The synthesis, photophysical properties and water oxidation studies of a series of novel photosensitizer–catalyst assemblies.

A novel series of bridging ligands and their Ru II photosensitizer–catalyst dyads have been prepared and characterized by NMR and electronic absorption spectroscopy as well as cyclic voltammetry. The presence of asymmetry in the ligands facilitated selective metal coordination, which greatly enhanced the ease of the preparation of the dyads. The photophysical properties of the photosensitizers and the photosensitizer–catalyst dyads were also studied. All the photosensitizers were found to be strong emitters while the extremely weak emission of the dyads suggested quenching by either energy or electron transfer. The water oxidation activities of the dyads have been evaluated under both light and Ce IV activated conditions. The dyads were found to be active under Ce IV activated conditions. Electrochemical studies also suggest that these systems may be used as electrocatalysts for photoelectrochemical water oxidation. [ABSTRACT FROM AUTHOR]