A zwitterionic nickel-olefin initiator for the preparation of high molecular weight polyethylene

Addition of 2 equiv. B(C6F5)3 to [3-(2,6-diisopropylphenylimino)-but-1-en-2-olato](η1-benzyl)(trimethylphosphine)nickel (1) results in the formation of 2-tris(pentafluorophenyl)borate-3-(2,6-diisopropylphenylimino)-but-1-ene(η3-benzyl)nickel (2), in which the borane coordinates to the oxygen of the ligand and forces binding of the olefin to nickel. Compound 2 can be used to initiate the homopolymerization of ethylene to obtain high molecular weight materials.