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.