Patent ID: 7589215

Claim:
A ligand represented by formula (1) wherein R is selected from the group consisting of (C 1 -C 8 )-alkyl, HO—(C 1 -C 8 )-alkyl, (C 2 -C 8 )-alkoxyalkyl, (C 6 -C 18 )-aryl, (C 7 -C 19 )-aralkyl, (C 1 -C 8 )-alkyl-(C 6 -C 18 )-aryl, (C 3 -C 8 )-cycloalkyl, (C 1 -C 8 )-alkyl-(C 3 -C 8 )-cycloalkyl and (C 3 -C 8 )-cycloalkyl-(C 1 -C 8 )-alkyl, Q is selected from the group consisting of O and N—R′ and R′ is selected from the group consisting of H, (C 1 -C 8 )-alkyl, (C 6 -C 8 )-aryl and (C 1 -C 8 )-alkyl-(C 6 -C 18 )-aryl.