The electrochemical oxidation of ruthenocene in various room temperature ionic liquids

Abstract

The electrochemical behavior of ruthenocene, RuCp 2, was investigated on both a platinum microdisk electrode and a platinum macroelectrode in six different room temperature ionic liquids of varying viscosity, at a range of temperatures and concentrations. It was observed that the redox behavior of RuCp 2 is not well understood in both aqueous and non-aqueous media. A process involving the one electron oxidation of RuCp 2 to the [RuCp 2] + monocation, followed by dimerization to form the [Cp 2Ru–RuCp 2] 2+ species has been speculated although, chronoamperometry suggests that the oxidation of RuCp 2 proceeds via a two-electron process. For this reason, it is believed that an ECE mechanism proceeds in which the electrogenerated [RuCp 2] + monocation undergoes a nucleophilic reaction with the anions of the ionic liquid media, in a chemical step which facilitates the transfer of a second electron.