Synthesis of Metallacycles by Oxidative Addition of Sn-S, Sn-Se, Sn-Te, and Ge-Te Containing Precursors to Platinum(II).

The first metallacycles formed by oxidative addition of tin-sulfur, tin-selenium, tin-tellurium, and germanium-tellurium bonds to platinum(II) are reported. In particular, the ring compounds [(R(2)SnE)(3)], where R = Me, Ph and E = Se, Te, and the new compound [(Me(2)GeTe)(3)], react with [PtMe(2)(bu(2)bpy)] (bu(2)bpy = 4,4'-di-tert-butyl-2,2'-bipyridine) to give the new organoplatinum(IV) metallacycles [PtMe(2)(R(2)SnE)(2)(bu(2)bpy)] and [PtMe(2)(Me(2)GeTe)(2)(bu(2)bpy)], respectively. The tin-containing metallacycles complexes can undergo exchange of either the R(2)Sn or the E groups by reaction with [(R'(2)SnE)(3)] or [(R(2)SnE')(3)], respectively, to give the corresponding new metallacycles of general formula [PtMe(2)(R(2)SnE-R'(2)SnE)(bu(2)bpy)] or [PtMe(2)(R(2)SnE-R(2)SnE')(bu(2)bpy)]. The isostructural series of complexes [PtMe(2)(Ph(2)SnE)(2)(bu(2)bpy)] with E = S, Se, and Te have been characterized by X-ray structure determinations. It is shown that (119)Sn NMR is a useful method of structure determination for these metallacyclic compounds.