Oxidative addition of Ph2TeCl2 to a dimethylplatinum(II) complex: effects of secondary bonding in the platinum-tellurium products.

In the first example of oxidative addition of tellurium-halide bonds to a transition-metal complex, Ph(2)TeCl(2) reacts with [PtMe(2)(bu(2)bpy)], 1, bu(2)bpy = 4,4'-di-tert-butyl-2,2'-bipyridine, to give an organoplatinum(IV) complex that can be formulated as an ionic diphenyl telluride complex [PtClMe(2)(TePh(2))(bu(2)bpy)]Cl or as a neutral chlorodiphenyltelluryl complex [PtClMe(2)(TePh(2)Cl)(bu(2)bpy)]; the complex contains an unusually long Te...Cl bond length of 3.43 A. The weakly bound chloride ligand is easily removed by reaction with AgO(3)SCF(3) to give the cationic complex PtClMe(2)(TePh(2))(bu(2)bpy) in which the triflate anion is not coordinated to tellurium. This complex reacts with a second 1 equiv of AgO(3)SCF(3) to give the aqua complex PtMe(2)(OH(2))(TePh(2)..O(3)SCF(3))(bu(2)bpy), in which a triflate anion forms secondary bonds with both the aqua and TePh(2) ligands. In these platinum(IV) complexes, the magnitude of the coupling constant (1)J(PtTe) is strongly influenced by the presence of the weakly bonded Te...X groups.