摘要:
                                The equilibrium mixture of Cp*(eta(6)-C(5)Me(4)-CH2)TaH2 and [Cp*2TaH] reacts with elemental sulfur to give Cp*Ta-2(eta(2)-S-2)H (1) and Cp*(eta(6)-C(5)Me(4)CH(2))Ta-(eta(2)-S-2) (2). Irradiation of 2 by sunlight in the presence of sulfur results in sulfur insertion into the Ta-methylene bond to giveCp*(eta(6)-C(5)Me(4)CH(2)S)Ta(eta(2)-S-2) (4). The same reaction in the absence of sulfur produces Cp*(eta(6)-C(5)Me(4)CH(2)S)Ta(=S) (5), in which the Ta(eta(2)-S-2) group is transformed into a Ta=S moiety accompanied by a migratory sulfur insertion into a Ta-C bond. As a byproduct in these reactions, C*Ta-2(=S)SH (3), which is an isomerization product of the always present 1, is formed. These reactions provide a new insight into the uslfur chemistry of metallocenes having a fulvenoid substructure. All products are characterized by means of IR-, H-1-, C-13-NMR spectra.