Inorgamca Chimrca Acta, 65 (1982) L223-L224 L223 Five-co-ordinate Rhenium Thiolato-complexes: the Preparations and Structures of [ReO(SPh)e]-, [Re- (SPh)3(MeCN)(PPh3)] and [Re(NPPh,)(SPh)a] JONATHAN R. DILWORTH*, BRYAN D. NEAVES ARC Unit of Nrtrogen Flxatlon, Umversity of Sussex, Brighton, EN1 9RQ, U.K JOHN P. HUTCHINSON and JON A. ZUBIETA Chemistry Department, State Universrty of New York at Albany, Albany, N. Y 12222, US A. Received July 1,1982 Although there has been intense recent interest in the chemistry of molybdenum and to some extent, tungsten, with sulphur hgands, elements in Groups V and VII have received scant attention. As part of our studies of the binding characteristics of sulphur- ligated metal ions [l] we have prepared the first examples of rhemum complexes of monodentate throlates. A series of oxo-dithiolato-complexes of technetium and rhenium were described recently PI* The Re(V) oxo-complex [ReOCls(PPh&] reacts in refluxmg methanol with an excess of aryl thiolate anion, to give a clear brownish solution. The com- plexes [Ph,P] [ReO(SAr)4]- (Ar = CsH5, p-MeCsHd, C6Fs, C,Cls) can then be precipitated by the addition of [PhqP] Br. The thiolate amon is generated by addi- tion of triethylamine m an amount equivalent to the thiol. The complexes all show an intense band in the range 950-990 cm-’ assigned to v(Re=O). Conduc- trvity measurements over a range of concentrations and the equivalence of the p-Me groups suggest the anions are monomeric. They are therefore analogous to the molybdenum(V) complexes [MoO(SAr),]- [3], and probably share the same square pyramidal structure with apical oxo-group. The complexes undergo irreversible one electron oxidations and two electron reductions in acetonitrile at a Pt electrode with [Bu4N] [BF,] as support electrolyte. Full details will be reported elsewhere. The complexes [ReO(SAr&,]- react with excess PPhs in refluxing MeCN to give the purple Re(III) complexes [Re(SAr)s(MeCN)(PPhs)] (A). The com- plexes (A) can also be prepared by reaction of [ReCls(MeCN)(PPh,),] with arylthtolate anions. *Author to whom correspondence should be addressed. 0020-1693/82/0000-0000/402.75 c24 C23 c22 Fig. 1. An ORTEP representation of the structure of [Re- SPh)s(MeCN)(PPhs)] showing the atom labellmg scheme. Important bond lengths (A) and angles (“): RE-Sl, 2.248(7); Re-S2, 2.555(6); Re-S3, 2.264(7); Re-Pl, 2.351(6); Re- Nl 2.07(2). Nl-C37, 1.16(3), C37-C38, 1.49(4). Sl-Re- S2, 118.7(3); Sl-Re-S3, 117.2(2); S2-Re-S3, 124.0(2); Sl-Re-Pl, 90.0(2); Sl-Re-Nl, 93.9(6); S2-Re-Pl, 87.4(2); S2-Re-Nl, 89.4(6);S3-Re-Pl, 89.0(2); S3-Re- Nl, 90.6(6). The X-ray crystal structure of the complex [Re- (SPh),(MeCN)(PPh,)] was undertaken, and an ORTEP representation of the structure appears m Fig. 1 with some important bond lengths and angles. The complex consists of discrete monomeric trigonal pyramidally co-ordinated Re atoms. The thiolato- sulphurs occupy the trrgonal plane with the MeCN and PPh3 groups in axial posrtions. An interesting feature of the complex is the disposition of all the thiolato-aryl groups away from the PPh3 group, to provide a molecular cavity containing the MeCN group. These aryl groups provide a steric constraint to the ligands which can occupy the apical site truns to the PPh3 group. Thus small linear molecules such as CO will readily replace the MeCN to give [Re(SPh)3(CO)(PPh3)] (v(C0) = 1962 cm-‘) whereas hgands such as acetylene which bind side-on cannot be accommodated. The nitride-complex [ReNC12(PPh3)2 ] reacts with an excess of arylthiolate anion in acetonitrile under reflux to give a yellow solution from which no well 0 Elsevrer Sequoia/Printed m Switzerland