A novel ruthenium sensitizer with -OMe substituted phenyl-terpyridine ligand for dye sensitized solar cells

A new ruthenium photosensitizer [Ru(triOMePhtpy)(bpydra)(NCS)]PF6 (1) (triOMePhtpy = 4'-(3,4,5-triOMe)Phenyl-2,2':6',2"-terpyridine; bpydca = 4,4'-dicarboxy-2,2'-bipyridine) has been synthesized and characterized by IR, UV-Vis, NMR and Mass spectroscopy. The molecule shows a moderately intense MLCT band at 511 nm. Along with the intraligand transitions in the UV region, the molecule shows several high energy MLCT bands which has been nicely manifested by the TDDFT calculation. DFT optimized structure shows a distorted octahedral geometry around central ruthenium atom, where the phenyl ring attached to the 4' position of terpyridine moiety makes a torsion angle of 34.09 degrees with the central pyridine ring. pK(a) of the -COOH functionalities was determined spectrophotometrically by monitoring the variation of MLCT band position with pH and found to be similar to 3.98. Photovoltaic measurements of the present dye in a typical DSSC configuration was found to exhibit Jsc = 5.10 mA cm(-2), FF = 66.02%, Voc = 0.68 V and eta = 4.62% at an optimized intensity of 50 mW cm(-2). (c) 2016 Published by Elsevier Ltd.