Patent ID: 7125998

Claim:
A compound of the formula (I) or (II) wherein M is Rh or lr, X is the same or different and is F, Cl, Br or I, Y is the same or different and is 0, S or Se, R is the same or different at each occurrence and is H, F, Cl, Br, NO 2 , CN, a straight-chain or branched or cyclic alkyl or alkoxy group which has from 1 to 20 carbon atoms and in which one or more nonadjacent CH 2 groups is optionally replaced by —O—, —S—, —NR 1 — or —CONR 2 — and in which one or more hydrogen atoms in said alkoxy group is optionally replaced by F, or an aryl or heteroaryl group having from 4 to 14 carbon atoms which is optionally substituted by one or more nonaromatic R radicals; and a plurality of R substituents, either on the same ring or on the two different rings together in the same ligand in turn optionally encompasses a further monocyclic carbon ring system; R 1 and R 2 are the same or different and are each H or an aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms, a is the same or different and is 0, 1, 2, 3 or 4, b is the same or different and is 0, 1, 2 or 3, and n is 1, 2 or 3.