Mechanistic studies of reactions of benzenethiol with methyl derivatives of platinum(II) and gold-(I) and -(III)

Abstract

Benzenethiol reacts with the complexes [MeAuL], [Me₃AuL], and cis-[PtMe₂L₂](L = PMe₃, PMe₂Ph, PMePh₂, or PPh₃) to give methane and [(PhS)AuL], cis-[Me₂Au(SPh)L], and trans-[PtMe(SPh)L₂] or trans-[Pt(SPh)₂L₂] respectively. The reactions with the gold(I) and platinum(II) complexes proceed by free-radical chain mechanisms, but the gold(III) complexes react by a non-radical mechanism. Competitive reactions with benzenethiol show the order of reactivity [MeAu(PMe₃)] > [MeAu(PMePh₂)] > [MeAu(PPh₃)], cis-[PtMe₂(PMe₂Ph)₂] > trans-[PtMe(SPh)(PMe₂Ph)₂][Me₃Au(PMe₃)], [Me₃Au(PMePh₂)]cis-[Me₂Au (SPh)(PMe₃)].