Metal complexes of sulphur ligands. Part 17. Reaction of palladium(II) and platinum(II) monothiobenzoates with various Lewis bases and further studies on complexes containing related ligands

Abstract

Reaction of palladium(II) acetate with an excess of monothiobenzoic acid in benzene gives [{Pd(SOCPh)₂}_n] formulated as a sulphur-bridged polymer (n 3) on the basis of i.r. and molecular-weight studies. In contrast, various forms of [{Pt(SOCPh)₂}_n] are obtained by reaction of Na₂[PtCl₄] and Na[SOCPh] in ethanolic or aqueous media. All these materials, however, react with an excess of various Lewis bases L or L–L {L = PPh₃, PMePh₂, PMe₂Ph, AsPh₃, SbPh₃, or C₅H₅N; L–L = 2,2′-bipyridyl, Ph₂P[CH₂]_xPPh₂(x= 1 or 2)} to give the neutral monomeric [M(SOCPh)₂L₂] or [M(SOCPh)₂(L–L)] complexes which contain unidentate [SOCPh]^– groups. For L = PMePh₂ or PMe₂Ph, ¹H and ³¹P n.m.r. studies indicate a trans configuration whereas the related [Pd(O₂CMe)₂-(PR₃)₂] complexes have a cis configuration. Unlike related complexes of carboxylate and dithioacidate ligands, no evidence has been found here for either the neutral 1 : 1 or ionic 1 : 2 complexes [{M(SOCPh)₂L}_n] or [M(SOCPh)L₂][SOCPh] respectively.