A new series of promising synthetically facile cycloruthenated thiophene-based sensitizers have been developed and fully characterized by UV–vis spectroscopy, NMR and cyclic voltammetric studies. The synthesized dyes have broad MLCT bands spanning the visible spectrum, with high extinction coefficients. The energies of the molecular orbitals for the isolated molecules of the complexes and densities of occupied states were determined. The cycloruthenated compounds contains ortho-metallated thiophene moiety substituted by N-(methyliden)aniline or pyridine-2-yl at the ortho-position. Having 4,4’-dicarboxy-2,2’-bipyridine as the linker and auxiliary ligands and anchored to nanocrystalline TiO2 films, they achieve efficient sensitization in the visible range and display an overall conversion efficiency of 5.3% under standard AM 1.5 sunlight.