Electrochemical oxidation and reduction of binary metal carbonyls in aprotic solvents

Abstract

The electron-transfer reactions of several binary metal carbonyls at a Pt electrode in aprotic solvents have been investigated. In tetrahydrofuran, cathodic reduction of the carbonyls M(CO)_n leads to the anions [M₂(CO)_{2n– 2}]^2–(M = Cr, Mo, W, and Fe) and [M(CO)_n]^–(M = V), while reduction of the binuclear carbonyls M₂(CO)₁₀(M = Mn and Re) gives the anions [M(CO)₅]^–. Of the anodic reactions, of particular interest are the oxidations of Cr(CO)₆ and M₂(CO)₁₀(M = Mn and Re) which, in acetonitrile, produce the cations [Cr(CO)₆]⁺ and [M(CO)₅(NCMe)]⁺ respectively. The mechanisms of these electrode reactions have been studied.