Synthesis,Characterization,and Sensitizing Properties of Heteroleptic Ru~(II)Complexes Based on 2,6-Bis(1-pyrazolyl)pyridine and 2,2'-Bipyridine-4,4'-dicarboxylic Acid Ligands

摘要

Starting from the Ru(bpp)Cl3 precursor(1),a family of novel heteroleptic Ru~(II)complexes of the general formulae[Ru-(bpp)(dcbpyH)(X)][X=Cl~-(2a),NCS~-(3)]and Na[Ru(bpp)-(dcbpy)(CN)](4)with the ligands 2,6-bis(1-pyrazolyl)pyr-idine(bpp)and 2,2'-bipyridine-4,4'-dicarboxylic acid(dcbpyH2)has been synthesized,spectroscopically characterized,and attached to nanocrystalline TiO2 electrodes to be tested as solar cell sensitizers.Addition of HCl to(2a)led to the corresponding cationic derivative[Ru(bpp)(dcbpyH2)-C1]C1(2b).All complexes were characterized by FT-IR,FT-Raman,UV/Vis,1H NMR spectroscopy,elemental analysis,and mass spectrometry.Complex 4 and the previously reported[Ru(bdmpp)(dcbpyH2)Cl](PF6)(5)[bdmpp is 2,6-bis(3,5-dimethyl-1-pyrazolyl)pyridine]were characterized by single-crystal X-ray diffraction.The photo-electochemical properties of the dyes 2-4 were investigated and the efficiency of the corresponding dye-sensitized solar cells was compared to the sensitizing performance of the cis-[Ru(dcbpyH)2(NCS)2](NBu4)2(N719)dye.