Patent ID: 8610111

Claim:
A compound of formula (I) wherein: each M is the same or different and independently Fe, Co, Ru, or Os; each R 1 is the same or different and independently H, aryl, alkyl, aralkyl, R 5 -alkyl, R 5 -aryl, or R 5 -aralkyl; each R 2 is the same or different and independently aryl, alkyl, or heteroaryl; each R 3 is the same or different and independently H, aryl, alkyl, I, SR 6 , or P(R 6 ) 2 ; each R 4 is the same or different and independently H, aryl, alkyl, I, SR 6 , or P(R 6 ) 2 ; R 5 ═I, Br, OH, SH, CN, COOR 7 , CHO, SCN, N 3 , C 2 -C 4 alkenyl, C 2 -C 4 alkynyl, or phenylvinyl; R 6 =phenyl, or cyclohexyl; R 7 =methyl, ethyl, or benzyl; or enantiomers, diastereoisomers and salts thereof.