Effect of steric hindrance on photoinduced electron transfer of self-assembled monolayers of three isomeric Ru(II)-bipyridine complexes on ITO electrode

Abstract

Three kinds of self-assembled monolayers (SAMs) of isomeric Ru(II)-bipyridine complexes: cis-di(thiocyanato)-bis(2,2′-bipyridyl-3,3′-dicarboxylate) ruthenium (dye A), cis-di(thiocyanato)-bis(2,2′-bipyridyl-4,4′- dicarboxylate) ruthenium (dye B) and cis-di(thiocyanato)-bis(2,2′-bipyridyl-5,5′- dicarboxylate) ruthenium (dye C), were fabricated on hydrophilic transparent indium tin oxide (ITO) electrode. The UV-visible spectra, contact angle, XPS and cyclic voltammetry of these SAMs were measured. The photoinduced electron transfer properties were determined both in propylenecarbonate (PC) electrolyte and KCl electrolyte. A possible mechanism of electron transfer of these systems was proposed.