Three new three-dimensional geometry bulky a-diimine ligands (L) containing electron-donating and electron with drawing groups, 9,10-dihydro-9,10-ethanoanthracene-11,12-di(Ar)imine (Ar=p-PhCH3, L1; Ar=p-PhCl, L2; Ar= p-PhCF3, L3.), and their corresponding single Ni(II) catalysts, NiL2Br2 (Ni(L1) 2 Br-2, Ni(L2)(2)Br-2, and Ni(L3)(2)Br-2, were synthesized and the molecular structure were determined by X-ray crystallography. All NiL2Br2 catalysts were tested for norbornene polymerization and copolymerization of norbornene with 1-alkene after activation with B(C6F5)(3). The results that the polymerization catalytic activities for norbornene up to 10(5) g(polymer)/mol(Ni)-h even at 140 degrees C, shown that NiL2Br2 catalysts have high thermal stability. Meanwhile, catalysts with electron-withdrawing groups could achieve higher reactivity. The obtained poly(NB-co-1-alkene)s were confirmed to be vinyl-addition copolymers and noncrystalline. All copolymers exhibited high 1-alkenes insertion ratio, good thermal stability (T-d> 375 degrees C), high molecular weight (up to 10(5) g/mol), good solubility in common organic solvents and could be processed into films with good transparency in the visible region. (C) 2016 Wiley Periodicals, Inc.