Synthesis and photoelectric studies of Ru(II) polypyridyl sensitizers

New cis-Ru(3,3'-dcbpy)(2)(NCS)(2) photosensitizer (where 3,3'-dcbpy is 3,3' -dicarboxy-2,2'-bipyridine) was synthesized using Ru(DMSO)(4)Cl-2 as a star ting material and characterized. Its photophysical and redox properties wer e compared with those of cis-Ru(4,4'-dcbpy)(2)(NCS)(2) and cis-Ru(5,5'-dcbp y)(2)(NCS)(2). The photoelectrochemical properties of the three dyes adsorb ed on the surface of the nanocrystalline TiO2 electrodes as well as on self -assembly monolayers (SAMs) were investigated. The photocurrents generated by sensitized TiO2 electrodes were much higher than those by SAMs. And cis- Ru(4,4'-dcbpy)(2) showed a most efficient photosensitizer in both systems. The mechanism is discussed in the paper. (C) 2000 Published by Elsevier Sci ence S.A. All rights reserved.