. . . "Compounds represented by the following general formula, disclosed in JP-A-10-088121 wherein Q9 and Q10 are independently a ligand represented by the following formula (I); and L6 is a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, ???OR47 wherein" .