Binuclear neutral nickel complexes bearing bis(bidentate) salicylaldiminato ligands: Synthesis, structure and ethylene polymerization behavior

Reaction of sodium salts of the bridging [O,N,N,O]-type bisalylaldimine ligands [O,N,N,O = [3-phenyl-2-OH-(CHdouble bond; length as m-dashN)]2-L (L = CH2CH2CH2 3a, 1,4-C6H4 3b)] with trans-bis(triphenylphosphane)phenylnickel (II) chloride result in neutral bis(bidentate) binuclear nickel (II) complexes 4a and 4b. The structure of 4b has been confirmed by X-ray crystallography. 4a shows moderate activity for polymerization of ethylene in the presence of methylaluminoxane (MAO). Catalytic activities, molecular weights and molecular weight distribution of polyethylene have been investigated under the various reaction conditions.