2-(Benzimidazol-2-yl)-1,10-phenanthrolyl metal (Fe and Co) complexes and their catalytic behaviors toward ethylene oligomerization

The N∧N∧N-tridentate metal complexes, LMCl2 (M = Fe or Co; L represents a ligand of 2-(benzimidazol-2-yl)-1,10-phenanthrolines), were synthesized and fully characterized with spectroscopic and elemental analysis. The single-crystal X-ray crystallographic analyses revealed complex 1a with a distorted octahedron geometry due to incorporating one methanol molecule, and complexes 5a and 9b with a distorted trigonal-bipyramidal geometry. Upon activation with modified methylaluminoxane (MMAO), these complexes showed good to high catalytic activities toward ethylene oligomerization. The detailed investigations were carried out to disclose the influences of various reaction conditions and nature of ligands on their performing activities of metal complexes.