An Electrochemical Study of Immobilized Ruthenocene in Aqueous Media

The voltammetric exploration of ruthenocene RuCp2 in aqueous solution via abrasive modification on a basal plane pyrolytic graphite electrode is reported. It is found that ruthenocene undergoes a one‐electron electrochemically irreversible oxidation to ruthenocenium, which then rapidly dimerizes to form [RuCp2]$\rm{ {_{2}^{2+}}}$. Then, depending on the anion in solution, either disproportionates to [RuCp2]2+ and subsequently decomposes to ruthenium oxide, or is anion stabilized. SEM images and cyclic voltammetry of the electrode surface indicates that in the presence of smaller anions the dimer is not stabilized, whereas for larger anions, such as sodium toluene sulfonate, the dimer is stabilized and decomposition is inhibited.