| abstract |
The invention provides novel ligands for transition metal complexes which exhibit high coordination power with respect to metals by being free of substituents at the positions ortho to phosphorus or arsenic and which have electron-withdrawing power comparable to the highest level known in conventional ligands. A ligand of the invention includes a compound represented by General Formula (1): R 1 R 2 R 3 A or General Formula (2): R 1 R 2 A-Y-AR 3 R 4 and having a total of 15 to 110 carbon atoms. In the formulae, A is phosphorus or arsenic; R 1 , R 2 , R 3 and R 4 are each independently a substituted pyridyl group having optionally different electron-withdrawing groups bonded to the positions meta to the atom A as well as hydrogen atoms bonded to the positions ortho to the atom A; and Y is a divalent group derived from a C 2-20 , optionally substituted and optionally heteroatom-containing, aliphatic, alicyclic or aromatic compound or from ferrocene. |