aluminateon the oxide with various men- thy1 or neomenthyl halides and sulphonates were studied3' to clarify the stereochemistry of the substitution. The reaction gave neomenthyl- and methyl- diphenylphosphine oxide in ratios from 1OO:O to 0 100. The unusual anion 28 Y. Yamamoto Bull. Chem. SOC.Jpn. 1983 56 1772. 29 R. Benn A. Rufinska H. Lemkuhl E. Janssen and C. Kruger Angew. Chem. Znt. Ed. Engl. 1983,22 779. 30 N. F. Kosenko Russ. J. Inorg. Chem 1983 68 71.31 M. Yamashita Y. Soeda N. Suzuki M. Yamada K. Tsunekawa T. Oshikawa and S. Inokawa Bull. Chem. SOC.Jpn. 1983 56 1871. 66 S. M. Grimes [A1706Me,6]- has been en~ountered~~ in the decomposition pathways of two (high oxygen-content) organoaluminium compounds K[Al,Me602] and Cs2[A12Me60]. Crystalline materials of triclinic K[AI7O6Me,,].C6H6 and cubic Cs[A1,O6MeI6]. 3C,H,Me have been isolated. The structures consist of open A1606 cages capped by the seventh A1 atom which is bonded to three alternate 0 atoms in the cage. The six A1 atoms are bonded to terminal Me groups each while the unique A1 is bonded to only one Me group. A new method has been developed33 for the determination of solvent donicity towards the Na ion that avoids solvent-solvent interactions.Using the system NaAlEt,-benzene-donor the response of the quadrupole relaxation to anion symmetry as a function of the donor Na' ratio is monitored by both 27Al line widths and methylene H absorptions. The crystal structure of y-A1B12 has been reinvestigated by single crystal X-ray diffractometry and the nature of the A1 distribution in the boron framework examined.34 The aluminium atoms are said to be distributed in the boron framework according to a simple rule as in the crystals of the a-AIBI2 structure type. The structure of Sr,AI, together with those of Ba,Ga and Sr,Ga has been determined.35 The three compounds are isotypic and the structure of SrBAl7 is characterized by the presence of isolated tetrahedral and triangular clusters of A1 atoms included in cages of 13 Sr atoms.Three types of precipitates are observed in TiAl alloys containing from 50 to 58 atomO/~AI.~~ Two types were found in the alloys Ti46Als4 and Ti42A158 both of which have ordered superstructures of an f.c.c. lattice. The third type of precipitates is present in the alloys Ti46A154 and Ti50A150. The proposed structure corresponds to the compound Ti2A1 and can be described as a stacking of six close-packed planes of type AB'ABA'B or AB'CBC'B in which the planes A are pure Ti planes and the planes A' pure Al planes. The interaction of BeF2 and AlF at temperatures of 400 500,600,700 and 800 "C and AlF3 concentrations of 0-75 mole% has been in~estigated.~~" Preliminary results on the equilibrium diagram of the AlF,-BeF2 system have been presented.BaA1,-type derivative structures can be classified according to the type of co-ordination polyhedron around the transition metal which can be a tetrahedron or a square ~yramid.~' The charge-density distribution in LiA1BI4 has been studied3 by X-ray diffractometry to elucidate the role of the metal atoms in stabilizing the structure. The results seem to suggest there is a charge transfer from the metals to the electron-deficient boron framework. Another paper contains a report on the charge-density distribution in crystals of CUA~O~.~~ The study showed that the deformation of the electron-density distribution can be well explained by assuming d-s hybridization with linear combination of the 3dz2and 4sorbitals for the valence 32 J.L. Atwood D. C. Hrnar R. D. Priester and R. D. Rogers Organornetallics 1983 2 985. 33 M. C. Day J. H. Medley and N. Ahmad Can. J. Chern. 1983 61 1719. 34 I. Higashi J. Solid Srare Chern. 1983 47 333. 35 M. L. Fornasini Acta Crystallogr. 1983 C39 943. 36 A. Loiseau and A. Losalmonie Acta Crystallogr. 1983 B39 580. 360 B. S. Zakharova and L. P. Reshetnikova Russ. J. Inorg. Chern. 1983 28 133. 37 E. Parthe B. Chabot H. F. Braun and N. Engel Acta Crystallogr. 1983 B39 588. 38 T. Ito and I. Higashi Acta Crystallogr. 1983 B39 239. 39 T. Ishiguro N. Ishizawa N. Mizutani M. Kato K. Tanaka and F. Marumo Acta Crystallogr. 1983 839 564. Al Ga In 77 67 electrons of the Cu+ ion. The solubility of A1 and Fe in LaNi, up to compositions of x = 1.5 and 1.2 respectively and the formation of continuous solid-solutions between LaNi and LaCuS have been confirmed4* by X-ray diffraction studies of the alloys of the LaNi,-,T systems where T is Al Cr Fe or Cu.The replacement of Ni in LaNi by Al Cr Fe or Cu is found to increase the stability of the corresponding hydride phases and reduce the absorption capacity of the intermetallic compounds. Phase formation in A1203-M203 systems (M = In V or Ti) has been considered as a function of temperature;l with the aid of space-energy concepts. In another paper42 the equilibrium diagram of the A120,-V205 system constructed using DTA and X-ray diffraction techniques has been presented. The temperature for the peritectic fusion of A1VO4 is found to depend on the partial pressure of oxygen in the synthesis of the system.Two papers by Fotiev et a143*44describe the use of thermodynamic and X-ray diffraction analyses to triangulate A1203-Si02-V205 Al,O,-K20-V205 and Al2O3-Na20-V2O5 and to tetrahedrate A1203-K20-Si02- V205 and A1203-Na20-Si02-V205 systems. Another study by Fotiev and Surat4 used the same. methods to triangulate systems in the subsolidus region containing orthovanadates FeVO, CrV04 AlV04 and metavanadates KVO and to tetrahedrate the FeV0,-CrV0,-AlV0,-KVO quaternary system. Three new pyrovanadates of general formula KMV207 (M = Fe Cr or Al) are formed. Results of investigations of two ternary systems uiz. A1203-B203-M20 (M = Li or Na) have been reported by Abdullaev et al.46747From the Li-~ystem~~ five new borates are formed ;2Li20.A1203.2B203; Li20.A1203.B203 and 3Li2O.Al2O3.2B2O3 ; Li20-A1203-2B203 Li20.2Al2O3-2B2O3 with melting points 730 785 760 850 and 775 "C respectively.Three new borates are formed in the Na-~ystem:~~ 5Na20.B20,; Na20.Al,03.B20 and Na20.A1,O3-2B2O3 with melting points of 750 1010 and 1025 "C respectively. The preparation structure and magnetic properties of isostructural La3MA1S7 and La3MFeS7 (M = Mg Mn Fe Co Ni or Zn) quaternary metal sulphides have been rep~rted.~' The structure of a new magnesium aluminium zirconium oxide Mg5+xA12,4-xZr1.7+0,25x012 with -0.4 5 x 5 0.4 has been determined.49 Five papers appearing in the literature are concerned with Al-containing zeolites and related minerals.The structure of basic sodalite a member of the zeolite family has been determined.50 The 1 1 alumino-silicate framework is completely ordered whereas both the 0 of the hydroxy-group and the water molecule are disordered about the body diagonal of the cubic cell. A structure refinement on mathiasite has been carried out.5' It is isostructural with the crich- tonite-group minerals AM2,03* and is characterized by dominant potassium in the 40 K. N. Semenenko L. A. Petrova and V. V. Burnasheva Russ. J. Inorg. Chem. 1983 28 107. 41 G. A. Korablev V. T. Ivashinnikov A. A. Fotiev V. E. Gladkov and A. S. Zubov Russ. J. Inorg. Chem. 1983 28 881. 42 S. M. Cheshnitskii A. A. Fotiev and L. L. Surat Russ. J. Inorg. Chem. 1983 28 758.43 A. A. Fotiev L. L. Surat and I. P. Kolenko Russ. J. Inorg. Chem. 1983 28 119. 44 A. A. Fotiev B. V. Slobodin L. L. Surat and T. P. Sirina Russ. J. Inorg. Chem. 1983 28 588. 45 L. L. Surat and A. A. Fotiev Russ. J. Inorg. Chem. 1983 28 1059. 46 G. K. Abdullaev P. F. Rza-Zade and Kh. S. Mamedov Russ. J. Inorg. Chem. 1983 28 428. 47 G. K. Abdullaev P. F. Rza-Zade and Kh. S. Mamedov Russ. J. Inorg. Chem. 1983 28 11 5. 48 K. S. Nanjundaswamy and J. Gopalakrishnan J. Solid State Chem. 1983 49 51. 49 P. Tassot G. Konig F. Liebau and F. Seifert J. Appl. Cryst. 1983 16 649. 50 I. Hassan and H. D. Grundy Acta Crystaflogr. 1983 C39 3. 5' B. M. Gatehouse 1. E. Grey and J. R. Smyth Acta Crystallogr. 1983 C39,421. 68 S. M. Grimes large-cation A site.Partial disorder in the M-cation sublattice is interpreted as due to the partial occupation of a second anion site by large cations. The structure of dehydrated zeolite 3A (Si/Al = 1 .O1) has been determined by neutron profile refine- ment.52 27Al N.m.r. has been showns3 to be a valuable tool in probing the co- ordination quantity and location of A1 atoms in chemically treated zeolites. Heats of adsorption of pyridine and ammonia were respectively measureds4 on Al-deficient H-Y zeolites using a microcalorimeter at 473 K. The calorimetrically determined acidity was discussed in relation to the positional difference between 3640 and 3550 cm-' OH acidic sites and compared with the catalytic activity. The reaction of LiA1H4 with C02 or NaHCO at elevated temperatures has been inve~tigated.~~ From their study the authors concluded that methane and ethene the primary products of each reaction are probably the explosive reaction products formed when C02 fire extinguishers are used on LiAlH4 fires.The catalytic cracking of slack wax with molten mixtures of A1C13 and AlBr3 as catalyst was investigateds6 in an atmospheric semi-batch reactor at low temperatures of 100-160 "C. The effect of parameters such as reaction temperature HCl catalyst composition and concentra- tion on the cracking rate and product distribution has also been investigated. Two papers report the use of AlP04 catalysts. One deals with the application for the first time of the Hammett equation in the esterification of substituted benzoic acids (m-MeO p-MeO m-Me p-Me H m-NO, m-C1 and m-Br) catalysed by AlP04 of the F type.57 The other reportss8 an investigation of the skeletal isomerization of cyclohexene in a microcatalytic pulse-reactor using several A1 orthophosphates (Al/P = 1) as catalysts.The kinetics of leaching of Raney Ni-A1 alloy (Ni 50% w/w) with alkali has been studied59 in an agitated reactor by measuring the rate of H2 evolved in the leaching process at constant alkali concentrations. The effects of process parameters such as temperature type and concentration of alkali particle size of the alloy and stirring speed on the leaching process have also been investigated. Finally a method for the interpretation of the Warren-Averbach mean-squared strains and its applica- tion to recovery in aluminium has been presented.,' 2 Gallium The isolation and crystal structure of [(c,H~)~G~.G~C~,],.~C,H, has been reported6' and is the first structurally characterized benzene complex of a univalent main-group metal.It consists of cyclic centrosymmetrical [(C~H,),G~'G~''~CI,]~ units and iso- lated benzene molecules. 52 J. M. Adarns and D. A. Haselden J. Solid State Chem. 1983 47 123. 53 J. Klinowski J. M. Thomas C. A. Fyfe G. C. Gobbi and J. S. Hartrnan Inorg. Chem. 1983 22 63. 54 Y. Mitani K. Tsutsurni and H. Takahashi Bull. Chem. Soc. Jpn. 1983 56 1921. 55 B. T. Thompson T. N. Gallaher and T. C. De Vere Polyhedron 1983 2 619. 56 Y. Ohtsuka K. Oizurni and Y. Tamai Bull. Chem. Soc. Jpn. 1983 56 2716.57 J. V. Sinisterra J. M. Marinas and A. Llobera Can. J. Chem. 1983 61 230. 58 J. M. Carnpelo A. Garcia J. M. Gutierrez D. Luna and J. M. Marinas Can. J. Chem. 1983 61 2567. 59 V. R. Choudhary and S. K. Chaudhari J. Chem. Tech. Biotech. 1983 33A 339. 60 M. J. Turunen Th.De Keuser R. Delhez and N. M. Van der Pers J. Appl. Crystallogr. 1983 16 176. 6' H. Schrnidbaur U. Thewalt and T. Zafiropoulos Organomerallics 1983 2 1550. 62 P. G. Nelson and R. V. Pearse J. Chem. Soc. Dalton Trans. 1983 1977. 63 R. W. Berg and N. J. Bjerrurn Polyhedron 1983 2 179. Al Ga In TI 69 The standard enthalpies of formation at 25 "C have been determined by solution calorimetry6 for a number of potassium hexafluorometallates(Ir1) of the elements from Sc to Ga.The value obtained for K,GaF6 was -300 1 kJ mol-'. The reaction between sulphur and gallium in chlorobasic melts at ca. 500 "C has been studied6 by visual observation and Raman spectroscopy. The results suggest the formation of charged long chains (-GaCl,-S-GaC1,-S-) in these melts and the presence of the radical anion S under certain conditions. Absorption spectroscopy has been to study the formation of gaseous complexes between NdC1 and GaC1 in the temperature range 600-1000 K and at total pressures ranging from 5 to 20 atm. Thermodynamic model calculations indicate a stepwise build-up of the gas com- plexes with the formation of the molecules NdGaCI, NdGa2C19 NdGa3Cl12 and NdGaCl,,. The thermal expansion tensor of P-Ga,03 was determined65 from low-temperature X-ray diffraction.At T = 250 K the principal directions of the tensor are close to the mean directions associated with the various chemical bonds of the monoclinic structure. Alkali metal gallates have been synthesized and their homogeneity confir- med by X-ray diffraction.66 The thermal properties of the compounds Ga203 LiGaO, NaGa02 KGa02 RbGaO, and CsGaO, have been investigated by differ- ential thermogravimetry. All gallates melt congruently except the Cs derivative which melts incongruently. Another paper reports6' on the relationship of crystallographic polarity to piezoelectric pyroelectric and chemical etching effects in Li2Ge03 and LiGaO single crystals. The crystal structure of GaLa30S28 has been determined. The La atoms are in eight- and nine-fold co-ordinations and the Ga atom has a tetrahedral environment.The structure contains rings of 0-La-0-La which form chains parallel to the b direction. Ghemard et a169have identified Ga2Se to be a superstructure of the basic distorted sphalerite-type. Ordering of metal vacancies involves two different Se-atoms surrounding infinite chains of vacancies running in the b-direction and the particular stacking sequence abca'b'c' derived from ABC close packing for Ga atoms. The reactions of (C6H5),P=CH2 with GaC1 in a 2 1 3 1 or 5 1 mole ratio yield2* two new compounds viz. di-p-chloro-bis[bis(methylenetriphenylphos-phorane)gallium]tetrachloride from the 2 :1 ratio and p-chloro-bis[tris(methyl-enetriphenylphosphorane)gallium]pentachloride from the 3 1 or 5 1 ratio.Elec- trolysis of dimethylmagnesium in thf with a gallium anode is reported7' to yield the adduct GaMe,-thf directly. The trialkylamine and trialkylphosphine adducts GaMe3-L (L = NEt, PMe, or PEt,) are obtained by direct addition of an excess of L to GaMe,.thf. Free GaMe is obtained by reaction of Me1 with a Mg-Ga alloy in an ether solvent. The nature of the reactions that occur between Ga(CH,SiMe,) and In(CH,SiMe,) with alkali metal hydrides has been reinvesti- 64 T. Foosnaes and H. A. Oye Inorg. Chem. 1983 22 3873. 65 D. Dahy and J. R. Gavarri J. Solid Slate Chem. 1983 49 107. 66 A. A. Zakharov and I. S. Shaplygin Russ. J. Znorg. Chem. 1983 28 59. 67 A. S. Bhalla L. L. Tongson and R. E. Newnham J. Appl.Crystallogr. 1983 16,138. 68 S. Jaulmes A. Mazurier and M. Guittard AC~Q Crystallogr. 1983 C39 1594. 69 G. Ghemard S. Jaulmes J. Etienne and J. Flahaut Acta Crystallogr. 1983 C39,968. 7o A. C. Jones D. J. Cole-Hamilton A. K. Holliday and M. M. Ahmad J. Chem. Soc. Dalton Trans. 1983 1047. S. M. Grimes Figure 2 The arrangement of gadolinium-oxygen dodecehedra gallium-oxygen octahedra and gallium-oxygen tetrahedra in Gd,Ga,O garnet (Reproduced by permission from Acta Chem. Scand. 1983 A37 203) gated.71 Contrary to previous reports KGa(CH2SiMe3)3H and KIn(CH,SiMe,),H were isolated and their crystal structures determined. The gallium hydride derivative is thermally stable under the normal synthetic conditions and does not convert into KGa(CH2SiMe3) and SiMe as originally proposed.Extraction of Ga"' with decanoic acid in several solvents was carried at 25 "C and at an aqueous ionic strength of 0.1 mol dm- (NaClO,). The organic solvents used were toluene chlorobenzene 1,2-dichloroethane and octan- 1-01. It was found that the less polar the solvent the more extensive was the polymerization of the extracted decanoates. The formation of Ga lanthanide and vanadium complexes with catechol violet and cetylpyridinium bromide has been in~estigated~~ spectrophotometrically. The influence of the complex-forming ion on the principal physiochemical characteristics of the complexes has been examined. The component ratio in the complexes has been found the mechanism of the reaction established and the stability constants of the complexes calculated.Belin and Ling74 have surveyed the preparation and structural properties of the intermetallic phases of gallium and alkali melts. Unlike the already known phases of Ga with Li or Na the structures of the recently discovered phases Li3GaI4 Na,,Ga,, KGa, K3Ga13 RbGa, RbGa, and CsGa are characterized by stackings of co-ordinated gallium polyhedra such as icosahedra octadecahedra dodecahedra and undecahedra. In these phases the alkali metals stabilize the gallium framework by giving their valence electrons. The structures are interpreted according to Wade's electron counting procedure. The two compounds Ba8Ga7 and Sr8Ga7 are isotypic with Sr8A1735 and their structures are characterized by the presence of isolated tetrahedral and triangular clusters of Ga atoms in cages of 16 alkaline earth atoms.The structural parameters for Gd3Ga5012 garnets (Figure 2) have been refined with single crystal diff ractometer data.75 High quality crystals were obtained when 7' R. B. Hallock 0.T. Beachley Y.-J. Li W. M. Sanders M. R. Churchill W. E. Hunter and J. L. Atwood Inorg. Chem. 1983 22 3683. 72 H. Yamada S. Imai and E. Takeuchi Bull. Chem. SOC.Jpn. 1983 56 1401. 73 L. I. Ganago L. A. Alinovskaya L. N. Bukhteev and N. N. Ishchenko Rum. J. Znorg. Chen 1983 28 52. 74 C. Belin and R. G. Ling J. Solid State Chem. 1983 48 40 75 J. Sasvari and P. E. Werner Acta Chem. Scand. 1983 A37 203. Al Ga In TI 71 prepared in the presence of small amounts of CaO.From the diffraction data however no significant differences between calcium and non-calcium induced crys- tals were detectable. The structure76 of Ga,Sn2S is essentially built up from two kinds of sheets parallel to the (100) plane alternately a sheet of [GaS,] tetrahedra and a sheet of [Sn2Sll],,. The [Gas,] tetrahedra are linked in groups of two with their opposite edges shared. The equilibrium diagrams of the Ga2S3-PbS and Ga2S3Pb sections have been con~tructed'~ by physiochemical methods. The Ga2S3- PbS section is quasibinary. The ternary compound PbGazS4 which has a homogeneity region of 1.5 mole% is formed at the 1 1 molecular ratio of the components. Another paper by Rustamov ef reports that the magnetic properties of solidified melts of the FeSe-Ga2Se3 system have been studied.All the intermediate solidified melts are paramagnetic in the temperature range 80-300 K and the temperature depen- dence of the magnetic susceptibility obeys the Curie-Weiss law. The structures of Pb3GeGa10020 and Ba3SnFe,,02 have been determined79 and are found to be isostructural with each other and with Pb3GeAl,0020 and Ba3TiAl10020. The structure consists of a framework of six-membered rings of tetrahedra which form a ribbed plane. These planes are connected by a string of octahedra and by an M2+ ion in octahedral co-ordination. The other M2+ ion is situated inside the rib of the ribbed plane and has irregular seven or eight co- ordination. Finally it is reported" that a series of solid solutions in the system (GaxInl-x)2(SexTel-x)3,1 2 x 5 0 have been prepared by direct synthesis from a-Ga2Se3 and a-In,Te3.The samples were examined at room temperature by X-ray diffraction. In the whole range of concentrations cubic phases of defect zinc-blende types are present. 3 Indium An X-ray study of a mixed indium chalcogenide In-,,,,X3 (X = S Se or Te) has been carried out.' The semiconductor crystallizes in trigonal space group at room temperature. The unit cell content was found to be 1n'1n"'(0ct)~1n"'(tetr),~X~5 with an apparent chalcogen ratio Se :Te of 2.22 3 (S :Se :Te = 1 :2 3 from electron microprobe analysis). The chalcogen octahedron around one type of In"' atom shares edges with six distorted In"'-X tetrahedra. The possible exchange of some In"' for In' in various indium chalcogenide compounds has been discussed.The influence of added C1- and In"' on the thermal kinetics of the reaction of InCl(so1id) with aqueous nitrate solutions has been studied.82 Direct experimental proof of the activation by the C1-ion of the heterogeneous disproportionation of InCl in these solutions has been obtained and the influence of the Ino nuclei in the InCl matrix on the kinetics of the reaction demonstrated. 76 A. Mazurier F. Thevet and S. Jaulmes Acta Crystallogr. 1983 C39 814. 77 Z. D. Melikova and P. G. Rustamov Russ.J Znorg. Chem. 1983 28 919. 78 P. G. Rustamov N. Kh. Ali-Zade P. K. Babaeva M. R. Allazov Ya. N. Sharifov and D. M. Ragimova Russ. J. Znorg. Chem. 1983 28 453. 79 M. C. Cadee G.C. Verschoor and D. J. W. Ijolo Actu Crystallogr. 1983 C39 921. 80 B. Grzeta-Plenkovic S. Popovic B. Celustka Z. Ruzic-Toros B. Sentic and D. Soldo J. Appl. Crystallogr. 1983 16 415. C. Svenson and J. Albertsson J. Solid State Chem. 1983 46,46. 82 V. A. Smirnov Russ. J. Znorg. Chem. 1983 28 772. 72 S. M. Grimes Rapid diffusion of l80 ions in indium oxide during reduction-oxidation reactions has been useds3 to explain the observation that reduced-indium oxide is one of the most efficient compounds among the reduced metal oxides for reduction of H20 CO, or NO. In their paper,66 Zakharov and Shaplygin also report the synthesis of some alkali metal indates and their homogeneity has been confirmed by X-ray diffraction. The thermal properties of Inz03 LiInO, and NaIn02 have been investi- gated by differential thermogravimetry.Bulc et uZ.84985 report the structures of three oxalate complexes of indium. The In atom of the complex [In2(C204)3(H20)4].2H2084 is co-ordinated by 0 atoms in the form of a pentagonal bipyramid. These polyhedra are linked through the oxalate groups as bridging ligands thus forming infinite chains along the (001) direction. The average In-0 bond distance is 2.234(16)A to oxalate 0 atoms and 2.157(2) A to water molecules. There are three independent water molecules in the structure. The dihydrated ammonium and sodium bis(oxalato)indates(~rr)are isomorphous.8s In NH4[In(C204),]2H20 which was refined to an R value of 0.024 the In atom is co-ordinated by eight 0 atoms from four oxalate groups as bridging ligands forming a distorted Archimedean antiprism ; four In-0 distances are 2.197(4) 8 and four are 2.351(5) A.Ammonium ions and water molecules occupy the cavities between the anions and are linked to the anions and to each other by H bonds. The crystal structure of indium(r1r) dithizonate has also been determineds6 by X-ray diffraction methods at 295 K. The asymmetric unit of the structure is the mononuclear [In(Hdz),] molecule the indium atom is five-co- ordinated as a trigonal bipyramid one ligand being unidentate and co-ordinated equatorially through the sulphur [In-S 2.468(3) A] while the other two are bidentate (N S) spanning axial and equatorial positions. The axial In-N distances are 2.372(6) and 2.334(6) 8 while the associated equatorial In-S distances are 2.477(3) and 2.467(3) A.Isolation of KIn(CH2SiMe3),H from a reaction of In(CH,SiMe,) with alkali metal hydrides has been rep~rted.~ Like KGa(CH2SiMe3)3H the indium derivative crystallizes in the monoclinic space group but unlike the Ga derivative KIn(CH2SiMe3)3H decomposes at room temperature The differences in thermal stability between the two materials is related to the ease of the dissociative reactions of the four-co-ordinate anions and their relative metal-carbon bond strengths. Reductive elimination does not appear to be an important reaction path for these organo Group 3 derivatives. The reaction of (C6H5),P=CH2 with InCI3 in the mole ratio 2 1 yields28 a new compound of di-p -chloro-bis[bis(methylenetriphenylphos-phorane)indium]tetrachloride.Phase equilibria in the BaO-1n2O3 system have been investigatedx7 over a wide temperature range (1200-1600 K) and concentration (10% Ba0-60% BaO). The compounds Ba,In,Os Ba,In206 Ba21n20S cu-Ba41n60,, a-Ba4In,Ol3 and BaIn204 are formed. The lattice parameters of all these compounds were determined and their i.r. and Raman spectra studied. The theoretical vibrational spectra of the double 83 R. Otsuka T. Yasui and A. Morikawa Bull. Chem. SOC.Jpn. 1983 56 2161. 84 N. Bulc and L. Golic Acta Crystallogr. 1983 C39 174. N. Bulc L. Golic and J. Siftar Acra Crystallogr. 1983 C39 176. 86 J. McB. Harrowfield C. Pakowatchai and A. H. White J. Chem. Soc. Dalton Trans. 1983 1109. 87 T. A. Kalinina L.N. Lykova L. M. Kovba M. G. Mel’mikova and N. V. Porotnikov Russ. J. Inorg. Chem. 1983 28 259. Al Ga In TI 73 oxides LaIn03 and YSc03 with orthorhombic perovskite-type structures have been calculateds8 by the valence force-field method using the polymeric chains approxima- tion. The variation of the force constants of the La-0 bonds in LaIn03 with the In-0 distance is given. A crystal structure determination of In~Kss has showns9 that the In atoms are in four- or six-fold co-ordination and the potassium atom is in six-fold prismatic co-ordination. Far infrared reflection spectra of hot-pressed samples of the spinels MCr2S4 (M = Mn Fe Co Zn Cd or Hg) MCr2Se4 (M = Zn Cd or Hg),and MIn2S (M = Mn Fe Co Ni Cd or Hg) have been recorded” in the range from 40 to 700cm-I.From the spectra transverse and longitudinal optical phonon frequencies optical and dielectric constants and effective charges of the compounds have been calculated. A study of the interaction between In Sb and Tl has shown” that the InSb-TI section is quasibinary and triangulating in the InSb-T1 system. The crystallization regions of InSb and of T1 and the melting point (523 K) and composition of the eutectic (88 atom%Tl) were determined. The L~I~(MoO,)~-MI~(MOO,) (M = K or Rb) quasibinary sections of the Li20-M20-In20,-Mo03 quaternary systems (M = K or Rb) have been investi- gated92 to find whether ternary molybdates containing two different alkali cations and the cation of a tervalent element could be formed but no distinct ternary phases were isolated.The crystal structure of Pb,,61n8Bi4S19 has been determined.93 The structure consists of distorted In-S octahedra and mono- and bi-capped triangular prisms of Bi-S as well as bicapped triangular prisms of Pb-S all forming chains along y. The phase diagrams of the quaternary systems MS-Cr2S3-In2S3 (M = Co Cd or Hg) were by high-temperature X-ray diffraction patterns DTA and TG measurements and far-infrared spectra. Complete series of mixed crystals are formed among the spinel-type compounds MCr2S4 MIn2S4 (M = Cd or Hg) and In&. In the sections CoCr2S,-CoIn2S and CoCr2S4-In2S3 relatively large miscibil- ity gaps exist due to the change from the normal to inverse spinel structure. A series of samples in the system CuGaxIn,-,Te2 0 d x G 1 has been synthesized and characterized by X-ray diff ra~tion.~’ All the samples have a chalcopyrite-type struc- ture the unit cell parameters a and c and the ratio c/a changing linearly with x.The series (GaxIn,-x)2(SexTel-x)3 1 x z= 0 has also been examined by X-ray diffraction.80 In the In2Te3-rich region the diffraction pattern is similar to that of the disordered phase of In2Te3. 4 Thallium The solubilities of Tl’ halides and their crystallization from aqueous solutions have been studied and the corresponding crystallization induction periods have been calculated as a function of super~aturation.~~ The results were used to develop 88 N. V. Porotnikov 0.I. Kondratov and K. I. Petrov Russ. J. Znorg. Chem. 1983 28 105. 89 D.Carre and M. P. Pardo Acta Crystallogr. 1983 C39 822. 9o H. D. Lutz G. Waschenbach G. Kliche and H. Haeusler J. Solid State Chem. 1983,48 196. ” 0. V. Sorokina S. B. Evgen’ev and I. V. Mashchenko Russ. J. Inorg. Chem 1983 28 916. 92 N. N. Smirnyagina N. M. Kozhevnikova F. P. Alekseev and M. V. Mokhosoev Russ. J. Inorg. Chem. 1983 28 892. 93 V. Kramer Acta Crystallogr. 1983 C39 1328. 94 H. D. Lutz W. W. Bertram B. Oft and H. Haeusler J. Solid State Chern. 1983 46 56. 95 B. Grzeta-Plenkovic and B. Stank J. Appl. Crystallogr. 1983 16 576. 96 F. N. Kozlov G. A. Kitaev and L. V. Zhukova Russ. J. Inorg. Chem. 1983 28 268. 74 S. M. Grimes effective methods of purifying raw materials by growth of single crystals using the Stockbarger method.The thermodynamic^^^ of dissolving TI' iodide in water and 0.5 1.0 3.0 and 4.0 M aqueous solutions of sodium perchlorate and iodide at temperatures of 278 298 and 318 K have been studied by solubility and poten- tiometric methods using a Tl(Hg) electrode. Forty-five new Tl' carboxylates have been ~ynthesized~~ and characterized by their i.r. spectra and melting points. The i.r. spectra and laser Raman spectra of crystalline Tl' formate acetate propionate and acrylate have been recorded99 and the observed vibrational wavenumbers assigned to groups of atoms. In the carboxylates studied the bond between TI' and the carboxylate group is ionic in character. Two methods (the Harowitz-Metzger and the Dharwadkar-Karkhanavala) for calibrating the apparent activation energies of different T1' oxalates have been compared.loo The activation energies from the latter equation for separate samples of T1' oxalate are consistent and the activation energy for T12C204-+T120 is -109 kJ mole-'. However results from the Harowitz-Metzger method for the decomposition of different samples of TI' oxalate obtained from different sources showed considerable variation. The mixed-ligand complex formation of o-mercaptobenzoic acid and citric acid with Cd" Pb" and Tl' in aqueous KNO solutions containing Triton X-100has been investigated'" by polarography. It was shown that only one mixed ligand MA,X is formed where i is two for Cd" and one for Tl' j is one for all complexes and A and X are the o-mercaptobenzoate and citrate ligands respectively.The structure of Tl[B304(OH)2]0.5H20 has been determinedIo2 and is shown to contain a [B304(OH)2]- unit formed by one tetrahedron and two triangles. These units are linked together to form an infinite [B304(OH)2]:- chain and between these chains linked by hydrogen bonds T1+ and H20 are localized. Another borate structure of T14[B8012(0H)4]H20 has been shown'03 to contain a unit [B8012(0H)4]4- formed by four B04 tetrahedra and four B03 triangles. The units [B7010(OH)3-OBO(OH)]4-are linked together to form an infinite chain. T1' and H20 are located between the chains. Both crystal structures of Tl~"TeOI2 and TliTeO have been determined.lo4 In both compounds the Te atom is octahedrally co- ordinated to oxygen atoms with Te-0 distances of 1.936 A for the former and 1.946 8 for the latter.In the former structure the T1"' is surrounded by seven oxygen atoms sitting at the summits of a distorted monocapped trigonal prism whilst in the latter T1' is linked to three oxygen atoms forming a distorted T103 pyramid. The crystal stuctures of three other T1' materials have been reported. In the basic thallium sulphate T12TIOH(S04)2 the TI+ ions ensure bonding between [TI"'OH(S04)2] sheets.'" The structure Tl2S7N8 consists of TI+ cations and (S3N3)-and (S,N,)-anions.Io6 Rey et al. have determinedIo7 the structure of TlSbS2 which 97 I. D. Isaev V. A. Fedorov V. P. Antonova and V. E. Mironov Russ. J. Inorg. Chern. 1983 28 751. 98 T. V. Lysyak S. L. Rusakov I. S. Kolomnikov Yu. Ya. Kharitonov Russ.J. Inorg. Chern. 1983,28,756. 99 Yu. Ya. Kharitonov I. I. Oleinik and N. A. Knyazova Russ. J. Inorg. Chem. 1983 28 477. I00 S. R. Sagi K. V. Ramana and M. S. Prasada Rao Russ. J. Inorg. Chern. 1983 27 155. 101 K. C. Gupta and K. K. Sharma Bull. Chern. SOC.Jpn. 1983 56 1867. I02 M. Touboul C. Bois and D. Mangin Acta Crystallogr. 1983 C39 685. I03 M. Touboul C. Bois and D. Amoussou J. Solid State Chern. 1983 48 412. I04 B. Frit G. Roult and J. Galy J. Solid State Chern. 1983 48 246. lo' F. Abraham G. Nowogrocki B. Jolibois and G. Laplace J. Solid State Chern. 1983 47 1. 106 H. Marton and J. Weiss Acta Crystallogr, 1983 C39 959. lo' N. Rey J. C. Jumas J. Olivier-Fourcade and E. Philippot Acta Crystallogr. 1983 C39 971. Al Ga In T1 75 is built up from sheets parallel to the 010 plane formed by SbS4 moieties which are linked together.The sheets are linked by weak Tl-.S (3.50-3.66A) Tl--Sb (3.60-3.73 A) and Tl...Tl (3.62 A) interactions. Bastow et ~1.'"~ report preliminary investigations on the pyridinium ennea-chlorodithallate(II1) complex. An X-ray structural investigation on the salt is in progress. Three papers have appeared reporting the crystal structure determinations on three thallium(rI1)-containing complexes. Following a comment on their pre- viously published results on the structure of [N(C4H9),][TlI4] Glaser et uZ."~ have re-refined the structure in the space group P2,/n and have achieved better results. Jeffs et al. have determined the structures of both [TlBr3(C,H,02)]''o and T1(C4Hs02)'TlBr~.1'1The structure of the former consists of distorted planar TlBr units bridged by dioxane chairs to form chains parallel to the c-axis.The geometry around the five-co-ordinate Tl is trigonal bipyramidal. The latter contains tetrahedral TlBr ions and chains of Tl+ions bridged by l,&dioxane molecules; the geometry around eight-co-ordinate Tl+is a distorted dodecahedron. The complex [TlR,(diox)] (diox = 1,4-dioxan) has been prepared"' by the reaction of TIC13 with LiR (R = 2,4,6-C6F3H2) or of [NBu4][T1&] with HBF (R = C6F5) and subsequent addition of dioxan. The displacement of dioxan by (a) neutral ligands leads to [TlR,L] (L = OPPh3 py PPh3 or Ph2PCH2PPh2); (b) anionic ligands affords Q[TlR,X] (Q = [NBu4]+ [N(PPh,),]+; X = C1- CN- NO, or CF3C0,); and (c) metal carbonylate gives Q[TIR3M*] (M* = [Mo(cp)(CO),]-(cp = 7-C,H5) [W(cp) (CO)3I- [CO(CO)4I- Or [Mn(C0)5I-).The crystal structures of complexes formed by dimethylthallium picrate with two isomers of dicyclohexano-18-crown-6have that in both there are [Me'Tl crown]+ cations consisting of linear Me2Tl entities normal to the plane through the six 0 atoms of the ligand and the T1 atom. Figure 3 shows the environment of the cation as found in each of the picrate isomers. The interaction of the components of the Se-Tl system in the concentration range 33.33-100atomY0 Se has been studied'I4 by DTA X-ray diffraction and micro- structural analyses. The formation of the compounds T12Se and TlSe with melting points of 388 "C and 340 "C respectively was confirmed.The solubility and composition of the solid phases in the Pb12-TlI-H20 system at 25 "Chave been investigated' Is isothermally. The double compounds 3TlI.Pb12 TlIePbI, and TlI-2Pb12 have been formed. New glass formation regions have been found in the TI-B-S(Se) and TI-Ge-S ternary systems close to the Tl-S(Se) side of the concentration triangle.l16 Small additions of B and Ge raise the glass formation temperature (Tg) in comparison with the glasses of TI-S(Se) systems. From the construction of equilibrium diagrams of GeSe2-T12Se GeSe-TlSe and GeSe,-TlSe I08 T. J. Bastow B. D. James and M. B. Millikan 1.Sofid State Chem. 1983 49 388. 109 J. Glaser P. L. Goggin M. Sandstrom and V. Lutsko Acra Chem Scand.1983 A37 437. I I0 S. E.Jeffs R. W. H. Small and I. J. Worrall Acta Crystallogr. 1983 C39 1628. Ill S. E.Jeffs R. W. H. Small and I. J. Worrall Acta Crystallogr. 1983 C39 1205. 112 R. Uson A. Laguna J. Antonio Abad and E. de Jesus J. Chem. SOC.,Dalton Trans. 1983 1127. 113 D. L. Hughes and M. R. Truter Acta Crystallogr. 1983 B39 329. 114 E. Yu. Turkhima and G. M. Orlova Russ. J. Inorg. Chem. 1983 28 764. I I5 R. M. Shklovskaya S. M. Arkhipov V. A. Kuzina and T. E. Volovkina Russ.J. Inorg. Chem. 1983,28 1058. I I6 S. A. Dembovskii M. N. Brekhovskikh E. K. Voitenkova and L. M. Klimashevskii Russ. J. Znorg. Chem. 1983 28 1068. S. M. Grimes Figure 3 (a) The [Me,Tl(cis-cisoid-cis-dicycZo~exano-18-crown-6 isomer A)]+ cation and (b) the [Me,Tl(cis-transoid-cis-dicyclohexano-18-crown-6 isomer S)]' cation asfound in the crystal structure of the picrate (Reproduced by permission from Acta Crystallogr.1983 B39 329) the following intermediates were formed Tl2Ge,Se5 T12GeSe3 Tl,GeSe, T12GeSe4 and TlGeSe,. Channel structures based on octahedral frameworks have been described,"' the crystal structures of TlTi,Se8 TlVsSe8 and TlCrSSe8 deter- mined and their relationship to Tlv5s8 TlCr,S5 hollandite and psilomelane lattices discussed. Two papers repo~-t"~*'~~ the investigation by DTA and X-ray diffraction methods of the thallium chalcogenide and mercury chalcogenide systems. The interaction between In Sb and Tl has also been investigated." The double molybdates and tungstates M+Bi(EO,) (where M = Ag or TI and E = Mo or W) have been synthesizedI2' by solid-phase reactions from the component oxides and their unit cell parameters have been determined.Finally the GeSe2- TlSbSe system has been synthesized by physicochemical methods.I2* It has a simple eutectic point at GeSe2(50 mole O/0)(210 * 5 "C). The GeSe2-TlSbSe system has a glass formation region at 40-70 mole YO GeSe,. I17 M. B. Babanly and N. A. Kulieva Russ. J. Inorg. Chem. 1983 28 877. 118 K. Klepp and H. Boller J. Solid State Chem. 1983 48 388. 119 M. M. Asadov Russ.J. Inorg. Chem. 1983,28 1025. M. M. Asadov Russ. J. Inorg. Chem. 1983 28 303. 121 P. V. Klevtsov A. P. Perepelitsa and R. F. Klevtsova Russ. J. Inorg. Chem. 1983 28 363. 122 Z.G. Makoskaya and E. G. Zhukov Russ. J. Inorg. Chem. 1983 28,612.

ISSN:0260-1818    

DOI:10.1039/IC9838000061

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

5 C,Si Ge Sn Pb; N P As Sb Bi By P. G. HARRISON Department of Chemistry University of Nottingham University Park Nottingham NG72RD 1 General A new electronegativity scale for the elements of Group IV has been estimated from the observed bond distances in the bivalent and tetravalent halides. Predicted values are C 2.6; Si 1.9; Ge 2.5; and Sn 2.3.' 2 Carbon Studies of the reaction of atomic carbon with both water2 and ammonia3 have appeared. In the former study the results of experimental and theoretical investiga- tions were compared. The theoretical study involved both 'Dand 3P states of carbon. For C ('0)atoms the process having the lowest activation enthalpy is cleavage of an initially formed carbon-water complex to CO and H2 along a closed-shell surface (AH*= 5.2 kcal mol-').Rearrangement of the closed-shell car- bon-water complex to hydroxymethylene has AHS = 11.6 kcal mol-'. For the triplet carbon atoms the most favourable reaction of the initial carbon-water complex was simply dissociation to C + H20. The enthalpy for rearrangement of the C(3P)-H20 complex to hydroxymethylene was 22.8 kcal mol-'. The barriers to rearrangement of singlet and triplet hydroxymethylene to formaldehyde were similar (38.9 and 41.3 kcal mol-' ). Experimental data confirmed the general theoretical predictions with atomic carbon generated from the thermolysis of 5-diazotetrazole reacting with water to give carbon monoxide (9.5%) and formaldehyde (2.4%) whilst addition of oxygen a scavenger of triplet carbon atoms increases the CO yield to 53.7% leaving the yield of formaldehyde unchanged.The reaction with oxygen alone produces only CO (47%). In the reaction with ammonia arc-generated atomic carbon affords methylenearnine H2C=NH by insertion into the N-H bond which further produces HCN. The second principal mode of reaction is hydrogen abstrac- tion yielding CH2 which reacts with NH3 to produce methylamine. Hydrolysis of the non-volatile residue from the reaction produces the amino-acids glycine alanine N-methylglycine and aspartic acid. Serine is also formed when water is included with the reactants. Hydrogen cyanide polymer is not a major precursor for amino-acid formation. The detailed reaction pathway for the hydration of ketenimine CH,=C=NH by H20 and (H20)2 has been investigated by ab initio methods.The preferred reaction pathway is with the water dimer through a 'pre-association' ' I. Hargittai and C. Bliefert Z. Nuturforsch. Ted B,1983 38,1304. ' S. N. Ahmed M. L. McKee and P. B. Shevlin J. Am. Chem. Soc. 1983 105 3942. P. B. Shevlin D. W.McPherson and P. Melius J. Am. Chem. SOC. 1983 105 488. 77 P. G. Harrison mechanism where a small amount of initial bonding occurs via attack (by oxygen) at the central carbon atom of the ketenimine. Proton transfer to the P-carbon atom then occurs at or just after the transition state without any appreciable changes in the C-0 bond distance. The reaction is therefore concerted but highly asyn- chronou~.~ Ab initio methods have also been employed in the study of the structures stabilities and bonding in a,w-dilithioalkanes' and allylsodium allyl-lithium and allylmag- nesium hydride.6 The doubly-bridged structure ( 1) was found to be the lowest-energy geometry for 1,3-dilithiopropane.Conversion of ( 1) into an allyl-lithium-LiH com-plex is exothermic by 29.0 kcal mol-'. Whereas the second lithiations of ethane and propane are favourable thermodynamically both 1,2-dilithioethane and 1,3-dilithiopropane are unstable towards conversion into LiH complexes. MNDO struc- tures for the dimers of the a,o-dilithioalkanes indicate opened tetrahedral geometries. Allyl-lithium and allylsodium are predicted to have symmetrically bridged structures (2) whereas allylmagnesium hydride prefers an unsymmetrical geometry although the barriers for 1,3 MgH shift and CH2 group rotation are quite low (3).In contrast to diphenylcarbene and essentially all substituted diphenylcarbenes which have central C-C-C bond angles of ca.150" dimesitylcarbene (4) is much closer to linearity than unhindered carbenes. When formed from dimesityl-diazomethane in n-octane or 1,l -diphenylethylene glasses dimesitylcarbene is quite persistent at 77 K showing no sign of decay over a period of 4-5 hours.7 Addi- tionally dimesitylcarbene appears to be unique amongst the diarylcarbenes thus far investigated since its triplet state cannot readily convert into the singlet state.' A new oxide of carbon tricarbon monoxide has been observed amongst the products of the pyrolysis of (5)at 1000 "C (Scheme 1).H. /H (2) M = Li or Na M. T. Nguyen and A. F. Hegarty J. Am. Chem. SOC.,1983 105 381 1. P. von R. Schleyer A. J. Kos and E. Kaufmann J. Am. Chem. SOC.,1983 105 7617. T. Clark C. Rohde and P. von R. Schleyer OrganometaNics 1983 2 1344. ' A. S. Nazran E. J. Gabe Y. LePage D. J. Northcott J. M. Park and D. Griller J. Am. Chem. SOC. 1983 105 2912. * A. S. Nazran and D. Griller J. Chem. SOC.,Chem. Commun. 1983 850. 79 C Si Ge Sn Pb; N P As Sb Bi o=c=ctlx 0 I C30 + C02 + MeCOMe + CO Scheme 1 Observed microwave frequencies for the new oxide are very close (1 part in 600) to those predicted for C30 by ab initio MO calculations. The data are fully consistent with a linear molecule whose electronic structure is well represented by the classical resonance form -C=C-C=O+.9 The 'ZZ electronic ground states of OCCO and SCCS have been studied by using non-empirical molecular structure theory which predicts the presence of strong chemical bonds in these molecules." The ability of CO to form a radical-anion CO'- which can react further with CO or C0'- with the formation of C-C bonds has been suggested by literature data on (i) the reaction of CO with alkali metals (ii) the electrochemical reduction of CO to squarate dianion (6) and (iii) adsorption of CO on metal oxides." Lithium atoms react spontaneously with CO to form Li+C02- and Li:+C022- in inert gas matrices.Li+C204- is also formed in an argon matrix. Li+C02- exhibits two structures in solid argon. One has a ring structure in which the metal interacts symmetrically with the two oxygen atoms whilst in the second isomer the lithium atom is bonded to only one of the two oxygen atoms.The C form rearranges on photolysis with a Nernst glower i.r. source to the C,,form. Similarly Li+C,O,- is converted photolyti- cally into an LiC02:C02 adduct. Li,2+C022- is produced when the concentration of alkali metal is high as a result of the reaction of dilithium or two lithium atoms with C02. Lithium oxalate is formed in concentrated matrices. A valence bond angle of 125.7" was calculated for C02-.12 0 4c-c / I 2-1 c-c 0/\ 0 (6) Methylenesulphurtetrafluoride CH,=SF4 has been synthesized by bromine- lithium exchange on BrCH2SF at low temperatures with subsequent LiF elimination.The compound is a colourless gas and has an essentially trigonal bipyramidal geometry with the methylene group occupying an equatorial site. The double bond undergoes addition reactions with polar molecules such as HF HCl HBr IC1 BrOSeF, HgF, AsF, and BrSF to give the cis adducts X-CH,-SF,-Y. In some cases elimination of SF with the formation of the carbene was 0b~erved.l~ R. D. Brown F. W. Eastwood P. S. Elmes and P. D. Godfrey J. Am. Chem. SOC.,1983 105 6496. lo G. P. Raine H. F. Schaeffer and R. C. Haddon J. Am. Chem. Soc. 1983 105 194. I' P. W. Lednor and P. C. Versloot J. Chem. SOC.,Chem. Commun. 1983 284. l2 Z. H. Kafafi R. H. Hauge W. E. Billups and J. L. Margrave J. Am. Chem. Soc. 1983 105 3886. l3 G. Kleemann and K. Seppelt Chem. Ber. 1983 116 645.P. G. Harrison The reaction of Ru(CO),( PPh3)3 with Cd(CF,),( MeOCH,CH,OMe) produces the zero-valent CF,-complex Ru( =CF,)(CO),( PPh3) which has a much reduced reac- tivity towards nucleophiles compared with an analogous Ru"-CF2 c~mplex.'~ The gas-phase pyrolyses of vinyl azide and 1 H-1,2,3-triazole have been examined by p.e. spectroscopy. In accordance with the predictions of MNDO hypersurface studies vinyl azide in its lowest thermal decomposition channel splits off nitrogen to yield predominantly 2H-aziridine which at higher temperatures rearranges to the most stable C2H3 N isomer acetonitrile (Scheme 2).15 Azidotrifluoromethane Scheme 2 reacts readily with halogen fluorosulphates and peroxydisulphuryl difluoride to form the novel compounds CF3NX(OS02F) (X = F C1 Br or OS0,F) in high yield.Reactions of the azide with ClF and BrF at ambient temperature furnish CF3NFC1 and CF3 N=NCF3 respectively but under similar conditions no reaction occurred with Cl, Br, HF or NCl. Photolysis produces CF3N=CF2 and (CF3),NN(CF3) as the major products.'6 N,N'-Dihalogenoethanediimidoyldifluorides XN=CF-CF=NX (X = C1 or Br) have been prepared simply from (CN), X2 and HgF,. Other products which were identified in the reactions included C12 N -CF2CF2- NC12 C1 N=CF-CF2- NCl, Br2N-CF2CF2-NBr, and BrN=CF-CF,-NBr,. l7 The electrophilic halides and pseudohalides XOS02F (X = C1 Br or OS0,F) add in high yield to CF2=NF to form FS020CF2NFX. Other electrophiles such as CF30F CF30C1 FOSO,F Cl, Pr, and I give no reaction under the same conditions although FOS0,F gave a small yield of the addition product FS020CF2NF2 on heating.The in situ formation of CF,NF- from CF2=NF and MF (M = K or Cs) in the presence of Cl and Br results in the formation of CF3NXF (X = C1 or F). The reactions with the imines CF3CF=NF and C2F5CF=NF proceed similarly.18 Treating CF3COCl with Me2NNH, H2NC(S)NH2 and H2NC(0)NH2 in the presence of CsF affords CF3C(0)- NH NMe CF3 C( 0)N HC(S)NHC( 0)C F, and CF,C( 0)NHC(S)N H and CF,C(O)NHC(O)NH, respectively. With hexafluoroacetone Me NNH yields CF3C( =NNMe2)CH=C(OH)CF3.'9 Cyanoformyl chloride (7) is formed in high yield by heating 2-chloro-2-( chlorothioimino)acetyl chloride at 800 "C in uacuo. Some reactions are shown in Scheme 3.20 The first phosphaketene stable at room temperature P-mesitylphosphaketene (8) has been isolated as orange crystals from the reaction shown in Scheme 4.,' A blue-black first-stage graphite fluoride C F (5 k x 2 2) in which the planar carbon-atom sheets of graphite are preserved has been made by intercalation of I4 G.R. Clark S. V. Hoskins T. C. Jones and W. R. Roper J. Chem. SOC.,Chem. Commun. 1983 719. H. Bock R. Dammel and S. Aygen J. Am. Chem. SOC.,1983 105 7681. l6 C. J. Schack and K. 0. Christie Inorg. Chem. 1983 22 22. A. Waterfield W. Isenberg R. Mews W. Clegg and G. M. Sheldrick Chem. Ber. 1983 116 724. S. C. Chang and D. D. DesMarteau Inorg. Chem. 1983 22 805. 19 H. M. Marsden K. Yasufuku and J. M. Shreeve Inorg. Chern. 1983 22 1202.20 R. Appel and M. Siray Angew. Chem. Int. Ed. Engl. 1983 22 785. *I R. Appel and W. Paulen. Angew. Chem.. In;. Ed. Cngl. 1983 22 785. C Si Ge Sn Pb; N P As Sb Bi 0 ‘C-CN +pyridine O‘C-CN EtOH -SCI, c1’ -pyndine-HCI H5C20/ (7) ’”/ LJ lH+ \ 0 N-C-CN .. w NYN COCl Scheme 3 /-( +CI,CO SitP(SiMed2 -Me,SiCl ’ Me,Si ’ ‘c1 Scheme 4 graphite with fluorine in the presence of liquid hydrogen fluoride at ca. 20 “C the oxidation proceeding bia a highly conducting second-stage salt C,2+HF2-.22 Graphite-fluorine intercalates have also been prepared in the absence of HF by exposing highly oriented pyrolytic graphite to neat fluorine gas. The rate of intercala- tion in this case is rather slow and depends strongly on the fluorine pressure although the presence of catalytic amounts of AsF, IF, or OsF considerably accelerates the reaction.X-Ray diffraction studies indicate the formation of second- third- and fourth-stage compounds ; the nature of the intercalating species however was not known.23 Reaction of SbCl with graphite at room temperature results in the forma- tion of a dilute first stage intercalate consisting of several species including SbCl, SbC152- SbC16- and SbC12-.24 The course of the intercalation has been monitored in situ by Raman spectro~copy.~~ The reaction of the potassium intercalate C8K with varying amounts of mercury allows the preparation of a series of compounds of general formula CgKHg,.26 The potassium ions in C3& can react with the three-dimensional cryptand 4,7,13,16,2 1,24-hexaoxa- 1,l O-diazabicyclo[8.8.8]hexa-cosane (‘K222’) to yield a first-stage intercalation compound with a very large interlayer spacing (15.5 A) suggesting that the potassium ions are probably within the macroheterobicyclic cage.27 22 T.Mallouk and N. Bartlett 1.Chem SOC.,Chem. Commun. 1983 103. 23 I. Palchan D. Davidov and H. Selig J. Chem. SOC., Chem. Commun. 1983 657. 24 W. Jones P. Korgul R. Schlogl and J. M. Thomas J. Chem SOC.,Chem. Commun. 1983 468. 25 R. Schlogl W. Jones and J. M. Thomas J. Chem. SOC., Chem. Commun. 1983 1330. 26 M. Rabinovitz H. Selig and J. Levy Angew. Chem. Int. Ed. Engl. 1983 22 53. 27 R. Setton F. Beguin L. Facchini M.F. Quinton A. P. Legrand B. Ruisinger and H.P. Boehm 1. Chem. SOC., Chem. Commun. 1983 36. P. G Harrison 3 Silicon and Germanium Reactive Intermediates.-The chemistry of reactive silicon intermediates is passing through a particularly interesting phase. The recent isolation of two stable disilene derivatives tetramesityl- and tetrakis(2,6-dimethylphenyl)-disilene,in the past two years has been followed by the crystal-structure determination of one of them and also by the generation of other though less stable examples. Tetramesityldisilene adopts a trans-bent geometry in the crystal with an Si=Si bond length of 216pm about 18-20 pm shorter than typical Si-Si single bond distances. Two of the cis aromatic rings are only slightly twisted relative to the approximate plane of the two silicon and four neighbouring carbon atoms whereas the other two are nearly perpendicular to this plane.28 The solid 29Si n.m.r.spectrum of this disilene (uI1 180 u2227 and u,,-15 p.p.m. downfield from Me,Si) shows an anisotropy compar- able to that of the solid 13Cspectrum of ethylene (uI 234 u22120,and a3,24 p.p.m. downfield from Me,Si). In contrast the solid 29Si n.m.r. spectrum of tetramesityl-disilane exhibits a much smaller anisotropy similar to that shown in the 13Cspectra of alkanes. Thus it appears that the electronic structure of the Si=Si double bond does indeed bear a close resemblance to that of the C=C double bond.29 Other methods for the generation of disilene derivatives include the reduction of 1,2- dihalogenodisilanes using alkali-metal naphthalide~~’ and the photolysis of cyclo- tri~ilanes~”~~ or strained bridgehead molecules such as 7,7,8,8-tetra-t-buty1-7,8-R (9) R = OMe (10) R = OH + 28 M.J. Fink M. J. Michalczyk K. J. Haller R. West and J. Michl J. Chem. Soc. Chern. Commun. 1983 1010. 29 K. W. Zilm D. M. Grant J. Michl M. J. Fink and R. West Orgnnornetallics 1983 2 193. 30 M. Widenbruch A. Schafer and K. L. mom 2.Naturforsch. Ted B 38 1983 1695. 3’ H. Watanabe T. Okawa M. Kato and Y. Nagai J. Chern. Soc. Chem. Commun. 1983 781. 32 S. Masamune H. Tobita and S. Murakami J. Am. Chem. Soc. 1983 105 6524. C Si Ge Sn,Pb; N P As Sb Bi disilabicycl0[2.2.2]0cta-2,5-diene.~~By these methods the tetra-t-butyl- tetra-i-propyl- tetrakis( 1-ethylpropyl)- and tetraneopentyl disilenes have been generated and can be trapped by the usual trapping reagents.Thus for example tetra-t butyldisilene gives the addutcts (9) and (10) with methanol and water respectively and the two products (11) and (12) with 2,3-dimethylbutadiene (Scheme 5).33 Photolysis of the cyclotrisilanes affords both the disilene and the corresponding silylene and hence trapping experiments afford products arising from both species as shown for example in Scheme 6. Several reactions of tetramesityldisilene have R2 R,Si -SIR R2Si-H Si hu b R,s~-s~R~ I 1 I /\ excess MeOH in H OMe + OMe methylcyclohexane R = 1-EtPr Scheme 6 been reported and are summarized in Scheme 7. Upon photolysis the acetone adduct (13) rearranges to the 1,3-isomer (14) probably via cleavage to the silanone and silaethene followed by ring closure in the opposite sense (Scheme 8).34On irradiation Mes2Si-SiMes, I I Mes2SiC1SiHMes2 0-CR; R;CO or CI, pentane \ HY c12 MestSi\ NO\ ,SiMes 0 Mes,Si=SiMes2 benzene+ (Mes2SiCl) 0 / \ phcrcY YH Mes,Si-SiMes Mes2Si(0R)SiHM es I1 HC=CPh Mes = 2,4,6-trimethylphenyI; R = H Me or Et; R' = Me or Ph Scheme.7 Mes,Si-0 Mes2Si-CR2I.I h, 254 nm -[Mes,Si=O] + [Mes,Si=CR,] -* Mes2Si-0 R2C-SiMes,I t R=Me Scheme 8 (14) of tetramesityldisilene in pentane solution transformation to Mes HSiSiHMesz occurs (the product expected by abstraction of hydrogen by silyl radicals) and therefore suggests radical character for the excited state of the disilene.Reaction of a solution of tetrakis(2,6-dimethylphenyl)disilene in methylcyclo-hexane at -196 "Cwith diazomethane results in the formation of the 1,2-disilacyclo-propane derivative (15) which on photolysis in the presence of trapping reagents 33 S. Masamune S. Murakami and H. Tobita Organometallics 1983 2 1464. 34 M. J. Fink D. J. DeYoung R. West and J. Michl J. Am. Chem. Soc. 1983 105 1070. P. G Harrison material Me H +R2Si/ R2SI/\ \ OMe OMe Scheme 9 gives products consistent with the formation of both silaethene and silylene (Scheme 9).35 Two other stable disilacyclopropanes 1,1,2,2-tetramesity1-3-bis(trimethyl-sily1)methylene-and 1,1,2,2-tetramesity1-3-phenyl( trimethylsily1)methylene-1,2-disilacyclopropane (16) have been prepared by the addition of dimesitylsilylene to the silapropadiene derivatives (17) (Scheme 1 O).36 R R ,SiMe \ C C=S=Si(Mes) +(MeS),Si II -/ C Me Si /\ (17) R =Me,Si or Ph (Mes),Si-Si(Mes) Scheme 10 The crystal structure of a stable silaethene was reported in 1982.37 A second stable silaethene has been described by Wiberg,38 in which the Si=C double bond is stabilized by bulky silyl groups.Synthesis of (18) is achieved by the elimination of lithium fluoride from the precursor (19) at temperatures above ca. 100 "C (Scheme 11). However at room temperature in the presence of Me3SiCl (19) is transformed rapidly into (18) which can be obtained in crystalline form by slow recrystallization Me SiMe(Bu') Me Si M e(BuI) I I Me-Si-C-SiMe h \/\SiMe, -LiF I1 F Li Me (19) (18) Scheme 11 35 S.Masamune S. Murakami H. Tobita and D. J. Williams J. Am. Chem. SOC. 1983 105 7776. 36 M. Ishikawa H. Sugisawa M. Kumada T. Higuchi K. Matsui K. Hirotsu and J. Iyoda Organometallics 1983 2 174. 37 A. G. Brook S. C. Nyburg F. Abdesaken B. Gutenkunst R. Krishna M. R. Kallury Y.C. Poon Y.M. Chang and W. Wong-Ng J. Am. Chem. SOC.,1982 104 5667. 38 N. Wiberg and G. Wagner Angew. Chem. Int. Ed. Engl. 1983. 22 1005. C Si Ge Sn Pb; N P As Sb Bi from diethyl ether at -78°C. Decomposition occurs within a few days at room temperature but rapidly at 100 "C to afford secondary products which contain dimers of (18). Several reactions of (18) are shown in Scheme 12.38 'X Me2Si-CR 'R2 Me Si-CR' R2 I1 0 F BF2 R' = SiMe,; R2 = SiMe(Bu') Scheme 12 The desorption of trimethylsilane silacyclobutane and silacyclohexane from the ( 1 10) surface of palladium metal is accompanied by dehydrogenation to silaethylene sialcyclobutadiene and silabenzene respectively which suggest a novel practical method for the synthesis of these molecules.39 The conversion of silaspiro[3.3]cyclo- heptane into the silacyclopentenes (20) and (21) appears to proceed via a thermally induced silaethene to silylene rearrangement (Scheme 13)."O The thermal decomposition of silacyclobutane leads not only as previously sug- gested to the silaethene and ethene but also to afford the silylenes SiH2 and SiHMe.41 Similarly although the direct photolysis of 1,l -dimethylsilacyclobutane results predominantly in decomposition to ethene and the silaethene in the presence of benzene decomposition to cyclopropane and dimethylsilylene also occurs due to sensitization of the silacyclobutane by triplet benzene.42 Photolysis of dibenzo- 1,1,2,2-tetramethyl-1,2-disilacyclohexa-3,5-dieneand its germanium analogue (22) results in the exclusive extrusion of the respective silylene or germylene via a route involving intramolecular ips0 aromatic silylation (Scheme 14).43 Dimesitylsilylene 39 T.M. Gentle and E. L. Muetterties J. Am. Chem. SOC.,1983 105 304. 40 T. J. Barton G. T. Burns and D. Gschneider Organometallics 1983 2 8. 41 R. T. Conlin and R. S. Gill J. Am. Chem. SOC.,1983 105 618. 42 C.George and R. D. Koob Organomeiallics 1983 2 39. 43 M. Kira K. Sakamoto and H. Sakurai J. Am. Chem. Soc. 1983 105 7469. P. G. Harrison ~e,~-hi~e (22) M = Si or Ge Q4J MMe Scheme 14 is generated by both the photolysis and pyrolysis of the oxasilacyclopropanone (23) along with the indanone (24) and can be trapped by conventional techniques. The benzosilacyclobutene (25) was formed in quite large yields (ca.40% ) in the pyrolysis reaction (Scheme I 5).44 Silylenes have been shown to undergo ring-closure reactions. (25) Scheme 15 Flash vacuum pyrolysis of methoxydisilanes has been employed to generate 1- 2- and 3-propenylsilylenes each of which affords silacyclobutane (siletene) products although probably via different mechanisms (Scheme 16):’ Methyl-5-( 1,3-pentadienylsilylene) reacts similarly (Scheme 17).46 The silylene to disilene re-arrangement has been further confirmed by generating Me SiMe2SiMeSi from 3-methoxyundecamethylpentasilane and obtaining the rearranged product Me2 SiSiMe( SiMe,).In addition the reverse rearrangement i.e. disilene to silylene has also been dem~nstrated.~’ The relative energies of isomers in the Si2H2have been calculated by ab initio SCF and electron correlation calculations. For the singlet ground-state the global minimum is a non-planar bridged structure (26) 44 W. Ando Y. Hamada and A. Sekiguchi J. Chem. SOC.,Chem. Commun.,1983 952. 45 G. T. Bums and T. J. Barton J. Am. Chem. Soc. 1983 105,2006. 46 T. J. Barton and G. T. Bums Organometallics 1983 2 1.47 H. Sakurai Y.Nakadaira and H. Sakaba Organometallics 1983 2 1484. C Si Ge Sn Pb; N P As Sb Bi Me >Me Me3Si-Si I Me -Me SiOMe 680°C d90/~ (10-4 ton) I H-Si rT CH insertion >Me Me-Si 680torr) Ae “C 37% \ Me-Si ryMe2 rfH3+ qMe + -Si Si I / / Me Me Me Scheme 16 700°C ton) Me,SiOMe + Me,Si-Si Si Me0/\Me Me / I 0-rLH,-q Si -Si / Me/\H Me Me / (13%) I Scheme 17 P. G. Harrison followed by H2SiSi (27) and trans-bent HSiSiH (28). Both H2SiSi and trans-bent HSiSiH are predicted to be local minima. In the case of the triplet ground-state H2SiSi (27) is the global minimum with the trans-bent structure (28) and a planar bridged structure (29) as local minima.48 The potential energy hypersurface for the reaction of SiH with H2 to give SiH4 has been investigated by a priori quantum mechanical methods and leads to acceptable agreement with the experimental activation energy.49 The heats of formation of 1-methylsilaethene and dimethylsily- lene of 18 and 46 kcd rno1-I have been obtained by ion cyclotron double resonance spectroscopy contradicting previous studies which indicated that the silylene was favoured in the thermal eq~ilibrium.~' Highly sophisticated calculations have been carried out on the SiCH2 system.The absolute minimum on the potential energy hypersurface is the silylidene :Si=CH2 which lies ca. 50 kcal mol-I below the linear sila-acetylene. The vinylidene isomer H,Si=C is either a shallow minimum or more likely not a genuine relative minimum at all.Sila-acetylene is predicted to have a trans-bent equilibrium geometry with a silicon-carbon bond distance of 1.635 A about 0.08 8 shorter than a 'standard' Si=C double bond distance. The bond order is suggested to be intermediate between two and three.5' Ab initio calculations on the addition of hydrogen chloride to silaethene predict that the reaction takes place with a small overall barrier and via the formation of a complex and a two-centre transition-state in which the Si-C bond distance is lengthened.' Both E and 2 isomers of 1 -methyl-1-phenyl-2-neopentylsilylene are generated by the reaction of t-butyl-lithium with chloromethylphenylvinylsilane,and can be trapped as [4 + 21 adducts by ~yclopentadiene.~~ Both silicon dichloride and silicon dibromide have been studied by electron diffraction and have XSiX bond angles of 102.7".54Thermally-generated dimethylgermylene Me,Ge undergoes concerted 1,4-addition of the linear [2 + 41 cheletropic type to give certain 1,3-dienes under (70-1 mild conditions in solution 50 "C) e.g.Scheme 1KS5 Me,Ge i-xh Scheme 18 48 H. Lischka and H. J. Kohler J. Am. Chem. SOC.,1983 105 6646. 49 R. S. Grev and H. F. Schaeffer J. Chem. SOC.,Chem. Commun. 1983 785. 50 C. F. Pau W. J. Petro and W. J. Hebre J. Am. Chem. SOC.,1983 105 16. 5' M. R. Hoffmann Y. Yoshioka and H. F. Schaeffer J. Am. Chem. SOC.,1983 105 1084. 52 S. Nagase and T. Kudo J. Chern. SOC.Chem. Commun. 1983 363. 53 P. R. Jones M. E. Lee and L. T. Lin Organometallics 1983 2 1039. 54 I. Hargittai G. Schultz J. Trernmel N. D. Kagramanov A. K. Maltsev and 0. M. Nefedov J. Am. Chem. SOC.,1983 105 2895. 55 M. Schriewer and W. P. Neumann J. Am. Chem. Soc. 1983 105 897. C,Si Ge Sn Pb; N P As Sb Bi 89 Halogenogermylenes react readily with some dinuclear transition-metal carbonyl compounds {Co,(CO), Mn2(CO),o [Fe(C5H5)(C0)2]2 etc.} to give the correspond- ing insertion products. However in contrast insertion into Group IVB metal-transition-metal bonds results in the formation of unstable adducts and the formation of the first germylenes with germanium-transition-metal bonds e.g. Scheme 19.56 Such germylenes undergo normal types of germylene reactions such as addition to dienes which unusually are thermally reversible (Scheme 20).GeF + Ph,SiCo(CO) + + Ph,SiF + F-Ge-Co(C0) GeF + 2Ph3SiCo(CO) + 2Ph,SiF + [(CO),Co],Ge Scheme 19 Y=F Y = (CO),Co Scheme 20 Tetravalent Compounds.-Insertion of the carbene :CF2 into the Si-Si bond of (FMe,Si) leads to the formation of (FMe2Si)2CF2 which undergoes Si-rather than C-alkylation with MeMgCl or MeLi. Reaction with LiA1H4 affords the corresponding silanes. In all cases the CF2 group remains inert. However the ylide (FMe2Si),C=PMe2-PMe2 is formed on treatment with Me,SiPMe2 (Scheme 2l)?' ~~e2 (FMe,Si),CF +~~e~ {(FMe,Si),CF-FMe,} I (FMe Si),C= PMe2- PMe +M$te2{ (FMe Si),C= PMe F} Scheme 21 The isomerization of the cyanate (Me3Si)3CSiMe2(0CN) to the corresponding cyanate in Ph20 at 195 "C is second order in cyanate and is catalysed by IC1 in CCI and by NaOMe in methanol.58 Reactions of 2-bis( trimethylsily1)methylpyridine with butyl-lithium in ether sol-vents and CuCl yields the thermally robust dinuclear complexes (30) (M = Li or Cu) in which the metal is not involved in electron-deficient bonding.59 The interaction 5b A.Castel P. Riviere J. Satge J. J. E. Moreau and R. J. P. Corriu Organometallics 1983 2 1498. 57 G. Fritz and H. Bauer Angew. Chem. Inr. Ed. EngL 1983 22 730. 58 C. Eaborn Y. El-Kaddar and P. D. Lickiss 1.Chem. SOC.,Chem. Commun. 1983 1450. 59 R. I. Papasergio C. L. Raston and A. H. White J. Chem. SOC.,Chem. Commun. 1983 1419. P.G. Harrison of FeI with excess Me3SiNC in thf yields ~is-[Fe(CNSiMe~)~1~] (31).60The struc- tures of two silylmethyl-lithium compounds have been determined. That of tris(trimethylsily1)methyl-lithiumthf solvate is an ate complex with [Li( thf),] cations and {Li[C(SiMe3)3]2} anions in which the lithium bridges the two organic residues.61 In contrast crystals of the thf adduct of tris(phenyldimethylsily1)methyl-lithium comprise monomeric {Li[C(SiMe,Ph),](thf)) species in which the lithium is covalently bonded to oxygen and to the central carbon of the [(Me2PhSi)3C] group and intersects strongly with the ips0 carbon atom of one of the phenyl groups without significantly distorting the hydridization of that atom (Figure 1).62 Two "C(15) Figure 1 Molecular structure of Li[C(SiMe Ph),](thf) (Reproduced from J.Chem. SOC.,Chem. Commun. 1983 1390) C N SiMe R. A. Jones and M. H. Seeberger J. Chem. SOC.,Dalton Trans. 1983 181. 6' C. Eaborn P. B. Hitchcock J. D. Smith and A. C. Sullivan J. Chem. SOC.,Chem. Commun. 1983 827. C. Eaborn P. B. Hitchcock J. D. Smith and A. C. Sullivan J. Chem. Soc. Chem. Commun. 1983 1390. C Si Ge Sn Pb; N P As Sb Bi 91 independent determinations of the structure of the ether solvate of the lithium disilazane {Li[N( SiMe,),](OEt,)), have both of which agree. The lattice contains dimeric molecules with the silazane groups acting as bridging ligands between the two three-coordinated lithium atoms. Several new compounds containing the Si -N -transition-metal linkage have been synthesized most of which are accompanied by crystal-structure determina- tions.The reaction of LiN(SiMe2CH,PR2)2 with either zirconium( IV) or hafnium( IV) chloride generates the new complexes MCl2[N(SiMe,CH2PR3),] (M = Zr Hf; R = Me Ph) in which both of the potentially terdentate ligands bind the Group IVA metal in a bidentate fashion only. The molecules thus contain both co-ordinated and unco-ordinated phosphines. Structural studies of the complex with M = Zr and R = Me show that the geometry at the central metal is distorted octahedral with trans-chloride and cis-phosphine ligands. The molecule is chiral in both the crystal and in solution by virtue of a 'gear' effect of the two bulky disilylamide ligand~.~' The dialkyls R,Zr[N( SiMe,),] (R = Me Et or CH,SiMe,) decompose thermally at 60 "C and lo- torr with elimination of the alkane (CH4 C2H6 or Me,%) to give the bridging carbene complex ZrCHSiMe,NSiMe,[N(SiMe,),], which has the dimeric structure (32) comprising three fused planar four-membered rings giving the molecule a 'tub' conformation.The hafnium dialkyls decompose in a similar manner although in this case the product could only be characterized as its pyridine Inadduct kfCHSiMezNSiMe3[N(SiMe3)2](CsHsN)2.contrast the titanium alk 1 Me Ti N(SiMe,),], is stable up to 190 "C; nevertheless the carbene complex iCHSiMe NSiMe,[N( SiMe34),], was obtained by the sodium-amalgam reduction of Cl,Ti[ N( SiMe3)J2 .66 The zirconium and hafnium carbene complexes react with 1,2-bis(dimethy1phys~hino)ethane (dmpe) at room temperature to give the bis(metallacycle) M[CH2SiMe2NSiMe3l2(dmpe).The same complexes can also be prepared from the dialkyls R,M[N(SiMe,),], and dmpe at 60 "C and are formally derived by addition of a y-CH bond of a [N(SiMe,),] group to a metal-carbon(car- bene) bond.The zirconium complex has idealized C2 symmetry with the two phosphorus atoms occupying two cis sites trans to the two nitrogen atoms and the two remaining trans sites occupied by the carbon atoms of the metallacycle rings in a distorted octahedral arrangement. The complex also reacts with carbon monoxide under pressure (19atm) at room temperature in pentane to give Zr[CC( =CH2)SiMe,NSiMe3],(dmpe).67The disproportionation of the hafnium complex HfC1[N(SiMe2CH2PMe2)2]2,with excess hafnium( IV) chloride results in the formation of the mono-amide complex HfC13 N( SiMe2CH PMe,) HfCl, which can be converted into Hf(BH4),[N(SiMe2CH2PMe2),] and Hf( BH,) by reaction with excess LiBH,.Reaction of the tetrahydroborate complex with Lewis bases yields the dinuclear complex {Hf[N(SiMe2CH,PMe,)2]}2(H),(BH4)3.68 The platinum complex Pt{P(=NBu')[N(SiMe,),]}, reacts with the alkenes C,Cl,H C2C14 C,H,(CN), and C2(CN) to afford the complexes (33)-(35)' respectively; the 63 P. M. Engelhardt A. S. May C. L. Raston and A. H. White J. Chem. SOC. Dalton Trans. 1983 1671. 64 M. F. Lappert M. J. Slade A. Singh J. L. Atwood R. D. Rogers and R. Shakir J. Am. Chem. SOC. 1983 105 302. 65 M. D. Fryzuk H. D. Williams and S.J. Rettig Inorg. Chem. 1983 22 863. 66 R. P. Planalp R. A. Andersen and A. Zalkin Organometallics 1983 2 16. 5? R. P. Planalp and R. A. Andersen Organometallics 1983 2 1675. 68 M. D. Fryzuk and H. D. Williams Organometallics 1983 2 162. P. G. Harrison complex (36) is obtained with diphenyla~etylene.~~ Both Me SiNSO and Me,SiN=S=NSiMe react with tin(1v) chloride to yield the 1 1 adduct Me3SiN=S=NSiMe3-SnCl, in which the silylsulphurdi-imide ligands chelates the tin.70 L C(CN)R L c’ \/ \/ Pt Pt /\ L C(CN)R L /\C (35) R =H \Ph R =CN (36) Four- and five-membered silylhydrazine ring compounds such as (37) and (38) are obtained by the reaction of N,N-bis( fluorasily1y)amines with dilithiated hydra~ines.~~ (39) can be prepared by Similar 1,3-diphospha-2,4-disilacylobutanes ring closure of fluorodialkylsilyl(t-buty1)phosphinesusing t-BuLi whilst ring closure of the bis(phosphane) (40) affords the 1,2,3-triphospha-4-sila-cyclobutane derivative (41).72 The reaction of silyliminofluorosulphates R,SiNSOF, with the salts [M(SO,),](AsF,) (M =Co Ni or Cu) in liquid sulphur dioxide results in the formation of the metal iminofluorosulphates M( NSOF2)2.73 Cyclocondensation of 1,2-dipotassium 1,2-di-t-butyldiphosphide with SiC1 leads to the formation of tetraphosphasilaspiro[2.2]pentane (42) as a mixture of stereoisomers the melt of which rearranges at temperatures of 135-155 “C to the silaphosphane (43).The structure of (43) is most unusual and comprises three-membered Sip2 four mem- bered [SizP2] and five-membered [Sip,] rings in the same m01ecule.’~ R R CMe /CM% P I R Si,,;\ R\ /R R\SrN,Si/R /Si /R R\Si/ ‘H Si /Si \ /\ \ R’k-N ‘\R R’P R R /P-H R/ R / \ I N H R CMe Me,C /\ H R (38) (39) (40) (37) 6Y 0.J. Scherer R. Konrad E. Guggolz and M. L. Ziegler Chem. Ber. 1983 116 2676. H. W. Roesky H. G. Schmidt M. Noltemeyer and G. M. Sheldrick Chem. Ber. 1983 116 1411. 70 ”W. Clegg M. Haase H. Hluchy U. Klingebiel and G. M. Sheldrick Chem. Ber. 1983 116 290. 72 W. Clegg M. Haase U. Klingebiel and G. M. Sheldrick Chem. Ber. 1983 116 146. 73 R. Hoppenheit R. Mews M. Noltemeyer and G. M. Sheldrick Chem. Ber. 1983 116 874. 74 M. Baudler T. Pontzen U. Schings K. F. Tebbe and M.Feher Angew. Chem. Int. Ed. Engl. 1983 22 775. C,Si Ge,Sn Pb;N P As Sb Bi CMe, I R = Bu' R CMe (42) (43) (41) Trichlorosilanol Cl,SiOH is formed by photolysis of C13SiH and oxygen in silicon tetrachloride uia a radical-chain pathway. The hydfoperoxide could not be detected.% Electron-diff raction studies of bis(methylsily1)ether and bis( dimethyl- sily1)ether in the gas phase has shown that the former has at least two conformers. The major one (64%) has the methyl groups twisted by 124" and 58" away from the positions in which the Si-C bonds are trans to Si-0 bonds. In the dimethylsilyl ether the silyl groups are twisted by 10 1" and 41O away from the symmetrical position in which both Si-H bonds are cis to Si-0 bonds so that the dimethylsilyl groups are staggered with respect to each other.76 The hydrolysis of dichlorosilane in dichloromethane solution either with a stoicheiometric amount of water at -30 to -20 "C or by slow controlled addition of a slight excess of water at 0 "C results in the formation of siloxanes of the type [HZSiO],.In the volatile fraction oligomers with n ranging from 4up to 23 were found.77 Tetramethyldisiloxane and poly(methy1- siloxane) react with chlorine to give 1,3-dichlorotetramethyldisiloxane and poly(methylchlorosiloxane) respectively which undergo substitution with sodium cyclopentadienide to afford the corresponding cyclopentadienyl derivatives. These in turn either with sodium metal or Bu"Li give anionic cyclopentadienide derivatives which react with TiC1,-2py to yield (44) and (45).78 (44) (45) Following the controversy over the claim of a square-planar geometry for bis( o-phenylenedioxy)silane the structures of two related compounds bis( 1,8-naph- tha1enedio~y)silane~~ and bis(tetramethylethylenedioxy)silane,80 have been deter- mined and further refute the original claim.In both the geometry at the spiro silicon atom is distorted tetrahedral the greater distortion observed in the second compound being attributed to the constraints of the five-membered ring rather than to any tendency towards planarization. The racemization of tris(tropolonato)silicon(rv) anion in 1,1,2,2-tetrachloroethaneand acetonitrile follows first-order kinetics and 75 R. Gooden Inorg. Chem. 1983 22 2212.76 D. W. H. Rankin and H. E. Robertson J. Chern. Soc. Dalton Trans. 1983 265. 77 D. Seyferth C. Prud'homme and G. H. Wisernan Inorg. Chem 1983 22 2163. 78 M. D. Curtis J. J. D'Emco N. Duffy P. S. Epstein and L. G. Bell Organornetallics 1983 2 1808. 79 W. Bibber C. L. Barnes D. van der Hlem and J. J. Zuckerman Angew. Chem. Inr. Ed. EngL 1983 22 501. 80 D. Schomburg Angew. Chern. Int. Ed. Engf. 1983 22 65. 94 P. G. Harrison is not accompanied by any detectable decomposition or ligand subsitutition but is promoted by trichloroacetic acid. A mechanism involving bond rupture to give five-co-ordinated intermediates was proposed.” The co-facially joined metallo- macrocyclic polymer {M(Pc)O) (Pc = phthalocyaninato; M = Si Ge or Sn) are precursors for a new class of electrically conductive polymers and their synthesis spectra and structural transport magnetic and optical properties have been reported.82983 The heavy-atom skeleton framework of germyl monothioacetate is almost planar in the gas phase with the Ge-S and C=O bonds in a mutually cis arrangement.84 Ab initio MO calculations using double 5 basis sets have shown that (46) is the lowest energy geometry for the adduct SiF4-NH3.85 The 1 1 adducts of trimethyl- iodosilane and trimethylbromosilane with pyridine comprise the four-co-ordinated [Me,Si.py]+ cation and halide anion.86 The silicon atom in 1-(trifluorosilyl)- 1,2,3,4- tetrahydro- 1,lO-phenanthroline is five-co-ordinated with a trigonal bipyramidal ge~metry.~’ Cyclopropyl- cyclobutyl- and cyclopentyl-trichlorogermaneshave been prepared by the organolithium or Grignard route from GeCl, and can be reduced to the corresponding germanes using LiA1H4.88 Diethyldichlorosilane reacts with alkali metals to produce the diethylcyclosilanes (Et,Si),(n = 4-8) the particular products obtained depending upon the alkali metal and conditions employed.With lithium in thf the major products are the n = 5 and n = 7 rings whereas the n = 4 ring is the major product from sodium in toluene. Photolysis of the n = 5-8 rings leads to the elimination of Et,Si and the formation of the next smaller ring.89 The reaction of (Et,Si) with 1.1 equivalents of sulphur at 50 “C gives high yields of (47) whereas reaction with 2 equivalents at 190°C affords (48) and (49) as the major products along with small amounts of (50).This latter heterocycle appears to arise from the reaction of (48/49) and sulphur which also produces diethylsilanethione [Et Si=S] as a reactive intermediate.” Reaction with alkynes in the presence of palladium catalysts results in ring expansion to yield 3,4,5,6-tetrasilacyclohexenes (5 1) and ultimately 1,4-disilacyclohexa-2,5-dienes (52). With isoprene two addition products (53) and (54) are formed. rn-Chloroperbenzoic acid causes rapid oxidation to the siloxanes (Et Si),O (n = 1-4). Ring-opening occurs with Clz Br, I, LiAlH4 HCl HBr H20 EtOH and acetic acid and slowly with phenyl-lithium to give 1,.l-disubstituted linear tetrasilanes.” Reaction of (C Me 1r),CI4 with triethylsilane gives initially (C,Me Ir),H2C12 and then (C Me,Ir( H),(C1)SiEt3 finally giving the complex C,Me,Ir( H),( SiEt3)2.92The symmetrically-bridged diruthenium complex (55) is obtained from the reaction of ” T.Inque Znorg. Chem. 1983 22 2435. 82 C. W. Dirk T. Inabe K. E. Schoch and T. J. Marks J. Am. Chem. Soc. 1983 105 1539. 83 B. N. Diel T. Inabe J. W. Lyding K. F. Schoch C. R. Kannewurf and T. J. Marks J. Am. Chem. SOC.,1983 105 1551. 84 E. A. V. Ebsworth C. M. Huntley and D. W. H. Rankin J. Chem. SOC.,Dalton Trans. 1983 835. 85 C. J. Marsden Inorg. Chem. 1983 22 3177. 86 K. Hensen T. Zengerly P. Pickel and G. Klebe Angew. Chem. Int. Ed. Engl. 1983 22 725. 87 G. Klebe K. Hensen and H. Fuess Chem. Ber. 1983 116 3125. 88 M.Dakkouri and H. Kehrer Chem. Ber. 1983 116 2041. 89 C. W. Carlson and R. West Organometallics 1983 2 1792. C. W. Carlson and R. West Organometallics 1983 2 1798. 9’ C. W. Carlson and R. West Organornetallics 1983 2 1801. 92 M. J. Fernandez and P. M. Maitlis Organometallics 1983 2 164. C,Si,Ge Sn,Pb; N P As Sb Bi 95 EtZ Et,Si”\I S Et,Si. Si Et2Si/”SiEt2 S I I Et,Si\ ,SiEt Et2SiNS\SiEt2I I S .,SiEt2St 2.072 Et2 Et2 Ru3(CO) and Ph2PCH,SiMe2H which on treatment with trifluoroacetic acid gives the mononuclear phosphinomethyldimethylsilanol complex (56).93The compounds OS~(CO)~~(S~XC~~), (X = Me or C1) have been isolated from the reaction of OS~(CO)~~ with the appropriate silane C1,XSiH at 140 “C under a carbon monoxide pressure (80 atm).The structure of the X = C1 complex has a crystallographic centre of symmetry with a linear SiOs3Si chain which is preserved in solution. The structure of 0s3(P-H)~(CO)~( SiC13)3 is different and has a triangular arrangement of osmium atoms which lie on a mirror plane with the silicon atoms also on the plane.94 The complex (OC)50sOs(C0)3(GeC13) is formed from the reaction of Os(CO) and GeC1,.95 The germanium-manganese complex (57) may be prepared in quite high yield by reaction of gaseous germane with solvent-stabilized (C,H,)Mn(CO) in the presence of traces of acid. (C,Me,)Mn(CO) gives exclus- ively the orange complex (p2-Ge)[(C,Me,)Mn(C0)2]2 having a strictly linear Mn-Ge-Mn skeleton. Solutions of (57) in thf react with diazomethane at low temperatures to afford brown air-stable crystals of the p3,7 methylenegermanediyl complex (58).The main product from the reaction of silane with (C5H,)Mn(CO),.thf was (59).96 Solid-state 29Si and 27Al n.m.r. with magic-angle spinning is now rather a standard technique for the investigation of silicate and aluminosilicate materials and several studies have appeared recently. The surface of dehydrated silica gel has been shown 93 M. J. Auburn R. D. Holmes-Smith S. R. Stobart M. J. Zaworotko T. S. Cameron and A. Kumari J. Chem. SOC.,Chem. Commun. 1983 1523. 94 A. C. Willis G. N. van Buuren R. K. Pomeroy and F. W. B. Einstein Inorg. Chem. 1983 22 1162. 95 F. W. B. Einstein R. K. Pomeroy P. Rushman and A. C. Willis J. Chem. Soc. Chem. Commun. 1983 854.96 W. A. Herrmann J. Weichmann U. Kusthardt A. Schaffer R. Horlein C. Hecht E. Voss and R. Serrano Angew. Chem. Int. Ed. Engl. 22 1983 979. P. G. Harrison to comprise separate regions resembling the 100 and 11 1 faces of P-cri~tabolite:~ and a double-ring silicate has been identified for the first time in the ZSM-5 synthesis mixture.98 A correlation between the average Si-0-T (T = tetrahedral atom) and the associated isotropic 29Si chemical shift in zeolite materials has been e~tablished,~~ but 29Si spin-lattice relaxation times in aluminosilicates vary over three orders of magnitude and can be extremely long.'00 Eight distinct tetrahedral sites for silicon have been identified in freshly crystallized (hexagonal) synthetic cordierite Mg2Al4Si5Ol8 and have been assigned as four in the chain manifold and four in the six-membered aluminosilicate rings.However there are only two sites one in the rings and one in the chains in the aged (orthorhombic) product. The Si :A1 ratios within each manifold can also be determined from the spectra which also allow the course of Si,Al ordering to be charted as thermodynamic equilibrium is approached."' The reaction of synthetic zeolite Na-Y with SiC14 vapour at 560 "C yields an essentially aluminium-free faujasite structure which is highly crystalline and whose n.m.r. spectrum exhibits a single peak characteristic of regular Si(4Si) ordering. The 27Al spectrum of the dry dealuminated material shows two peaks one due to residual lattice aluminium and the other to AlC14-.The 27Al spectrum of washed dealuminated zeolite Y contains two peaks one also due to residual aluminium still on tetrahedral sites in the lattice and an additional peak due to octahedrally co-ordinated cationic aluminium in the zeolite channels. lo* 4 Tin and Lead Bivalent Compounds.-Reaction of tin( 11) chloride with Li( CPh=CPh2) at -78 "C in diethyl ether-hexane-thf gives a deep-red solution believed to contain the 97 D. W. Sindorf and G. E. Maciel J. Am. Chem. Soc. 1983 105 1487. 98 G. Boxhoorn 0.Sudmeijer and P. H. G. van Kasteren J. Chem. Soc. Chem. Commun. 1983 1416. 99 R. H. Jarrnan J. Chem. Soc. Chem. Commun. 1983 512. I00 P. F. Barron R. L. Frost and J. 0. Skjemstad J. Chem. SOC.,Chem. Commun 1983 581. 101 C. A.Fyfe G. C. Gobbi J. Klinowski A. Putnis and J. M. Thomas J. Chem. Soc. Chem. Cornmun. 1983 556. 102 J. Klinowski J. M. Thomas C. A. Fyfe G. C. Gobbi and J. S. Hartman Inorg. Chem. 1983 22 63. C,Si,Ge Sn Pb; N P As Sb Bi 97 unstable dialkenyltin( 11) compound.'03 Chemistry based on stannocene continues to prosper. Cowley'@' has demonstrated the dilithiation to 1,l '-dilithiostannocene which reacts with Me3SiCl and (Pr',N),PCI to give (60) and (61) respectively. The latter derivative was characterized by X-ray analysis. Reaction of pentamethylcyc- lopentadienyltin trifluoromethanesulphonate with B13 in dichloromethane results in tin-boron exchange and the formation of the (C,Me,)BI+ cation."' Related to stannocene is the unusual complex [(C,H,)Co( C2B2C)I2Sn (C2B2C= 4,5-diethyl- 1,3-dimethyl- 1,3-diborolenyl) prepared from the sandwich anion and tin(I1) chloride which has a 'tetradecker' structure bent at the central tin atom.lo6 The germanium tin and lead bis(trimethylsilyl)amides M[N(SiMe3),12 (M = Ge Sn or Pb) are 'V'-shaped monomers in both the gas phase and in the crystal (M = Sn or Pb) although the valence angle at the metal varies somewhat between the phases."' The tin bis( arenedithiolate) Sn( SC6H2B~t3-2,4,6)2 is also 'V-shaped but the tin( 11) and lead( 11) bis(2,6-di-isopropylbenzenethiolates)are trimeric with both bridging and terminal thiolate ligands and four-co-ordinated (central) and three-co-ordinated (terminal) metal atoms.lo* Dimeric [(Me SiO),Sn] has been obtained by the protolysis method from stannocene and trimethylsilanol in t~luene.'~' Veith' lo has described two more stannazane cage molecules Sn,( NBU~)~ and Sn,(NBu'),O.Molecules of the former are held together by van der Waal's forces whereas the latter forms dimers via weak intermolecular C + Sn interactions. The tin atoms in di-ammonium trichlorostannate chloride monohydrate form three short contacts to chlorine with a fourth much longer contact to the chloride anion. Neighbouring SnCl,. C1-units are connected by two longer Sn--Cl bridges forming a chain structure and completing a severely distorted octahedral environ- ment at tin. The anionic chains ammonium cations and the water molecule partici- pate in a three-dimensional hydrogen-bonded network."' The basic unit of the thiourea complex of tin(r1) chloride is the formula unit SnCI,(SC(NH2),} but are tightly bound into chains by both chlorine and sulphur bridging.Interchain N-H. -C1 hydrogen-bonding again results in a three-dimensional structure.' '' Lead-207 chemical shift data have been recorded for a number of bivalent lead compounds including lead( 11) nitrate acetate and perchlorate (all in water) lead(1x) pentafluorobenzoate (in thf) and two lead( 11) dithiophosphoridates (in CH2C12 and thf). In all cases only one signal was observed which in most cases was a consequence of the occurrence of equilibria which are rapid on the n.m.r. time scale. In these cases equilibrium constants were computed and in the case of lead(r1) acetate thermodynamic quantities were derived." Following the determination of the crystal I03 C.J. Cardin D. J. Cardin R. J. Norton H. W. Parge and K. W. Muir J. Chem. SOC. Dalton Trans. 1983 665. I04 A. H. Cowley J. G.Lasch N. C. Norman C. A. Stewart,andT. C. Wright Organometallics 1983,2 1691. 105 F. Kohl and P. Jutzi Angew. Chem. In!. Ed. Engl. 1983 22 56. I06 H. Wadepohl H. Pritzkow and W. Siebert Organornetallics 1983 2 1899. I07 T. Fjeldberg H. Hope M. F. Lappert P. P. Power and A. J. Thome J. Chem. SOC Chem. Commun. 1983 639. I08 P. B. Hitchcock M. F. Lappert B. J. Samways and E. L. Weinberg J. Chem. Soc. Chem. Commun. 1983 1492. 109 W. W. Du Mont and M. Grenz Z. Naturforsch. Teil B 38 1983 113. 110 M. Veith and 0. Recktenwald Z. Naturforsch.Teil B 38 1983 1054. Ill P. G. Harrison B. J. Haylett and T. J. King Inorg. Chim Act4 1983 75 265. P. G. Harrison B. J. Haylett and T. J. King Inorg. Chim. Acta 1983 75 259. 113 P. G. Harrison M. A. Healy and A. Steel J. Chem. SOC.,Dalton Trans. 1983 1845. 98 P. G. Harrison structure of a lead(r1)-EDTA complex last year formation constants in the Pb"- EDTA and Pb"-D-penicillamine systems have been determined.' l4 Adenosine 5'-triphosphate forms a complex of composition Pb2ATP-2H20 with lead( 11) acetate or nitrate in aqueous media. The complex is only sparingly soluble in water but the observation of two distinct 207Pb resonances indicates the presence of two different lead sites. Both this complex and the complex of lead(rr) acetate with dimethylphosphite decompose spontaneously in water or methanol the latter by stepwise elimination of methanol and acetic acid affording lead( 11) phosphite as the final product.' l5 The crystal structure of a hexalead chloride triorthoborate oxide Pb40{ Pb2( B03)3C1} can be regarded as being built up of [Pb,O]tetrahedra [Pb-Pb]dumbells isolated planar [BO,] groups and isolated chloride ions.' l6 Like the thallium compound T1Pb804Br9 Pb9O4Br1 also contains the [Pb804] group which may be considered as four [Pb40] tetrahedra which share common edges with each other.The central [Pb404] cube is reminiscent of the 'cubane' units in the [Pb,(OH);+] The lead atom in PbSO is in a distorted monocapped trigonal prismatic oxygen co-ordination closely related to PbS04.' '' SiMe P( Pr i2N)2 (-J (-J Sn &S'Me3 .-Tetravalent Derivatives.-As in recent years several novel organotin compounds have been synthesized and many characterized crystallographically.The addition of a stoicheiometric amount of Me,SnCl to the di-Grignard reagent BrMgCH2CH2CH2MgBr gave the cyclic oligomers (62)-(64) in ca. 70% yield. Only indirect evidence for the formation of 1,l '-dimethylstannacyclobutane could be obtained due to its high volatility and instability. Nevertheless 1,1,3,3-tetramethylstannacyclobutane could be isolated albeit in only 5% yield. ' l9 Similar Me \ fi/Me Mr:nT;e Me ('1,Me Me-Sn Sn-Me c: z:, S Me/'usn\Me L Me Me d Me7U''Me Me Me (62) (63) (64) I14 M. J. Willes and D. R. Williams Inorg.Chim. Acta 1983 80 L35. 'I5 P. G. Harrison and M. A. Healy Inorg. Chim. Acta 1983 80 279. I16 H. Behm Acta Crystullogr. 1983 C39 1317. 1 I7 H. L. Keller Angew. Chem. Int. Ed. Engl. 1983 22 324. 118 H. D. Lutz W. Buchmeier and B. Engelen Z. Natwrforsch. Teil B 1983 38 523. I19 J. W. F. L. Seetz G. Schat 0. S. Akkerman and F. Bickelhaupt J. Am. Chem. Soc. 1983 105 3336. 99 C Si Ge Sn Pb; N P As Sb Bi H Fe Fe techniques have been employed to prepare the large stannacycloalkanes (65) and (66).I2O The bridgehead carbon atom of tri-stanna-adamantane (67) is one of the most flattened methine carbon atoms known leading to an increased reactivity of the bridgehead hydrogen. 12' Treatment of 1,l'-dilithioferrocene-tetramethylethyl-enediamine with dibutyltin dichloride affords the doubly-bridged compound (68) (R = Bun).'22 Penta(methoxycarbony1)cyclopentadiene reacts with bistributyltin oxide to give the salt [Bu3 Sn(OH2),+][C5 (CO,Me),-] in which the tin has trigonal bipyramidal geometry with apical water d0n0rs.l~~ The use of sterically crowded organic groups usually produces compounds which are generally structurally quite different from the other more typical members.Thus syntheses involving 2,6-diethylphenylmag- nesium bromide result in the formation of hexakis(2,6-diethylphenyl)cyclotristan-noxane which has a planar [Sn,O,] ring rather than a more usual polymeric structure. Reduction of the corresponding diaryltin dichloride using lithium naphthaleneide gives hexakis(2,6-diethylphenyl)cyclotristannane the only example known to date.'24 Crystals of 1-methylstannatrane hexahydrate comprise trimeric units (69) in which the geometry around the central tin atom approximates closely a pentagonal bipyramid.The two crystallographically equivalent end tin atoms have distorted octahedral geometry. N.m.r. data suggest that the trimer unit is retained in ~olution.'~~ The carboxylato group in triphenyltin 2-hydroxy-5-methylazobenzoatechelates the tin atom in a distorted cis-SnC302 five-co-ordinated geometry. Unlike all other triorganotin carboxylates studied to date intermolecular association is completely absent.'26 N-(Trimethylstanny1)succinimide has a helical-associated polymeric I 20 M. Newcomb Y. Azuma and A. R.Courtney Organornetallics 1983 2 175. I21 A. L. Beauchamp S. Latour M. J. Olivier and J. D. Wuest J. Am. Chem. SOC.,1983 105 7778. 122 A. Clearfield C. J. Simmons H. P. Withers and D. Seyferth Inorg. Chim. Acfa 1983 75 139. I23 A. G. Davies J. P. Goddard M. B. Hursthouse and N. P. C. Walker J. Chem. SOC.,Chem. Commun. 1983 597. I24 S. Masamune L. R. Sita and D. J. Williams J. Am. Chem. SOC.,1983 105 630. I25 R. G. Swisher R. 0.Day and R. R. Holmes lnorg. Chern. 1983 22 3692. I26 P. G. Harrison K. Lambert and T. J. King J. Chem. SOC.,Dalfon Trans. 1983 363. P. G. Harrison structure with a trans-0 + Me,Sn-N geometry at tin.12' The triorganometal groups in triorgano-tin and -lead derivatives of N-acetylamino-acids are co-ordinated by unidentate carboxylic groups and the oxygen atom of the amidocarbonyl group.Co-ordination by NH groups does not occur.128 Reaction of chloro{2-(phenylazo)phenyl} mercury with tin metal leads to the formation of dichlorobis 2-(pheny1azo)phenyl tin in which the tin atom is six-co- ordinated in a very distorted fashion with two cis-chlorine and cis-nitrogen atoms in the equatorial plane and two carbon atoms of the ortho-metallated phenyl groups considerably displaced from the trans-axial position.129 Distorted octahedral co- ordination is also found in complexes of diorganotin dichloride with 1,2-bis(diphenylphosphory1)-ethaneand -ethylene (dppoe and dppoet respectively). In the structure of Bu2SnCl2.dppoe one oxygen atom is bonded more loosely than the other,',' whereas in the two complexes R2SnC12-dppoet when R = Bun the ligand chelates symmetrically but when R = Pr" the ligand is essentially uniden- In bis[bis(O,O'-diphenylthiophosphato)diphenyltin]hydroxide an inter-mediate in the hydrolysis of bis( O,O'-diphenylthiophosphato)diphenyltin the molecular units associate through double hydroxide bridges to form centrosymmetric dimers with a planar central [Sn20,] ring.The co-ordination at the tin atoms is best described as a badly distorted trigonal bi~yramid.',~ The phenylphosphonate and phenylarsonate derivatives Me2Sn( PhPO,) Me2 Sn( PhAsO,) and Bu2 Sn(PhAsO,) can be isolated in two modifications depending upon their method of preparation. The &modifications and the single modification of Ph2Sn(PhP03) appear to have infinite-chain structures whilst the a-modifications are suggested to have two- dimensional sheet structure^.'^^ The five-membered ring in Me2SnSCH2CH2S has an envelope conformation with a short intermolecular Sn...S contact completing a distorted trigonal bipyramidal geometry at tin.'34 127 F. E. Hahn T. S. Dory C. L. Barnes M. B. Hossain D. van der Helm and J. J. Zuckerman Organometallics 1983 2 969. G. Roge F. Huber H. Preut A. Silvestri and R. Barbieri J. Chem. SOC.,Dalton Trans. 1983 595. I29 J. L. Brianso X. Solans and J. Vicento J. Chem. Soc.. Dalton Trans. 1983. 169. 130 9. G. Harrison N. W. Sharpe C. Pelizzi G. Pelizzi and P. Tarasconi J. Chem. SOC.,Dalton Trans. 1983 921. 131 P. G. Harrison N. W. Sharpe C.Pelizzi G. Pelizzi and P. Tarasconi J. Chem. SOC.,Dalton Trans. 1983 1687. 132 F. A. K. Nasser M. B. Hossain D. van der Helm and J. J. Zuckerman fnorg. Chem. 1983 22 3107. 133 D. Cunningham P. Firtear K. C. Molloy and J. J. Zuckerman J. Chem. Soc. Dalton Trans. 1983 1523. I34 A. Secco and J. Trotter Actu Crysfallogr. 1983 C39 451. C Si,Ge Sn Pb; N P As Sb Bi 101 Several papers report the use of triorganostannyl-dithiocarboxylates and -thioamides as ligands towards transition metals. The esters Ph SnCS R replace ethylene in (PPh3) PtC2H4 to give the platinum complexes (PPh,) Pt(Ph3 SnCS R). Molecular structure studies of the complex with R = Me show that the ligand is bonded in an q2 fashion via the C=S group with the other sulphur being unco- ordinated.The initial products of the reaction with the thioamides Ph3 SnCSN' (N' = NMeH pyrrolyl) are also q2complexes but undergo an internal oxidative- addition to give the complexes (PPh,),Pt( Ph)(Ph,SnCSN') which contain a direct Pt-Sn bond.13' The lithium salt Ph3CS2Li reacts with pentacarbonyl-manganese and -rhenium bromides to afford the complexes Ph,SnCS,M(CO) (M = Mn or Re) which undergo thermal CO-substitution with phosphines and phosphite~.'~~,'~~ Tin-1 19 n.m.r. data for this type of complex and of the free ligands have been reported.'38 The complex cis-RCl,(CO)( PPh3) reacts with tin( 11) chloride dihydrate in acetone to yield solutions which are active in the catalytic hydroformulation of olefins. N.m.r. data show the solutions to contain the cationic complex trans-RCl(C0)- (PPh,),+ and four anionic complexes three of which have been identified as Pt( SnC13)s3- trans-PtC1( SnCl,),( PPh3)- and trans- PtC1( SnC13),(CO)-.Attempted isolation leads to further rearrangement reactions and only cis-PtC12(PPh3)2 could be isolated. The reaction is extremely solvent-dependent ligand rearrangement occurring in acetone and acetonitrile but in chloroform only simple insertion of SnC1 into one Pt-C1 bond is observed. Comparison of cis-PtC1,(L)(PR3) (L = CO SR2 or p-XC6H4NH2) with cis-PtCi2L2 and cis-PtCl,(PR,) shows that the former is the most active catalyst precursor in the presence of tin( 11) ~hloride.'~~-'~~ The tris(trimethylstanny1) group has been employed as a bulky ligand in the dimolyb- denum complex Mo2Sn( SnMe,) (NMe2)4.142 The first organosilylplumbane Pb( SiMe3)4 has been synthesized by the reaction of lead(11) chloride with Mg(SiMe,) in diethyl ether at -78 OC.14 5 Nitrogen The only reaction of any consequence that takes place in the equimolecular MaN03- KN03 system over the temperature range 500-600°C is the reaction:'@ NO3-NO2-+ )O Double-6 ab initio calculations on dinitrogen tetroxide are in excellent agreement with the experimentally determined structural pararneter~.'~' Molecules of dinitrogen pentoxide in the gas phase at -11 "C comprise two -NO2 groups joined by a fifth 135 A.W. Carr R. Colton D. Dakternieks B. F. Hoskins and R. J. Steen Inorg. Chem. 1983 22 3700, I36 T. Hattich and U. Kunze Z.Nuturforsche. Teil B 1983 38 655. 137 U. Kunze and T. Hattoch Chem. Ber. 1983 116 3071. B. Mathiasch and U. Kunze Inorg. Chim. Actu 1983 75 209. 139 G. K. Anderson H. C. Clark and J. A. Davies Inorg. Chem. 1983 22 427. I40 G. K. Anderson H. C. Clark and J. A. Davies Inorg. Chem. 1983 22 434. 141 G. K. Anderson C. Billard H. C. Clarke J. A. Davies and C. S. Wong Inorg. Chem. 1983 22 439. 14' M. J. Chetcuti M. H. Chisholm H. T. Chiu and J. C. Huffrnan J. Am. Chem. Soc. 1983 105 1060. I43 L. Rosch and U. Starke Angew. Chem. Int. Ed. Engl. 1983 22 557. 144 D. A. Nisseren and D. E. Meeker Inorg. Chem. 1983 22 716. 145 C. W. Bauschlicher A. Komornicki and B. Roos J. Am. Chem. SOC.,1983 105 745. 102 P. G. Harrison oxygen atom by non-collinear bonds.The -NO groups undergo large-amplitude torsional motion about a point of minimum energy corresponding to C symmetry for the molecule with the dihedral angles between these groups and the N-0-N plane each about 30°.146The structure of the gaseous H,NO2-ion in the negative chemical ionization mass spectrum of butyl nitrate is suggested to be the oxygen base HOHNO-and was confirmed by calculation at the 4-31 le~e1.l~' Hydrazoic acid in solution in nitric acid at 97 "C decomposes to form a mixture of NZ N20 and NO in a strongly acid-catalysed reaction. The proposed mechanism involves electrophilic attack by NO2+ on hydrazoic acid to form N,ONO which can then fragment to N + 2NO-or dissociate to N3. + N02-.148 The decomposition of nitroamine in concentrated aqueous perchloric sulphuric and hydrochloric acids proceeds by rate-determining nucleophilic attack of water upon the protonated nitroamine to give hydroxylamine and nitrous acid which then react to give dinitrogen Initially homogeneous solutions of hydroxylamine in nitric acid can react to form a two-layer system one a solution of nitrous acid in nitric acid and the other a solution of hydroxylamine in nitric acid.'" Definitive evidence that N20 arises from a symmetric precursor species in the hydroxylamine-nitrous acid reaction over the entire range pH 5-9 has been pre~ented.'~' High-resolution nitrogen n.m.r.spectra have been recorded for a number of fluoronitrogen cations in anhydrous HF solution. The lines in the linear or planar species N=NF+ NOF2+ and F2N=NF+ show .rr-fluoro effects being shifted upfield relative to those in corresponding species with hydrogen alkyl or aryl groups instead of fluorine despite the reduction in electron density on nitrogen.In non-planar species however the nitrogen line moves strongly downfield with fluorination as in NH4+to NH3F+to NF4+,and is described as a a-fluoro effect and is rationalized at least in part by a decrease in electron density on nitr~gen."~ Perfluoroalkyl-N,N-difluorohydroxylamines R,0NF2 have been synthesized by the reaction of per- fluoroalkyl hypofluorites with difluoramine in the presence of alkali metal fluoride^,'^^ and by the Lewis acid-catalysed addition of NF30 to 01efins.'~~ The unexpected directian of the NF,O addition resulting in exclusive formation of the anti-Markovnikov isomer can be rationalized by a stepwise addition of BF3 and NF30 via an RfBF2intermediate.The reaction of dichloramine with hypochlorous acid is general base catalysed the base assisting proton removal from NHC1 as the nitrogen attacks the chlorine of HOCl. The trichloramine formed reacts with dichloramine to generate more hypochlorous acid thus speeding up the decompo- sition. The electrochemical reduction of fluorenone triphenylphosphazine F1=NN=PPh3 in DMF-0.1 M-Bu4NC104is initially a one-electron process which I46 B. W. McClelland L. Hedberg K. Hedberg and K. Hagen J. Am. Cbem. SOC.,1983 105 3789. 147 M. M. Bursey R. L. Cerny L. G. Pedersen K. E. Gottschalk K. B. Torner and T.A. Lehrnan J. Cbem. SOC. Cbem. Commun. 1983 5 17. 14' B. M. Maya and G. Stedman J. Cbem. SOC.,Cbem. Commun.,1983 257. I49 M. N. Hughes J. R. Lusty and H. L. Wallis J. Cbem. SOC.,Cbem. Commun. 1983 261. 150 R. J. Gowland and G. Stedrnan J. Cbern. SOC.,Cbem. Commun. 1983 1038. ''I F. T. Bonner J. Kada and K. G. Phelan Inorg. Cbem. 1983 22 1389. 152 J. Mason and K. 0. Christe Inorg. Cbem. 1983 22 1849. I53 W. Maya D. Pilipovich M. G. Warner R. D. Wilson and K. 0.Christe Inorg. Chem. 1983 22 810. I54 R. D. Wilson W. Maya D. Pilipovich and K. 0. Christe Inorg. Cbem. 1983 22 1355. I55 V. C. Hand and D. W. Margerum Inorg. Chern. 1983 22 1449. C Si,Ge Sn,Pb; N P As Sb Bi 103 affords the corresponding radical anion F1=NN=PPh3T.This radical anion is unstable on the cyclic voltametric time-scale and decomposes by N-P bond fission to give PPh and the 9-diazofluorene anion radical F1N2T which then can react rapidly with either the starting material or itself to give a stable dimeric diar1i0n.l~~ The photolysis of CF,CF2N=NCF2CF3 with S2C12 at 0 "C affords the first example of a thiadiaziridine CF,CF2N-S-NCF2CF3 but only in 5% ~ie1d.l~' Poly(su1phur nitride) can be synthesized electrochemically in liquid SO2 from cyclopenta- azathenium chloride S5N5C1.15* 6 Phosphorus and Arsenic Probably the most exciting developments occurring in this area of chemistry involve compounds with multiple bonds. Syntheses of compounds containing P=P P=As P=Sb and As=As double bonds have been described.The method devised by ~owley'~~-'~~ employs DBU (1,5-diazabicyclo[5.4.O]undec-5-ene)as a dehy-drohalogenating agent between a silylmethyl Group V element dichloride (Me3Si)2CHMC12 (M = P As or Sb) and the 2,4,6-tri-t-butylphenylphosphine or arsine yielding the derivatives (70). The diaminodiphosphine (Bu'M~~S~),N-P=P-N(S~M~~BU~)~, was obtained by the reaction of (Bu'Me2Si),N-PC12 with either Bu'Li or lithium X-Ray crystallographic studies have been carried out on the latter compound and on the P=As and As=As homologues of (70). The P=P bond in the aminodiphosphine is similar to that in H M=M' But M=M'= PorAs \/ Me,Si-C M = PM' = As or Sb / Me,Si (70) previous examples whilst both the P=As and As=As bond distances are consistent with multiple-bond formation.Treatment of the diaryldiphosphene ArP= PAr (Ar = 2,4,6-But3C6H2) with elemental sulphur affords the monosulphide ArP(S)=PAr whose structure has been confirmed by X-ray analysis (P=P distance is only 0.2 longer than in ArP=PAr). The reaction is reversed by treatment with HMPTA but isomerization to the thiadiphosphirane ArP-S- PAr occurs both photochemically and thermall~.'~ Reaction of (Me3Si),P=P(SiMe3) with anhydrous HC1 gives (71) whereas excess HBF,.Et,O affords (Me,Si),CPH,BF,. In contrast complete P=P bond cleavage occurs when the diaryldiphosphene ArP=PAr is treated with HCl 156 D. E. Herbranson F. J. Theisen M. D. Hawley and R. N. McDonald J. Am. Chem. SOC.,1983,105,2544. I57 R. C. Kumar and J. M. Shreeve J.Chem. SOC. Chem. Commun. 1983 658. 158 A. J. Bannister Z. V. Hauptman and A. G. Kendrick J. Chem. SOC.,Chem. Commun. 1983 1016. 159 A. H. Cowley J:E. Kilduff S. K. Mehrotra N. C. Norman and M. Pakulski J. Ghem. Soc. Chem. Commun. 1983 528. 160 A. H. Cowley J. G. Lasch N. C. Norman M. Pakulski and B. R. Whittlesey J. Chem. SOC.,Chem. Commun. 1983 881. 161 A. H. Cowley J. G. Lasch N. C. Norman and M. Pakulski J. Am. Chem. SOC.,1983 105 5506. 162 E. Nieke R. Ruger M. Lysek S. Pohl and W. Schoeller Angew. Chem. Znt. Ed. Engl. 1983 22 486. 163 M. Yoshifuji K. Shibayama N. Inamoto K. Hirotsu and T. Higuchi J. Chem. SOC.,Chem. Commun. 1983. 862. P. G. Harrison and the cations (72) (initially) and (73) (on warming) are formed with HBF4.Et20.Ia Not surprisingly diphosphenes and diarsines have been employed as ligands towards transition metals.Unlike the complex (74) in which the 7r-electrons of the P=P double bond are donated to the only the n-electron pairs on phos- phorus are used in complexes (75),16' (76),166(77),167and (78).16' In the complex ' [Fe(CO),p-Fe(CO),](ArP=PAr) (Ar = 2,4,6-But3C6H20) the diphosphene func- tions in both ways simultaneously.168 The 7 '-diarsene-chromium complex (79) has also been chara~teri2ed.I~~ Similar complexes with diaminodiphosphene (80)and M = Fe; n = 4 M = Ni; n = 3 (77) CH(SiMe3)2 As=As / / I 2,4,6-But3C6H2 Cr(CO) (79) 164 A. H. Cowley J. E. Kilduff N. C. Norman M. Pakulski J. L. Atwood and W. E. Hunter J.Am. Chem. SOC.,1983 105 4845. 165 J. Borm L. Zsolnai and G. Hutner Angew. Chem. Znr. Ed. Engl. 1983 22 977. 166 K. M. Flynn N. M. Olmstead and P. P. Power J. Am. Gem. SOC.,1983 105 2085. I67 A. H. Cowley J. E. Kilduff J. G. Lasch N. C. Norman M. Pakulski F. Ando and T. C. Wright J. Am. Chem. SOC.,1983 105 7751. 168 K. M. Flynn H. Hope B. D. Murray M. M. Olmstead and P. P. Power J. Am. Chem. SOC.,1983 105 7750. 169 A. H. Cowley J. G. Lasch N. C. Norman and M. Pakulski Angew. Chem. Int. Ed. Engl. 1983.22,978. C Si Ge Sn Pb; N P As Sb Bi 105 (8l) aminophosphinine (82) and (83) aminoarsinidine (84) and (85),"' 'naked' phosphorus atoms (86),17*diphosphorus (:PEP:) (87),'72 and di-t-butylarsanediyl (88),'73ligands have been synthesized and in most cases characterized structurally.(CO),Fe N( SiMe,) N( SiMe,) N(SiMe,) \/ P=P P P=P / 6 I ".\ (Me3Si),N /L Fe(CO) (Me,Si)2N /L Cr(CO) (co),c~ ICr(CO) (80) (81) (82) Me,Si)2 N N(SiMe,) N(SiMe,) N( SiMe,) / I I P-Cr,( CO),=P As As .;i ';c / -A / -\ (C0)2Cr Cr(CO) (CO),Cr -%Cr(CO) (CO),Fe WCO) (83) (84) (85) /ML. P= But nP / (CO),co -Co(CO) M=As 1 .. \ L,M = (CO),Cr COCO But L,M = (CO),W L M = ( $-C,H,)M~I(CO)~ (88) (87) The major product from the reaction of ( Me3Si),CLi with (Me Si),CPCl,/ (2,4,6-t- Bu3C6H2)PC12 mixtures is the new phospha-alkene (89).'74 Phospha-alkenes and -alkynes exhibit different modes of bonding in the transition-metal complexes 7'-bonding is observed in the complexes (90) and (91),175 T2-bonding in the R CPh2 But \/ \CFP / I Me,Si Pt r;t Ph,C=P/ \P=CPh Ph,C=Pk \RP=CPh RR (91) (90) R = mesityl R Bu' \ Ph,C=P./ CH(SiMe,) Ph2 P '&\PPh Ph 2 P-9p" Me P / \P II I H2C\C/CH H2CyCH2 / Ni-c II /\ /\ Me CH,PPh Me CH,PPh Me,P \CH(SiMe,) (92) (93) (94) K. M. Flynn B. D. Murray M. M. Olmstead and P. P. Power J. Am. Chem. SOC.,1983 105 7460. H. Lang L. Zsolnai and G. Huttner Angew. Chem. Znt. Ed. Engl. 1983 22 976. H. Lang L. Zsolnai and G. Huttner Angew. Chem. Int. Ed. Engl. 1983 22 976. 170 171 172 173 M Luksza S. Himmel and W. Malisch Angew. Chem. Znt. Ed. Engl. 1983 22,416. 174 A. H. Cowley J. E. Kilduff M. Pakulski and C. A. Stewart J. Am. Chem.SOC.,1983 105 1655. I75 S. I. Al-Resayes S. I. Klein H. W. Kroto M. F. Meidine and J. F. Nixon J. Chem. SOC.,Gem. Commun. 1983 930. P. G. Harrison complexes (92) (93) and (94),'753'76 whilst an T2-bridging mode occurs in the complexes (95) and (96).'77 Ph-P=C P( Ph)SiMe / 0 \ N-R I SiMe (95) (96) (97) 1,3-Diphosphapropenes (97) are obtained from the reaction of phenyl- bis(trimethylsily1)phosphane with isocyanide dichlorides RN=CC12.17' The first stable phosphaketene has been synthesized according to the route shown in Scheme 22.'79Flash vacuum pyrolysis of the diphosphetanes (98) affords the (iminomethyl- idene)phosphines (99) (Scheme 23).'*' Treatment of (Me3Si),N-P=NSiMe3 with 0 Scheme 22 the sterically hindered lithium reagent 2,4,6-tri-t-butylphenyl-lithium and 2,2,6,6-tetramethylpiperidine hydrochloride leads to the formation of (loo) the first ther- mally stable example of a compound with the C-P=N skeleton.'8' R I P Ph-N=C /\,C=N-Ph 2R-p=C=N-ph P I R Scheme 23 Bu' BulQ P=N SiMe, Bu' ( 100) I76 A.H.Cowley R. A. Jones C. A. Stewart and A. 1. Stuart J. Am. Chem. SOC.,1983 105 3737. I77 G. Becker W. A. Henmann W. Kalcher G. W. Kriechbaum C. Pahl C. T. Wagner and M. L. Ziegler, Angew. Chem. Int. Ed. Engl. 1983 22 413. R. Appel P. Knoch B. Laubach and R. Severs Chem. Ber. 1983 116 1873. I79 R. Appel and W. Paulen Angew. Chem. Int. Ed. Engl. 1983 22 785. I80 C. Wentrup H. Briehl G. Becker G. Uhl H. J. Wessely A. Maquestiau and R.Flamman J. Am. Chem. SOC.,1983 105 7194. V. D. Romanenko A. V. Ruban and L. N. Markovski J. Chem. Soc. Chem. Commun. 1983 187. 107 C,Si Ge Sn Pb; N P As Sb Bi A few papers describing phosphorus ylide chemistry are worthy of note. Theoreti- cal studies for the phosphonium cyclopropylide H3 P=C(CH2)2 show that the ground-state equilibrium geometry has a pyramidal carbanion centre.lB2 The triethyl- amine-catalysed reaction of dimethylzinc with (CF,),PH gives high yields of the monomeric phosphorus(I1) ylide CF3P=CF2 which is stable as a gas at 100 "C or liquid at -78 OC.lS3 Amongst the crystal structure determinations are those of the ylides Ph,P=C( SPh)SePh,lB4 which has a planar [PCSSe] skeleton Ph P=C(CH2) ,IB5 in which the approximately tetrahedral onium centre is inclined to the neighbouring plane of the puckered cyclobutane ring Ph,P=C(PPh2)2,186 which again has a planar [P=CP2] skeleton and (Me2N)3P=C=P(NMe2)3,187 which is linear at the central carbon atom.The pyrolysis of the trialkyldibromo- arsorane (Me SiCH2),AsBr2 under reduced pressure yields the (bromomethyl)arsane (Me3 SiCH2)2AsCH2 Br via the intermediate formation of Br( Me SiCH2)2A~=CH2.188 The gas-phase ion-molecule chemistry of H2 P- studied by the flowing after-glow technique has shown that reaction with N20 C02,OCS CS2 02,NO2,SO2,MeX and Me3SiCl to yield a variety of ion-products arises from nucleophilic attack of H2P- on the neutral molecule followed by intramolecular proton transfer and/or expulsion of a neutral fragrnent.lB9 Phosphenium ions react with dienes to form the corresponding 3-phospholenium ions as the tetrachloraluminates (Scheme 24).190*191 Scheme 24 Tetraphenylfluorophosphorane can exist in at least three different forms including an ionic monomer a molecular monomer and a dimer.192 Low-temperature limiting 19 F and 31Pn.m.r. spectra suggest that the ground-state geometry of the fluxional phosphorane Me(CF3)3 PH has two axial CF groups on a trigonal-bipyramidal frarne~0rk.I~~ In spite of the steric crowding present in the silylmethylphosphine Ph,PC(SiMe,) readily forms phosphonium salts and also the ylide MePh P=C( SiMe3)2. Methanol cleaves trimethylsilyl groups successively but with decreasing ease giving finally Ph2MeP.194 M.A. Vincent H. F. Schaeffer A. Schier and H. Schmidbaur J. Am. Chem. SOC.,1983 105 3806. I83 A. B. Burg Inorg. Chem. 1983 22 2573. 184 H. Schmidbaur C. Zybill C. Kriiger and H. J. Kraus Chem. Ber. 1983 116 1955. H. Schmidbaur A. Schier and D. Neugebauer Chem. Ber. 1983 116 2173. 186 H. Schmidbaur U. Deschler and B. Milewski-Mahrla Chem. Ber. 1983 116 1393. I87 R. Appel U. Baummeister and F. Knoch Chem. Ber. 1983 116 2275. I88 A. Meyer A. Hartl and W. Malisch Chem Bet. 1983 116 348. I89 D. R. Anderson V. M. Bierbaum and C. H. Dehy J. Am. Chem SOC.,1983 105 4244. C. K. SooHoo and S. G. Baxter J. Am. Chem. SOC.,1983 105 7443. 191 A. H. Cowley R. A. Kemp J. G. Lasch N. C. Norman and C. A. Stewart J. Am. Chem. Soc. 1983 105 7444. 192 S.J. Brown and J. H. Clark J. Chem. SOC.,Chem Commun. 1983 1256. 1Y3 L. V. Griend and R. G. Cavell Inorg. Chem. 1983 22 1817. I94 C. Eaborn N. Retta and J. D. Smith J. Chem. Soc. Dalron Trans. 1983 905. 108 P. G. Harrison The adduct H3N.PF5 obtained either from the two components or (better) from HF and (F2P=N)3 has a slightly distorted octahedral geometry at phosphoru~.'~~ The structures of S(PF2)2 Se(PF,), and PF2(SMe) have all been determined in the gas phase by electron diffraction. For the latter three conformations fit the data equally well.'96 Phosphorus(m) acid reacts rapidly with S(PF2)2 to give PHO(OPF2)2 and then more slowly to give P(OPF2),. Reaction with diorganophosphites affords P(OR)2(OPF2) whilst phosphoric acid and other hydroxy-derivatives .of phos- The phorus(v) give difluoroph~sphino-esters.'~~~'~~reaction of bis(penta-methylcyclopentadieny1)fluoroarsine with BF3 affords the bis(pentamethylcyc1o- pentadieny1)arsenium cation which exists as an angular ~andwich.'~~ Tris(pheny1thio)arsine consists of discrete molecules with C3 symmetry.200 Numerous papers describe compounds containing direct phosphorus-phosphorus bonds.The reaction of Pri,NPC12 with magnesium metal in boiling thf gives either the diphosphine (101) or the cyclotetraphosphine (102) depending on the mole Pr' N NPr', \/ Pr' N NPr' P-P \/ I1 P-P c1/p-p\cl Pr' N ' 'NPr' (1011 (102) ratio of the reactants.20' The diphosphabutadiene (103) has been obtained via the routes shown in Scheme 25.202Unsymmetrical tetra-alkyldiphosphanes have been synthesized by the scrambling of the symmetrical diphosphanes in CH2C12.203 The eight-membered [P4C4] heterocycle (104) has been obtained in a one-step reaction II0"C /OSiMe3 Me3Si -P=C /OSiMe3 + C2C16 -c1 -P=C -Me SiCl \CMe -c2& 'CMe +150°CI-Me,SiCI OSiMe, I 0 (Me,Si),P-P(SiMe3)z + C1-C / ____* -2 Me3SiCI I \ CMe OSiMe (103) Scheme 25 I95 W.Storzer D. Schornburg G. V. Roschenthaler and R. Schmutzler Chem. Ber. 1983 116 367. 196 S. E. J. Arnold G. Gundersen D. W.H. Rankin and H. E. Robertson J. Chem. Soc. Dalton Trans. 1983 1989. I97 E. A. V. Ebsworth G. M. Hunter and D. W. H. Rankin J. Chem. SOC.,Dalton Trans. 1983 1983. I98 E. A. V. Ebsworth G. M. Hunter and D.W.H. Rankin J. Chem. SOC.,Dalton Trans. 1983 245. I99 P. Jutzi T. Wippermann C. Kriiger and H. J. Kraus Angew. Chem. Int. Ed. Engl. 1983 22 250. 200 G. C. Pappalardo R. Chakravorly K. J. Irgolic and E. A. Meyers Acra Crysrallogr. 1983 C39 1618. 201 P. B. King N. D. Sadanani and P. M. Sundaram J. Chem. Soc. Chem. Commun. 1983,477. *02 R. Appel V. Barth and F. Knoch Chem. Ber. 1983 116 938. 203 A. A. M. Ali and R. K. Harris J. Chem. Soc. Dalton Trans. 1983 583. C,Si Ge Sn Pb; N P As Sb Bi 109 from 3,4-dimethyl- 1-phenylphosphole and is a very flexible 'crown' ligand being able to adapt its shape to the stereochemical requirements of complexed metals.204 Three-membered rings containing P- P bonds have been prepared by various methods [P2S] rings have been prepared via the reaction of the diphosphene (Me3Si)2N-P=P-N(SiMe3)2 with elemental sulphdo5 or the reaction of mesityl- dichlorophosphine sulphide with magnesium and cyclotelluradiphos- phanes result from reaction of Bu'PC12 or (Bu'PCI) with Na2Te.A four-membered telluratriphosphacyclobutane results from the reaction of Bu'P( SiMe3)2 with ele- mental tell~rium.~~' Tris-t-butyldiphosphastibacyclopropaneis formed in the [2 + 13 cyclocondensation of KBu'P- PBu'K with BU~S~C~,.~~* The spirocycle ( 105) is formed similarly as a mixture of isomers but only in ca. 5% yield.209 The four- membered triphosphaetanones ( 106) readily eliminate CO on exposure to a reaction which is also exhibited by the five-membered tetraphosphaolan-5-one ( 107).,' The linear tetraphosphane Me,SiBu'P-(Bu'P),-PBu'SiMe, is remark- ably stable towards disproportionation and exists in only one conformation in Me MeMe Me 0 But Ph ,PBu' C $$-'k$ph Bu'P,ICI II \ P-P /But ' Bu'-P /\,P-Bu' Bu'P,1 ,PBu' s YI Bu'P' \PBu' P C I II PhMPh R 0 Me MeMe Me (1 05) ( 104) (107) (104) solution below -30 0C.212 The branched tetraphosphane P( Bu'PH), has been iso- lated ir pure form from the reduction of P(Bu'PBr)3 with LiAIH4.Because of the chirality of the Bu'PH groups the compound forms two diastereoisomers in a ratio of ca. 3 1 Pi-donors or acceptors exert a considerable effect on the bond lengths in substituted tetraphosphabicyclo[ 1.1.O]butanes ( 108). The central bond like bicyclo[ 1.1.O]butane possesses double bond character.,I4 P,Me3 has been shown by P{* H} n.m.r.to possess the 3,5,7-trimethyltricyclo[2.2.1.02*6]heptaphosphane structure ( 108) (two isomers).215 The different reactivity of the related cage compound ( 109) has been discussed in terms of a simple MO scheme.216 The triorganononaphos- phanes P9R3 (R = Pr' or Bu') have been synthesized by the reaction of (PriP)4 204 J. Fischer A. Mitschier F. Mathey and F. Mercier J. Chern. SOC. Dalton Trans.. 1983 841. 205 E. Niecke and R. Riiger Angew. Chem. lnt. Ed. Engi. 1983 22 155. 206 M. Yoshifuji K. Ando K. Shibayama N. Inamoto K. Hirotsu and T. Higuchi Angew. Chem. lnt. Ed. En& 1983 22 418. 207 W. W. Du Mont T. Severengiz and B. Meyer Angew. Chem. In?. Ed. EngL 1983 22 983.208 M. Baudler and S. Klautice 2. Nuturforsch. Ted B 1983 124. 209 M. Baudler and W. Leonhardt Angew. Chem. Int. Ed. Engl. 1983 22 632. 210 R. Appel and W. Paulen Chem. Ber. 1983 116 2371. 21 I R. Appel and W. Paulen Chem. Ber. 1983 116 109. 212 M. Baudler G. Reuschenbach and J. Yahn Chem. Ber. 1983 116 847. 213 M. Baudler J. Hellrnann and T. Schmidt Z. .Nuturforsch. Ted B 1983 38 537. 214 W. W. Schoeller and C. Lerch Inorg. Chem. 1983 22 2992. 215 M. Baudler and T. Pontzen 2.Nuturforsch. Teil B 1983 38 955. 216 R. Gleiter M. C. Bohm M. Eckert-Maksic W. Schafer M. Baudler Y. Aktalay G. Fritz and K. D. Hoppe Chem. Ber. 1983 116 2972. P. G. Harrison with PCl or the dehalogenation of a mixture of Bu'PCl and PCl with magnesium metal respectively.For the preparation of the methyl and ethyl homologues the latter reaction may be modified by employing organylcyclophosphanes instead of RPCl,. According to 31P n.m.r. data the nonaphosphanes possess a skeleton analogous to that of deltadecane (110).2'7 The thermolysis of hepta- and nona- phosphanes leads to the formation of P,,Pr' and PI3Pris the latter of which was proposed to have structure (1 1 1) on the basis of n.m.r. data.218 The largest phosphorus cage obtained is the hexadecaphosphide dianion (1 12) (as its lithium salt and octa-thf solvate) from the reaction of white phosphorus with lithum dihydrogenphosphide in boiling thf.219 Me dP\ 'p P \P-P ye/ 'P' Gas phase pyrolysis of the cyclic phosphonite (1 13) generates the monomeric metaphosphonite (1 14) which is trapped by an intramolecular reaction with the adjacent biphenyl group to afford (1 15).220 The mixed-ligand phosphorane ( 116) represents the least distorted example of rectangular pyramidal geometry so far examined being 93-0% displaced from trigonal bipyramidal.221 The reaction of C02 with Me(CF3)3 PNMe yields the neutral six-co-ordinated carbamate Me(CF3)3P0,CNMe2.In solution the CF groups are equivalent but at low tem- peratures the compound exists in the solid-state form.222 217 M. Baudler Y. Aktalay K. Kazmierczak and J. Hahn 2.Naturforsch. Teil B 1983 38 428. 218 M. Baudler Y. Aktalay V. Arndt K. F. Tebber and M. Feher Angew. Chem. Znt. Ed. Engl. 1983 22 1002. 219 M.Baudler and 0. Exner Chem. Ber. 1983 116 1268. 220 S. Bracher J. I. G. Cadogan 1. Gosney and S. Yaslak J. Chem. Soc. Chem. Commun. 1983 857. 22 I A .C. Sau J. M. Holmes R. 0.Day and R. R. Holmes Inorg. Chem. 1983 22 1771. 222 R. G. Cavell and L. V. Griend Inorg. Chem. 1983 22 2066. C Si Ge Sn Pb; N P As Sb Bi C1 (116) Reaction of (Pr',N),P(O)H with Mo(CO) proceeds via deamination and the formation of the complex (P~',NPO),MO~(CO)~, which contains a central [P404M02] cage structure.223 Both P4S3 and P,Se3 have been used as ligands in such complexes as {Ir(P4S3)(PPh3)C1(CO)}~z~4 and (np3)M(P4X3) (M = Ni X = S or Se; M = Pd X = S; np = tris{2-(diphenylphosphino)ethyl}amine).22' In the reac- tion of P4S3 and P4Se3 with [RhCl(cod)] in the presence of triphos {l,l,l- tris(diphenylphosphinomethyl)ethane} cleavage of the cage takes place and the complexes [(triphos)~h(~,~,)1.~,~, (X= s or Se) are isolated.226 The chemistry of P-N bonded compounds is extremely rich.The silylaminophos- phines (Me3Si),NPRPr' (Me3Si)*NPRH and [(Me3Si),NJ2PCHZR have been obtained by the Grignard method from the appropriate chlorophosphine. The P-H phosphines appear to be formed by a process in which the Grignard reagent functions as a reducing agent with the elimination of propene. Alternatively they can be prepared by reduction with LiAlH,. Treatment of the [(Me3Si),N],PCH2R deriva- tives with Me3SiN affords the phosphinimine [( Me,Si),N],PMe~NSiMe,. Similar phosphinimines can also be obtained by the reaction of the phosphonium salts [(Me Si) N],PMe2+I- with alkyl-lithium reagents.With CCl, the [( Me,Si) N],PCH,R compounds gave a mixture of (Me3Si),NPCl( Me,SiCHR)=NSiMe and (Me3Si),NPC1( CH,R)=NSiMe,. The reaction of CC14 with the sterically-congested mesityl derivative (Me3Si),NPRCHzSiMe3 (R = mesityl) unexpectedly afforded the four-membered [P,N,]ring compound (1 17) which on heating under a dynamic vacuum dissociates to the monomeric three-co-ordinated iminomethylenephosphorane( 118). This com- pound (1 18)is stable at room temperature for a short time but reverts to (1 17) after a few days.229 Papers describing P-N rings and cages abound. (5,10,15,20-Tetraphenylpor-phinato)dichlorophosphorus(v) chloride has been synthesized and its electro- 223 E.H.Wong M. M. Turnbull E. J. Gabe F. L. Lee and Y. Le Page J. Chem. SOC.,Chem. Commun. 1983 776. 224 C. A. Ghilardi S. Midollini and A. Orlandini Angew. Chem. Znt. Ed. Engl. 1983 22 790. 225 M.Di Vaira M. Peruzzini and P. Stoppioni Znorg. Chem. 1983 22 2196. 226 M.Di Vaira M.Peruzzini and P. Stoppioni J. Chem. SOC.,Chem. Commun. 1983 903. 227 H. R. O'Neal and R. H. Neilson Znorg. Chem. 1983 22 814. 228 B. L. Li J. S. Engenito R. H. Neilson and P. Wisian-Neilson Inorg. Chem. 1983 22 576. 229 2. M. Xie and R. H.Neilson Orgonometallics 1983 2 1406. P. G. Harrison R Me (1 17) (1 18) chemistry reveals that it undergoes two reductive processes at the porphorin ring.230 The structure of the related (porphinato)phosphorus( v) hydroxide dihydrate shows a distorted octahedral co-ordination for phosphorus which is displaced 0.09 8 from the mean plane of the pyrrole nitrogen atoms and a non-planar porphyrin ring.231 The concentration dependence of the 31P n.m.r.chemical shift of cyclenphosphine oxide (1 19) indicates that a monomer-dimer equilibrium is operating in CDC13 solution.232 Cyclenphosphorane ( 120) readily adds two equivalents of BH3 to afford the bis-adduct ( 121).233 (1 19) (1 20) (121) The cyclophosph(~rr)azanes (CIPNEt), C12P4(NEt), and C12P-NEt-PC12 are formed by suitable variation of the stoicheiometry of a mixture of PCl and ethyl- amine hydrochloride in refluxing sym-tetrachloroethane. 0x0 derivatives are also formed in low yields or by reaction with oxygen or DMS0.234In contrast to the reaction of propenyl-lithium with (N3P3F6) no evidence for degradation reac- tions uia anionic attack on the alkene centre was observed in the reaction of ( 1-1ithioalkoxy)ethylenes.Rather reaction proceeds smoothly to yield N3P3F,- [C(OR)=CH2] (n = 1 or 2) derivative^.^^' Similarly the reactions of enolate anions of acetaldehyde acetone and acetophenone lead exclusively to enol-substituted phosph( ~~~)azenes.*’~’~~’ Reaction of (P3 N3 Cl,) with methyl-lithium leads to the formation of acyclic ‘ring-opened’ phosphazenes and only small amounts of monomethyl- and dimethyl-substituted cyclotriph~sphazenes.~~~ Hexaphenoxy-cyclo(triphosphazene) polymerizes in the ion source of a mass spectrometer.239 The two arsazenes [(CF,),AsN] (n = 3 or 4) are produced by refluxing [(CF,),AS(C~)(S~M~,>]~ in n-hexane or n-heptane.The molecular symmetry of the tetra-arsazene approximates to 4.240 230 C. A. Marrese and C. J. Carrano Inorg. Chem. 1983 22 1858. 23 1 S. Mangani E. F. Meyer D. L. Cullen M. Tsutsui and C. J. Carrano Inorg. Chem. 1983 22 400. 232 J. E. Richman and J. J. Kubale J. Am. Chem. SOC.,1983 105 749. 233 J. M. Dupart S. Pace and J. G. Riess J. Am. Chem. SOC.,1983 105 1051. 234 D. A. Harvey R. Keat and D. G. Rycroft J. Chem. SOC.,Dalton Trans. 1983 425. 235 C. W. Allen and R. P. Bright Inorg. Chem. 1983 22 1291. 236 K. Ramachandran and C. W. Allen Inorg. Chem. 1983 22 1445. 237 P. J. Harris M. A. Schwalke V. Liu and B. L.Fisher Inorg. Chem. 1983 22 1812. 238 P. J. Harris and C. L. Fadeley Inorg. Chem. 1983 22 561. 239 M. Gleria G. Audisio P. Traldi S. Daolio and E. Vecchi J. Chem. SOC.,Chem. Commun. 1983 1380. 240 R. Bohra H. W. Roesky J. Lucas M. Noltemeyer and G. M. Sheldrick .I.Chem. SOC.,Dalton Trans. 1983 1011. C Si Ge Sn Pb; N P As Sb Bi 113 Related to the phosphazenes are P-N-S heterocycles such as (122) formed by the reaction of (Ph2PN),NSCl with Ph3Sb in acetonitrile?’ (123) formed by the thermal conversion of (122) at 150-185 0C,242 and (Ph2PN)2NSI which contains a six-membered [P2SN3] ring,243 as well as the complex (124).244 Other ring-systems studied include the azadiphosphirane (125),245and the azatriphosphetidines (126),245 the 1,3,2-diazaphosphetidin-4-0ne(127),246 the 1,3,2,4-diazadiaphosphetidin-2-oxide (128),246 the 1,2,4,3-thiadiazaphosphetidine-l,l-dioxide(129),246 and spiro systems such as (130),247(131),247 and (132).248 \ Me R R2 I I I N R~-P-NR’ R2-P-p=NR’ /\ 0% /N\ \/ II o=C /P-NEt /p\ /P-NEt2 R2’ P*NR1 R ‘N=P-NR l N Y 1 I R2 Me R 7 Antimony and Bismuth Three papers have reported the synthesis and properties of tetraorganodibismuthines R2Bi-BiR,.The general method is to generate the diorganobismuth sodium inter- mediate which is then treated with 1,2-dichloro- or 1,2-dibromo-ethane all in liquid ammonia. The dibismuthines are red in solution and most are red in the neat liquid or solid. However the tetramethyl- and tetra-iso-butenyl-dibismuthines and (133) 24 1 T.Chivers M. N. S. Rao and J. F. Richardson J. Chem. Soc. Chem. Commun. 1983 186. 242 T. Chivers M. N. S. Rao and J. F. Richardson J. Chem. SOC.,Chem. Commun. 1983 702. 243 T. Chivers M. N. S. Rao and J. F. Richardson J. Chem. SOC.,Chem. Commun. 1983 700. 244 0.J. Scherer J. Kerth and M. L. Ziegler Angew. Chem. Znr. Ed. Engl. 1983 22 503. 245 E. Niecke R. Riiger B. Krebs and M. Dartmann Angew. Chem. Znt. Ed. Engl. 1983 22 552. 246 E. Fluck and H. Richter Chem Ber. 1983 116 610. 247 A. Schmidpeter M. Mayibi P. Mayer and H. Tautz Chem. Ber. 116 1983 1468. 248 R. 0.Day A. Schmidpeter and R. R. Holmes Inorg. Chem. 1983 22 3696. 114 P. G. Harrison freeze to blue solids. The structure of tetraphenyldibismuthine has been deter- mined.249-25 1 Several new vinyldistibanes have been prepared by largely similar methods.These compounds also exhibit thermochromism existing as yellow liquid- phases but freezing as either yellow orange or violet solids.252 Tetramethyldistibane reacts with equimolecular amounts of di-p-tolylditelluride to afford the first Te-Sb bonded compound MeC,H,Te-SbMe .253 The structure of the complex (C,H,)Fe(CO)( PMe3)SbBr2.PMe3 has been determined.254 The main interest in antimony and bismuth halide chemistry lies with several structural determinations although U.V. photoelectron spectra for SbF and the bismuth trihalides,,, and the 35Cl and 121*123Sb n.q.r. frequencies for a number of adducts of antimony(v) chloride have been reported.256 In the solid chain structures are extremely common and are formed by halogen bridging which can be weak or strong.Such chain structures are found in the antimony fluoride [SbF3]3[SbF5],257 and in [IBr2][Sb2F [1Br0.75C10.251[SbC161~58 [Et NH][SbC1,],259 [MeNH3]3[SbC16],259 [Ph3SbC12][SbC13],260 [Ph3SbC1][SbC16],260 and the 4,4’-bipyridyl complex of SbC15 Alternatively as in the 2,2’-bipyridyl complex of SbC15,261 and the compounds A12Sb2112262 halogen and [(C5H5)2Fe]4[Bi4Br,6],z63 bridging produces small cluster species. Of the related complexes of BiCl, BiC13 (pptu) (pptu = 1-phenyl-3-( 2-pyridyl)-2-thiourea} and [BiC13 (deimdt),] (deimdt = N,N’-diethylimidazolidine-2-thione), the former is monomeric whilst the latter is a chlorine-bridged dimer.264 Similarly the structures of several oxide and oxy-acid derivatives have been determined.[SbO,] octahedra are present in monoclinic AsSbO ,265 HSb305,266 and the compounds MSb,0,3 (M = H30 Na or K).267 Octahedral co-ordination for 24Y A. J. Ashe E. G. Ludwig and J. Oleksyszyn Organometallics 1983 2 1859. 250 H. J. Breunig and D. Muller 2. Naturforsch. Ted B 1983 38 125. 25’ F. Calderazzo A. Morvillo G. Pelizzi and R. Poli J. Chem. Commun. 1983 507. 252 A. J. Ashe E. G. Ludwig and H. Pommerening Organometallics 1983 2 1573. 253 W. W. Du Mont T. Severengiz and A. J. Breunig Z. Naturforsch. Teil B,38 1983 1306. 254 H. A. Kaul D. Greissinger W. Malisch H. 0. Klein and U. Thewalt Angew. Chem. ~ni.Ed. Engl. 1983 22 60. 255 I. Hovak and A. W.Potts J. Chem. SOC.,Dalton Trans. 1983 635. 256 J. Rupp-Bensadon and E. A. C. Lucken J. Chem. SOC.,Dalton Trans. 1983 19. 257 W. A. S. Nandana J. Passmore D. C. N.Swindells P. Taylor P. S. White and J. E. Vekris J. Chem. SOC.,Dalton Trans. 1983 619. 258 T. Birchall and R. D. Myers Inorg. Chem. 1983 22 1751. 259 U. Ensinger W. Schwarz and A. Schmidt Z. Naturforsch. Teil B,1983 38 149. 260 M. Hall and D. B. Sowerby J. Chem. SOC.,Dalton Trans. 1983 1095. 26’ A. Lipka Z. Naturforsch. Teil B 1983 38 1615. 262 S. Pohl Z. Naturforsch. Teil B 1983 38 1539. 263 A. L. Rheingold A. D. Uhler and A. G. Landers Inorg. Chem. 22 1983 3255. 264 L. P. Battaglia and A. B. Corradi J. Chem. SOC.,Dalton Trans. 1983 2425. 265 D. Bodenstein A. Brehm P.G. Jones E. Schwarzmann and G. M. Sheldrick Z. Naturforsch. Teil B 1983 38 901. 266 G. Jager P. G. Jones G. M. Sheldrick and E. Schwarzmann 2. Naturforsch. Teil B,1983 38 698. 267 D. Bodenstein W. Clegg G. Jager P. G. Jones H. Rumpel E. Schwarzmann and G. M. Sheldrick Z. Narurforsch. Teil B 1983 38 1972. C Si Ge Sn Pb; N P As Sb Bi antimony is also found in [Me2P02SbC1]:68 and the Me4Sb ~xinate,*~~ whilst in the sulphate (H30)2Sb2(S04):70 and the phosphates Na(SbF)P04. n H20 and NH4 (SbF) P04.H20,27 the antimony enjoys square pyramidal co-ordination with * the lone pair of electrons occupying the sixth octahedral site. The structure of Bi604(OH)4(C104)6.7H20 contains discrete hexanuclear [Bi604(0H):+] clusters in which the six bismuth atoms have a slightly distorted octahedral arrangement.The co-ordination of each bismuth is basically pseudo-trigonal bipyramidal with the lone pair occupying an equatorial site. However four further contacts to oxygen result in an irregular eight-fold co-ordination polyhedron.272 Antimony is in six-fold co-ordination in the two dithiophosporidate derivatives Sb[S,P(OR),] (R = Me and Pri)273 and the xanthate Sb(SzCOEt)2Br,274 where bromine bridging gives rise to a chain structure. The stereochemistry at bismuth in the [Bi( S2C2(CN),),-] anion an infinite polymeric chain has been described either as a highly distorted octahedron with a stereochemically inactive lone pair or more likely a distorted pentagonal bipyramid in which the lone pair is stereochemically active in an equatorial 2h8 S.Blosl W. Schwarr and A. Schmidt Z. Naturforsch. Teil E 1983 38 143. 269 H. Schmidbaur B. Milewski-Mahrla and F. E. Wagner Z. Naturforsch. Teil B 1983 38 1477. 270 R. Mercier J. Douglade P. G. Jones and G. M. Sheldrick Acta Crystallogr. 1983 C39,145. 27 1 R. Mattes and K. Holz Angew. Chem. Int. Ed. EngL 1983 22 872. 272 B. Sundvall Inorg. Chem. 1983 22 1986. 273 D. B. Sowerby I. Haiduc A. Barbul-Rusu and M. Salajan Inorg. Chim. Acta 1983 68 87. 274 R. W. Gable B. F. Hoskins R. J. Steen E. R. T. Tiekink and G. Winter Inorg. Chim. Acta 1983 74 15. 275 G. Hunter and T. J. R. Weakley J. Chem. Soc. Dalton Trans. 1983 1067.

ISSN:0260-1818    

DOI:10.1039/IC9838000077

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

0,S Se Te By F. J. BERRY Department of Chemistry University of Birmingham P.0. Box 363 Birmingham B 15277 1 Introduction Several studies of similar compounds differing in the nature of the Group VI element which illustrate the influence of different chalcogen atoms on chemical and physical properties have been reported. For example a study' of the effect of the chalcogen atom on the magnetic and electrical prqperties of the hexagonal plutonium oxide chalcogenides of composition PuzOzX (X = 0 S or Se) has shed light on the structural and bonding properties of these materials. Other investigations have considered binary compounds differing in the nature of the chalcogen atom and have focused attention on the common structural properties of the solids. For example the indium(1Ir) chalcogenide semiconductors of composition In-2,0,X3 (X = S Se or Te) have been studied' by single crystal X-ray diffraction and found to possess similar structural features which interestingly involve the accommodation of some indium(1).Solid-state vibrational- and 35Cl nuclear quadrupole resonance-spectroscopic studies3 of some trichlorochalcogen tetrachloroaurates of the type [XC13][AuC14] (X = S Se or Te) are illustrative of other approaches to a series of compounds differing in the nature of the Group VI element. Analysis of spectra from the isomorphous [SCI3][AuCI4] and [SeCl,][AuCl,] compounds indicated the AuCI,- ion to be considerably distorted from D4,,symmetry. The X-ray powder diffraction patterns showed that [TeCI,][AuCI,] adopted a different structure with the n.q.r.and vibrational spectra indicating less distortion of the AuC1,- ion. The origins of the distortions in these compounds were considered in terms of secondary bonding interactions. It is also interesting to note the reaction of WC1,X (X = 0 S or Se) with triphenylphosphine which has been shown4 to lead to abstraction of the chalcogen atom the reduction of tungsten(v1) to tungsten(Iv) and the formation of WCI42PPh3. 2 Oxygen The first observation5 of a chemisorbed dioxygen species at the surface of a pure single crystal of silver at room temperature and low pressure is interesting because ' J. M. Costantini D. Damien C. H. de Novion A. Blake A. Cousson H. Abazli and M. Pages J. Solid State Chem.1983 47 210 ' C. Svensson and J. Albertsson J. Solid Slate Chem. 1983 46 46. A. Finch P. N. Gates T. H. Page and K. B. Dillon J. Chem. SOC.,Dalton Trans. 1983 1837. M. G. B. Drew E. M. Page and D. A. Rice J. Chem. Soc. Dalton Trans. 1983 61. R. B. Grant and R. M. Lambert J. Chem. SOC.,Chem. Comrnun. 1983 58. 117 118 F. J. Berry of the importance of silver as a catalyst for the heterogeneous selective oxidation of ethylene to ethylene oxide. The concentration of the adsorbed species was found to be relatively insensitive to surface structure and shown to be some 800-times higher than that inferred from e.s.r. studies of powders. Given the doubt which has previously been associated with the nature of the epoxidating species during the silver-catalysed heterogeneous oxidation of ethylene it is also interesting to record the results of a subsequent study, which showed that the stable dioxygen species chemisorbed on the clean silver crystal surface had no role in the epoxidation reaction and that chemisorbed atomic oxygen and the presence of subsurface oxygen were more likely to be necessary for the catalytic epoxidation of ethylene by silver.The historical interest in the aqueous chemistry of the superoxide radical anion has many origins including its role in biological processes and it is therefore pertinent to record a new and convenient route' to the formation of the superoxide ion in aqueous solution. It is also interesting to note the first reported* example of oxygen atom transfer by a p-0x0-Fe"' oligomer during the oxidation of triphenylphosphine by p-0x0-bis[phthalocyaninatoiron( III)] and the thermo-dynamic studies' of the addition of molecular oxygen to cobalt(I1) complexes in the cobalt(r1)-ethylenediamine-oxygen system in aqueous solution at 25 "C.3 Sulphur A valuable review has appeared" of thio- and seleno-compounds of main-group elements which illustrates how during the last decade modern preparative tech- niques and methods of structural investigation have led to the formation of novel and often unexpected oligomeric and polymeric compounds containing both sulphur and a main-group element. The review draws attention to notable features of bonding structure and reactivities of these types of compounds and describes new develop- ments in the properties and uses of materials such as the boron sulphides and ion-conducting air-stable thioborates ;the molecular polynuclear thio- and seleno- anions of Ga In Si Ge and Sn; the application of new polynuclear sulphide- and selenide-halides of Si and Ge as reagents for inorganic and organic reactions; the synthesis of argyrodite (Ag,GeS,)-like phases with remarkable solid-state properties ; and the characterization of S-H .S type hydrogen bridges which are relevant to an improved understanding of certain interactions in sulphur-containing bio- molecules. Several of these topics have shown themselves to be central themes in the current interest in sulphur-containing compounds. For example the B,S 16 macrocycle (1) has continued to provoke interest especially in respect of its isostruc- tural although not isoelectronic relationship with porphine (2) (Figure 1).Although no complexes have been reported for B8S,6,porphyrins are known to form a wide variety of complexes with both transition metals and simple metal ions. It is therefore interesting to note the recent usell of extended Huckel calculations to compare the valence electronic structures of B,S, and porphine and their Cu2+ complexes and R. B. Grant and R. M. Lambert J. Chem. SOC.,Chem. Commun. 1983 662. ' M. S. McDowell A. Bakac and J. H. Espenson Inorg. Chem. 1983 22 847. C. Ercolani M. Gardini G. Pennesi and G. Rossi J. Chem. SOC.,Chem. Commun. 1983 549. S. Cabani N. Ceccanti and G. Conti J. Chem. SOC.,Dalton Trans. 1983 1247.I" B. Krebs Angew. Chem. Inr. Ed. Engl. 1983 22 113. I' B. M. Gimarc and J. K. Zhu. Inorg Chem.. 1983 22 479. 0,S Se Te 119 S/ \ S (1) (2) Figure 1 Schematic representation of the B,S, macrocycle (1) and porphine (2) (Reproduced by permission from Inorg. Chem. 1983 22 479) which have indicated that the stability of the B8S,6and porphine complexes are comparable. Compounds containing sulphur and other main-group elements have also received attention. Amongst these the sulphur-nitrogen compounds have continued to attract significant interest. For example the synthesis of the quasi-one-dimensional polymer poly(su1phur nitride) with metallic properties has been achievedI2 electrochemically in liquid sulphur dioxide from cyclopentazathienium chloride S,NSCI which itself was prepared by a new method from S5N,FeC14 and CsF.The structure of the six-membered ring of tetrasulphur dinitride S4N2,has been predi~ted'~ by extended Huckel calculations to adopt a half-chair conformation and to be consistent with the X-ray crystallographic analysis. The structures of other six-membered ring-type species such as SqN:+ S4N;- S3N3-,S3N3+,S6 and S,'+ have also been briefly considered14 and the synthesis of several new five- and six-membered saturated heterocycles containing sulphur-nitrogen bonds reported. l4 An interesting structural study of the silver( I) complex tetrakis(tetrasu1phur tetranitrogen dioxide)silver hexafluoroarsenate(v) [Ag(S4N402)4]+[A~F]-,has shown" the silver atoms to lie below a square of four nitrogen atoms with the bisdisphenoidal (triangulated dodecahedral) co-ordination of silver being completed by two intramolecular Ag-0 contacts and intermolecular Ag-N and Ag-0 interactions.The structure shows the tetrasulphur tetranitrogen dioxide ligands to be approximately planar (except for the SOzunits) with only the nitrogen and oxygen atoms attached to S"' interacting with the silver atom and thereby causing minimum disruption to the delocalized bonding in the rest of the ring (Figure 2). The reactions of tetrasulphur tetranitride have also received attention. For example tetrasulphur tetranitride has been found" to react with excess VCI in I' A. J. Banister 2. V. Hauptman and A. G. Kendrick J. Chem. Soc. Dalton Trans. 1983 1016.l3 J. K. Zhu and B. M. Gimarc Inorg. Chem. 1983 22 1996. l4 A. H. Cowley S. K. Mehrotra and H. W. Roesky Inorg. Chem. 1983 22 2095. l5 H. W. Roesky M. Thomas H. G. Schmidt W. Clegg M. Noltemeyer and G. M. Sheldrick J. Chem. SOC.,Dalton Trans. 1983 405. l6 H. W. Roesky J. Anhaus H. C. Schmidt C. M. Sheldrick and M. Noltemeyer J. Chem. SOC.,Dalton Tram. 1983 1207. 120 F. J. Berry Figure 2 The structure of the [Ag(S,N402)4]+ cation showing 50% thermal ellipsoids and the atomic numbering scheme (Reproduced from J. Chem. SOC., Dalton Trans. 1983 405) CH2C12 to form a mixture of VC12(S2N3) and S2N2VCI4 whereas the reaction with excess TiCI4 gives only S4N4TiCI,. The crystal structure of VCI2(S2N3) was found to consist of chlorine-bridged dimers linked by additional weak V- N interactions to form polymeric chains.The six-membered VNSNSN ring was shown to be effectively planar. In another study,17 31P n.m.r. was used to monitor the reactions of tetrasulphur tetranitride with tetraphenyl- and tetramethyl-diphosphine and diphenylphosphine in toluene under reflux. In addition to the six-membered R2PS2N3 ring which has been reported previously and the cyclophosphazenes (R2PN)3,4 two structural isomers of the eight-membered ring R,P2S2N4 were formed. The crystal structure of 1,5-Ph2P( NSN)2PPh2 was found to consist of a folded eight-membered ring with a cross-ring S-S contact. The 1 ,3-(Ph2PNPPh2)S2N3 compound also contained an eight-membered ring with phosphorus atoms in the 1,3-positions.The NSNSN unit was shown to be essentially planar with the phosphorus atoms being ” N. Burford T. Chivers. and J. F. Richardson. Inorg. Chem. 1983 22. 1482. 0,S Se Te 121 out and on opposite sides of the plane. The electronic structure of 1,3-(Ph2PNPPh2)S2N3was compared with that of Ph2PS2N3 using the HMO approach and the strong visible absorption band at ca. 460 nm tentatively assigned to the HOMO (T*)-+ LUMO (T*)transition of a 10 n-electron manifold. Compounds containing sulphur phosphorus and nitrogen have been the subject of other investigations. For example the reaction of (PhzPN),NSC1 with KI in acetonitrile reportedly produces*8 (Ph2PN)2NSI which has been shown by X-ray crystallography to be an inorganic heterocycle composed of a six-membered P2SN3 ring with an exocyclic sulphur-iodine bond.The structure (Figure 3) shows the five-atom NPNPN unit to be planar to within 0.05 % and the sulphur atom to lie about 0.29 8,out of this plane. The conformation and the endocyclic bond lengths and bond angles of the six-membered P2SN3 ring are similar to those found in the corresponding chloride (Ph,PN),NSCI. The exocyclic sulphur-iodine bond [S-I 2.713(3) A] which is said to have significant ionic character is an interesting feature of the structure. The compound was found to decompose at ca. 150 "C to give Ph8P,N6S which is a spirocyclic compound in which two almost planar six-membered P2SN3 rings are fused at a common approximately tetrahedrally co-ordinated sulphur atom (Figure 4).Each of the six-membered rings is formally associated with six n-electrons (assuming sulphur contributes one n-electron to each ring) and this may account for the high thermal stability of (Ph2PN),N2S which is the final product of many thermal transformations involving PNS heterocycles. In a subsequent study'' the formation of a twelve-membered P4S2N6 ring as an intermediate during the thermal conversion of (Ph2PN),NSNMeZ,a P2SN3 C C C Figure 3 The structure of (Ph,PN),NSI showing 50% probability ellipsoids and the atomic numbering scheme. For clarity onl-v the a-carbon atoms of the phenyl rings are shown (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 700) T. Chivers M. N. Sudheendra Rao and J. F. Richardson J. Chem. Soc. Chem. Cornmun. 1983 700.l9 T. Chivers. M. N. Sudheendra Rao and J. F. Richardson J. Chem. Soc. Chem. Commun. 1983 702. 122 F. J. Berry C C N(5) Figure 4 The structure of (Ph2PN),N2S showing 50% probability ellipsoids and the atomic numbering scheme. For clarity only the a-carbon atoms of the phenyl rings are shown (Reproduced by permission from J. Chem. SOC. Chem. Commun. 1983 700) ring at 150-185 "C into the spirocyclic compound Ph,P4N,S was reported. The intermediate (Figure 5) contains a trans dimethylamino substituent on each of the two sulphur atoms. The endocyclic S-N bond lengths were found to be considerably shorter [1.590(5) A] than the exocyclic bond lengths of 1.703(3) 8 which is close to the value expected for a S'"-N single bond.The S-N bond lengths and pyramidal geometry at N(4) suggests that there is very little .rr-bonding between the exocyclic nitrogen atom and S(1). The compound (Ph2PN),(NSNMe,) is the first example of a ring system with more than eight atoms in the mixed phosphazene-thiazyl series (R,PN),(NSR') and as such suggests that this class of inorganic heterocycles is potentially extensive. The progress of the oxidation of the trisulphur trinitride anion by molecular oxygen in acetonitrile solution and the structures of the various ions that are formed has been studied" by I5Nn.m.r. Four major products were identified SON5-,S4N50- S3N30- and S3N302-and their relative yields were shown to be a function of the flow rate of oxygen. The S3N30-and S3N302-anions were found to possess six-membered S3N3rings with the exocyclic atoms bonded to sulphur.The significant variations in chemically equivalent bond lengths and angles which were observed in both rings were associated with the electronic structures of the ions. Several studies of metal complexes of sulphur-nitrogen compounds have appeared with an investigation*' of copper(11)-N,S2 complexes of bidentate N-substituted p-aminothiones illustrating the potential relevance of such studies to current interests in metal-containing molecules of biological significance. The bis(a p-unsaturated N-substituted P-aminothione)copper(rr) complex synthesized at low T. Chivers A. W. Cordes R. T. Oakley and W. T. Pennington Inorg. Chem. 1983 22 2429. '' P. Beardwood and J. F. Gibson J.Chem. SOC.,Chem. Commun. 1983 1099. 0,S Se Te 123 Figure 5 The structure of (Ph2PN),(NSNMe,) showing 50% probability ellipsoids and the atomic numbering scheme. For clarity only the a-carbon atoms of the phenyl rings are shown (Reproduced by permission from J. Chem. SOC.,Chem. Commun. 1983 702) temperature showed intense S -Cu charge transfer bands and gave e.s.r. spectra indicative of pseudo-tetrahedral CuN2S2 co-ordination similar to that found for the type 1 centres in blue copper proteins. In another study” of the metal complexes of sulphur-nitrogen chelating agents the chemistry of palladium(I1) complexes with some monoanionic tridentate ligands of the type SNN have been reported. A report has appeared23 of the preparation of the compounds [M(OS3N2),][AsF6]2 (M = Zn or Cd) in which the metal atoms are co-ordinated by six five-membered heterocyclic OS3N ligands.The structures of these compounds determined by X-ray analysis showed the metal to be bonded to each ligand via the exocyclic oxygen atom giving a slightly distorted octahedral environment. The S3N2 rings have an envelope conformation where the sulphur atom connected to the oxygen is out of the plane formed by the other four atoms. The AsF,- group which is slightly disordered in the cadmium compound is considerably disordered in the zinc analogue. It is also interesting to record a report24 of the essentially quantitative reaction between solutions of S,NAsF in liquid sulphur dioxide and elemental 22 R. Roy S. K. Mondal and K.Nag J. Chem. Soc. Dalton Trans. 1983 1935. 23 H. W. Roesky M. Thomas J. W. Bats and H. Fuess J. Chem. Soc. Dalton Trans. 1983 1891. 24 W. V. Brooks G. K. MacLean J. Passmore P. S. White and C. M. Wong J. Chem. SOC.,Dalton Trans. 1983 1961. 124 F. J. Berry chlorine or bromine to give (SX),NAsF (X = CI or Br). The resemblance of the vibrational spectrum of (SBr),N+ to that of (SC1)2Nt of known structure was supported by a normal co-ordinate analysis of (SX),N+ which also indicated some positive interaction between the halogen atoms in (SX),N+ and which was related to the cis-planar geometry of these cations. Attempts to prepare (SF),NAsF were unsuccessful although bis(difluorothio)nitronium hexafluoroarsenate(v) (SF,),NAsF, was synthesized from the reaction of S2NAsF6 with XeF in liquid SO,F,.The structure determined by X-ray diffraction showed evidence of interac- tions between discrete (SF,),N+ and AsF,- species .and the (SF2)2N+ chain was found to possess approximately C2 symmetry with essentially eclipsed fluorine- sulphur bonds when viewed along the sulphur-sulphur axis. It is also relevant in this section on compounds containing sulphur and nitrogen to note that studies” by X-ray photoelectron spectroscopy of the S-N bonding character of carbonyl- stabilized sulphilimines and their salts have suggested a strong interaction between S+ and N-through the u bond. Substantial interest has also been shown in compounds containing sulphur and other main-group elements. It is interesting to note the attention being given to sulphur-phosphorus compounds for example the one-dimensional compound PV2S,o which has been obtained26 by heating the elements in stoicheiometric propor- tions at 490 “C in evacuated tubes.The structure consists of [V,S,,] units forming chains which are linked two by two by [PS,] tetrahedra. In these units each vanadium is surrounded by eight sulphur atoms to give a distorted bicapped triangular prism which by sharing a rectangular face with another prism forms the [V,S,,] groups in which the intercation distance implies the presence of vanadium-vanadium bonds. Only weak S-S van der Waals bonds appear to exist between the infinite double chains the majority of the sulphur atoms were described as [S-S]- pairs and the rest as s’-anions.A different mode of examination was used in the investigation2’ of the molecular structures of gaseous bis(difluorophosphino) sulphide S(PF2)2 and bis( difluorophosphino) selenide Se( PF2), which were determined by electron diffraction. Both molecules were found to have average structures with CZvsymmetry and very large amplitude torsional vibrations. Gaseous difluoro(methy1thio) phos- phine PF,(SMe) was also examined. It is interesting to note the reported cleavage of P4S3 and P,Se cage molecules by transition-metal-ligand systems.** In these experiments the reactions of tetra-phosphorus trisulphide and tetraphosphorus triselenide with [RhCl(cod)l2 (cod = cyclo-octa-1,5-diene) in the presence of triphos [triphos = 1,1,1 -tris(diphenylphosphinomethyl)ethane] was found to give compounds formu- lated as [(triphOS)Rh(P,X,)].c6H6 (X = S or Se).The X-ray crystal structure of [{MeC(CH,PPh,),)-{ M(P3S3)}].C6H showed that the (triphos)Rh moiety had replaced a basal phosphorus in the cage molecule. 25 S. Tsuchiya and M. Sano J. Chem. SOC.,Chem. Commun. 1983 413. 26 R. Brec G. Ouvard M. Evain P. Grenouilleau and J. Rouxell J. Solid Srare Chem. 1983 47 174. D. E. J. Arnold G. Gundersen D. W. H. Rankin and H. E. Robertson J. Chem. SOC.,Dalton Trans. 27 1983 1989. 28 M. Di Vaira M. Peruzzini and P. Stoppioni J. Chern. SOC.,Chem. Comrnun. 1983 903. 0,S Se Te 125 It is also interesting to note the preparation? during a study of the preferred conformations in chalcogen-substituted ylides of triphenylC(phenylselen0)-(pheny1thio)methylenel phosphorane (C,H&P=C( SC6H5)Se(C6H5) which was shown to consist of unassociated units with a planar skeleton of phosphorus selenium and sulphur atoms around the ylidic carbon atom.The phenyl rings at the chalcogen atoms were located on opposite sites of the heavy atom plane with similar angles of inclination and the overall conformation considered in terms of the minimization of lone-pair repulsions. It is also interesting to record the reported3* reaction of sulphur with the diphosphine ArP=PAr [Ar = 2,4,6-B~'~(c,H,)] which led to the isolation and subsequent X-ray structure analysis of the diphosphene monosulphide ArP(S)=PAr. When treated with hexamethylphosphorus triamide the compound reverted to the starting diphosphine but thermal and photochemical -isomerization of the compound gave the thiadiphosphirane ArP-S- PAr.Several investigations of compounds containing sulphur and arsenic have been reported. The vibrational spectra3' of solid a-and P-As4S4 and the Raman spectra of molten As,S have suggested that As,S molecules of D, symmetry are retained in the molten state. The melt was also shown to undergo partial decomposition during prolonged laser irradiation. In another a polymeric bis(sulphiny1- nitri1o)sulphur complex of silver( I) [Ag4{ S(NSO),},][AsF6],.SO2 was isolated from the reaction of AgAsF with S(NS0)2 in liquid sulphur dioxide. The structural determination showed the presence of two crystallographically independent silver atoms.One lay on a three-fold axis and was octahedrally co-ordinated by the terminal oxygens of six S(NSO)2 ligands the other occupied a general position and was unsymmetrically co-ordinated by the nitrogen atoms of three S(NS0)2ligands. The ligands were found to bridge the silver atoms to form a polymeric cationic network containing holes in which the AsF,- anions and SO2 solvent molecules were accommodated without themselves acting as ligands. In a subsequent the reaction of trimeric thioformaldehyde with AgAsF in liquid sulphur dioxide was found to give the compound [Ag2((CH2S)3},][AsF6]2.S02. X-Ray crystallography showed that the silver atoms in the isolated L,AgLAgL2 (L = ligand) cations possessed irregular co-ordination geometry with one silver being co-ordinated by four sulphurs from three ligands and the other by five sulphurs from three ligands.By far the largest interest in sulphur-containing compounds has been directed towards those containing metallic elements. Although some of these have involved straightforward studies such as the preparation3 of single crystals of a number of anhydrous sulphites of strontium barium lead cadmium and manganese by gel crystallization methods and their examination by infrared Raman and thermoana- lytical techniques the most significant attention has been given to compounds with 29 H. Schmidbaur C. Zybill C. Kruger and H. J. Kraus Chem. Ber. 1983 116 1955. 30 M. Yoshifuju K. Shibayama N. Inamoto K. Hirotsu and T. Higuchi J.Chem. SOC.,Chem. Comrnun. 1983 862. 3' V. W. Bues M. Somer and W.Brockner Z. Anorg. Allg. Chem. 1983,499 7. 32 H. W. Roesky M. Thomas P. G. Jones W. Pinkert and G. M. Sheldrick J. Chem. SOC.,Dalton Trans. 1983 1211. 33 H. W. Roesky H. Hofmann P. G. Jones W. Pinkert and G. M. Sheldrick J. Chem. SOC.,Dalton Trans. 1983 1215. 34 V. H. D. Lutz W. Buchmeier W. Eckers and B. Engelen Z. Anorg. Allg. Chem. 1983 496 21. 126 F. J. Berry potential biological relevance. In this context the synthetic Fe,S cluster has received attention as a model compound for the active site of bacterial hydrogenase and one has reported on the catalytic properties of the phenyl-lithium-activated Fe4S4C1:-cluster for hydrogenation reactions. Aspects of the chemistry of ferredoxin (Fd) proteins containing cubane-type [4Fe-4S] redox sites in which the prevalent electron-transfer process is represented as Fd,,([4Fe-4S]2+) -t e-== Fdr,,([4Fe-4S]+) have also been subject to The corresponding isoelectronic couple of synthetic analogues of these sites is [Fe,S,(SR),]*-+ e-+ [Fe4S4(SR),l3- and the structural properties of the reduced clusters [Fe,S4(SR),l3- have been examined by a single crystal X-ray analysis of [(C2H5),N]J"e4S4(S-p-C6H4Br),].The Fe,S8 containing cluster (Figure 6) has a two-fold symmetry axis and exhibits a distortion from the idealized Zd symmetry of the [4Fe-4S]+ core which is different from that of (Et3MeN)3[Fe,S,(SPh)4] 2 Figure 6 The structure ofthe Fe,S8 portion 01[Fe4S,(S-p-C,H,Br),l3-as its Et,N' salt showing 50% probability ellipsoids selected interatomic distances and the atom-labelling scheme.Primed and unprimed atoms are related by the crystallographic twozfold symmetry axis (Reproduced by permission from Inorg. Chem. 1983 22 1550) 35 H. Inoue and M. Sata J. Chem. SOC.,Chern. Cornrnun. 1983 983. 36 D. W. Stephan G. C. Papaefthymiou R. R. Trankel. and R. H. Holm Inorg. Chem. 1983 22 1550 0,S Se Te 127 and ( Et4N)3[Fe4S4(SCH2Ph)4] which are the only other structurally defined reduced clusters. Current interest in synthetic analogues for the 4Fe-4S centres in non-haem-iron proteins is also reflected in a preliminary communication3' of the synthesis and structural characterization of bis(tetrapheny1phosphonium)-bis(ethy1dithiocarbamato) -bis(thiopheno1ata) -tetrakis(p3 -sulphido)tetraferrate (Ph4P)2[Fe4S4(SPh)2( Et2dtc)J in which a new cubane type cluster with mixed ter- minal ligands and two different modes of ligation on the Fe4S4 core has been identified.It is also interesting for chemical and biological reasons to note that the system MC12-Na,(S2-o-xyl)-Li2S in a 3 :3 1 ratio in ethanol (M = Fe") or acetonitrile-ethanol (M = Co") gives the trinuclear complexes [M3S(S2-o-xyl),12- (S2-0-xyl = o-xylene-a,a'-dithiolate) which may be isolated as Et4N+ salts.38 The complexes contain an apical p3-S atom bonded to three metal atoms arranged in a nearly equilateral triangular array. Each metal atom is co-ordinated to one terminal and one bridging sulphur atom of a dithiolate ligand giving distorted-tetrahedral M"S4 units in structures approaching overall C3 symmetry.The isotopically shifted 'H n.m.r. spectra of the complexes demonstrated the retention of the solid-state structure in acetonitrile solutions. The solution phase spectral and magnetic properties were indicative of MI'S chromophores similar to those present in the mononuclear tetrahedral complexes [M(S,-o- xyl),12-. These species and the recently reported [Fe,S(S,-o-~y1)-4,5-Me~)~]~-, provide the first examples of the occurrence of discrete pyramidal M3(p3-S)fragments in weak-field complexes with the two Fe" complexes and [Fe3(p2-S),( SR),I3-being the only structurally characterized trinuclear Fe-S-SR species of abiological origin. In other structural studies of compounds containing iron and sulphur a series of binuclear sulphur- and polysulphur-bridged organoiron complexes (p-S ) -[CpFe(C0),I2 x = 1-4 and Cp = have been prepared3' by substitution reactions and in investigations4' of iron(] I) complexes of N-substituted bidentate and tetradentate thiosalicyclideneimines several spin-paired Fe'" compounds con- taining SN,-bonded tridentate ligands have been identified.Attention has also been given to compounds containing sulphur iron and other transition metals of which molybdenum and tungsten appear to be popular. For example the synthesis of the (C6H5),P+ and (C2H,),N+ salts of the [(C~HI,S)~F~S~MS~]~-and [(S5)FeS2MS2I2- complex anions (M = Mo or W) have been examined4' and X-ray crystallography has shown the [(C6H5)4P]2[S5FeS2MS2] complexes to be isomorphous and isostructural with the structural properties of the [(C6H5)4P]2[(C6H5S)2Fes~Ms~] (M = Moor W) complexes being described in detail.The ,'Fe Mossbauer chemical isomer shifts were discussed in terms of extensive Fe -+ S2MS2 charge transfer and found to be slightly smaller for the WS2-complexes than for the corresponding MoS,~-complexes. The less pronounced electron 37 M. G. Kanatzidis M. Ryan D. Coucouvanis A. Simopoulis and A. Kostikas Inorg. Chem. 1983 22 179. 38 K. S. Hagen G. Christou and R. H. Holm Inorg. Chem. 1983 22 309. 39 M. A. El-Hinnawi A. A. Aruffo B. D. Santarsiero D. R. McAlister and V. Schomaker Inorg. Chem. 1983 22 1585. 40 P. J. Marini K.S. Murray and B. 0.West J. Chem. Soc. Dalton Trans. 1983 143. 4' D. Coucouvanis P. Stemple E. D. Simhon D. Swenson N. C. Baenziger M. Draganjac L. T. Chan A. Simopoulis. V. Papaefthymiou A. Kostikas and V. Petrouleas Inorg Chem.. 1983 22 293. 128 F. J. Berry delocalization in the WS2-species was also reflected in the electronic spectra and the electrochemical properties of the complexes. Another investigation4‘ of com- pounds containing sulphur iron and tungsten is worthy of note since although dinuclear complexes containing a bridging CS2 molecule are well known the preparation and structural determination of 1,1,2,2,3,3,3,3,3-n0nacarbonyl-1,2-bis(7)-cyclopentadienyl) -p3-[sulphido( thiocarbonyl) -C(Fe’)S( Fe2)S’( W3)] -di -irontung-sten shows the existence of a novel heteronuclear complex triply-bridged by carbon disulphide.There has also been much interest in compounds containing sulphur and molyb- denum without any other transition metals. For example the refined crystal structure43 of [bis@-methoxyphenyl)diazenido][ N,N’-dimethyl-N,N’- bis(mer- captoethyl)ethylenediamine]molybdenum(vr) a molybdenum (VI) compound with a tetradentate N2S2ligand was shown to possess a surprising non-equivalence of the molybdenum-amine bonds which was attributed to ‘inherent ligand strain’. In another the stereochemistry of R2PX2- ligands (X = S2 OS or 0,)in molybdenum-containing dimers and polymers were investigated. The stereo-chemistry about molybdenum(I1) was related to the bond angle about X such that the sulphur ligand was found to accommodate much smaller angles (typically 85-100°) than oxygen.It is also pertinent to record the reported45 preparation of the complex [MoCl,(thf),] (thf = tetrahydrofuran) in high yield by the reduction of [MoCl,(thf),] in tetrahydrofuran with tin and the reaction of the complex with [NH,][S,P(OMe),] in dry methanol to give [MO(S,P(OM~),}~] in which molybdenum adopts pseudo-octahedral co-ordination. It is interesting to note that a crystal structure determinati~n~~ of bis(tetrapheny1phosphonium)heptasulphide (Ph4P),S7 which was obtained by the reaction of MoS?-with an excess of the sodium salt of the diethyldithiocarbamate anions in acetonitrile solution showed the S:-anion to be a right-handed non- branched helix with very short terminal sulphur-sulphur bonds.The chemistry of thiometallates of molybdenum has been a subject of extensive investigation and reflects the key role of these complexes in biological processes including nitrogen fixation in addition to their unusual spectroscopic and structural properties. Although the structural chemistry of sulphide-bridged dinuclear com- plexes of molybdenum have received considerable attention in the past the properties of the analogous tungsten compounds have remained largely unexplored and it is therefore interesting to note the recent structural of the newly synthesized asymmetric dinuclear complex [SzW(p-S)2W(NNMe2)2(PPh3)]in which the central tungsten is trigonally pyramidally co-ordinated and the tungsten-tungsten separation is 3.024(1) A.The study also considered the diamagnetic symmetric dinuclear com- plex [{ W(SBU‘),(PM~,P~))~(~-S)~] which has a centre of symmetry that imposes planarity on the W,S2 system and in which the W-W distance of 2.736(2)8 may be interpreted in terms of a W=W bond. The tungsten atoms were shown to possess 42 L. Busetto M. Monari A. Palazzi V. Albano and F. Demartin J. Chem. SOC.,Dalton Trans. 1983 1849. 43 R. E. Marsh and A. Toy Inorg. Chem. 1983 22 1691. 44 J. H. Burk G. E. Whitwell J. T. Lemley and J. M. Burlitch Inorg. Chem. 1983 22 1306. 45 J. R. Dilworth and J. A. Zubieta J. Chem. Soc. Dalron Trans. 1983 397. 46 M. G. Kanatzidis N. C. Baenziger and D. Coucouvanis Inorg. Chern. 1983 22 290. 47 J. R. Dilworth R.L. Richards P. Dahlstrom J. Hutchinson S. Kumar and J. Zubieta J. Chem. SOC. Dalton Trans.. 1983 1489. 0,S Se Te 129 distorted trigonal bipyramidal geometry with the bridging sulphide and phosphorus species adopting apical sites. In another study48 which reflects the current interests in the tetrathiometallate anions of MeV' and Wv’ the ability of the reagents to co-ordinate to later transition metals which in the case of molybdenum has biological significance have been considered. In this investigation the utility of the copper thiomolybdates for the investigation of biological antagonism between copper and molybdenum which leads to copper deficiency in ruminant animals prompted the preparation spectroscopic and structural characterization of [(PhS)CuS2MoS2I2- and [(PhS)CuS,MoS2(SPh)l2- which are new additions to the family of discrete copper( I)-tetrathiomolybdate complexes.In investigation^^^ of new binary trinuclear Mo-S species M03S92-(and its tungsten analogue) has been prepared by heating (NH4)2MS4 (M = Mo or W) in N,N-dimethylformamide. The crystal structure of the (PPh4),Mo3S9 complex showed two external tetrahedral MoS units chelating a central square-pyramidal MoS unit. These Mo3Sg2-complexes were formulated as mixed-valence compounds and described in terms of a centred MoIV flanked by two MoV1 ions. In a study of cis-dinitrosylmetal complexes of Cr Mo and W with sulphur- containing chelating ligands,” octahedral complexes of the type cis-[M(chelate),(NO),] (M = Cr Mo or W) were prepared by the reactions of the solvent-stabilized dihalogenodinitrosylmetal fragments [MX,( (MX = CrCl, MoBr2 WBr,; solv = acetone or acetonitrile) with dithio chelating anions (chelate-= (CH,),AsS2- (CH3),PS,- (CH30),PS2- or (CH3),N-CS2-).Addi-tional chromium complexes using other chelating ligands were also reported. In another investigation” the preparation of several mono- and bis-thiolato mixed thiolato-monoalkylamido and thiolato-alkoxy complexes of nitrosyl[tris(3,5-dimethylpyrazolyl)borato] molybdenum were reported and the crystal and molecular structure of [MO{HB(~,~-M~,C,N~H)~)(NO)I(SC~H, ,)I described. A different type of interest is reflected in a study” of the electronic properties of the tetrathiotung- state(v1) ion [WS4J2-,as its [NH,]+ and [NBu,]’ salts by low temperature absorption and resonance Raman spectroscopy.Compounds containing sulphur and copper have also received noticeable attention as is exemplified in the first reports3 of a metal-promoted trimerization of carbon disulphide from the reaction of the complex [(PPh,),Cu(q2-BH,)] with CS2 to give the dinuclear copper(1) complex [(PPh3)2Cu(p-S2CSCH2SCS2)Cu(PPh3)2]. The X-ray crystal structure showed the two (PPh,),Cu fragments to be held together by a bridging S2CSCH2SCS22- ligand formed from a double head-to-tail condensation of three CS molecules. In another preliminary report54 the Cu-S-Cu angles in the cyclic molecule (p-SPh)3C~3(PPh3)4, which possesses a twist conformation and which is different from the planar (p-SPh)3Fe3 ring in [Fe3(SPh),C1,I3- were found to vary from 87 to 124” but to correlate with the inclination of the S-C bonds to 4n S.R. Acott C. D. Garner J. R. Nicholson and W. Clegg 1.Chem. SOC.,Dalton Trans. 1983 713. 49 W. H. Pin M. E. Leonowicz and El Stiefel Inorg. Chem. 1983 22 672. 50 M. Herberhold and L. Haumaier Chem. Ber. 1983 116 2896. ” J. A. McCleverty A. S. Drane N. A. Bailey and J. M. A. Smith 1.Chern. Soc. Dalton Trans. 1983 91. 52 R. J. H. Clark T. J. Dines and G. P. Proud J. Chem. Soc. Dalton Trans. 1483 2019. 53 C. Bianchini C. A. Ghilardi A. Meli S. Midollini and A. Orlandini J. Chem. SOC.,Chem. Cornrnun. 1983 545. 54 1. G. Dance L. J. Fitzpatrick and M. L. Scudder. I. Chem. Soc. Chem. Comrnun. 1983. 546. 130 F.J. Berry their Cu-S-Cu planes and to relate to the conformations of similar cycles in metallo-cysteine proteins. The attention currently being given to compounds of biological relevance is also reflected in as mentioned previously continued interest in the blue copper proteins and is further illustrated in studies” of the synthesis structures and electrochemistry of copper(I1) mercaptide complexes. In another study the (1,4,8,11-tetra-azacyclotetradecane)copper( I I) cation Cu(cyclam)” has been reported56 to react with pentafluorothiophenolate in alcohol solvents to give the complex formulated as Cu(cy~larn)(SC,F~)~. The six-co-ordinate complex was shown to be tetragonally elongated and to contain a square array of equatorial Cu-N bonds and weakly bonded axially disposed thiolate anions in which the Cu-S distances of 2.94 8 are comparable with the axial Cu-S bond in plastocyanin.The optical and e.s.r. spectra of the complex were associated with the effects of the axial thiolates on the electronic properties of the Cu” ion. Several studies of analogous copper and nickel compounds have also been reported. The synthesis of the novel mixed-donor nitrogen-sulphur macrocyclic ligand 1-thia-4,7-diazacyclononanehas been described5’ and its complexes with copper(rr) and nickel(I1) reported. The electronic spectra for the two complexes were discussed and the crystal structure of the nickel complex related to the possible origins of the high ligand-field strengths of the macrocycles. In another an improved method for preparing 1,4,7-trithiacycIononaneand the structures of its nickel(Ir) cobalt(r I) and copper(r1) complexes were described.The reactions of carbon disulphide with a number of nickel(o)-phosphine complexes has been reported59 to give two classes of Ni-CS2 co-ordination. Compounds containing sulphur and other first-row transition-metals illustrate other areas of current interest. For example bis(pentamethylcyc1open-tadienyl)vanadium(lI) has been shown6’ to bond to disulphur ligands to form [T~-(C~M~~)~V(~~-S~)~ which contains the persulphido ligand. In a study6‘ of thiocyanate-bridged transition-metal polymers the structural electronic and mag- netic properties of some mono (2,2’-bipyridyl) transition-metal thiocyanates prepared by thermolytic decomposition of the corresponding monomeric bis(bipyridy1) com- plexes have been reported.Results from X-ray diffraction near-infrared- visible- infrared- and e.s.r.-spectroscopy were consistent with a description of the complexes as polymeric zigzag chains with stepwise metal-thiocyanate bridging groups and six-co-ordinate metal centres (Figure 7). Sulphur-manganese compounds have also been examined in a study62 of the interaction of manganese(r1) with amino-acids and bidentate and tridentate ligands containing nitrogen oxygen and/or sulphur donor atoms. Other aspects of the solid-state chemistry of sulphur-containing compounds are illustrated by the reported63 phase diagrams of the quaternary systems MS-Cr2S3- In2S3 (M = Co Cd or Hg) and the investigations of these materials by high 55 0.P. Anderson C. M. Perkins and K. K. Brito Inorg. Chem. 1983 22 1267. 56 A. W. Addison and E. Sinn Inorg. Chem. 1983 22 1225. 57 S. M. Hart J. C. A. Boeyens J. P. Michael and R. D. Hancock J. Chern. SOC.,Dalton Trans. 1983 1601. 58 W. N. Setzer C. A. Ogle G. S. Wilson and R. S. Glass Inorg. Chem. 1983 22 266. 59 M. G. Mason P. N. Swepston and J. A. Ibers Inorg. Chem. 1983 22 41 I. 60 S. Gambarotta C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. SOC.,Chem. Commun. 1983 184. 6’ B. W. Dockum G. A. Eisman E. H. Witten and W. M. Reiff Inorg. Chem. 1983 22 150. 62 R. K. Boggess J. R. Absher S. Moreless L. T. Taylor and J. W. Hughes Inorg. Chem. 1983 22 1273. 63 H. D. Lutz W.W. Bertram B. Oft and H. Haeuseler. J. Solid State Chem. 1983. 46. 56. 0 S Se Te 13 1 cis-Thiocyanate -N cis-Thi 0cymate-S rlio CI Ic =2 2'-bipyridine r?I S 'C IN Ic I Figure 7 Proposed polymer structure for Mn(bpy)( NCS)* and Co(bpy)(NCS) (Reproduced by permission from Inorg. Chem. 1983 22 150) temperature X-ray diffraction X-ray powder diffraction d.t.a. t.g.a. and far-infrared spectroscopy. Complete series of mixed crystals were formed among the spinel-type compounds MCr2S4 MIn2S4(M =Cd or Hg) and In2S3. In the sections CoCr2S,- CoIn2S4 and CoCr,S4-In2S relatively large miscibility gaps were found to exist as a result of a change from normal to inverse spinel structure. The interchangeability of both systems was found to increase with increasing temperature and at tem- peratures exceeding 1000 "C complete series of solid solutions were formed which 132 E J.Berry could be quenched to ambient temperature. Superstructure ordering similar to that of ordered a-In$ was found in the indium-rich region of the MIn2S4-In2S3 solid solutions. It is also interesting to note the preparation and examination of the crystallographic and magnetic properties of members of the systems CoI-,Ru,S2 (0 < x < 1) and Fthl-,Ru,SZ (0.5 < x < 1). From a comparison with the system CO,-~R~,S~ it was proposed that the 4d electrons of Rh(4d’) are localized in the presence of Co(3d7) but delocalized in the presence of Ru(4d6). The magnetic susceptibility of the system Co -,Ru S2was found to be sensitive to the homogeneity of the products and indicative of the behaviour of Ru(4d6) as a diamagnetic ion.Informative SCF-Xa-SW calculations have been carried on the model compounds [M(X,)(PH,),]+ (M = Rh or Ir; X = S or Se) during an investigation of the electronic structure and bonding in complexes containing side-on bonded disulphur and diselenium. The calculations predicted an X-X bond order of about 1 and revealed that the M-X2 covalent interaction increases along the sequence RhSe2 < IrSez < RhS < IrS2. The side-on bonded S2 and Se groups were con- sidered as molecules with excited configuration and the M-S2 and M-Se bonds described in terms of in-plane 7~ overlap of an S2 or Se2 7~;forbital with a metal px + d, hybrid of predominantly px character and of a overlap of a metal 6 + pz hybrid with S2 or Se ‘rrll and pa orbitals.The interest in compounds containing sulphur and second- or third-row transition- metal elements has also been maintained. For example sulphur-containing dinuclear rhodium complexes such as [Rh2(p-SBu‘),(CO),{ P( OMe),},] have been reported66 to catalyse selectively the hydroformylation of hex-1-ene at low pressure and tem- perature. The synthesis of new rhenium nitrene complexes has been described6’ and the trans-Re(OC2H5)(p- NC6H4Me)(S2CNMe2) compound shown to contain six-co- ordinate rhenium in a distorted octahedral environment. In a study68 of di-and tri-thiocarbamate complexes of osmium a novel (selenodithiocarbamato) diosmium complex [OS~(CL-S~S~CNM~~)~(S,~NM~~),]PF~, was reported and the crystal struc- ture (see section on selenium) described.The complex [OS,(S~CNM~,)~]CI was also examined and shown to possess two isomeric structures which thermally interconvert in a manner similar to that identified in the ruthenium analogues. Complexes of the type Os[S2CNR2I3 were shown by ‘H n.m.r. to lack stereochemical rigidity. Interest in a variety of compounds containing sulphur and either platinum or palladium has also been evident and given the doubt concerning the struc- tural properties of some of these materials it is important to note the recent69 study of tetrasulphido[1,2-bis(diphenylphosphino)ethane]platinum(11). The [PtS4(Ph2PCH2CH2PPh2)] complex was found (Figure 8) to be approximately square planar and the tetrasulphido-ligand to behave as a dianionic chelating ligand with the resulting ptS4ring adopting approximately C2conformation.A molecular orbital 64 J. Foise K. Kim J. Covino K. Dwight A. Wold R. Chianelli and J. Passaretti Inorg. Chem. 1983 22 61. 65 A. P. Ginsberg J. H. Osborne and C. R. Sprinkle Inorg. Chem. 1983 22 254. 66 P. Kalck J. M. Frances P. M. Pfkter T. G. Southern and A. Thorez J. Chem. SOC.,Chem. Commun. 1983 510. 67 G. V. Goeden and B. L. Haymore Inorg. Chern 1983 22 157. 68 L. J. Mahen G. L. Miessler J. Berry M. Burow and L. H. Pignolet Inorg. Chem. 1983 22 405. 69 C. E. Briant M. J. Calhorda T. S. A. Hor,N. D. Howells and D. M. P. Mingos J. Chem. soc. Dalton Trans. 1983 1325.0,S Se Te 133 S(3) Figure 8 Molecular sfructure of [PtS,(dppe)] for clarity the hydrogen atoms on the phenyl rings have been omitted (Reproduced from J. Chem. SOC., Dalton Trans. 1983 1325) analysis of the bonding in this and related complexes was used to account for the observed alternation in S-S bond lengths within the PtS4 rings. In another study,” the dynamic ’ H n.m.r. spectra of several palladium(ii) complexes of cyclic sulphides in CHzC12 solution were measured at pressures up to 220MPa and the results considered in terms of the inversion process at sulphur and the achievement of ring planarity. The halogen oxidation reaction of tetrakis(dithioacetato)diplatinum(ii) has also been reported7’ and compounds of formula Pt2(MeCS2)4X2 (X = C1 Br or I) which have a formal oxidation state of +3 synthesized and characterized as diamagnetic compounds consisting of dimeric Pt2sSx2 units.Another product of formula R2(MeCS),I with formal oxidation state 2.5 was isolated from a reaction with a R:I ratio of 1 :0.5. X-Ray crystallography showed the structure to consist of linear chains of ...ptzSs...I...Pt2Ss...I... units stacking along the crystallographic b axis and to represent the first example of a linear-chain compound having dimeric [Pt2Ss] chromophores bridged through halides with a nearly symmetrical metal- halogen-metal bridge. The maximum powder electrical conductivity at 300 K of 7 X i2-I cm-’ showed an exponential temperature-dependence with a very low activation energy and was associated with a ‘hopping-type’ mechanism.Attention has been given7’ to the H20-S02-02 system because of its relevance to important processes such as sulphur dioxide-induced steel corrosion and the atmospheric oxidation of SO2to H2S04 which is a cause of environmental acidifica- tion. Given that the mechanism of the reactions especially the frequently rate 70 R. L. Batson-Cunningham H. W. Dodgen J. P. Hunt and D. M. Roundhill J. Chem. SOC. Dalron Trans. 1983 1473. ” C. Bellitto A. Flamini L. Gastaldi and L. Scaramuzza Inorg. Chem. 1983 22 444. 72 A. Stromberg 0.Gropen U. Wahlgren and 0.Lindquist Inorg Chem. 1983 22 1129. I34 F. J. Berry determining S'" +S"' oxidation step is poorly understood it is pertinent to record the series of a6 initio calculations on the sulphite ion SO:- and hydrogen sulphite ion HS03-or SO,OH- which were considered in terms of the polarization of the S'" electron pair.Another ab initio study was performed73 on the S02-HF complex and the most stable geometry found to be when the HF moiety was near to the S-0 bond separation of 1.8 A. Tetrathiafulvalene (TTF) and its derivatives have been of recent interest since it was found that with suitable acceptors they could form charge-transfer salts which behave as organic metals with high conductivity. A report74 of the preparation of tetraformyltetrathiafulvalene(TFTTF) with the potential to yield polyfunctionalized TTF from which a tetravinyl derivative could be readily obtained and which was shown by complexation with tetracyanoquinodimethane to be a good .rr-donor is therefore of considerable significance.The current interest in organic metals is also illustrated by the report75 of a new series of radical-cation salts based on an alkylated tetrathiafulvalene which were prepared by electro-oxidation of 2-(4,5-dimethyl- 1,3-dithiol-2-ylidene)-5,6-dihydro-4H-cyclopenta- 1,3-dithiole and which exhibited very promising electrical conductivity. In another the exposure of highly purified samples of the new polymers poly(2,5-thienylene sulphide) PTS and poly(2,5- thienylene selenide) PTSe to arsenic pentafluoride was found to give conducting complexes of which that derived from PtSe was superior. The results contrast with the behaviour of the poorly conducting poly(p-phenylene selenide) and conducting poly@-phenylene sulphide) complexes of AsF,.It is interesting to record the preparation" of tetrakis(trifluoromethylthiazyl) (CF,SN), which is stable at -30°C for a few days and which oligomerizes on standing for seven days at 20 "C to form a solid which melts above 180"C.It is also interesting to note that both Me,SiNSO and Me3SiN=S=NSiMe3 with tin tetrachloride to give the 1 :1 adduct Me3SiN=S=NSiMe3. SnCI in which the sulphur di-imide functions as a bidentate ligand. 4 Selenium Several important studies of selenium-containing compounds have been covered in the section dealing with s~lph~r'~~~~-~'~~~~~~~~~ and a few others warrant further comment here. For example it is pertinent to record that the Raman spectra recorded3' from As,Se were interpreted in terms of a cradle-type molecule possessing DZd symmetry and that the mechanism of selenium incor-poration in the (se1enodithiocarbamato)diosmium complex,68 [Os2(p-SeS2CNMe2)2(S,CNMe2)3]PF,,in which the selenium atoms occupy the bridging positions (Figure 9) was considered in terms of the initial bonding and activation of Se by osmium.Investigations of the solid-state chemistry of selenium-containing compounds have frequently stemmed from the technological interest in such compounds. For ?3 M. V. Friedlander J. M. Howell and A.-M. Sapse Inorg. Chem. 1983 22 100. 74 A. Gorgues P. Batail and A. Le Coq J. Chem. SOC.,Chem. Commun. 1983 405. 75 J. M. Fabre L. Giral E. Dupart C. Coulon and P.Delhaes J. Chem. SOC.,Chem. Commun. 1983,426. 76 K.-Y. Jen N. Benfaremo M. P. Cava W.-S. Huang and A. G. MacDiarmid J. Chem. SOC.,Chem. Commun. 1983 633. I7 D. Bielefeldt and A. Haas Chern. Ber. 1983 116 1257. 78 H. W. Roesky H. G. Schmidt M. Noltemeyer and G. M. Seldrick C'hem. Ber. 1983 116 1411. 0,S Se Te 135 Figure 9 Structure of the [OS,(S~S,CNM~,),(S,CNM~~)~]+ cation. The thermal ellipsoids are drawn with 30% probability boundaries (Reproduced by permission from Inorg. Chem. 1983 22 405) example recent years have seen the development of films of various metal chal- cogenides with semiconducting properties for application in various fields of tech- nology. It is interesting therefore to note the report79 of a solution growth technique for the deposition of thin films of degenerate and p-type semiconducting copper(r1) selenide.It is also relevant to record the preparation" of the compounds Nb2Se2Br, Nb2Te,Br, and Nb,Te21 from the elements in sealed quartz ampoules at 1073 K. The crystalline solids exhibiting metallic lustre and insensitive towards moisture and oxygen were shown by d.t.a. to undergo several reversible thermal transitions with temperature. The structures were found to consist of one-dimensional infinite chains of halogen-bridged Nb,(Y,)X (Y = Se or Te; X = Br or I) units containing side-on bonded Nb and Y dumbells forming quasi-tetrahedral Nb2Y2clusters. The structural and magnetic properties were consistent with the expected presence in these compounds of Nb4+ and Y-.X-Ray powder diffraction analysis at 300 K of CuGaSe and CuGaTe under high pressure showed8' a volume-induced transition '' A. Mondal and P. Pramanik J. Solid State Chem. 1983 47 81. H. F. Franzen W. Houle and H. G. V. Schnering 2. Anorg. Allg. Chem. 1983 497 13. '' V. A. Kraft G. Kuhn and W. Moiler Z. Anorg. AIIg. Chem.. 1983 504. 155. 136 F. J. Berry from the chalcopyrite-type to the NaCl structure for CuGaSe at 12.5 GPa and for CuGaTe at 8GPa. The new compound SrGa2Se has also been preparedg2 and shown to be a novel variant of the T1Se-structure-type. Some selenogermanates(1v) have been synthesizeds3 from aqueous solutions by reactions of alkali selenides with germanium diselenide and the compound Na,Ge,Se,. 16H20 obtained from syn- theses involving 1 :1 reactant ratios.The structure was shown to consist of isolated Ge2Sez- anions containing edge-sharing tetrahedra which are hydrogen bonded through Se. .-H-0 bridges to the hydrated octahedral [Na(H20)6]+ ions. The adamantane-like Ge,Se ,$-species was formed from similar reactions involving I :2 molar ratios of alkali selenide to GeSe,. In a studys4 of channel structures based on octahedral frameworks the crystal structures of TITi,Seg T1V5Se, and TICr,Seg were described and discussed in terms of their relationships with the TlV& and TlCr3S hollandite and psilomelane structures. It is pertinent to record the preparationg5 of [se,I'],,,,[AsF,-] which was shown by single crystal X-ray diffraction to consist of ASF6- species and polymeric strands of [Se,I'],,.The cation (Figure 10) was found to contain hexaselenium rings of chair conformation similar to that of cyclohexaselenium which were joined to two 0 Figure 10 View of the polymeric [Se,I'], cations (AsF,-omitted) showing the close contacts between chains (Reproduced by permission from J. Chem. Soc. Chem. Commun.,1983 526) 82 V. W. Klee and H. Schafer Z. Anorg. Allg. Chem. 1983 499 145. 83 V. B. Krebs and H. Muller Z. Anorg. Allg. Chem. 1983 496 47. 84 K. Klepp and H. Boller 1.Solid Stare Cbem. 1983 48 388. 85 W. A. Shantha Nandana J. Passmore. and P. S. White J. Chem. Sor. Cbem. Commun. 1983 526. 0,S Se Te 137 neighbouring hexaselenium rings by two weak [2.736(3) A] exocyclic 1,4 axial selenium-iodine bonds.The [Se,I+] cation is important because it is the first example of a derivative of a selenium ring and even more interestingly is a derivative of the recently discovered Se rather than the well known Se ring. The polymeric nature of the cation contrasts with the S71+species and may imply that selenium oxides such as Se,O and Se80 if they can be prepared may also have polymeric structures. Several trifluoro- and tribromo-selenate(1v) compounds of the type MSeOF and MSeOBr3 (M = K Cs or Me,N) have been examineds6 by infrared and Raman spectroscopy. The results were consistent with trigonal bipyramidal structures as predicted by VSEPR in which the oxygen atom and lone pair adopt equatorial positions. Anion polymerization via oxygen or halogen bridging which was very weak for MSeOF (M = K or Cs) became significant for KSeOCI and Me4NSeOBr3.Compounds with larger cations were found to contain isolated SeOX,- anions. The structures7 of the para-elastic phase of RbHSe04 which was determined at 387 K by neutron diffraction is interesting since it consists of chains of hydrogen bonded SeO groups extending along the crystallographic b axis. Two different types of hydrogen bond were characterized with the hydrogen in the shorter bond being disordered and consistent with the participation of hydrogen ordering in the phase transition to the ferroelectric phase. The interest in selenium complexes as organic metals has been mentioned earlier,76 and given that the novel two-dimensional metallic structure and superconductivity in charge-transfer salts of bis(ethy1enedithio)tetrathiafulvalene (BEDT-TTF) has been a significant development in organic metals research it is important to note the first reported, synthesis of the selenium analogue of BEDT-TTF bis(ethy- lenedise1eno)tetraselenofulvalene (BEDSe-TSeF) its characterization and the pre- paration of several charge-transfer salts of this new .rr-donor.The synthesis of dibenzotetraselenofulvalene (DBTSF) has also been reported89790 and the molecular structure (Figure 11) showns9 to be very similar to that of its sulphur-containing homologue (DBTTF) but with a larger molecular size resulting from the generally longer Se-C bonds. The DBTSF donor is also more chair shaped than DBTT’F and the intermolecular stacking is less dominant than the Se...Se intermolecular contacts which are close to the van der Waals separation.In this sense the structural motif of DBTSF is more reminiscent of the closely related tetramethyltetraselenaful-valene TMTSF. The preparation and characterization of several charge-transfer salts of DBTSF (ranging from insulators to metals) has also been rep~rted.~~’~~ In a study” of new tris( N,N-dialkyldiselenocarbamato)iron( ~v) tetrafluoroborate complexes four compounds of composition [Fe’V(Se2CNR2)3]+ where R = C2H5 or CH2C6Hs R2N = piperidino or morpholino were prepared as BF4- salts and examined by variable-temperature magnetochemistry Mossbauer- e.s.r.- and X-ray nh J. Milne and P. Lahaie Inorg. Chem. 1983 22 2425.87 J. Brach D. J. Jones and J. Roziere J. Solid State Chem. 1983 48 401. 88 V. Y. Lee E. M. Engler R. R. Schumaker and S. S. P. Parkin J. Chem. SOC.,Chem. Commun. 1983,235. 89 K. Lerstrup M. Lee F. M. Wiygul T. J. Kistenmacher and D. 0.Cowan J. Chem. SOC.,Chem. Commun. 1983 294. 90 I. Johannsen K. Bechgaard K. Mortensen and C. Jacobsen J. Chem. SOC.,Chem. Commun. 1983,295. P. Deplano E. F. Trogu F. Bigoli E. Leporati M. A. Pellinghelli D. L. Perry R. J. Saxton and L. J. Wilson J. Chem. Soc.. Dalton Trans.. 1983 25. 138 F. J. Berry Figure 11 The (010) projection of the crystal structure of DBTSF. The molecule labelled A is centred at (0 0 0) while molecule B is centred at d 0,i). Selenium atoms are shaded and closest Se.-.Se contacts (A) are indicated (Reproduced by permission from J.Chem. SOC. Chem. Commun. 1983 294) photoelectron-spectroscopies. The molecular structure of [Fe{ Se,CN(CH2C6HS)2}3- BF,] was determined by X-ray crystallography and shown (Figure 12) to possess D3 macrosymmetry with the FeSe core having six selenium donor atoms at the apexes of a co-ordination polyhedron which is intermediate between the idealized trigonal prismatic and trigonal antiprismatic geometries. The study showed the tris-diselenocarbamate complexes to be low-spin iron( IV) species with Fe'"Se cores and similar to their tris-dithiocarbamate counterparts. In other investigations of selenium-containing compounds the crystal structure"' of {[(C6HS)~P]2CSe)~+Fe20Cl~-.4cH2C12 has been shown to possess a linear Fe-0-Fe axis and selenium-selenium bond whilst the complex [Ir(Se,)-(Me2PCH2CH2PMe2)2]CI has been found93 to contain a five-membered IrSe ring.The structure determination of [Ba-2.2.2-Crypt]Se4.en has shown9 the hitherto unknown Se;- anions to be significant structural units. The new compound (mor- pholinecarbodiselenoato)selenium(II) iodide [OC,H,NCSe3]I has been reported95 and described in terms of polymeric - - -1. .Sea. -1- -.Sea -1. -chains running along the c-axis and held together by van der Waals contacts. Finally it is relevant to note 92 H. Schmidbaur C. E. Zybill and D. Neugebauer Angew. Chern. Int. Ed. Engl. 1983 22 156. 93 A. P. Ginsberg J. H. Osborne and C. R. Sprinkle Inorg. Chern. 1983 22 1781. 94 V.T. Konig B. Eisenmann and H. Schafer Z. Anorg. Allg. Chem. 1983 498 99. 95 F. Bigoli E. Leporati M. A. Pellinghelli G. Crisponi P. Deplano and E. F. Trogu 1. Chern. Soc. Dalton Tranc. 1983 1763. 0,S Se Te 139 C(25) Figure 12 Perspective view of the cation in [Fe{Se2CN(CH2C,H,),},IBF looking down the three-fold axis (Reproduced by permission from J. Chem. SOC. Dalton Trans. 1983 25) that elemental selenium has been found96 to be sparingly soluble in solutions of selenium dioxide in concentrated hydrochloric acid and the yellow solutions have been shown by gravimetric analysis and spectrophotometric studies to contain Se2C12 as the principal species in equilibrium with SeOCl,. 5 Tellurium Studies of some solid tellurium-containing compounds have been cited in the previous section^.^^^^^^' More specific interest in such materials is illustrated in the Vh M.Mahadevan and J. Milne Innrg. Chern.. 1983. 22. 1648. 140 F. J. Berry investigationY7 of the copper-tellurium system by d.t.a. d.s.c. and X-ray diffraction which enabled the construction of a phase diagram from which the phases described as Cu2_.,Te Cu3- rTe2 and CuTe have been defined. Several superstructures were observed in the homogeneity ranges of the non-stoicheiometric phases. Another binary compound of interest is Re,Te, which has been reported9' to crystallize in a new structure type having space group Pbca. This new [M,X,,] cluster compound formulated as {[Re,Te,]Te,} was shown to contain octahedral [Re,] clusters and the tellurium atoms were found to be amenable to replacement by selenium.Mixed oxides containing tellurium have also been subjected to examination. Compounds from the tellurium-molybdenum-oxygen and tellurium-vanadium- oxygen systems have been investigated" by e.s.r. and 12'Te Mossbauer spectroscopy. The data were interpreted in terms of the cationic oxidation states and their environ- ments and associated with the catalytic properties of these materials for the selective oxidation and ammoxidation of hydrocarbons. The reduction of Te2V209 by hydro-gen at temperatures between 300 and 450 "Chas been studied'" by X-ray diffraction e.s.r.- and infrared-spectroscopy and the process envisaged as being initiated by the formation of oxygen vacancies which give several types of transient V02+species.Further slow reduction up to ca. 350°C was found to give rise to the formation of TeVO,., and minor amounts of P-TeVO and at higher temperatures the binary oxides were shown to undergo rapid decomposition to V203. The magnetic interac- tion between the paramagnetic V4' ions in the products were related to the structural properties of the reduced oxides. The preparation of Pu,02Te has been reported"' and found to be isostructural with the corresponding rare-earth oxide tellurides which crystallize in the tetragonal La202Te-type system. Magnetic susceptibility data recorded between 4 and 298 K together with resistivity measurements showed Pu202Te to be an antiferrornagnet below 56 K and a semiconductor with an intrinsic energy gap of 0.65 eV.A new method for the synthesis of hypofluorites using fluorine fluorosulphate as the fluorinating agent has been applied'" to the synthesis in high yields of the new hypofluorite TeFSOF. This compound and related species were characterized by infrared Raman I9F n.m.r. and mass spectrometry. The preparation of new tellurium-nitrogen compounds containing the 5N-TeF group have been repor- tedlo3 and the material CI,Se=NTeF has been shown to be a rare example of a compound containing a discrete selenium-nitrogen double bond. The OTeF com- pounds of P As and Sb such as POF,-OTeF, P(OTeF,), O=P(OTeF,), As(OTeF,), and Sb(OTeF,) have also been describedIo4 and compgred with similar and characterized compounds. 97 R.Blachnik M. Lasocka and U. Walbrecht J. Solid Stare Chem. 1983 48 431. 98 F. Klaiber W. Petter and F. Hulliger J. Solid State Chem. 1983 46 122. 99 F. J. Berry and M. E. Brett Inorg. Chim. Acra 1983 68 25. I00 F. Cariati L. Esre G. Micera and J. C. J. Bart Z. Anorg. Allg. Chem. 1983,496 159. 101 J. M. Costantini D. Damien C. H. de Novion A. Blaise A. Cousson H. Abazli and M. Pages J. Solid State Chem. 1983 41 219. lo* C. J. Schack W. W. Wilson and K. 0.Christe Inorg. Chem. 1983 22 18. I03 M. Hartl P. Huppmann D. Lentz and K. Seppelt Inorg. Chem. 1983 22 2183. I04 D. Lentz and K. Seppelt 2. Anorg. Allg. Chem. 1983 502 83. 0,S Se Te 141 Investigations of telluronium salts formed from the reaction of NaTeR (R = p-EtOC6H or Ph) with organic dihalides (CH2),,X2 (n = 1,2,3 or 4) have shown'05 that when n = 1 (X = Br or I) the products may be formulated as charge-transfer complexes of stoicheiometry (RTe),CH2.CH2X2 whereas when n = 2 the elimina- tion of ditelluride gives rise to the formation of an alkene.The study demonstrated the NaTeR compound to be an effective dehalogenating agent for uic-dihalides. The '"Te Mossbauer parameters for (p-EtOC,H,Te),CH2.CH2Br were interpreted in terms of the removal of Sp-electron density from the spare-pair orbital uia the charge-transfer interaction. A kinetic and mechanistic study of the reaction between bis-p-ethoxyphenyl ditelluride and molecular iodine in solution has also been reported."' An investigationlo' of the crystal and molecular structure of [NBuil- [PhTeCl,I] has shown the arytellurium mixed halide anion PhTeC1,I- to be a square-based pyramid with a lone pair in the sixth position of an octahedron.The structure of the novel p,-Te[Mn(CO),( q2-C5H5)] complex has been foundlo8 to contain an almost planar p,-TeMn skeleton in which the central tellurium atom can be considered to function as a six-electron donor. It is also interesting to note the report'O' of the synthesis reactivity and n.m.r. spectra of (C5H,)RhFe,Te2(CO) (x = 6 or 7). Ius K. G. Karnika de Silva Z. Monsef-Mirzai and W. R. McWhinnie J. Chem. SOC.,Dalton Trans. 1983 2143. I06 R. T. Mahdi and J. D. Miller J. Chem. SOC.,Dalton Trans. 1983 1071. ID7 N. W. Alcock and W. D. Harrison J. Chern. SOC.,Dalton Trans.1983 2015. I08 M. Herberhold D. Reiner and D. Neugebauer Angew. Chem. Ini. Ed. Engl. 1983 22 59. I09 D. A. Lesch and T. B. Rauchfuss Inorg. Chern. 1983 22 1854.

ISSN:0260-1818    

DOI:10.1039/IC9838000117

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

7 F CI,Br I At and Noble Gases By J. M. WINFIELD Department of Chemistry University of Glasgow Glasgow GI2 8QQ 1 Introduction Surface enhanced Raman scattering (SERS) from electrogenerated chlorine on a Pt electrode has been interpreted in terms of the formation of both linear (1) and bridged (2) or (3) adsorbed Clz species.'" Adsorbed I2 and I,-species have been detected on Pt and Pd metals by a similar technique.lb C1 I C1 I C1 IPt Pt \Pt The weak bond in F2 has a profound influence on its chemistry and has usually been accounted for by postulating high lone-pair-lone-pair repulsion in the molecule. Core and valence ionization potentials of this and related molecules have been used to evaluate the ionization potentials that atomic orbitals in molecules would have if they were non-bonding.Comparison between these and experimentally derived T and T* ionization potentials provides strong evidence for lone-pair repulsion in F2 and possibly also in ClF. Such repulsion is absent in C12 Br I, IC1 and IBr.' 2 Interhalogens and Related Ions Reactions which occur between I2 and good Lewis bases (B) have been widely studied one reason being that they often result in equilibria involving the ions B21+ and I,-. These and other aspects of I' co-ordination chemistry have been re~iewed;~" they feature also in a review of the electrochemistry of iodine.3b The electrochemistry of 1-/13- and I-/Iz redox processes is complicated by adsorption (cj rej 16) and universally accepted explanations of observed electrochemical phenomena are still not available.Formation of B2X+ (X = C1 or Br) cations in solution has been postulated although these halogens have been less well studied than has 12. However the Raman spectra of CI and Br solutions in N,N-disubstituted amide solvents ' (a) B. H. Loo,J. fhys. Chem. 1983 87 3003; (b)Solid State Commun. 1982 43 349. W. L. Jolly and C. J. Eyermann,'Inorg. Chem. 1983 22 1566. (a) Yu. N. Kukushkin and V. N. Demidov Koord. Khim. 1983,9 1299; (b) Ya. A. Yaraliev Russ. Chem. Rev. (Engl. Trans[.) 1982 51. 566. 143 144 J. M. Winjield indicate that X3- and so presumably solvated X+ are present,4a and bis(quinu- clidine) brcmine(1) has been isolated as its BF,- salt (4).4h Its X-ray crystal structure shows that the N-Br-N moiety is linear.I2 is oxidized by MoF in MeCN to give the I(NCMe),+ cation which is isolated as the MoF,- salt. A linear N-I-N skeleton is suggested from its vibrational spe~trum.~ Most of the reports on astatine in this period focus on its similarity to iodine. Formation constants of AtX2- (X = Br I CN or SCN) have been determined in acidic aqueous solution by electromigration methods.6a At1,- is stable to pH 12 whereas AtX2- (X = C1 Br or SCN) under these conditions are reduced to At-. Cationic complexes of At' with thiourea or its substituted derivatives have been identified in aqueous solution,6h and (H,O)Atf is believed to be the active species in astatobenzene formation from C6H6 and At in aqueous acid.6" An electron diffraction study of BrF vapour indicates that it has the expected T-shaped structure like ClF3,7U and the structures of halogen fluorides and oxo-fluorides have been reviewed.7h Complex formation is a characteristic of BrF, and several of its adducts with the fluorides of RlV,Sn'" IrV and Au"' have been studied in the solid state by I9F n.m.r.spectroscopy. Ionic structures are postulated in each case.8 The ability of BrF2' CIF2+ or BrF,+ to fluorinate aromatic fluorine compounds has been demonstrated. For example perfluorocyclohexa- 1,4-diene is formed from C6F6 and BrF,SbF,. The cations are more reactive in this respect than the parent halogen fluorides.' Other salts containing triatomic halogen cations which have been fully characterized this year include [IBr2][Sb2F ,I prepared from IBr and SbF in SO2 and [IBro.75CII.25][SbC16] in which the cation is disordered and which is prepared from IBr SbCI, and C12 in the same solvent.Their X-ray crystal structures indicate that both cations are bent bond angles at I are 100.0" and 97.7"respectively the cation-anion arrangement being such that I"' has a trapezoidal four-co-ordina- tion involving two cis-bridges (I-.Y-Z) to the anions (5). The I2'I Mossbauer spectra of these compounds are dominated by the primary bonds to I"' which are largely of p character." (a) M. De Meyer J. M. Levert and A. Vanclef Bull. SOC. Chim. Belg. 1983 92 347; (b) L. K. Blair K. D. Parris P. S. Hii and C. P. Brock J. Am. Chem. Soc.. 1983 105 3649. ' G. M. Anderson 1. F. Fraser and J.M. Winfieid J. Fluorine C'hem. 1983 23 403. '(a)R. Dreyer I. Dreyer F. Rosch and G.-J. Beyer Radiochem. Radioanal. Lett. 1982 54 165; R. Dreyer I. Dreyer M. Heiffer and F. Rosch ibid. 1983,554 207; (b)R. Dreyer I. Dreyer F. Rosch and S. Fischer Z. Chem. 1983 23 346; (c) L. Vasaros Yu.V. Norseyev D. D. Nhan and V. A. Khalkin Radiochem. Radioanal. Lett. 1982 54 239. ' (a)A. A. Ishchenko I. N. Myakshin G. V. Romanov V. P. Spiridonov and V. F. Sukhoverkhov Dokl. Akad. Nauk SSSR 1982 267 1143; (b) Yu. A. Buslaev V. F. Sukhoverkhov and N. M. Klimenko Koord. Khim. 1983 9 101 I. V. N. Mit'kin Y. I. Mironov S. V. Zemskov B. D. Zil'berman and S. P. Gabuda Koord. Khim. 1983 9 20. V. V. Bardin G. G. Furin and G. G. Yakobson J. Fluorine Chem. 1983 23 67. T. Birchall and R.D.Myers Inorg. Chem. 1983 22 1751 J. Chem. Soc. Dalton Trans. 1983 885. F Cl Br I At and Noble Gases /--. X y Z (5) CI3+ and Br3+ are among the products observed in the low temperature (12 K) Raman spectra of N02,HX (X = C1 or Br) mixtures which have been equilibrated at room temperature for 1h. Formation of C1,+ is suggested to occur via the reactions C12 +C1N02 and C12 +ClN03." The I:+ cation has been fully characterized in two salts red 14(ASF6)2 and black 14(Sb3F1,)(SbF,). Both are prepared by oxidation of I2 with the appropriate pentafluoride in SO2.The cation is rectangular (Figure 1) and can be described as two I,+ cations held together by two relatively weak bonds." A similar conclusion was reached from a Mossbauer study reported last year.F Figure 1 One ofthe cations from I,(SbF,)(Sb3F,,). The bond lengths (A) and angles (") are listed in orderfor the cation in I,(AsF,) and the two carions in I,(SbF,)(Sb3F,,) (Reproduced from J. Chem. SOC.,Chem. Commun. 1983 8) Considerable progress has been made in the preparation and characterization of ClF6+ salts. The AsF6-salt is prepared by oxidizing CIF with KrFAsF,,l3" and the BF4- salt by low-temperature metathesis in anhydrous HF from CIF6AsF6.'3h The compounds' spectra are in accord with the presence of octahedral cations. ClF,+ can be compared with NF,+ as both cations are co-ordinatively saturated. A report describing the preparation of (C1F6)(CUF4) has been shown to be incorrect. In reality the compound isolated was [CU(H,0),][SiF6].'4 " L.-H.Chen. E. M. Nour and J. Laane J. Raman Specfrosc. 1983 14 232. R. J. Gillespie R. Kapoor R. Faggiani C. J. L. Lock M. Murchie and J. Passmore J. Chem. SOC. Chern. Commun. 1983 8. l3 (a) K. 0.Christe W. W. Wilson and E. C. Curtis Znorg. Chem. 1983 22 3056; (b)K. 0.Christe and W. W. Wilson ibid. p. 1950. l4 H. G. Von Schnering and Dong Vu Angew. Chern.. Int. Ed. EngL 1983 22 408. 146 J. M.Winjield Phenyliodine(II1) carboxylates are widely used reagents in organic chemistry and this interest has been extended to perfluoro-analogues. The crystal structure of C6F51[OC(0)C6F,] shows the presence of distorted T-shaped molecules which have weak intermolecular contact^.'^ The reactions of aryliodine(Ir1) or aryliodine(v) fluorides with PhSO,N(SiMe3) lead to the phenylsulphonylimino-derivatives Ar1=NSO2Ph and ArI( =NS02Ph)2.'6 Several chelated hydroxycarboxylic acid derivatives of IF5 for example IF,[OC(O)CH,O] have been identified in solution by 19F n.m.r.spectroscopy. Axial-equatorial chelation around the square pyramidal I" centre is the preferred co-ordination mode." 3 Noble Gas Compounds Cr(CO),Xe has been identified by i.r. spectroscopy as a relatively long-lived ti = ca. 2s at 175 K species following U.V. photolysis of Cr(CO) in liquid Xe.18 This element is also useful as a cryogenic solvent for uranium halides. The u.v.-visible spectrum of UC1 has been obtained in liquid Xe ca. 163 K,I9' and i.r. spectra assigned to UF,-,Cl mixtures have been observed under similar condition^.'^' The v3 vibra-tional band of UF obtained from a frozen solution in Xe consists of a single sharp feature,'" and there is no evidence for multiple trapping-site effects characteristi- cally observed in deposition matrix spectra.The conversion CH3S- into CH2FS- in methionine and methionylglycine deriva- tives is readily achieved using XeF in MeCN at or below room temperature,200 and a high yield synthesis of 2-['8F]fluoro-2-deoxy-~-glucose using Xe * 'FF and BF3,0Et2 as catalyst has been reported by two groups.20b This "F-labelled compound is a potential brain scanning agent in positron emission transaxial tomography (See also Section 5). The oxidative fluorinating abilities of Xe fluorides and KrF have been exploited in syntheses of tetravalent lanthanides LnF (Ln = Ce Pr or Tb) and Cs3LnF7 (Ln = Ce Pr Nd Tb Dy or Tm).The thermally unstable PrF is accessible only using KrF2.21 Physico-chemical studies involving Xe fluorides continue to be reported. The fusion and boiling points of XeF are 409 f5 K and ca. 61 1 K respectively the enthalpy of fusion being 14.04 f2.09 kJ mol-I. Disproportionation of XeF to XeF + Xe is observed above 623K.22a The activation energy for the reaction of Xe with O,SbF to give FXeSb,F, and O2 has been determined as 71.1 f 8.4kJmol-'.22b X-Ray P.E. spectra of core levels of KrF and Xe fluorides have been obtained,23 including satellite spectra assigned with the aid of Xa calculations H. J. Frohn J. Helber and A. Richter Chem.-Ztg. 1983 107 169. l6 I.I. Maletina A. A. Mironova V. V. Orda and L. M. Yagupolskii "wiis 1983 456. l7 Y. V. Kokunov S. A. Sharkov and Yu. A. Buslaev Koord. Khim. 1983 9 912. '* M. B. Simpson M. Poliakoff J. J. Turner W. B. Maier 11 and J. G. McLaughlin J. Chern. SOC. Chem. Commun. 1983 1355. 19 (a)W. B. Maier 11 R. F. Holland and W. H. Beattie Spectrosc. Lett. 1983 16 233; (b)W. €3. Maier 11 W. H. Beattie and R. F. Holland J. Chem. SOC.,Chem. Commun. 1983 598; (c)R. F. Holland and W. B. Maier 11 Spectrosc. Lett. 1983 16 409. 2o (a)A. F. Janzen P. M. C. Wang and A. E. Lemire J. Fluorine Chem. 1983 22 557; (b)S. Sood G. Firnau and E. S. Garnett Int. J. Appl. Radial. Isot. 1983 34 743; C.-Y. Shiue K.-C. To and A. P. Wolf J. Labelled Comp. Radiopharm. 1983 20 157. *' V. I.Spitzin L. I. Martynenko and Ju. M. Kiselew 2. Anorg. Allg. Chem. 1982 495 39. 22 (a)Yu. M. Kiselev and S. A. Goryachenkov Russ. J. Inorg. Chem. (Engl. Transl.) 1983 28 9; (b)A. B. Myasoedov L. N. Nikolenko and L. D. Shustov ibid. 1982 27 892. F Cl Br I At and Noble Gases 147 to monopole-allowed shake-up transitions. The calculated energy of the KrF2 ground state is in good agreement with the experimental valence-band energies.23ff Vibra- tional broadening observed in the F 1s spectra has been correlated with the dissoci- ation energy for the reaction XNe+ + X+ + Ne X = KrF XeF etc. enabling relative Lewis acidities towards Ne to be obtained.23b XeF reacts with NF4HF2 in anhydrous HF to give NF,XeF which undergoes laser photolysis at 488 nm giving (NF4),XeFs.The vibrational spectra of both compounds and those of the Cs+ salts have been obtained and evidence for the existence of NaXeF has been AH; for NF,XeF,(s) is calculated to be -490.7 kJ mol-' from a DSC study of its decomposition and the compound is by far the most energetic of known NF,+ salts.,,' Further spectroscopic information has been published on Xe[N(SO,F),] which as was reported last year contains Xe-N bonds. The data include "N n.m.r. measurements and a low-temperature Raman The chemistry of radon has been reviewed including the formation of clathrate compounds simple and complex fluorides solutions of ionic radon redox properties of Rn compounds and the unsuccessful attempts to prepare an oxide and halides other than the fluoride.26 4 Hydrogen Halides A new model for the self-association of HF vapour in the temperature range 299-329 K has been proposed from a re-examination of previously obtained P-V-T data.27 It consists of monomer trimer and hexamer species; the model differs somewhat from one reported in last year's Report which included species up to (HF),,.A new structural model for liquid HF has been proposed from a study in which the experimental vibrational spectra of HF DF and their mixtures were compared with spectra calculated on the basis of various hypothetical structures. The best fit for HF at 293 K is with a zigzag chain containing six or seven molecules having an angle of 42" with the average axis. Near to solidification at 190K eight-molecule chains with an angle of ca.35" are proposed.28 A third approach to the structural chemistry of HF is illustrated by a matrix isolation study using FT i.r. spectroscopic analysis.29 Co-condensation of HF and Ar at 12 K results in a number of bands in addition to that ascribed to the HF monomer. The different growth behaviour observed on sample warming coupled with experiments involving HF-DF mixtures enable convincing assignments to be made. Species identified include (HF) (6) for which (7) is the more stable isotopomer in the HF-DF system in agreement with previous microwave work and (HF) for which an open trans structure (8) is suggested. Open and cyclic (HF) and cyclic (HF) (n = 5 or 6) are probably present also. 23 (a) G. M. Bancroft D. J. Bristow J.S. Tse and G. J. Schrobilgen Znorg. Chem. 1983,22,2673; (b)D. J. Bristow and G. M. Bancroft J. Am. Chem. Soc,1983 105 5634. 24 (a)K. 0.Christe and W. W. Wilson Znorg. Chem. 1982,21 4113; (b)K. 0.Christe W. W. Wilson R. D. Wilson R. Bougon and T. Bui Huy,J. Fluorine Chem. 1983 23 399. " G. A. Schumacher and G. J. Schrobilgen Znorg. Chem. 1983 22 2178. 26 L. Stein Radiochim. Acta 1983 32 163. 27 J. M. Beckerdite D. R. Powell and E. T. Adams Jr. J. Chem. Eng. Data 1983 28 287. 28 B. Desbat and P. V. Huong J. Chem. Phys. 1983 78 6377. 29 L. Andrews and G. L. Johnson Chem. Phys. Lett. 1983 96,133. J. M. Winjield (6) (7) (8) 1.r. spectroscopy has made a significant contribution to our knowledge of hydro-gen-bonded base...HX (X = F C1 or Br) complexes both in the gas phase and in matrix-isolated species and recent progress has been re~iewed.~' Results obtained from Ar-matrix isolation studies are complementary to those from gas-phase work using other techniques e.g.FT microwave spectroscopy (see 198 1 and 1982 Reports) but in addition to 1 :1 complexes base.-.(HX) species are often observed on warming the matrix to ca. 20 K. Thus the species base...(HF) (base = N2 OC or H20),31a*b,c MeCN...(HX) (X = For C1) and MeCN.-(HF),3'd have been observed. Open structures are postulated for the base...(HX) complexes. The isomers (9) and (10) are both produced when HCN and HF are co-condensed with Ar at 12 K.32 H-F H-CE N--H-F H \ C* N The proportion of (9) increases at the expense of (10) on warming to 20 K in agreement with it being the more stable isomer.It is linear as has been previously shown in the gas phase but the other isomer may be non-linear. Only one isomer analogous to (9) appears to be formed from HCl and HCN under similar conditions. The complex CO--HF has not so far been observed although its C-bonded isomer is well established both in the gas phase and in a matrix (cf ref 3 1b). Theoretical work suggests that its energy is >400cm-I above that of OC.-.HF as a result of differences in electron-correlation energies.33 Hg. -HCl has been observed in the gas phase using FT microwave spectroscopy. The Hg...Cl distance is 4.097 % from which a van der Waals radius for Hg of 1.99 8 has been derived.34 This is within the range previously proposed from crystallographic work.5 Oxo-compounds Recent progress in the chemistry of inorganic and organic fluorinated hypofluorites and hypochlorites has been reviewed,35 and a new addition to this type of compound is TeF,OF prepared from FOS02F and CST~F,~.~~ ["F]MeC(O)F prepared in situ 30 A. J. Barnes J. Mol. Struct. 1983 100 259; L. Andrews ibid. p. 281. 31 (a)L. Andrews B. J. Kelsall and R. T. Arlinghaus J. Chem. Phys. 1983,79 2488; (b)L. Andrews R. T. Arlinghaus and G. L. Johnson ibid. 1983 78 6347; (c)L. Andrews and G. L. Johnson ibid. 1983 79 3670; (d)G.L. Johnson and L. Andrews J. Phys. Chem. 1983,87 1852. 32 G. L. Johnson and L. Andrews J. Am. Chem. SOC.,1983 105 163. 33 M. A. Benzel and C. E. Dykstra Chem.Phys. 1983 80 273. 34 E. J. Campbell and J. A. Shea J. Chem. Phys. 1983,79 4082. 35 J. M. Shreeve Ado. Znorg. Chem. Radiochem. 1983 26 119. 36 C. J. Schack W. W. Wilson and K. 0. Christe Inorg. Chem. 1983 22 18. F Cl Br I At and Noble Gases 149 from ''FF and NaOC(0)Me in glacial acetic acid has been used to prepare labelled 2-fluoro-2-deoxy-~-glucose~~ ref 20b). (cf Compounds containing the -OF group are often stated to be sources of 'positive' fluorine. The evidence for this in the light of recent synthetic work involving these compounds has been evaluated and found wanting.3Mu For example the products obtained from reactions between CF30F and simple alkenes suggest that the reac- tions occur via free-radical rather than by electrophilic syn-addition mechani~rns.~~ Rates of formation of N-bromoamines from OBr-or HOBr and various nitrogeneous compounds at pH 7-1 3 have been determined by stopped-flow methods.In the mechanism suggested HOBr and OBr- react simultaneously with the free amine base with electrophilic attack at N.39a The reaction of HOCl with NHC12 in aqueous solution to give NCI is base-catalysed the base assisting removal of H+ from NHC12 as the N attacks the C1 atom of HOC1. Additional HOCl is generated from the reaction between NC1 and NHCI2. The overall reaction of NHC12 is inhibited by NH3 because of preferential reaction between NH3 and ~0~1.3~~ The i.r. spectrum of matrix-isolated CsClO shows the presence of tridentate interaction between Cs+ and C103-.40 Anhydrous Zn(CIO,) appears from its vibra- tional spectrum to be polymeric and to contain bridging tridentate CIO groups.The compound is prepared by the thermal decomposition of orange C102Zn(C10,), which in turn is prepared from Zn and C1206.41 The Raman specta of KX04 (X = C1 or Br) in anhydrous HF show that both ions are partially protonated. HBrO has six times the acid strength of HCIO,; its dissociation constant in aqueous solution is estimated to be and its Hammett acidity function is estimated as ca. -13.8.42 H5106 1 mol dm- in conc. H2S04 has been used in a one-pot synthesis of C616 from C,H,; C6H5103 is a possible intermediate.43 The compound C10N02 continues to attract considerable attention no doubt in part due to its relevance in stratospheric chemistry.Mention of a possible reaction between CION02 and C12 to give C13+ has already been made." The kinetics of the reaction CI' + C10N02+CI2 + NO3' have been re-investigated. The reaction occurs about 50-times faster than was previously Three groups have independently established that the major U.V. photolytic decomposition of C10N02 gives CI' and NO3' as primary products.44",'*d The far-i.r. torsional spectrum of C1ONO2 has been re-examined at very high resolution and is interpreted in terms of a single planar r~tamer.,~ This is in agreement with the microwave study and with some of the previously reported vibrational spectroscopic studies. Evidence 37 M. Diksic and D. Jolly Inf. J. Appl. Radiaf. fsof. 1983 34 893. 38 (a)K.0.Christe J. Fluorine Chem. 1983,22,519;(6) K. K. Johri and D. D. DesMarteau J. Org. Chem. 1983 48 242. 39 (a)J. E. Wajon and J. C. Morris Inorg. Chem. 1982 21 4258; (b)V. C. Hand and D. W. Margerum ibid. 1983 22 1449. 40 1. R. Beattie and J. E. Parkinson J. Chem. SOC. Dalton Trans. 1983 1185. 4' J.-L. Pascal J. Potier and C. S. Zhang C. R. Hebd. Seances Acad. Sci. Ser. 11 1982 295 1097. 42 L. Stein and E. H. Appelman Inorg. Chem. 1983 22 3017. 43 L. S. Levitt and R. Iglesias J. Org. Chem. 1982 47 4770. See also D. L. Mattern ibid. 1983 48 4772. 44 (a)J. J. Margitan J. Phys. Chem. 1983 87 674; (b)M. J. Kurylo G. L. Knable and J. L. Murphy Chem. Phys. Leu. 1983 95 9; (c)W. J. Marinelli and H. S. Johnston ibid. 1982 93 127; (d)H.-D. Knauth and R.N. Schindler 2. Nafurforsch. Ted A 1983 38 893. 45 K. V. Chance and W. A. Traub J. Mol. Spectrosc. 1982 95 306. 150 J. M. Winjield for the presence of ClOONO in ClONO, prepared from Cl20 and N205 or by the gas-phase reaction of C10 with NO2 comes from a matrix isolation i.r. Gas-phase U.V. photolysis of C102 at room temperature using a stainless steel reaction vessel leads to ClOClO as the major product. It is not observed however when photolysis is conducted in a Pyrex Non-photochemical reactions between 02-0,mixtures and C12 below room temperature result in ClOClO CIOz or ClOClO2 depending on the condition^.^^ 6 Structural Chemistry of Solid Complex Halides Containing Main-group Elements 19 F Magic-angle spinning n.m.r. spectroscopy is a powerful technique for investigat-ing the reaction between hydroxy-apatite Ca,(OH)(PO,) and aqueous F- ion.All types of F- crystalline amorphous or adsorbed can be determined quantitatively. The growth of a surface fluoride layer when hydroxy-apatite is exposed to F-(aq.) has been demonstrated. Samples exposed to high concentrations of F-(aq.) show a signal attributable to CaF, in addition to the fluoro-apatite signal.49" Synthetic Ca,F(PO,) can be prepared from CaF and Ca3(P04)2 1 :3 mole ratio at 1933 K.49b The compounds Tl"'MF (M = Ga In or Sc) are isostructural with VF, and have a statistical distribution of metal cations in the hexagonal lattice.50a Ba2ZnAlF9 contains octahedral ZnF and AlF groups Zn" and Al"' having a statistical distribution.Four MF6 octahedra are linked to give a 'ring' system and these are connected to give This is one of three structural types which have been found for Ba2M"M"'F9 complex fluoride^.^^' Re-examination of the In/Cl phase diagram indicates that the only mixed-valence chlorides existing between InCl and InCl are In3C14 In,Cl, and In5C19. The latter compound has the Cs,Tl,Cl structure with isolated confacial bioctahedral In"',C19 groups. The preparation of solid-state compounds by chemical transport has been reviewed. In many cases gaseous halides are involved.52" An account has also been given of the gaseous ternary chloride complexes characteristically formed by MC13 (M = Al Ga In Sc or Fe"') or by UC15.52b Many of these species are effective metal-transport agents.The reaction of Ca3As2 with CaCl, 1 :3 mole ratio produces greyish-white Ca,AsCI,. This is isotypic with Mg,NF3 and its (reversible) decomposi- tion begins at 1298 K., Complex fluorides containing Sb"' have attracted considerable attention in recent years. A wide variety of co-ordination environments is possible about Sb'l' but in all cases the lone pair appears to be stereochemically active. X-Ray crystallographic 46 S. C. Bhatia M. George-Taylor C. W. Merideth and J. H. Hall Jr. J. fhys. Chem. 1983 87 1091. 47 A. J. Schell-Sorokin D. S. Bethune J. R. Lankard M. M. T. Loy and P. P. Sorokin J. fhys. Chem. 1982 86,4653. 48 R. C. Loupec and J. Potier J. Chim. fhys. fhys. Chim. Biol. 1983 80 449. 49 (a)J. P. Vesinowski and M.J.Mobley,J. Am. Chem. Soc. 1983,1M,6191;(b)E.-D. Franz,Z. Naturforsch. Ted B 1983 38 1037. 50 (a) R. Losch Ch. Hebecker and Z. Ranft 2. Anorg. Allg. Chem. 1982,491 199; (b) T. Fleischer and R. Hoppe ibid. 1982 492 83; (c)T. Fleischer and R. Hoppe ibid. 1982 493 59. " G. Meyer and R. Blachnik 2. Anorg. Allg. Chem. 1983 503 126. 52 (a) R. Gruehn and H.-J. Schweizer Angew. Chem. Znt. Ed. EngL 1983 22 82; (b) H. Sch'afer Adv. Inorg. Chem. Radiochem. 1983 26 201. 53 C. Hadenfeldt and H. 0.Vollert 2.Anorg. Allg. Chem. 1982 491 113. F Cl Br I At and Noble Gases work reported this year is illustrated by five compounds (SbF3)3SbFs,54a KSbF2(HP04),546 M'SbF(P0,).nH20 (MI = Na n = 2 3 or 4; M' = NH4 n = and NH4Sb3Flo.s4d The monoclinic 3 1 SbF3,SbF5 adduct is formed by PF3 reduction of SbF in AsF and contains SbF6- anions located between parallel strands of (Sb3F8+)ooWithin the polymeric cation Figure 2 SbF3[Sb(3),F(6),F(8)] and Sb2F5+ [Sb(2) F( l) F(3) F(7)] units can be distinguished if only the shorter inter-atomic distances are ~onsidered.~~" SbF2+ and SbF2+ cations are considered to be present in the phosphate salts with SbF2+ and SbF2+ behaving as Lewis acids towards three HP02- and four PO:- bridging ligands respectively.The co-ordina- tion environment about Sb in KSbF2(HP04) Figure 3 corresponds to a distorted octahedron if the lone pair is included. The Sb-0(2) distance is significantly longer than the other Figure 2 (Sb3F,+) strand (Reproduced from J. Chem.Soc. Dalton Trans. 1983 619) Figure 3 Co-ordination of Sb"' in KSbF,(HPO,) (Reproduced by permission from J. Solid State Chem. 1983 46 204) The Sb"' environment in the SbF2+ salts is similar to that in Figure 3 with the substitution of the equatorial F by 0.All oxygen atoms are ligated to different Sb"' atoms giving a layer structure in which F atoms are oriented alternately up and do~n.'~'' The structure of NH4Sb3Flo contains (Sb,F,,-) layers in which Sb2F7- anions and SbF3 molecules are linked.s4d The corresponding Na+ salt contains true Sb3F,,- ions. (a)W. A. S. Nandana J. Passmore D. C. N.Swindells P. Taylor P. White and J. E. Vekris J. Chem. SOC.,Dalron Trans. 1983 619; (b)S. Hurter R. Mattes and D. Ruhl J. Solid State Chern. 1983 46 204;(c) R.Mattes and K.Holz Angew. Chem. Int. Ed. Engl. 1983 22 872 Supplement p. 1315. (d)B. Ducourant R.Fourcade and G. Mascherpa Rev. Chim. Mintrale 1983 20 314. J. M. Winfield 7 Molecular Main-group Dihalides A,X2 Halides and Related Halides Structural data recently obtained for gaseous dihalides by electron diffraction are summarized in Table 1. Table 1 Bond distances and angles for some gaseous dihalides Compound (MX,) M-X (4 n XMX (") ReJ SiCl 2.083 102.8 SiBr 2.243 102.7 SnBr 2.508 100.1 SnI 2.70 1 104.1 PbF 2.030 97.2 PbBr 2.591 99.2 PbI 2.796 100.1 SeCI 2.157 99.6 a I. Hargittai G. Schultz J. Tremmel N. D. Kagramanov A. K. Maltsev and 0.M. Nefedov J. Am. Chem. SOC.,1983 105 2895; 'A. V. Demidov A. G. Gershikov E.Z. Zasorin V. P. Spiridonov and A. A. Ivanov J. Srruct. Chem. (Engl. Transl.) 1983 24 7; L. Fernhoet A. Haaland R. Seip R. Kniep and L. Korte Z. Narurforsch Teil E 1983,38 1072. The observation of matrix-isolated HSiF was reported last year and the species has now been detected in the gas phase by its laser-induced fluore~cence.~~ Low temperature X-ray work on four A2X2 (A = S or Se; X = C1 or Br) compounds indicates that the XA-AX dihedral angles are in the range 83.9-87.4". Three different crystalline modifications exist over the group owing to different ways in which the A2X2molecules are packed.56 The dimer of SF2 has the structure SF3SF. Many different conformers are possible and the precise determination of its structure is made difficult by its ready decomposition.A combined electron diffraction microwave ab initio calculation operation has provided the best information to date. The structure proposed (1 1) contains a highly distorted trigonal bipyramidal S atom. The two S-FF, bonds differ by 0.1 A and the angles between the axial bonds and the equatorial plane are ca. 77 and 92°.57 Various aspects of borons8 and tellurium59 sub-halide chemistry have been reviewed. 55 H. U.Lee and J. P. Deneufville Chem. Phys. Lett. 1983 99 394. 56 R. Kniep L. Korte and D. Mootz Z. Naturforsch. Ted B 1983 38 1. 57 M. V. Carlowitz H. Oberhammer H. Willner and J. E. Boggs J. Mol. Struct. 1983 100 161. 58 A. G. Massey Adv. Inorg. Chem. Radiochem. 1983 26 1. 59 R. Kniep and A. Rabenau Top. Curr.Chem. 1983 111; 145. F Cl Br I At and Noble Gases 8 Silicon Halides Literature values for the heats of formation of silicon-halogen compounds have been reviewed and recommended values for the compounds SiX4-,H (X = F CI or Br; n = 0 1 2 3 or 4) Six3 Six2 and Six (X = F-I) inclusive have been given. First and second bond-dissociation energies for Six have also been evalu- ated.60 Halogen lone-pair ionization potentials in a number of Group IV tetrahalides corrected for the effects of potential and relaxation energy using the corresponding halogen core-binding energies indicate that significant (p 4 d)r bonding exists. As expected the greatest lone-pair stabilization is found in SiF4.61 The structure of SiF3BF2 has been determined by microwave spectroscopy.The Si-B bond distance is 2.027 A significantly longer than expected for a single bond and the barrier to rotation about B-Si is 9.1 1 f0.02 J mol-’.62 Penta-co-ordinated species containing Si- F bonds continue to attract attention and recent work has been reviewed.63 A compound of this type is SiF4,NH3 whose structure has been assigned as a trigonal bipyramid with NH3 axial from its matrix- isolated i.r. specmm (see 1981 Report). An identical conclusion has been reached on the basis of ab initio MO calculations. From these it appears that the electron density transferred from NH to SiF originates on the H atoms. The N atom in the adduct is more negatively charged than either N in free NH or F in SiF4,NH3.64a Spectroscopically similar adducts SiF,L (L = H20 MeOH or Me20) have also been detected by matrix-isolation i.r.spectroscopy.646 A number of five-co-ordinate compounds whose stereochemistries are intermediate between trigonal bipyramidal (tbp)and square pyramidal (sp) are known; an addition to the list is the bis(tetramethylethy1enedioxy)fluorosilane anion (12). An X-ray study of the NMe,+ salt shows that the two crystallographically independent anions present are distorted from tbp towards sp by 69.1 and 52.3% re~pectively.~~ (12) (13) (14) The X-ray structure of 1-(trifluorosily1)- 1,2,3,4,-tetrahydro- 1,lO-phenantholine shows the presence of tbp Si (13) although the presence of the chelating organic group is not evident from the compound’s electronic spectrum. A chelate ligand is present also in the analogous -BF2 compound.66 Other work in this area has involved solution spectroscopic examination of (aroyloxymethyl)trifluorosilanes(14) and related compounds.Temperature solvent substituents in the ligand the pres- ence of other ligands in solution and the substitution of -F by -Me all have an 60 R. Walsh J. Chem. SOC.,Faraday Trans. 1 1983 79 2233. 61 W. L. Jolly Chem. Phys. Lett. 1983 100 546. 62 P. R. R. Langridge-Smith and A. P. Cox J. Chem. Soc. Faraday Trans. 2 1983 79 1089. 63 V. 0.Gel’mbol’dt and A. A. Ennan Sou. J. Coord. Chem. (Engl. Transl.) 1982 8 632. 64 (a)C.J. Marsden Ynorg. Chem. 1983 22 3177; (6) B. S. Auk J. Am. Chem. SOC.,1983 105 5742. 65 D. Schomburg Z. Naturforsch. Ted B 1983 38 938. 64 G.Klebe. K. Hensen and H. Fuess Chern. Ber. 1983 116 3125. 154 J. M. Winfield effect on the ability of the =C=O group to co-ordinate to Si.67 The use of a suitable chelating ligand allows the non-equivalence of the equatorial F ligands to be demonstrated by I9F n.m.r. spectroscopy at low temperatures,68a and if free radical ligands for example those derived from ortho semi-quinones are used e.p.r. spec- troscopy can be used as a probe for the stereochemistry.68b 9 Fluoro-and Perfluorocarbon-derivatives of Nitrogen 14 N n.m.r. chemical shifts of a variety of N-F cations have been obtained and have been discussed in terms of T-and a-flu~ro-effects.~~ The e.p.r. spectrum of NF3.+ is characteristic of a trigonal pyramid angle ca. 105" the N-F bonds involving sp'.' N hybrids.Thus the species differs somewhat from the isoelectronic CF,' which is essentially tetrahedral.70 The e.p.r. spectrum of CF3N(0)0C(CH3) indicates restricted rotation of the CF3- group and thus provides additional support for the postulate that alkoxylalkyl nitroxides are less planar at N than are their dialkyl analogues." Core binding energies in ONF have been interpreted on the basis of strong hyperconjugation with N-0 .rr-bonding and weak N-F a-bonding. The HOMO of ONF, derived formally from 0 p"-orbitals is weakly antibonding and has considerable F lone-pair character. Similarly the lower energy orbital derived for- mally from the N-F a-orbitals has considerable N-0 ~haracter.~, Perfluoroalkyl-ONF compounds may be synthesized either from reactions between KF,HNF and RFOF [RF = CF3 or (CF3),CF] or CF2(OF)2,73a or by the addition of ONF to XCF=CF (X = F C1 or Br) using BF3 as a In the last type of reactions only one isomer (the anti-Markovnikov) is observed and they are rationalized in terms of the formation of CF3CFXBF2 intermediates which subsequently react with ONF,.The chemistry of CF2=NF (see 1981 and 1982 Reports) has been extended by the preparation of FS020CF2NFX (X = C1 Br or OS02F) from its reactions with XOS0,F. Reactions between CF,=NF and X (X = C1 or Br) in the presence of KF or CsF lead to CF3NXF via the CF3NF- anion and similar reactions involving RFCF=NF (RF = CF3 or C,F,) and Br have been performed in order to extend the range of fluorocarbon N-bromoflu~ramines.~~" Addition of CF3NBrF to several olefins has been dem~nstrated.~~' The reactions are highly regiospecific and the 67 A.I. Albanov L. I. Gubanova M. F. Larin V. A. Pestunovich and M. G. Voronkov J. Organomet. Chem 1983 244 5; Yu. L. Frolov T. N. Aksamentova G. A. Gavrilova N. N. Chipanina V. B. Modonov L. I. Gubanova V. M. D'yakov and M. G. Voronkov Dokl. Akad. Nauk SSSR 1982,267 646; Yu. L. Frolov M. G. Voronkov G. A. Gavrilova N. N. Chipanina L. 1. Gubanova and V. M. D'yakov J. Organomet. Chem. 1983 244 107. 68 (a)V.A. Pestunovich M. F. Larin A. I. Albanov L. I. Gubanova V. M. Kopylov and M. G. Voronkov Izu. Akad. Nauk SSSR Ser. Khim. 1983 1931; (b)A. K. Chelakov A. I. Prokofev N. N. Bubnov S. P. Solodovnikov A.A. Zhadanov and M. I. Kabachnik ibid. 1983,1037; A. K. Chekalov A. I. Prokofev N. N. Bubnov S. P. Solodovnikov and A. A. Zhdanov ibid. 1983 1184. 69 J. Mason and K. 0. Christe Inorg. Chem. 1983 22 1849. 70 A. M. Maurice R. L. Belford I. B. Goldberg and K. 0. Christe J. Am. Chem. SOC.,1983 105 3799. C. Chatgillaloglu and K. U. Ingold J. Phys. Chem. 1982 86 4372. 72 C. J. Eyermann W. L. Jolly S. F. Xiang J. M. Shreeve and S. A. Kinkead J. Fluorine Chem. 1983 23 389. 73 (a)W. Maya D. Pilipovich M. G. Warner R. D. Wilson and K. 0. Christe Inorg. Chem. 1983 22 810; (6) R.D. Wilson W. Maya D. Pilipovich and K. 0. Christe ibid. 1983 22 1355. 74 (a)S.-C. Chang and D. D. DesMarteau Inorg. Chem. 1983 22 805; (b)J. Org. Chem. 1983 48 895; (c) ihid.1983 48. 771. F Cl Br I At and Noble Gases products obtained are consistent with attack of CF3NF' at the least sterically hindered C atom. The CF3NF- anion generated in situ from KF and CF,=NF reacts with RC(0)F (R = F CF, C2F5 or CH,) to give CF,NFC(O)R and with CF2=NF to give CF,NFCF=NF If CsF is used to generate CF3NF- however the sole or major product is CF3NCF2NF resulting from a further reaction of F- with CF3NFCF=NF. This diaziridine undergoes an unusual isomerization in the presence of Fe Cr or Ni to give CF3N=NCF3.74C Mixtures of (CF3),N and SbF5 slowly eliminate CF when heated at elevated temperature and the presence of the heterocyclic cation (15) is indicated in the resulting solution by n.m.r. spectroscopy. The cation (1 5) is also obtained quantita- tively from the reaction of CF3NCF2 with SbF,.One of its hydrolysis products is (I 6) which has been characterized by X-ray ~rystallography.~~ The chemistry of halogen azides has been reviewed76 and reactions of CF3N3 with various halogen- containing oxidizers has been For example the compounds CF3NX(OSO2F) (X = F C1 Br or OSO2F)have been obtained from reactions with XOS02F and CF,NClF is formed by using C1F. 10 Halides of Phosphorus Arsenic and Antimony and their Derivatives New electron-diffraction investigations of the trigonal bipyramidal gaseous com- pounds PCl and SbCl have been made.78 In the case of PC& allowance was made for the thermal equilibrium PCl e PCl + C12.78a The bond distances obtained from the SbCl analysis are considerably closer to the values obtained from X-ray data than those determined previously.78b The primary products of the vapourization of AsCl,+AsF6- appear to be AsF and the previously unreported AsC1,F.The i.r. spectrum of the latter compound isolated in a low-temperature matrix is very similar to that of C,,,PC14F.79 Barriers to pseudo-rotational processes in a number of fluoro- and/or tri-fluoromethyl-substituted aminophosphoranes have been determined from ,'P and I3C n.m.r. line-shape analyses. values obtained are in the range 34.7 f 1.7 to 73.6 f4.2 kJ. Intramolecular hydrogen-bonding occurs between primary-amino H atoms and axial F atoms. At very low temperatures evidence for cessation of P-N rotation in F(CF,),PNMe2 was obtained the barrier being 31.4 kJ.80a The thermally 75 H.Burger R. Koplin G. Pawelke and C. Kriiger J. Fluorine Chem. 1983 22 175. 76 K. Dehnicke Adu. Inorg. Chem. Radiochem. 1983 26 169. 77 C. J. Schack and K. 0.Christe Inorg. Chem. 1983 22 22. 78 (n) B. W. McClelland L. Hedberg and K. Hedberg J. Mol. Strut. 1983,99 309; (b) L. S. Ivashkevich A. A. Ischenko V. P. Spiridonov T. G. Strand A. A. Ivanov and A. N. Nikolaev J. Struct. Chem. (Engl. Transl.) 1982 23 295. 79 F. Clam and R. Minkwitz 2. Anorg. Allg. Chem. 1983 501 19. 8o (a) R. G. Cavell S. Pirakitigoon and L. Vande Griend Inorg. Chem. 1983 22 1378; (b) L. Vande Griend and R. G. Cavell ibid. 1983 22 1817. 156 J. M. Winfield unstable CH3(CF3),PH has limiting 19F and 31P n.m.r.spectra which suggest that the ground-state geometry has two axial CF3- groups as part of a trigonal bipyramidal configuration about P.'" A number of monofluorophosphoranes are capable of existing in both molecular and ionic forms; an example reported this year is Ph,PF. The ionic form Ph,P+F- in which the cation is distorted by F- is prepared from Ph4P'Br- via anion exchange and the HF2- salt. Heating the F- or HF,-salts to ca. 573 K produces molecular Ph,PF which condenses to give a second ionic form [Ph,P][ trans-Ph4PF2].81 Ph3SbC12 forms 1 1 complexes with both SbCl and SbCI,. The former involves a weak interaction between the axial C1 atoms and adjacent Sb"' atoms producing a polymeric chain structure. The latter is ionic [Ph,SbCl][SbCi,] with residual cation...anion interaction C1...SbV = 3.23 1 .$ and the cation's geometry is inter- mediate between trigonal bipyramidal and square pyramidaL8 More examples of mixed-halogenophosphonium cations and -halogenophosphate anions have been reported most often as mixtures identified in solution by n.m.r.spectro~copy.~~ In some instances salts of discrete PF,-,Cl,- anions have been isolated,83h and evidence for fluxional behavicur obtained.83'.' The water soluble adduct PF5,NH3 can be prepared either from the direct reaction between PF and NH3 or from anhydrous HF and (F2PN),. It has a slightly distorted octahedral structure its thermal decomposition at 473 K yields PF,(NH,) and it reacts with additional NH to give PF3(NH2)2.84 Prrl-Pv bonded adducts are formed between RR'P(BlOHloC2)PR''"'' (R = R' = Ph or NMe,; R = R = NMe, R = R = NMe,; R' = R = F:R = R' = Ph; R = NMe,; R'" = F) and PF which undergo F- NMe exchange reactions on thermal decomposition.In MeCN the adduct Me2N(F)P(BloHloC2)P(F)NMe2,2PF exists in the ionic form [Me2NP(Bl,H,oC2)PNMe2][PF6]2 and its thermal decomposition leads to F,P(B loH,oC2)PF2.85 The fluxional behaviour previously noted for the six-co- ordinate phosphorus carbamate Me(CF,),P02CNMe2 has been shown to be due to exchange processes catalysed by fortuitous free amine. N.m.r. studies indicate that the CF groups are equivalent in solution at room temperature and that the low-temperature solution structure of the compound corresponds to that of the solid.' Gas-phase electron diffraction studies of X(PF,) (X = S or Se) show that both molecules have average structures with C2 symmetry but have large-amplitude torsional vibrations.The electron diffraction data for PF,(SMe) are consistent with three different conformations; that which is preferred is shown in Figure4.87 The shortest F...H distance 2.51 A is slightly less than the sum of the van der Waals radii. Reaction of S(PF,)2 with hydroxy-compounds is a good route to -0PF2 derivatives the general process being represented by M-OH + " S. J. Brown and J. H. Clark J. Chem. SOC.,Chem. Commun. 1983 1256. a2 M. Hall and D. B. Sowerby J. Chem. SOC.,Dalton Trans. 1983 1095. 83 (a)K. B. Dillon and A. W. G. Platt Polyhedron 1983 2 641; (b)J. Chem. SOC.,Dalton Trans.1983 1159; (c)J. Chem. SOC.,Chem. Commun. 1983 1089. a4 W. Stoner D. Schornburg G.-V. Roschenthaler and R. Schrnutzler Chem. Ber. 1983 116 367; W. Stoner and G.-V. Roschenthaler Chem.-Zrg. 1983 107 137. 85 C. B. Colburn W. E. Hill L. M. Silva-Trivino and R. D. Verma J. Fluorine Chem. 1983 23 261. 86 R. G. Cavell and L. Vande Griend Inorg. Chem. 1983 22 2066. 87 D. E. J. Arnold G. Gundersen D. W. H. Rankin and H. E. Robertson J. Chem. Soc. Dalton Trans. 1983 1989. F Cl Br I At and Noble Gases Figure 4 Perspective views of the conformation preferred for PF,(SMe) (a) perpendicular to the P-S bond and (6) along the P-S bond (Reproduced by permission from J. Chem. SOC.,Dalton Trans. 1983 1989) S(PF2) --* M-OPF + PF2HS.P"' and Pv derivatives for example P(OPF2)388a and PO(OPF,),,R,-,, n = 3 or 2; R = F or Ph n = 1;R = Ph,886 have been prepared by this means and have been characterized by spectroscopic methods. Further work on the reaction of (CF3)2PH with ZnMe has enabled an efficient synthesis of the ylide CF3P=CF2 to be devised. The key to the synthesis is the use of Me3N as a catalyst. CF3P=CF2 is stable with respect to oligomerization as a gas at 373 K or as a liquid at 195 K.89 11 Perfluoroalkyl and Alkyl Sulphur and Tellurium Halides Fluorination of CS with F2 at low temperatures and under carefully controlled conditions is a good synthesis for CF2(SF3)2.90 The reactions of this compound are analogous to those of SF,; it reacts with AsF giving SF3CF2SF3+AsF,- and with F2 or ClF in the presence of CsF giving F,C(SF,) or ~~~~s-(C~SF,)~CF,.The electron deformation density in Me2TeC1 has been determined from high-resolution X-ray intensity measurements at 151 K. TetV bonding and lone-pair densities in accordance with the predictions of a trigonal bipyramidal AB,E (E = lone pair) model are observed and the existence of intermolecular 'secondary' bonding is confirmed." Te(CF3) can be prepared from TeC1 and Hg(CF3) at high temperature in an inert atmosphere; by-products from the reaction are CF,TeCF,Cl and Te(CF2C1),. Low-temperature fluorination of TeMe does not produce fluorinated alkyl species ; the main product is Me2TeF2.92n Oxidation of Te(CF3)2 with CI, Br, 02,or C10N02 88 (a)E. A. V. Ebsworth G.M. Hunter and D. W. H. Rankin J. Chem. SOC.,Dalton Trans. 1983 1983; 89 (b) ibid. 1983 245. A. B. Burg Inorg. Chem. 1983 22 2573. 90 A. Waterfeld and R. Mews J. Fluorine Chem. 1983 23 325. 9' R. F. Ziolo and J. M. Troup J. Am. Chem. SOC.,1983 105,229. 92 (a)S. Herberg and D. Naumann Z. Anorg. Allg. Chem. 1982 492 95; (b) ibid. 1982 494 151 159. 158 J. M.Winfield leads to the TetV compounds (CF3),TeX (X = C1 Br or NO,; X 0. Other derivatives for example where X is F or OC(O)CF, are accessible by exchange reactions involving the halides X = C1 or Br.92b 12 Sulphur Selenium and Tellurium Oxofluorides and their Derivatives CF3S02F reacts with C2F4 in diglyme and in the presence of CsF at 363-373 K to give the sulphone CF3S02C2F5.The reaction is presumed to occur uia the generation of C2F5- in situ. More surprisingly (C2F5),S02 and (C2F5),S0 are formed from the analogous room temperature reaction between SOF and CZF4. This reaction is also believed to involve C2F5- but the mechanism of the reduction step is not clear. Probably the most general route to (R,),SO compounds is the hydrolysis of (RF),SF20 which can be prepared from the corresponding sulphides by a well established route.93 The well-known anion SO2F-,SOF3- which is believed to have C symmetry and SOzF3- which is analogous to the C,,molecule C102F3 have all been generated by reactions between CsF vapour and SO2 SOF, and S02F2 the ion pairs so produced being isolated in an Ar matrix and identified by i.r. spectros- copy.94" This is a widely used technique which is very successful when CsF is used.It is less useful when other alkali-metal fluorides or CsCl are used and possible reasons for this have been Chemistry associated with the ligands OXF (X = S Se or Te) has been reviewed:," and the compounds POF2(0TeF,) OP(OTeF,), P(OTeF,), As(OTeF,), and Sb(OTeF,) have been described.95b They are prepared using Hg(OTeF,), Xe(OTeF,), or C10TeF5. Both cis-and trans-HOTeF,(OMe) react with BCl to give the analogous B[OTeF,(OMe)] compounds and these in turn can be used to prepare other derivatives for example AS[OT~F,(OM~)]~.~~~ Pyrolysis of (CF,),CS(O)C(CF,),S(O) at 723 K has led to the first example of a perfluoroalkyl sulphine (CF3),C=S=0. Its I9F n.m.r. spectrum indicates that the CF3-groups are n~n-equivalent.~~ 13 Sulphur-Nitrogen and Tellurium-Nitrogen Halides and Their Fluorocarbon Derivatives The first thiadiaziridine C2F5N-S-NC2F5 has been prepared albeit in small yield by the photolysis of C2F5N=NC2F5 with SC1 at 273 K.97 S4N4 and CIF undergo a complex series of reactions giving initially NSCl (NSCI), and NSF.NSCl reacts further to give NSF then CINSF,; the final reaction products are N, Cl, and SF,. The reaction of NSCl with ClF to give NSF and C1 can be driven in the reverse direction by adding SO2 as ClF is then removed from the system as S0,ClF. NSF is conveniently synthesized by passing NSCl through a CsF column at 383 K.98CF3SC1 reacts with Me3SiN to give (CF,SN),. This can be kept at 243 K for a few days but it oligomerizes at room temperature.CF,S(F)N=C(O)F 93 T. Imagawa G. L. Card T. W. Mix and J. M. Shreeve Inorg. Chem. 1983 22 969. 94 (a)K. Garber and B. S. Ault Inorg. Chem. 1983 22 2509; (b)B. S. Ault ibid. 1983 22 2221. 95 (a)K. Seppelt Angew. Chem. Int. Ed. EngL 1982 21 877; (b)D. Lentz and K. Seppelt Z. Anorg. Allg. Chem. 1983 502 83; (c) W. Totsch H. Aichinger and F. Sladky Z. Naturforsch. Ted B. 1983 38 332. 96 A. Elsaper and W. Sundermeyer Tetrahedron Lett. 1983 24 2141. 97 R. C. Kumar and J. M. Shreeve J. Chem. Soc. Chem. Commun. 1983 658. 98 A. J. Banister R. G. Hey J. Passmore and M. N. Sudheendra Rao J. Fluorine Chem. 1982 21 429. 159 F Cl Br I At and Noble Gases which is prepared from CF3SNC0 and F2 at 195 K reacts with HgF2 at room temperature to give (CF3SN),.99 The Lewis acid-base properties of NSF are retained when it is co-ordinated to a transition metal.Thus (OC),Re(NSF)' reacts with Me3SiNMe2 with the elimination of Me3SiF to give [(OC),Re(NSNMe,)]+ and with (Me,Si),NMe in a similar fashion giving [(OC),Re{NSN(Me)SN)Re(CO)5]2+. The ReNSN moiety in the former cation is bent.'"" (OC),Re(NSF)+ reacts with AsF to give (OC)5Re(NS)2' and AsF,-.'OOb The formation of NSON(CF3)2 from NSF and (CF,),NO was reported some time ago and the compound has now been shown to behave as a ligand towards several transition metals in +1 and +2 oxidation states.'" Oxidation of S2N+ by Cl or Br in SO leads to (SX)2N+ X = Cl or Br isolated as their AsF,- salts. An analogous reaction using XeF as oxidant and S02F2as solvent yields (F2S),N+AsF,-.The cation's symmetry is essentially C," Figure 5 Figure 5 7le (SF,),Nf cation with anion contacts (Reproduced from J. Chem. Soc. Dalton Trans. 1983 1961) and the S-N bond distances suggest a bond-order of 1.85.*02 The structure of F2SNC(0)F in the gas phase has been determined from its microwave spectrum. A single conformer is present in which N and S lone-pairs occupy cis positions (17) and the S-N bond distance 1.405A is considerably shorter than that expected for a double bond.Io3 Fe,f=N\ ,F F o4 (17) The compounds RFN=SF2 (RF = CF3 C2F5 or i-C3F7) can be methylated in SO2 to give R,(Me)NSF,+ salts and from these a variety of RdMe)N-containing com- pounds have been prepared for example R,(Me)NS(O)F RF(Me)NSF3 and CF3(Me)NSC1.104 The low temperature 1 12 K crystal structure of P~,As+N(SO~F)~- indicates that the anion has a staggered conformation of approximate C2symmetry Figure 6a.The apparently different geometry observed at 290 K Figure6b is YY D. Bielefeldt and A. Haas Chem. Ber. 1983 116 1257. 100 (a) G. Hartmann R.Mews and G. M. Sheldrick Angew. Chern. Int. Ed. Engl. 1983,22,723 Supplement p. 945; (b)R. Mews and C. Liu ibid. 1983 22 162. G. Hartmann R. Mews and G. M. Sheldrick J. Organomet. Chem. 1983 252 195. 101 I02 W. V. F. Brooks G. K. MacLean J. Passmore P.S. White and C.-M. Wong J. Chem. SOC.,Dalton Trans. 1983 1961.. I03 S. R. Bailey and J. D. Graybeal J. Mol. Spectrosc.1982 92 117. I04 H. Henle and R. Mews Chem. Ber. 1982 115 3547. J. M. Winjield Figure 6 The N(SO,F),-anion (a) af 112 K (6) at 290 K (Reproduced by permission from Acra Crystallogr. 1982 B38 2887) accounted for on the basis of two superimposed conformers which are subject to considerable thermal smearing. Low-temperature crystallography is therefore crucial in obtaining a chemically sensible structure for this compound.105 Imidodifiuorosul- phates of divalent transition-metals M(NSOF2)2 (M = Co Ni or Cu) can be obtained from [M(S02)2][AsF6]2 and R3SiNSOF2 in SO2.In two cases the reaction intermediates Cu(NSOF2)(AsF5NSOF2) and N~(SO,),[ASF,(NSOF~),]~ have been isolated and the latter's structure is shown in Figure 7.*06Hg[N(SF,)2]2 is a useful Figure 7 Molecular strucrure of Ni(S02)2[AsF,(NSOF2)2]2 (Reproduced by permission from Chem.Ber. 1983 116 874) I05 W. Isenberg M. Noltemeyer and G. M. Sheldrick Acta Crystallogr. 1982 €338 2887. I06 R. Hoppenheit R. Mews M. Noltemeyer and G. M. Sheldrick Chem. Ber. 1983 116 874. F CZ Br I At and Noble Gases 161 reagent for the introduction of -(SF,) groups. It reacts with Me1 and CF,SCl to give MeN(SF,) and CF3SN(SF5) respe~tively.'~' Compared with the large number of TeF,O- compounds which are known (see Section 12) few examples of TeF,N= compounds have been reported. However feasible routes to such compounds are beginning to emerge for example H2NTeF or Me3SiN(H)TeF are suitable starting materials for the preparation of compounds such as OCNTeF, Cl,W=NTeF, and Cl,Se=NTeF,.The X-ray crystal structure of Cl,W=NTeF shows that the W-N-Te linkage is almost linear (171") and that WCl and TeF moieties are eclipsed. It is concluded that there is some double bond character throughout the system.'Oga Irradiation of TeF,Cl and RCN (R = C1 or CF3) at room temperature gives F,TeN=CRCl. From F,TeN=CCl other deriva- tives for example F,TeN=CF, F,TeNCF3- and CF3N(TeF,), are accessible. The latter compound provides the first example of a Te-N-Te linkage.'086 14 Structural Work on Solid Hexafluorides Neutron diffraction studies have been made on polycrystalline MoF, WF6 and UF6 at 77 K completing a structural investigation of solid MF6 (M = S Mo W or U) phases. The existence of the orthorhombic &ma phase for the metal hexafluorides down to 77 K is confirmed.M-F bond lengths do not decrease significantly on cooling to 77 K but the octahedra pack more efficiently and make a closer approach to the ideal hexagonal close-packing of F atoms. MoF, WF, and especially SF are more compact and spherically-shaped molecules than UF, explaining the absence of a plastic phase in the latter and the larger temperature range over which plasticity is observed in SF6.109 The MF (M = Mo W or U) molecules in the solids show no deviation from Oh symmetry within the level of accuracy of the data. I9F N.m.r. spectra of polycrystalline UF have been cited as evidence for distortion in the molecules however in the latest interpretation it is concluded that they have Oh symmetry.' lo Molecular dynamics calculations have reached the stage where they are able to reproduce all the solid-state phase transitions in SF6 and they have been used to make suggestions about the nature of the disorder in the plastic phase." Micro-crystals of MF6 (M = S Se or Te) have been produced in nozzle flows of these gases mixed with noble gases.Their examination by electron diffraction shows that orthorhombic Pnma or cubic plastic phases are produced depending on the MF6 partial pressure and the nucleation conditions used. The low-temperature phases produced in this study differ from their metal hexafluoride counterparts in being less dense than the cubic forms."2 A detailed analysis of site symmetry effects in the i.r. spectra of SF6 or SeF isolated in noble gas solids has been made.'I3 Ordered orientation of SF in Kr is particularly pronounced but it is observed in all the systems examined (see also re$ 19c).I07 A. Waterfeld and R. Mews Chem. Ber. 1983 116 1674. 108 ((1) H. Hartl P. Huppmann D. Lentz and K. Seppelt Inorg. Chem. 1983 22 2183; (b) J. S. Thrasher and K. Seppelt Angew. Chem. Int. Ed. Engl. 1983 22 789 Supplement p. 1106. I09 J. H. Levy J. C. Taylor and A. B. Waugh J. Nuorine Chem. 1983 23 29. I10 E. P. Zeer 0.V. Falaleev and V. E. Zobov Chem. Phys. Lett. 1983 100 24. Ill G. S. Pawley and M. T. Dove Chem. Php. Lett. 1983 99 45. I12 E. J. Valente and L. S. Bartell J. Chem. Phys. 1983 79 2683. 113 L. H.Jones and B. I. Swanson 1. Chem.Phys. 1983 79 1516. 162 J. M. Winfield 15 Binary Halides of &Block Elements What may be a new hexafluoride PdF, has been reported to be the product from the reaction between Pd metal and F, passed through a high-voltage electrical discharge at 330 K. The thermally unstable solid is a strong oxidizing agent.Il4 Halogen exchange reactions of OsF, w6 and RuF result in reduction of the metal and in some cases the formation of polymeric mixed halides for example Ir2F3C16 Os,Br4F, and Ir2Br4F5.' Electronic and vibronic energy levels derived from the 12i configuration in OsF have been studied by electronic Raman scattering and absorption spectra from OsF doped in single crystal MoF or WF hosts. The first excited state TZFlies very close to the Egground state and Jahn Teller effects are observed in the TI excited state.I16 Electron diffraction studies of gaseous MoCl and WCl do not distinguish between D3, and C, structures and its seems therefore that the barrier between them is small."' By the same technique the presence of D,, (NbF,)3 has been detected in NbF vapour at 333 K."' An analogous species has been observed in TaF previously.Molten MoF appears from a study of its magnetic susceptibility to contain (MoF,), n = 3,4 or 5 chains in which the Mo" centres are antiferromagnetically coupled.' l9 A new modification of NbBr has been inadvertantly prepared by the reaction of NbBr with sulphur in a closed tube. It is isostructural with TaI, layers of (NbBr,) being stacked with displacement faults along the b direction.I2' Although several ternary fluorides containing Ag"' are known the binary fluoride had not been isolated until this year.AgF3 has been prepared as a reddish-brown paramagnetic solid from the oxidation of AgF by KrF in anhydrous HF.'" FeF3(H20)o,33,grown by hydrothermal synthesis has a Fe"'F framework related to that of the hexagonal W bronze Rbo.29W03. H20 is evolved on heating to 395 K without any noticeable change in the F skeleton so the resulting anhydrous FeF is a new modification. It transforms to the cubic-ReO type at 798 K.I2,= Red monoclinic Fe3F,,2H,0 which is also obtained by hydrothermal synthesis contains layers of [Fe"'F,,,] octahedra connected by corner-sharing to [Fe"F4,2(H,0)2].'22h a-RuC13 has a layer-type AlCl structure and various guest molecules have been intercalated using electrochemical or chemical techniques.RuBr shows similar behaviour. 23 Binary chlorides of Fe Co and Ni have been obtained in Ar-matrices from sputtering reactions of the metals in isotopxy enriched CI,-Ar atmospheres. 1.r. spectroscopy of the species indicate that ClMCl (M = Fe or Co) are greater than 120" in MCl3 as expected for planar molecules whose vibrations are somewhat I14 A. A. Timakov V. N. Prusakov and Yu. V. Drobyshevskii Russ. J. Inorg. Chem. (Engl. Transl.) 1982 27 1704. I I5 R.C. Burns and T. A. O'Donnell J. Fluorine Chem. 1983 23 1. I16 D. L. Michalopoulos and E. R. Bernstein Mol. fhys. 1982 47 I. I I7 Yu. S. Ezhov and A. P. Sarvin J. Strct. Chem. (Engl.Trans/.) 1983 24 49 140. I18 G. V. Girichev V. N. Petrova V. M. Petrov and K. S. Krasnov Koord. Khim. 1983 9 799. I19 V. N. Ikorskii and K. A. Khaldoyanidi J. Struct. Chem. (Engl. Trans[.) 1982 23 302. I2O U. Muller and P. Klingelhofer Z. Naturforsch. Teil E 1983 38,559. I21 R. Bougon and M. Lance C.R. Hebd. Seances Acad. Sci. Ser. II 1983 297 117. I22 (a) M. Leblanc G. Ferey P. Chevallier Y. Calage and R. De Pape J. Solid State Chem. 1983,47 53; (b) E. Herdtweck Z. Anorg. Allg. Chem. 1983 501 131. R. Schollhorn R. Steffen and K. Wagner Angew. Chern.. Int. Ed. Engl. 1983 22 555. F Cl Br I At and Noble Gases 163 anharmonic. The dihalides MC1 (M = Fe Co or Ni) are believed to be non-linear in contrast to some previous work.'24 Treatment of Pd3(02CMe)6 in glacial acetic acid with either HCl or CO and HC104 produces P-PdCl, Pd6ClI2 quantitatively. These are the first useful syntheses of this form.'25 A re-investigation of VCl2,2thf by X-ray crystallography has shown that the compound is actually [(thf)3VC13V(thf)3]2[C12ZnC12ZnC12], the bource of the anion being Zn metal which is used to perform the VC13 -* VC12 reduction.'26 16 Halogenometallates of the &Block Standard enthalpies of formation of solid K3MF6 (M = Sc-Cu inclusive and Ga) have been determined by solution calorimetry. The derived values of AH; from the constituent gaseous ions Kf M3+ and F- show the familiar double-humped curve when plotted against the number of M3+ 3d electrons as predicted by ligand-field theory.However the magnitudes of the humps are somewhat larger than e~pected.',~ The redox couples MF6'"-' (M = Ta W Re Os Nb Mo or Ru; z = 0 -1 or -2) have been detected in MeCN by cyclic voltammetry.'28 Analogous couples originating from 4d and 5d elements are almost uniformly separated by 1.O V the former being the more oxidizing and linear progressions in the observed E" values occur for electronic configurations up to and including d3. MoC~,~-has been identified in a basic AlCl, N-n-butylpyridinium chloride melt and its reversible reduction to MoClB- dem0n~trated.I~~ The ion was generated by dissolution of MoCI or MoC16- in the melt and the apparent instability of MoV contrasts with previous studies of MoV in basic AlCl,,NaCl melts.(Et,N)OsC16 is formed quantitatively by heating the corresponding salts of tr~ns-[OsX,(CO)~]- (X = Br or I) in C12 at 393 K. The OsC16- anion is readily reduced to osc162-.'30 Although the cell dimensions of Pb2RhF7 are similar to those of K2NbF7 its structure is different being Pb,F[RhF,] in which the RhF6 group is a distorted ~ctahedron.'~' The TaF,2- ion in solid K2TaF is fluxional and its vibrational spectrum cannot be assigned on the basis of any of the polyhedra commonly used for seven-co-ordinate compounds. At lower temperatures it adopts a rigid structure of low symmetry and the anions are stationary on the n.m.r. time scale below 150 K.l3 The trirutile LiV2F6 is a true mixed-valence compound which contains pairs of crystallographically equivalent orthorhombically distorted VF6 octahedra that share one edge.Its tem- perature-dependent magnetic susceptibility has been interpreted on this Defect structures in the hexagonal vanadium bronzes A,VF3 (A = K Rb Cs or TI; 0.18 S x G 0.32) have been observed by electron I24 D. W. Green D. P. McDermott and A. Bergman J. Mol. Spectrosc. 1983 98 11 1. I25 A. Yatsimirski and R. Ugo Inorg. Chem. 1983 22 1395. I26 F. A. Cotton S. A. Duraj M. W. Extine G. E. Lewis W. J. Roth C. D. Schmulbach and W. Schwotzer J. Chem. SOC. Chem. Commun. 1983 1377. 127 P. G. Nelson and R. V. Pearse J. Chem. SOC.,Dalton Trans. 1983 1977. 128 S. Brownstein G. A. Heath A. Sengupta and D. W. A. Sharp J. Chern. SOC.,Chem. Commun. 1983,669. 129 T. B. Schemer C. L.Hussey K. R. Seddon C. M. Kear and P. D. Armitage Inorg. Chem. 1983,22,2099. 130 W. Preetz and M. Bruns Z. Naturforsch. Ted B 1983 38 680. 131 R. Domesle and R. Hoppe Z. Anorg. Aflg. Chem. 1983 501 102. I32 R. B. English A. M. Heyns and E. C. Reynhardt 1. Phys. C. 1983 16 829. '33 (a)R. M. Metzger N. E. Heimer C. S. Kuo R. F. Williamson and W. 0. J. Boo Inorg. Chem. 1983 22 1060; (b)D. Rieck R. Langley and L. Eyring J. Solid State Chem. 1983 48. 100. I64 J. M. Winjield New fluoropalladates( 11) reported this year include orange-brown CsPd2FS in which Pd" has both octahedral and planar environments.'34a Evidence for Pd"' in NaPdF comes from an e.p.r. study. The compound's structure is derived from the KBrF type but the low spin Pd"' environment is axially A compound which has a related structure is CsCuF,.It contains the first example of diamagnetic Cu"' in a square planar en~ir0nment.I~~' Although CuF has not been isolated Cu' is stable as a dilute solid solution in NaF due to the favourable heat of solution of Cu' as compared to Cu2+ and Cu and to a favourable entropy of mixing. One- and two-photon polarized spectroscopic studies of the 3d lo--* 3d94s transition have been made and a Jahn-Teller effect ~bserved.'~' The low temperature S443 K crystal modification of CsAgCl contains cubically co-ordinated Cs' and trigonal- bipyramidally co-ordinated Ag+. The compound reacts with C12 to give black CsAgCI,, (x = ca. 0.125) with essentially the same str~cture.'~~ The reaction between AgF and UF in anhydrous HF yields an insoluble solid analysing as Ag,UF8.However the solid has unexpected oxidizing ability and it could be a mixture containing AgF and Ag1UVF6.'37 17 Oxohalides Chalcogen-halides and Oxohalogenometallates of d Block Elements The structure of CrO,F in the gas phase has been re-investigated by electron diffraction and its quadratic force-field determined.I3* The structural parameters obtained are in a harmony with those reported last year for Cr02C12. Cooling VOC13 below its m.p. 196 K produces a yellow amorphous phase which transforms to an orange orthorhombic phase on further cooling. Low temperature X-ray crystallogra- phy and 35Cl n.q.r. spectroscopy show that the orthorhombic phase comprises VOC13 molecules C symmetry stacked to form trigonal prismatic columns Figure 8.Intramolecular bond distances and angles are very similar to those determined for the gas phase and the overall structure of the solid is more closely related to those of POC13 and Main-Group V trihalides (see 1982 Report) than to other transition- metal oxotrihalides. 139 The i.r. and electronic spectra of matrix isolated WSX, and WSeX (X = F C1 or Br) have been observed and assignments made on the basis of C, The crystal structures of MSF (M = W or Re) which are prepared in high yield from reactions of MF6 with sulphur at 573 K contain cis-F bridged polymers. The adduct WSF,,NCMe is monomeric.'40b Treatment of NbSX3 (X = C1 or Br) with tetrahydrothiophene (tht) gives NbSX3,2tht as the initial products but complex redox-disproportionations occur subsequently yielding [(tht),XzNb(pS2)(p-I34 (a)B.G. Muller Z. Anorg. Allg. Chem. 1982 491 245; (b)A.Tressaud S. Khairoun J.-M. Dance J. Grannec G. Demazeau and P. Hagenmuller C. R. Hebd. Seances Acad. Sci Ser. ZZ 1982 295 183; (c)T. Fleischer and R. Hoppe 2. Anorg. Allg. Chem. 1982 492 76. S. A. Payne A. B. Goldberg and D. S. McClure 1. Chem. Phys. 1983 78 3688. I36 H.-C. Gaebell G. Meyer and R. Hoppe Z. Anorg. Allg. Chem. 1983 497 199. 13' J. G. Malm J. Fluorine Chem. 1983 23 267. I38 R. J. French L. Hedberg K. Hedberg G. L. Gard and B. M. Johnson Inorg. Chem. 1983 22 892. I39 J. Galy R. Enjalbert G. Jugie and J. Strahle J. Solid Stare Chem. 1983 47 143. I40 (a)P. J. Jones W. Levason .I.S.Ogden J. W. Turff E. M. Page and D. A. Rice J. Chem. SOC.,Dalton Trans. 1983 2625; (b)J. H. Holloway V. KauEiE and D. R. Russell J. Chem. SOC.,Chem. Commun. 1983 1079. F Cl Br I At and Noble Gases 165 Figure 8 Perspective view close to the (001) ptane of the molecular packing in VOCI (Reproduced by permission from J. Solid Stare Chem. 1983 47 143) S)NbX,(tht),]. In the adduct Nb=S is trans to one tht ligand and the Nb'V...NblV distances in the final dinuclear products indicate a single metal-metal intera~ti0n.I~' Recent investigations of oxofluorometallates have a structural bias X-ray crystal- lography being the most popular technique supplemented when disorder exists by vibrational spectroscopy. Anions that have been examined in this way include those of~V142a vIV 142b Vv or VIV doped into MoV1oxofluorometallates,142"and WV1.142c Cs3[V204F5] in which the Vv atoms are statistically disordered over all (0,F) octahedral exhibits a weak red emission at low temperature^.'^^ y-Irradi-ation of (NH4)3V02F4 results in an e.p.r.spectrum which is assigned to the trans-(V02F4)4- anion,I4" and the corresponding Vv anion has been identified by "V and '9Fn.m.r. spectroscopy in acidified aqueous solutions of Na( NH4)2V02F4.'44b V205 in 48% aqueous HF has an identical spectrum although the species formed in this solution was previously believed to be VOF,-. Solid products obtained from the thermal decomposition of (NH4)3W02F5are believed to be oxofluoride tungsten bronzes in which NH4+ H2F+ and H30+ cations occupy interstitial positions.145 Numerous compounds of the type A2MOX (A = K Rb or Cs; M = Cr Mo W Tc or Re; X = C1 or Br) have been claimed in the literature but a careful preparative study indicates that not all can be isolated in a pure state.Solubilities redox stabilities and tendencies to undergo disproportionation are all im~0rtant.I~~ The reaction between NbCI5,NbOCI3 and PhCrCPh in CH2C12 leads to dark green [Ph4C4C1][Nb20CI,]. The Nb-0-Nb linkage in the anion is almost linear 174" and two anions are linked by asymmetric C1-bridges to give a centro-symmetric dimer [C1sNbONbC13C12,2]22-.147 141 M. G. B. Drew D. A. Rice and D. M. Williams J. Chem. SOC.,Dalton Trans. 1983 2251. I42 (a)R. Mattes and H. Forster J. Less-Common Met.1982 87 237; (b)J. Solid Stare Chern. 1982 45 154; J. Mazicek V. K. Tranov and L. A. Aslanov Koord. Khirn. 1982 8 1550; (c) R. Dornesle and R. Hoppe 2. Anorg. Allg. Chem. 1982 492 63; W. Massa S. Hermann and K. Dehnicke ibid. 1982,493 33; R. Mattes and H. Forster ibid. 1982 494 109. 143 G. Blasse and G. J. Dirksen 2. Natttrforsch. Teil B 1983 38 788. 144 (a) U. R. K. Rao K. S. Venkateswarlu B. R. Wani M. D. Sastry A. G. I. Dalvi and B. D. Joshi Mol. Phys. 1982 47 637; (b)R. J. Gillespie and U R. K. Rao J. Chem. Soc. Chem Commun. 1983 422. I45 E. G. Rakov E. I. Mel'nichenko and S. A. Polishchuk Russ. J. Znorg. Chem. (Engl. Trans/.) 1983 28 138. 146 J. E. Fergusson A. M. Greenaway and B. R. Penfold Inorg. Chim. Acta 1983 71 29. 147 E.Hey F. Weller and K. Dehnicke 2. Anorg. Alfg. Chem. 1983 502 45. J. M. Winfield 18 Actinide Halides The electron affinity of UF6 has been determined to be 5.50 * 0.3 eV by an effusion mass spectrometry method this value being in good agreement with a previous I.C.R. determinati~n.'~~ From a re-investigation of its valence electron spectrum it has been suggested that the HOMO of UF has t, symmetry a similar situation to that in SF, MoF, and WF, rather than t, as has been generally assumed.'49 Photodissociation of PuF at 337 nm appears to yield PuF5 but its existence under these conditions is only transitory and further dissociation occurs giving PuF4.1So UF5 has a much longer lifetime under similar conditions (See 1981 Report). Reduc- tion of UF6 by PF is a convenient synthetic route to P-UF5,15' and good evidence for the series of mixed halides UF,-,CI (n = 1-5) has come from a low tem- perature i.r.study of reactions between UF and BC13 or TiCl in liquid Xe.19' Bands attributable to all members except trans-UF4C12 were observed. A detailed thermochemical study of the reactions 2AX(c) + ThX,(c) = A2ThX,(c) (A = K or Cs; X = C1 or Br) has been carried out and enthalpies of formation of MX,2-(g) (M = Th or U) and the two-halide ion affinities of MX4 cal~ulated.'~~ A number of structural investigations of lower oxidation-state halides and their com- plexes have appeared.'53 Np,F 2rH20has a three-dimensional network structure in which NpF (tricapped trigonal prism with two corners missing) and NpFs (bicapped trigonal prism and antiprism) polyhedra can be distinguished.H20 molecules are located in lattice 'holes' at 2.54 and 2.43 8 from Np; Np-F are 2.18-2.78 A.153a NaNp,F ,is structurally related to CsU,F2 and contains NpF tricapped trigonal prisms in which Np-F are 2.288-2.55 A."" Solid AmI has two phases the transition point being 673 * 30 K. The low temperature orthorhombic phase is of the PuBr type; the high temperature hexagonal phase has the BiI structure. They can be distinguished from their electronic absorption spectra and are prepared from 243Am with I2 at 573 K and from 243Am02 with HI above 873 K respectively. Reaction of 243Am13 with moist HI above 823 K leads to 243AmOI which has the PbClF K2UC15 has a chain structure based on monocapped trigonal prisms linked via two common edges [UC13C12/2C12/2].153d A consideration of lattice constants and molar volumes suggests a close relationship between U'"-Cl com-pounds and their Ce"' analogues,'53d and a similar conclusion has been drawn from a study of CeCl complexes compared with their U'" counterpart^.'^^ Anodic oxidation of Th metal into a solution of I2 in MeCN allows the isolation of Th12,2MeCN from which ThI [alternatively formulated as Th4+(e),I,] is easily obtained.The method is more convenient than the alternative high-temperature synthesis.155 I48 A. T. Pyatenko A. V. Gusarov and L. N. Gorokhov Russ. J. Phys. Chem. (Engf. Transl.) 1982,56 1164. I49 N. Mirtensson P.-A. Malmquist and S. Svensson Chem. Phys.Len. 1983 100 375. Iso K. C. Kim and G. Campbell Chem. Phys. Len. 1983 98 491. 151 T. A. O'Donnell R. Rietz and S. Yeh J. Fluorine Chem. 1983 23 97. IS2 A. D. Westland and M. T. H. Tarafder Can. 1. Chem. 1983 61 1573. IS3 (a)A. Cousson H. Abazli M. Pages and M. Gasperin Actn Crysrallogr. 1983 C39,425; (b)ibid. 1983 C39 318; (c)R. G. Haire J. P. Young and J. R. Peterson 1.Less-Common Mer. 1983 93 339; (d)G. Meyer H.-Chr. Gaebell and R. Hoppe ibid. 1983 93 347. I54 J. Barry J. G. H. du Preeze T. I. Gerber A. Litthauer H. E. Rohwer and B. J. van Brecht J. Chem. SOC.,Dalton Trans. 1983 1265. 155 N. Kumar and D. G. Tuck Inorg. Chem. 1983 22 1951. F Cl Br I At and Noble Gases 167 19 Lanthanide Halides He' PE spectra of several gaseous LnX (Ln = La Ce Nd Er or Lu; X = C1 Br or I) have been reported together with Xa calculations and comparisons with previous related work on the fluorides.Early members of the lanthanide series have 4f-like ionizations at lower energies than the ligand p-like orbitals but this situation is reversed for later members. Fluorides show predominantly ionic bonding covalent character increasing with increasing mass of the halogen. 156 The X-ray crystal structure of [N(C6H,CH3)Et3]2[CeC16] shows a distorte%tahe- dral CeC1,2-anion in which Ce-Cl = 2.594-2.619 A and ClCeCl = 88.25-90.50°.'57" Although CeC162- decomposes readily at ambient temperature in many solvents it appears to be stable indefinately in SOC12.1s4 Photoreduction occurs in MeCN at all wavelengths corresponding to the charge-transfer bands of CeC162-.The process involves loss of C1' after direct transfer of an electron from ligand to Decomposition of CeC1,2- salts having Nk' and related cations occurs at moderate temperatures but C12 is not always observed as a product.'s7' The electron affinity of CeF, determined by an effusion mass spectrometric method is as expected relatively large 3.6 f 0.3 eV."* The compounds A,LnF7 (A = Group 1 cation; Ln = Ce Pr or Tb) have the (NH3)3ZrF7 structure. These and other Ln'" complex fluorides of the A,LnF or A'LnF (A' = Group I1 cation) types can be prepared by high temperature fluorination^.'^^ Reactions involving Xe fluorides or KrFz are an alternative synthesis.2' Reduction of LnF by Cs or Rb metals has resulted in the isolation of the cubic perovskites CeEuF (yellow) CsYbF (bright green) and RbYbF (orange).',' Reduction of GdI by Gd metal and graphite at 1170 K produces GdI2C6II7.This compound contains Gd6II2 clusters linked via trans edges of the Gd6 octahedra to give linear trimeric units which are further linked via cis edges forming zigzag chains. C2 units are located at the centres of the Gd octahedra.'6' A well-resolved i.r. spectrum of matrix-isolated YbC12 has been obtained and from this the 6Cl angle has been estimated to be 126 f5°.162 20 Graphite-Halide Intercalation Compounds and Graphite Fluorides Intercalation of halogens and halides continues to be widely studied. Recent results and references to the earlier review literature are contained in two reviews dealing with graphite intercalation corn pound^.'^^ One of the most interesting developments this year is the demonstration of F2 intercalation which has been reported by two '56 B.RuSEiC G. L. Goodman and J. Berkowitz J. Chem. Phys. 1983 78 5443. 157 (a) V. M. Agre and Yu.M. Kiselev Russ.J. Inorg. Chem. (Engl. Transl.) 1983,28,334; (b)L. L. Costanzo S. Pistara and G. Condorelli J. Photochem. 1983 21 45 (c)Yu. M. Kiselev and A. I. Popov Russ. J. Inorg. Chem. 1983 28 190. Is* E. B. Badtiev N. S. Chilingarov M. V. Korobov L. N. Sidorov and I. D. Sorokin High Temp. Sci. 1982 15 93. I59 K. Feldner and R. Hoppe Rev. Chim. Minirale 1983 20 351. 16V G.-Q. Wu and R. Hoppe Z. Anorg. Allg. Chem. 1983 504 55.161 A. Simon and E. Warkentin 2. Anorg. Allg. Chem. 1983 497 79. I62 1. R. Beattie J. S. Ogden and R. S. Wyatt J. Chem. Soc. Dalton Trans. 1983 2343. I63 N. Bartlett and B. W. McQuillan in 'Intercalation Chemistry' ed. M. S. Whittingham and A. J. Jacobson Academic Press New York and London 1982 Chapter 2 p. 19; W. C. Forsman and T. Dziemianowic Synthetic Metals 1983 5 77. 168 J. M. Winjield groups.'64 In one case the reaction occurs ca. 293 K in the presence of anhydrous HF to yield first stage C,F (5 > x > 2) via the second stage compound C12+HF2-.164n In the other study C,F (x > 2) were prepared by exposing HOPG to F2 gas with catalytic quantities of AsF, IF5 or OSF,.'~~' In both cases the products are distinct from the known covalent graphite fluorides (see below) and in one very highly conducting materials were obtained.The identity of the intercalated species has not yet been established. Semi-ionic C-F bonding has been postulated,'64* and mobile F2 is another po~sibility.'~~' Intercalation of Br in graphite was first demonstrated many years ago but the identity of the resulting intercalated species is still not established with certainty. In one of several recent X-ray structural studies the presence of interacting Br4"- units having interatomic distances comparable to those in known polybromide anions has been po~tulated.'~~ Intercalation of S206F2 into various types of graphites has been reinvestigated. A rearrangement occurs shortly after intercalation presumably to give S03F-.The maximum degree of intercalation achieved corresponds to C7S03F and electrical conductivity reaches a maximum ca. C I 2-16S03F.166a C8S03F undergoes irreversible solvolysis in CF,S03H to give C12S03CF3 whose spectra support an ionic formula- tion,'666 and in liquid SbF5 to give C8+SbF6- in quantitative yield.166c Both reactions have counterparts in conventional inorganic chemistry. Intercalation of SbC15 in graphite leads to compounds in which both Sb" and Sb"' are present. In a model deduced for the intercalate layer from an X-ray diffraction Sb" atoms are located on a mirror plane at the layer's centre and are flanked by Sb'" layers with C1 layers contacting the boundary C layers. Raman spectroscopy is useful for investigating these compounds and the use of this technique applied to a dilute first stage SbC15 intercalate suggests that species formally related to SbCl, SbCl,,- SbC163- and SbC16- are present.'67b Raman spectroscopy can also be usefully applied to monitor the course of the intercalation process.16" Although SbC15 intercalated graphites are often regarded as being air-stable (e.g. ref 167a) changes do occur in the first stage compound on exposure to air for example de-intercalation with subsequent hydrolysis and the formation of higher- staged compounds.167b Similar phenomena have been documented for FeC1,- graphites indicating that for these materials also the assumption of air stability is unjustified. FeC1,-intercalates obtained by H2 reduction of Fe"' precursors are even more air sensitive.'68a The covalent graphite fluoride (C,F) is now recognized as a chemical entity which is distinct from covalent (CF), and it can be formed by the reaction of Fz I64 (a)T.Mallouk and N. Bartlett J. Chem. Soc. Chem. Commun. 1983 103; (b)1. Palchan D. Davidov and H. Selig ibid 1983 657. 165 D. Ghosh and D. D. L. Chung Muter. Res. Bull. 1983 18 1179. 166 (a)J. G. Hooley Carbon 1983 21 181; (b)S. Karunanithy and F. Aubke ibid. 1982 20 237; (c)J. Nuorine Chem. 1983 23 541. 167 (a)M. H. Boca M. L. Saylors D. S. Smith and P. C. Eklund Synthetic Metals 1983 6 39; (b)W. Jones P. Korgul R. Schlogl and J. M. Thomas J. Chem. SOC.,Chem. Commun. 1983,468; J. M. Thomas R. Schlogl W. Jones and P. Korgul Carbon 1983 21 409; (c) R.Schlogl W. Jones and J. M. Thomas J. Chem. SOC.,Chem. Commun. 1983 1330. I68 (a)R. Schlogl P. Bowen G.R. Millward and W. Jones J. Chem. SOC.,Faraday Trans. I 1983 79 1793; (b)S. E. Millman Synthetic Metals 1983 5 147. F Cl Br I At and Noble Gases with heat-treated petroleum coke between 610 and 733 K.1690 The reaction between F2 and the intercalation compound formed from graphite and AlF3 in the presence of F is an alternative synthesis;169b in both cases the content of (C,F) in the total graphite fluoride products are >60%. Both (C,F) and (CF) are used commercially as cathode materials in lithium batteries and their electrochemical properties have therefore received considerable attenti~n.'~' Their discharge characteristics in several non-aqueous solvents have been investigated dimethyl sulphoxide being the best of those examined.It is believed that solvated Lif is intercalated into the graphite fluoride layers by the electrode reaction and the total cell reaction may be represented by C,F + Li + zS- C,y(Li+ zS)F- (where S = solvent m~lecule).'~' Formation of a surface layer of graphite fluoride on the carbon anode during the electrolysis of molten KF,2HF is generally believed to be responsible for the high anodic overpotential for F2 ev~lution.'~' Supporting evidence for this contention is provided by mass spectrometric analyses of thermal decomposition products of graphite fluorides compared with anode materials. The anode surface layer is estimated to have the approximate composition CFI (a) N.Wantanabe Y. Ashida and T. Nakajirna Bull. Chem. SOC.Jpn. 1982,55,3197; (6) N. Watanabe T. Nakajima M. Kawaguchi and A. Izumi ibid. 1983 56 455. I70 N. Watanabe J. Fluorine Chem. 1983 22 205. 171 N. Watanabe R. Hagiwara T. Nakajima H. Touhara and K. Ueno Electrochim. Acra 1982 27 1615. 172 D.Devilliers M.Vogler F. Lantelme and M. Chemla Anal. Chim. Acta 1983 153 69.

ISSN:0260-1818    

DOI:10.1039/IC9838000143

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

Ti Zr Hf; V Nb Ta; Cr,Mo W; Mn Tc Re By J. E. NEWBERY Department of Chemistry University of London Goldsmiths’ College New Cross London SE 14 6NW 1 Introduction Section 7 attempts to present some of the more interesting and important pieces of work published on the chemistry of the early transition metals. One of the fascinating aspects of review work is the sudden appearance of a whole new area of development. Such a situation arose in the late 70s when the chemistry of metal-metal bonds really underwent expansion with publications rapidly increasing from the rate of ca. 20 per annum to the current level of around 100. A good readable chronicle of this area has recently been presented.’ 2 Titanium Zirconium and Hafnium A photoelectron spectroscopic investigation into ZrH,,, ZrXH0.5 and ZrXH (X = C1 or Br) has indicated substantial Zr-H covalency,2 and that no major differentiation should be made between the nature of hydrides and that of other binary compounds.The zirconium monohalides ZrCl and ZrBr have novel layered structures with a stacking sequence X-Zr-Zr-X. Reaction between the halide and Zr02 has been shown3 to follow the equation ZrX + nZrO = ZrXO,. + nZrO with x and y up to about 0.4. The basic crystal framework is unchanged by this reaction and the oxygens are randomly distributed between the zirconium layers. The monohalides were also shown to be resistant to intercalation of small molecules. Cs2TiC1,.4H20 has been shown4 by single-crystal X-ray diffraction analysis to contain tr~ns-[TiCl~(H~O)~]+ ions.The compound has an ill-defined shoulder in the electronic spectrum at 10 K which may be indicative of this trans configuration. A series of titanium P-diketonate complexes has been studied’ by n.m.r. spectros- copy. For the complexes shown in (l) with R = Pri Bu’,-CH,Ph or -C(Me),Ph and R’ = Me or But the rates and activation parameters both for inversion and R’ exchange were determined. The values obtained were shown to be almost indepen- dent of both complex concentration and the solvent. They were also similar for the two processes indicating a common intramolecular mechanism. The ratio between ’ F. A. Cotton J. Chem. Educ. 1983 60 713. J. D. Corbett and H. S. Marek Inorg. Chem. 1983 22 3194. L. M. Seaverson and J. D. Corbett Znorg.Chem. 1983 22 3202. P. J. McCarthy and M. F. Richardson Inorg. Chem. 1983 22 2979. ’ R.C. Fay and A. F. Lindmark J. Am. Chem. Soc. 1983 105,2118. 171 J. E. Newbery R' H 0'qRt RO..,.. I .,o .Ti>''. RO' R' H (1) the two rate constants (ki,,/kexch) falls from -2.0 to -1.0 as the steric bulk of the alkyl groups increases. In [RB(pz),]Zr(OBu')Cl, where pz = pyrazoyl the zirconium atom is in an octahedral site being co-ordinated by a nitrogen from each of the pyrazoyl rings. For R = H pz Pri or Bun the complexes are fluxional6 at room temperature but for R = H and with the 3,5-dimethylpyrazoylborate,a 2 1 pattern is shown in both 'H and 13C n.m.r. spectra as a result of the differing environments. Kinetic processes in Group IV octaco-ordinate complexes have also' been investi- gated by n.m.r.The N,N-dimethylmonothiocarbamate (Me,NCSO-= L) complexes ML4 M = Ti or Zr have AG* of cu. 75 kJmol-' for C-N rotation and cu. 45 kJ mol-' for metal-centred rearrangement. The corresponding dithiocarbamates (R,NCS,) are still non-rigid on the n.m.r. time-scale at -140 "C. The range of ligand types found with Group IV metals is quite large. In Zr(BH,Me), the metal has been shown' by X-ray diffraction to have the expected tetrahedral co-ordination from the boron atoms (Zr-B = 2.56 A) but also to be in close proximity to the BH protons. Phosphine ligands however are generally regarded as being more difficult to co-ordinate. The ligand N(SiMe,CH,PMe,), (L) has the advantage of having a 'hard' amido centre to act as an anchor-point and yet might still involve 'soft' phosphorus.Reaction of Li.L with either ZrC14 or HfC14 gives MC12L2 and a single-crystal X-ray diffraction study' has shown distor- ted-octahedral geometry with one phosphorus atom free and the other co-ordinated. The porphyrin complex Ti(OMe)tpp where tpp is tetraphenylporphyrin is noteworthy" for having the methoxy group almost coilinear with the metal (Ti-0-Me = 171") and a rather short Ti-0 bond (1.77 A). Some of the more interesting organometallic species reported for this group involve various metallacycles. A useful new route to the metallacyclobutanes has been described" (Scheme 1). The method also should be effective with other metals. The synthesis of oxa-metallacycles has been shown' to result from using an alkoxide to promote ring closure (Scheme 2).The structure has been confirmed by X-ray analysis and has the two bent metallocenes linked by two oxygen bridges. D. L. Reger and M. E. Tarquini Inorg. Chem. 1983 22 1064. ' S. L. Hawthorne A. H. Bruder and R. C. Fay Inorg. Chem. 1983 22 3368. R. Shinomoto E. Gamp N. M. Edelstein D. H. Templeton and A. Zalkin Inorg. Chem. 1983,22,2351. M. D. Fryzuk H. D. Williams and S. J. Rettig Inorg. Chem. 1983 22 863. C. J. Boreham G. Buisson E. Duke J. Jordanov J.-M. Latour and J.-C. Marchon Inorg. Chirn. Actn 1983 70 77. 'I J. W. F. L. Seetz G. Schat 0. S. Akkerman and F. Bickelhaupt Angew. Chem. lnt. Ed. Engl. 1983 22 248. I* H. Takaya M. Yamakawa and K.Mashima 1. Chem. SOC.,Chem. Commun. 1983 1283. '0 Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn,Tc Re Me Me CpMCI, Mg ~ Mze21 MfiMe Et,O Br Br BrMg MgBr -Et,O ' M cp' 'cp M = Ti Zr or Hf Scheme 1 R n\ R = H or Me \ K Scheme 2 Et Et-CZC-Et - Cp2Mp-(I CP 2M Et M = Ti or Zr Scheme 3 Various metallacyclopentadienes are shown13 (Scheme 3) to undergo ring expansion with alkynes into metallacycloheptatrienes. The products were identified by their mass spectra and from the nature of the hydrocarbons formed on treatment with HC1-CHCl,. The lability of the carbonyl groups in Cp,Ti(CO) is well-estab- lished,I4 and they have now" been shown to be capable of replacement by S4N4 giving Cp2Ti(N4S3). The titanium atom is bonded to two nitroogens to form a metallathiazene ring.The (NS)atoms are almost planar (k0.12 A) with the metal 0.58 A above the ring. Some five-co-ordinate metallocene complexes have been characterized. (Cp),Zr(CF,SO,),.thf has been shown16 to have Zr-0-S at 155.2' and the angle betweep the two rings at 127.8". The Zr-0 distance to the thf is significantly longer (2.278 A) than that to the OS02-CF3 group (2.219 A). In (Cp),ZrCl(S,CNEt,) the Cp rings make a similar angle of 128.9' at the metal centre." The Zr C1 and two S atoms of the bidentate ligand lie in a quasi mirror-planeFlmost peTendicular to the plane of the Zr and the centroids of the Cp rings. At 2.56 A and 2.72 A respectively the Zr-C1 and Zr-S distances are exceptionally long. A Cp-Zr-Cp angle of 128.8" also is found'* in one of the products of the reaction of diazoalkanes R,C=N=N (R = Ph or CO,Et) on Cp,ZrRi (R' = Me or CH2Ph) or (Cp,ZrHCl),.An insertion process into the Zr-C or Zr-H bond l3 A. Famili M. F. Farona and S. Thanedar J Chem. SOC.,Chem. Commun. 1983 435. l4 B. H. Edwards R. D. Rogers D. J. Sikora J. L. Atwood and M. D. Rausch J. Am. Chern. SOC.,1983 105 416. C. G. Marcellus R. T.Oakley A. W. Cordes and W.T. Pennington J. Chem. Soc. Chem. Commun. 1983 1451. l6 U. Thewalt and W. Lasser 2.Naturforsch. Ted B,1983 38 1501. " M. E. Silver 0. Eisenstein and R. C. Fay Inorg. Chem. 1983 22 759. l8 S. Gambarotta C. Floriani A. Chiesa-Villa and C. Guastini Inorg. Chem. 1983 22 2029. J. E. Newbery occurs with the formation of a q2-N,N hydrazonato ligan! (2).The nitrogen carrying the R' group is the closer of the two (Zr-N = 2.lOA and 2.28A). q2-N,N is in~olved'~ also in the reaction product of azo compounds R-N=N-R (R = Ph or p-MeC,H,) with Cp2Ti(C0),. The metal atom is shown to take up pseudo- tetrahedral co-ordination with the angle Cp-Ti-Cp being 133.0". The N-N bond distance is 1.34 A and the nitrogen atoms are at 1.965 and 1.971 A from the metal. Results from a quantitative ab initio molecular orbital treatment of TiCl,(MeN=NMe) as a model are consistent with the conformation adopted. Me \ Ph\ N cp ,C," \ I Zr -Me Ph I CP (2) The formation of a number of zirconium(rI1) hydrides and alkyls is reported. Reduction of ZrCp2C12 by Mg-thf gave" a reddish-brown coloration with the presence of a Zr"' paramagnetic species being revealed by the intense e.s.r.spectrum obtained. Initially a singlet flanked by 9'Zr satellites was observed but over a period of 48 hours this turned into a doublet. Detailed analysis of the spectra and of others from reductions in the presence of substrates such as styrene indicates the formation of a mononuclear zirconium(Ir1) hydride. The hydrogen appears to have been abstracted from a Cp ring. Hydrides are also postulated2' as products from the photolysis of ZrCp,RX and ZrCp,X,. When carried out in the presence of phos- phines a different e.s.r. signal was obtained suggesting the formation of tertiary phosphine adducts of Zr"'. The compound Ti(q-C7H7)(q-C7H9) is normally produced by the reaction of T~(T-C~H~M~)~ with cycloheptatriene in the presence of (A1Et2Cl), resulting in near quantitative conversion.If however the titanium starting material is treated with (AlEtCl,) and cycloheptatriene in tetrahydrofuran red crystals of a binuclear complex are obtained.22 The structure [Ti( q-C7H7)(C,H,0)(fi-Cl)]2 was elucidated by X-ray diffraction methods. The dichloro bridge can be cleaved by tertiary phosphines or amines and species of the type Ti( q-C,H,)(t-ph~s)~Cl formed. Further treatment with Grignard reagents allowed compounds such as (3) to be synthesized. The X-ray-determined structure gives no indication of interaction between the metal and ethyl group hydrogen atoms. (3) l9 G. Fochi C. Floriani J. C.J. Bart and G. Giunchi 1. Chem. Soc. Dalton Trans. 1983 1515. 20 E. Samuel Inorg. Chem. 1983 22 2967. *' A. Hudson M. F. Lappert and R. Pichon J. Chem. Soc. Chem. Commun. 1983 374. 22 M. L. H. Green N. J. Hazel P. D. Grebenik V. S. B. Mtetwa and K. Rout J. Chem. SOC.,Chem. Commun. 1983 356. Ti,Zr Hf;V Nb Ta; Cr Mo W; Mn,Tc Re Finally in this section on Group IV transition metals there are some reports on heterobimetallic complexes. Thus M(CO),(Cp) (M = Ti or Zr) will react23 with W( rCC6H4Me-p)(CO),(Cp) in toluene to give MW(p-CC6H4Me-p)(p-CO)(CO) (CP)~. The structure of the titanium fpecies was determined by X-ray diffraction (4). The Ti-W bond length is 2.977 A. The bridge system is nearly linear and the W-carbonyl group q2to the titanium makes a decidedly non-linear angle (OCW = 165").One interesting point is that although their environments are quite distinct C H Me l6 c? .F+ /"" TI-W c; 1 c' 'CP (.j4 (4) only one resonance was observed for the 13C0 n.m.r. at room temperature for the Zr complex. Two peaks differing by only 0.6 p.p.m. were seen on cooling to -80 "C. Similar behaviour was also observed24 for the complex Cp2RZr- RU(CO)~C~ with R = Me. With R = OCMe3 the Zr-Ru distance in these unbridged entities was shown to be 2.91 A. 3 Vanadium Niobium and Tantalum LiV2F6 has been shown25 to be a true mixed-valance compound. It exhibits a trirutile lattice with two edge-sharing distorted VF6 octahedra and a single V site. The complex compounds will be classified in the order mononuclear bridged and metal-metal bonded moieties.The polymeric entity {V(NO),Cl2}, can26 be reduced by Na/Hg in acetonitrile. In the presence of ligands complexes such as V(N0)2L2Cl(L = MeCN or methyl isonicotinate) or [V(NO),(BU'NC)~]PF~ can be isolated. The compounds were characterized by infrared analysis and from "V n.m.r. The oxovanadium ion V02+ exhibits a strong preference for oxygen donors when offered2' the compartmental ligand derived from (5). Whereas both copper(I1) and (5) 23 G. M. Dawkins M. Green K. A. Mead J.-Y. Salaun F. G. A. Stone and P. Woodward J. Chem. Soc. Dalton Trans. 1983 527. 24 C. P. Casey R.F. Jordan and A. L. Rheingold J. Am. Chem. SOC.,1983 105 665. 2s R. M. Metzger N. E. Heimer C. S. Kuo,R.F. Williamson and W.0. J. Boo Inorg. Chem. 1983 22 1060. 26 M. Herberhold and H. Trampisch Inorg. Chim. Acta 1983 70 143. 27 J.-P.Costes and D. E. Fenton J. Chem. SOC.,Dalton Trans. 1983 2235. J. E. Newbery nickel(I1) give a mixture of two complexes showing either all oxygen or oxy-gen/nitrogen donation to the metal V02+ gives only the former. Heterocyclic amines (L) have been known to co-ordinate to vanadium(I1). A more convenient route to such species as VL4X2 or [VL6]X2 X = C1 or Br is28 uia the ethanolate. Mixture of the hydrated vanadium dihalide with ethanol and triethyl- orthoformate gives VBr2.6EtOH or VCl,.n EtOH (n = 4 or 2). These are exceptionally useful as sources of V"' in cases where water may oxidize the potential ligating molecule.In a similar vein the structures of VC13.3thf and VC12.2thf are reported.29 While the former is monomeric mer-VCl,(thf), based on octahedral co-ordination (angles are cis Cl-V-Cl of 92.0" and cis 0-V-0 of 86.2"),the latter complex is shown to be not even a pure vanadium compound since it is actually [V2(p- Cl),(thf)&[Zn,(p -C1)2C14]2-. Apart from the vanadium (and of course zinc) the analytical percentages are similar for the two formulations. The structure of the cation is based on face-sharing of two regular octahedra. A 1 1 reaction product is readily formed from NbSC13 and Ph3PS. This has now been established3' by X-ray crystallographic work to consist of two separate species. Each unit-cell contains two monomer units and one dimer.The monomers are five-co-ordinate square pyramidal with the lone sulphur atom occupying the axial position. The metal is displaced towards this atom (above the square plane) by 0.55 A. The dimeric unit contains edge-sharing distorted octahedra (6). ,s /\ I CI PPh (6) The vapour-phase decomposition of a number of fluorinated V'"0 /3 -diketones shows3' the formation of VOF2 and a furanone (e.g. C5HF,02 C5H4FZ02 etc.). A correlation has been noted32 between both the frequency and the extinction coefficient and the solvent strength (defined in donor/acceptor terms) for the elec- tronic absorption spectrum of VO(acetylacetonate) in fifteen different organic solvents. The synthesis of a number of novel vanadium(v) alkoxides is reported.33 VO(0R) (dipic).H,O (where dipic is 2,6-pyridinedicarboxylate)and VO(OOR)(dipic).H20 were prepared from aqueous solution by standard procedures.The structure of the latter species with R = But is notable for the presence of an 0-0-bonded 2n L. F. Larkworthy and M. W. O'Donoghue Inorg. Chim. Acra 1983 71. 81. 29 F. A. Cotton S. A. Duraj M. W. Extine G. E. Lewis W. J. Roth C. D. Schrnulbach and W. Schwotzer J. Chem. SOC.,Chem. Commun. 1983 1377. 30 M. G. B. Drew and R. J. Hobson Inorg. Chim. Acm 1983 72 233. 3' D. A. Johnson and A. B. Waugh Polyhedron 1983 2 1323. 32 A. Urbanczyk and M. K. Kalinowski Monatsh. Chem. 1983 114 13 I I. 33 H. Mimoun P. Chaumette M. Mignard L. Saussine J. Fischer and R. Weiss J. Nouu. Chim. 1983 7 467. Ti,Zr Hf;V Nb Ta;Cr Mo W;Mn Tc Re alkylperoxo group (7).oThe terminal oxygen being closer to the metal (1.87 A) than the latter group (2.00A).The angle 0-V-0 is 43.4'. Such structures may prove to be common amongst dn metal alkylperoxo intermediates involved in the catalytic epoxidation of olefins. Q (7) In the general trend towards the elucidation of the biological role of vanadium several reports of complex formation involving ligands of potential biological significance have appeared. Purine or adenine (L) can co-ordinate to vanadium(1v) to produce3 VO(LH)C12. Vanadium(II1) forms green water-soluble complexes with the amino acids methionine glutamic acid and aspartic acid.35 Both simple (e.g. V glu V asp, or V met,) and mixed ligand (e.g. V asp.met V asp.glu or V glu.met) examples were characterized by thermal analysis and infrared spectroscopy.With cysteine vanadium(r1) rapidly forms36 a complex V" cys. Over a period of a few minutes this decomposes to the corresponding V"' species with the evolution of dihydrogen. Hydrogen release is suppressed by the addition of either V'" or cystine but V"' cys is still formed. Thiolate bonding analogous to that involved in cysteine linkages is found in the complexes formed from the ethane- 1,2-dithiolate ion (edt). VO(acac) will give3' the ion [V0(edt),l2- while VC13 produ~ed~'*~* [V,(edt),12-. The former ion is found to be square pyramidal with the oxygen taking the apical position. The V-0 distance is 1.62 A and thus a little long for such (V=02') moieties and perhaps explains the lowish V-0 stretching frequency at 928 cm-'.Analysis of the e.s.r. spectrum indicates that there is enhanced electron density at the metal as compared to that found for VO(acac),. In the ion [V2(edt),I2- the structure found corresponds to [(edt)V(p-edt),V(edt)I2-where each vanadium is in a sevtrely distorted octahedral environment. There is also a possible V-V bond (2.60 A). An interesting effect is in the complexes TaCl,(diph~s)~ and [TaCl,(diphos),]+ where diphos = Me,PCH,CH2PMe2. The neutral molecule adopts a square anti-prismatic structure with Ta-Cl = 2.50 A and Ta-P = 2;65 A whilst the comelex ion is dodecahedra1 with the Ta-Cl bond length of 2.43 A and Ta-P of 2.69 A. It is well-established that these structures are of similar stability and it thus becomes difficult to ascribe a reason for the switch.Dodecahedra1 co-ordination is also ~uggested~"~' in the preliminary reports of the X-ray structures on the hydride complexes TaCl,H,(diphos) and TaCl2H,(PMe3),. 34 C. M. Mikulski S. Cocco N. de Franco and N. M. Karayannis Inorg. Chim. Acta 1983 78 L25. 35 1. Grecu R. Sandelescu and M. Nearntu Andes de Quimicu 1983 79 18. 36 G. Kalatzis J. Konstantatos E. Vrachnou-Astra and D. Katakis J. Am. Chem. SOC.,1983 105 2897. 37 R. W. Wiggins J. C. Huffman and G. Christou J. Chem. SOC.,Chem. Commun. 1983 1313. 38 (a) J. R. Dorfrnan and R. H. Holm Inorg. Chem. 1983 22 3179; (b) D. Szeymies B. Krebs and G. Henkel Angew. Chem. Int. Ed. Engl. 1983 22 885. 39 F. A. Cotton L.R. Falvello and R. C. Najjar Inorg. Chem. 1983 22 770. 40 M. L. Luetkens jun. J. C. Huffman and A. P. Sattelberger 1. Am. Chem. Soc. 1983 105 4474. 4' M. L. Luetkens jun. W. L. Elcesser J. C. Huffman and A. P. Sattelberger J. Chem. Soc. Chem. Commun.. 1983. 1072. 178 J. E. Newbery Turning to macrocyclic ligands the niobium(rv) porphyrins NbX,(por) where (por) = tetraphenyl- tetra-rn-tolyl- or tetra-p-tolyl-porphinato can be conveniently synthesi~ed~~ from the corresponding NbvX,(por) species (X = CI or Br) by reduc- tion with zinc amalgam. Irreversible oxygenation readily occurs and causes the appearance of a new e.s.r. line the structure of which is in accord with the formation of a superoxo NbV complex NbX,O,(por). Analysis of EXAFS data supports axial symmetry for a series of compounds VIVS(por) formed from V"(por)(thf) by direct action of sulphur.43 An unusual dinuclear vanadate complex is formed by the reaction between VC1,.3thf and 2-hydroxy-6-methylpyridine (HL) to give44 V202C1,(p-HL),.This has apparently neutral molecules in a bridging role but actually employs the zwitterion form 2-0x0-6-methylpyridinium. The N-H protons were located in the X-ray crystallographic analysis. Two of the bridging ligands are asymmetrical and one is symmetrical. The metals are in a very distorted octahedral environment with the V-V distance quite large at 3.175 A. E.s.r. evidence was used to show the presence of oxovanadate(1v) rather than (v). The addition of diphenylethyne to a mixture of NbCls and NbOCl in dichloromethane dark green crystals of formulation (C,ClPh,)+( Nb20C19)-.X-Ray crystallographic analysis shows the presence of this interesting oxygen-bridged dinuclear dimer (Nb-0-Nb = 174.1") but surprisingly enough the dimer is also associated via unsymmetric chloro bridges into a centrosym- metric tetramer (8). This bridge has equal Nb-Cl separation within each arm but a considerable difference between the arms (249 pm and 270 pm). NBut c1/ 6'.1 Cl\\ /Cl c1,Nb\ c1I c1 I NBut The reaction between V(NPh)Cl and Bu'(Me,Si)NH produces a product that has been identified46 by X-ray analysis as having the structure (9) V,Cl,(NBu'),(p,- NPh),(p,-PhNCONHBu'). This has a (VN) ring with the metal bridged by pheny- limido groups at fairly uniform distances (V-N = 1.85 to 1.9 I A).Each vanadium is at the centre of a distorted trigonal bipyramid. The most interesting part of the structure is the formation of the PhNCONHBu' ligand which then adopts a triple- bridging mode via the oxygen atom. 42 P. Richard and R. Guilard J. Chern. SOC.,Chern. Cornmun. 1983 1454. 43 J.-L. Poncet R. Guilard P. Friant and J. Goulon Polyhedron 1983 2 417. 44 F. A. Cotton G. E. Lewis and G. N. Mott Znorg. Chern. 1983 22 378. 4s E. Hey F. Weller and K. Dehnicke Z. Anorg. Allg. Chern. 1983 502 45. 46 D. C. Bradley M. B. Hursthouse A. N. de M. Jelfs and R. L. Short Polyhedron 1983 2 849. 179 Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn Tc Re S4N4 reacts4' with VC14 in dichloromethane to give a mixture of VC12(S2N3) and S2N2VC14.The latter compound proved to be difficult to obtain in a completely pure form but the former crystallizes into black needles. It was shown to consist of chloro-bridged dimers further linked into a polymeric chain (10). (10) Metal-metal bonds are present in quite a few Ta"' dinuclear complexes. Ta,C16(Me2PC2H4PMe2)2 is formed4' from Ta,Cl,(Me,S) as red crystals by the direct action of the diphosphine in dichloromethane solution. It has two bridging chlorines in an edge-sharing mode between two octahedrons with the phosphorus atoms all in equatorial positions. This is a distinct difference from the related Ta2Cl6(PMe3) complex where one paireof phosphines are equatorial and the other are axial. The Ta-Ta distance is 2.71 A consistent with a double bond.A minor by-product of the reaction (1 l) has a further arrangement of the diph~sphines.~~ Ta,Cl,(diphos),(p -O)(p-SMe,) is evidently formed by traces of water in the reaction mixture and may have a (p-OH) group instead of the 0x0 group protons being rather d$€icult to locate. This is also a Ta=Ta complex with an inter-metal distance of 2.73 A. ON (1 1) (12) Vanadium shows a single V-V bond (2.61 A) in the compound (Pr'Cp),V2S4 prepared5' from (Pr'Cp)VC12. The metals are bridged by one 7'-S2 ligand and by two S ligands. The former ligand is converted into the v2-S2bridging mode by reaction with hexafluoro-but-2-yne to give the black lustrous (Pr'Cp)V2S4.C2(CF3)2 where the butyne has added across the single sulphides to form a p-v2-S2C2(CF3) ligand.A related vanadium compound (MeCp),V2S4 reacts5' with Hg[Fe( NO) (CO)3]2 in toluene to give a molecule with a cubane structure (MeCp),V,Fe,( NO)& (12). The species is electron-deficient (58e) Fnd shows some signs of intermetallic contact (Fe-Fe = 2.59 A Fe-V = 2.75 A and V-V = 2.95 A). A linear heterometallic complex ion [VFe2S4Cl4I3- can5* be precipitated from an acetonitrile solution containing [FeCl,]- and [VS,]'-by the addition of ether. 47 H. W. Roesky J. Anhaus H. G. Schmidt G. M. Sheldrick and M. Noltemeyer J. Chem. SOC.,Dalron Trans. 1983 1207. 48 F. A. Cotton L. R. Falvello and R. C. Najjar Inorg. Chem. 1983 22 375. 49 F. A. Cotton and W. J. Roth Inorg. Chem. 1983 22 868. 50 C. M.Bolinger T. B. Rauchfuss and A. L. Rheingold J. Am. Chem. Soc. 1983 105 6321. 5' T.B. Rauchfuss T. D. Weatherill S. R. Wilson and J. P. Zebrowski J. Am. Chem. Soc. 1983 105,6508. 52 Y.Do E. D. Simhon and R. H. Holm 1.Am. Chem. SOC.,1983 105 6731. J. E. Newbeiy The absorption spectrum of this ion in acetonitrile is recognizable as that of a perturbed [VS,]'- chromophore. The solid-state structure has ifealized D2d sym-metry about the vanadium (13) and the V-Fe distance of 2.73 A is similar to that in the cubane (12). (13) (14) The structure of 'VCl,(thf),' has been shown29 to be [v,(p-C1)3(thf)6]2[zn&16]. If a thf slurry of this species is mixed with PMe2Ph followed by LiBH an actual heterometallic complex is formed. V,Zn2H,(BH,)2(PMe2Ph)4 has been shown53 to be symmetrical about a central V-V structure (14).Organometallic Compounds.-V(CO) is the only homoleptic metal carbonyl that is a stable free radical. In the solid state it appears black as a result of a weak electronic transition centred at 580 nm. In dilute solution or at 15 K in a nitrogen matrix it shows no absorption below ca. 840nm. Based on SCF-Xa-DV calculations it is suggested5 that the solid-state transitions show some analogy to donor-acceptor charge-transfer bonds with the process v(co),v(co) -?+~V~C~),'.l[V(CO),l becoming important. The "V n.m.r. spectra of a series of complexes [V(CO),L]- have been measured.55 The chemical shifts from the various ions were arranged in a series that reflects decreasing T-and increasing cT-interaction as the electronegativity of L increases CO > CNR = SbR > PR > AsR > BiR > DMSO (S-co-ordinated) > NCR > py > (oxygen donors) The chemical shifts relative to VOC13 ranged from -1951 p.p.m.for L = CO to -534 p.p.m. for L = 02NPh. The thermally unstable and highly reactive molecule V(CO)5N0 has been known for a number of years but there is little information on its reactions. It can be readily obtained in high yield by mixing [Et,N][V(CO),] and [NO][BF4] in dichloromethane. A large number of reactions was investigated (Scheme 4).56 Two facile syntheses are reported for M(C0); (M = Na or Tb). Starting from MCl, the complex M(C,,H,)2- was first formed5' by addition of sodium naph- thalenide in DME. This complex ion takes up carbon monoxide quite readily at -60 "C and atmospheric pressure to yield M(C0);.Alternatively the chloride can be turned into M(C0); by reductive carbonylation with Mg-Zn-py-CO. 53 R. L. Bansemer J. C. Huffman and K. G. Caulton J. Am. Chem. SOC.,1983 105 6163. 54 G. F. Holland M. C. Manning D. E. Ellis and W. C. Trogler J. Am. Chem. Soc. 1983 105 2308. 55 D. Rehder and K. Ihmels Znorg. Chim. Acfa 1983 76 L313. 56 K. L. Fjare and J. E. Ellis J. Am. Cbem. Soc. 1983 105 2303. 57 C. G. Dewey J. E. Ellis K. L. Fjare K. M. F'fahl and G. F. P. Warnock Organornernllics 1983 2 388. 58 F. Calderazzo U. Englert G. Pampaloni G. Pelizzi and R. Zamboni Inorg. Cbem. 1983 22 1865. Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn Tc,Re V(CO),( NO)(diphos) (i) Na(DME)Cp [CO) MnV( CO),NO]- [V(CO),NO],( diphos) [v(co>4(No)II-trans-V(CO),(NO)(NMe,) tmns-V(CO),( NO)( PR,) Scheme 4 For niobium the process works at room temperature and atmospheric pressure with ca.48% yield. The ion is capable of further reduction59 by sodium in liquid ammonia to give Na,[M(CO),J. The caesium version of this salt has the unsociable habit of being shock-sensitive and thus liable to explode. Spin-lattice relaxation methods were employed6' to show that the barrier to the rotation of the cyclopentadienyl ring in CpV(CO) is 7.1 kJ mol-*. An interesting series of nobium complexes where the metal progresses from do to d2 has been prepared.61 [NbR,(Cp),]+ [NbR2(Cp),J and [N~R,(CP)~]- where R = (o-CH&H,)~ were produced in forms suitable for single-crystal X-ray analysis.In very broad terms the niobium is tetrahedrally bonded but there are progressive changes for example the torsion angle of the biphenyl changes from 59.6" to 62.4" and finally to 78.4". The angle CH2-Nb-CH2 alters from 80.0"to 83.0" and 106.3". The full structural characterization of a T8-C8H8 vanadium complex is reported.62 (q8-C8H8)V[Et2C2B4H4]was synthesized by the reaction of K2C8H8 with [2,3- (Et)2C2B4H5]- and VC13 in tetrahydrofuran. It was isolated as a dark green air-stable solid after t.1.c. separation using hexane as eluant. X-Ray crystallographic analysis shows a sandwich environment for the metal (15). The vanadium atom is 1.375 A from the C8 plane and 1.830 A from the C2B3 ring of the carborane.4 Chromium Molybdenum and Tungsten A number of reviews concerning Group VIB metals have been published. These are mostly concerned with the biological role of the elements. Thus chromium can be 59 G. F. P. Warnock J. Sprague K. L. Fjare and J. E. Ellis J. Am. Chem. SOC.,1983 105 672. 60 D. F. R. Gilson G. Gomez I. S. Butler and P. J. Fitzpatrick Can. J. Chem. 1983 61,737. 6' L. M. Engelhardt W.-P. Leung C. L. Raston,and A. H. White J. Chem. SOC.,Chem. Commun. 1983,386. 62 R. G. Swisher E. Sinn G. A. Brewer and R. N. Grimes J. Am. Chem. Soc. 1983 105 2079. 182 J. E. Newbery classed63 as an ultra-trace element essential to animal life. In the natural state it is found as Cr"' but 'man-made' CrIVis carcinogenic.Model compounds that attempt to mimic aspects of the Mo-hydroxylases are reviewed64 in an account with 67 references. For convenience the rest of this section will be subdivided into 'simple' compounds co-ordination compounds and organometallics. Simple Compounds.-This designation covers both binary compounds and some complex ions particularly the heteropolyanions. The structure of NaMO,O is chain-like based on trans edge-sharing octahedra. A one-dimensional model has been developed65 to discuss the metal-metal interac- tions in such extended systems. Although having seemingly obvious limitations the model proved useful in many aspects of the chemistry of this class of compounds particularly in suggesting that structural distortions result from increasing the elec- tron count on the molybdenum chains.Possible structures (16) for a number of molybdenum ions in aqueous solution are suggested from Fourier transform analysis of EXAFS data.66 Lf I+ MoV Mo'" .-2.54H-+ L+ Mo'" The preparation and unit-cell parameters of a number of complex salts A,[MOX,] where A = K Rb or Cs; M = Cr Mo or W; and X = C1 or Br are With potassium only K,MoOCI could be isolated and this may result from excessive solubility of the other salts. Gaseous chromyl fluoride Cr02F2 has been investigated by electron diffraction procedures.68 A quadratic force-field waszvaluated and force constants determined by normal co-ordiKate analysis. The F-Cr-F angle was found to be 111.9" larger than that of 0-Cr-0 (107.8') but not an excessive deviation from tetrahedral symmetry.The mixed-valence ion [W408C18(H20)4]2- can be produced by an equilibrium between Wv'02CI~- and W"0CI;- in concentrated hydrochloric acid. It does not show high stability but the corresponding thiocyanate [W408(NCS)12]6- gave a 63 W. Mertz Chem. Scr. 1983 21 145. 64 J. T. Spence Coord. Chem. Rev. 1983 48 59. 65 T. Hughbanks and R. Hoffmann J. Am. Chem. SOC.,1983 105 3528. 66 S. P. Cramer P. K. Eidem M. T. Paffett J. R. Winkler Z. Don and H. B. Gray J. Am. Chem. Soc. 1983 105 799. 67 J. E. Fergusson A. M. Greenaway and B. R. Penfold Inorg. Chim. Acta 1983 71 29. R. J. French L. Hedberg K. Hedberg G. L. Card and B. M. Johnson Inorg. Chem. 1983 22 892. Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn,Tc Re caesium salt that was studied69 by X-ray crystallographic methods (17).The tungsten atoms form a regular plane and are each roughly octahedral. The disposition of the terminal oxygens differs from that found previously for the chloro ion where an alternating geometry was observed. s C S (17) Moving on to the heteropolyanions evidence is presented7' for the formation of 1 1 complexes between a number of tungsten species and polylysines. Precipitation can be induced and a reactivity order NaAs,W,,O:~ > NaSb9W2,0~~-> SiW,,O& was established. This has some similarities to in vivo and in vitro antiviral activity of these polyanions which are believed to inhibit DNA and RNA poly- merases. Polypeptide precipitation is recommended as a simpler test to apply and a correlation with electrostatic charge per accessible surface area is suggested as an explanation of the reactivity differences.Many of the interesting papers in this area now involve the application of Ig3W n.m.r. studies. For example the PWIIOi; ion can form 2 1 complexes with f-transition metals. Thus with cerium paramagnetic [Ce"'(PW 1039)2]11-and diamag- netic [Ce'"(PW 1039)2]10-can be formed.71 A sharp six-line spectrum is observed for the paramagnetic ion and a much more complex pattern for the diamagnetic. It is suggested that whereas the 'ligands' in the former ion are twisted by either 0" or 180" in the latter there is a 90" twist. A six-line spectrum was also found7* for TiPW (intensity order 2 :2 :1 :2 :2 :2).A detailed analysis of the spectrum and peak assignment was made by constructing a chemical-shift/spin-couplingmatrix. TiPW,,O:; shows five peaks of equal inten~ity.'~ For maximum utility of Ig3W n.m.r. results in these complex systems it is essential to have unambiguous peak assignment. This can be achieved7 through the use of a similar procedure to that employed for I3C,namely two-dimensional n.m.r. Several examples are quoted and contradictions with some recent assignments are evident. Some data have been obtained on ligand exchange in lacunary heteropolytung- The process studied was the expulsion of water from such anions as 69 J. P. Launay Y. Jeannin and A. Nel Inorg. Chem. 1983 22 277. 70 M. Hervi G. Hervt F. Sinoussi J.-C.Chermann and C. Jasmin Now. 1. Chim. 1983 7 515. " L. P.Kazansky and M. A. Fedotov J. Chem. Soc. Chem. Commun. 1983 417. 72 W. H. Knoth P. J. Domaille and D. C. Roe Inorg. Chem. 1983 22 198. 73 P. J. Domaille and W. H. Knoth Inorg. Chem. 1983 22 818. C. Brevard R. Schimpf G. Tourni,and C. M. Tourni. J. Am. Chem. Soc. 1983 105 7059. 74 75 F. Zonnevijlle C. M. Tourni and G. F. Tourni Inorg. Chem. 1983 22 1198. 184 J. E. Newbery [MFe(H20)W,,039]n- (where n = 4 M = P or As; n = 5 M = Si or Ge; or n = 6 M = B) and [M2Fe(H20)W,706,]7- (for M = P or As). Values of the standard equilibrium constant were obtained from spectroscopic measurements using Job’s method (continuous isomolar variation) or molar ratio variation. For Fe(CN)z- as the exchanging ligand the values found were over ten times larger than those for S20<- but much alteration was evident along the series of polyanions and also from changes in solution pH.A study has been made of the reduction characteristic^'^ at a glassy carbon electrode of a number of heteropolyanions of general formula (P2W,8-n MO,O,~)~-. The ions divide into two classes depending on whether the observed 2e-change occurs in one step or two steps. This division was correlated with changes in the M-0-M angle between the two ZM ‘half-anions’. Co-ordination Compounds.-The classification followed in this section starts with mononuclear compounds and moves via bridged complexes through to metal-metal bonded entities. Within each sub-group the articles are arranged by donor type and in order of increasing ligand denticity.The formation and reaction of dinitrogen complexes continues to produce some exciting results. One preliminary note7’ records the possible formation of a bis carbon dioxide complex for molybdenum by the loss of dinitrogen from Mo(N2) (Ph2PCH2CH2PPh2). This was achieved by direct action as a yellow air-stable compound in 75% yield. The complex tran~-Mo(N~)~(triphos)(PPh,) is known to decompose with evolution of ammonia on treatment with HBr-thf. On a closer e~amination’~ the initial formation of hydrazine can be detected. This was attained by allowing the decomposi- tion to run for a set time then removing volatiles and adding water-CH2C12 to the solution. Analysis of the aqueous phase was then made to detect the amounts of hydrazine and ammonia present.The hydrazine yield goes through a maximum of ca. 0.16 mol N2H4 per mol Mo after about one hour and then progressively decreases. The ammonia yield continually rises being ca. 0.15 mol per mol Mo after 1 hour and 0.72 mol per mol Mo after 60 hours. The production of hydrazine in this fashion is similar to the behaviour found in nitrogenase. Mixtures of trans-Mo(N,),(PMePh,) and pyridine (or 4-Me py) eq~ilibrate’~ with rrunqrner-Mo(N2),(py)(PMePh2) and the equilibrium constants have been found by 31P n.m.r. to be four and seven (for py and 4-Me py respectively). If a five-fold excess of the tetra-phosphine complex is added this trans,mer complex can be precipitated but as a mixture.Benzene solutions of the complex are purple and decompose in vacuo depositing red-brown precipitates. These have been shown by n.m.r. spectroscopic methods to be formulated as .rr-complexes Mo(~,~,-py) (PMePh,),. In this area of study much attention has been directed at trans-M~(N~)~(phos)~ species and thus the synthesis characterization and an account of some of the properties of a cis variant is very welcome.8o cis-[Mo(N,),(PMe,),] was prepared 76 J. P. Ciabrini R. Contant and J. M. Fruchart Polyhedron 1983 2 1229. 77 J. Chatt W. Hussain and G. J. Leigh Transition Met. Chem. 1983 8 383. 78 T. A. George and L. M. Koczon J. Am. Chem. Soc. 1983 105 6334. 79 R. H. Morris and J. M. Ressner J. Chem. SOC.,Chem. Commun.1983 909. 80 E. Carmona J. M. Martin M. L. Poveda J. L. Atwood and R. D. Rogers J. Am. Chem. SOC.,1983 105 3014. Ti,Zr Hf;V Nb Ta; Cr Mo W; Mn Tc Re according to (Scheme 5) by reduction of a Mo"' complex. Also noteworthy is the reaction product with further PMe3 where one of the dinitrogens has been expelled to give Mo(N~)(PM~~)~. Crystallographic structural data are reported" for two molybdenum-nitrogen complexes. MoN(N,)(diphos) is octahedral about the metal with equatorial phos- phines. The azide group is of special interest in being linear (N-N-N = 179"). The Mo-N (nitrido) is rather long at 1.79 A and this may result from the trans azido-group. A similar overall geom:try was found also in [MoBr(NH)(diphos),]+ where the Mo-Br distance is 2.61 A and Mo-NH is 1.73 A.Preparative procedures for the synthesiss2 of a range of organoimido-tungsten compounds are shown (Scheme 6). These complexes are notable for having tungsten tin oxidation states IV v and VI.X-Ray structural data were obtained on a number of these compounds. Perhaps the most interesting of these is the W'" species W(NPh)Cl,(PMe,),. This has rner-phosphines and each of the phosphines is cis to the -NPh group. WOCl [W(NR)C13L; rW(NR)CI L31 L' = PMe,Ph PPh (L = PMe, PMe,Ph or CNBu') L; = Ph2PCH,CH,PPh2 Reagents i RNCO; ii MgMe + PMe,; iii Na/Hg; iv thf Scheme 6 Arylamido molybdenum complexes can be prepared from a dichloromethane solution of [Mo{HB(M~,~z)~}(NO)I~], where Me,pz = 3,5-dimethylpyrazolyl by addition of the appropriate arylamine.A series of such complexes of general formula " J. R. Dilworth P. L. Dahlstrom J. R. Hyde and J. Zubieta Inorg. Chim. Acta 1983 71 21. D. C. Bradley M. B. Hursthouse K. M. A. Malik A. J. Nielson and R. L. Short J. Chem. SOC.,Dalton Trans. 1983 2651. 186 J. E. Newbery [Mo{HB(Me2pz),)(NO)I(NHR)] where R = phenyl and various substituted phenyls has been characterized spectroscopically.83 No connection could be deter- mined between the v(N0) and the nature of the phenyl substituent. The NH protons appear in the 'H n.m.r. as sharp singlets (6 = 11.14-13.15 p.p.m.) and do not exchange with D20. Compounds of similar formulation but involving hydrazido ligands have also been synthesi~ed.~~ [Mo{HB(Me2pz),}(NO)I(NHNRRf)] shows octahedral geometry about the molybdenum for R = R' = Me and R = Me R' = Ph with a fac boron-ligand (a triple N-donor).The -NHNRR' group is unidentate in both cases with Mo-N-N = 140.3' and 144" respectively. A sealed-tube reaction between (*)-cis-[Cr(en),FCl]I and dry liquid ammonia gives rise to [Cr(en),FNH,]ICI in a cis-truns ratio of 4 1. This ratio was determined by h.p.l.~.~' The presence of trans product indicates that a trigonal bipyramidal complex is a likely intermediate. The polymeric [MO(NO)~CI~], can be used86 as a starting material for the produc- tion in dichloromethane solution of a range of neutral complexes Mo(NO),L2C12 (where L = MeCN PhCN PPh3 or py; L2 = bipy or diphos). The bipyridyl com- plex [Mo(NO),bipyCl,] has been studied by X-ray crystallography and shows an approximate octahedral arrangement with cis-dinitrosyls and trans-dichloros.The nitrosyls are roughly linear (175.9" and 177.4'). The chloro groups in this class of compounds can be displaced by stirring in 1,2-dimethoxyethane (dme) to yield8' the cations [Mo(NO),L,(dme)CI]+ and [Mo(NO),L2(dme),12+. Some of these have proven active as catalysts for the polymerization of norbornadiene. A rather fascinating bipyridyl complex formulated M~~Cl,(bipy)~ is produced" by direct action on Mo2C14(p-C1)2(p-H9C4-C~C-C4H9)(OPC13)2. An X-ray structural investigation showed that the action of the bipyridyl cleaves all the bridging units in the original complex to form a complex salt [cis-MoC12(bipy),]'[MoC1,(bipy)]- where both ions are octahedral.Formulations such as that make it quite hard to appreciate the mode of attachment in complexes such as Cr3L5C14.2H20 (L = purine or adenine).89 MoC1 will react with thiazylchloride to give a product" CI,Mo=N=SCl which is likely to be a dimer. Addition of POC13 produces a complex Cl,PO.Mo(Cl),NSCI and further treatment with chloride ion will give a complex anion [Cl,MoNSCI]-. An interesting series of simple mononuclear nitrosyl complexes of molybdenum has been prepared." Some data were obtained on their redox chemistry and the solid-state structures elucidated by X-ray diffraction. All showed a roughly linear disposition for M-N-0. As expected from their compositions mostly these were octahedral complexes but even so there were some points of interest.For example 83 J. A. McCleverty G. Denti S. J. Reynolds A. S. Drane N. El Mum A. E. Rae N. A. Bailey H. Adams and J. M. A. Smith 1. Chem. SOL Dalton Trans. 1983 81. 84 J. A. McCleverty A. E. Rae I. Wolochowicz N. A. Bailey and J. M. A. Smith 1,Chern. SOC.,Dalton Trans. 1983 71. 85 J. W. Vaughn Inorg. Chem. 1983 22 844. 86 D. Ballivet-Tkatchenko C. Bremard F. Abraham and G. Nowogrocki 1. Chem. Soc. Dalton Trans. 1983 1137. a7 D. Ballivet-Tkatchenko and C. Bremard 1. Chem. SOC.,Dalton Trans. 1983 1143. 88 E. Hey F. Weller B. Simon G. Becker and K. Dehnicke Z. Anorg. Allg. Chem. 1983 501 61. 89 C. M. Mikulski S. Cocco N. de Franco and N. M. Karayannis Inorg. Chim. Am 1983 80 L71. 90 U. Kynast and K.Dehnicke Z. Anorg. Allg. Chem. 1983 502 29. 9' A. Muller W. Eltzner S. Sarkar H. Bogge P. J. Aymonino N. Mohan U. Seyer and P. Subramanian 2. Anorg. Allg. Chem. 1983 503 22. Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn Tc Re 187 while [Mo(NO),(NCS),]'- and [Mo(NO)(H,O)C~,]~- are octahedral [Mo(NO) (H2N0)(NCS),]'-adopts a pentagonal bipyramidal configuration. In the preparation of related nitrosyl complexes x was never greater9* than 1.5 in MO(NO)~CI~(ROH) for a range of monofunctional alcohols. To achieve the co-ordination of two alcohol functions a diol was necessary e.g. [MO(NO)~C~~((CH~OH)~}]. Papers concerning oxygen-donor ligands and Group VI transition metals seem much less prevalent than those of either nitrogen- or sulphur-donors. Crown ethers do appear capable of stabilizing the rather elusive CrV oxidation state.If non-aqueous reduction of K2Cr207 is performed93 in the presence of 18-crown-6 Cr" is the most stable species generated. This was deduced from e.p.r. measurements. Cr" formation constants with a wide range of ligand types have been measured9 by potentiometric procedures. Ammonia ethylenediamine diaminopropane malonate glycinate p-alaninate iminodiacetate nitrilotriacetate and ethy-lenediaminetetra-acetate ligands were chosen for study. There were several dis- crepancies found from various previous compilations of data for Cr". In the present case the values obtained are compared to those of Cu'+ after taking account of the difference in ionic radii of the metals. As mentioned at the start of this section on Group VI transition metals naturally occurring chromium is found as Cr"'.Brewer's yeast contains chromium and the complexing entity could be either amino acids or nicotinic acid (3-carboxypyridine or niacin HL). Carboxylate binding is certainly very strong with this ligand-metal-ion combination and the solid-state structure of [Cr(HL)2(NH3)4](C104)3.2H20showsg5 it to have doubly protonated trans-pyridiniumcarboxylate groups. Each carboxylate acts in a monodentate fashion. The angle across the centre (0-Cr-0) is virtually linear (172.0'). Complete separation of the A and A isomers of Cr(a~ac)~ was achieved96 by h.p.1.c. methods in ca. 15 minutes. A chiral packing material (+)-poly(triphenylmethy1 methacrylate) was used and the best separation was attained by using 80% methanol-20% water as the eluting solvent.The range of complexes utilising sulphur donation is certainly much wider than that of oxygen. A number of different MoIV complexes involving S-bonded ligands has been prepared and their i.r. 13C n.m.r. and charge-transfer spectra mea~ured.~' Evidence is obtained for extensive formation of covalent bonds for example amongst the eight-co-ordinate dithio acid complexes of MoIV. Very efficient mixing of metal- ligand orbitals is probable since it was observed that the d-d transitions are buried under the charge-transfer bands n-back-bonding is also present. MoCl,(thf)z is a useful starting point for the synthesis of sulphur donor com- plexes. For example the sterically hindered thiol ligand (SC,H,Pr',)- as a sodium salt will react98 with it under a carbon monoxide atmosphere to produce [Mo(CO)~(SC~H~P~',),]-.The i.r. spectrum showed a single band in the v(C0) region at 1830 cm-I and is consistent with a trigonal bipyramidal structure having 92 L. Bencze J. Kohan and B. Mohai Acta Chim. Acad. Sci. Hung., 1983 113 183. 93 M. Mitewa P. Russev P. R. Bontchev K. Kabassanov and A. Malinovski Inorg. Chim. Acta 1983 70 179. 94 K. Micskei F. Debreczeni and I. Nagypal J. Chem. Soc. Dalton Trans. 1983 1335. 95 J. C. Chang L. E. Gerdom N. C. Baenziger and H. M. Goff Inorg. Chem. 1983 22 1739. 96 Y. Okamoto S. Honda E. Yashima and H. Yuki Chem. Lerr. 1983 1221. 97 J. Selbin Inorg. Chim. Acta 1983 71 201. 98 J.R. Dilworth J. Hutchinson and J. A. Zubieta A Chem. SOC.,Chem. Commun. 1983. 1034. J. E. Newbery the carbonyls in the axial position. This has been confirmed by X-ray crystallography. The structure shows two of the ligands in an endo configuration to one of the carbonyls and the other ligand ex0 to the same carbonyl hence reducing the steric clash from having three endo-groups. Another reaction of MoCl,(thf) is with 99 the tetradentate dithiol/thioether (LH,) to produce the complex MoCl,(L) (1 8) as dark violet crystals. A bridged species LMo(S),MoL can be produced on further reaction with sodium sulphide. (18) (19) An even more exotic ligand can be generated from the introduction of dimethyl-2- butyndioate to MoSZ- in warm acetonitrile.'" The sulphide anion has the structure {(S,),MOS}~- and reaction with the carboxyethyne opens up the S rings to produce the trigonal prismatic species [Mo{S~C~(CO,M~)~},]~- shown in (19) with only one of the ligands in full format.The s6 co-ordination polyhedron shows only minor discrepancies from D3,,symmetry with a mean S-Mo-S interligand trans angle of I35". A useful synthetic route to the MoIV dithiocarbamates (L-) MoL complexes has been published."' It is suggested that oxidative decarboxylation of Mo(CO) pro- duces high yields of the Mo'" species. Corresponding MoV' compounds are pentagonal bipyramidal; in [MoO(S,CNR,)J+ two of the dithiocarbamates are equatorial and the third has one axial sulphur and the other equatorial. The original assignment of this structure (R = Et) was for the solid state.With R = Me Et or Pr' the I3Cn.m.r. spectra have now1' been recorded and all are consistent with the structure being retained in solution. The presence of the Mo-0 anisotrophy helps in the assignment of resonances. The seeming preference of Group VI transition metals for sulphur is perhaps nowhere more important than in the attempts to establish the role of molybdenum in nitrogenase. As part of this effort a series of sulphur-donor/phosphorus-donor complexes have been prepared.lo3 The complexes [MoX2( S2CNR2)2(phos)2] where X = C1 or Br; R = Me, Et, or (CH,),; and (phos) = PPh,Me PMe2Ph PEt2Ph or i(Ph2PCH2CH2PPh2) were prepared from the MoOX2(S,CNR2) dithiocarbamate complex by direct action of the phosphorus ligand in thf.These are air-stable but 99 B. B. Kaul and D. Sellmann 2.Naturjorsch. Teil B 1983 38 562. loo M. Draganjac and D. Coucouvanis J. Am. Chem. Soc. 1983 105 139. I01 R. Lozano E. Alarcon A. L. Doadrio M. C. Rarnirez and A. Doadrio Anales de Quimica 1983,79,41. I02 C. G. Young,J. A. Broomhead and C. J. Boreham J. Chem. Soc. Dalron Trans. 1983 2135. I03 J. R. Dilworth B. D. Neaves C. J. Pickett J. Chatt and J. A. Zubieta Inorg. Chem. 1983 22 3524. Ti,Zr Hf;V Nb Ta;Cr Mo W;Mn,Tc Re can be reduced by t-phosphines in methanol to give cationic complexes [MOX(S~CNR~)~(~~OS)~]-, which although paramagnetic are e.p.r.-silent. X-Ray crystallographic analysis of two of these cations indicates pentagonal bipyramidal structures In both cases the dithiocarbamates are equatorial.The occupancy of the axial positions depends upon the nature of the phosphines. The chelating diphosphine is attached at one axial position and one equatorial whereas the bis(monophosphine) case has both phosphines in axial positions and an equatorial chlorine. Controlled potential electrolysis of such cationic species is a 2e process and under CO a species [Mo(CO)(S,CNR,),(diphos)] can be isolated. No evidence for similar N2 binding could be observed. Rather special dithiocarbamates can be obtained by incorporating the alkyl substituents and the nitrogen into one entity for example as pyrolle-N-carbodithionate (pdc). Reaction of MoCl with K(pdc) yields'04 a dark blue crystal- line solid that shows no i.r.band corresponding to Mo-0. Analysis shows it to be Mo(pdc) and X-ray diffraction data confirm the eight-co-ordinate structure. Such stoicheiometry is not unusual; what makes this compound unique is the mode of preparation. Under similar conditions most other S2CNR2 ligands would have produced a complex based on an Mo203core. The aryl dithiocarbamates seem able to stabilize the lower metallic oxidation states. Starting from Mo(CO),(pdc) it is possible to replacelo5 the carbonyls with alkynes to yield Mo(R'C,R),(pdc),. An alternative path starting from [Mo(CO),I]- where the previous carbonyl complex was not actually isolated is also described. These alkyne complexes are roughly octahedral with two bidentate (pdc) groups and two cis-parallel alkynes.'HN.m.r. spectra were taken at different temperatures and evidence obtained for two distinct fluxional processes. The rotation about the C-N bond (in the ligand) has AG' = 45 kJ mol-I and rotation of the alkynes (around the molybdenum-alkyne bond axis) has AG* = 57 kJ mol-'. Some complexes containing 0-,N- and S-donation have been described.lo6 The molybdo-oxaziridines (20) are prepared from reacting Mo02(S2CNEt2) with RsNHOH. A le reduction process was found in acetonitrile solutions and the observed potential appears to correlate with the Hammett parameters of the sub- stituent X. A further use for the dioxomolybdenum dialkyldithiocarbamate species used above is to react itio7 with an alkyl dithiocarbazate {NH,NHC(S)SR'}. The S\R' S4 N -SR' (20) X = H Me or CI R.D. Bereman D. M. Baird C. T. Vance J. Hutchinson and J. Zubieta Inorg. Chern. 1983 22 2316. I05 R. S. Herrick S. J. Nieter Burgmayer and J. L. Templeton Inorg. Chem. 1983 22 3275. I06 P. Ghosh P. Bandyopadhyay and A. Chakravorty J. Chern. SOC.,Dalton Trans. 1983 401. I07 R. Mattes and H. Scholand Angew. Chem. Int. Ed. Engl. 1983 22 245. 190 J. E. Newbery product obtained has the formulation [Mo{ N2C( S)SR'){NH,NC( S)SR'){S,CNR2)2] and a pentagonal bipyramidal co-ordination framework (2 1). The axial diazenido group is virtually linear (Mo-N-N = 178") and with Mo-N = 177 pm and N-N of 121 pm must have a considerable degree of electron delocalization. Finally amongst the sulphur-donor mononuclear complexes it is worth recording the synthesis and structural characterization of an all-sulphur donor compound [Mo{S,P(OMe),),].This was prepared'" by the addition of (NH4)S,P(OMe)2 to the Mo"' reduction product obtained from tin-reduction of MoCl,(thf),. 4 pseudo-octahedral environment was observed with the Mo-S distance ca. 2.51 A. Most of the halogen-donor complexes are dealt with under other headings and perhaps the only point of interest this year is the sugge~tion'~~ that an ill-defined shoulder in the electronic spectra of trans-dihalogen complexes is indicative of that orientation. This was noted particularly for trans-Cr(en)F,(H,O),. The shoulder is absent in trans-diaquo and trans-halogenoaquo complexes. The Group VI transition metals form an extensive range of complexes with macrocyclic ligands with most current interest centred on porphyrin adducts.The synthesis of nitrido(tetra-p-tolyIporphinato)chromium(v) is reported by two different groups. ' If hypochlorite oxidation of Cr(OH)(ttp).2H20 in a two-phase mixture of CH2C1,-NH3(aq) is allowed to proceed until the colour changes from green to red (ca. 4 h) the organic layer will contain the nitrido complex in 55% yield; the complex CrN(octaethy1porph) was prepared in a like manner.'" A similar yield was obtained' l1 for a photochemical reaction on Cr(ttp)N in methylene chloride (18 h reaction time) but the yield rose to 82% usingobenzene as a solvent. As expected the chromium was found to be slightly (0.42A) above the average plane of the pyrolle nitrogens.The Pitrido-chromium distance is consistent with that expected for a triple bond (1.56 A). MoVO(tpp)Br will react with the superoxide ion 05,to give MoiVO(tpp). If the reaction is carried out at -72 "C an intermediate complex can be recognized,'12 and evidence is presented to support the formulation of this stage as a dioxygen complex. This evidence comes partly from an examination of the e.s.r. spectra at different temperatures since if the intermediate is [Mo'"O(tpp)O,]- it will be diamagnetic and e.s.r.-silent. This was observed at -80 "C but raising the temperature allowed the lines from MoV to reappear and then eventually to decay as the final (diamagnetic) complex MoTVO( tpp) was generated. Mo'~porphyrins are often bridged species such as the [M~'~Cl(tpp)],.O complex which has each molybdenum displaced out of the plane and towards the bridging oxygen.' l3 Bridged Compounds.-The classification within this section is based around the nature of the bridging entity; obviously some appear under other headings but those included here are bridged compounds of special interest.Io8 J. R. Dilworth and J. A. Zubieta J. Chem. Soc. Dalton Trans. 1983 397. I09 J. W. Vaughn J. Cryst. Spectrosc. Res. 1983 13 231. 110 J. W. Buchler C. Dreher K.-L. Lay A. Raap and K. Gersonde Inorg. Chem. 1983 22 879. Ill J. T. Groves T. Takahashi and W. M. Butler Inorg. Chem. 1983 22 884. 112 T. Imamura K. Hasegawa and M. Fujimoto Chem. Lett. 1983 705. I I3 J. Colin B.Chewier A. De Cian and R. Weiss Angew. Chem. Int. Ed. Engf. 1983 22 247. Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn,Tc Re m The molecule Cp(CO)2W(NNMe)Cr(CO)s for example has been shown to have an N,N'-bridging diazo ligand,'I4 (22). The angle W-N-N is almost linear (174.4') but Cr-N-N is at 122.3'. One feature ofthis molecule is that although the structural parameters about the chromium are entirely typical for Cr(CO),L those of the tungsten centre seem to be altered significantly by the presence of another metal. Nitrogen-bridging by phenylimido groups is shown"5 in the dimer { W(NBu') (~-NP~)C~,(BU'NH~)}~. This has rather unsymmetrically situated phenylimido groups and is notable for the hydrogen-bonding type of interaction involving two of the chlorides (23).CP I H Crystals suitable for X-ray diffraction analysis were obtained from {(p-OH) Cr(NH3)4}2.(S206)2 by an interesting technique.' l6 Taking the corresponding bromide dimer a hydrobromic acid solution was covered in gel made from a 'standard preparation available in any Danish grocery store'. When the gel was almost set a saturated solution of Na2S206 was poured over and after two days in the dark suitable crystals were obtained. The compound is clearly rather diverse since at least five different modifications were recognized each with a separate X-ray powder pattern. The geometry about each metal is roughly octahedral with cis-hydroxo bridges and four terminal ammines. Oxygen-based bridges seem to be very common in molybdenum chemistry and there are reports involving a wide range of ligating types.The compound Mo,O,.(dmso) exists as infinite chains of Mo-0 polyhedra. It can be produced by work-up of Mo03.H20 in dimethylsulphoxide.'" It has two types of molybdenum environments a tetrahedral and an octahedral. These are then linked in repeating units as (-oct-tet-oct-oct-tet-oct-),. The Mo-0-Mo angle between two octahe- dral sites is 175.3' whereas between oct-tet it is 156.7". Two other variations of Mo03(dmso). with x = 1 or 2 were also identified by thermogravimetric analysis and probably consist of all octahedral and of (oct-tet) , respectively. The dinuclear molybdenum(v) glycinate complex M~,O,(gly)~( H20)2,has been shown'" to be stable in solution (>pH 5.5) for at least 24 h.Cyclic voltammograms were used to detect the presence of a dimeric MoV-MoV' species which displays I14 G. L. Hillhouse B. L. Haymore S. A. Bistram and W. A. Herrmann Inorg. Chem. 1983 22 314. I5 D. C. Bradley R. J. Errington M. B. Hursthouse A. J. Nielson and R. L. Short Polyhedron 1983,2,843. I16 S. J. Cline D. J. Hodgson S. Kallesoe S. Larsen and E. Pedersen Znorg. Chem. 1983 22 637. I I7 E. M. McCarron 111 and R. L. Harlow I J. Chem. Soc. Chem. Commun. 1983 90. I I8 M. Chaudhury J. Chem. SOC.,Dalton Trans. 1983 857. J. E. Newbery an electronic absorption band at 850nm. Efforts to isolate this entity have so far proved unsuccessful. A single 0x0-bridge between two octahedral molybdenums normally gives a virtual linear Mo-0-Mo angle.It is probable"' that it is the presence of rather bulky groups that is responsible for the angle of 171.0' found in [{MoHB(Me2Pz)3(No)I},01. A series of complexes involving various derivatives of 8-quinolinol (LL) with general formula (LL)2.Mo203S has been described.12' 1.r. spectroscopy was used to identify the presence of Mo=O and from other spectroscopic trends plus the rather low value for the magnetic moment it is suggested that these substances are dimeric with a p-0,p-S linkage. [Mo,( NO),(S,),( S,) (0H)l3- was obtained'" after prolonged reaction between {Mo(NO)}~+ complexes and Si-. It has an unusual structure (24) where if the centre bridging atom is included the Mo-S5- Mo-S ring has crown-like orienta- tions very similar to cyclo-octasulphur.The molybdenum atoms are roughly pen- tagonal bipyramidal. (24) (25) MOOS:-reacts'22 with FeCl and sulphur (S,) in dimethylformamide to produce the anionic complex [C12FeS2MoOS2]2- which has been characterized by X-ray structural analysis and a variety of spectroscopic procedures. It has the structure shown in (25) with two p-sulphido ligands. The "Fe Mossbauer spectrum is characteristic for Fe" high-spin tetrahedral complexes formed from ligands with strong acceptor properties. Reacti01-1'~~ between [CpMo(CO),J and Zn(S3CPh)2 forms two molybdenum complexes involving the dithiobenzoate ligand a monomeric complex CpMo(CO),(S,CPh) and a dimer {CpMo(S)S,CPh},. The structure of the latter species has been investigated by single-crystal X-ray crystallography and shown to belong to a new structural class for Mo'".It has a disulphido bridge and the S,CPh' groups are each bidentate to one metal. Finally in this section on bridged species there are a large number of papers involving MS groups in what could be described as a ligating mode to another metal. These are arranged in ascending order of ligand number. One reason for the popularity of these studies is the range of thiomolybdates that are found in bioinor- ganic studies. For example a recent study has suggested that the thiomolybdate I19 H. Adams N. A. Bailey G. Denti J. A. McCleverty J. M. A. Smith and A. Wtodarczyk J. Chern. Soc. Dalton Trans. 1983 2287. I20 R. Lozano J. Roman E. Alarcon A. L. Doadrio and A. Doadrio Lopez Anales de Quimica 1983 79 187.121 A. Miiller W. Eltzner H. Bogge and E. Krickemeyer Angew. Chem. Znt. Ed. EngL 1983 22 884. 122 A. Miiller S. Sarkar H. Bogge R. Jostes A. Trautwein and U. Lauer Angew. Chem. hi. Ed. Engl. 1983 22 561. 123 W. K. Miller R. C. Haltiwanger M. C. VanDerveer and M. Rakowski DuBois Inorg. Chem. 1983.22 2973. Ti Zr Hf;V Nb Ta; Cr Mo W;Mn Tc Re species present in rumen is more likely124 to be MoSi- than MOOS;-. The anion [MoS~(CUX)~]~-= C1 or Br) can be prepared by admixture of MoSZ- and CuX (X in the correct stoicheiometric ratio in acetone solution.'25 This represents the largest metal-uptake so far recorded for a cluster species based on MoS$- and may be important in aspects of copper antagonism in ruminants.The anion is polymeric based on the unit shown in (26). Four copper atoms are bound to each edge of the MoS~core. The Cu(p2-Br)Cu bridges alternate along the cbain between two types. One involves four bonds of similar length (2.50 * 0.05 A) while the other has significant differences (2.33 2.93 2.33 and 2.79 A).Thus the ion is best described as a dimer of the [MoS4(CuBr),J2- unit. Br I cu Many of these type of anions appear as dark-red or even black and this is probably a result of sulphur + metal charge-transfer bands,'26 red-shifted from those of the parent MoS:-ion.'*' When MSZ- ions act as ligands to a five-co-ordinate metal site they are normally attached cis to the basal plane of a square pyramid. In the complex S2W(p- S)2W(NNMe2)2.PPh3 however it is probably'28 the presence of the strong .rr-bonding ligands that gives a trigonal bipyramidal arrangement about the tungsten with the hydrazido groups in equatorial sites.The WSf group is thus forced to span axial and equatorial positions and is consequently somewhat distorted (W-p-S of 2.40 and 2.53 A for example). The expected chain structure with all the metals in tetrahedral sites is observed'29 for [S2W(p-S)2Fe(p-S)2WS2J3-. The bridges are very uniform and there is a ca. 9" bend along the spine of the anion. Considerable charge delocalization from the iron is observed from analysis of the iron Mossbauer spectrum. The corresponding molybdenum species has been synthesized and it possesses an e.p.r. spectrum similar to that of the Mo-Fe protein in nitrogenase.The ultimate chic in thiometallates of Group VI is undoubtedly amongst the cubane-like structures which have a core of alternate metal and sulphur atoms arranged in a rather distorted cuboid. I24 T. T. El-Gallad C. F. Mills I. Bremner and R. Summers J. Znorg. Biochem. 1983 18 323. IZ5 J. R. Nicholson A. C. Flood C. D. Garner and W. Clegg J. Chem. Soc. Chem. Commun. 1983 1179. 126 R. J. H. Clark T. J. Dines and G. P. Proud J. Chem. SOC.,Dalton Trans. 1983 2299. 127 S. R. Acott C. D. Garner J. R. Nicholson and W. Clegg J. Chem. Soc. Dalton Trans. 1983 713. IZ8 J. R. Dilworth R. L. Richards P. Dahlstrom J. Hutchinson S. Kumar and J. Zubieta J. Chem. SOC. Dalton Trans. 1983 1489. I29 J. W. McDonald G.D. Friesen W. E. Newton A. Muller W. Hellmann U. Schimanski A. Trautwein and U. Bender Znorg. Chim. Acta 1983 76 L297. I3O G. D. Friesen J. W. McDonald W. E. Newton W. B. Euler and B. M. Hoffman Inorg. Chem. 1983 22 2202. 194 J. E. Newbery The reaction between [Mo(NC6H,Me)(p3-S)(s2P(OEt),)] and S2CN(Pr') was found13* to give a mixture of yellow and red crystals. By correct choice of recrystalliz- ation solvents it proved possible to isolate pure samples of each. The yellow compound is a dimer [Mo(NC6H,Me)(p-S)(S2CN(Pr'),)l and the red is a tetramer having the same empirical formula. The structures of these are shown in (27) and several features are essentially identical between the two examples (e.g. angles Mo-S-Mo and S-Mo-S and distances Mo-N and Mo-S).The main difference comes in the Mo-Mo separation which lengthens to 2.88 in the tetramer from 2.81 A in the dimer. R R;NC/S\Mo/S\Ma=S~~NR; 's' I 's' I NR NR S -M0- 'I NR (27) Four cubane species of formula {Cu,MS,Cl}(PPh,),(E) where M = Mo or W and E = 0 or S have been shown to be isomorph~us.~~~ The core of {Cu,MS,Cl} has each copper co-ordinated by a phosphine and the S (or 0)attached to the Mo (or W). These can thus be regarded as complexes formed by MSZ-ligands. A classification is presented' 33 of various interrelationships in structures and reactivities for clusters containing the grouping {MoFe,S,}. Various pseudo-substrate ligands that are good (T donors and/or 7~ acids were used to examine patterns in binding at cubane surfaces.Fluxionality of the clusters depends on the lability of the Mo-L binding. In the cluster [MoFe,S,(SPh)3(diallylcatecholate)L]2-*3~ the binding affinity order at the molybdenum site is RS-< PEt < CN-. The core {M2Fe2S4} is also possible and can be produced'34 for M = Cr or Mo by irradiating in thf solution as shown in Scheme 7. Evidence for this transformation is mainly spectroscopic based on mass spectrometry ' H n.m.r. and i.r. spectroscopy. Molybdenum K-edge extended X-ray absorption fine structure (EXAFS) analysis is the main tool used in identifying some of these cubane systems with active centres that are found in nitrogenases. A number of these model compounds were compared with MoFe nitrogenase protein.135 In general shape the best agreement between the Fourier transforms was found for [C1,FeS,MoS2FeC1,]*- but there was a gross mismatch in terms of peak intensity.[M~,Fe,s,(sEt),]~- a double cubane gave a reasonable intensity match but was less convincing on peak shape. Matching peaks obtained from EXAFS could well be a rather tricky occupation. A technique for fine adjustment based on models (FABM) has been des~ribed',~ to improve the 131 K. L. Wall K. Folting J. C. Huffman and R. A. D. Wentworth Inorg. Cfiem. 1983 2366. 132 A. Muller H. Bogge and U. Schimanski Inorg. Chem. Acta 1983 69 5. 133 R. E. Palermo and R. H. Holm J. Am. Chem. SOC.,1983 105 4310. 134 H. Brunner H. Kauermann and J. Wachter Angew. Chem. In&. Ed. Engl 1983 22 549. 135 B.-K.Teo M. R. Antonio D. Coucouvanis E. D. Simhon and P. P. Stremple J. Am. Chem. SOC.,1983 105 5767. 13' B.-K. Teo M. R. Antonio and B. A. Averill J. Am. Chem. SOC.,1983 105 3751. Ti,Zr Hf;V Nb Ta;Cr Mo W;Mn Tc Re S\ either Me,C,-CCr-/p'Cr-C,Me5 or "Cp' Scheme 7 comparative nature of these measurements. Correctly applied it is shown capable of determining Mo-S data (interatomic distances and co-ordination numbers) to at least 10% accuracy. Results from EXAFS will remain model-dependent unless they are established by reference to a model of proven suitability. The cubane [M02Fe&i+,]3- (L = SCH2CH,0H) catalyses the controlled poten- tial reduction of N3 and hydrazine to ammonia 1377138with the concomitant evolution of hydrogen.Hydrogen evolution occurs also from dimethylacetamide solutions of the reduced clusters [M~~Fe,s~(sPh),]~-'~- and benzenethiol. 139Absorbance changes (AA) during this evolution were found to fit best the equation AA480 = c,[PhSH] + C,[P~SH]~/*~'/~ where c1 and c2 are constants and t is the time. Taking account of the behaviour of the (4-) and (5-) anions a kinetic rate equation based on a common intermediate (Im)was developed d[H,]/dt = k[I,][PhSH]. Metal-Metal Bonded Compounds.-Reactivity in the alkoxides of tungsten and molybdenum forms the basis of a recent review.'40 There are over 90 references to these compounds with specific relevance to M-M and M-C bonding. The various types of reaction are related to the structural mores of the alkoxides.Generalized molecular orbital and configuration interaction calculations have been performed on a progression of diatomic molecules and on Mo~H,.'~' The derived potential energy curve shows a minimum at a realistic value of 2.194 A and the dissociation energy is estimated as 284 kJ mol-I (MorMo). For the molecule Mo2(NH& a value of 401 kJ mol-' is obtained. The increased bond strength reflects the .rr-donation ability of -NH2. I37 Y. Imasaka K. Tanaka and T. Tanaka Chem. Leu. 1983 1477. 13* Y. Hozumi Y. Imasaka K. Tanaka and T. Tanaka Chem. Lett. 1983 897. I39 T. Yamamura G. Christou and R. H. Holm Inorg. Chem. 1983 22 939. I40 M. H. Chisholm Polyhedron 1982 2 681. R. A. Kok and M. B. Hall Inorg. Chem. 1983 22 728. 196 J.E. Newbery The addition of alcohols to hydrocarbon solutions of 1,~-MO~R~(NM~~)~ gives either 1,2-Mo2R2(OR’) or MO,R(OR’)~ where the rate of the process is markedly dependent upon. steric factors. The replacement of the alkyl group also is much slower than alcoholysis of the amide. The molecule 1,2-Mo,Me2(OBu‘) will take up 2 moles of pyridine and the resultant species142 has been shown to have Mo-Mo of 2.256 A. It is roughly square pyramidal about each metal with one molybdenum occupying the position axial to the other. When the R group is small the alcoholysis reaction proceeds to completion and eventually gives Mo2(OR‘),. With bulky alkyl groups (CH2CMe3 CH2SiMe3 etc.) it becomes possible to isolate species MO~(R)~(OR’), and even the mixed ligand complex MO,(CH~CM~~)~(NM~~)~(OP~~)~.As mentioned previously molybdenum shows a great propensity for sulphur- donor ligands and the preparation of unbridged metal-metal bonded compounds containing monodentate -SR ligands represents a skilful piece of synthetic chemistry.143 Starting from Mo,(NM~~)~ direct addition of (C6H2Me3)SH allows the replacement of only four of the amido groups. A similar process occurs with Mo(OR) as a starting material. However if the complex 1,~-MO,(SBU‘)~(NM~~), is taken addition of the thiol now leads to the production of the desired homoleptic species An X-ray crystallographic analysis confirms this formula- tion and shows themmolecule to be ligated symmetrically with an unbridged Mp-Mo distance of 2.228 A.If (thf)3Li.Sn(SnMe3)3 in hexane is added to a suspension of Mo2C12(NMe2), a heterobimetallic complex is formed with retention of the Mo=Mo bond.’44 Mo2(Sn(SnMe3),},(NMe2) has been studied by X-ray structural methods and shows the usual Mo,X2(NMe2) arrangement of tetrahedral molybdenums with the molecule in the anti conformation. ‘Hn.m.r. evidence supports the retention of this confErmer in benzene solution. Mo-Mo was found to be 2.20 A and Mo-Sn was 2.78 A. Substitution reactions on these M2L6 species usually lead to either cleavage or retention of the M-M bond. For example Mo,(NMe,) will react with 2,6-dimethyl- phenol (HOAr) to give MOz(OAr)6. Use of 4-methylphenol gives14s the complex [H2NMe2]’[Mo2(OAr’),(HNMe2)2]-. An X-ray crystallographic study shows this to possess the overall geometry of a confacial bi-octahedron with terminal amine ligands and three bridging phenoxide ligands (28).The Mo-Mo bond length becomes 2.60 A. The formation of such a different product from a seemingly trivial change in the nature of the phenol raises several interesting points concerning reactivity in this class of compounds. Ar’ Ar’ \I Ar’q ,,\O PAr’ Me,HN-Mo-Mo-OAr’ Ar’d ‘()A \NHMe, I Ar ’ (28) 14* M. H. Chisholm J. C. Huffman and R. J. Tatz J. Am. Chem. Soc. 1983 105 2075. 143 (a) M. H. Chisholm J. F. Corning and J. C. Huffman J. Am. Chem. SOC.,1983 105 5924; (b) M. H. Chisholm J. F. Corning and J. C. Huffman Inorg. Chem. 1983 22 38. I44 M. J. Chetcuti M. H. Chisholm H. T. Chiu and J.C. Huffman J. Am. Chem. Soc. 1983 105 1060. I45 T. W. Coffindaffer I. P. Rothwell and J. C. Huffman Inorg. Chem. 1983 22 3178. Ti,Zr Hf;V Nb Ta;Cr Mo W;Mn Tc Re 197 Gas-phase X-ray photoelectron spectroscopy was used'46 to evaluate core-electron ionization energies in a number of metal-metal tetra-p-carboxylates (M2L4). Ab initio calculations were used to support a model for the metal-metal separations. It was suggested that there is a correlation between the separation and both core and valence metal ionization energies. The large range of Cr-Cr separations in such compounds results from variation in the electrostatic potential at the metal due mainly to the differing charge on the ligands. An example of one of the longer Cr-Cr separations is given in the reported ~tructure,'~' determined by X-ray crystallographic methods of Cr2(02CMe)4(NCS)2.This has the familiar 'paddle-wheel' tetra-po-carboxylates with axial thiocyanates and a very long Cr-Cr separation of 2.467 A. During the course of investigations of the unstable W2C148- some violet crystals shown by analysis to be [W,C19](Ph,PNPPh3)2 were obtained. 149 The cation was characterized by crystallographic means and shown to be a confacial bi- octaeedron (i.e. with three bridging chloro atoms) The metal-metal seqaration was 2.54 A and the metal-chlorine distances were 2.45 A (bridging) and 2.35 A (terminal). The main point of interest here is the considerable lengthening in the W-W bond from that of 2.42 A found in the [W2Cl9I3- ion.This could be explained by suggesting that an increase in the formal metal oxidation number causes a contraction of the 5d orbitals and hence a weaker a-bond. Some of the possible products from reactions between W2(OR) compounds and alkynes are shown in Scheme 8. The cleavage reaction was reported in 1982 but W2(0Bu')6 (Bu'O) WECMe HCCH W2(0Pr')6(py)2 * excess R;C I W2(OPr')6(CL-C4Rk)(C2R:) W,(oR)6(py)(P-N[CMe14N) Scheme 8 the other information is of more recent origin. 150*15' Several noteworthy points arise from a consideration of these sterically-controlled reaction paths. The formulation W,(OR),(py),(p-C,R$) has quite different structures for (R = Pri R = H) and (R = CH,Bu' R' = Me). Whereas the former shows two bridging alkoxy groups the latter has only one and hence different co-ordination about each of the metals.The structure of the (p-C4R3 complex is shown in (29)' and could be viewed as I46 P. M. Atha J. C. Campbell C. D. Gamer I. H. Hillier and A. A. MacDowell J. Chem. Soc. Dalton Truns. 1983 1085. 147 P. D. Ford L .F. Larkworthy D. C. Povey and A. J. Roberts Polyhedron 1983 2 1317. I48 R. R. Schrock L .G. Sturgeoff and P. R. Sharp Inorg. Chem. 1983 22 2801. I49 F. A. Cotton L. R. Falvello G. N. Mott R. R. Schrock and L. G.Sturgeoff Inorg. Chem. 1983,22,2621. 150 M. H. Chisholm K. Folting D. M. Hoffman J. C. Huffman and J. Leonelli 1.Chem. Soc. Chem. Commun. 1983 589. 151 M. H. Chisholm D. M. Hoffman and J. C. Huffman J. Chem. Soc. Chem. Commun. 1983 967.J. E. Newbery C’c II’ Nc RO /C\ /,OR RO-W-W-OR 1 \OR R’C=CR’ R (29) the sum of two segments one having a diene co-ordinated and the other an alkyne. The (N(CMe),N)-containing molecule has the structure shown in (30),with a W-W single-bond distance of 2.617 A. The W-N distances in the N(CMe),N ligand are 1.78 and 2.09 A for the tungsten also bearing the pyridine) and 1.90 8 for the second tungsten. These are not dissimilar from that expected for terminal and bridging imido ligands. If MO,(OR)~(R = Pr’ or But) is reacted with benzoyl peroxide in hydrocarbon solution an intense blue coloration develops.’52 For the propoxy species a solid product was obtained that has a formula Mo~(OP~’),(O,CP~)~. The structure is based about a Mo-Mo double bond with two bridging (OPr’) groups.It is thus formed by edge-sharing octahedra. For R = But the eventual crystalline product was pale yellow-green and formulated MO~(OBU‘)~(O~CP~), where the triple bond has been retained and the 02CPh groups are responsible for bridging. A very interesting transformation occurs when ArN02 is reacted,Is3 under very mild conditions with the M-M triple bonded compound Mo,(CO)~(C~),. The carbonyl groups are expelled and a bridged compound (31) is formed with an Mo-Mo distance of 2.65 A. The decarbonylation process occurs with retention of the metal-metal bond although it drops to single-bond order. (31) (32) (33) Finally for bridged M-M quadruple-bonded complexes the synthesis of a homoleptic phosphide is ann0~nced.l~~ Mo2(p-But2P),(But,P) was produced as a red crystalline solid from the reaction of LiBu‘,P with Mo,(OAc) in diethyl ether.It is quite reactive decomposing rapidly in solution and on exposure to the atmos- phere. The bridging groups in the butterfly configuration (32) are symmetrical and Mo-Mo is 2.209 A. No P-P coupling between the bridged and terminal phosphorus nucleii was observed in the 31P n.m.r. spectrum. Reacting Mo~CI,(PE~~)~ with Me2PCH2CH2PMe2 gave a high yield of the bridged complex Mo,Cl,(diphos), (33) with idealized D symmetry. With an average torsion ‘52 M. H. Chisholm J. C. Huffman and C. C. Kirkpatrick Inorg. Chem. 1983 22 1704. I53 H. Alper J.-F. Petrignani F. W. B. Einstein and A. C. Willis J. Am.Chem. Soc. 1983 105 1701. I54 R. A. Jones J. G. Lasch N. C. Norman B. R. Whittlesey and T. C. Wright J. Am. Chem. SOC.,1983 IM.6184. Ti,Zr Hf;V,Nb,Ta;CryMo,W;Mn,Tc Re angle (x)of 40° the molecule is almost exactly staggered. The metal-metal bond is 2.18 A and is the longest found in compounds of similar stoicheiometry. Indeed it it possible to suggest that an inverse linear correlation exists between the Mo-Mo bond length and cos 2x. This could result from a lessening of the S2 contribution to the quadruple bond as the torsion angle is increased (and therefore as cos 2x decreases). The u27r4contribution is not sensitive to the torsion angle.15s Moving on to clusters containing three or more Group VI metals 95M0 n.m.r. data have been used to examine the nature of the Mo'" aquo Resonances from aqueous solutions of a range of different complexes known to contain the cluster Mo30:+ in the solid state are shown to have chemical shifts of a very similar magnitude.Additional features develop in the spectra after storage of the solutions in air. These are assigned to the formation of some Mo" species probably similar to (MO~O,)~'. A number of reactions of W,(OR) alkynes have already been noted (Scheme 8). If the t-butoxide complex is reacted with EtC2Et for three days at 74 "C a molecule containing six tungsten atoms is formed.'57 This has been formulated [W,(OBu'),(p-O)(p-CEt)O] on the basis of a single-crystal X-ray structural analysis. Each u!it contains a trinuclear tungsten cluster which has two long bonds (W-W ca.2.9 A) that are symmetrically bridged by either -CEt or -OBu' and one short unbridged bond (W-W = 2.42 A). The two trinuclear units are then linked by bis-oxo ligands. There are six electrons available for the metal-metal bonding with the units and bonds of order 2 1/2 and 1/2 might seem suitable. If a slight excess of trimethylphosphite is added to a methanolic suspension of &Mo2C1, the purple colour of the molybdenum salt slowly fades as a yellowish precipitate forms.15* This has the empirical formula MoCl,.P(OMe) and has now been shown to contain a cyclotetramolybdenum feature (34). The four metal atoms form a perfect but not quite rectangular plane (corner angles of 89.5" and 90.5'). (34) The bridged arms are longer than the unbridged (2.878 A and 2.226 A,respectively) and it is suggested that these represent single and triple bonds respectively.Finally in this section on metal-metal bonded compounds two examples are given from amongst the wealth of investigation into heterometallic entities. The titanium reagent (35) is known to add readily across alkyne linkages to form four-membered metallacycles. If it is mixed'59 with W(rCR)(CO),(Cp) such a reaction does not occur; instead a more complicated species (36) can be isolated 15' F. A. Cotton and G. L. Powell Znorg. Chem. 1983 22 1507. IS6 S. F. Gheller T. W. Hambley R. T. C. Brownlee M. J. O'Connor M. R. Snow and A. G. Wedd J. Am. Chem. Soc. 1983 105 1527. F. A. Cotton W. Schwotzer and E. S. Shamshoum Organomerallics 1983 2 1340.F. A. Cotton and G. L. Powell Inorg. Chem. 1983 22 871. I59 R. D. Barr M. Green J. A. K. Howard T. B. Marder I. Moore and F. G. A. Stone J. Chem. SOC. Chem. Commun. 1983 746. 15' 200 J. E. Newbery in which (35) appears to have undergone an insertion reaction in the Ti-C bond. This may be attained via a metallacyclobutene intermediate. A chain-type molecule involving five metal atoms has also been synthesized,’60 (Scheme 9). X-Ray structural analysis was used to ascertain the exact nature of the product at each stage of the stepwise addition of Pt-bis-(cyclo-octa- 1,5-diene) to W(-CR)(CO),Cp. Cp(OCLW /CR II PI II RC’ \W(CO)2Cp Scheme 9 0rganometallics.-The first species to be included here are the carbonyls.During matrix-isolation investigations involving chromium hexacarbonyl a sig- nificant interaction has been observed’61 between a Cr(CO)5 fragment and xenon. The species Cr(CO)sXe is sufficiently stable at -100 “C to allow identification by the characteristic pattern of carbonyl bands in the FT-i.r. spectrum. The anionic species [M(CO),X,]- (M = Mo or W and X = Br or I) can be prepared’62 by refluxing M(CO)5py with the appropriate halogen. If bipyridyl is now added the complex M(C0)3(bipy)X2 is produced. I 60 M. R. Awang G. A. Carriedo J. A. K. Howard K. A Mead I. Moore C. M.Nunn and F. G. A. Stone J. Chem. SOC.,Chem. Commun. 1983 964. 161 M. B. Simpson M. Poliakoff J. J. Turner W. B. Maier 11 and J. G. McLaughlin J. Chem. SOC.,Chem.Commun. 1983 1355. I62 J. R. Moss and B. J. Smith S. Afr. J. Chem. 1983 36 33. Ti Zr Hf;V Nb Tu;Cr Mo W;Mn Tc Re 20 1 Cr(CO)S(S02) has been studied by X-ray crystallographic methods and to have 7 I-co-ordinated sulphur dioxide. The carbonyls are virtually all equally distant from the metal and this is taken as proof of the high w-acceptor power of SOz. At 219 pm the Cr-S separation is one of the shortest reported. The compounds M(CO)5(SCH2SCH,SCH2SdH2)(M = Cr or W) have been by variable temperature n.m.r. and evidence has been collected for two intramolecular processes. There was no free ligand exchqnge and it seems likely that the processes are a pyramidal inversion about the co-ordinated sulphur atom (37) with an activation energy of 50 kJ mol-I and a 1,3 shift with E of 80 kJ mol-I.Both had AS* of near zero. (37) A series of W(CO),L sulphide complexes where L = R3ZSPh with R = Me or Ph and Z = C Si;Ge or Sn has been prepared.'65 These were studied by observing the y(C0) frequencies which change in response to alterations of the electron density on the sulphur. Several reports on n.rn.r. investigations of Group VI carbonyl complexes have appeared recently. 31P resonances in an extensive series of complexes of formulation W(CO),(PR,)(L) show'66 that the cis has a larger shift than the corresponding trans isomer. In the trans complexes the W-P coupling constant depends upon the nature of L; J decreases in the order SbPh3 <AsPh <PPh -P(OPh) <CO. I3C spectra for a number of Cr(CO)5L complexes a correlation between the oxidation potential and the I3C chemical shift.95M0 spectra have also been obtained16' and perhaps the most interesting is that while the 95M0 shifts seem to show very poor correlation with chemical shifts of other nucleii they do seem to correlate with A,, of the charge-transfer bands. The homoleptic complex Cr&(R = CPh=CMe,) is a green crystalline material that is relatively stable to the atmosphere. It can be formed17' by treating Li(CPh=CMe,) with CrC13.3(thf) and has been shown t? have an approximate tetrahedral structure with Cr-C distances of 2.98 f 0.02 A. Terminal methylidyne groups on tungsten have been shown to be not very willing to react with carbon monoxide unless aluminium reagents are also present.A complex formulated W(CH)(CO),(PMe3)3(C1)(A1X3) can be ~btained'~'from reacting W(CH)(PMe,),Cl with CO and AlMe (or A12C16). This has now been shown to 163 Ch. Burschka F.-E. Baumann and W. A. Schenk Z. Anorg. Allg. Chem. 1983 502 191. 164 E. W. Abel G. D. King K. G. Orrell and V. Sik Polyhedron 1983 2 1363. 165 C. R. Lucas Can. 1.Chem. 1983 61 1096. I66 W. A. Schenk and W. Buchner Inorg. Chim. Actq 1983 70 189. I67 A M. Bond S. W. Carr R. Colton and D. P. Kelly Inorg. Chem. 1983 22 989. I68 A. F. Masters G. E. Bossard T. A. George R. T. C. Brownlee M. J. O'Connor and A. G. Wedd Inorg. Chem. 1983 22 908. 169 G. M. Gray and C. S. Kraihanzel Inorg. Chem. 1983 22 2959. I70 C J. Cardin D. J. Cardin J. M. Kelly R.J. Norton A. Roy B. J. Hathaway and T. J. King J. Chem. Soc. Dalton Trans. 1983 67 1. 171 M. R. Churchill and H. J. Wasserman Inorg. Chem. 1983 22 41. 202 J. E. Newbery correspond to the structure (38) W( q2-HCrCOA1C13)(CO)(PMe3)3Cl.The q2-ligand has W-C distances (2.03 and 2.01 A) close to those of carbon-tungsten double bonds found in alkylidene complexes. It is also interesting to observe that the plane of the ligand is parallel to the bonding axis of the carbonyl group. 713 A1 I 0,C-CH OC:wyPMe3 \/ Me,P 1 PMe C1 (38) (C6Et6)Cr(C0)2CS has a ‘piano-stool’ structure in the solid state with the ethyl groups projecting alternately ‘up’ and ‘down’ around the ring.’72 The 13C n.m.r. spectrum in CD2C1 solution at 163 K is consistent with this conformation.As the temperature is raised the ring begins to rotate about the Cr-centroid axis with subsequent spectral alterations. The paramagnetic piano-stool molecule CpMo(Cl),(diene) will ~ndergo”~ the expected metathetical halogen exchange with TlSAr (Scheme lo) but an excess of reagent will expel the diene and produce a diamagnetic molecule CpMo(SAr),Tl. TlSAr (excess) (excess) nSAr 1 1 CP CP I I I SAr (B) Scheme 10 Two possible structures A and B are consistent with spectroscopic data. Thus for Ar =C6F5,19Fn.m.r. spectra show four inequivalent aromatic groups and evidence for exchange between bridging and terminal -SAr groups was obtained. One of the carbonyl groups in (C~)MO(CO),{[CH,]~B~} becomes incorporated into a cyclic three-electron ligand if the complex is treated with LiEt3BH in thf.I7 I72 M.J. McGlinchey J. L. Fletcher B. G. Sayer P. Bougeard R. Faggiani C. J. L. Lock A. D. Bain C. Rodger E. P. Kiindig D. Astruc J.-R. Harnon P. Le Maux S. Top and G. Jaouen J. Chem. Soc. Chem. Commun. 1983 634. ‘73 J. L. Davidson. K. Davidson and W. E. Lindsell 1.Chem. Soc. Chern. Cornmun. 1983 452. I74 H. Adarns N. A. Bailey P. Cahill D. Rogers and M. J. Winter J. Chem. Soc. Chern. Cornmun.,1983 831. Ti,Zr Hf; V Nb Ta; Cr Mo W;Mn Tc Re 203 The sotructure adopted is sho!n in (39) and both (Mo-C) (ring) and (Mo-0) are 2.16 A with C-0 (ring) 1.41 A. The Mo-0 interaction can be readily interrupted and thus the compound will take up 1 mole of PPh3 in high yield with the cyclic ligand remaining attached to the metal via the carbon alone.CP I H,C-CH2 (39) 5 Manganese Technetium and Rhenium A review has been written17' on the role of manganese in photosynthetic oxygen evolution. Mn207 has been known as a highly explosive substance for over 100 years and probably as a result of this property there is little known about its structure. Both i.r. and U.V. spectra have now been recorded'76 for matrix-isolated species at low temperatures. The spectra are consistent with a bridged 03Mn-0- Mn03 structure and v(Mn=O) was found at 995cm-' (asymm) and 890cm-' (symm) with v(Mn-0) at 775 cm-'. The bridge angle is probably around 155". EXAFS measurements were to suggest that aqueous solutions of MnBr2 have MnBr2(H20) present as the major species.This was achieved by a comparative method involving an examination of the aquo solution and of the crystalline compounds MnBr,.2H20 and MnBr2.4H20. Co-ordination Compounds.-These will be examined metal-by-metal in order of ligand complexity. There has been some controversy over the manganese(I1) complexes Mn(t-phos- phine)X2 concerning whether these species have any existence and if so whether they can bind oxygen reversibly. By releasing phosphine vapour on to a film of MnBr, changes in the i.r. spectrum could be observed.'78 These have been interpreted as strong evidence for the existence of the complex MnBr2.PMe,. No evidence could be found for reversible oxygenation but dioxygen is taken up as a superoxide species eventually giving rise to a phosphine oxide complex.There are no such status doubts concerning malate complexes of Mn". An X-ray crystallographic analysis of manganese( 11) (*)-1-malate confirms' 79 the expected octahedral environment about the metal with the ligand chain in the trans conforma-tion. There is hydrogen bonding present also and each malate ion has an interaction with three manganese centres. Not surprisingly I-cysteine proves to be a better ligand to manganese(") than the cysteine molecule with a methyl group substituted at the N S or ester positions.'80 Oxygen uptake occurs in solutions of the cysteine complex with the ligand eventually L.-E. Andriasson 0. Hansson and T. VanngHrd Chem. Scr. 1983 21 71.17' W. Levason J. S. Ogden and J. W. Tufi J. Chem. SOC.,Dalton Trans. 1983 2699. I77 B. Beagley B. Gahan G. N. Greaves and C. A. McAuliffe J. Chem. Soc. Chem. Commun. 1983 1265. 178 H. D. Burkett V. F. Newberry W. E. Hill and S. D. Worley J. Am. Chem SOC.,1983 105 4097. 179 A. T. H. Lenstra and J. Dillen Bull. SOC.Chirn. Belg. 1983 92 257. 180 R. K. Boggess J. R. Absher S. Morelen L. T. Taylor and J. W. Hughes Inorg. Chem. 1983 22 1273. 204 J. E. Newbery forming a disulphide. The manganese ion acts in a catalytic fashion probably through an Mn"'/02 species. Mn(NCS)2(pyrazole) has been shown by single-crystal X-ray diffraction to take the trans configuration."' The chemistry of technetium now yields almost as many papers for review as that of manganese.The production of stable Tc' complexes such as [Tc(CNR),]+ by Na2S204 reduction of the pertechnetate in the presence of the ligand has been reported.lS2 The method worked well for R = Me But cyclohexyl and Ph and only failed for R = H. The complexes are air and water stable and can be oxidized at ca. 0.85 V (versus SCE) for the alkyl and 1.18 V for the phenyl species. Synthesis of a number of Tc-substituted-thiourea complexes is reported. 183,184 The low-spin d5 Tc" complex TcCl,(NO)( PMe2Ph) can be readil~''~ prepared from TcCl,(PMe,Ph). E.p.r. data are interpreted as giving evidence for the mer-arrangement of chlorines with trans phosphine groups. Much of the interest in technetium is a result of its employment as an image- forming substance in nuclear medicine.Cationic complexes are thus of some poten- tial use in scanning body tissue such as the heart with a propensity for the accumulation of positively charged entities. A number of such complexes of general formula tran~-[Tc(diphos)~X~]+ = C1 Br or NCS) have been prepared.lS6 The (X corresponding Tc"' neutral compounds were also prepared. Reduction methods from TcCli- TcOCl ions were used in each case. Crystal structures on some octahedral rhenium compounds have been reported. 187-'89 ReI,O(OR)(PPh,), where R = Me or Et takes the all-trans form."' Perhaps the most interesting part of the structure is the I-Re-I bond angle which is 166.9' in the ethoxy case and 169.8' in the methoxy example. From a mixture of ReCl, (NSCI), and P0Cl3 both (Cl,PO)ReCI,NSCl and (C13PO)ReC13(NSC1)2can be isolated."' If the latter species is now treated with AsPh,Cl in dichloromethane a cationic complex [ReCl,(NSCl),]- is precipitated.This has cis-NSC1 groups with Re-N-S nearly linear (175.3' and 175.9') and the angles N-S-Cl of ca. 108". If ReCl,(NO) is reacted with triphenylphosphane (NPPh,) a complex involving triphenylphosphine oxide is produced.lS9 This has been characterized as ReCl,(NO)(NPPh,)(OPPh,) by P n.m.r. spectroscopy and X-ray crystallography. It shows mer-chlorines with the OPPh3 group trans to the bent nitrosyl (Re-N-0 = 174.1'). One interesting feature of Group VII chemistry is the wide amount of attention paid to complexes involving macrocyclic ligands.As well as being used for organ- imaging technetium compounds are possible chemotherapeutic agents. In this 181 P. Lumme I. Mutikainen and E. Lindell Inorg. Chim. Acra 1983 71 217. 182 M. J. Abrams A. Davison A. G. Jones C. E. Costello and H. Pang Inorg. Chem. 1983 22 2798. '83 U. Abram and S.Abram Z. Chem. 1983 23 228. I84 M. J. Abrams D. Brenner A. Davison and A. G. Jones Inorg. Chim. Acta 1983 77 L127. 185 R. Kirmse B. Lorenz and K. Schmidt Polyhedron 1983 2 935. '*' K. Libson B. L. Barnett and E. Deutsch Inorg. Chem. 1983 22 1695. 187 G. Ciani G. D'Alfonso P. Romiti A. Sironi and M. Freni Inorg. Chim. Acta 1983 72 29. I88 U. Muller W. Kafitz and K. Dehnicke Z Anorg. Allg. Chem.. 1983 501 69. N. Mronga F. WeIler and K. Dehnicke.2.Anorg. Allg. Chem. 1983 502 35. I89 Ti Zr Hf;V Nb Ta;Cr Mo W;Mn,Tc Re context the synthesis and tissue distribution of 99Tc tetrasulphophthalocyaninesis of some interest."' While there was little interaction with the stomach or thyroid useful amounts were found to be retained by the cortex of the kidney and also the liver. Possible interaction with tumours was also observed. R-N \ /"-" N N (40) A template synthesis involving the formation of the ligand shown in (40) is reported.'" The product was formed from the condensation of 2,9-di(N-2'-hydroxyethylhydrazin0)- 1,lO-phenanthroline with 2,6-diacetylpyridine in the pres- ence of maganese chloride. Mn(L)Cl has the metal co-ordinated by five of the ligand nitrogen atoms (0.51 A above their plane) and has the chlorine in the axial site.The strength of the manganese-nitrogen bond in nitridomanganese porphyrins is shown192 by the fact that it is possible to undertake reductive methylation on the octaethyl porphyrin complex and yet retain the MnEN bond. The methylated compound shows Mn-N of I .5 12 A. Mn'"(tpp)(L), where L = N; or NCO- and tpp = tetraphenylporphinato can be made"' from Mn(tpp)(OMe) by reaction with either Me,Si.N or HNCO. The complexes are rather unstable but it proved possible to show that the isocyanato species is roughly octahedral about the manganese. There is considerable 'ruffling' of the porphyrin core which may be a result of crystal-packing constraints; Mn-NCO is 1.93 A. Oxygen-transfer is an obvious area of interest for porphyrin species.Treatment of a dichloromethane solution of Mn(tmp)Cl where (tmp) is tetramesitylporphinato by aqueous sodium hypochlorite in the presence of a phase-transfer agent caused the initially green organic layer to turn brown.194 [Mn(tmp)O]Cl is rapidly reduced back to the Mn"' starting complex. It will however react with both styrene or triphenylphosphine to give the appropriate oxide. Mn"'(tmp)CI can also be reacted with potassium superoxide (in acetonitrile- crown ether) to give195 Mn"(tmp)O,. Both species have been shown capable of fitting into a complete catalytic scheme involving acylation and also oxygen-transfer to olefins (Scheme 11). 1.r. spectra have been obtained for Mn(oep) and Mn(oep)O, where oep = octaethylporphinato by the matrix-isolation method.19' The v( 1602) peak occurs at I YO J.Rousseau D. Autenrieth and J. E. van Lier Inf. J. Appl. Radiaf. Isor. 1983 34 571. 191 C. W. G. Ansell J. Lewis P. R. Raithby and T. D. O'Donoghue J. Chem. Soc. Dalton Trans. 1983 177 192 J. W. Buchler C. Dreher K.-L. Lay Y. J. A. Lee and W. R. Scheidt Inorg. Chem. 1983 22 888. I93 M. J. Camenzind F. J. Hollander and C. L. Hill Inorg. Chem. 1983 22 3776. 194 0. Bortolini and 8. Meunier J. Chem. Soc. Chem. Commun. 1983 1364. I95 J. T. Groves Y. Watanabe and T. J. McMurry J. Am. Chem. Soc. 1983 105 4489. 196 T. Watanabe T. Ama and K. Nakamoto Inorg. Chem. 1983 22 2470. J. E. Newbeiy Scheme 11 991 cm-' which is very similar to that obtained for Mn(tpp)O where the dioxygen is known to exhibit side-on co-ordination.Manganese(rv) is not a notably stable oxidation state and yet from an aqueous alkaline melange of the cyclic amine 1,4,7-triazacyclononane,manganese chloride oxygen and sodium bromide crystals of a stabie MnIV bridged cluster (41),were obtained. The complex is formulated [(tria~)~Mn~O~]~+ and is based on an adaman-tane-like cage with near octahedral co-ordination about each metal from three bridging oxygen ligands and one triazacyclononane ligand. It is stable in both neutral \I/ 0-Mn" /\ 19' and alkaline solutions. Not surprisingly the most interesting metal-metal bond items come from the chemistry of rhenium. Reaction between Re2CI,(PBu;) and Ph2P-py in methanol gavel9* red-purple crystals of composition Re2Cl3(Ph2Ppy),.However the structure is more complicated than this since o-metallation of one of the phenyl rings has occurred. This is shown in (42)as a view along the Re-Re axis with two axit1 chlorines omitted from the diagram for clarity. The Re-Re triple bond is 2.336A and the axial chlorines deviate from Re-Re-Cl linearity by 13-18". I97 K. Wieghardt U. Bossek and W. Gebert Angew. Chem. Int. Ed. Engl. 1983 22 328. I98 T. J. Barder S. M. Tetrick R. A. Walton F. A. Cotton and G. L. Powell J. Am. Chem. Soc. 1983 105 4090. Ti,Zr Hf;V Nb Ta;Cr Mo W;Mn Tc Re 207 A series of di-rhenium complexes Re2C1,(PR,) (n + rn = 8)' with bond orders of 3 3.5 and 4.0 has been prepared.'99 No direct response could be found for the Re-Re bond length from these changes in bond order.0rganometallics.-Ultrasonic irradiation of liquids produces acoustic cavitation and the rapid growth and decay of these short-lived vacuoles generates local 'hot-spots' of both temperature and pressure.2w With M2(CO),o (M = Mn or Re) ultrasound ('sonochemistry') promotes ligand substitution by phosphines or phos- phites.201 The reaction rate was found to be roughly first-order in metal carbonyl but independent of the concentration or the nature of the ligand. The decacarbonyls Mn2(CO),o and Re2(CO)lo are known not to 'scramble' (e.g. by refluxing in decalin) and even isotopic scrambling for the rhenium takes place only in the absence of carbon monoxide. Thus reversible homolytic fission is not exactly fashionable in this area of chemistry.For Mn2(C0)8L2 {L = PPh or P(cyc1o- hexyl),} the formation of ClMn(CO),L by reaction with C1,CH.CHC12 is shown202 to follow a mechanism that relies upon initial homolysis of the Mn-Mn bond. Apart from the obvious mechanistic checks verification for this path was obtained by observing the formation of scrambled Mn( CO),( PPh,).Mn( CO),.P(cyc) during a reaction involving both complexes simultaneously. U.V.photolysis of HMn(CO)S in an isolated matrix is known to promote the loss of one carbonyl ligand. A combination of 13C0 enrichment and i.r. spectroscopy has been usedZo3 to show that the product HMn(CO), has the C (square-pyramidal with an apical carbonyl) structure rather than the earlier C, suggestion.The C, variant (where the hydride takes the apical position) can be produced by photolysis at lower energies (A = 403 nm for Ar matrix). The compound Mn2(CO),(Ph2P-CH2-PPh2)2(p-H)(p-Br) can be decarbony-lated204 by treatment with lithium aluminium hydride to give a bridged dihydride (Scheme 12). This species has been assigned a Mn=Mn on the basis of spectroscopic and crystallographic evidence as well as by the requirements of the 18e rule. It has been shown to undergo a number of interesting substitution reactions. A thiazylfluoro complex of rhenium can be producedZo5 by reacting NSF with [Re(CO),(SO,>]+ to give [Re(CO),NSF]+. This cation is quite stable in a solution of liquid SO2 and can be usedzo6 to form thiazylamides by the addition of Me,SiNMe,.[(OC),ReNSF]+ + Me,Si.NMe + [(OC),Re(NSNMe,)]+ + Me,SiF The rhenium has been shown to be octahedral with a Re-N single bond of 216 pm and the angle Re-N-S of 130". Mn" aryl species tend to be somewhat unstable and the homoleptic Mn3(mesityl) proved too sensitive to allow microanalytical determinati~n.~'~ It was produced by I99 F. A. Cotton K. R. Dunbar L. R. Falvello M. Tomas and R. A. Walton J. Am. Chem. Soc. 1983 105 4950. 200 K. S. Suslick J. W. Goodale P. F. Schubert and H. H. Wang J. Am Chem. SOC.,1983,105 5781. 20 I K. S. Suslick and P. F. Schubert J. Am. Chem. SOC.,1983 105 6042. 202 A. Po2 and C. Sekhar J. Chem SOC.,Chem. Commun. 1983 566. 203 S. P. Church M. Poliakoff J. A. Tirnney and J. J. Turner Znorg.Chem. 1983 22 3259. 204 H. C. Aspinall and A. J. Deeming J. Chem. SOC.,Chem. Commun. 1983 838. '05 R. Mews and C.4. Liu Angew. Chem. Int. Ed. Engl. 1983 22 162. G. Hartmann R. Mews and G. M. Sheldrick Angew. Chem. Znf. Ed. Engl 1983 22 723. 207 S. Gambarotta C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. SOC.,Chem. Commun. 1983 1128. J. E. Newbery li Reagents i LiAIH,; ii CO; iii P(OMe),; iv MeNC Scheme 12 reacting MnCl with the appropriate Grignard reagent and has been formulated on the basis of X-ray crystallographic evidence. It has a linear-chain metallic core (angle Mn-Mn-Mn of 178.8') with each pair bridged by two mesityl groups. The remaining two groups are axial. The central metal is in a roughly tetrahedral site whilst the terminal metals are trigonal.Mn" is also tetrahedra1208 in Mn(CH2CMe,Ph)(PMe3), which was formed by the cleavage reaction Mn,R,(PMe,) + 2PMe * 2MnR,(PMe,) A tetrahedral benzyl species of presumably similar structure was formed when MnCl, diphosphine and Mg(CH,Ph) were reacted. (The diphosphine was used to counteract the tendency for PMe to be lost from the complex.) If the Grignard o-C6H4(CH2MgC1) was substituted for Mg(CH,Ph), however a six-co-ordinate product Mn(~-(CH,)~C~H,)(diphos)~ was formed. This is presumably a result of the ortho-ligand requiring less space at the metal and thus allowing a secondediphosphine to co-ordinate. Despite this the Mn-C distances are shorter (ca. 2.1 A) than those C. G. Howard G. S. Girolami G. Wilkinson M.Thornton-Pett and M. B. Hursthouse J. Chem. SOC. Dalton Trans. 1983 263 1. Ti,Zr Hf;V Nb Ta; Cr Mo W;Mn Tc Re of the tetrahedral complex (ca. 2.15 A) while the Mn-P distances are as much as 0.4 A shorter. The addition of methyl-lithium to a diethyl ether mixture of Me2PC2H4PMe2 and Mn"'( a~etylacetonate)~ gave a clear yellow solution.209 After extraction with petroleum spirit crystals can be obtained of both MnMe,(diphos) and MnMe,( diphos) ; it thus suggested that a disproportionation reaction (2Mn"' + Mn" + MnIV) has occurred. The magnetic moment (3.87 pB)of the former complex product is consistent with that expected for d3 MnIV. X-Ray diffraction data show an octahedral structure for the MnIV complex with the Mn-C bonds trans to !he phosphorus slightly shorter (2.06 and 2.09 A) than those alkyls mutually cis (2.12 A)..I Mn-Mn-Mn (43) The complex Mn (3-MeC5H,) was isolated2" from the reaction between MnCl and the 3-methylpentadienyl anion. Both X-ray structural analysis and variable- temperature magnetic susceptibility support a formulation as a high-spin complex. There is a near (177.5") linear trimetallic arrangement (43). Each ligand has one end co-ordinated to the central metal and this causes a near staggered configuration to be adopted about the terminal metals (with an inter-Iigand rotation angle of 35.4"). ZOY C. G. Howard G. S. Girolami G. Wilkinson M. Thornton-Pett and M. B. Hursthouse J. Chem. Soc. Chern. Commun. 1983 1 163. M. C. Bohm R. D. Ernst R.Gleiter and D. R. Wilson Znorg. Chem. 1983 22 3815.

ISSN:0260-1818    

DOI:10.1039/IC9838000171

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

9 Fe,Co Ni By B. W. FllZSlMMONS Department of Chemistry Birkbeck College Malet Street London WClE 7HX 1 Iron Iron Oxides and Compounds Containing Iron-Oxygen Bonds.-The kinetics of the dissolution of Fe304 in the presence of oxalate have been investigated and a heterogenous electron transfer process detected. The double function of the oxalate as complexing and electron-transfer reagent is stressed.' The kinetic isotope effect has been recorded in the oxidation reactions of [Fe(H20)6]2+ [Fe(D20)6I2+ and [Fe('80H2)6]2t by the oxidants [M"' bipy,] (M = Fe Ru or Cr; bipy = bipyridyl). The rate ratios are compared using current quantum theories of isotope effects and the results give support to these theories2 The formation constants of mononuclear and polynuclear hydroxy complexes of metal cations throughout the periodic table have been critically e~amined.~ It is twenty-five years since the 57Fe Mossbauer resonance was first observed spectra of aqueous solutions of iron(I1) and iron(rI1) salts have been reported for the first time.The quadrupole splitting and isomer shift recorded for solutions of iron(I1) sulphate in glass pores are the same as those of solid FeS04-7H20 thus providing the hitherto elusive proof that the aqua complex in solution is the he~ahydrate.~ The structure and stabilities of hydroxy and aquo species of the type [FeOH( H20)J+ [Fe(OH),] etc. have been analysed using electron-delocalization MO theory with the aim of determining a mechanism of anodic iron di~solution.~ The transformation y-FeOOH to stoicheiometric magnetite Fe304 in the pH range 5-9 has been investigated.6 Stoicheiometric zinc-bearing ferrites Zn Fe3-.x 04,have been pre- pared and characterized.' Magnetic exchange-interactions in the orthorhombic perovskite solid solutions Eu,-,Cr,03 0 < x < 1 are sensitive to the substituent atoms.8 In a related study 'I9Sn Mossbauer spectroscopy provides an additional probe in a range of perovskites (&,95C~.05)(Feo.8sMo.olSno.05)03 with A = La Eu or Lu and M = Al Ga Sc Cr Mn Co; or Ni.The supertransferred hyperfine field is seen to be strongly dependent upon the rare-earth metal.' The complex tri-phasic ' E. Baumgartner M. A Blesa H. A. Marinovich and A. J. G. Maroto Inorg. Chem. 1983 22 2224. T. Guarr E. Buhks and G.McLendon J. Am. Chem. Soc. 1983 105 3763. D. W. Barnum Inorg. Chem. 1983 22 2297. K. Burger and A. Virtes Nature 1983 306,353; K. Burger A. Vkrtes and I. Zay Inorg. Chim. Acta 1983 76 L247. A. B. Anderson and N. C. Debnath J. Am. Chem. Soc. 1983 105 18. Y. Tamaura K. Ito and T. Katsura J. Chem. SOC.,Dalton Trans. 1983 189. ' K. Ito Y. Tamaura and T. Katsura J. Chem. SOC.,Dalton Trans. 1983 987. T. C. Gibb J. Chem. Soc. Dalton Trans. 1983 2031. T. C. Gibb J. Chem. Soc. Dalton Trans. 1983 2035. 211 B. W.Fitzsimmons material FePO, has been the subject of a study using Mossbauer spectroscopy neutron diffraction magnetic susceptibility and electron microscopy. lo Polarized electronic spectra of vivianite Fe (PO4),-8H,O have been recorded at different temperatures in a search for spin-forbidden transitions.The spectral region 18 000 to 28 000 cm-' is dominated by bands attributed to transitions from ferromag- netically coupled iron( 11) pairs.' ' The vapours generated by heating various mixtures in the Fe2O3-HC1-H20-FeCl3 system have been investigated with the help of mass spectroscopy. The behaviour observed in the temperature range 140-350 may be explained by assuming that the molecule [H,O.FeCl,] is present.' Its standard enthalpy of formation at 500K is -589.38 kJmol-' and the standard entropy is 472.34 J mol-' K-'. By measuring the vapour-pressure concentrations of Fe,Cl,(g) above solid mixtures of Fe203 and FeCl, the enthalpy and entropy of formation of iron oxy-chloride FeOCI were ca1c~lated.l~ By recording EXAFS spectra for a range of known oxy-bridged dinuclear iron(rI1) complexes it has proved possible to show that the spectra were sensitive to both the Fe-0-Fe angle and the Fe-Fe distance thus providing a technique for estimating these parameters with useful ac~uracy.'~ A further example of a salt containing the p-0x0 anion [(FeCl3),0I2- has been isolated and characterized.This one is linear and diamagnetic." The trinuclear basic iron(Ir1) carboxylates continue to receive attention. It is now shown that inter-cluster interactions have little influence upon the magnetic susceptibility.'6 Solution equilibria of the complexes p-oxobisFe"'salen and Fe(salen)(cate-cholato) {salen = N,N'-ethylenebis( salicylideneiminato)} have been investigated.l7 A reduced Schiff-base ligand (1) forms a hydroxy-bridged iron(II1) dimer [Fe(OH),LFe]2H2O.2Py. The structure of this intramolecular anti-ferromagnet (J = -104cm-' S = 5/2) has been determined" and a dialkoxy-bridged com-plex [{Fe( salen-H)Cl},] has been characterized and its antiferromagnetic nature established. l9 The molecular structure of the piperidinium salt of the p-0x0 anion bis p-l,l'-biphenyl-2,2'-diolato-0,0')-(1,1'-biphenyl-2,2'-diolato-O,0')-ferrate( 111).ethanol0.5 a weakly coupled intramolecular anti-ferromagnet (-J = 14cm-') has been determined and is depicted in (2).,* lo G. J. Long A. K. Cheetham and P. Battle Inorg. Chem. 1983 22 3012. I' H. C. Gudel Inorg. Chem. 1983 22 3812. I* N. W. Gregory Inorg. Chem.1983 22 3750. l3 N. W. Gregory Inorg. Chem. 1983 22 2677. l4 M. S. Co W. A. Hendrickson K. 0. Hodgson and S. Doniach J. Am. Chem. SOC.,1983 105 1144. '' H. Schrnidbauer C. E. Zybill and D. Neugebauer Angew. Chem. Znt. Ed. Engl 1983 22 156. 16 B. S. Tsukerblat M. I. Belinskii and B. Ya. Kuyavskaya Inorg. Chem. 1983 22 995. " F. LLoret J. Moratal and J. Faus J. Chem. SOC.,Dalton Trans. 1983 1749. I8 L. Borer L. Thalken C. Ceccarelli M. Glick J. H. Zhang and W. M. Reiff Inorg. Chem. 1983,22 1719. 19 L. Borer L. Thalken J. H. Zhang and W. M. Reiff Inorg. Chem. 1983 22 3174. *' E. W. Ainscough A. M. Brodie S. J. McLachIan and K. L. Brown J. Chem. SOC.,Dalton Trans. 1983 1385. Fe Co Ni 213 (2) The p-0x0 Schiff-base complex [FeL(OH)C1]2.C4H80 (L3- is the anion of trisalicylidenetriethylenetetramine),illustrated schematically in (3) is a weak antifer- romagnet” with -J = 8 cm-’.p-0x0 acetatobis(tri- 1-pyrazolborato)di-iron(111) has been structurally established using X-ray methods and is suggested as a model for the dinuclear centre of haemerythrin.” EXAFS studies of the dinuclear iron centre in deoxyhaemerythrin give results consistent with a model in which the p-0x0 B. Chiari 0.Piovesana T. Tarantelli and P. F. Zanazzi Inorg. Chern 1983 22 2781. W. H. Armstrong and S. J. Lippard J. Am. Chern. Soc. 1983 105 4837. B. W. Fitzsimmons bridge is replaced by two hydroxy-groups one of them bridging; the other ligands remaining in position as illustrated schematically in (4).23 The nature of the iron His His I ,His ,O-Fe-0, 1 Asp-< OH /C-Glu '0-Fe -0' His' I 'His His (4) Asp = aspartic acid; Glu = glutamic acid; His = histidine centre in porcine allantoic purple acid phosphatase has been inferred by direct comparison of its magnetic behaviour with that of a synthetic Iron(Ir1) acetylacetonate may conveniently be prepared by heating the diketone with freshly precipitated ferric oxide.25 The 57Fe and '"Eu Mossbauer spectra of the perovskites EuFe,-,Co,03 have been recorded and the substitutional effects analysed.26 The equilibria and kinetics of reaction between Fe"' Co" Ni" Cu" and l,l,l,-trifluoropentane-2,4-dione have been investigated and the enol form of the diketone identified as the active specie^.^' An 'H n.m.r.study of the aqueous solution reaction between the phosphate ligand (5) and the ions Mn" Fe"' Co" Ni" Cu" and Zn" reveals a greater degree of aquation than with the corresponding carboxylate com- plexes.28 A series of iron( 111) complexes containing chelating phosphine oxides L-L[L-L = e.g. Ph2P( =O)(CH,),P( =O)Ph2] have been prepared and characterized. -0 0-(5) (6) These include complexes of formula [Fe( L-L),C1,][FeCl4] [FeL-L(ON02),] et~.,~ The stability constant of N,N'-ethylenebis( salicylideneminato)iron( 111) in dimethyl- sulphoxide solution has been e~timated.~' Reactions between iron( 111) Schiff base complexes of N,N'( 1,2-diaminobenzene)bis( salicylideneiminato) and several ortho-and para-quinones have been isolated and characteri~ed.~' The crystal and molecular structure of three complexes of [Fe"'(salen)]+ have been determined.These are [Fe(salen)acac] [Fe(salen)psq] and K[Fe(salen)cat] (catHz = catechol psq = phenanthrenesemiquinone). The co-ordination spheres are octahedral [FeN2O4] 23 W. T. Elarn E. A. Stern J. D. McCallum and J. Sanders-Loehr J. Am. Chem. SOC. 1983 105 1919. 24 G. M. Mockler J. de Jersey B. Zerner C. J. O'Connor and E. Sinn J. Am. Chem. SOC.,1983,105 1891. 25 M. K. Chaudhuri and S. K. Ghosh J. Chem. SOC.,Dalton Trans. 1983 839. 26 T. C. Gibb J. Chem. SOC.,Dalton Trans. 1983 873. 27 M. J. Hynes and M. T. O'Shea J. Chem. SOC.,Dalton Trans. 1983 331. 28 J. Oakes and E. G. Smith J. Chem. SOC.,Daiton Trans. 1983 601. 29 T. S. Lobana H. S. Cheema and S.S. Sandhu J. Chem. SOC.,Dalton Trans. 1983 2039. 30 F. LLoret J. Moratal and J. Faus J. Chem SOC.,Dalton Trans. 1983 1743. 3' J. P. M. Tuchagues and D. N. Hendrickson Inorg. Chem. 1983,22 2545. Fe Co Ni 215 in each case.32 The synthesis of a new multidentate ligand (6) has been described and its complexation with Fe" Fe"' Co*I Ni" Cu'I and Zn" investigated using potentiometric methods. Iron( 111) pox0 compounds were detected.33 Iron( 111) N,N'-ethylenebis( 0-hydroxyphenyl)glycinate and octahedral [FeN20,] complex has been evaluated spectroscopically as a model for the binding site in tran~ferrins.~~ An iron(1rr) complex of muginec acid has been prepared and is shown to be a typical high-spin iron( 111) complex. The molecular structure of the Co"' analogue has been determined.35 Iron( 111) complexes [Fe(ent)] or [Fe(MECAM)] (7) and (8), qoH OH c=o I I \ o=c HFH \ OH (7) (JoH 'OH I c=o I NH I (8) have been shown36 by Mossbauer spectroscopy carried out on frozen aqueous solutions to remain as iron(rr1) species over the pH range 2-10 but redox processes 32 R.B. Lauffer R. H. Heistand and L.Que Inorg. Chem 1983 22 50. 33 C. Y. Ng A. E. Martell and R. J. Motekaitis Inorg. Chem. 1983 22 721. 34 M. G. Patch K. P. Simolo and C. J. Carrano Inorg. Chem 1983 22 2360. 3s Y. Mino T. Ishida N. Ota M. Inoue K. Nomoto T. Takemoto H. Tanaka and Y. Sugiura 1 Am Chem SOC.,1983 105,4671. 36 V. L. Pecoraro G. B. Wong T. A. Kent and K. N. Raymond J.Am. Chem. SOC.,1983 105 4617. 216 B. W. Fitzsimmons take place in methanol at low pH. A solid-state i.r. study of iron( 111) catechoylamide complexes indicates that the salicylate bonding mode operates.37 Two iron( 111) hydroximate siderophores coprogen and ferricrocin have been extracted from natural sources and characterized. Their formation constants and redox potentials were recorded.38 Kinetic Studies on Iron Complexes.-Table 1 shows recent papers.3948 Table 1 Complex of species Reagent Re$ [Fe phenJ2+ c102-39 [Fe"'EDTA] [RU(NH3)612+ 40 w2o)i3-N-Bases 41 CF~(CN), Fe3+ [FeI"6 DT A] isopropyltropolone 42 02-43 [Fe(CN) baseI3- light 44 [Fe en(CN),]'- electron transfer 45 [Fe"'DMSO,] exchange 46 Fe"' Fe"' exchange 47 Fe3+,q CNS-48 phen = 1,lO phenanthroline EDTA = ethylenediaminetetra-acetate en = 1,2-diaminoethane DMSO = dimethylsulphoxide Compounds Containing Nitrogen-Donor Ligands.-The complex [Fe(4-~c~~)~(H,O),(NCS),], (4-acpy = 4-acetyl pyridine) contains a trans-Fe[N,OJ centre.The level scheme is xz,yz <xy in consonance with a relatively modest Mossbauer quadrupole splitting of 1.7-1.9 mm s-' and there is no magnetic hyper- fine splitting in the 4.2 K A series of synthetic non-porphyrin reversible dioxygen carriers (9) has been synthesized and tested.50i51 The interaction of some iron(r1) complexes of the type (10) with nitrogen bases CO and O2has been studied and in the latter case a two-electron redox process has been un~overed.'~ The base-catalysed reduction of [Fe(bipy)J3+ yields a variety of products it has been 37 V.L. Pecoraro W. R. Harris G. B. Wong C. J. Carrano and K. N. Raymond J. Am. Chem. SOC.,1983 105 4623. 38 G. B. Wong M. J. Kappel K. N. Raymond B. Matzanke and G. Winkelmann J. Am. Chem. SOC. 1983 105 810. 39 L. A. Lednicky and D. M. Stanbury J. Am. Chem. SOC.,1983 105 3098. 40 F. Moattar J. R. Walton and L. E. Bennett Inorg. Chem. 1983 550. 41 A. L. Coelho H. E. Toma and J. M. Malin Inorg. Chem. 1983 22 2703. 42 K. Ishihara S. Funahashi and M. Tanaka Inorg. Chem. 1983 22 194. 43 C. Bull C. J. McClune and J. A. Fee J. Am. Chem. SOC.,1983 105 5290. 44 K. J. Moore L. Lee J. E. Figard J. A. Gelroth A. J. Stinson H. D. Wohlers and J. D. Petersen J.Am. Chem. Soc. 1983 105 2274. 45 A. M. de C. Ferreira and H. E. Toma J. Chem. SOC.,Dalton Trans. 1983 2051. 46 C. H. McAteer and P. Moore J. Chem. Soc. Dalton Trans. 1983 353. 47 J. J. Hupp and M. J. Weaver Inorg. Chem. 1983 22 2557. 48 S. Funahashi K. Ishihara and M. Tanaka Inorg. Chem. 1983 22 2070. 49 G. J. Long G. Galleazzi U. Rosso G. Valle and S. Calogero Inorg. Chem. 1983 22 507. 50 N. Herron J. H. Cameron G. L. Neer and D. H. Busch J. Am. Chem. Soc. 1983 105 298. 5' N. Herron L. L. Zimmer J. J. Gnybowski D. J. Olszanski S. C. Jackels R. W. Callahan J. H. Cameron G. G. Christoph and D. H. Busch J. Am. Chem. SOC.,1983 105,6585. 52 N. Herron W. P. Schammel S. C. Jackels J. J. Grzybowski L. L. Zimmer and D. H. Busch Inorg. Chem. 1983 22 1433.Fe Co Ni 217 RZ R2 1 B = I-methylimidazole R' = m-xylylene R2= R3 = Me R2=benzyl; R3 = Me 1 Rf = Me;R3 = Ph (9) Rz= benzyl; R3 = Ph studied with a view to establishing rates and st~icheiometry.~~ The electronic infrared Raman and resonance Raman spectra of a number of iron(r1) di-imime complexes have been recorded and analysed. These include [Fe(phen),(CN)J and [Febipy,]( BFJ2 (phen = 1,lo-phenanthroline bipy = 2,2'-bipyridyl) in which the resonance enhancement originates in charge-transfer transition^.^^ Complex formation between iron( 111) and some di-imine polymers has been in~estigated.~'The electronic structures of the bipyridyl complexes [Mbipy J3+ (M = Fe Ru or 0s) have been elucidated with the help of appropriate theoretical models and e.p.r.spectro~copy.~~ Electrochemically generated reduction-products of [ML3I2+ (M = Fe" or Ru" L = 2,2'-bipyridyl) have been identified using variable-temperature e.~.r.~~ A laser-Raman spectral study of iron(r1) complexes of the di-imines (1 1) and (12) has been carried out. The complex [FeL,]*+(PF,), where L = (1 l) hitherto believed to be exclusively high-spin is shown to contain a fraction of the low-spin isomer.58 Spin-Crossover among Fe" Compounds.-This continues to be an active area of research and some progress has been made this year. Methods include variable- temperature magnetic susceptibility Mossbauer and vibrational spectroscopy some groups obtain X-ray diffraction information on both sides of phase boundaries.A linear trinuclear complex of 4-ethyl triazole [Fe (Tr)6(H20)6](CF3S03)6 shows a first-order transition at 203 K and its structure has been solved above and below 53 G. Nord B. Pedersen and E. Bjergbakke J. Am. Chem. SOC.,1983 105 1913. 54 L. Griffiths B. P. Straughan and D. J. Gardiner J. Chem. SOC.,Dalton Trans. 1983 305. 55 J. D. Miller and D. S. Morton J. Chem Soc. Dalton Trans. 1983 151 1. 56 E. M. Kober and T. J. Meyer lnorg. Chem. 1983 22 1614. 57 D. E. Morris K. W.Hanck and M. K. DeArmond J. Am. Chem. SOC.,1983 105 3032. 58 W. H. Batschelet and N. J. Rose lnorg. Chem. 1983 22 2078. B. W. Fitzsimmons this temperature to reveal significant differences in the Fe-N bond lengths.59 A detailed study of the iron(rr) complex [FeL2(NCS)2] where L = (13) reveals a Mexs,H:jMe NN (13) transition temperature of 219.5 K.These authors develop different models for the two main types of spin-crossover sharp or gradual opting for a solid-solution model for the second type.60 The solid-solution model is again taken up in a paper from the same laboratory describing a gradual crossover system.61 The complex [FeL6]- (BF,) (L = n-propyl tetrazole) shows a sharp transition whereas its homologues exhibit the gradual behaviour.62 Variable-temperature Raman spectroscopy has been deployed in an investigation of the spin-crossover complex [FeL]( PF6)2 where L = (11):~ Variable-pressure experiments as applied to spin-crossover systems can be con- veniently monitored using Mossbauer spectroscopy and this year sees the reinvestiga- tion of the classic case [Fe phen,X2J (X = NCSe NCS or N3) over the pressure range 0.001 to 45 kbar at ambient temperature.Sharp5T-'A transitions (Figure I) are observed in a narrow pressure range for the first two compounds with none of the bizzare irregularities earlier reported. The azido compound is more difficult to 'HS t P/k bar 10 20 30 40 50 Figure 1 Area fraction X, of the iron(1r) high-spin doublet from the Mossbauer spectra of Fe(phen)2(X) with X = NCS- NCSe- and N3-as a function of high pressures up to 45 kbar 59 G.Vos R. A. IeF'bbre R. A. G. de Graff J. G. Haasnoot and J. Reedijk J. Am. Chem. Soc. 1983 105 1682. E. Konig G. Ritter S. K. Kulshreshtha and S. M. Nelson 1.Am.Chem. SOC.,1983 105 1924. 61 E. Konig G. Ritter S. K. Kulshreshtha and H. A. Goodwin Znorg. Chern 1983 2518. 62 E. W. Miiller J. Ensling H. Spiering and P. Gutlich Inorg. Chem. 1983 22 2074. 63 W. H. Batschelet and N. J. Rose Inorg. Chem. 1983 22 2083. Fe Co Ni 219 convert; it remains a 3 1 mixture at the high-pressure limit.64 A further instance of rapid electronic relaxation in a 6A-2T crossover system has been un~overed.~~ Porphyrinato-iron Compounds.-'H n.m.r. evidence has been adduced in the question of the presence or otherwise of the ferryl group (Fe=O) in ferryl myoglobin and in compound (11) of horseradish peroxidase by comparison of their spectra with those of model compounds.66 Workers in the same laboratory have been successful in incorporating modified haems into horseradish peroxidase and have used n.m.r.spectroscopy to determine the orientation of the haem in its pocket. They consider that their method might be generally appli~able.~~ Evidence for structural changes occurring in the haem environment due to the NO group has been obtained from 14 N and 'HENDOR spectra of nitrosyl derivatives of human haemoglobin and its separate a and p sub-units myoglobin and related nitrosyls.68 Reactions of rel- evence to the disablement of haemoglobin or myoglobin by phenylhydrazine has been looked into by two groups a-bonded iron complexes are implicated. The first of these studies employed the chloro complex [ClFe"'TPP] (TPP here and later is tetraphenyl porphinato) as the model.Both diazine complexes (14) and a-complexes R NH N (14) were The second study deploys natural haems as substrates and n.m.r. as probe for the a-c~rnplexes.~~ The preparation of a new kind of porphyrin-like synthetic macrocycle tetrakis(3,5- di-t-butyl-4-hydroxyphenyl)porphine, has been carried out and the its iron and zinc salts i~olated.~' Mixed-metal face-to-face porphyrin dimers as depicted in (15) have been ~ynthesized.~~ Using the synthetic picket-fence porphyrin models the effect of differing axial bases on O2or CO affinities have been worked As an extension of work on synthetic haem models 'pocket' porphyrins (16) have been prepared and ~haracterized.~~ They form stable and reversible dioxygen complexes. In a further paper kinetic and equilibrium studies of the O2 and CO complexes are 64 J.Pebler Inorg. Chem. 1983 22 4125. 65 H. Ohshio Y. Maeda and Y. Takashima Znorg. Chem. 1983 2684. 66 G. N. La Mar J. S. de Ropp L. Latos-Grazynski A. L. Balch R. B. Johnson K. M. Smith D. W. Parish and R.-J.Cheng J. Am. Chem. SOC.,1983 105 782. 67 G. N. La Mar J. S. de Ropp K. M. Smith and K. C. Langry J. Am. Chem. SOC.,1983 105 4576. 68 M. Hohn J. Hiittermann J. C. W. Chien and L. C. Dickinson J. Am. Chem. Soc. 1983 105 109. 69 P. Battioni J. P. Mahy G. Gillet and D. Mansuy J. Am. Chem. SOC.,1983 105 1399. 70 K. L. Kunze and P. R.Ortiz de Montcllano J. Am. Chem. SOC.,1983 105 1380. 7' T. G. Traylor K. B. Nolan and R. Hildrith J. Am. Chem. SOC.,1983 105 6149.72 J. P.Collman C. S. Bencosme R. R. Durand R.D. Kreh and F. C. Anson J. Am. Chem. SOC.,1983 105 2699. 73 J. P. Collman J. 1. Brauman K. M. Doxsee J. L. Sessler R. M. Moms and Q. H. Gibson Znorg. Chem. 1983 22 1427. 74 J. P. Collman J. I. Brauman T. J. Collins B. L. Iverson G. Lang R. B. Pettman J. L. Slesser and M. A. Walters J. Am. Chem. SOC.,1983 105 3038. B. W.Fitzsimmons -H H- (15) M = Fe M'= Co (16) M = Fe described the factors enhancing O2 affinity over that for CO being further el~cidated.~~ The molecular structure of an iron-chlorin has been established using X-ray methods. The chlorin is Fe(OEC) OEC = trans-7,8-dihydro-2,3,7,8,12,13,17,18-octaethyl porphyrinato diani~n.'~ Like Fe"TPP this compound has S = 1.A low-temperature( 100 K) X-ray diffraction study has been carried out on the methoxy compound [MeOFe(TPP)] and the electron-density difference maps con- structed. The electron distribution at the iron is seen to be spherical in agreement with high-spin iron( III).~~ The trans-difluoro anion [F,Fe(TPP)]- prepared by HF cleavage of the p-0x0dimer is a high-spin porphyrinate with an unusually expanded iron core and a hydrogen-bonded distal imida~ole.'~ Low-spin six-co-ordinate [FeTPP(CN)Py] has been synthesized and its structure together with that of a manganese analogue established by X-ray method^.'^ A monoclinic form of bis(3- chloropyridine)(octaethylporphinato)iron(Ir) perchlorate has been prepared its molecular structure solved by X-ray methods and otherwise physically characterized.Previously reported as a singlet-triplet spin-equilibrium it now emerges that it is the triclinic modification which is a spin-equilibrium but this phase with peff= 4.7 BM at 295 K is a quantum-mixed intermediate-spin state.80 Thin-layer spec- troelectrochemical techniques have been deployed in an investigation of the Fe"/ Fe"' couple in [Fe"'TPP]+X- as a function of counterion.81 Hydrogen-bonding from imidazole has been shown markedly to affect the redox potential of iron-porphyrin complexes the iron( 111) state being significantly stabil- ized.82A study in which electronic spectroscopy and electrochemical techniques are combined is that of the electron-transfer reactions of the complexes [Fe( NO)TPP] or [Fe"(NO)OEP] it has led to the elucidation of a variety of processes including 75 J.P. Collman J. I. Brauman B. L. Iverson J. L. Sessler R. M. Morris and Q. H. Gibson J. Am. Chem. Soc. 1983 105 3052. 76 S. H. Straws M. E. Silver and J. A. Ibers J. Am. Chem. SOC.,1983 105 4108. 77 C. Lecompte D. L. Chadwick P. Coppens and E. D. Stevens Inorg. Chem. 1983 22 2982. 78 W. R. Schiedt Y. J. Lee S. Tamai and K. Hatano J. Am. Chem. SOC., 1983 105 778. 79 W. R. Schiedt Y. J. Lee W. Luangdilok K. J. Haller K. Anzai and K. Hatano Inorg. Chem. 1983 22 1516. 80 W. R. Schiedt D. K. Geiger R. G. Hayes and G. Lang J. Am. Chem. Soc. 1983 105 2625. 81 K. M. Kadish and R. K. Rhodes Znorg. Chem. 1983 22 1090. 82 M. M. C. Doeff D. A. Sweigart and P.O'Brien Inorg. Chem. 1983 22 851. Fe Co Ni 22 1 the formation of bis-nitrosyl complexes and the co-ordination of solvent m01ecules.~~ The injection of two electrons into porphyrinatoiron carbene complexes is a carbene- centred reaction. Thus the dichlorocarbene derivative [TPPFe :CCl,] is smoothly converted into the p-carbido dimer [TPPFe2C].84 The same group of workerss4 have prepared a wide range of nitrosoalkane complexes [( RNO)FeTPP] some having axially co-ordinated .axial base. The molecular structure of one example [(i- C3H7NH2)Fe(TPP)(i-C3H7N0)],established using X-ray methods reveals N-bonding of the RNO ligand and consideration of physical properties reveals a strong similarity between RNO and O2 as ligands to iron.s5 A photogalvanic cell has been constructed in which the illuminated electrode is coated with [ClFe"'TPP(irnidaz~le)]~ and voltages generated by photodissociation of C0.86 Iron(rr )tetrakis ( N-methyl-4-pyridy1)porphyrinhas been shown to convert O2 into H20 in a multistage The effect of the spin-equilibrium in electron-transfer rate-constants in a series of bis-axial ligand octaethyl-porphyrin complexes has been shown to play little role in the processes.88 Porphyrin complexes in the presence of iodosylbenzene a source of oxygen atoms catalyse the hydroxylation of unactivated alkanes.89 This same system brings about the epoxidation of alkenes e.g.cyclohexene -* cyclohexene oxide (93%).90 Chiral iron porphyrins have been successfully employed in reaction with prochiral alkenes to yield chiral epoxides?' Introduction of bulky substituents (t-BuCONH) into the ortho position of TPP ligands leads to isomerism.By recording the * H n.m.r. spectra of the different low-spin bis-ligand complexes it proved possible to assign the pyrrole resonances and to sort out the preferred site for electron delo~alization.~~ Using 13C-enriched CO the mechanisms of spin-lattice relaxation have been established in particular the effect of tr~ns-ligation.~~ Work has con- tinued on the TPP complexes in which the iron atom carries an inserted ligand. The complexes (17) and (18) have been examined with the aid of resonance Raman Ar ,Ar C II 83 D. Lancon and K. M. Kadish J. Am. Chem. Soc. 1983 105 5610. 84 J.-P. Battioni D.Lexa D. Mansuy and J.-M. Saveant J. Am. Chem. Soc. 1983 105 207. D. Mansuy P. Battioni J.-C. Chottard C. Riche and A. Chiaroni 1.Am. Chem. Soc. 1983 105 455. 86 B. M. Hoffman and P. D. Sima J. Am. Chem. SOC.,1983 105 1776. P. A. Forshey and T. Kuwana Znorg. Chem. 1983 22 699. 88 K. M. Kadish and C. H. Su J. Am. Chem. Soc. 1983 105 177. 89 J. T. Groves and T. E. Nemo J. Am. Chem. Soc. 1983 105 6243. 90 J. T. Groves and T. E. Nemo J. Am. Chem. Soc,1983 105 5786. 9' J. T. Groves and R. S. Meyers J. Am. Chem. Soc. 1983 105 5791. 92 F. A. Walker J. Buehler J. T. West and J. L. Hinds J. Am. Chem. Soc. 1983 105 6923. 93 T. Perkins J. T. Saterlee and J. H. Richards J. Am. Chem. Soc. 1983 105 1350. 222 B. W. Fitzsimmons spectroscopy. There are significant differences between the spectra of these and their four-fold symmetric analogues.The differences are traced to a severe tilting of one of the pyrrole rings in the inserted corn pound^.^^ Mossbauer spectroscopy has been used in a sort-out of the different centres of oxidation in a series of p-0x0 and p-nitrido iron( rrr) complexes.95 The principal component of the electric field gradient as determined using magnetically perturbed Mossbauer spectroscopy is negative in the bis carbonyl of iron( 1I)octamethylbenzporphyrin. It is shown that successive replacement of piperidine by CO increases the negative contribution to Vzz.It is positive in the TPP analogue and negative in the five-co-ordinate monocar- bony1 TPP or OEP complexes.96 Magnetic circular dichroism has been established as a useful technique for the determination of the magnitude and sign of zero-field splitting in iron( 111) porphyrinato complexes such as [ClFe(TPP)] for which a value of 6.9 cm-' has been rep~rted.~' E.p.r.studies of a series of thiolato complexes of the type [(thiolate)FeTPP] have established a correlation between the pK of the thiolate and the tetragonality of the ligand field.98 Electron ionization mass spectra as a function of sublimation temperature between 600 and 670 K have been obtained for iron cobalt and nickel phthal~cyanins.~~ Two crystalline modifications of p-oxobisphthalocyaninatoiron(rrr) have been synthesized and characterized. These seem to be the first iron( 111) phthalocyanin compounds to be isolated it is suggested that different Fe-0-Fe bond angles are involved.loo The crystal and molecular structure of ferrous phthalocyanin has been determined at 110 K.Inspection of the electron-density difference maps has led to direct establishment of the electronic ground state lo' it is 3Eg.Enhanced Fe-02 bonding has been attributed to H-bonding to the unco-ordinated end of the O2 molecule in a model system as judged from the result of an 'H n.m.r. study."* Further Papers on the Subject of Porphinato Complexes of Iron these are listed in Table 2.'03"11 94 B. Chottard D. Mansuy and H. J. Callot Inorg. Chem. 1983 22 362. 95 D. R. English D. N. Hendrickson and K. S. Suslick Inorg. Chem. 1983 22 367. % K. J. Reimer C. A. Sibley and J. R. Sam J.Am. Chem. SOC.,1983 105 5147. 97 W. R. Browett A. F. Fucaloro T. V. Morgan and P. J. Stephens 1. Am. Chem. SOC.,1983 105 1868. 98 M. P. Byrn B. A. Katz N. L. Keder K. R. Levan C. J. Magurany K. M. Miller J. W. Pritt and C. E. Strouse J. Am. Chem. SOC.,1983 105 4916. 99 S. M. Schildercrout J. Am. Chem. SOC.,1983 105 3852. 100 C. Ercolani M. Gardini F. Monacelli G. Pennesi and G. Rossi Inorg. Chem. 1983 22 2584. 101 P. Coppens L. Li and N. J. Zhu J. Am. Chem. SOC.,1983 105 6173. I02 J. Mispelter M. Momenteau D. Lavalette and J.-M. Lhoste J. Am. Chem. SOC.,1983 105 5165. 103 J. D. Saterlee J. D. Erman G. N. La Mar K. M. Smith and K. C. Langry J. Am. Chem. SOC.,1983 105 2099. I04 J. A. Shelnutt J. Am. Chem. SOC.,1983 105 774. I05 J. A.Shelnutt Inorg. Chem. 1983 22 2535. '06 J. S. Olsen R. E. McKinnie M. P.Mims and D. K. White J. Am. Chem. Soc. 1983 105 1522. 107 G. A. Schick and D. F. Bocian J. Am. Chem. SOC 1983 105 1830. I08 P. Jones D. Mantle and I. Wilson J. Chem. SOC.,Dalton Trans. 1983 161. '09 A. Shirazi E. Leum and H. M. Goff Inorg. Chem. 1983 22 360. I10 J. M. Green and L. R. Faulkner 1.Am. Chem. Soc. 1983 105 2950. Ill L. Griffiths B. P. Straughan. and D. J. Gardiner J. Chem. SOC.,Dalton Trans 1983 1193. Fe Co Ni 223 Table 2 Subjecr Ref 'H n.m.r. spectra of cyctochrome c and azido derivatives 103 Resonance Raman spectra of metallouroporphyrins Fe"' Co" Ni" and Cull and their 1,l O-phenanthroline complexes 104 105 Kinetics and mechanism of reaction between alkyl isocyanides and 106 protohaem complexes Resonance Raman spectra of p-nitrido tetraphenylporphyrine com-plexes 107 Reaction kinetics of hydrogen peroxide-iron( 111) porphyrin reactions 108 13Cand 'H n.m.r.spectra of iron porphyrin 1,2-dimethylimidazole com- plexes 109 Redox reactions of thin films of metal (Fey Co Ni Cu or Zn) phthalocyznins 110 Resonance Raman spectra of iron( 11) phthalocyanins 111 Compounds Containing Iron-Sulphur Bonds.-Four new low-spin iron( rv) dialkyl diselenocarbamate complexes [Fe( Se2CNR2),]' have been prepared as BF4 salts and subjected to variable-temperature magnetochemistry Mossbauer spectroscopy hnd X-ray photoelectron spectroscopy. The molecular structure of the N,N-dibenzyl derivative solved by X-ray methods shows an [FeSe6] core intermediate in stereochemistry between octahedral and trigonal prism.112 A range of Fe" and Fe"' complexes of the thio-Schiff bases (19) (20) and (21) have been prepared and the CH=N CH=N NH2 \R \R! \R! molecular structure of a p-0x0 bridged dinuclear example determined by X-ray diffraction.'13 The four-co-ordinate [FeS,] salt NEt,[Fe(SPh),] has DZdsymmetry as determined using X-ray diff raction.'14 The simple monomeric tetrahedral systems [Fe(MS4)J3-(M = Mo or W) have now been satisfactorily prepared and charac- terised."' The electronic ie.and resonance Raman spectra of a series of the type (22) have been recorded and evidence found for extensive Fe-S electron (22) M = Mo or W I12 P. Deplano E. F.Trogu F. Bigoli E. Leporati M. H. Pellinghelli D. L. Perry R. L. Saxton and L. J. Wilson J. Chem. SOC.,Dalton Trans. 1983 25. 113 P. J. Marini K. S. Murray and B. 0. West J. Chem. SOC.,Dalton Trans. 1983 143. 114 S. A. Koch L. E. Maelia and M. Millar J. Am. Chem. SOC.,1983 105 5944. 115 C. D. Friesen J. W. McDonald W.E. Newton W. B. Euler and B. M. Hoffman Inorg. Chem. 1983 22 2202. 224 B. W Fitzsimmons delocalization. ' l6 The e.p.r. spectra of chemically reduced species of formula [Fe,S,(S Aryl),] have been recorded and analysed.' '' The tetrahedral [Fe"S,] complex anions [(C6H5S) FeS2MS,I2-and [(S5)FeS2MS2I2-have been synthesized and spectroscopically characterized.' '*New synthetic methods for the preparation of the dinuclear complexes [Fe S2Cl4I2-and [Fe20Cl6I2-have been developed.' l9 The complex anion [Fe(SEt),12-is a strong reducing agent and serves as a versatile precursor to a series of 2Fe 3Fe and 6Fe [Fe-S-SR] clusters.'20 A detailed study involving isotopic substitution of the resonance Raman and i.r.spectra of spinach ferredoxin adredoxin and an analogue compound has been carried out. The ends of the FezS2complex are inequivalent as a result of the neighbouring protein.'21In a similar study of rubredoxin splittings of the Fe-S modes are again detected but here attributed to coupling between Fe-S and S-C-C modes.'22 Applying the experimental method outlined above to 3Fe and 4Fe ferredoxins evidence is put forward for non-planar conformations (23) or (24) of [3Fe-3-S] structure^.'^^ s\ S S/Fe-S (23) (24) This year sees the full account of the preparation and characterization of a number of salts of a single [MoFe,S,] cubane structure similar in all respects with that thought to be present in nitrogenase.The synthesis and full structural characteriz-ation using X-ray methods ofthe [Fe Mo] cubane cluster (25) has been de~cribed.'~ 3-I \ L SAr (25) R = vinyl I I6 R. J. H. Clark T. J. Dines and G. P. Proud J. Chem. SOC.,Dalton Trans. 1983 2299. I I7 P. Beardwood and J. F. Gibson J. Chem. Soc. Dalton Trans. 1983 737. I18 D. Coucouvanis P. Stremple E. D. Simhon D. Swenson N. C. Baenziger M. Draganjac L. T. Chan A. Simopoulos V. Papaefthymiou A. Kostikas and V. Petrouleas Inorg. Chem. 1983 22 293.I19 Y. Do E. D. Simhon and R. H. Holm Inorg. Chem. 1983 22 3809. 120 K. S. Hagen A. D. Watson and R. H. Holm J. Am. Chem. Soc. 1983 105 3905. 121 V. K. Yachandra J. Hare A. Gewirth R. S. Czernuszewicz T. Kimura R. H. Holm and T. G. Spiro J. Am. Chem SOC.,1983 105 6462. V. K. Yachandra J. Hare H. I. Moura and T. G. Spiro J. Am. Chem. Soc. 1983 105 6455. I23 M. K. Johnson R. S. Czernuszewicz T. G. Spiro J. A. Fee and W. V. Sweeney J. Am. Chem. SOC. 1983 105 6671. 124 P. K. Masharak W. H. Armstrong Y. Mizobe and R. H. Holm J. Am. Chem. SOC.,1983 105,475. 12' Fe Co Ni 225 Although the M-S and Fe-S(C1) distances as determined by EXAFS agree with the crystallographic values for the anion [C12FeS2MS2FeC1J2- to better than 9% a comparison of EXAFS parameters of the dianion with those of the MoFe protein of nitrogenase reveal significant difference^.'^^ An interesting stereochemical change has been observed for an [Fe,S,] cubane.This is the anion [Fe,S,-(S-p-C,H,Br),]- which is non-tetragonal in the solid but is tetragonal in solution. A further core change is one associated with electron- transfer and seems to be a general feature of these systems.126 A neutral cubane prepared from either [Fe4(SR),I2- or [Fe4S4Cl4I2- has the structure (26).127 Trinuclear complexes [M3S(S2-~y1)3]2- (M = Fe or Co”’ S,-xyl = 0-xylene-[a,a‘]-dithiolate have been prepared and isolated as their [Et,N] salts. 0-Ph Ph/O ‘ The molecular structure of one example (27) has been determined and the isomorph- ism of the iron and cobalt derivatives established.’28 The structure of the quasi-cubane cluster [Fe,S4(SPh)2( Et,dt~)~]~- contains inequivalent pairs of four- and five-co- ordinate iron atoms.*29 The kinetics and mechanism of an homogeneous H,-evolving system [Mo Fe6S8(SPh),14-”-PhSH have been investigated and a reaction scheme put forward. 130 Compounds with Iron-Halogen Bonds.-In response to the publication of conflicting results a re-examination of the species present in aqueous solutions of iron(m) chloride has been made using X-ray methods. An earlier report of the formation of chloro-complexes has been ~onfirmed.’~’ The 57Fe Mossbauer spectra of the chloro-complexes [M’M”xFel-xC13~2H20] (M’ = K or Rb M” = Mn Co or Ni x = 0.5) have been recorded and interpreted,132 as have spectra of the compounds M,Fel-,C12~yH,0(M = Mn Co or Ni; x = 0.5 or 0.6.133 The complex [FeCl6l3- has been investigated as an impurity in an exact octahedral site using absorption and m.c.d.spectroscopy and the results fitted to a ligand-field 125 B. K. Teo M. R. Antonio D. Coucouvanis E. D. Simhon and P. P. Stremple J. Am. Chem. Soc. 1983 105 5767. 126 D. W. Stephan G. C. Papaefthymiou R. B. Frankel and R. H. Holm Inorg. Chem. 1983 22 1550. 127 W.E. Cleland D. A. Holtman M. Sabat J. A. Ibers G. C. DeFotis and B. A. Averill J. Am. Chem. SOC.,1983 105 6021. 128 KdS. Hagen G. Christou and R. H.Holm Inorg. Chem. 1983 22 309. I29 M. G. Kanatzidis M. Ryan D. Coucouvanis A. Simopoulos and A. Kostikas Inorg.Chem. 1983 22 179. 130 T. Yamamura G. Christou and R.H. Holm Inorg. Chem. 1983 22 939. 131 G. Giubileo M. Magini G. Licheri G. Paschina G. Piccaluga and G. Pinna Inorg. Chem. 1933 22 1001. ‘32 B. Y. Enwiya J. Silver and I. E. G. Morrison J. Chem. SOC.,Dalfon Trans. 1983 1039. ‘33 B Y. Enwiya J. Silver and I. E. G. Morrison J. Chem. Soc. Dalton Trans. 1983 2581. 226 B. W. Fitzsimmons m0de1.l~~ The magnetic properties of the tetragonal phase K Mn Fel- F3 have been studied over a range of comp~sition.'~~ Iron Carbonyls and Related Compounds.-Products of y-radiolysis of frozen glasses containing Fe(CO)5 or [Fe(C0)4]- have been identified using e.p.r one-electron addition dominate^.'^^ The unsaturated species [Fe(CO),]( n = 2,3 or 4) have been identified as products in the pulsed U.V.photolysis of Fe(C0)5.137 The iron carbonyls Fe2(C0)9 or Fe,(CO), interact with hydrated sodium-Y zeolite as the hydrido- species [HFe,(CO) Both unsaturated metallic molecular ions and atomic ions are formed if iron carbonyls or their substituted derivatives are subjected to U.V. and visable multiphoton processes.139 The nature of the bonding in [Fe(C0)4.CH2=CH2] has been looked into with the aid of photoelectron spectros- copy.14o Sulphinylaniline complexes e.g. [Fe( PPh3)2Me(CH20)3 P(ArNSO)] having the structures indicated in (28) have been prepared and ~haracterized.'~' Sulphur dioxide is a two-electron q'-donor in a series of five-co-ordinate compounds [FeL2(C0),S02] [L = (Ph0)3P etc.].These air-stable complexes exist in two forms trans-diaxial phosphite or trans-diaxial carbonyl the molecular structures of examples of each having been determined.'42 The photochemical reactions at 77 K of a series of compounds [alkene.Fe(CO),] are dependent upon the alkene with either allyls or hydrido-allyls identified as The molecular structure of the tricarbonyl derivative [1,2-bis(2',6'-di-isopropylpheny1imino)ethane-NN'Itricarbonyliron has been determined and its m.c.d. and resonance Raman spectra recorded.lM The chelating isocyanide (29) forms complexes [ML3](PF6) (M = Fe z = 2; M = Co z = 3) and ViI+.145 1,2-Ar-O n0-Ar-1,2 ON /PPh \ N N/ ,Fe-H $ C4 OC 'PPh I34 K. Neuenschwander H. U. Giidel J. C. Collingwood and P. N. Schatz Inorg.Chem. 1983 22 1712. 13' E. Banks M. Shone R. F. Williamson and W. 0.J. Boo Inorg. Chem. 1983 22 3339. I36 B. M. Peake M. C. R. Symons and J. L. Wyatt J. Chem. Soc. Dalton Trans. 1983 1171. I37 A. J. Ouderkirk P. Werner N. L. Schulz and E. Weitz J. Am. Chem. SOC.,1983 105 3354. 138 M. Iwamoto H. Kusano and S. Kagawa Inorg. Chem. 1983 22 3365. 139 D. G. Leopold and V. Vaida J. Chem. SOC.,1983 105 6809. 140 D. B. Beach and W. L. Jolly Inorg. Chem. 1983 22 2137. I41 H. C. Ashton and A. R. Manning Inorg. Chem. 1983 22 1440. 142 P. Conway S. H. Grant A. R. Manning and F. S. Stephens Inorg. Chem. 1983 22 3714. I43 J. C. Mitchener and M. S. Wrighton J. Am. Chem. SOC.,1983 105 1065. 144 M. W. Kokkes D. J. Stufkens and A. Oksam J.Chem. SOC.,Dalton Trans. 1983 439. 145 D. T. Plummer and R. J. Angelici Inorg. Chem. 1983 22 4063. Fe Co Ni 227 Protonation of the salt Na+[Fe(CO) NO]- in excess triphenylphosphine affords the new 18-electron hydrido-complex [FeH( CO)( NO)( PPh3)2] which has the distorted trigonal-bipyramidal structure drawn in (30).’& The solid-state and solution struc- tures of the salts M+[Fe(CO),NO]- have been investigated in a study that includes a determination of the molecular structure of the [(Ph,P),N]+ salt in which anion disorder was apparent.14’ This year sees reports of the full characterization of some phosphene complexes (31),’48 (32),’49and (33).I5OA number of sulphane complexes of the type [E.L-S,(C~F~(CO)~](X = 1 2 3 or 4) have been prepared by reaction of the anion on SC12 S2C12 etc.Two examples having x = 3 or 4 were structurally ~haracterized.’~’ /FY0)4 (Me,Si),CH P=P /Fe(CO) (W4Fy /R \ Rip-P=p /\ I ’\R (CO),Fe CH(Si Me,) Fe(C0)4 R I But But The synthesis and characterization of some compounds [Na(thf),],[M{ Fe( CO),},] (M = Zn Cd or Hg) have been described in which metal M bridges the iron atoms in a linear fa~hi0n.l~~ The addition of carbanions e.g. Me,CCN-(R) to 7j4-(l,2- diene)Fe(CO) complexes under a mild pressure of CO followed by methylation leads to the formation of (34). The structure of an intermediate in this reaction has been proposed on spectral evidence.’53 The photochemistry of [( 7j4-cyclo-octatetraene)Fe(CO),] at 12 K in methane has been investigated and analysed with the help of 13C0 labelling in i.r.spectro~copy.”~ The reactions of trimethylphosphite ‘46 M. Cygler F. R. Ahmed A. Forgues and J. L. A. Roustan Znorg. Chem. 1983,22 1026. 147 K. H. Pannell Y. S. Chen K. Belknap C. C. Wu,1. Bernal M. W. Creswick and H. N. Huang Znorg. Chem. 1983 22 418. 148 K. M. Flynn M. M. Olmstead and P. P. Power J. Am. Chem. Soc. 1983 105 2085. I49 K. M. Flynn H. Hope B. D. Murray M. M. Olmstead and P. P. Power J. Am. Chem. SOC.,1983 105 7750. 1 SO A. H. Cowley J. E. Kilduff J. G. Lasch N. C. Norman M. Pakulski F. Ando and T. C. Wright 1. Am. Chem. Soc. 1983 105 7751. 151 M. A. El-Hinnawi A. A. Aruffo B. D. Santarsiero D. R. McAlister and V. Schomaker Znorg. Chem. 1983 22 1585. ’” B.A. Sosinsky R. G. Shong B. J. Fitzgerald N. Norem and C. ORourke Inorg. Chern. 1983,22,3124. 153 M. F. Semmelhack J. W. Herndon and J. P. Springer J. Am. Chem. SOC.,1983 105 2497. R. B. Hitam R. Narayanaswamy and A. J. Rest J. Chem. SOC.,Dalton Trans. 1983 1351. 228 B. W. Fitzsimmons complexes [Fe(CO),- { P(OMe)3}nq4-C,H8R]+ with chloride ion yield phosphonate species arising from CH3 C1 elimination. Investigations have continued on the use of diene( tricarbonyliron) complexes as enantioselective synthons. Diasteriosomeric pairs obtained from nucleophilic attack by chiral phosphines on ( 1-5-q-cyclohexadienyl)irontricarbonyl salts have been separated and successfully deployed in asymmetric induction^.'^^ The reactions Of [q4-C7H8*Fe(Co)3] with diazonium cations have been developed as a route to hydrazone derivative^."^ The possibility of metal-metal double bonding in the dinuclear complex [Fe2(C0)6S2] has been considered and reje~ted.'~' The phosphido-bridged species (35) is a product of methylation of an anion obtained from [Fe2(C0)6( PPh2)2].159 The bridged vinylidenedi-iron complex (36) has been prepared by a multi-step procedure.Me PPh2Me (35) (36) The acetylide complexes (37) undergo a wide range of reactions with amines to yield compounds of the type (38). Some of the broad scope of this reaction has now been revealed.161 R2 \ R'-N+ \7-y.-/H (CO),Fe-Fe(C0)3 \P' Ph/' 'Ph Ph/' 'Ph (37) R = various e.g. Ph But (38) R,R1,R2 = various Electrochemical studies reveal that Prussian Blue deposits from a solution of Fe3+ and [Fe(CN),I4- by two dominant electroreductions and that redox to Prussian Green [Fe1"(CN)6]2,3[Fe11(CN)6],J3 is partially achieved.'62 The 57Fe Mossbauer spectral parameters of a number of pentacyano(base) fer- rates( 11) have been recorded and 1i~ted.I~~ N.G. Connelly A. R. Lucy and M. W. Whiteley J. Chem. SOC.,Dalton Trans. 1983 117. lS6 J. A. S. Howell and M. J. Thomas J. Chem. SOC.,Dalton Trans. 1983 1401. 157 N. G. Connelly A. R. Lucy and J. B. Sheridan J. Chem. SOC.,Dalton Trans. 1983 1465. 158 R. L. DeKock E. J. Baerends and A. Oskam Inorg. Chem. 1983 22 4158. lS9 Y.F. Yu J. Gallucci and A. Wojicki J. Am. Chem SOC.,1983 105 4826. 160 G. M. Dawkins M. Green J. C.Jeffrey,C. Sambale and F. G. A. Stone J. Chem. SOC.,Dalton Trans. 1983 499. 16' G. N. Mott and A. J. Carty Inorg. Chem. 1983 22 2726. I62 R. M. C. Goncalves H.Kellawi and D. R. Rosseinsky. J. Chem. SOC.,Dalton Trans. 1983 991. 163 K. J. Moore L. Lee and J. D. Petersen Inorg. Chem. 1983 22 1244. Fe Co Ni 229 Ferrocene its Derivatives and Related Compounds.-The molecular quad-rupole moments of ferrocene and ruthocene have been determined the results are in agreement with a model in which charge is transferred from ring to metal.164 Electrochemical investigations of [FeCp,]+ and its permethylated analogue in liquid SO2 show both an oxidation and a reduction wave. A magnetic moment of one of the iron( IV)species was Once again the ferrocenium cation has been utilised in the isolation of a new anion.Photo-induced O2oxidation of ferrocene in the presence of BiBr3 yields [Fc]+~[B~~B~,,] with BiOBr as a by-product. The anion has an open double-cubane structure with the intermediate-conformation Fc+ units lying on either side.’66 The interaction of the 19-electron species [CpFe’( q6-C6%)] with dioxygen to give superoxide and an iron(rr) species is shown to be subject to a very strong salt effect.167 The photochemically-induced release of arene from [CpFe(arene)]+ has been studied as a function of anion and solvent; a wide range of quantum yields is observed.’68 Some solvents e.g. acetonitrile play a major role in this reaction. By running the reaction at -40 “C a purple intermediate [CpFe(NCMe),]+PF, was detected and this proved to be a useful intermediate in the preparation of phosphine and phosphate derivatives [CpFe( NCMe)( L)( L’)]+PF6-.16’ An extensive review of the area of [CpFe Arene] chemistry has been p~b1ished.l~’ A series of elaborate ferrocenyl-containing acylating agents have been prepared and their acylating rates with cyclodextrin determined.”’ A full account of the preparation and Mossbauer spectral details of phosphenium cations e.g.(39) has appeared.172 Redox properties of ferrocenylalkyl-substituted quaternary ammonium cations in aqueous organic and molten-salt phases have been determined.’73 The synthesis of cations of the type [FeCp{ PhP(CH2CH2PPh2)2}]+ has been described. They are reduced regioselectively by LiA1H4 via direct attack on the Fe Fe 00 I64 L.D. Ritchie M. K. Cooper R. L. Calvert G. R. Dennis L.Phillips and J. Vrbaneich J. Am. Chem. SOC., 1983 105 5215. I65 P. R. Sharp and A. J. Bard Inorg. Chem. 1983 22 2689. I66 A. L. Rheingold A. D. Uhler and A. G. Landers Inorg. Chem. 1983 22 3255. I67 J.-R. Hamon and D. Astruc J. Am. Chem. SOC.,1983 105 5941. 168 J. L. Schrenk M. C. Palazzotto and K. R. Mann Inorg. Chem. 1983 22 4047. I69 T. P. Gill and K. R.Mann Inorg. Chem. 1983 22 1986. I 70 D. Astruc Tetrahedron 1983 39 4027. 171 R. Breslow G. Trainor and A. Ueno J. Am Chem. SOC.,1983 105 2739. 172 S. G. Baxter R. L. Collins A. H. Cowley and S. F. Sena Inorg. Chem. 1983 22 3475. I73 R. J. Gale K. M.Motyl and R. Job Inorg. Chem. 1983 22 130. 174 S. G. Davies S. J. Simpson H. Felkin F. Tadj and 0.Watts J. Chem. SOC.,Dalton Trans. 1983 981. B. W. Fitzsimrnons Iron-zirconium compounds (40) and (4 1) have been synthesized by metathesis from e.g. Cp2ZrC1Me and K[CPF~(CO)~].~~~ CP\ /Me Zr Photoelectron spectral data backed up by MO calculations reveals a similarity in bonding between ethene and B2H5 in the two species (42) and (43).176 H H \ co H-c I ,co H-bTCO H/ co (42) (43) Nucleophilic replacement of CO by isocyanide in the compound [CpFe( CO)2X] (X = halogen) is catalysed by [CpFe(CO)J2; electron-transfer processes are in~0ked.l~~ A new FeRu dimer (45) has been prepared from (44) by the route shown in Scheme 1.17* (44) (45) Scheme 1 Gamma irradiation of [CpFe(CO),X] (X = C1 or I) affords radical anions which were detected by e.p.r.The spectra are dominated by hfs involving coupling to ha10gen.l~~ The silanes (46) and (47) have been synthesized and characterized.'" Electrophilic attack by the cations [Fe(C0)3( 1-5-pentahaptodienyl)]' (dienyl = C6H7 or 2-MeOC6H,) on reaction with aryltrimethyl-silanes and -stannanes yields a variety of diene-substituted arenes and heterocycles in a reaction that was also studied kinetically.'" 175 C. P. Casy R. F. Jordan and A. L. Rheingold 1. Am. Chem. Soc. 1983 105 665. I76 R. L. DeKock P. Deshmukh T. P. Fehlner C. E. Housecroft J. S. Plotkin and S. G. Shore J. Am. Chem. Soc. 1983 105 815. 1 ?? N. J. Coville M.0. Albers and E. Singleton J. Chem. Soc. Dalton Trans. 1983 947. 178 H. R. Alcock L. J. Wagner and M. Levia J. Am. Chem. Soc. 1983 105 1321. I79 M.C. R. Symons S.W. Bratt and J. L. Wyatt J. Chem. SOC.,Dalton Trans. 1983 1377. 180 W. W. McConnell G. 0. Nelson and M. E. Wright Znorg. Chem. 1983 22 1689. 181 G. R. John L. A. P. Kane-Maguire T. I. Odika and C. Eaborn J. Chem. SOC.,Dalton Trans. 1983 1721. Fe Co Ni 23 1 Me Me Q'iq I 'BF OC-Fe Fe-CO oc \/Lo (46) R = HorMe (47) OC-Fe, oc/ O-S0,CF3 (48) The synthesis and molecular structure of the trifluoromethylsulphonate (48) has been reported.18* Compounds of the type [CpFe(C0)2SPh] react with NOPF to undergo oxidative coupling to the cationic species (49).'83Hydride ion adds initially to the Cp ring Me$Me Me I Me OC-Fe ,Ph 1s oc I (-0 + ph/S' Fe-CO pF6-1 1 Me Me (49) and then to the alkyne to yield an alkene in which H i's cis to the iron atom (50) +(51) (Scheme 2).lg4External-source CO adds to the carbene (52) to yield (51) Scheme 2 182 M.B. Humphrey W. M. Lamanna M. Brookhart and G. R. Husk inorg. Chem. 1983,22 3355. 183 P. M.Treichel L. D. Rosenhein and M. S. Schmidt inorg. Chem. 1983,22 3960. I84 D.L.Reger K. A. Belmore J. L. Atwood and W. E. Hunter J. Am. Chem. SOC.,1983 105 5710. B. W. Fitzsimmons the ketene derivative (53) (Scheme 3) which is stable at ambient temperat~re.'~~ Photochemically-induced substitution of CO in [CpFe( CO),] by phosphine or phosphite yields a single mono-substituted product a radical mechanism is involved.186 Enantioselective cyclopropane synthesis has been achieved by reaction of [CpFe(CO),:CRR]+ with alkenes and it is shown that chiral carbenes of the type [Cp(CO)( PR,)Fe:CHR]+ will be generally useful for asymmetric synthesis of cyclo- propanes.187 2 Cobalt Low Oxidation-state Compounds of Cobalt.-Dicobalt octacarbonyl is a catalyst in the transformation of alkyl acetates into [(trialkylsiloxy)methylene]alkanes (54) -+ (55) (Scheme 4).lg8 It reacts photochemically with [co2(co)&] (L = phosphine) to give an equilibrium mixture of the starting compound [Co2(C0),L2] (55) R = various Scheme 4 and [CO,(CO)~L]. Kinetic evidence in favour of a homolytic fission mechanism is presented and a reaction scheme The complexes [Co(CO)L(Cp)] (L = P( C6H1 1)3 or PPh3) undergo one-electron electrochemical oxidation to the corres- ponding radical-cations.Chemical oxidation with ferrocenium hexafluorophosphate gives [CO(Co)L(Cp)]+(PF,)- with L = P(C6H11)3.If L = PPh3 the product is [CoL2(Cp)]+( PF6)-. Substitution reactions to give paramagnetic [CoL{P(C,H ,),)Cp]+(PF6)- (L = PPh or pyridine) are also reported.'" Nitrosonium hexafluorophosphate reacts with [Co(CO) (Cp)] to yield [Co,( p-CO)(p-NO)( Cp),]PF, which can be subsequently chemically or electrochemically reduced to the paramagnetic complex [Co2( p-NO)(Cp)2].'91 The molecular structure I85 T. W. Bodner and A. R. Cutler J. Am. Chem. SOC. 1983 105 5926.I86 D. R. Tyler M. A. Schmidt and H. B. Gray J. Am. Chem. SOC.,1983 105 6018. 187 M. Brookhart D. Timmers J. R. Tucker G. D. Williams G. R. Hurk H. Brunner and B. Hammer J. Am. Chem. SOC. 1983 105 6721. I88 N. Chatani S. Murai and N. Sonoda J. Am. Chem. SOC.,1983 105 1370. 189 R. W. Wegman and T. L. Brown Inorg. Chem. 1983 22 183. I90 K. Broadley N. G. Connelly and W. E. Geiger J. Chem. SOC.,Dalton Trans. 1983 121. 191 N. G. Connelly J. D. Payne and W. E. Geiger J. Chem. Soc. Dalton Trans. 1983 295. Fe Co Ni 23 3 of the p-methylene dicobalt species (56) one of a range of compounds prepared by the action of gem-di-iodoalkanes on Na[Cp(CO)] has been e~tab1ished.l~~ The Me Mk (56) compounds (57) e.g. R’= R2= H;R3= Bun,R4= C1 have been prepared in good yields by the reaction of the compound (58) with a1k~nes.I~~ (57) R1-4= various (58) R1,R2 = various The mechanism of the reduction of [v4-(1,5 -C8 H,)CoCp] to the isomerized anion [( 1,3-c8 H8)CoCp]- has been established using electrochemical technique^.'^^ The adduct [{(CO),Co},alkyne] reacts with MeCN or other Lewis bases under conditions of electron-transfer catalysis to yield mono- or di-substitution products e.g.[(CF,),Co,(CO),L] (L = MeCN phosphine or pho~phite).’~’ The kinetics of the reaction between [Cp( R3P)Co.alkene] complexes and alkenes to yield cobaltacyclopentadienes (59) has been investigated and mechanisms advanced.196 Alkynes react readily with the phosphine complexes [CoBr( PMe,)3] to yield a range of mononuclear alkyne-cobalt complexes of which (60) is one example others to be fully structurally characterized include (61) which has a molecule of co-ordinated ~olvent.’~’ (59)R1-4= various (60) (61) I92 K.H. Theopold and R. G. Bergman J. Am. Chem. SOC. 1983 105 464. I93 I. T.Horvath G. Paiyi L. Marko and G. D. Andreetti Inorg. Chem. 1983 22 1049. 194 M. Grzeszczuk D. E. Smith and W. E. Geiger J. Am. Chem. Soc. 1983 105 1772. 195 M. Arewgoda B. H. Robinson and J. Simpson J. Am. Chem. Suc. 1983 105 1983. 196 Y. Wakatsuki 0. Nomura K. Kitaura K. Mokokuma and H. Yamazaki J. Am. Chem. SOC.,1983,105 1907. 197 B. Capelli M. Dartinguenave Y. Dartinguenave and A. L. Beauchamp J. Am Chem. SOC.,1983,105 4662. 234 B.W. Fitzsimmons MO calculations have been carried out for a range of compounds of the type [CpCo(CO),]. These reveal the origin of the bond length alternation as observed in crystallographic studies to be the intramolecular interruption of the conjugated system.'98 The dicobalta cyclohexane (62) demetallates on reaction with phosphines. Both the organic and inorganic products from this have been identified and a reaction scheme established.'99 w Q G?2,Q ,C? co-co ago gD \-co ss An interesting case of a reversible reaction (63) e(64) in a single crystal has been discovered and studied both crystalline phases have the same space group.200 The 59C0 nuclear quadrupole resonance spectra of a range of compounds typified by [CpCo( 1,2-benzoquinone)] have been recorded and interpreted."' Compounds of Cobalt(II).-The oxidation of water to oxygen by [Ru bipy313+ is catalysed by cobalt(I1) ions.A detailed study of the kinetics of this process has revealed that a cobalt(1v) compound is involved.202 The Angular Overlap Model has been applied in an e.p.r. study of a range of cobalt(I1) complexes in which anisotropic bonding interactions were inve~tigated.~'~ Complexes of formula [CoXL,] are either dimeric or polymeric for a wide range of X and L. The factors favouring either form have now been analysed the~retically.~'~ Variable-temperature 'H n.m.r. studies of complexes [ML2(RC02),] {M = Co" or Ni"; L = 3MePy 4MePy or 4EtPy (Py = pyridine); R = CF, CF2H CFH2 or C3H7} have led to a determination of accurate activation energies for cis-trans con~ersion.~'~ The six-co-ordinate antiferromagnetic co-ordination polymer [Co bipy( NCS)2] (bipy = bipyridyl) has been prepared and a zig-zag chain structure established by X-ray methods.206 Although the octahedral complex ion [Co bipy312+ is long-established as a high-spin complex with S = 3/2 it now emerge.that it lies close to the cross-over point an e.p.r. study of this ion as embedded in zeolite-Y reveals a spin-equili- bri~m.~'~ J. W. Chinn and M. B. Hall J. Am. Chem. Soc. 1983 105 4930. I99 W. H. Hersh and R. G. Bergman J. Am. Chem. SOC.,1983 105 5846. 2oo E. J. Miller T. B. Brill A. L. Rheingold and W. C. Fultz J. Am. Chem. SOC.,1983 105 7580. 20 I E. J. Miller and T. B. Brill Inorg.Chem. 1983 22 2392. 202 B. S. Braunschwig M. H. Chou C. Creutz P. Ghosh and N. Sutin J. Am. Chem. Soc. 1983 105,4832. 203 A. Bencini C. Benelli D. Gatteschi and C. Zanchini Znorg. Chem. 1983 22 2123. 204 E. Canadell and 0. Eisenstein Inorg. Chem. 1983 22 2398. *05 A. Goodacre and K. G. Orrell J. Chem. Soc. Dalton Trans. 1983 153. 206 B. W. Dockum G. A. Eisman E. H. Witten and W. M. Reiff Inorg. Chem. 1983,22 150. 207 K. Mizuno and J. H. Lunsford Inorg. Chem. 1983 22 3484. 19' Fe Co Ni 235 The molecular structures of two closely related complexes differing by one unit of oxidation have been determined with a view to comparing electron-transfer reactivity. These are [Co' bipy,]Cl and [Co"bipy,]Cl,. Geometrical changes are very small if compared with the corresponding Co"/Col" couple.208 t-Butyl peroxide reacts with bis( dimethylglyoximato)cobalt( 11) to yield an organocobalt complex.The dependence of product and stoicheiometry upon solvent has been determined in a study of the kinetics.209 The molecular structure of a bis-nitrosyl iodo-complex [CoI( NO) PPh,] has been determined in a 203 K X-ray diffraction study. The nitrosyls are nearly linear in this tetrahedral species and the authors suggest that observations of bent nitrosyls in this stereochemistry may be a result of disorder.210 The structure of another nitrosyl [Co( NO){S,CN( Pri)2}2] has been determined it has a significantly bent NO in the familiar [MS,(NO)] structure. It is noted that this compound is isomor- phous with the iron analogue in which the nitrosyl is perfectly linear.211 As preliminary work to studying [CoS,] chromophores in enzyme systems the circular dichroism and m.c.d.of a range of mononuclear and polynuclear systems have been recorded to establish spectral differences between bridging and terminal thiolates.,12 The complex [Co"(L,Rb)] where L = (65) has been prepared its structure determined and a comparison made with that of the analogous potassium compound with a view to investigating its Rb/K selectivity.,13 The oxidation path- ways of the complex [Co1*(L)Cl]C104 where L = (66),and its Ni" bis-thiocyanato analogue in reactions with [Fe phenJ3+ have been investigated.,14 A green complex CH,C02H U (65) (66) [Co (tren),( OH)]( C1OJ3 (tren = tris[2-(amino)ethylamine)has been characterized by means of electronic spectroscopy and magnetic s~sceptibility.~'~ The kinetics of the bromate oxidation of the cobalt( 11) complex of trans-cyclohexane- 1,2-diamine N,N,N' N'-tetra-acetic acid have been followed and a mechanism advanced.216 The complexes (67),2'7 (68),,18 (69),'19 and (70),,*O form 1 :1 adducts with dioxygen.208 D. J. Szalda C. Creutz D. Mahajan and N. Sutin Inorg. Chem. 1983 22 2372. 209 J. H. Espenson and J. D. Melton Inorg. Chern. 1983 22 2779. 210 B. L. Haymore J. C. Huffman and N. E. Butler Inorg. Chem. 1983 22 168. 21 I G. A. Brewer R. J. Butcher B. Letafat and E. Sinn Inorg. Chem. 1983 22 371. 212 M. Nakata N. Ueyarna A. Nakarnura T. Nozawa and M. Hatano Inorg.Chem. 1983 22 3028. 213 D. L. Hughs and J. N. Wingfield J. Chem. Soc. Dalton Trans. 1983 915. 214 J. A. Switzer J. F. Endicott M. A. Khalifa F. P. Rotzinger and K. Kirnar J. Am. Chem. Soc. 1983 105 56. 215 A. Bencini C. Benelli and D. Gatteschi Inorg. Chem. 1983 22 470. 216 M. P. Pujari and P. Banerjee J. Chem SOC.,Dalton Trans. 1983 1015. 217 D. A. Roberts J. M. Busch Y. Tsao V. Katovic J. J. Fortman and S. C. Curnmings Inorg. Chem. 1983 22 1804. 2'8 R. Machida E. Kimura and M. Kodarna Inorg. Chem. 1983 22 2055. 219 P. Zanello R. Cini A. Cinquantini and P. L. Orioli J. Chem. SOC.,Dalton Trans. 1983 2159. 220 M. D. Braydich J. J. Fortman and S. C. Cumrnings Inorg. Chem. 1983 22 484. B. W.Fitzsimmons H H \ / N -(CH z)n -N 'N /W& Nj H (67) 2-X or 4-X=H Me OMe Br or C1; Y =0 or S (68) n =0 1 2 3 4 5 or 6 (69) R =H X =H 3-OMe 4-OMe 5-OMe H Me 5-Cl or 5-N02;R =Me X =H 3-OMe (70) R =H Me or Ph; 4-OMe 5-OMe 5-C1 or 5-N02 R' =Me CF, or Ph The six-co-ordinate cobalt(I1) complexes [Co(salen)L] (L =pyridine or other nitrogen bases) are found to have S =3/2 in solution the magnetic moments vary with temperature and a spin-equilibrium is likely.221 As with other spin-crossover systems a search has been made for possible influences of this on electron-transfer rates.222 Cobalt( 11) and nickel( 11) complexes of 2,6-bis benzoyl hydrazone have been prepared and ~haracterized.~~~ As is evident from the above the bulk of work reported this year has been on nitrogen-donor ligands.A few papers dealing with phosphorus and sulphur ligands were noted. The complex (71) has been prepared and characterized224 and 1,4,7-trithianonane has been reported to form complexes of formula [ML,](BF,) (M = Co Ni or CU).~~~ A phosphorus-donor ligand (72) has been synthesized and its cobalt(11) and nickel( 11) complexes synthesized and fully characterized.226 Cobalt(rn) Compounds.-The oxidation of 2,6-di-t-butyl phenol by dioxygen is catalysed by the p-peroxo-compound tetrakis( bipyridyl)( p-peroxo)p-22 I K. Migita M. Chikara and M. Iwaizumi Inorg. Chem. 1983 22 2281. 222 T. Zhu C. H. Su B. K. Lemke L. J. Wilson and K. M. Kadish Inorg. Chem. 1983 22 2527. 223 C. Lorenzini C. Pelizzi G. Pelizzi and G. Predieri J.Chem. SOC.,Dalton Trans. 1983 721. 224 C. Bianchini and A. Meli 1. Chem. SOC.,Dalton Trans. 1983 2419. 22s W. N. Setzer C. A. Ogle G. S. Wilson and R. S. Glass Inorg. Chem. 1983 22 266. 226 M. Ciarnpolini P. Daporto N. Nardi and F.Zanobini Inorg. Chem. 1983 22 13. Fe Co Ni 237 hydroxodicobalt(III).~~’The transfer of energy from the ’Eg state of [Cr bipyJ3+ to [Co(NH3)6I3+ has been studied in aqueous solution. Electronic energy transfer takes place.,,’ Complexes of cobalt( 111)with hydroxamic acid have been shown to undergo a spin-crossover induced by pr~tonation.~~~ The crystal structure of the compound cis-a-A( -)589-[C~{( +)PAPH},eniMy]+CI- has been determined by X-ray methods.230 The complex PAPH is the mono-ion of 1-phenyl-2-amino- 1,3-dihy- drox ypropane.(p)-[{Tris (2-aminoethyl) amine}{ 2-(dih ydroxymethy1)gl ycinate}]-cobalt( 1II)zinc tetrachloride-water has been prepared its molecular structure solved and its chemistry in~estigated.~~’ Cobalt-59 n.m.r. spectra of a wide range of octa-hedral cobalt( 111) compounds have been recorded and analy~ed.’~~ The electro- chemistry of macrobicyclic cobalt(m) complexes has been studied and a number of metal-centred and ligand-centred reductions identified.233 The complex [en2Co{ (S)CHCONH( Et)CO(CH,) NH,}] has been synthesized and its structure determined234 and a M2+sequestering agent [en2Co{0,P(OH)CH2P(OH)02}]C104 has been prepared its structure determined and its association constant with Ca2+ determined.235 Surprisingly P4Nz donor sets are uncommon in cobalt( 111) chemistry the preparation of cis-and trans-[Co{ (EtO),P},( NCS)J+ has been achieved and the structure of the trans isomer determined.236 Cobalt(111) Compounds.Properties of several compounds are shown in Table 2 237-259 2. 227 S. A. Bedell and A. E. Martell Inorg. Chem. 1983 22 364. 228 M. T. Gandolfi M. Maestri D. Sandrini and V. Balzani Inorg. Chem. 1983,22 3465. 229 K. Abu-Dari S. J. Barclay P. E. Riley and K. N. Raymond Inorg. Chem. 1983 22 3085. 230 A. Clearfield P. Rudolf and J. G. Wardeska Inorg. Chem. 1983 22 2713. 23 I W. G. Jackson G. M. McLaughlan A. M. Sargeson and A. D. Watson J. Am. Chem. SOC.,1983 105 2426. 232 N. Juranic Inorg. Chem. 1983 22 521. 233 A. M. Bond G.A. Lawrance P. A. Lay and A. M. Sargeson Inorg. Chem. 1983 22 2010. 234 L. Roecker M. H. Dickman D. L. Nosco R. J. Doedens and E. Deutsch Inorg. Chem. 1983,22,2022. 235 S. S. Jurissson J. J. Benedict R. C. Elder R. Whittle and E. Deutsch Inorg. Chem. 1983 22 1332. 236 G. Albertin G. Pelizzi and E. Bordignon Inorg. Chem. 1983 22 515. 237 E. J. Evans C. J. Hawkins J. Rodgers and M. R. Snow Inorg. Chem. 1983 22 34. 238 J. M. Harrowfield A. M. Sargeson J. Springborg M. R. Snow and D. Taylor Inorg. Chem. 1983 22 186. 239 R. D. Peacock J. Chem. SOC.,Dalton Trans. 1983 291. 240 N. Juranic and R. D. Lichter J. Am. Chem. SOC.,1983 105 406. 24 1 C. B. Storm C. M. Freeman R. J. Butcher A. H. Turner N. S. Rowan F. 0.Johnson and E. Sinn Inorg.Chem. 1983 22 678. 242 A. Yamagishi J. Chem. SOC.,Dalron Trans. 1983 679. 243 W. G. Jackson and C. M. Begbie Inorg. Chem. 1983 22 1190. 244 G. R. Brubaker and D. W. Johnson Inorg. Chem. 1983 22 1422. 245 W. Clegg C. D. Garner and M. H. Al-Samman Inorg. Chem. 1983 22 1534. 246 H. Okazaki U. Sakaguchi and H. Yoneda Inorg. Chem. 1983 22 1539. 247 U. Sakaguchi A. Tsuge and H. Yoneda Inorg. Chem. 1983 22 1630. 248 U. Sakaguchi A. Tsuge and H. Yoneda Inorg. Chem. 1983 22. 3745. 249 K. D. Grande A. J. Kumin L. S. Stuhl and B. M. Foxman Inorg. Chern. 1983 22 1791. 250 J. N. Cooper C. A. Pennell and B. L. Johnson Inorg. Chem. 1983 22 1956. 25 I T. Damhus and C. E. Schaffer Inorg. Chem. 1983 22 2406. 252 M. Watabe M. Takahashio and A.Yamasaki Inorg. Chem. 1983 22 2650. 253 D. A. Buckingham C. R. Clark and R. F. Tasker Inorg. Chem. 1983 22 2772. 254 D. A. Buckingham C. R. Clark M. M. Deva and R. F. Tasker Inorg. Chem. 1983 22 2754. 255 J. N. Cooper J. G. Bentsen T. M. Handel K. M. Strohmaier W. A. Porter B. C. Johnson A. M. Carr D. A. Farnath and S. L. Appleton Inorg. Chem. 1983 22 3060. 256 P. J. Toscano and L. G. Marzilli Inorg. Chern 1983 22 3342. 257 A. M. Bond A. R. Hendrickson R. L. Martin J. E. Moir and D. R. Page Inorg. Chem. 1983,22,3440. 258 A. F. Lindmark and R. C. Fay Inorg. Chem. 1983 22 2000. 259 C. J. Hawkins and J. Martin Inorg. Chem. 1983 22 3879. Table 3 Complex or System [Co( NH,),tripeptide] [Co en2{(S)-Tyr}12' [Co acac,] [Co(ox),(gl~),(en),l [Co(NH,),(4-NO,-imidazo1ato)lCl [Co acac2.amino acid] A( +)-[Co en2C1,]+ truns-[CoC~,L',] [cO I2 (OH)6(CH3 C02)6L21 21 [CO en,] [coL33I B.W.Fitzsimmons Study Ref Determination of structure 237 Reaction with MeCHO 23 8 C.D. study 239 "N n.m.r. 240 Determination of structure 24 1 Montmorillonite clay resolution 242 Bailar inversion 243 Preparation 244 Determination of structure 245 C.D. study 246 247 248 &[(CN),CoC(CO Me)=C(CO,Me)Co(CN),] cis-and trans-[Co en,(NO,)(ox)] Chirality reference system [Co bis( a asp)] [Co en,aa] trans-[Co en2C1(S,0,)] [CO L41(N03)2 [CO(S C NRd3I [CO(S,C NRAI tr~ns-[Co(NH,)~gly-gly-~-his] Determination of structure 249 Bonding of oxalate 250 -25 1 "N n.m.r.252 Liquid chromatography 253 254 Preparation 255 Determination of structure 256 Electrochemistry 257 Rotation kinetics 258 Preparation 259 en = 1,2-diaminoethane; tyr = tyrosinato; acac = pentan-2,4-dionato; gly = glycinato; ox = oxalato; L' = 1,lO-diamin0-2,9-dimethyl-3,7-diazadecane; L2 = 6-methyl-2-oxypyridine; L3 = 1,I ,I-tris(2-aminoethy1)aminoethylethane;L4H= NH2CH2CONH(CH2)S(CH2)NH2 Cobalt(11:) Complexes. Recent papers on reaction kinetics are listed in Table 4.26L289 260 M. A. Hussein A. A. Abdel-Khalek and Y.Sulfab J. Chem. SOC Dalton Trans. 1983 317. 26I D. Smith M. F. Amira P. B. Abdullah and C. B. Monk J. Chem. SOC.,Dalton Trans. 1983 337. 262 R. van Eldik Inorg. Chem. 1983 22 353. 263 R.C. McHatton and J. H. Espenson Inorg. Chem. 1983 22 784. 264 A. C. Dash Inorg. Chem. 1983,22 837. 265 A. Ichimura D. L. Nosco and E. Deutsch J. Am. Chem. Soc. 1983 105 844, 266 W. G. Jackson M.L. Randall A. M. Sargeson and W. Marty Inorg. Chem. 1983 22 1013. 267 I. M. Sidahmed and C. F. Wells J. Chem. Soc. Dalton Trans. 1983 1035. 268 M. S. Ram A. H. Martin and E. S. Gould Inorg. Chem. 1983 22 1103. 269 P.B. Abdulla and C. B. Monk J. Chem. SOC.,Dalton Trans. 1983 1175. 270 W. L. Purcell Inorg. Chem. 1983 22 1205. 27I H. Cohen E. S. Gould D. Meyerstein M. Nutkovich and C. A. Radlowski Inorg. Chem. 1983,22 1374. 272 R. J. Balahura W. C. Kupferschmidt and W. L. Purcell Inorg. Chem. 1983,22 1456. 273 C. Poon T. Lau C. Wong and Y. Kan J. Chem.SOC.,Dalton Trans. 1983 1641. 274 S. Balt H.J. A. M. Kuipers and W. E. Renkema J. Chem. SOC.,Dalton Trans. 1983 1739. 275 K. Miyoshi N. Katoda and H. koneda Inorg. Chem. 1983 22 1839. 276 W. L. Reynolds M.Glavas and E. Dzelilovic Inorg. Chem. 1983 22 1946. 277 P. M. Coddington and K. E. Hyde Inorg. Chem. 1983 22 2211. 278 P. A. Lay A. W. H. Mau W. H. F. Sasse I. I. Creaser L. R. Gahan and A. M.Sargeson Inorg. Chem. 1983 22 2347. 279 S. Balt H.J. GameIkoorn and W. E. Renkema 1. Chem. SOC.,Dalton Trans. 1983 2415. 280 R. V. Dubs L. R. Gahan and A. M. Sargeson Inorg. Chem. 1983 22 2523. 28I P. M. Balasubramanian and E. S. Gould Inorg. Chem. 1983 22 2635. t82 M. F. Hoq,C. R. Johnson S.Paden and R. E. Shepherd Inorg. Chem. 1983 22 2693.Fe Co Ni 239 Table 4 Complex Reaction Ref [Co"(nta) (H2 0121 Periodate oxidation 260 [CO(NH~)S~~CRI Aquation 261 [so3Co(NH3),I+ Electron transfer 262 [Fc0(NH3>,12' Reduction 263 [salCo( NH,),]" Hydrolysis 264 Cleavage 265 [~~,CO(RSS)(CH~)~NH~]~+ [Co(NH3)5XIn+ Hydrolysis 266 truns-[CoCI Py,]+ Solvol ysis 267 [CO( NH,) (02 cWl2+ Reduction( Ti3+) 268 [Co(NH,) (02CR)I2+ Aquation 269 [WNH3),(tet)l2' Linkage isomerism 270 [Co( NH3),O2CR7+ Reduction( R- ) 27 1 + [Co(NH,),NCR] Reduction( C8+) 272 [Co en,AX]+ Ligand substitution 273 [Co( NH3),0N0I2+ Linkage isomerism 274 [Co( NH3),ON0l2+ Linkage isomerism 275 [Co( NH,),Cl]'+ Aquation 276 [CO en2(CO3)2I3- Decarboxylation 277 [CO( cage)13 Electron transfer 278 + + Solvolysis ~~u~~-[CO(NH,),('~NH~)X]~~'~ 279 + [CO( age)]^+/^ Self-exchange 280 Cobalimine Reduction 28 1 [Co( NH3),meimidI3+ Isomerism 282 trans-[Co( NH3),C12]+ Ammoniation 283 [Co(NH,),NCRI3+ Reduction( C8') 284 [Co( NH,) ,imidazoleI3+ Reduction 285 [Co sep13 + Electron transfer 286 [CO sep13+ Electron transfer 287 [Co(NH3),NCNMe213+ Hydration 288 [Co en3I3+ Reduction 289 nta = nitriloacetete; sal = salicylato; ox = oxalato; tet = tetrazolato; meimid = 4-methylimidazole; cage = 1-methyl-3,13,16-trithia-6,8,10,19-tetra-azabicyclo[6.6.6]eicosane(one of a large group of cage ligands used by these worker see this and earlier papers for full details).sep = 1,3,6,8,10,13,16,19-octa-azabicyclo[6.6.6]eicosane 3 Nickel Low Oxidation States of Nickel.-The new dinitrogen complex [Ni(CO) N2] can be generated in a pressure cell by U.V.photolysis of tetracarbonylnickel in liquid krypton. The decomposition of this complex was followed over the temperature range I 12-1 27 K and a value of the Ni- N2bond dissociation energy determined.290 Two classes of Ni-CS2 co-ordination compound have been prepared by reaction of CS2 with Nio phosphine complexes and the molecular structure of an example 283 S. Balt H. J. Gamelkoorn H. J. A. M.Kuipers and W.E. Renkema Znorg. Chem 1983 22 3072. 284 R.A. Balhura and A. J. Johnston Znorg. Chem. 1983 22 3309. 285 H.A. Boucher G. A. Lawrance A. M.Sargeson and D. F. Sangster Znorg. Chem. 1983 22 3482. 286 J. F. Endicott G. R. Brubaker T. Ramasami K.Kumar K. Dwarakanath J. Cassel and D. Johnson Znorg. Chem. 1983,22 3754. 287 I. F.Creaser A. M.Sargeson and A. W. Zanella Znorg. Chem. 1983,22,4022. 288 N.E.Dixon D. P. Fairlie W. G. Jackson and A. M. Sargeson Znorg. Chem. 1983 22 4038. 289 M.Kanesato M.Ebihara Y. Saseki and K. Saito J. Am. Chem. SOC. 1983 105 571 1. 290 J. J. Turner M. 9. Simpson M. Poliakoff and W. B. Maier J. Am. Chem. Soc. 1983,105,3898. B. W. Fitzsimmons (73) of one class established.291 Fourier-transform mass spectrometry has been used to study the structures of NiC,H2,+ complexes generated by reaction of’Nif with a range of hydrocarbons.292 Bis( q3-allyl)nickel(o) and bis( q5-pentadienyl)iron( 11) have been used as starting materials in the preparation of [Ni(PF3)J Ni(PF2H),] /s, Me P -C-N i-PMe, I I s ,s C II S (73) and [Fe( PF3)5].293 The gas-phase U.V.photoelectron spectra of a range of Ni-alkyne complexes have been recorded spectral features related to ionizations from molecular orbitals involved in nickel-alkyne back-bonding have been established.294 Tertiary phosphines co-ordinated to truns-[NiRXL2] or trans-[NiXL,’] (R = CC1=CC12 or C,H,Me3-2,4,6; X = halide pseudohalide or CECR’) have been shown to exchange in benzene.295 The dinuclear complex [(tppme)Ni(p-CS3) Ni(tppme)]BPh,(tppme = 1,1,1-tris(dipheny1phosphinomethyl)ethane) has together with related compounds been synthesized and ~haracterized.~~ Nickel(r1) Compounds.-Potentiometrically determined stability constants of tetra-azacycloalkane complexes of Ni” have been obtained.297 Some trans-octahedral- [Ni( N4S2)] complexes [NiL2I2+ (L = 1-thia-4,7-diazacyclononane)have been pre- pared and structurally ~haracterized.~~~ trans-Tetramminedinitritonickel(I1)has been closely examined with a view to clarifying the nature of the bonding.An X-ray diffraction study conducted at 110 K reveals an aspherical electron distribution about the and the results of a polarized neutron diffraction study were shown to complement one another in establishing a bonding A series of macrocyclic ligands have been prepared with the aim of designing one in which co-ordination is impossible unless ligand folding takes place.301 The ligands (74) (74) X = CN or CH,NH 29 1 M. G. Mason P. N. Swepston and J.A. Ibers Inorg. Chem. 1983 22 41 1. 292 D. B. Jacobson and B. S. Freiser J. Am. Chern. Soc. 1983 105 736. 293 S. J. Severson T. H. Cymbaluk R. D. Ernst J. M. Higashi and R. W. Parry Inorg. Chem. 1983,22,3833. 294 M. Casein D. Ajo G. Granozzi E. Tondello and S. Aime J. Chem. SOC.,Dalton Trans. 1983 869. 295 M. Wada and K. Nishiwaki J. Chem. SOC.,Dalton Trans. 1983 1841. 296 C. Bianchini P. Innocenti and A. Meli J. Chem. SOC.,Dalton Trans. 1983 1777. 29’ M. Micheloni P. Paoletti and A. Sabatini J. Chem. SOC.,Dalton Trans. 1983 1189. 298 S. M. Hart J. C. A. Boeyens J. P. Michael and R. D. Hancock J. Chem. SOC.,Dalton Trans. 1983 1601. 299 B. N. Figgis P. A. Reynolds and S. Wright J. Am. Chem. SOC.,1983 105 434. 300 B. N. Figgis P. A. Reynolds and R.Mason J. Am. Chem. SOC.,1983 105,440. 301 K. R. Adam A. J. Leong L. F. Lindoy H. C. Lip B. W. Skelton and A. H. White J. Am. Chem. SOC. 1983 105 4645. Fe Co Ni 24I were prepared and complexation with Ni" under neutral conditions leads to high- spin five-co-ordinate species.302 The extraction rates of Ni" or Zn" with ethyl- dithiazone butyldithiazone or hexyldithiazone in CHC13 are found to be first-order in ligand or metal and inverse first-order in hydrogen-ion c~ncentration.~'~ Nickel phthalocyanin iodide [Ni( Pc)I] is found to exhibit metallic conductivity at low temperature^.^'^ [(5,10,15,20-Tetramethylporphinato)nickel(II)] partially oxidized with iodine contains the 13-anion and the material exhibits metallic-like conduc- ti~ity:~"the charge density over the parent compound has been investigated by low-temperature crystallography and the results compared with a calculated set of electron-density maps.306 Red-shifts are observed in the optical spectra of protonated nickel(11) p~rphyrins.~~' Muonium atoms in aqueous solutions were shown to interact differently with the two alternative spin-states of [nickel( ~~)cyclam]- (cyclam = I ,4,8,11 -tetra-azacyclotetradecane),spin-state switching being brought about by changing the ionic strength of the medium.308 The crystal structure of the complex (75) has been determined.309 A family of macrobicyclic ligands has been Et Et Et -Et (75) designed in which a substrate might be held close to a metal centre as a guest molecule in a clathrate.Some complexes of this design have been prepared?" In a further paper on this theme host-guest interactions have been investigated using n.m.r. methods.311 The square-planar complex (76) has been prepared and character- i~ed.~'~ The chemisorption of dioxygen carbon monoxide and other small molecules on clean (1 11) surfaces of Nisi has been studied using a wide range of techniques. Some (02,CO and C02 are observed to dissociate at 170K but neither H2 nor N2 absorbs.313 (76) 302 K. P. Wainwright J. Chem SOC.,Dalton Trans. 1983 1149. 303 H. Watarais and H. Freiser J. Am. Chem. SOC. 1983 105 189. 304 J. Martinsen R. L. Greene S.M. Palmer and B. M. Hoffman J. Am. Chem. SOC.,1983 105,677. 305 L. J. Pace J. Martinsen A.Ulman B. M.Hoffman and J. A. Ibers J. Am. Chem. SOC.,1983 105 2612. 306 F. W. Kutzler P. W. Swepston 2.Beerkovitch-Yellin D. E. Ellis and J. A. Ibers J. Am. Chem. SOC. 1983 105 2996. 307 D. Ward P. M. Callahan R. Young G. T. Babcock and C. K. Chang J. Am. Chem. SOC.,1983,105,634. 308 J. M. Stadlbauer B. W. Ng,Y. C. Jean and D. C. Walker J. Am. Chem Soc. 1983 105 752. 309 P. W. Hitchcock J. Chem. SOC.,Dalton Trans. 1983 2127. 310 K. J. Takeuchi D. H. Busch and N. Alcock J. Am. Chem SOC.,1983 105 4261. 31 1 K. J. Takeuchi and D. H. Busch J. Am. Chem. SOC.,1983 105 6812. 3'2 J. L. Davidson P. N. Preston and M. V. Russo J. Chem. SOC.,Dalton Trans. 1983 783. 313 L. H. Dubois and R. G. Nuzzo J. Am. Chem. SOC.,1983 105 365. 242 B. W.Fitzsimrnons Reaction Kinetics of Nickel( zz) Complexes.Table 5 lists recent papers.31L324 Table 5 Reaction Rex Ni2+ + isoquinoline + complex 314 Ni2+ + 2-(2-pyridylazo)-1-naptho1 complex 315 [Ni en212+ + PO:-+ product 3 16 Ni2+ + C1-+ complex 317 Ni2+ + salicylate --* complex 318 [Ni'"cplx] + Fe2+ -+ reduced complex 319 Ni2+ + dicarboxylic acid -* 320 Ni2+ + hydroxy-acid -complex complex 321 planar Ni" complex + octahedral complex 322 Ni2+, + water exchange 323 [Ni ll/lllpeptide] -+ electron transfer 324 High Oxidation States of Nickel.-The molecular structure of the ion-radical salt bis(maleodithiolato)nickelate(111) has been solved and its electronic structure investigated.325 These higher oxidation states of nickel often involve five-co-ordina- tion as in the compounds (77) X-ray analysis of the iodo-derivative reveals essen- tially square-pyramidal Two products of chlorination of [Ni en2C12] have Me N -,N i X,+ N Me, Ill (77) X = CI Br or I been ~haracterized.~~' These are trans-[Ni"'en2CI2]C1 and a mixed-valence com- pound [Ni"en2Ni1Ven2C12]C14.Pulse radiolytic studies of [1,4,7,10,13-penta-aza-cyclohexadecane)nickel( II)] reveal oxidative processes yielding Ni"' Cluster Compounds of Iron Cobalt and Nickel.-Table 6 lists recent papers.329-354 314 K. Ishari S. Funahashi and M. Tanaka Inorg. Chem. 1983 22 2564. 315 R. L. Reeves G. S. Calabrese and S. A. Harkaway Inorg. Chem. 1983 22 3076. 316 R. A. Read and D. W. Margerum Inorg. Chem. 1983 22 3447 317 S. A. Cower H.W. Dodgen and J. P. Hunt Znorg. Chem. 1983 22 1952. 318 S. Chopra and R. B. Jordan Inorg. Chem. 1983 22 1708. 319 D. H. Macarthy and A. McAuley Inorg. Chem. 1983 22 2062. 320 T. Inoue K. Kojima and R. Shimozawa Inorg. Chem. 1983 22 3972. 321 T. Inoue K. Sughara K. Kojima and R. Shimozawa Inorg. Chem. 1983 22 3977. 322 A. F. Godfrey and J. K.Beattie Inorg. Chem. 1983 22 3794. 323 H. W. Dodgen and J. P. Hunt Znorg. Chem. 1983 22 1146. 324 C. K. Murray and D. W. Margerum Inorg. Chem. 1983 22 463. 325 B. L. Ramakrishna and P. T. Manoharan Inorg. Chem. 1983 22 21 13. 326 D. M. Grove G. van Koten R. Zoet N. W. Murrall and A. J. Welch J. Am. Chem. SOC.,1983,105,1379. 327 D. A. Cooper S. J. Higgens and W. Levason J. Chem. SOC.,Dalton Trans.1983 2131. 328 L. Fabbrizzi H.Cohen and D. Meyerstein 1. Chem. Soc. Dalton Trans. 1983 2125. 329 F. Bottomley Inorg. Chem. 1983 22 2656. 330 A. F. Dyke S. A. R. Knox M. R. Morris and P. J. Naish 1. Chem. SOC.,Dalton Trans. 1983 1417. 33 I A. G. Orpen J. Chem. SOC.,Dalton Trans. 1983 1427. 332 G. K. Yang and R.G. Bergman J. Am. Chem. SOC.,1983 105 6045. Fe Co Ni Table 6 Cluster M2 Fe Fez CO cow Fe3 Fe3 Fe3 Fe3 Fe3 Co3 Fe (c03)2 FeRu Fe,W Few Fe W FeCo c03 c03 NiRu FeRu Fe pt2 CozHg, Fe Rh FeRh, FeRh Fez Rh Ni Nil Ligan ds CO NO RC co RzC CP CO CHCH, Cp CO (CH,),CHMe Cp co RC C6Me6 H CO H MeCO OMe CO CNBu' CO N S CO CMe C=CH, co,sco CO OH PPh3 CO CR Cp co CS, CP co s RC CP CPh Cp CO H RC Cp CO H (Me0)3P PPh, S NO R3 p CO Te Cp co CO PPh s R3P CO H ReJ 3 29 330 33 1 332 333 334 335 336 337 Cp 338 339 340 341 342 343 344 345 346 347 348 349 350 35 1 352 353 354 333 J.A. Abad L. W. Bateman J. C. Jeffrey K. A. Mead H. Razay F. G. A. Stone and P. Woodward J. Chem. SOC.,Dalton Trans. 1983 2075. 334 C. K. Chen and C. H. Cheng Inorg. Chem. 1983 22 3378. 335 W. Wong K. W. Chiu G. Wilkinson A. M. R. Galas M. Thornton-Pett and M. B. Hursthouse J. Chem. SOC.,Dalton Trans. 1983 1557. 336 M. I. Bruce T. W. Hambley and B. K. Nicholson J. Chem. SOC.,Dalton Trans.1983 2385. 337 K. H. Pannell A. J. Mayr and D. VanDerveer J. Am. Chem. SOC.,1983 105 6186. 338 P. Brun G. M. Dawkins M. Green R. M. Mills J.-Y. Salaiun F. G. A. Stone and P. Woodward J. Chem. SOC.,Dalton Trans. 1983 1357. 339 G. Gervais R. Rosetti P. L. Stanghellini and G. Bor J. Chem. SOC.,Dalton Trans. 1983 1613. 340 D. F. Jones P. H. Dixneuf A. Benoit J. LeMarouille Inorg. Chem. 1983 22 29. 34 I L. Busetto J. C. Jeffrey R. M. Mills F. G. A. Stone M. J. Went and P. Woodward J. Chem. Soc. Dalton Trans. 1983 101. 342 L. Busetto M. Monari A. Palazzi V. Albano and F. Demartin J. Chem. SOC.,Dalton Trans. 1983 849. J43 P. T. Cheskey and M. B. Hall Inorg. Chem. 1983 22 2102. 344 K. P. C. Vollhardt and E. C. Walborsky J. Am. Chem. SOC.,1983 105 5507.345 S. Enoki T. Kawamura and T. Yonezawa Inorg. Chem. 1983 22 3821. 346 A. J. Carty N. J. Taylor E. Sappa and A. Tiripicchio Inorg. Chem. 1983 22 1871. 347 H. W. Walker R. G. Pearson and P. C. Ford J. Am. Chem. SOC. 1983 105 1179. 348 A. M. Mazany J. P. Fackler M. K. Gallagher and D. Seyferth Inorg. Chem. 1983 22 2593. 3 49 F. Cecconi C. A. Ghilardi S. Midollini and S. Moneti J. Chem. SOC.,Dalton Trans. 1983 349. 350 D. A. Lesch and T. B. Rauchfuss Znorg. Chem. 1983 22 1854. 351 A. Ceriotti G. Longoni R. D. Pergola B. T. Heaton and D. 0. Smith J. Chem. SOC.,Dalton Trans. 1983 1433. 352 R. J. Haines N. D. C. T. Steen and R. B. English J. Chem. SOC.,Dalton Trans. 1983 1607. 353 F. Cecconi C. A. Ghilardi and S. Midollini Inorg.Chem. 1983 22 3802. 354 A. Ceriotti P. Chini R. D. Pergola and G. Longoni Inorg. Chem. 1983 22 1595.

ISSN:0260-1818    

DOI:10.1039/IC9838000211

出版商:RSC    

年代:1983

数据来源: RSC

摘要:

10 Ru Os Rh Ir Pd Pt By W. LEVASON Department of Chemistry The University Southampton SO9 5NH 1 Ruthenium A major review dealing with catalysis by metal cluster compounds has appeared,' and a second short article' summarizes some recent ideas about the structures and reactivity of clusters. A review3 of electron-transfer processes in d 5 d ions includes data on the Creutz-Taube-type complexes. The potential medical applications of Ru isotopes have been disc~ssed.~ A study of the 99Run.m.r. spectra of a range of ruthenium complexes has demonstrated the potential of this technique and the wide chemical shift range (-9000p.p.m.);5 LRu(CN) was proposed as the "Ru reference to replace RuO used in earlier studies. Investigation of ruthenium carbonyl clusters remains the most active area of research in Ru chemistry with increasing emphasis being placed upon the incorpor- ation of other metal atoms.Conditions for the preparation of the unstable M(CO) compounds (M = Ru or 0s) from M3(C0), and CO have been described.6" The [M(CO),(SbPh,)] (M = Ru or 0s) complexes prepared from them have equatorial SbPh groups,6b in contrast to [M(CO),(EPh,)] (E = P or As) when the Group VB substituent occupies an axial position. The reactions of trans-]( SbF6)2 or ci~-[Ru(C0)~( ](SbF,), [Ru(CO),( Ph2PCH2CH2PPh2) Ph2PCH2PPh2)* with Na[HB(OEt),] produces the corresponding formyls [Ru( HCO)(CO)- (diphosphine),]SbF6 without change in stereochemistry. An X-ray of study of the (deuteriated [Ru( DCO)(CO)(Ph2PCH2CH2PPh2)2]SbF6 revealed a long Ru-CDO bond (2.09 A).7The tran3-[Ru(CO),Cl2(L),1( L = PMe2Ph or AsMe,Ph) compounds react with alkynes RO,CC_CCO,R to give alkenyls [Ru(CO),{C(CO,R)= C(C02R)Cl}CI(L)2],8" and for L = PMe,Ph only with HgR (R = Ph or Me) to give [Ru(CO),R(C~)L~],'~ and cis-or tr~ns-[Ru(PMe~Ph)~(CO)~Cl~] LiR give [Ru(PM~~P~),(CO),R,],~~ which have cis-R groups.' E. L. Muetterties and M. J. Krause Angew. Chem. Int. Ed. Engl. 1983 22 135. M. J. McGlinchey M. Mlekuz P. Bougeard B. G. Sayer A. Marinetti J.-Y. Saillard and G. Jaouen Can. J. Chem. 1983 61 1319. ' C. Creutz Progr. Inorg. Chem. 1983 30,1. S. L. Waters. Coord. Chem. Rev. 1983 52 171. C. Brevard and P. Granger Inorg. Chem. 1983 22 532. ' (a) P. Rubhman ti. N. Van Buuren M. Shiralian and R.K. Pomeroy Organometa//ics 1983 2 693; (b)L. R. Martin F. W. B. Einstein and R. K. Pomeroy Inorg. Chem. 1983 22 1960. ' G. Smith D. J. Cole-Hamilton M. Thornton-Pettit and M. B. Hursthouse J. Chem. Soe. Dalton Trans. 1983 2501. (a) P. R. Holland B. Howard and R. J. Mawby J. Chem. Soc. Dalfon Trans. 1983 231; (b)D. R. Saunders M. Stephenson and R. J. Mawby J. Chem. SOC. Dalton Trans. 1983 2473 245 246 W.Levason The diruthenium complexes (1) (R,R' = H,Me; H,Ph; Ph,Ph) can be protonated to give p-vinyl complexes (2) and these react with H-to give p-carbenes (3)."" On boiling in toluene the complexes (1) (R,R' = H,Ph) are converted into the p-vinylidenes (4) (and the corresponding trans isomers) which can be protonated with HBF4 (R' = H) to the p-ethylidene [Ru~(CO),(~-CO)(~-CM~)(~~-C~H~)JBF~.~~ R' R' I The reactions of (1) with allenes have also been described." Photolysis of [RU~(CO),(~-CO)(~-CHR)(~~-C~H~)~] (R = H Me or C0,Et) in the presence of H2 yields the triruthenium material [RU~(~~-H)~(CO)~(~~-C~H~)~] which reacts with unsaturated hydrocarbons with retention of the Ru unit in contrast to RU,(CO)~ which tends to fragment.'d X-Ray studies of [Ru3(CO) ,{P(cyclo-C,H ,),}I [Ru,(CO),,{P(OMe),),] and [RU~(CO)~(PM~,),]'~" which contain equatorial PR groups and of [Ru3(CO),,-,(CNBu'),,1 (n = 1 or 2) with axial CNR groups,loh and of the produced from RU,(CO)~~ [RU~(CO)~&~-NP~)] and PhNO2,IoC have been reported.A series of Au Ru (n = 1,2 or 3) clusters have been synthesized from AuMe(PPh,) and [Ru3( P-H)~(p3-COMe)( CO),] or [Ru3( p-H)( p-COMe)( CO) ;lad the struc- tures of the Au2Ru3 and Au3Ru3 complexes are shown in (5).The structure of the Hg[Ru3(CO),(C,Bu')] involves Hg bridging one edge of each of the Ru triangles."" The bimetallic [FeRu2(p-C1),(C0),(PR3),] (R = Me or Ph) compounds react with Na2C0 in aqueous acetone to give [F~Ru,(~-OH),(CO),(PR~)~], but in Pr'OH for R = Ph only the product is [F~Ru,(~-OH)(~-H)(CO),(PR~)~].~' (a)A. F. Dyke S. A. R. Knox M. J. Morris and P. J. Naish J. Chem. SOC.,Dalton Trans. 1983 1417; (6) R.E. Colborn D. L. Davies A. F. Dyke A. Endesfelder S. A. R. Knox A. G. Orpen and D. Plaas J. Chem. Soc. Dalton Trans. 1983 2661; (c) R. E. Colborn A. F. Dyke S. A. R. Knox K. A. Mead and P.Woodward J. Chem. SOC.,Dalfon Trans. 1983 2099; (d) N. J. Farrow S. A. R. Knox M. J. Morris and A. G. Orpen J. Chem. Soc, Chem. Commun. 1983 234. lo (a)M. I. Bruce J. G. Matisons B. W. Skelton and A. H. White J. Chem. SOC.,Dalton Trans. 1983 2375; (b)M. I. Bruce j. G. Matisons R. C. Wallis J. M. Patrick B. W. Skelton and A. H. White J. Chem. SOC.,Dalton Trans. 1983 2365; (c) S. Bhaduri K. S. Gopalkrishnan G. M. Sheldrick W. Clegg and D. Stalke J. Chem. SOC.,Dalton Trans. 1983 2339; (d)L. W. Bateman M. Green K. A. Mead R. M. Mills I. D. Salter F. G. A. Stone and P. Woodward J. Chem. SOC.,Dalton Trans. 1983 2599; (e)S. Ermer K. King K. I. Hardcastle E. Rosenberg A. M. M. Lanfredi A. Tiripicchio and M. T. Camellini Znorg. Chem. 1983 22 1339." D. F. Jones P. H. Dixneuf A. Benoit and J.-Y. Le Marouille Inorg. Chem.. 1983 22 29. Ru Os,Rh Ir Pd Pt PPh3 Ph,PAu-Au PPh C OMe OMe (5) The reaction'2n of (PPN)N3 [PPN = bis(triphenylphosphine)iminium] with RU,(CO),~ gives the cyanate [PPN][Ru,(NCO)(CO),,] which takes up H2 to form [Ru,(H)~(NCO)(CO),~]- the latter being protonated by CF3S03H to [H3Ru4(NCO)(C0),2] (6). Unexpectedly [Ru,(NCO)(CO),,]- on reaction with KOH 0 C and PPN+ in MeOH gave [PPN][Ru,H(CO),,] which contains a distorted tetrahe- dral Ru4 core with three terminal CO ligands per Ru and one edge-bridging CO.lZb A combined X-ray and neutron diffraction study of [Ru,(CO)~( p-H)4{P(OMe)3}4] showed an Ru4 tetrahedron each Ru carried -(CO),[P(OMe),] and involved in two symmetrical Ru-H-Ru bridges.I2' The capped butterfly clustei [Ru4(p-H),(CO),,( p4-N)] has been obtained from [Ru,H~(CO),~]- and NOBF in CH2C12.12dReaction of [Ru4( p-H)2(CO)12]2- with MX(PPh3) (M = Cu,Ag or Au; X = C1) gave the hexanuclear clusters [MM'Ru4( p3-H)2(CO),2(PPh3)2] (M = M' = Cu Ag or Au; M = Cu M' = Ag or Au; M = Ag M' = Au) which contain Ru tetrahedra bicapped by MPPh3.12e Among the most interesting aspects of carbonyl chemistry described this year is the synthesis and reactions of the Ru carbido cluster RU~C(CO)~,.'~"-~ The 'parent' RuSC(CO), is produced [along with Ru(CO),] from Ru,C(CO), and CO at 70 "C and 80atm and has been shown to be a square-based pyramid with an exposed carbido atom lying slightly below the basal plane.It undergoes substitution reactions with phosphines to give [Ru,C(CO),,-,(PR,),] (R = MePh2 or Ph,; x = 1,2 or 3) and Ru,C(CO),~[P~~P(CH~)~PP~~] which have similar structures to the parent but adds MeCN to give [Ru,C(CO),,MeCN] in which the metal framework has re- arranged to a bridged butterfly. With X-anions (X = F C1 Br or I) it gives '' (a) D. E. Fjare J. A. Jensen and W. L. Gladfelter Inorg. Chem. 1983 22 1774; (b)J. A. Jensen D. E. Fjare and W. L. Gladfelter Inorg. Chem. 1983,22 1250; (c)A. G. Orpen and R. K. McMullan J. Chem. SOC.,Dalton Trans. 1983 463; (d)M. A. Collins B. F. G. Johnson J. Lewis J. M. Mace J. Morris M. McPartlin W. J. H. Nelson J. Puga. and P. R. Raithby J. Chem. SOC.,Chem. Commun. 1983,689; (e)M. J. Freeman M. Green A.G. Orpen I. D. Salter and F. G. A. Stone J. Chem. SOC.,Chem. Commun. 1983. 1332. 248 W.Levason [Ru,C(CO),~X]- which can be protonated reversibly to [RU~(H)C(CO)~~X].'~" Under pressure Ru,C(CO), will reversibly add CO to give RU&(CO)~, and can be electrochemically or chemically (e.g. KOH-MeOH) reduced 13b to [RU~C(CO),~]~-. The reactions of RLI~C(CO),~ with Au(PPh3)X (X = C1 or Br) give Ru-Au clusters 13' e.g. (7) and (8). Other Ru5 clusters described are [RU5(C0)16(p-PPh2)- (p5-P)]produced by heating [RU,(CO),(~-PP~~)(~-H)],I~~ and [RU~(CO)~~(~~-~)~- CCPh)(p- PPh,)] produced by pyrolysis of the phosphinoacetylene complex [RU~(CO),,(P~,PC&CP~)].'~~ Ru(1 Ru(5A) n Systematic syntheses for the anions [Ru,(CO),~]~- [Ru,(CO) ,I2- [Ru,(CO),~]~-and [Ru,(CO)~~]~- and controlled amounts of M+(benzophenone)-, from Ru~(CO)~~ and for the conjugate acids have been reported,15" whilst under different conditions the rare highly anionic clusters [Ru,(CO) [RU,(CO)~~]~- and [RU,(CO)~~]~- [Ru,(CO),~]~-are pr0d~ced.l~~ The anchoring of a variety of Ru3 Ru, Rug and Ru clusters uia Ph2PCH2CH2Si(OEt)3,16" and of the phosphinidene cluster [(p-H),Ru3(CO),(p3 -PCH2CH2Si(OEt)3],16bto oxide supports has been described.The latter complex shows unusual stability under catalytic conditions. The structures of [(r) -C5 H 5) Ru( CO) Br] and [(7 -C Me,Et) Ru(CO) Br] have been determined and compared in an attempt to correlate structural and reactivity difference^,'^ but it appears that data on other examples will be needed before this l3 (a) B.F. G. Johnson J. Lewis J. N. Nicholls J. Puga P. R.Raithby M. J. Rosales M. McPartlin and W. Clegg J. Chem. SOC.,Dalton Trans. 1983 277; (6) B. F. G. Johnson J. Lewis W. J. H. Nelson J. N. Nicholls J. Puga P. R. Raithby M. J. Rosales M. Schroder and M. D. Vargas J. Chem. SOC.,Dalton Trans. 1983 2447; (c) B. F. G. Johnson J. Lewis J. N. Nicholls J. Puga and K. H. Whitmire 1.Chem. SOC.,Dalion Trans. 1983 787; (d)A. G. Cowie B. F. G. Johnson J. Lewis J. N. Nicholls P. R. Raithby and M. J. Rosales J. Chem. SOC.,Dalton Trans. 1983 23 11. l4 (a) S. A. McLaughlin N. J. Taylor and A. J. Carty Inorg. Chem. 1983 22 1409; (b)S. A. McLaughlin N. J. Taylor and A. J. Carty Organornerallics 1983 2 1194. Is (a)A.A. Bhattacharyya C. C. Nagel and S. G. Shore Organomefallics 1983 2 1187; (b)A. A. Bhattacharyya and S. G. Shore Organomefallics 1983 2 1251. l6 (a) J. Evans and B. P. Gracey J. Chem. SOC.,Chem. Commun. 1983 247 (6) S. L. Cook and J. Evans J. Chem. SOC.,Chem. Commun. 1983 713. H. Adarns N. A. Bailey and C. White Inorg. Chem. 1983 22 1155. 249 Ru,Os Rh Ir Pd Pt is possible. Reduction of [(T~-C,H,)RU(PP~~)~C~] with LiA1H4 produced"" the thermally stable Ru'" hydride [(q 5-C5H5)RuH3] but the corresponding reactions with [(~s-CsH,)Ru(triphos)]+ [triphos = MeC(CH,PPh,),,PhP(CH,CH,PPh,),] resulted in regioselective reduction of the q5-C5H group to an q4-C5H6 ring.'8b Air-stable yellow crystals of the open-chain metallocenes [Ru(pentadienyl),] (pentadienyl = 2,4-dimethyl or 1,2,3,4-tetrarnethylpentadienyl)have been obtained from RuCI3.3H20 zinc dust and the pentadienes.I8" The structure of [Ru(q4-C8Hlo)( ~~-c8H,,)(P(oMe),}] (9) has been determined.'8d The reaction of [RuH,(PP~,)~]with [p-MeOC6H4N=CH-I2 produces air-sensitive black crystals formulated [Ru0(di-imine),J in which the ligands are a-bonded to the Ru via the nitrogen atoms.j9 The [{Ru(arene)X,},] react with MeC02H or CF3C02H to give [RU(~~- arene)X(02CR)] and [Ru( ~~-arene)(O~CR)~] (arene = C6H6 p-MeC,H,CHMe, 1,3,5-Me3C6H etc.).20The dicarboxylates appear to contain one mono- and one bi-dentate 0,CR- group which are equivalent on the n.m.r.time scale and from which the carboxylates are displaced easily by many ligands making these complexes useful precursors.A high spin [Ru"'(NO)CI,]- ion was reported last year but an electrochemical study of the oxidation of [Ru(NO)C15]'- has shown that the [Ru"'(NO)Cls]-ion produced is deep-green and low spin and indicates that the earlier report is in error.''" Sulphite adds to tran~-[Ru(py),Cl(NO)]~+ or cis-[R~(bipy)~X(NO)l"(X = C1 or Br) to give dark green [Ru(py),CI(NOSO,)] and [R~(bipy)~X(NOS0,)1, shown by an X-ray study to contain the new nitrosylsulphito anion [ONSO,]- bonded to the metal uia the nitrogen. The reactions are reversed by aqueous acid.,' Polypyridyl complexes of Ru remain of great interest. The absorption spectrum of the excited state of [Ru(bipy),]'+ (formulated [Ru(bipy);]'+) has been recorded and the promoted electron (M -* L) is localized on one bipyridyl ligand '* (a)S.G. Davies S. D. Moon and S. J. Simpson J. Chem. Soc. Chem. Commun. 1983 1278; (b)S. G. Davies S. J. Simpson H. Felkin and T. Fillebeen-khan Organometallics 1983 2 539; (c) L. Stahl and R. D. Ernst Organometallics 1983 2 1229; (d)P. Pertici G. Vitulli W. Porzio M. Zocchi P. 1.. Barli and G. Deganello J. Chem. SOC Dalton Trans. 1983 1553. 19 B. Chaudret C. Cayret H. Koster and R. Poilblanc J. Chem. Soc. Dalton Trans. 1983 941. 20 D. A. Tocher R. 0. Gould T. A. Stephenson M. A. Bennett J. P. Ennett T. W. Matheson L. Sawyer and V. K. Shah J. Chem. SOC.,Dalton Trans. 1983 1571. 2' (a)V. T. Coombe G. A. Heath T. A. Stephenson and D. A. Tocher J. Chern. SOC.,Chem. Commun. 1983 303; (b)F. Bottomley W.V. F. Brooks D. E. Paez P. S. White and M. Mukaida J. Chem. SOC. Dalton Trans. 1983 2465. 250 W.Levason [Ru"'(bipy),( bipy-)I3+ not delocalized over all three as originally thought.22n Other studies have described the photochemistry of ~is-[Ru(bipy),L,]~+ (L = 4bipy,iphen py pyridazine PMe,Ph etc.),22hand the redox chemistry electronic absorption and emission spectra of [R~(bipy),L,_,,]~~ (n = 0-2; L = 2,2'-bipyrazine or 2,2'-bipyrimidine).22' Polypyridyl complexes of Ru" and 0s" have been electropolymer- ized to produce polymer film coatings on the electrodes.22d7e The arylazopyridines (10) form [RuL,CI2] complexes which can be isolated in two isomeric forms (1 I). These Ru" complexes can be electrochemically oxidized to Ru'" and are converted into [Ru(H?O),L~]~+ by Ag' in water,23a the reaction being reversed by NaCl in both cases without isomerization.Water is dis- placed easily from the aquo complexes to give [Ru1IL,L;In+ (L = bipy en acac or triazine N-oxides)., Arylazo-oximate complexes [Ru(bipy),A]+ (HA = q N=N w (10) (R = Me or H) RC(NOH)N=NR; R = Me Ph or p-MeC&; R' = Ph or p-MeC,H,] have been prepared from [Ru(bipy),Cl( NO)],+ and alkylidene arylhydrazones RCH=NNHR in MeOH in the presence of NaOMe or directly from cis-[Ru(bipy),Cl,] + Na[A].23" Treatment with HClO gives [Ru(bipy),( HA)](ClO,),. Direct reaction of RuCl with HA in ethanol produces cis-[R~(HA),C1,1;~~~ an X-ray study of the (a-phenyl- azo)benzaldoxime complex confirmed the structure to be (1 2).Triazine oxides Rh(O)=NNHC,H,X-p(HL) (R = Et or Ph; X = Me H C1 NO2 etc.) form green- ish-yellow Ru"' complexes [RuL,] (rner-N303 co-ordination) on reaction with RuC13.3H20 and K2C03 in ethanol;23e electrochemical reduction to Ru" and oxidation to Ru'" is possible. The [R~(bipy),L](ClO,)~ complexes are readily reduced to Ru" and two further one-electron reductions probably localized on the bipy (L ligands were observed.23f Air oxidation of [{ Ru"(NH~)~}~L]~+ = meso-4,5-bis(4-pyridyl)-2,2-dimethyl-1,3-dioxolane) produces the Ru"' analogue and hydrogen peroxide., Trifluoroacetamide CF3CONH2 reacts with [Ru,(O,CMe),Cl] to give the RU"~"' complex [Ru,(HNOCCF~),C~].~~ 22 (a)P. S. Braterman A. Harriman G. A. Heath and L. J. Yellowlees J. Chem.Soc. Dalton Trans. 1983 1801 ; (6)J. V. Caspar and T. J. Meyer Inorg. Chem. 1983 22 2444; (c)D. P. Rillema G. Allen T. J. Meyer and D. Conrad Inorg. Chem. 1983 22 1617; (d)C. D. Ellis L. W. Margerum R. W. Murray and T. J. Meyer Inorg. Chem. 1983 22 1283; (e)J. M. Calvert R. H. Schrnehl B. P. Sullivan J. S. Facci T. J. Meyer and R. W. Murray Inorg. Chem. 1983 22 2151. 23 (a)S. Goswami A. R. Chakravarty and A. Chakravorty Inorg. Chem. 1983 22 602; (b)S. Goswami R. Mukherjee and A. Chakravorty Inorg. Chem. 1983,22,2825; (c)A. R. Chakravarty and A. Chakravorty J. Chern. Soc. Dalton Trans. 1983 961; (d)A. R. Chakravarty A. Chakravorty F. A. Cotton L. R. Falvello B. K. Ghosh and M. Tomas Inorg. Chem. 1983,22 1892; (e)R. Mukherjee and A. Chakravorty J. Chem.SOC.,Dalton Trans 1983 955; (-0 1983 2197. 24 D. M. Stanburg D. Gaswick G. M. Brown and H. Taube Inorg. Chem. 1983 22 1975. 25 T. Malinski D. Chang F. N. Feldmann J. L. Bear and K. M. Kadish Inorg. Chem. 1983 22 3225. Ru Os Rh Ir Pd Pt 25 1 Electrochemical oxidation of [Ru"(OEP)(CO)(EtOH)] (H20EP = octaethyl por- phyrin) gives the porphyrin radical compound [Ru"(OEP')+(CO)]+ which forms [Ru"(OEP')(CO)(py)]+ with pyridine but undergoes an Ru -+OEP' electron re- arrangement on treatment with tertiary phosphines to produce [Ru'"(OEP)(PR,),]+.~~ A series of phosphole (L) (13) complexes of Ru" of types cis-and trans-[RuL,(CO),Cl,] and cis-and trans-[RuL,Cl,] have been ~haracterized;,~" the cis-isomers are the more stable thermodynamically.The complex mer-[Ru(L),(CO)Cl,] [L = (13) R = Ph] has been studied by X-ray diffraction. The conversion of cis-and ~~U~~-[RU(M~,PCH,CH~PM~~)~C~~] photochemically into truns-[Ru( Me2PCH2C H2PMe2)2(H20)Cl]f in ethanol and trans-[Ru(Me2PCH,CH2PMe2)z(Me2SO)Cl]+in dimethylsulphoxide has been reported.27b (13) (R= Me Bun But Ph or Bz) X-Ray structures of several Ru" complexes of (f)-o-C6H4( PMePh),( L) have been determined including trans-[RuL2H(CO)]PF6.~Me2C0, cis-[RuL(CO)Cl2(Me2S0)] and trans-[RuL{ (*)-o-C6H4( PMePh)( P(0)MePh)}C12].27c*d The last contains a rare example of a diphosphine monoxide chelating to a metal and was a minor product of the reaction of RuCl with L and HCH0.27d An X-ray study of [(S)-Ru(v5-CSH,)C1(Ph,PCH(R)CH,PPh2)] (R = Me) and some chemistry of the related chiral diphosphine complexes (R = Me cyclo-C6H,, or Ph) has been de~cribed.,~' The Ru" complexes of two triphosphines PhP(CH2CH2CH2PPh,) (ttp) and PhP(CH2CH2CH2P(cyclo-c6Hl,),),(Cyttp) of type [RuLC12] have been prepared,27f the ttp complex is polymeric but the more sterically demanding Cyttp produces a monomeric complex.Both add CO to give monocarbonyls but only [Ru(Cyttp)C12] adds SO2(to form an 7 '-planar adduct) whereas both can be reduced in the presence of CO to [Ruo(CO),L]. Sodium borohydride reduces [Ru(ttp)Cl,], to [RuH(v2- BH,)(ttp)] and this can be converted into various cationic mono and neutral dihydrides by reaction with monodentate P or N donors.27f Ethylenediaminetetra-aceticacid (H,Edta) complexes of Ru" and Ru"' of types [Ru"(H,Edta)L] (L = (p~)~, (4-Mepy), 1,lO-phenanthroline 2,2'-bipyridyl or Ph2PCH2CH2PPh2) and [Ru"'(H,Edta)L'] (L' = (SCN), acetylacetonate- Et2NCS2-) have been prepared and all contain H,Edta as an N202 tetradentate donor.28 The resonance Raman spectrum of [(NH3)5Ru(S2)Ru(NH3)5]4+ is shown 26 M.Barley J. Y. Becker G. Domazetis D. Dolphin and B. R. James Can. J. Chem. 1983 61 2389. 27 (a)L.M. Wilkes J. H. Nelson L. B. McCusker K. Seff and F. Mathey Inorg. Chem. 1983 22 2476; (b) S. F. Clark and J. D. Pedersen Znorg. Chem. 1983 22 620; (c)S. L. Grocott B. W. Skelton and A. H. White Aust. J. Chem. 1983 36 259; (d)S. R. Hall B. W. Skelton and A. H. White Atrst. J. Chem. 1983 36 271 ibid. 1983 36 267; (e)F. Morandini G.Consiglio B. Straub G. Ciani and A. Sironi J. Chem. SOC. Dalton Trans. 1983 2293; (j)J. B. Letts T. J. Mazanec and D. W. Meek Organometallics 1983 2. 695. 2x A. A. Diamantis and J. V. Dubrawski. lnorg. Chem. 1983 22 1983. 252 W Levason to be consistent with the presence of an S$-bridge ruling out the alternative S2-f~rrnulation.~~ undergoes Electrochemical studies have shown that [BU~"N]~[RU~B~,] two reversible one-electron oxidations and one reversible one-electron reduction and [RU~"~'~B~~]~- have been prepared in solution by controlled and [Ru~Vp'VBr9]- ele~trolysis.~~" Molecular orbital (Xa)calculations on the ruthenium chloro-anions [RuCl6I3- [Ru2Cl9I3- and [Ru3C11J4- have been carried out and the results com- pared with structural and spectroscopic data.30b 2 Osmium Two reviews concerned with aspects of catalysis by osmium carbonyl clusters have a~peared.'.~' It has been demonstrated that non-bonded distances can be measured and hence the cluster skeleton identified in [os6(co)],] [OS~(CO)~~]~-, and [OS,~C(CO)~~]~-using EXAFS of the 0sL(II1) edge,32a and similarly the structures of Os3 clusters bound to oxide supports or tethered via bridging ligands to silica can be established.32b Osmium pentacarbonyl is obtained in 60% yield from OS~(CO),~ and CO at 200atm and 280-290 oC.6a Diosmium carbonyls are rare; one example is [OS~(CO)~I~] shown by an X-ray study to be a butterfly structure (14).33A detailed study of the vibrational spectra of the vinyl and vinylidene complexes [OS~(CO),~( pH)(p-q2-CH=CH2)]and [Os,(CO),( P-H)~(p3-q2-C=CH)]andthe 'H analogues identified the characteristic vibrations of the C2-hydrocarbon units 29 S.Kim E. S. Otterbein R. P. Rava S. S. Isied J. San Fillippo jun. and J. V. Waszcyak J. Am. Chem. Soc. 1983 105 336. 30 (a) V. T. Coombe G. A. Heath T. A. Stephenson and D. K. Vattis J. Chem. Soc. Dalton Trans. 1983 2307; (b)B. E. Bursten F. A. Cotton and A. Fong Inorg. Chem. 1983 22 2127. 3' R. A. Adams Acc. Chem. Res. 1983 16 61. 32 (a)S.L. Cook,J. Evans G. N. Greaves B. F. G. Johnson J. Lewis P. R. Raithby P. B. Wells and P. Worthington J. Chem. SOC.,Chem. Commun. 1983 777; (b)S. L. Cook and J. Evans J. Chem. SOC. Chem. Commun. 1983 1287. 33 E. E. Sutton M. L. Niven and J.R. Moss horg. Chim. Acta 1983 70 207. 253 Ru,Os Rh Ir Pd Pt which could be useful in identifying similar species on metal surfaces.34a Heating OS,(CO)~~ with SiHCI3 and CO under pressure results in opening of the Os ring to give the linear-chain compound [C1,SiOs(CO)40s(CO)40s(CO)4SiC13], whose structure can be compared with that of [OS,(CO)~(~-H)3(SiC13)3] which has an 0s triangle edge-bridging hydrides and one SiCI3 equatorially substituted onto each Arenes (e.g. C6H6 C,H,Me C,H&I) react with [OS,(CO)~~(NCM~)~] under reflux to give aryne complexes e.g. [os3(p-H)2(co)9(c6H4)] (1 5).34' The formal similarity between a hydride ligand and Au(PR,) both of which donate one electron to the cluster framework has prompted the syntheses and studies of Os3-AuPR3 complexes including [Os,(CO),(PPh3){Au(PPh3)}(2-NHC,H,N)] [OS (co)9{ Au( PPh3))(C 2 ph)1,34d [O~,(CO)II {Au(PPh3))NCOI [os3(co)lo-{Au(PE~~)INOI,~"' in [OsdCO) in{Au(PEt,)IJ ( 16) and [OsdCO)i 1 {A~(PEt3)}21,~~' all of which the AuPR group bridges two 0s atoms.The reaction of [W(_CR)- (CO),( q5-C5H5)] with [OS~(~-H),(~-CH~)(CO),~] gave the bimetallic or RU~(CO)~~ clusters [MW2(p3-RC2R)(CO),(~5-C5H5)2] (M = 0s or Ru) which exist in two isomeric forms35a (17). The 0s-Pt cluster [OS,P~(~-H)~(CO)~~{ P(cyclo-C,H 1)3)] is the first cluster which reversibly adds both CO and H2 (separately) the products being the closo-[O~~Pt( p2-H)4(C0)In( PR,)] and the butterfly [Os,Pt( p-H)2(C0)11(PR3)], both of which revert to the starting material in a Nz In MeCN solution [OS~H~(CO)~~]- and NOBF4 afford the butterfly cluster cation [Os4H3(CO),2(NCMe)z]BF4,36 but in CH2C12 the major product is [Os,H,(CO),,(NO)] and a minor product is [OS~(/A-H)(CO)~~(/A~-N)] which is con- verted into [0s4(CO),,(p4-N)]- by N02-.lZd A series of papers has described the synthesis of larger clusters by the condensation of smaller clusters incorporating (a)J.Evans and G. S. McNulty J. Chem. Soc. Dalron Trans. 1983 639; (b)A. C. Willis G. N. Van Buuren R. K. Pomeroy and F. W. B. Einstein Inorg. Chem. 1983 22 1162; (c) R. J. Goudsmit B. F. G. Johnson J. Lewis P. R. Raithby and M. J. Rosales J. Chem. SOC.,Dalton Trans. 1983 2257; (d) K. Burgess B. F. G. Johnson J. Lewis and P. R. Raithby J. Chem. SOC.,Dulron Trans.1983 1661 ;(e) 1983 1179; (f)K. Burgess B. F. G. Johnson D. A. Kaner J. Lewis P. R. Raithby and S. N. A. B. Syed-Mustaffa 1. Chem. SOC.,Chem. Commun. 1983 455. 35 (a)L. Busetto M. Green B. Hessner J. A. K. Howard J. C. Jeffery and F. G. A. Stone J. Chem. SOC. Dalton Trans. 1983 519; (b) L. J. Farrugia M. Green D. R. Hankey A. G. Orpen and F. G. A. Stone J. Chem. SOC.,Chem. Commun. 1983 310. 36 B. F. G. Johnson J. Lewis W. J. H. Nelson J. Puga P. R. Raithby and K. H. Whitmire J. Chem. SOC. Dalron Trans.. 1983 1339. 254 W.Levason bridging sulphide (p3-S) or (p4-S) gro~ps.~~~-~ For example pyrolysis of [H0s3(CO),,(p-SPh)] in CO produces the butterfly [OS,(CO),,(~~-S)~] and the square pyramidal [OS,(CO),,(~~-S)].~~~ [Os,(CO),,(p3-S),] can also be produced by photolysis of [Os,(CO),(p3-S),] + OS(CO),,~~' whilst condensation of [OS3(CO)dP3-S)~I and [O~~(CO),O(NCM~),J yield [0s6(c0),7(~4-s)21 and [o~~(co)~~(~4~s)(~3~s)] (18).37" An analogous approach can yield cluster hydrides e.g.[H20s,(CO),,(p4-S)(p3-S)] (19). or larger clusters e.g. [OS~(CO)~,,(~~-S)~] The [os,c(cO),,] takes up CO under pressure to give [os,c(co)]6] the cluster core undergoing a rearrangement from square pyramidal to a bridged butterfly with the carbide at the centre.'3h Reduction of [Os,C(CO),,] affords the dianion [OS,C(CO),,]~- which retains the basic geometry of the parent and this is protonated by concentrated H2S04to [Os,(C)H,(CO) 4,also generated directly from the neutral carbonyl and dihydrogen at 50 atm and 120 "C.A very unusual p3-0x0 group is ~3~~~)(~~)~g] present in the purple [~~~(~3~~)( produced by bubbling oxygen into a refluxing toluene solution of [os6(c0)20]. It has a raft structure (20) and reacts with P(OMe)3 with loss of the 0x0 bridge to give [Os6(CO)2,-,{P(OMe)3},] (n = High nuclearity clusters have also received considerable attenti~n.~~~-~ 37 (a)R. D. Adams Z. Dawoodi D. F. Foust and B. E. Segmuller J. Am. Cbem. Soc. 1983 105 831 ; (b) R. D. Adams 1. T. Horvath 6. E. Segmuller and Li-Wu Yang Organometallics 1983 2 1301 ;(c) R. D. Adams I. T. Horvath P. Mathur B. E. Segmuller and Li-Wu Yang Organometaflics 1983 2 1078; (d) R. D. Adams I. T. Horvath and Li-Wu Yang J. Am. Chem. SOC.,1983 105 1533; (e)R.D. Adams I. T. Horvath P. Mathur and B. E. Segmuller Organometallics 1983 2 996; (f)R. D. Adams D. E. Foust and P. Mathur Organometallics 1983 2 990; (g)R. D. Adams and Li-Wu Yang J. Am. Chem. SOC.,1983 105 235. 38 (a)R. J. Goudsmit B. F. G. Johnson J. Lewis P. R. Raithby and K. H. Whitmire J. Cbern. SOC.,Chem. Commun. 1983 246; (b) B. F. G. Johnson J. Lewis W. J. H. Nelson P. R. Raithby and M. D. Vargas J. Chem. SOC.,Chem. Commun. 1983,608; (c)B. F. G. Johnson J. Lewis M. McPartlin. W. S. H. Nelson P. R. Raithby A. Sironi and M. D. Vargas J. Chem. SOC.,Chem. Commun. 1983 1476; (d) D. Braga J. Lewis B. F. G. Johnson M. McPartlin W. J. H. Nelson and M. D. Vargas,J. Cbern.SOC.,Chem. Commun. 1983,241; (e)D. Braga K. Henrick B. F. G. Johnson J.Lewis M. McPartlin W. J. H. Nelson A. Sironi and M. D. Vargas J. Cbem. SOC.,Cbem. Commun. 1983 1131. RIA,Os Rh Ir Pd Pt The bicapped octahedron [OS,(CO)~~]’-rearranges into [OS,(CO)~~(AUPP~,)~] (21) on reaction with [Au(PPh,)Cl] which could be described as an Os octahedron edge-bridged by two more osmium atoms to produce a pseudo Os butterfly with AuPPh capping the open sides of the The first Os clusters [Os,(CO),,(CHC(R)CH)]-(R = Me or Et) with the core shown in (22) are generated in very poor yield by heating OS~(CO),~ in Bu’OH (R = Me) or 2-methylbutan-1-01 (R = Et),38‘ and [OS,~(CO)~~C]’-, the first Osl, is produced along with smaller clusters by pyrolysis of OS,(CO)~~. Disorder has prevented X-ray identification of the light atom positions but reaction with [Cu(NCMe),]+ gave [Os,IC(C0)27Cu(NCMe)]-,which has the geometry shown in (23) with the carbido atom in a trigonal prismatic cavity.38eThe compound [OS~~H~(CO)~~]~-, the first non-carbido Os, cluster,38d is produced by pyrolysis of [HOs3(CO),,C1] or [OS,(CO),,(OE~)~] suggest-in Bu’OH,and has a similar structure to [OS~~C(CO)~~]~- ing that the hydrides may be interestitial.Os( 1 I) Os( 10) [Os I C(CO)27Cu( NCMe)]- Osmium pentachloride reacts with (NSCl) to form [OSC~~(NSC~)~], which on treatment with [Ph,As]CI is converted into [P~,As][OSC~,(NS)~C~]. The latter has octahedral co-ordination about the Os linear NS groups with the fifth chlorine atom 256 W. Leuason associated with the sulphur possibly di~ordered.~~" Treatment with GaCl gives the neutral thionitrosyl compound.The [Ph,PMe][Os( NO)C14] complex contains a square pyramidal anion with a linear nitrosyl A series of di- and tri-thiocarbamate complexes of osmium( 111) have been character- i~ed,~' and the structure of the dithioselenocarbamate complex [0s2(p-SeS2CNMe2)z(SzCNMe2)3]PF6 has been established (24) by an X-ray study. (24) Preliminary data on the osmium 'Creutz-Taube'-type complex [(NH,),O~(pyrazine)Os(NH~),)~+ have been given. The red crystalline OS"-OS''~ complex is produced by Ru" or electrochemical reduction of the OS~~~-OS"' analogue and further reduction to Os"-Os" is possible with Zn/Hg. The mixed valence material is electronically delocalized on the basis of its electronic spe~trum.~' Treatment of trans-[OsO,X,(PR,),] (below see re$ 44) with carboxylic acids under reflux gave the 0stv complexes [OS~(~-O)(~-O,CR)~X,(PR~')~] (R = Me or Et; R3' = Ph3 or Et,Ph; X = C1 or Br).,," An X-ray study of [Os,(p-0)-(p-02CMe),C1,(PPh3),] revealed the sole established example in a diosmium com- plex of a single bent oxygen bridge.An acetate-bridged 0s"' complex with an Os=Os bond [OS~(~-O~CM~)~C~~] is produced from OSCI,~- MeCO,H and (Me2C0)20.42h Exchange with EtC02H or Pr"C02H gives the corresponding [Os2(p-02CR)4C12] (R = Et or Pr") compounds. Various reactions of the acetate-bridged dimer are shown in Figure 1. The [OsvCl,]- anion originally made from OsCl itself has now been prepared more conveniently by chlorination of [NEt,][Os(CO),X,] and its electronic and resonance Raman spectra reported.43 Osmium is often determined colorimetrically using thiourea and an investigation4" of the reaction of OsO with N,N'-diethyl- imidazolidine-2-thione (L) in H20-HC104 has shown that [Osv'02L4](C104)2 and [OS'~L,C~~](C~O~)~ are intermediates in the reduction ; in the latter complex which was shown to have a trans geometry (S4C12 donors) by an X-ray study the chloride ions presumably arise from reduction of the Ci04-.Further details of the osmium(v1) 39 (a) R. Weber U. Muller and K. Dehnicke 2. Anorg. Allg. Chem. 1983 504 13; (b)B. Czeska K. Dehnicke and D. Fenske 2. Naturforsch. Teil B 1983 38 1031. 40 L. J. Maheu G. L. Miessler J. Berry M. Baraw and L. H. Pignolet Inorg.Chem. 1983 22 405. 4' R. H. Magnuson P. A. Lay and H. Taube J. Am. Chem. Soc. 1983 105 2507. 42 (a)J. E. Armstrong W. R. Robinson and R. A. Walton Inorg. Chem. 1983 22 1301 ;(b)T. Behling G. Wilkinson T. A. Stephenson D. A. Tocher M. D. Walkinshaw J. Chern. SOC.,Dalfon Trans. 1983,2109. 43 W. Preetz and M. Bruns 2. Naturforsch. Teil B 1983 38 680. 44 (a)L. Antolini F. Cristiani F. A. Devillanova A. Diaz and G. Verani J. Chern. SOC. Dalton Trans. 1983 1261; (b)J. E. Armstrong and R. A. Walton Inorg. Chem. 1983 22 1545; (c)G.V. Goeden and B. L. Haymore Inorg. Chim. Acta 1983 71 239. Ru Os Rh Ir Pd Pt tr~ns-Os"Cl~(dppe)~ + 2+ os'Vx,2-t OS"'~(O~CR),C~ y//\y (viii) (vii) trans- 0s'~(acac),C1~ trans-O~"(O~CMe)~(Bu'NC)4 trans- Os"( S,C NMe2)2C12 Os'1'(02CMe)2C1(Bu'NC)3 [OS"(N-NN),]~+ Figure 1 Some reactions of Os2(O2CMe),Cl2 (i) HCl HBr (aq); (ii) RC02H; (iii) 2-hydroxy-pyridine ; (iv) 2,2,2-tr~uoroacerumide Vrom butyrute) ; (v) acetylacetone; (vi) Na[S2CNMe,]; (vii) N-N = 2,2'-bipyridyZor 1,lO-phenanthroline; (viii) Bu'NC; (ix) Na + Bu'NC; (x) PMe,; (xi) Ph2P[CH2I2PPh2 complexes truns-[0~O~(PR,)~X~] = Ph3 MePh2 EtPh, or Et2Ph; X = C1 or (R Br) have been These osmyl complexes are diamagnetic light sensitive readily reduced to trans-[OsX,(PR,),] and rner-[OsX3(PR,),] and can be used as starting materials for the preparation of mixed ligand Os'" Os"' or 0s" complexes.3 Rhodium There have been reviews of catalysis by metal cluster compounds,' and of the enantioselective hydrosilation of olefins by rhodium complexes.45 The synthesis properties and structures of rhodium( 11) carb~xylates,~~ and the platinum metal chemistry of Ph2PCH2PPh2 (mostly Rh Pd and have been critically discussed.The [Rh(porphyrin)(CO)Cl] (porphyrin = octaethyl- or tetraphenyl-porphyrin'-) complexes react with CO and KOH to give the formyls [Rh(porphyrin)(CHO)] + C02.48 Interest in rhodium carbonyl clusters continues to grow and considerable progress in the synthesis of heterometallic clusters has been achieved. An approach to electron counting and structure prediction in high nuclearity Rh and pt carbonyls 45 H. Brunner Angew. Chem. In?. Ed. Engl. 1983 22 897. 46 E. B. Boyar and S. D. Robinson Coord. Chem. Rev. 1983 50 109. 47 R.J. Puddephatt Chem. SOC.Rev. 1983 12 99. 48 B. B. Wayland A. Duttaahmed and B. A. Woods J. Chem. SOC.,Chem. Commun. 1983 142. 258 W.Levason using extended Hume-Rothery rules has been de~cribed.~'" The effects of cation CO pressure and temperature upon the thermal synthesis of rhodium clusters has been examined.49b Direct observation of Io3Rh n.m.r. spectra has recently become possible and this technique has been applied to establish the stereochemistries of [Rh4(CO),2-,{P(OPh)3},] (X = l-~).~~' X-Ray structures of the nitrido cluster [N(PPh,),][Rh,N(CO) 5] and of the carbido [N(PPh3),][Rh,,C,(CO)24] have been The former contains a trigonal prism of rhodium atoms with a central nitrogen atom one terminal CO per Rh and none edge-bridging CO's.The carbido cluster prepared from [Rh,C(C0)15]2- and H2S0 in propan-2-01 has the structure shown in (25a); interestingly it is not isostructural with the isoelectronic [RhI2C2(CO),,]. The new [Rhl l(CO)23]3- anion prepared49f by FeCI oxida?ion of [Rh,(co)l,]3- consists of three condensed octahedral units each sharing a triangular face with both of the adjacent octahedra. Variable-temperature multinuclear (13C 13C{103Rh}, 13C{3'P},31P)n.m.r. studies of [Rh9E(C0)21]2- [Rh,,E(C0),,I3- (E = P or As) and [Rh,2Sb(CO)2,]3- show that at high temperatures both the metal poly- hedra and the carbonyl groups are fluxional; whereas at lower temperatures the Rh and Rhln give spectra consistent with the solid structures although the Rhlz complex is fluxional even at -97 eC.49g Bimetallic Rh-Fe clusters [Fe,Rh(CO),]- 4Y (a)B.K. Teo J. Chem. SOC. Chem. Commun. 1983 1362; (b)J. L. Vidal and R. C. Schoening J. Orgunomeral. Chem. 1983 241 395; (c) B. T. Heaton L. Strona R. D. Pergola L. Garlaschelli U. Sartorelli and I. H. Sadler J. Chem. SOC.,Dalton Truns. 1983 173; (d)R. Bonfichi G. Ciani A. Sironi and S. Martinengo J. Chem. SOC.,Dulfon Trans. 1983 253; (e)V. G. Albano D. Braga P. Chini D. Strumolo and S. Martinengo J. Chem. SOC.,Dalton Trans. 1983 249; (f)A. Fumagalli S. Martinengo G. Ciani and A. Sironi J. Chem. Soc. Chem. Commun. 1983 453; (g)B. T. Heaton L. Strona R. D. Pergolla J. L. Vidal and R. C. Schoening J. Chem. SOC. Dalton Trans. 1983 1941. 259 iiu 29 Rh Ir Pd Pt [FeRk4(C0)15]2- [Fe2Rh,(C0)16]2- (2 isomers) and [FeRh5(CO)16]- have been prepared by reaction of various iron carbonyl anions with [Rh,(CO),,] [Rh(CO),CI], or RhC13.50U The trigonal prismatic cluster [Rh,C(CO)I,]2- adds M(PEt,)+ to give (PEt,)M[Rh,C(CO),,]-(M = Ag or Au) whilst AgBF in acetone gives a series of compounds [Ag,,{Rh6C(CO),5}2]'4-"-(n (n = 1 or 3) [Ag,{Rh,C(C0),5},]'6-'1'-= 2 or 4) in which the Ag atoms cap trigonal faces of the Rh units."' Controlled pyrolysis of [PtRh,(CO),,]- gives [Pt2Rh l(CO)24]3- and [PtRh,2(C0)24]4- the latter containing a 'twinned' cubo-octahedron of Rh atoms with a central Pt the former being similar with the second Pt disordered on the surface.soc The reaction of [Rh(CO),CI] with PPh2H in benzene (1 :4 ratio) gives [Rh(CO)CI(PPh,H),] and in 1 :2 ratio [Rh,(p-PPh,),(p-CI),(p-CO)(CO)3].5'" The latter contains a triangular Rh unit and is readily converted into [Rh3(p-PPh,),(CO),] by NEt2H and CO.When [{Rh( q3-C3H5),Cl},] and [Fe(CO),PPh,H] react in ROH in the presence of CO the product is [RhzFe2(p-PPh2)4(p-CO)2(C0)6] which unusually contains a linear Fe-Rh-Rh-Fe skeleton with single PPh and CO groups bridging the Fe-Rh bonds and two -PPh2 bridging the Rh-Rh When LiPBu' and [Rh(CO),CI] react in THF the product is trimeric [Rh(p- PBu',)CO] which contains a Rh triangular unit with edge-bridging phos- phido groups.51c The [Rh(CO),Cl] has also been encapsulated into a cryptand to give the novel dinuclear complex (25b).51" Phosphido-bridged dimers [M(COD)(p- PPh,)] have been prepared from [M(COD)Cl] (M = Rh or Ir; COD = cyclo-octadiene) and LiPR, and these react with diphosphines (L-L) with stepwise displacement of COD to give [(L-L)Rh(p- PPh,),Rh(COD)] and then [Rh(p-PPh2)(L-L)],.s2" An X-ray study of [Rh(p- PPh2)(Ph2PCH2CH2PPh2)] revealed that the Rh..-Rh separation was 3.47 A too long for a Rh-Rh bond despite the 16e configuration of the rhodium atoms.52h Monodentate phosphines convert [Rh(p-PPh,)(COD)] only into [(PR,),Rh'(p- PPh,)2Rh(COD)] which contain an approximate planar geometry about one Rh (a)A.Ceriotti G. Longoni R. D. Pergolla B. T. Heaton and D. 0. Smith J. Chem. Soc. Dalton Trans. 1983 1433; (b)B. T. Heaton L. Strona S. Martinengo D. Strumolo V. G. Albano and D. Braga J. Chem. SOC.,Dalton Trans. 1983 2175; (c)A.Fumagalli S. Martinengo and G. Ciani J. Chem. SOC. Chem. Commun. 1983 1381. 5' (a)R. J. Haines N. D. C. T. Steen and R. B. English J. Chem. SOC.,Dalron Trans. 1983 2229; (b)R. J. Haines N. D. C. T. Steen and R. B. English J. Chem. Soc. Dalton Trans. 1983 1607; (c)J. L. Atwood W. E. Hunter R. A. Jones and T. C. Wright Inorg. Chem. 1983 22 999; (d)J. P. Lecomte J. M. Lehn D. Parker J. Guilhem and C. Pascard J. Chem. SOC.,Chem. Commun. 1983 296. 260 W.Levason but a distorted tetrahedral one about the other (Rh').52' With dilithium phosphides different products are produced; e.g. [Rh(COD)Cl] and Li2PPh give the phos- phinidene cluster [Rh4(p4- PPh)2(COD)4],52d whilst the bulkier (PBu')~- in the pres- ence of PMe gives [Rh2(p2-PButH),(PMe3),] which contains a Rh=Rh bond the 'extra' hydrogen presumably coming from the solvent (THF).52' Bimetallic materials include [(q5-C5H5)RhFe2Te2(CO)7] produced from Fe,Te2(C0)9 and [(q5-C5H,)Rh(CO),],"" and the unsaturated [CoRh(p-C0)2(C5Me5)2] obtained from [(q5-C5Me5)Rh(C0),] and [CO(C,H~)~(C,M~,)]."~ Irradiation of [Cr(C0),(q6-arene)] and [(q5-C5Me5)Rh(CO),] give [CrRh(p- C0)2(C0)2( q5-CsMe,) (q6-arene)] whereas irradiation of the Rh compound with [Cr(CO),(THF)] [Mo(CO),(MeCN)] or [W(CO),(THF)] give for M = Cr Mo or W [MRh2(p-CO)2(CO),(q5-C,Me5)2].53cAn unusual reaction of [(q5-C,Me,)Rh(CO)] with the phospha-alkyne PzCBu' produced the compound (26).53d The reaction of [RhH(L-L),] compounds with CO produced the active catalysts [{Rh(CO)(L-L)}2(p-CO)2] (L-L = Ph2PCH2CH2PPh2 Two or Ph2P(CH2)3PPh2).53e interconvertable forms of [Rh(RNC),Cl] have been prepared from RNC (R = 2,6-dimethyl-4-bromophenyl) and [Rh(COD)Cl], a purple crystalline material con- taining discrete dimers with Rh-Rh interaction and brown-yellow form with 'isolated' metal centres.54 Numerous small molecules add to planar Rh' complexes; among the interesting examples reported this year is [Rh(o-C6H4(AsMe2),),(q1-CO2)C1] one of the few X-ray established examples of q ' -carbon dioxide binding.55" The yellow-phos- phorus adduct [Rh(P4)(PPh,),C1].2CH2Cl2 was reported some years ago but has now been characterized by an X-ray study which shows a trigonal bipyramidal Rh environment with q2-P4 ~o-ordination.~~~ In [{ MeC(CH2PPh2)3}Rh(P3S3)].C6H6 produced from P4S3 and [Rh(COD)Cl], the phosphorus sulphide fragment co-ordinates in an 77 manner (P,S).55' 52 (a)P.E. Kreter and D. W. Meek Inorg. Chem. 1983 22 319; (b)w.C. Fulz A. L. Rheingold P. E. Kreter and D. W. Meek Inorg. Chem. 1983 22 860; (c) R. A. Jones N. C. Norman M. H. Seeberger J. L. Atwood and W. E. Hunter Organometallics 1983 2 1629; (d) E. W. Burkhardt W. C. Mercer G. L. Geoffroy A. L. Rheingold and W. C. Fulz J. Chem. SOC. Chem. Commun. 1983 1251. 53 (a) D. A. Lesch and T. B. Rauchfuss Inorg. Chem. 1983 22 1854; (b) M. Green D. R. Hankey J. A. K. Howard P. Louca and F. G. A. Stone J. Chem. SOC.,Chem. Commun. 1983 757; (c)R. D. Barr M. Green K. Marsden F. G. A. Stone and P. Woodward J. Chem. SOC. Dalton Trans.1983 507; (d)G. Becker W. A. Hernann W. Kalcher G. W. Kreichbaum. C. Pahl C. T. Wagner and M. L. Zeigler Angew. Chem. Int. Ed. Engl. 1983,32,413; (e)B. R. James D. Mahajan S. J. Rettig and G. M. Williams Organometallics 1983 2 1452. 54 Y. Yamamoto Y. Wakatsuki and H. Yamazaki Organometallics 1983 2 1604. '' (a)J. L. Calabrese T. Herskovitz and J. B. Kinney J. Am. Chem. Soc. 1983 105 5914; (b) W. E. Lindsell K. J. McCullough and A. J. Welch J. Am. Chem. SOC. 1983 105 4487; (c) M. DiVaira M. Peruzzini and P. Stoppioni J. Chem. SOC.,Chem. Commun. 1983 903. Ru,Os Rh Ir Pd Pt 26 1 The monoquaternized amine-phosphine Ph2PCH2CH2N+Me3N03- (L+N03-) forms water soluble Rh’ complexes [(NBD)RhClL](NO,) and [(NBD)RhL2I3’ (NBD = norbornadiene) which readily take up dihydrogen and are active olefin hydrogenation catalysts in aqueous solution.56 Several groups have studied bidentate ligands whose steric properties favour the bridging of two-metal centres.The unsymmetrical Ph2PCH2AsPh2 reacts with [Rh(CO),Cl] to give the ‘head to tail’ dimer [Rh2(p-P~,PCH,ASP~~)~(CO)~C~~] and with [Rh(CO),Cl,]- to give [Rh,(p-P~,PCH,ASP~~)~(~-CO)(~-C~)(CO)~] which easily loses CO to form the A-frame [Rh,(p-Ph2PCH2AsPh2)2(p-C1)(C0)2].57a The tridentate PhP(CH2PPh2) forms the trirhodium complex (27),”’ whilst 2,5-bis(diphenylphosphino)furan and 2-{bis(diphenylphosphino)methyl}pyridine bridge two rhodium centres without Rh-Rh Heterobimetallic Rh-Pd(Pt) complexes are discussed below (Pd Pt Section). Mononuclear Rh” compounds are rare and usually very unstable.Examples obtained in solution using electrochemical or pulse radiolysis techniques include [Rh(bi~y)~],+ [Rh(bipy),( H20)2]2+,58a and complexes of several macrobicyclic amine~.~” Electronic spectra were recorded and the disproportionation and oxida- tion studied. The oxygenation of solutions of [Rh{P(cyclo-C,H 1)3}2C1] produces a paramagnetic material suggested to be a Rh“superoxide complex on the basis of e.p.r. spectral studies.58‘ Rhodium(I1) carboxylate dimers are well known and a detailed study of their electronic spectra has been published the main band being attributed to a cr +cr* transition of the Rh-Rh unit.58d The i.r. spectrum of [Rh2(02CCF3)4(C0)2] exhibits v(C0) at -7 cm-’ higher than that observed in free carbon monoxide.56 R. T. Smith R. K. Ungar L. J. Sanderson and M. C Baird Organomefalfics,1983 2 1138. 57 (a) P. D. Enlow and C. Woods Organometallics 1983 2 64; (6) M. M. Olrnstead R. R. Guimerans and A. L. Balch Inorg. Chem.. 1983 22 2474 (c)M. P. Anderson C. C. Tso B. M. Mattson and L. H. Pignolet Znorg. Chem. 1983,22,3267;(d)J. M. Brown and L. R. Canning J. Chem. SOC. Chem. Commun. 1983 460. 58 (a) H. A. Schwarz and C. Creutz Inorg. Chem. 1983 22 707; (b)J. MacB. Harrowfield A. J. Herlt P. A. Lay A. M. Sargeson A. M. Bond W. Mulac and J. C. Sullivan J. Am. Chem. SOC.,1983 105 5503; (c) G. Valentini G. Braca G. Sbrana and A. Colligiani Inorg. Chim. Acta 1983 69 215; (d)T. Sova T. Kawamura T.Shida and T. Yonezawa Inorg. Chem. 1983 22 56. 262 W. Leuason Rhodium-103 n.m.r. spectroscopy has been used to identify all ten possible chlorobromorhodates(rII1) [RhC16- Br,,I3- including isomers) in solution.59" The first X-ray structural characterization of [Rh(H20)6J3+ and [IT(H~O)~]~+ has been reported59b in the a-alums CsM(S0J2.12Hz0 (M = Rh or Ir). Both 0-and N-bonded isomers of [Rh(NH3)s{(H2N)2CO}]3+ have been isolated and their intercon- version and hydrolysis as a function of pH ~tudied.'~' In acidic solution the 0-bonded form hydrolyses to [Rh(NH3)s(HzO)]3' and the N-bonded to [Rh(NH3)J3+. The series of o-methoxyphenylstibine complexes with L = (0-MeOC,H,),-, SbPh,, viz. [RhL,Cl,] [IrL,CI,] [PdL,Cl,] and [PtL,Cl,] contain the ligands bonded via antimony only but L = o-MeOC,H,SbMe gave [RhLr3C13](Sb3C13)or [RhL~C13](Sbz0Cl donor set) depending upon the condi- tion~.~~~ The syntheses and structures of two interesting rhodocarboranes have been reported [Rh(PPh3)(C2B9H and [HPPh,][3-PPh,-3,3-Br2-3,l ,2-RhC2B9H ,I the former containing two icosahedral fragments linked symmetrically at three vertices and the latter containing an octahedrally co-ordinated rhodium bonded to two bromines the phosphine and three vertices of the carborane.60n,h The [RhH,(O,COH)( PPr'3)2] reduces PhCECPh to trans-stilbene and is converted into the novel carbonato-bridged dimer (28) [Rh2H2(OzCO)( PhCECPh)( PPri3)3].61a A particularly interesting complex6" is the 14-electron species (29) produced from NaN(SiMe,) or KH and [CIR~H(P(BU')~CH~C~H~CH~PBU'~>~.The complex (29) forms adducts with HZ CO etc. and metallates benzene pentane octane or internally metallates one of the But groups on the phosphine. Pentamethylcyclopentadienylrhodium complexes have been much studied in recent years. The [Rh(~5-C5Me5)C12] can be reduced with Na/Hg in the presence of tertiary phosphines to [Rh(q5-C5Mes)(PR3),] which will oxidatively add many substrates to give [Rh(q5-C5Me5)(PR3)2X]+Y-(e.g. X = H Me MeCO or I; Y = 59 (a) B. E. Mann and C. M. Spencer Inorg. Chim. Acta Lett. 1983 76 L65; (6) R. S. Armstrong J. K. Beattie S. P. Best B. W. Skelton and A. H. White 1. Chem. Soc. Dalton Trans. 1983 1973; (c) N. J. Curtis N. E. Dixon and A. M. Sargeson J.Am. Chem. SOC. 1983 105 5347; (d)S. J. Higgins W. Levason F. P. McCullough and B. Sheikh Inorg. Chim. Acta 1983 71 87. 60 (a)P. E. Behnken C. B. Knobler and M. F. Hawthorne Angew. Chem. Int. Ed. Engl. 1983 22 722; (b) L. Zheng R. T. Baker C. B. Knobler J. A. Walker and M. F. Hawthorne Inorg. Chem. 1983,22,3350. 6' (a)T. Yoshida W. J. Youngs T. Sakaeda T. Ueda S. Otsuka and J. A. Ibers J. Am. Chem. SOC.,1983 105,6273;(b)S. Nemeh C. Jensen E. Binamira-Soriaga and W. C. Kaska Organometallics 1983,2 1442. 263 Ru,Os Rh Ir Pd Pt PF6-).62U The formally Rh'" complex truns-[Rh,( q5-CSMe5),(p-CH2),Me2] reacts stepwise with 1 or Br (X,)to give first of all [Rh2(qS-C5Me5),(p-CH2),X2]with elimination of MeX and then [a2( with production of CH4 q5-C5Me5)2(p-X)2X2] C2H4 and C3&; the coupling of C1 fragments to C2 and C3 is notable in connection with Fischer-Tropsch reactions.62b Reaction of [Rh,( qS-C5Mes),(p-C1),Cl2] with (LiMe) or Al,Me and air oxidation gives both cis-and truns-[Rh2(qS-C5Me,),(p-CH2)2Me2];cis +trans isomerization can be achieved by treatment with A12Me6.62C 4 Iridium The reaction between [IrC1(C0),(MeC6H4NH2-p)] CO zinc and HC(PPh2)3 gave [Ir,(CO),HC(PPh,),] and a complex [1r3(CO),(Ph)(p3- PPh)(p2- Ph2PCH2PPh2)] which results from fragmentation of the tridentate pho~phine.~~" The latter contains an Ir3 triangle capped by PhP one edge-bridging Ph2PCH2PPh2 and the Ph bonded to the third iridium.Phosphido-bridged [Ir(COD)(p- PPh,)] is produced from [Ir(COD)Cl] and LiPPh2,s2n whilst truns-[Ir(CO)(PPh,),Cll and Li[Fe(CO)1PPh2] give [IrFe(p-PPh,)(CO),(PPh,),l (x = 4-6).63b An X-ray structure determination of the complex with x = 5 showed it to be [(PPh,)(CO)3Fe(p-PPh,)Ir(CO)2(PPh3)] with a long Fe-Ir bond (2.96 A) which breaks on reaction with H, with addition adds P4S3 of two hydride ligands to the iridium tr~ns-[Ir(CO)(PPh~)~Cl] to give the green crystalline dimer [{Ir(CO)C1(PPh3)},(p-P4S3),]63'in which the P4S3 units bridge the metal centres each iridium being bound to two bridging and one terminal phosphorus of the P4S3 molecules.Phosphorus trichloride and rrans-[Ir(CO)(PEt,),Cl] produce [Ir(CO)Cl,( PEt3),PC12] which can be chlorine-oxidized to the unusual [Ir(CO)Cl,( PEt3)2PC14] complex formally PV.63d The trans chelating ligand 2,ll -bis(diphenylphosphinomethyl)benzo[clphenanthrene complex [Ir(CO)LCl] gives a mixture of products upon chlorine oxidation but the Ir"' analogue [Ir(CO)LCl,] is obtained cleanly using CuCI,.Both have been studied by X-ray diffraction and the structural differences compared.63e With 2-bis(dipheny1phosphino)methylpyridine C5H4N[CH(PPh2),] (PNP) the dimeric [Ir,(p-CO)(CO),(PNP)2](BF4)2 is formed. The structure of this and the rhodium complex [Rh2(C0),(PNP),](PF6) are compared in (30a) and (30b).'" The 62 (a)B. Klingert and H. Werner Chem. Ber. 1983 116 1450; (b)A. Nutton A. V. de Miguel K. Isobe and P. M. Maitlis J. Chem. SOC.,Chem. Commun. 1983 166; (c) K. Isobe A. V. de Miguel P. M. Bailey S. Okeya and P. M. Maitlis J. Chem. SOC.,Dalton Trans.1983 1441. 63 (a)M. M. Harding B. S. Nichols and A. K. Smith J. Chem. SOC.,Dalton Trans. 1983 1479; (b)D. A. Roberts G. R. Steinmetz M. J. Breen P. M. Shulman E. D. Morrison M. R. Duttara C. W. De Brosee R. R. Whittle and G. L. Geoffroy Organornetallics 1983 2 846; (c)A. Ghilardi S. Midollini and A. Orlandini Angew. Chem. Int. Ed. EngL Suppl. 1983 22 554; (d) E. A. V. Ebsworth N. T. McManus N. J. Pilkington and D. W. Rankin J. Chem. Soc. Chem. Commun. 1983 484; (e) E. Baumgartner F. J. S. Reed L. M. Venanzi F. Bachechi P. Mura and L. Zambonelli Helv. Chim. Acta 1983 66 2572. 264 W.Levason [Ir(d~pe)~E,]+ (dppe = Ph2PCH2CH2PPh2 E = S or Se) can be alkylated by CF3S03Me to give [Ir(d~pe)~(~~-E~Me)]+ compounds which for E = S are potent S atom and Me$+ transfer reagents e.g.with PPh both Ph3PS and Ph,PSMe+ are Conversely64b oxidation with 3-C1C6H4C0,H of [Ir(dppe),S,]+ forms [Ir(dppe),S,O]+ which alkylates at 0 on treatment with MeS03F and subsequent treatment with MeNC gives the sulphenate ester [Ir(dppe),(CNMe)(SOMe)]’+. Selenium adds to Ir(Me,PCH2CH2PMe2)2C1 to give [Ir(Me2PCH,CH2PMe2),- (Se4)]C1 which contains an Se4’-ligand which has a ‘half-chair’ conformation. Reaction of this complex with PPh3 extracts selenium to give the [Ir(Me2PCH2CH2PMe2),(Se2)]C1complex.64c Two interesting iridium nitrosyls have been reported; the [Ir(PPh,),Cl(p- L)(p-No)c~cl](PF,)~ L = 3,6-bis(2’-pyridyl)pyridazene contains the first example of a nitrosyl group bridging two different metals.65“ Treatment of [Ir(NO)(MeCN)3(PPh,)2]2+ with 9,lO-phenan- threnequinone-di-imine (H,L) gives the expected [Ir(NO)(H,L)(PPh,),]’+ complex which in the presence of a weak base (NaHCO,) unexpectedly rearranges into the phosphazene-imido complex (3 1) by transfer of a PPh from iridium to nitrogen.65b (31) A unique Ir-Cu cluster [{(MeC(CH2PPh,),)IrP3}3Cu5Br4]CuBr2 has been isolated from the reaction of [Ir(triphos)P,]’ and CUB^.^'" It consists of a central Cu trigonal bipyramid the lower edges of which are bridged by bromine whilst each upper triangular face is capped by an [Ir(triphos)P,]+ unit.Three tris(2,2’-bipyridyl)iridium(111)complexes are known; one (yellow) is the expected IrN6,+ and a combined X-ray and I3C n.m.r. study has shown the orange form to be [Ir(bipy),(C-N-bipy)I2+ with one 2,2’-bipyridyl ligand co-ordinated via one nitrogen atom and a metallated carbon.The third form obtained from the orange one in acid solution is [Ir(bipy)2(C-N-bipy)(H30)]3+.66a Several macro-cyclic amine complexes of Ir”’ of types cis-[IrLX,]+ (L = 1,4,8,1I-tetra-azacyclotetradecane;X = Cl, Br2 or BrCI) truns-[IrL’X,]+ (L’ = L or 1,4,8,12-tetra-azacyclopentadecane,c-meso or c-ruc-5,5,7,12,12,14- hexamethyl- 1,4,8,11-tetra-azacyclotetradecane,X = C1 or Br) have been prepared from the tetramines and IrX6’- in Extensive studies on secondary phosphite complexes of iridium(rr1) have been reported.66c Treatment of [{IrCl(COD)},] with 64 (a) J. E. Hoots and T. B. Rauchfuss Inorg. Chem. 1983 22 2806; (b)J. E. Hoots T.B. Rauchfuss and S. R. Wilson J. Chem. Soc. Chem. Commun. 1983 1226; (c)A. P. Ginsberg J. H. Osborne and C. R. Sprinkle Inorg. Chem. 1983 22 1781. 6.5 (a)A. Tiripicchio A. M. M. Lanfredi M. Ghedini and F. Neve J. Chem. SOC.,Chem. Commun. 1983 97; (b)P. Dapporto G. Denti G. Dolcetti and M. Ghedini 1. Chem. Soc. Dalton Trans. 1983 779; (c)F. Cecconi C. A. Ghilardi S. Midollini and A. Orlandini Angew. Chem. Int. Ed. Eng!. 1983,22,554. 66 (a) G. Nord A. C. Hazell R. G. Hazell and 0. Farver Inorg. Chem. 1983 22 3429; (b)C. W. Poon T. W. Tang and C. M. Che J. Chem. SOC.,Dalton Trans. 1983 1647; (c)J. A. S. Duncan T. A. Stephenson W. B. Beaulieu and D. M. Roundhill J. Chem. Soc. Dalton Trans. 1983 1755. Ru Os Rh Ir Pd Pt PPh2Cl and water gives [IrHCl(COD){ (PPh,O),H}] from which bidentate ligands L-L (Ph2PCH2CH2PPh2 Ph2AsCH2CH2AsPh2 or PhSCH2CH2SPh) displace the diene to give [IrHCl(L- L){(PPh,O),H}].Fluoroboric acid protonates the diphenylphosphinous acid to give [IrHCl(L-L){PPh,(OH)},]BF, which loses HF to give =BF capped materials also prepared directly from BF3-[IrHCl(L- L)-{(PPh,O),BF,}]. Bimetallic compounds can be obtained by substitution of the phosphinous acid proton by a second metal ion. The synthesis and structures of alkali-metal salts of [IrC16]3- [IrCl,( H20)l2- [~r~r,]~- [1r2c1913- [1rc1,12- [~r~r,]'- and some related hydrates have been re-e~amined.~'".~ Although exchange of BC13 and OsF resulted in the recent discovery of OsCl, attempts to prepare higher halides of iridium from IrF and BCI3 BBr, B13 or CC14 gave only mixed halides such as Ir2F3C16 or Ir2Br4F5.67C The reaction of [IrCl(PPh,),] with arachno-[CB8H 13]-gives several products one of which contains a closo structure [1-PPh3-2 H-2,2-(PPh3)2-2 lO-IrCB8Hg] and the likely route of rearrangement has been discussed.68" trans-[Ir(C0)C1(PPh3),1 and c~~s~-B,,H,,~-in methanol gave the formally Ir"' complex [(MeCO-O)(PPh,)-{ HIrCB,H,(PPh,)}] whose structure can be compared with that of the 'isoelectronic' iso-nidp IrV ,complex (32).The mixed-metal complex [(Me,P),Pt(PPh,)-(Ph2PC,H,)HIrB9Hlo] has also been characterized.68' (Pentamethylcyclopentadieny1)iridium complexes in oxidation states +1-+5 have been reported. For example [(q5-C,Me,)Ir(CO)2] in freon solution under irridation will activate methane giving [(q5-C,Me5)Ir(CO)H(Me)].69"The iridium(rr1) complex [( q5-C5Me5)IrMe2(Me,SO)] will metallate aryl halides and related complexes form- ing [( q5-C,Me5)IrMe(m,p-C6H,X)(Me2SO)] probably via an IrV intermediate the rate of reaction depending upon X in the order I > NO2 > CF3 > BrI> H > OMe > C1 > F.69b An IrV hydride has been isolated and characterized by a single crystal X-ray study at -150 "C; [IrH4(q5-C5Me5)] is formed as colourless crystals on treatment of [(~5-C5Me5)21r2C12(p-Cl)2] with H2 and PF6- and subsequent reaction of the [(q5-C5Me5)Ir(p-H)31r(q5-C5Me5)]PF6 produced with Li[BHEt3].69C Iridium(v) is also formally present in the silyl [(q5-C5Me5)IrH2(SiEt3)C1] produced from [(q5-C,Me5)21r2C12(p-C1)2]and Et3SiH.69d Finally the reaction of benzene 67 (a)J.E. Fergusson and D. A. Rankin Aust. J. Chem. 1983 36 863; (b) D. A. Rankin B. R. Penfold and J. E. Fergusson ibid. 1983 36 871 ;(c) R. C. Burns and T. A. O'Donnell J. Fluorine Chem. 1983 23 I. (a)N. W. Alcock J. G. Taylor and M. G. H. Wallbridge J. Chem. SOC.,Chem. Commun. 1983 1168; (b) J. E. Crook,N. N. Greenwood J. D. Kennedy and W. S. McDonald ibid. 1983 83; (c)J. Bould J. E. Cook,N. N. Greenwood and J. D. Kennedy ibid. 1983 949. 69 (a)J. K. Hoyans A. D. McMaster and W. A. G. Graham J. Am. Chem. SOC. 1983 105 7190; (b)M. Gomez D. J. Robinson and P. M. Maitlis J. Chem. SOC.,Chem. Cornmun. 1983 825; (c)T. M. Gilbert and R.G. Bergman Organometallics 1983,2 1488; (d)M. J. Fernandez and P. M. Maitlis Organometallics 1983 2 164 (e) D. J. Fisher and R. Eisenberg Organomernllics 1983 2 764. 266 W.Levason and carbon monoxide on photolysis in the presence of [IrH,(CO)- (Ph2PCH2CH2PPh2)]produces PhCH0.69' 5 Palladium and Platinum A review of the co-ordination chemistry of Ph2PCHzPPh2 contains descriptions of much Pd and Pt chemistry.47 The physics and chemistry of partially oxidized tetracyanoplatinates have been re~iewed,~' and a short article describes the selective oxidation of olefins catalysed by palladi~m.~' An unusual Pt7 cluster [Pt,(RNC),,] (R = 2,6-Me2C6H3) has been prepared by sodium amalgam reduction of [PtC12(RNC)2].72u Its structure can be described as a Pt trigonal bipyramid with two edge-bridging platinum atoms.The reaction of Pd(02CMe), Ph2PCH2PPh2 CO and CF,C02H produces the [Pd,(p3-CO)-(p2-Ph2PCH2PPh2),I2+ which contains a Pd triangular unit with a capping carbonyl and edge-bridging dipho~phines.~~' PEt3)4] cluster A [Pd4Hg2Br2(C0)4( produced from the reaction of [Pd,(CO),(PEt,),] with 8(a-bromomercury-ethyl)quinoline contains a butterfly Pd4(p2-C0)4(PEt3)4 unit capped by HgBr.72' In contrast the [Pd2M2(q5-C,H,)2(p3-C0)2(p-C0)4(PEt3)2] (M = Cr Mo or W) compounds have coplanar Pd2M2 units and a Pd-Pd bond.72d The reduction of [Pt(CO)X,]-with HC02H and Pr",N in THF gives [Pt2X4(CO)2]2- complexes which have been characterized by 13C and 195Pt n.m.r. studies. Exchange reactions in these compounds to produce mixed-halide complexes have also been e~arnined.~," On reaction with PPh the complex X = Br gives [Pt,Br,(p-CO)(PPh,),] an X-ray study of which showed structure (33) with an unsymmetrical carbonyl bridge.73b A 0 cp '\ / P-Pt-Pt-Br variety of syntheses for [ClPd( p-Ph2PCH2PPh2)2PdC1] includes reduction of [PdC12(Ph2PCH2PPh2)] with Zn dust HC02H or N2H4 reaction of [Pd,C12(q3-allyl),] with the diphosphine or comproportionation of [Pd( PPh3)J [PdC12( PhCN)2] and Ph2PCH2PPh2.73' The reaction of [Pd( PPh3)4] [PtCI2( NCBU~)~] and Ph2PCH2PPh2 gave the heterometallic [ClPd( Ph2PCH2PPh2),PtC1] which adds SO2 CO etc.to give 'A-frames' often rever~ibly.'~' A series of dithiophosphinite-bridged complexes of type [M2( p-SPPh,),L,] {M = Pd or Pt;L = CNMe CNBu' PR, P(OPh), or P(OPh),Ph} have been prepared and shown to have 'head to tail' bridged structures (34).73d 70 J.M. Williams Ado. Inorg. Chern. Radiochem. 1983 26 235. 7' J. E. Backvall Acc. Chem. Rex 1983 16 335. 72 (a) Y. Yamamoto K. Aoki and H. Yamazaki Organornetallics 1983 2 1372; (b) L. Manojlovic-Muir K. W. Muir B. R. Lloyd and R. J. Puddephatt J. Chem. SOC.,Chem. Commun. 1983 1336; (c)E. G. Mednikov V. V. Bashilov V. 1. Sokolov Ya. L. Slovokhotov and Yu T. Struchkov Polyhedron 1983 2 141 ; (d) R. Bender P. Braunstein J.-M. Jud and Y. Dusausoy Inorg. Chem. 1983 22 3394. 73 (a) N. M. Boag P. L. Goggin R. J. Goodfellow and I. R. Herbert J. Chem. Soc. Dalton Trans. 1983 1101 ; (6)R. J. Goodfellow 1.R. Herbert and A. G. Orpen J. Chem. Soc. Chem. Comrnun. 1983 1386; (c) P. G. Pringle and B. L. Shaw J. Chem. SOC. Dalton Trans. 1983 889; (d)8. Messbauer H. Meyer B. Walther M. J. Heeg A. F. M. Maqsudur Rahman and J. P. Oliver Inorg. Chem. 1983 22 272. Ru Os Rh Ir Pd Pt Ph, PLS II L-Pp-Pd-L The addition of SO2 02,or CS2 to [{P(cyclo-C,H ,)3}2Pt] has been studied and the structure of the 1 1 sulphur dioxide adduct established as being of the TI-pyramidal type with the P-E-P = 166".74" The [Pt(PBu',),] is much less reactive than the tricyclohexylphosphine analogue. Palladium(0) phosphine complexes [Pt(PPr',) or 3] and [Pd(PPh,),] add CSSe to form (PR3)2Pd(CSSe) in which the CSSe is q2-co-ordinated via C and Se; replacement of the monodentate phosphines occurs on treatment with o-C,H~(PP~~)~ The reaction of or O-C,H,(CH~PP~~)~.~~~ [Pt(CS2)(Ph2PCH2CH2PPh2)]with,[Pt(q2-C2H4)(PPh3)2] cleaves one C-S bond to -give [(Ph2PCH2C H2PPh2)Pt(p- S)Pt(PPh3)(CS)].74' Sulphur adds to [Pt(PPh3),] to give a mixture of [Pt,(p-S),(PPh,),] and [PtS4(PPh3)2];74d the former can be alkylated at S even by CHICll or CHCl?.[Pt,(p-S),(PPh7),] behaves as a bidentate sulphur donor 'ligand' towards Pd" Ni" Hg" and Au'' as for example in compound (35).74e The X-ray structure of [PtS,(Ph2PCH2CH2PPh2)] has confirmed74f the tetrasulphido(2 -) ring structure originally proposed. The first example of v2-co-ordination by a phospha-alkene P(mesity1) =CPh2 is reported in [Pt{MeC(CH2PPh2)3}{P(mesityl)=CPh,}].In [Pt{P(me~ityl)=CPh,)~] and [Pt{P(mesityl)=CPh,},( PECBU')] however 7 '-co-ordination is present.748 The diarsines Ph2As(CH2),AsPh2 (n = 6-12 or 16) (L-L) form trans-[Pd(L-L)X2] (X = halide) complexes which were shown to be monomers for n = 12 16 with trans chelating diarsines but complexes with the shorter-chain (a) J. M. Ritchey D. C. Moody and R. R. Ryan fnorg. Chem. 1983,22,2276; (b)W. Werner M. Ebner W. Bertleff and U. Schubert Organometallics 1983 2 891; (c) W. M. Hawling A. Walker and M. A. Woitzik J. Chem. SOC.,Chem. Commun. 1983 11; (d)R. R. Gukathason R. H. Morris and A. Walker Can. J. Chem. 1983 61 2490; (e)C. E. Briant T. S. A. Hor N. D. Howells and D. M. P. Mingos J. Chem. Soc. Chem. Cornrnun. 1983 1148; (f)C. E. Briant M.J. Calhorda T. S. Hor N. D. Howells and D. M. P. Mingos J. Chem. SOC.,Dalton Trans. 1983 1325; (g)S. I. Al-Resayes S. I. Klein H. W. Kroto M. F. Meidine and J. F. Nixon J. Cbem. Soc. Chem. Commun. 1983 930. 268 W Levason ligands were too insoluble tor molecular weight mea~urements.'~~ These ligands react with [PtCI4l2- to give cis-[Pt(L-L)X,] and with [Pt(C2H4)C13]- to give trans-[Pt(L-L)X,]; the cis complexes are dimeric with bridging L-L but the trans complexes are monomeric.75b An X-ray structure of the complex [Pd3(PhzPCH2CH2PPh2)3(p-CN)3](C104)3 has shown an unexpected trimeric unit based upon -CN-bridges with the 31P and 13C n.m.r. spectra suggesting a Pd-CN-Pd-NC-Pd-NC sequence rather than the more symmetric arrange- ment.75c Although it has usually been found that nitrogen donor ligands form only four-co-ordinate Pd" complexes the tetramine N(CH2CH2NMe2) has been shown to give [PdLXIY (X = CI Br I or NCS; Y = PF or BPh4) which in solution exhibit an equilibrium between four and five co-ordinate (N3X and N4X) pallad- i~m.~'~ Palladium(11) complexes of macrocyclic tetraphosphines have been ~ynthesized~~ by template routes from Pd" complexes of the di-secondary phosphines MeHP(CH,),PHMe (n = 2 or 3) and dialdehydes or diketones [e.g.(36)]. X-Ray structures of two isomers obtained from acetylacetone and Pd{MeHP(CH2)2PHMe)2C12 were both found to contain the 14-membered ring system (36a) one being the planar [PdL]C12 of the RSSR-ligand the other square pyramidal [PdLCl]CI of the RSRS djastereoisomer.The phosphine But2PCH2CHCH2CH2 (L) reacts with [Pt(PhCN),Cl,] in toluene to give [PtL2C12]( P2C12) which on heating in 2-methoxyethanol undergoes a novel rearrangement of one ligand to form a o-ally1 complex [hCl{But PCH =CH( CH3)k H2}L]. 77 The 'A-frame' platinum(I1) complexes [Pt2(p-Ph2PCH2PPhz)2(p-Y)X2]+ when Y = H are fluxional on the n.m.r. time scale and a possible mechanism for inversion 75 (a)W. E. Hill D. M. A. Minahan and C. A. McAuliffe Inorg. Chem. 1983,22,3382; (b)W. E. Hill D. M. A. Minahan C. A. McAuliffe and K. L. Minten Inorg. Chim. Acta 1983 14 9; (c) J. A. Davies F. R. Hartley S. G Murray and M. A. Pierce-Butler 1. Chem. SOC. Dalton Trans. 1983 1305 (d)S. N. Bhattacharyya and C. V. Senoff Inorg. Chem.1983 22 1607. 76 R. Bartsch S. Hietkamp S. Morton,H. Peters and 0. Stelzer Inorg. Chern 1983 22 3624. 77 W. J. Youngs and J. A. Ibers Organometallics 1983 2 979. 269 Ru,Os Rh Ir Pd PI of the A-frame involving a linear Pt-H-R intermediate has been disc~ssed.~~" Treatment of [Pt(Ph2PCH2PPh,)C1,] with LiCECR (R = Ph p-MeC,H, CH,CH,Ph or C(Me)=CH,) produces the face to face dimers (37a) which react with Ph2PCH2PPh2 to give fluxional mononuclear truns-[Pt(Ph,PCH,PPh,),(C-CR),] with monodentate diph~sphines.~~' The latter can be oxidized or quaternized at the unco-ordinated phosphorus to [Pt(C zCR),( Ph2PCH2P(0)Ph2),] and [Pt(C=CR)2(Ph2PCH2PPh2Me)2]12. Direct reaction of [Pt(Ph2PCH2PPh2),]C12 with LiCrCPh gives [Pt(Ph,PCHPPh,),] as well as the acetylide whilst reaction with Hg(C=CR) gives the bimetallic complexes (37b) also obtained from [Pt(Ph2PCH2PPh2),]C1, Hg(O,CMe), and RCECH.~" It is also possible to deprotonate the methylene bridge in [PtX2(Ph2PCH2PPh2)] with LiN(SiMe3), and then to alkylate with Me1 to give [PtX,(Ph,PCH(Me)PPh,)]; repetition of the process produces [PtX2(Ph,PCMe,PPh,)2].78' The ligand 2-diphenylphosphinopyridine, 2-Ph2PC5H4N (Ph,Ppy) readily bridges two-metal centres to produce binuclear For example reaction of [Pt(Ph,Ppy),Cl,] with [Rh(CO),Cl] gives [Pt(Ph2Ppy),C1][Rh(CO)2C12] which con- tains a cis-planar anion and the cation contains one chelating and one monodentate (P-co-ord) Ph,Ppy and one chloride.On heating in benzene it rearranges into [RhPt(Ph2Ppy),(C0)Cl3] (38) which on chlorine oxidation is converted into '' (a)R.J. Puddephatt K. A. Azam R. H.Hill M. P. Brown C. D. Nelson R. P. Moulding K. R. Seddon and M. C. Grossel 1.Am. Chem. SOC.,1983,105,5642; (b)C. R. Langrick D. M. McEwan P. G. Pringle and B. L. Shaw J. Chem. SOC. Dalton Trans. 1983 2487; (c)S. Al-Jibori and B. L. Shaw Inorg. Chim. Acta 1983 74 235. (a)J. P. Farr M. M. Olmstead F. E. Wood and A. L. Balch J. Am. Chem. Soc. 1983 105 792; (b)J. P. Farr M. M. Olmstead and A. L. Balch Inorg. Chem. 1983 22 1229; (c) J. P. Farr F. E. Wood and A. L. Balch Inorg. Chem. 1983 22 3387; (d)M. M. Olmstead R. R.Guimerans J. P. Farr and A. L. Balch. Inorg. Chim. Acto 1983 75 199. 270 W.Levason [RhPt(Ph2Ppy)2(CO)Cl,1 both chlorines being added to the platin~m.~~" The reac- tions of [Rh(Ph,Ppy),(CO)Cl] with [Pd(COD)Cl,] or of [Pd(Ph,Ppy),CI,] with [FUI(CO)~C~] give [RhPd(Ph,Ppy),(CO)Cl,] and both 'head to head' and 'head to tail' isomers of [RhPd(Ph,Py),(MeCN),Cl,] have been obtained the latter being more stable.79* Palladium(1) or platinum(1) complexes are obtained from [Pt(Ph,Ppy),Cl,] and Pd,(dba) or Pt(dba) (dba = dibenzylidene acetone) viz.[PtPd(Ph,Ppy),CI,] and [Pt2(Ph2Ppy)2C12]79' which exist as 'head to tail' isomers. Both 'head to head' (P on Pt) and 'head to tail' isomers of [PdPt(Ph2Ppy),CI2] have been isolated but the 'head to head' (P on Pd) has not been (39). The . P-N P-N NnP II II II X-Pt-Pd-X X-Pt-Pd-X X-Pt-Pd-X Head to head Head to tail Head to head (P-Pt) (P-N= PhzPpy) (P-Pd) (39) ligand PhP(CH2PPh2) (L) also readily bridges metal for example it binds through the terminal phosphines only in [PdLCI,] which then co-ordinates via the central phosphorus to a second metal e.g.in [Cl,Pd{(Ph2PCH,),PPh}Pd(MeCN)Cl2].Removal of the chlorine from [PtHCI(PBu',),] with AgY (Y = PF, BF, etc,) generates the three-co-ordinate hydrides [PtH(PBu',),]Y which will add small neutral ligands (CO MeCN or NH3) to give [PtHL(PBu',),]Y but on reaction with PBu' or P(cyc10-C,H *), the proton is removed to give [P~(PBU~,)~].~'" Dinuclear hydrides are prepared from 'RH,(PR,),' (itself made in situ from [Pt(COD),] PR, and hydrogen) and [PtH(Me,CO)(PR',),].+ The products [( PR,),Pt(p-H),PtH(PR',),]+(R R' = Et Ph or cyclo-C,H ,) are air have the structure (40a) and interestingly show no evidence of exchange between the terminal and bridging hydrides.Other preparations for [(PEt,),Pt(p- H),PtH(PEt3),]+ include photolysis of [Pt(PEt3),C204] in the presence of hydrogen and reaction of [PtHCl(PEt,),] with NaBH,. Analogues with diphosphine ligands are produced by two routes either from [Pt(dimethylpyrazole),(L-L)] HBF, and subsequent treat- ment with KBH, or from [Pt(L-L)CI,] and AgBF4 in methanol followed by addition of KBH,.80d The products have the structure (40b) (L-L = Ph2PCH2CH2PPh2 10 (a)R. G. Goel and R. C. Srivastava Can. J. Chem. 1983 61 1352; (b)F. Bachechi G. Bracher D. M. Grove B. Kellenberger P. S. Pregosin L. M. Venanzi and L. Zambonelli Inorg. Chem. 1983 22 1031 ; (c) R.S. Paonessa and W. C. Trogler Inorg. Chem. 1983 22 1038; (d)C. 8. Knobler H. D. Kaesz G. Minghetti A. L. Bandini G. Banditelli and F. Bonati Inorg. Chem. 1983 22 2324; (e) G. Minghetti A. L. Bandini G. Bonditelli F. Bonati R. Szostak C. E. Strouse C. B. Knobler and H. D. Kaesz Inorg. Chem. 198.7 22 2332. Ru,Os Rh Ir Pd Pt 27 1 Ph2P(CH2),PPh2 Ph2P(CH2)4PPh2 cis-Ph,PCHCHPPh2) and in marked contrast to those with monodentate phosphines the hydrides are fluxional. Treatment with CO or CNR displaces one hydride bridge to form [(L-L)Pt(p-H)-(~-L)P~(L-L)]+ (L = co or CNR).~~' Crown-ethers form adducts with platinum(I1) amines for example {[Pt(PMe,)- (NH,)Cl,].(dibenzo-18-crown-6)) and {2[Pt(PMe3)(NH,)C12]( 18-crown-6)} both of which have been characterized by X-ray crystallography and in each case the interaction is via bifurcated hydrogen bonds between the amine group and the crown oxygen atoms." The reaction of [Pt,(COD)(PEt,),] with nido-5,6-C2B8H 1z affords [9H-9,9-(Et3P)2-plo,l -H-7,8,9-C2PtB8Hlo] which on heating transforms into [9H-9 10-(Et3P),-7,8,9-C2PtB8H9], both of which have been characterized by X-ray studies.82" The 17-vertex platinaborane [(PhMe2P)4Pt3B,4H ,6] has also been pre- pared.82b The reaction of cis-or trans-[PdR2(PR3),] (R = Me Et or Ph) with R'Li in ether or THF results in stepwise replacement of PR3 by R' with stereochemical retention to afford Li[PdR2R'(PR3)] and Li2[PdR2R'2].83a A rare example of 6-hydrogen abstraction has been observed on refluxing C~~-[P~(PR~)~(CH,C~H~M~),] (R = Et or Ph) in xylene when the benzoplatinacyclopentenes [h(C H2C6H4c H2)(PR3)2] are formed.83b In contrast to the extensive studies of (C5H5)- and (C,Me5)- complexes few pentaphenylcyclopentadienyl complexes are known ; a series [(q5-C5Ph5)-(q3-allyl)Pd] (ally1 = various substituted allyls) have now been prepared from NaC5Ph and [(q3-allyl)PdC1],.83' Treatment of [Pd(q3-allyl)(q5-C,Me5)]with PR3 proceeds stepwise uia [Pd(q3-ally1)(q3-C5Me,)(PR3)] to form [Pd(PR3),(q2-CH2=C5Me4)] containing 1,2,3,4-tetramethyl f~lvalene.~~~ Bis(cyc1open-tadieny1)magnesium reacts with [Pt2(p-CI)2(C2H4)2C12] to give [Pt(q-CzH4)-(q'-C5H5)(q5-C5H5)] the latter containing a Pt-Pt and [Pt2(p-C,oH10)(q5-C5H5)2] bond and coupled CsHs rings (41).83e " H.M.Colquhoun D. F. Lewis J. F. Stoddart and D. J. Williams 1. Chem. SOC. Dalton Trans. 1983,607. 82 (a)G. K. Barker M. Green F. G. A. Stone W. C. Wolsey and A. J. Welch 1. Chem. SOC. Dalton Trans. 1983 2063; (6) M. A. Beckett J. E. Crook N. N. Greenwood and J. D. Kennedy J. Chem. SOC.,Chem. Commun. 1983 1228. 83 (a)H. Nakazawa F. Ozawa and A. Yamamoto Organomerallics 1983 2 241 ; (6) S. D. Chappel and D. J. Cole-Hamilton J. Chem. Soc. Dalron Trans. 1983 1051; (c)J. Powell and N. I. Dowling Organometollics 1983 2 1742; (d)H. Werner G. T. Crisp P. W. Jolly H.-J. Kraus and C. Kruger Organometallics 1983,2 1369; (e) N. M. Boag R. J. Goodfellow M. Green B. Hessner J. A. K. Howard and F. G. A. Stone J. Chem. SOC.,Dalton Trans.. 1983 2585. 272 W.Leuason Binuclear Pt"' compounds have attracted considerable recent work.The [Pt''2(P205H2)4]4- species [P205H2 = diphosphite(2 -)] have been studied in some detail by electronic absorption and emission spectroscopy and by i.r. and Raman and their halogen oxidation to produce [Pt11'2(P205H2)4X2]4- described.84"-' The latter compounds have structure (42) and with X = C1 the L-L L-L = H02POP02H2-, HPOi-elc. (42) Pt-Pt bond is 2.695 A consistent with a single Pt-Pt 0 bond. If a deficit of halogen (Cl Br or I) is used in the oxidation [Pt2(P2O5H2),XI4- compounds with a formal Pt oxidation state of 2.5 are produced and these have anomalous conduction properties along the infinite linear chain [-X-Pt- ~t-],,.~~' Phosphate bridged Pt'" materials [Pt2(HPO4),I2- add heterocyclic amines to form [Pt2(HPO4),L2I2- (L = pyridine 2-Mepy or 3,4-Me,Q) and in an attempt to grow crystals of the pyridine adduct [pyH][Pt,H,PO,)( HP04)3(py)s].H20 was produced and struc- turally ~haracterized.',~ In continuing studies aimed at clarifying the nature and chemistry of platinum blues it has been shown that cis-[Pt(NH,),( H20),I2+ and a-pyridone (C5H4NOH) produce several species on reaction in aqueous solution including c~s-[P~(NH~)~(C~H,NOH),]~+ and 'head to head' and 'head to tail' a-pyridonate bridged [Pt2(NH3)4(C5H4N0)2]2+.The 'head to tail' form has two a-pyridonates bridging cis-Pt(NH3) units (Pt-Pt = 2.898 A) whilst the head to head is dimerized in the crystal via stacking and intercation hydrogen-bonding (43).85a Related a-pyridonate-bridged compounds of Pt" with other amines (e.g.ethy-lenediamine),85b of Rlrl and of partially oxidized [Pt(2.25)] materials have been 85b3c characterized and the relationships between the structures (especially Pt-Pt bond lengths) and spectroscopic properties discussed. A mononuclear Pt'" a-pyridone complex mer-[Pt(NH3)2(C5H4NO)C13]has also been prepared and studied by X-ray diffraction methods.85d Halogen oxidation of the palladium( 11) analogues produces [Pd( L- L)Cl,] (L-L = Me2NCH2CH2NMe2 bipy 1,lO-phenanthroline Ph2PCH2CH2PPh2 Me2PCH2CH2PMe2, o-C,H,(AsMe,), or Ph,AsCH,CH,AsPh,) and [Pd(L-L)Br,] (L-L = Me,PCH,CH,PMe, O-C,H,(ASM~,)~) whilst tr~ns-[Pd(L'-L')~X~]-(C104)2 (L'-L' = o-C6H4( Me2PCH2CH2PMe2 o-C6H,(AsMe2)( PMe,); 04 (a) S.F. Rice and H. B. Gray J. Am. Chem. Soc. 1983 105 4571 ;(b)P. Stein M. K. Dickson and D. M. Roundhill J. Am. Chem. SOC.,1983 105 3489; (c)C.M. Che F. H. Herbstein W. P. Schaefer R. E. Marsh and H. B. Gray J. Am. Chem. Soc. 1983, 105,4604; (d) H. L. Conder F. A. Cotton L. R. Falvello S. Han and R. A. Walton Inorg. Chem. 1983 22 1887. a5 (a)L. S. Hollis and S. J. Lippard J Am. Chem. SOC.,1983 105 3494; (b)L. S. Hollis and S. J. Lippard Inorg. Chem. 1983,22 2600 2605 (c) L. S. Hollis M. M. Roberts and S. J. Lippard Inorg. Chem. 1983 22 3637 (d)L. S. Hollis and S. J. Lippard Inorg. Chem. 1983 22 2708. Ru Os Rh Ir Pd Pt 1*+ 3.129 A I X = C1 or Br) are obtained by HN03-HC104 oxidation. X-Ray structures of [Pd(bipy)Cl,] and [Pd{ O-C~H~(ASM~~)~)~C~~](C~O~)~, the first on PdIV complexes of neutral ligands were also In contrast I2 converts [Pd(L-L)I,] {L-L = cis-Ph,PCH=CHPPh or O-C&(SPh)2} into Pd" polyiodides Pd(L-L)12.12 which contain planar Pd" environments with neighbouring molecules linked Pd- I-1-1--I -Pd by di-iodine.866 Threeofthe possible isomers of[R(NH,)2(OH2)2C12]2+namely trans-cis-cis trans-trans-trans and cis-trans-cis have been separated and characterized by i.r.I5N,and 19'Pt n.m.r. spectroscopy and X-ray cry~tallography.~~" Condensation of [Pt(en),J4' with HCHO and NH or MeNO has produced octahedral substitu- tion-inert Ptlv complexes of several macrobicyclic hexamine~~~~ (44) which have been characterized by X-ray diffraction (44a) and by electronic and n.m.r.spectros- copy. Pulse radiolysis or electrochemical reduction provides evidence for transient Ptl'' complexes. Nitrosation of [Pt(en)(bipy)Cl,]Cl with KN02 in aqueous solution produces [Pt(bipy)(ONNCH2CHzNNO~Cl(N02)].E7c Y NH NH HN (,,CHHN) (NH(N HN) (R=HorMe) NH NHHN (4 R (44) (b) 86 (a)L. R. Gray D. J. Gulliver W. Levason and M. Webster J. Chem. SOC., Dalton Trans. 1983 133; (b)ibid. Inorg. Chem. 1983 22 2362; Acta Crystallogr. 1983. C39 822. 87 (a)R. Kuroda S. Neidle I. M. Ismail and P. J. Sadler Inorg. Chem. 1983 22 3630; (b)H. A. Boucher G.A. Lawrence P. A. Lay A. M. Sargeson A. M. Bond D. F. Sangster and J. C. Sullivan J. Am. Chem. Soc. 1983 105 4652; (c)W. A. Freeman J. Am. Chem. SOC. 1983 105 2725; (d)K.Wieghardt M. Koppen W. Swiridoff and J. Weiss 3. Chem. SOC.,Dalton Trans. 1983 1869. 274 W.Leuason 1,4,7-Triazacyclononane HNCH2CH2NHCH2CH2NHCH2CH2, (L) behaves as a mono- or bi-dentate ligand towards Pt",and as a tridentate ligand towards PtIV for example in [Pt(L)Br,]Br [Pt(L),](CIO,),; the [Pt1v(L)2]4+ ion is formed by bubbling oxygen into a hot aqueous solution of [Ptl'(L)2]2+.X7d A multinuclear ("C 77Se,195Pt)n.m.r. study of [PtMe,X(MeE(CH,),,EMe)] (E = S or Se; X = C1 Br or I; n = 2 or 3) has been reported and correlations between the various chemical shifts and coupling constants are discussed. The 77Se n.m.r. spectra clearly indicate the different invertomers present.88 Mixed-valence and partially oxidized materials continue to attract a growing amount of effort.A preliminary communication has described the synthesis and (L structures of [Pd"LI2+ [Pd1VLC12]2+ and [Pd11L][Pd1VLC12](C104)4 = 1,4,8,11-tetra-azacy~lotetradecane).~~" The long-known Magnus green salt [Pt(NH,),][PtCl,] is converted into a one-dimensional conductor by treatment with HC104 and hydrogen Resonance-Raman spectra have been recorded for [Pt(pn)2][Pt(pn)2X2]Y489e (X = C1 Br or I Y = CIO, pn = 1,2-diaminopropane) and [Pt(dien) I][ Pt(dien) 13]12x9d (dien = diethylenetriamine) along with X-ray structural data on these and on [Pt(tn)2][Pt(tn)2X,]Y2 (Y = ClO or BF,; tn = 1,3-diamin0propane).~~~-' Although the reactions of PtI or H2PtC16 with the appropriate MI (M = Rb Cs or NH,) in water give the expected hexa-iodoplatinates(Iv) M2Pt16,90athe unexpec- ted products from the corresponding reactions using [PtC1,I2- were of type M2[PtI,].2H20 (M = K Rb or NH,) which are linear chain mixed-valence materials and no evidence for crystalline materials containing [PtI,l2- was found.90b Halogens oxidize the dithioacetate compounds [Pt,(MeCS,),] to [Pt1'12(MeCS2)4X2] (45) but with a deficit of iodine the product was [Pt,(MeCS2),I] again an infinite s-s chain mixed-valence materialg0' Other significant developments in 'molecular metal chemistry' include the synthesis of [NH4- Me,12- [Pt(C204)2],90d Pb,K1-,[Pt(CN),].1.5H20 (x -0.77),90' A 73M027[Pt(CN)4]C10 5.3H20 (M = Pb or Ba and A = K M = Ba and A = Rb).90f xn E.W. Abel K. G. Orrell and A.W. G. Platt J. Chem. Soc. Dalfon Trans. 1983 2435. 89 (a)M. Yamashita H. Ito K. Toriumi and T. Ito Inorg. Chem. 1983 22 1566; (b)J.-P. Catinat T. Robert and G. Offergeld J. Chem. SOC.,Chem. Commun. 1983 1312; (c) R. J. H. Clark and M. Kurmoo J. Chem. Soc. Dalton Trans. 1983 761; (d)R. J. H. Clark M. Kurmoo A. M. R. Galas and M. B. Hursthouse J. Chem. SOC.,Dalton Trans. 1983 1583; (e)M. Cannas M. B. Lucchesini and G. Marangiu Acta Crystallogr. 1983 C39 15 14; (f)M. Cannas G. Marongiu K. Martin and H. J. Keller 2.Nalurforsch. Ted B 1983 38 1346. 90 (a)G. Thiele C. Mrozek D. Kammerer and K. Wittman Z Natut$orsch. Ted B 1983 38 905; (b) G. Thiele and K. Wittrnan 2.Anorg. Allg. Chem. 1983 507 183; (c)C. Bellitto A. Flamini L. Gastaldi and L. Scaramuzza Znorg.Chem. 1983 22 444; (d) M. Mizuno A. E. Underhill and K. Carniero J. Chem. SOC.,Dalton Trans. 1983 1771 (e)G. S. V. Coles. A. E. Underhill J. M. Williams and A. J. Schulz ibid 1983 2529; (f)G. S. V. Coles A. E. Underhill and K. Carniero ibrd 1983 141 1.

ISSN:0260-1818    

DOI:10.1039/IC9838000245

出版商:RSC    

年代:1983

数据来源: RSC