2,6-Dibenzhydryl-N-(2-phenyliminoacenaphthylenylidene)-4-chloro-aniline nickel dihalides: Synthesis, characterization and ethylene polymerization for polyethylenes with high molecular weights

A series of 2,6-dibenzhydryl-N-(2-phenyliminoacenaphthylenylidene)-4-chloroanilines (L1–L5) and their nickel halide complexes LNiX2 (X = Br, C1–C5; X = Cl, C6–C10) were synthesized. All organic compounds were characterized by FT-IR and NMR spectroscopy and elemental analysis. The nickel complexes were characterized by FT-IR spectroscopy, elemental analysis and their structures were determined by single-crystal X-ray diffraction. Upon activation with MAO, all of these nickel complexes showed high activities (up to 107 g of PE (mol of Ni)−1 h−1) for ethylene polymerization. The resulting polyethylenes possess high molecular weights (Mw up to 106 g mol−1) and feature high degrees of branching. The MM-QEq method was employed to assess the ligandsʹ effects on catalytic activities. The results show that higher net charges on the nickel core correlate directly with higher measured activities.