Synthesis and ethylene polymerization of 8-(fluorenylarylimino)-5,6,7-trihydroquinolylnickel chlorides: Tailoring polyethylenes by adjusting fluorenyl position and adduct Et2Zn

A series of 8-(arylimino)-5,6,7-trihydroquinolines ligand pendant fluorenyl group at N-aryl ring, and their nickel complexes (Ni1-Ni5) have been prepared and characterized. Once activated with Et2AlCl, the complexes Ni1, Ni2, and Ni3 bearing ligands from para-fluorenylaniline produced unimodal polyethylenes; on the contrary complexes Ni4 and Ni5 gave bimodal polyethylenes due to steric influence of ligands from ortho-fluorenyl anilines. With a increment of Et2Zn/Ni4 ratio from 0 to 400, the distinct bimodel polyethylenes were obtained with molecular weights shifted from 14.3 to 57.6 kgmol(-1); apart shiftment to higher molecular weights, the portion of low molecular weight decreased along with higher portion of high molecular weight. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1910-1919