Base-promoted synthesis of monometallic and bimetallic platinum complexes containing chelating O,O- or S,S-donor ligands

Dichloroplatinum complexes [PtCl2L2] (L2 = cod, dppp) react with 1,2-C6H4E2 (E = O, S) in the presence of a base to produce mononuclear complexes. The diene was not readily displaced from [Pt(E2C6H4-EE)(cod)]. A second approach to complexes containing dianionic chelating ligands involved [Pt(acac)2] as precursor. Reaction with dppp and oxalic acid gave [Pt(C2O4)(dppp)], whereas the analogous reaction with Ph2PCtriple bond; length of mdashCPPh2 produced the bimetallic complex [Pt(C2O4-OO)(μ-Ph2PCtriple bond; length of mdashCPPh2)]2. Similar reactions with 1,2-C6H4E2 (E = O, S) also gave bimetallic products. The structures of [Pt(C2O4)(dppp)] and [Pt(C2O4-OO)(μ-Ph2PCtriple bond; length of mdashCPPh2)]2 have been determined by X-ray crystallography.