[Ru(bpy)2(bdppz)][tosyl] Photochemistry in Nafion Polymer Films

Abstract

We report the synthesis of [Ru(bpy)2(bdppz)][tosyl] (bpy=2,2?-bipyridine; bdppz=benzo[i]dipyrido[3,2-a:2?,3?-c]phenazine; tosyl=tosylate) for its use in photoelectrochemical experiments. [Ru(bpy)2(bdppz)][tosyl] readily incorporates into nafion polymer films cast onto carbon electrodes, and undergoes a bdppz-based reduction at -350mV. Excitation of [Ru(bpy)2(bdppz)][tosyl] at 480nm within the film results in reductive photocurrents at 0V. This process becomes catalytic in the presence of an irreversible oxidative quencher [Co(en)2Cl2] (Co=cobalt(III); en=ethylene diamene). The excited state of [Ru(bpy)2(bdppz)][tosyl] is oxidatively quenched by this [Co(en)2Cl2]. Then it is reduced by the electrode, regenerating back to its original state: Ru(II).