Preparation and study of ruthenium(II) 2,2′:6′,2″-terpyridine complexes linked by an O–CH2 spacer to thiophene moieties

Two ligands whose general formula is R-terpy with terpy = 2,2′:6′,2″-terpyridine bearing at the 4′-position a substituent R = 2-thenyloxy and 3-thenyloxy were synthesised. The electronic spectra and the electrochemical behaviour of the corresponding Ru(II) complexes were investigated. The donor effect of the grafted groups as the non-conjugation between the Π* ligand orbitals of the terpyridine and the thienyl groups induce an increase of the energy level of the LUMO.