Linear polyethylene (PE) is, by nature, hydrophobic and strategies to modify this property include introduction of functional groups along the PE backbone through post-polymerization modification such as surface treatments, oxidation, "click" reactions, and C-H activation. Alternatively, copolymerization of ethylene with functional vinyl monomers can result in desired changes in the degree of hydrophobicity but often at the expense of the desired semi-crystalline properties of linear PE. Herein, the authors describe the synthesis of a dibenzobarrelene (DBB)-bridged, α-diimine Ni" catalyst (rac-3) which exhibits exceptional behavior for the polymerization of ethylene-affording high molecular weight with narrow dispersities and degrees of branching much lower compared to PE made by related ct-diimine nickel catalysts. The catalyst (rac-3) was synthesized by condensation of dione 1 with two equivalents of rac-4-methyl-2-(l-(2,4,6-trimethylphenyl) ethyl)aniline (rac-2, Scheme 1) followed by metalation with (dimethoxyethane)NiBr2.
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