Chemically Catalyzed Net Electrochemical Oxidation of Alcohols, Aldehydes, and Unsaturated Hydrocarbons Using the System (trpy)(bpy)Ru(OH2)2+/(trpy)(bpy)RuO2+

Article abstract of DOI:10.1021/ja00527a030

A mild electrocatalytic technique has been developed for the oxidation of selected alcohols, aldehydes, and unsaturated hydrocarbons at 25-50 deg C using as catalyst the systems (bpy)2pyRu(OH2)²⁺/(bpy)2pyRuO²⁺ and (trpy)(bpy)Ru(OH)²⁺/(trpy)(bpy)RuO²⁺.The organic compounds were dissolved or dispersed in an aqueous buffer solution of the catalyst, and the net oxidation were carried out using conventional three-electrode electrolysis cells at applied potentials which were sufficient to cause the oxidation of Ru(II) to Ru(IV) (0.6-9.8 V vs.SCE).Background currents in the absence of catalyst were negligible.Using the electrocatalytic approach, 2-propanol and ethanol were oxidized to acetone and acetate, respectively, and acetaldehyde was oxidized to acetate.Toluene was oxidized to benzoate anion, p-xylene to terephtalate dianion, and p-phtalate anion to terephtalate quantitatively, in all three cases without the appearance of intermediates.Ethylene is unreactive, but cyclohexene was oxidized first to 2-cyclohexen-1-one and than to p-benzoquinone, which decomposes in solution.The (trpy)(bpy)Ru(OH2)²⁺ catalyst is greater than 75percent recoverable after 100 catalytic cycles.