The influence of the ligand structure on the properties of (α-diimine)nickel catalysts in the polymerization and oligomerization of ethylene

Abstract

(α-Diimine)nickel(II) dihalide complexes are suitable catalyst precursors for the polymerization and oligomerization of olefins after activation with methylaluminoxane (MAO). The catalytic properties of these complexes and the character of the obtained polymers depend on the ligand structure of the used catalysts. Substituents on the arene moiety and/or the backbone of the ligand influence the active site of the catalyst during the polymerization reaction. Therefore, polymerization products of low molecular weights (oligomers) to high molecular weights (polymers) can be obtained. Activities, molecular weights of the products and the formation of various isomers of the obtained oligomers show clear dependencies on the molecular structure of the catalyst precursors.