Proton Reduction with a Cobalt-Doped Thiomolybdate Cluster: A Structural and Functional Model of Co-Doped MoS2.

A heterometallic thiomolybdate cluster, Cp*3CoMo2S4 (Cp* = 1,2,3,4,5-pentamethylcyclopentadienide) has been synthesized and identified as a molecular electrocatalyst for proton reduction in dimethylformamide. Compared with its homometallic congener (Cp*3Mo3S4), cobalt incorporation improves activity by lowering the overpotential for proton reduction, consistent with the contrasting catalytic performance of MoS2 and its Co-doped derivative. Isolation of the reduced form of Cp*3CoMo2S4 and subsequent reactivity studies provide insight into the reaction pathway. These findings establish Cp*3CoMo2S4 as a molecular model for extended sulfide materials.