Nickel halide complexes bearing 2-benzimidazolyl-N-arylquinoline-8-carboxamide derived ligands: Synthesis, characterization and catalytic behavior towards ethylene oligomerization and the vinyl polymerization of norbornene

Nickel halide complexes of the type L2NiX2 (Ni1–Ni6, X = Cl; Ni7–Ni12, X = Br) bearing 2-benzimidazolyl-N-arylquinoline-8-carboxamide derived ligands have been synthesized and characterized by IR spectroscopy and elemental analysis. The molecular structures of the representative nickel complexes Ni8 and Ni11 revealed a distorted octahedral geometry at the nickel center. Upon activation with Et2AlCl, all such nickel pre-catalysts exhibited high activities for ethylene oligomerization. Furthermore, in the presence of MAO, they were shown to perform with good activities for the vinyl polymerization of norbornene.