Cationic Group 14−Platinum(IV) Complexes

Abstract

Silver(I) salts abstract halide from [PtClMe2(Me2SnCl)(bpy-tbu2)] (bpy-tbu2 = 4,4‘-di-tert-butyl-2,2‘-bipyridyl), [PtBrMe2(Me2SnBr)(bpy-tbu2)]2·Me2SnBr2, and [PtXMe2(Me3Sn)(bpy-tbu2)] (X = Cl, I) to form cationic platinum(IV) complexes. [PtMe2(Me2SnX)(bpy-tbu2)]Y (X = Cl, Br; Y = BF4, PF6) exists as a 1:1 electrolyte in CH3CN, probably with solvent coordination to the platinum(IV) cation. The crystal structure of [PtMe2(Me2SnCl)(bpy-tbu2)]BF4 shows a polymeric chain of platinum(IV) cations; the backbone is formed by the coordination of the tin-bound chloro group of one complex to the empty coordination site of an adjacent complex. Bond lengths and angles indicate that the chloro group is largely associated with the tin center, although the tin center displays some stannylene character. VT 1H-NMR studies show that the cationic species studied undergo rapid exchange processes in solution. Thus, [PtMe2(Me2SnCl)(bpy-tbu2)]+ exchanges with [PtClMe2(Me2SnCl)(bpy-tbu2)] and [PtMe2(Me3Sn)(bpy-tbu2)]+ undergoes ra...