New bi-nuclear and multi-nuclear α-diimine/nickel catalysts for ethylene polymerization

Bi-nickel-centre catalysts and multi-nickel-centre catalysts were prepared by Schiff-base condensation of 2,3-butanedione with 2,6-diisopropylaniline and/or substituted bis-aniline, which demonstrated efficient catalytic activity for ethylene polymerisation under the activation of methyl aluminoxane (MAO).