A Simple Synthetic Route to Obtain Pure Trans ‐Ruthenium(II) Complexes for Dye‐Sensitized Solar Cell Applications

We report a facile synthetic route to obtain functionalized quaterpyridine ligand and its trans ‐dithiocyanato ruthenium complex, based on a microwave‐assisted procedure. The ruthenium complex has been purified using a silica chromatographic column by protecting carboxylic acid groups as iso ‐butyl ester, which are subsequently hydrolyzed. The highly pure complex exhibits panchromatic response throughout the visible region. DFT/time‐dependent DFT calculations have been performed on the ruthenium complex in solution and adsorbed onto TiO 2 to analyze relative electronic and optical properties. The ruthenium complex endowed with the functionalized quaterpyridine ligand was used as a sensitizer in dye‐sensitized solar cell yielding a short‐circuit photocurrent density of more than 19 mA cm −2 with a broad incident photon to current conversion efficiency spectra ranging from 400 to 900 nm, exceeding 80 % at 700 nm.