Electrochemical synthesis and redox properties of a polyruthenocene electrode film

A thin and uniform polyruthenocene film was prepared by electroreduction of [Ru(η⁵-C⁵H⁵)(η⁵-C ₅H₄Cl=CHCHO)] in acetonitrile and its electrochemical properties were investigated by cyclic voltammetry. This film undergoes a moderately reversible oxidation, the mechanism of which is explainable as an ECE reaction with a slow chemical step. The kinetics of the chemical step are first-order to the ruthenocene concentration and depend on both solvent and electrolyte anion. The kinetic constant is higher at larger donor number of solvent, lower viscosity of solvent and/or higher coordinating ability of electrolyte anion, implying the competitive coordination of both solvent and electrolyte anion.