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 Ph₂PCCPPh₂ produced the bimetallic complex Pt(C₂O₄-OO)(μ-Ph₂PCCPPh₂)]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-Ph₂PCCPPh₂)]₂ have been determined by X-ray crystallography.