A series of 2,6-dibenzhydryl-N-(2-phenyliminoacenaphthylenylidene)-4- chloroanilines (L1-L5) and their nickel halide complexes LNiX (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 10 7 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 ligands' effects on catalytic activities. The results show that higher net charges on the nickel core correlate directly with higher measured activities.