A transition metal ligand complex has the following formula: ##STR00001## wherein R.sub.1 and R.sub.2 (each occurrence) independently represent an aryl, alkyl, or cycloalkyl group having up to 20 carbon atoms; R.sub.3 and R.sub.4 (each occurrence) independently represent an aryl, alkyl, or cycloalkyl group having up to 20 carbon atoms; R.sub.5 represents an aryl, alkyl, or cycloalkyl group having up to 20 carbon atoms, provided that R.sub.4 and R.sub.5 may be joined to form a cyclic structure; R.sub.6 represents an alkyl or aryl group having up to 20 carbon atoms; and Mt represents a transition metal selected from Group 7, 8, 9, 10, 11, or 12 of the Periodic Table of the Elements.