Patent ID: 7812251

Claim:
A photosensitizing transition metal complex having the general formula (Ia): MLY 1 (Ia) in which M is a transition metal selected from Ru(II), Os(II), Fe(II), Re(I) and Tc(I); L is a polypyridine ligand having the general formula (II): wherein at least one of A 1 , A 2 and A 3 is an anchoring group selected from —COOH, —COON(C 4 H 9 ) 4 , —PO(OH) 2 , —PO(OR 1 ) 2 (where R 1 is an alkyl group having 1 to 30 carbon atoms), —CO(NHOH), and when there is the remaining A 1 , A 2 and A 3 being not said anchoring group, it may be a hydrogen atom, an alkyl group having 1 to 50 carbon atoms, an alkylamide group having 2 to 50 carbon atoms or an aralkyl group having 7 to 50 carbon atoms, and Y 1 is a group selected from the formulae (IIIa) to (IIId): where R 3 is an alkyl group having 1 to 50 carbon atoms, an alkoxyalkyl group having 2 to 30 carbon atoms, an aminoalkyl group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkylamide group having 2 to 30 carbon atoms, a cyano group or a hydrogen atom.