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(S'Bu), (1), was isolated from the reaction between Cp*WCl4 and four equivalents of LiS'Bu in THF at - 78 degrees C. Degradation of I occurred in solution at room temperature via C-S bond cleaving reactions to generate a complex mixture containing Cp*W(S)(2)(S'Bu) (2), anti-Cp*W-2(2)(S)(2)(mu-S)(2) (3), and syn-Cp*W-2(2)(S)(2)(mu-S)(2) (4). Complex 1 was converted into a thermally stable 'BuNC adduct, Cp*W(S'Bu)(3)(CN'Bu) (5), which was also obtained from the Cp*WCl4/LiS'Bu/CN'Bu reaction system. compounds 1, 4, and 5 have been structurally characterized by X-ray diffraction. (C) 1999 Elsevier Science S.A. All rights reserved.