Chemistry of the Paramagnetic Co₃(CO)₉(μ₃-S) Cluster. Rational Synthesis of Co₃(CO)₇(μ-X)(μ₃-S) Complexes

Abstract

The paramagnetic Co3(CO)9(μ3−S) cluster (1) reacts with organic compounds containing S−H, S−S, or P−H bonds to give diamagnetic Co3(CO)7(μ-X)(μ3−S) (μ-X = (μ-L, μ-(1,2-η)-L, and μ-(1,3-η)-L) complexes. The reaction was used to prepare the derivatives with μ-L = SR (2a−h; R = Et, t-Bu, CH2Ph, allyl, Ph, C6F5, 2-naphthyl, CH2CH2OH) and PPh2 (7), μ-(1,2-η)-L = P(S)Ph2 (8), and μ-(1,3-η)-L = S2CR (R = SMe (4), OMe (5), Ph (6)). The reaction results in an increase of the oxidation state of cobalt and may be therefore called an oxidative substitution. It is the first successful and rational way to prepare derivatives of Co3(CO)9(μ3-S), a fundamental cluster molecule described in 1961. The crystal structures of the triphenylphosphine-substituted derivative of 2b, Co3(CO)4(PPh3)3(μ-S-t-Bu)(μ3-S) (3), and of 4, 6, and 8 were determined. A new, high-yield synthesis of 1 is described.