CATIONIC GROUP-14 PLATINUM(IV) COMPLEXES

Silver(I) salts abstract halide from [PtClMe(2)(Me(2)SnCl)(bpy-(t)bu(2 ))] = (bpy-(t)bu(2) = 4,4'-di-tert-butyl-2,2'-bipyridyl), [PtBrMe(2)(M e(2)SnBr)(bpy-(t)bu(2))](2) . Me(2)SnBr(2), and [PtXMe(2)(Me(3)Sn)(bpy -(t)bu(2))] (X = Cl, I) to form cationic platinum(IV) complexes. [PtMe (2)(Me(2)SnX)(bpy-(t)bu(2))]Y (X = Cl, Br; Y = BF4, PF6) exists as a 1 :1 electrolyte in CH3CN, probably with solvent coordination to the pla tinum(IV) cation. The crystal structure of [PtMe(2)(Me(2)SnCl)(bpy-(t) bu(2))]BF4 shows a polymeric chain of platinum(IV) cations; the backbo ne is formed by the coordination of the tin-bound chloro group of one complex to the empty coordination site of an adjacent complex. Bond le ngths and angles indicate that the chloro group is largely associated with the tin center, although the tin center displays some stannylene character. VT H-1-NMR studies show that the cationic species studied u ndergo rapid exchange processes in solution. Thus, [PtMe(2)(Me(2)SnCl) (bpy-(t)bu(2))](+) exchanges with [PtClMe(2)(Me(2)SnCl)(bpy-(t)bu(2))] and [PtMe(2)(Me(3)Sn)(bpy-(t)bu(2))](+) undergoes rapid exchange proc esses in the presence of Me(3)SnCl.