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

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.