Novel, Highly Active Binuclear 2,5-Disubstituted Amino-p-benzoquinone−Nickel(II) Ethylene Polymerization Catalysts†

Reaction of salts of the 2,5-disubstituted amino-p-benzoquinone bridging ligand (1a−e) with trans-bis(triphenylphosphane)phenylnickel(II) chloride results in the binuclear complexes 2a−e, which show high activities for ethylene polymerization without any cocatalysts. High-molecular-weight, moderately branched polyethylene of broad molecular-weight distribution was obtained.