This invention relates to a transition metal catalyst compound represented by the formula: LMX.sub.2 or (LMX.sub.2).sub.2 wherein each M is independently a Group 7 to 11 metal, preferably a Group 7, 8, 9, or 10 metal; each L is, independently, a tridentate or tetradentate neutrally charged ligand that is bonded to M by three or four nitrogen atoms, (where at least one of the nitrogen atoms is a central nitrogen atom and at least two of the nitrogen atoms are terminal nitrogen atoms), and at least two terminal nitrogen atoms are substituted with one C.sub.3 C.sub.50 hydrocarbyl and one hydrogen atom or two hydrocarbyls wherein at least one hydrocarbyl is a C.sub.3 C.sub.50 hydrocarbyl, and the central nitrogen atom is bonded to three different carbon atoms or two different carbon atoms and one hydrogen atom; X is independently a monoanionic ligand, or two X may join together to form a bidentate dianionic ligand.