Reaction of CpWOs3(CO)(11)(mu(3)-CTol) with H2S: mu-alkylidene and mu(3)-alkylidyne WOs3 cluster complexes containing a sulfido ligand

Abstract

Initial decarbonylation of CpWOs3(CO)(11)(mu(3)-CTol) (1; Cp = eta(5)-C5H5, Tol=p-C6H4Me) with Me3NO/MeCN followed by a reaction with H2S produces a sulfido-alkylidyne complex as a major product, CpWOs3(CO)(10)(mu(3)-CTol)(mu(3)-S) (2, 48%), and two hydrido-sulfido -alkylidene complexes as minor products, CpWOs3(CO)(10)(mu-CHTol)(mu(3)-S)(mu-H) (3, 12%) and CpWOs3(CO)(9)(mu- CHTol)(mu-S)(mu-H) (4, 14%) by S-H bond activations of H2S. Decarbonylation of 3 with Me3NO/CH2Cl2 affords complex 4 in 67% yield. Compounds 2, 3 and 4 have been isolated as crystalline solids and have been characterized by spectroscopic (IR, MS, H-1 and C-13-NMR) and analytical data. The structures of 2, 3 and 4 have been determined by single-crystal X-ray diffraction studies. Complexes 2 and 3 are based upon a 'butterfly' WOs3 metal core of a 62 valence electron (VE) with a respective dihedral angle of 100.60(7) and 83.82(8)degrees between the W-Os(3)-Os(1) and W-Os(3)-Os(2) planes. Each molecule consists of three Os(CO)(3) units, a CpW(CO) fragment and a triply bridging sulfide ligand across the open Os(1)-W-Os(2) triangular face. The mu(3)-alkylidyne in 2 caps unsymmetrically the outer face of the W-Os(1)-Os(3) 'wing' triangle. For 3, the mu-alkylidene ligand bridges the 'hinge' W-Os(3) bond and the mu-hydride ligand is supposed to span the W-Os(1) linkage. Complex 4 contains a tetrahedral WOs3 core associated with a 60 VE. The mu-sulfido and mu-alkylidene ligands bridge the W-Os(2) and W-Os(1) edges, respectively. The mu-sulfido ligand is involved in a W=S: --> Os bridge (W-S = 2.21(2) and Os(2)-S = 2.47(2) Angstrom). The mu-hydride ligand is believed to span the elongated Os(2)-Os(3) edge. The tolyl substituent on the alkylidene C is oriented away from the mu-sulfido ligand. (C) 1998 Elsevier Science S.A. All rights reserved.