The electronic structure of the cis-bis(4,4'-dicarboxy-2,2'-bipyridine)-bis(isothiocyanato)ruthenium(II) complex and its ligand 2,2'-bipyridyl-4,4'-dicarboxylic acid studied with electron spectroscopy

The electronic structure of cis-bis(4,4'-dicarboxy-2,2'-bipyridine)bis(isothiocyanato)ruthenium(II) and of its ligand 2,2'-bipyridine-4,4'-dicarboxylic acid was studied with electron spectroscopy. Valence level spectra were studied with respect to photoelectron angular distributions and photon energy dependence. The exptl. information coupled with semi-empirical INDO/S calcns. provides a mapping of the orbital parentage of the dye complex and its ligands. The energy levels of the dye complex in the context of a sensitized semiconductor (nanostructured TiO2) surface are related to the bands of the semiconductor.