Ethylene polymerization catalyzed by metallocene/methylaluminoxane systems: quantum‐mechanical study on the role of olefin separated ion pairs (OSIP) in the polymerization mechanism

摘要: DFT (density-functional theory) calculations were performed to investigate the thermodynamics of formation Olefin Separated Ion Pairs (OSIP) Cp2MtCH3+/C2H4/Cl2Al[O(AlMe3)AlHMe] (Cp = η5-C5H5, Mt Ti, Zr, Me CH3) from ethylene and Cp2MtMe · Cl2Al[O(AlMe3)AlHMe]2, a model adduct produced by metallocence/methylaluminoxane (MAO) systems for olefin polymerization. The results account high cocatalytic activity MAO show that titanium complexes are potentially more active than zirconium homologues, as confirmed low temperature polymerization tests.