Three five-coordinate transition metal complexes [2, 6-(PhNCMe) 2C5H3NMCl2· CH3CN](M= Zn, Cd, Hg)(named M1) have been assembled onto a nanocrystalline TiO2 film to prepare transition metal complex/N719 co-sensitized photoelectrodes for dye-sensitized solar cell applications. The metal center is chelated in a tridentate manner by the ligand and further coordinated by two chlorine atoms, resulting in distorted trigonal bipyramidal ...