Isolation of pentamethylcyclopentadienyl tris(tert-butylthiolato) complexes of tungsten(IV) and carbonsulfur bond activation

A thermally unstable tert-butylthiolato complex of tungsten (IV), Cp*W(StBu)3 (1), was isolated from the reaction between Cp*WCl4 and four equivalents of LiStBu in THF at −78°C. Degradation of 1 occurred in solution at room temperature via CS bond cleaving reactions to generate a complex mixture containing Cp*W(S)2(StBu) (2), anti-Cp*2W2(S)2(μ-S)2 (3), and syn-Cp*2W2(S)2(μ-S)2 (4). Complex 1 was converted into a thermally stable tBuNC adduct, Cp*W(StBu)3(CNtBu) (5), which was also obtained from the Cp*WCl4/LiStBu/CNtBu reaction system. Compounds 1, 4, and 5 have been structurally characterized by X–ray diffraction.