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.