Abstract

Nickel complexes prepared using a 4-(2,6-diisopropylphenylimino)-3,3-dimethylpentan-2-one ligand framework are shown. The potassium salt of the ligand is obtained by deprotonation with KH in diethyl ether. Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olate can then be reacted with Ni(PMe3)2(?1-CH2Ph)Cl to yield 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-?1O](?1-CH2Ph)(PMe3)2Ni (1). The potassium salt of the ligand can also be reacted with Ni(PMe3)(?3-CH2Ph)Cl to yield bis(4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-?2N,O](?1-CH2Ph)2Ni2 (2) or 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-?2N,O](?1-CH2Ph)(PMe3)Ni (3), depending on the reaction conditions. The addition of five equivalents of B(C6F5)3 to 1, 2, or 3 yields catalytically active species for the homopolymerization of ethylene. The polymer products are described by a single molecular weight distribution, consistent with the presence of a single active site. © 2008 Elsevier B.V. All rights reserved.