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.

Graphical abstractNickel halide complexes of the type L2NiX2 bearing 2-benzimidazolyl-N->arylquinoline-8-carboxamide ligands exhibited good to high activities in ethylene oligomerization upon activation with Et2AlCl, and performed with good activities for the vinyl polymerization of norbornene in the presence of MAO.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Bis(tridentate ligated) nickel dihalides of the type L2NiX2. ► 2-Benzimidazolyl-N-aryylquinoline-8-carboxamide tridentate ligands. ► Distorted octahedral geometry around cationic nickel. ► Nickel pre-catalysts exhibited good activities in ethylene oligomerization. ► Nickel pre-catalysts for the vinyl polymerization of norbornene.