Electrochemical behavior of binuclear [Ru(L)(CO)2(CH3CN)]22+ complexes (L = 2,2′-bipyridine substituted by pyrrole groups). Their reductive and oxidative electropolymerization

The binuclear [Ru(bpy)(CO)2(CH3CN)]22+ (bpy = 2,2′-bipyridine) complex is an excellent precursor for the formation of redox polymeric Ru–Ru bonded films [Ru(bpy)(CO)2]n on electroactive surfaces by a two-electron reduction process. The resulting molecular cathodes are highly efficient electrocatalysts for the selective reduction of CO2 in pure aqueous media. In this paper, the simple in situ synthesis and the electrochemical behavior of a series of binuclear complexes [Ru(L)(CO)2(CH3CN)]22+ (L = bipyridyl ligands substituted by one or more pyrrole groups) are reported. In addition, to generating [Ru(L)(CO)2]n electropolymerization, anodic oxidation of the complexes allow the formation of functionalized polypyrrole films. The electrochemical properties of these films towards CO2 reduction have been also investigated.