Mono and bimetallic nickel bromide complexes bearing azolate-imine ligands: Synthesis, structural characterization and ethylene polymerization studies
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Date
2009
Journal Title
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Volume Title
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ELSEVIER SCIENCE SA
Abstract
The synthesis of N-(1-(3,5-dimethylpyrazol-1-yl)ethylidene)-2,6-diisopropylaniline (1) and N-(1-(indazol-2-yl)ethylidene)-2,6-diisopropylaniline (2) allowed access to new transition metal complexes. When reacted with dibromo(2,2'-dimethoxyethylether) nickel(II) the complexes [NiBr2{N-(1-(3,5-dimethylpyrazol-1-yl) ethylidene)-2,6-diisopropylaniline}] (3) and [Ni2Br2(mu-Br)2{N-(1-(indazol-1-yl)ethylidene)-2,6-diisopropylaniline} 2] (4) are yielded, respectively. The addition of MAO generates catalytically active species for the homopolymerization of ethylene. The polymer products were low molecular weight (3-6 K) and a monomodal molecular weight distribution, consistent with the presence of a single active site. In addition, the catalyst was found to efficiently oligomerize higher olefins to high molecular weights with narrow PDIs. (C) 2009 Elsevier B.V. All rights reserved.
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Keywords
Nickel, Azolate-imine ligands, Ethylene polymerization, Branching PE, Late transition metal catalysts, OLEFIN POLYMERIZATION, ALPHA-OLEFINS, LIVING POLYMERIZATION, TITANIUM COMPLEXES, REMOTE ACTIVATION, CATALYSTS, OLIGOMERIZATION, COPOLYMERS, TRIS(PENTAFLUOROPHENYL)BORANE, POLYETHYLENES