Pyrolyses of diaryl(phosphine)platinum(II) complexes: effect of added phosphines
Abstract
The presence of additional tertiary phosphine, L or P–P, promotes the thermal reductive elimination of biaryl, R2, from cis-[PtR2L2] or [PtR2(P–P)](R = Ph or C6H4Me-4; L = PPh3; P–P = Ph2PC2H4PPh2 or Ph2PCH2PPh2). Secondary decomposition modes, which operate in the pyrolysis of the platinum complexes themselves, are largely suppressed, and the primary metal-containing products are [PtL3] or [Pt(P–P)2]. The platinum(O) complexes themselves undergo thermolysis at elevated temperatures, and the products from the chelating phosphine derivatives indicate a reaction route involving insertion of Pt0 into alkyl–phosphorus bonds. There is evidence that in some cases added phosphine exchanges with that already in the complex before thermolysis begins.