Patent ID: 7560554

Claim:
A compound represented by formulae (I) or (II): wherein M is Rh or Ir; Y is the same or different and is O, S, or Se; R is the same or different on each occurrence and is H, F, Cl, Br, NO 2 , CN, or a straight-chain or branched or cyclic alkyl or alkoxy group having 1 to 20 carbon atoms, wherein one or more non-adjacent CH 2 groups is optionally replaced by —O—, —S—, —NR 1 — or —CONR 2 — and wherein one or more H atoms is optionally replaced by F, or an aryl or heteroaryl group having 4 to 14 carbon atoms which are optionally substituted by one or more non-aromatic radicals R; R 1 and R 2 are each the same or different and are 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.