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

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.