A high molar extinction coefficient Ru(II) complex functionalized with cis -dithiocyanato-bis-(9-anthracenyl-10-(2-methyl-2-butenoic acid)-1,10- phenanthroline): Potential sensitizer for stable dye-sensitized solar cells

New heteroleptic ruthenium(ii) complex was formulated as [ru(l 1)2(ncs)2],where l1 = 9-anthracenyl-10-(2-methyl-2-butenoic acid)-1,10-phenanthroline was synthesized and its photophysical properties were studied and compared to previously reported analogue complex containing no anthracene moiety [ru(l 2)2(ncs)2],l2 = (2-methyl-2-butenoic acid)-1,10-phenanthroline. the two complexes though exhibit very strong molar extinction coefficient values; however,[ru(l 1)2(ncs)2] shows better characteristic broad and intense metal-to-ligand charge transfer (mlct) absorption band and higher molar absorptivity coefficient at ( m a x = 522 nm,ε = 6.60 × 10 4 m-1 cm-1) than that of [ru(l2) 2(ncs)2] complex,( m a x = 446 nm,ε = 4.82 × 10 4 m-1 cm-1). at room temperature,long wavelength emissions with strong intensity ratio centered at 660 nm were recorded for [ru(l1)2(ncs)2] complex with a bathochromic shift ( e m = 700 nm) for [ru(l2)2(ncs)2] complex. it was shown that the luminescence wavelength characteristic of the complexes may be a function relating to the increasing length of π-conjugation and/or molecular weight. a preliminary cyclic voltammetry of [ru(l1)2(ncs)2] complex also exhibits good electroredox activity with oxidation potential of about 1.04 v,significantly better than other ru(ii) polypyridine complexes containing bidentate ligands. © 2014 adewale o. adeloye and peter a. ajibade.