Cyclic voltammetry of silyl- and stannyl-tricobalt cluster compounds

The electrochemical behavior of the clusters PhM′Co₃(CO)_n (M′ = Si, n = 11 and M′ = Sn, n = 12) has been examined via cyclic voltammetry in CH₂Cl₂ solution. In both cases the radical anions PhM′Co₃(CO)_n? are unstable, rearranging to Co(CO)₄ and other products. However, for the silicon compound, where there is one formal cobalt—cobalt bond, the radical anion is sufficiently stable to allow for detection of anion reoxidation at medium scan speeds. The half-life of PhSiCo₃(CO)₁₁? has been calculated as 2.3 s at 25°C.