Molecular Modelling of Ionic Liquid Ligands based Zirconium Complexes for Ethylene Copolymerization with Octene-1

Abstract

This paper presents the results of obtaining new easily preparing zirconium-containing complex catalytic systems for ethylene copolymerization and their theoretical studies. The synthesized arylimine metal complexes with “grafted” ionic-liquid ligands have been tested in the liquid-phase copolymerization process of ethylene in the aromatic solvents medium. It has been shown that the prepared catalytic systems can be used together with ionic liquids such as [bmim]BF4 and [bmim] HSO4. Using of organoaluminum compounds such as methylaluminiumoxane and (C2H5)2AlCl, these catalytic systems provide the formation of mixtures of the linear PE with high density, different thermodynamic characteristics, molecular mass distribution and crystallinity. It was found that these catalytic systems allow to control the structure and composition of the products obtained. It is known that in organometallic catalysis, ligands within a metal complexes play an important role in the formation of catalytic active centers. The nature of the catalytic centers also has a great influence on preparation of (co)polymers with various structures. Therefore, the choice of ligands is a very important factor for obtaining products with desired properties. The structural parameters of the synthesized catalytic systems were investigated using HyperChem software (version 8, Hypercube Inc.). Activation energy, dipole moment, bond angle, the bond length, the HOMO and LUMO orbitals have been calculated.