Sulfur-Bridged Ta–M (M = Mo, Cr) Multinuclear Complexes Bearing a Four-Electron-Reduced Dinitrogen Ligand

Sulfur-bridged Ta2M2 complexes (M = Mo, Cr) containing a four-electron-reduced dinitrogen ligand, [Cp*Ta(μ-SC6H4Me)2M(CO)4]2(μ-η11-N2) (Cp* = η5-C5Me5), were synthesized from the ditantalum complex [Cp*Ta(SC6H4Me)2]2(μ-η11-N2), which was obtained by a one-pot reaction using [Cp*TaCl4], di-p-tolyl disulfide, and KC8 under dinitrogen. Crystal structures of the Ta2 and Ta2M2 complexes revealed the analogy of the Ta–N–N–Ta moieties. This new route demonstrates the stability of the N24– ligand in M–S bond formation reactions, which are applicable to the synthesis of sulfur-bridged complexes bearing reduced dinitrogen species.