A series of 2-(1-(2,4-dibenzhydrylnaphthylimino) ethyl)6-(1-(arylimino) ethyl) pyridyliron(II) complexes (Fe1-Fe5) was synthesized and characterized. The molecular structure of the representative Fe2 was determined by single-crystal X-ray diffraction, revealing a distorted pseudo-square-pyramidal geometry around the iron center. On activation with eithermethyl aluminoxane (MAO) or modified methylaluminoxane (MMAO), all these iron complex precatalysts performed with high activities (up to 1.58 x 10(7) g (PE) mol(-1) (Fe) h(-1)) toward ethylene polymerization, producing highly linear polyethylenes with highmolecular weight and bimodal distribution, which was in accordance with high temperature C-13 NMR, high T-m values (T-m similar to 130 degrees C) and the GPC curves of the obtained polyethylenes. Meanwhile, DFT calculation results also showed the good correlation between net charges on iron and experimental activities. Compared with previous bis(imino) pyridyliron analogues, the current iron complexes containing the benzhydrylnaphthyl groups exhibited relatively higher activities and better thermalstability at elevated temperatures, especially at 80 degrees C as the industrial operating temperature, and still showed high activities toward ethylene polymerization up to 8.57 x 10(6) g (PE) mol(-1) (Fe) h(-1) in the presence of co-catalyst MMAO. In addition, these iron complex precatalysts all exhibited long lifetimes. (C) 2017 Wiley Periodicals, Inc.