Patent ID: 7759490

Claim:
A compound of structure III: wherein: A is Os or Ru; L stands for a neutral donor ligand other than CO; L can occupy either cis or trans orientation; X 1 , X 2 and X 3 are independently C or N; when X 2 is N, R 1 is omitted; when X 3 is N, R 2 is omitted; R 1 is H, C1-C8 alkyl, C1-C8 substituted phenyl or C1-C4 perfluoroalkyl; R 2 is H, F and/or a cyano substituent; X 4 of the hexagonal fragment is either C or N; X 4 may be located at any position of the hexagonal ring other than at the already present N position or the C-atom connecting the hexagonal ring to the pentagonal ring when X 4 is N and R 3 and R 4 are not linked to X4; and R 3 is H, or C1-C3 alkyl; R 4 is H, or C1-C3 alkyl, or; R 3 and R 4 together form the additional conjugated unit with structure