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 [(R2SnE)3], where R = Me, Ph and E = Se, Te, and the new compound [(Me2GeTe)3], react with [PtMe2(bu2bpy)] (bu2bpy = 4,4‘-di-tert-butyl-2,2‘-bipyridine) to give the new organoplatinum(IV) metallacycles [PtMe2(R2SnE)2(bu2bpy)] and [PtMe2(Me2GeTe)2(bu2bpy)], respectively. The tin-containing metallacycles complexes can undergo exchange of either the R2Sn or the E groups by reaction with [(R‘2SnE)3] or [(R2SnE‘)3], respectively, to give the corresponding new metallacycles of general formula [PtMe2(R2SnE−R‘2SnE)(bu2bpy)] or [PtMe2(R2SnE−R2SnE‘)(bu2bpy)]. The isostructural series of complexes [PtMe2(Ph2SnE)2(bu2bpy)] with E = S, Se, and Te have been characterized by X-ray structure determinations. It is shown that 119Sn NMR is a useful method of structure determination for these metallacyclic compounds.