SYNTHESIS OF CP-2'TA(SH)H-2 FROM CP-2'TA(=S)H (CP'=ETA(5)-T-BUC5H4) AND ITS APPLICATION IN THE PREPARATION OF NEW HYDROSULFIDO-BRIDGED HETEROBIMETALLIC COMPLEXES

Reaction of Cp-2'Ta(=S)H 2(Cp' = eta(5)-t-BuC5H4) with sodium amalgam in the presence of water results in the formation of a new hydride tan talocene complex Cp-2'Ta(SH)H-2. This complex binds unsaturated fragme nts such as [M'(CO)(5)] (M' = Cr or W) and leads to hydrosulfido-bridg ed heterobimetallic complexes 4. H-1 NMR data of complexes 4 indicate a rapid configuration inversion at the chiral sulfur atom. The crystal structure of the bimetallic compound Cp-2'Ta(H)(2)(mu-SH)W(Co)(5) 4b has been solved. The Ta-W distance of 4.644(1) Angstrom is nonbonding and the su[fur atom occupies the central position in the Cp-2'TaH2S fr amework. Extended Huckel molecular orbital calculations have been perf ormed on metalloligand 3 and on the dinuclear complex 4b. A good relat ionship between the NMR, X-ray, and EHMO results is observed.