Metal complexes of sulphur ligands. Part 13. Reaction of dichloro-(η-cyclo-octa-1,5-diene)-palladium and -platinum complexes with some sulphur-containing nucleophiles

Abstract

Reaction of [Pd(C8H12)Cl2](C8H12= cyclo-octa-1,5-diene) with equimolar amounts of various alkali-metal dithioacid salts ([S–S–]=[S2NEt2]–, [S2COEt]–, or [S2PMe2]–) gives the chloride-bridged dimers[{PdCl(S–S)}2](1). Metathetical reactions of these give the corresponding [{PdX(S2CNEt2)}2](X = Br– or [SPh]–).· Cleavage of these complexes with Lewis bases gives [PdCl(S–S)L](2: L = PPh3, [S–S–]=[S2CNEt2]–, [S2COEt]–, or [S2PMe2]–; L = AsPh3, SbPh3, or C5H5N, [S–S–]=[S2CNEt2]–), and with M′Cl–HCl, M′[PdCl2(S2CNEt2)](3; M′=[AsPh4]+ or [PPh3(CH2Ph)]+) are formed. Reaction of (1; [S–S]–=[S2CNEt2]–) with Na[S2PMe2]·2H2O gives [Pd(S2CNEt2)(S2PMe2)](4a) which partially disproportionates in solution to [Pd(S2CNEt2)2] and [Pd(S2PMe2)2]. Complex (4a) reacts with PPh3 to give [Pd(PPh3)(S2CNEt2)(S2PMe2)](5a) which possesses bidentate [S2CNEt2]– and unidentate [S2PMe2]– groups. In contrast, reaction of [Pt(C8H12)Cl2] and Na[S2CNEt2]·3H2O (1: 1 mol ratio) gives [{PtCl(S2CNEt2)}2C8H12](6a) which in turn reacts with PPh3, to give [PtCl(PPh3)(S2CNEt2)] and with excess of PPh3, to give [Pt(PPh3)2(S2CNEt2)]Cl·H2O. Reaction of (6a) and Na[S2PMe2]·2H2O gives [Pt(S2CNEt2)(S2PMe2)](4b) which on treatment with PPh3 gives [Pt(PPh3)(S2CNEt2)(S2PMe2)](5b).