Synthesis, characterisation and ethylene oligomerization behaviour of N-(2-substituted-5,6,7-trihydroquinolin-8-ylidene)arylaminonickel dichlorides

Abstract

A series of N-(2-substituted-5,6,7-trihydroquinolin-8-ylidene)-arylaminonickel(II) dichlorides were synthesized by the one-pot stoichiometric reaction of nickel dichloride, 2-chloro- or 2-phenyl-substituted 5,6,7-trihydroquinolin-8-one, and the corresponding anilines. All nickel complexes were characterized by elemental and spectroscopic analysis. The molecular structures of representative nickel complexes, determined by the single-crystal X-ray diffraction, indicate the different coordination numbers around nickel either four with more bulky ligands or five with less bulky ligands. All nickel complexes, activated with ethylaluminium sesquichloride (Et₃Al₂Cl₃), showed high activities (up to 9.5 × 10⁶ g mol⁻¹ h⁻¹) in ethylene oligomerization for dimer and trimers.