Enhancing α-Diimine Catalysts for High-Temperature Ethylene Polymerization

Abstract

Sterically demanding 2,6-bis(diphenylmethyl)-4-methylaniline was condensed onto acenaphthenequinone via an aminoalane intermediate and metalated using nickel(II) dibromide dimethoxyethane adduct to yield bis[(2,6-dibenzhydryl-4-methylimino) acenaphthene]dibromo nickel(II). This α-diimine precatalyst was examined for high-temperature ethylene polymerization and proved to be thermally robust at temperatures as high as 90 °C, demonstrating enhanced activity as compared with related catalysts. Furthermore, the resultant polymers displayed increased melting transitions as compared with those produced using catalysts with identical N-aryl moieties appended to nonacenaphthenequinone-derived ligand backbones.