Oxidative addition of mercury(II) halides and carboxylates to platinum(II): formation of Pt–Hg covalent and donor–acceptor bonds

The complex [PtMe2(bu2bpy)], 1, bu2bpy = 4,4′-di-t-butyl-2,2′-bipyridine reacts with mercury(II) halides HgX2 (X = Cl, Br, O2CCF3, O2CMe) to give the corresponding complexes [PtMe2X(HgX)(bu2bpy)], 2, by trans oxidative addition followed, when X = O2CCF3, O2CMe only, by easy isomerization to the cis isomers 3. The complexes 2 or 3 react with complex 1 to give the corresponding adducts [PtMe2X(bu2bpy)(μ-HgX)PtMe2X(bu2bpy)], 4, which are shown to contain both covalent and donor–acceptor Pt–Hg bonds in the solid state, and which exhibit very easy fluxionality in solution.