A allyl-substituted salicylaldimine proligand (Scheme 1, Compound 5) was prepared by a condensation reaction, which reacted with trans-[NiCl(Ph)(PPh3)(2)] to give a binuclear neutral nickel (II) complex [((4-Allyl-2,6-iPr(2)C(6)H(2)) NCH)C6H3ONi(PPh3)Ph](2) (Scheme 1, Complex 6). The structure of the complex was characterized by H-1 NMR, C-13 NMR and elemental analysis. This novel complex bearing allyl groups can be used as a self-immobilizing catalyst for the polymerization of ethylene and does not need a cocatalyst for their catalytic performance. The self-immobilizing catalytic systems not only possess high activity (up to 5.23 x 10(5) g of PE/(mol of Ni h)) but also can produce high-molecular-weight polyethylenes (Mw = (0.42-0.71) x 10(6)) with relatively broad molecular weight distributions (MWD = 2.83-3.11). According to the C-13 NMR analyses, the resultant polyethylenes contain a few branched chains mainly consisting of methyl branches. (C) 2013 Elsevier B.V. All rights reserved.