Electrocatalysis in photochemically activated electropolymerized thin films

In reductively electropolymerized thin films of poly-cis-[Ru(vbpy)(2)(py)(2 )](PF6)(2) ("vbpy" is 4-methyl-4'-vinyl-2,2'-bipyridine and "py" is pyridin e), on glassy carbon electrodes, photochemical ligand loss with aqueous HCl O4 in the external solution occurs to give poly-cis-[Ru(vbpy)(2)(OH2)(2)](C lO4)(2), but the efficiency of ligand loss is greatly decreased compared to the efficiency in solution. In cyclic voltammograms of films containing th e aqua complex, there is evidence for both Ru-III/II and higher oxidation s tate Ru-IV/III, Ru-V/IV, and Ru-VI/V couples. The redox chemistry of the re sulting films is dictated by the film structure and can be controlled by va rying the electropolymerization conditions and external solution compositio n. The oxidation of alcohols by these higher oxidation state couples has be en investigated electrochemically.