Synthesis and photophysical properties of new ruthenium(II) charge-transfer sensitizers containing a 4,7-bis(E-carboxyvinyl)-1,10-phenanthroline ligand

A series of ruthenium(II) complexes containing carboxyvinyl-conjugated phenanthroline and another auxiliary ligand have been designed, synthesized, and characterized. Starting from [RuCl2(p-cymene)](2), two types of Ru(II) complexes, [Ru(dcvphen)(4,7-R-2-phenanthroline)(NCS)(2)] and [Ru(dcvphen)(4,4'-R-2-bipyridine)(NCS)(2)] (dcvphen = 4,7-bis(E-carboxyvinyl)-1,10-phenanthroline, R = -CH = CHCOOH, -COOH, H), were synthesized by a one-pot reaction in DMF. Final products were obtained as a tetrabutylammonium salt form of Ru(II) complexes with reasonable yields. UV-Vis absorption studies on the newly synthesized Ru(II) complexes were carried out. Furthermore, it was shown that a dye-sensitized solar cell fabricated with representative [Ru(dcvphen)(2)(NCS)(2)][TBA](2) complex dye exhibited a reasonable power conversion efficiency of 1.0 %.