Ethylene polymerization catalyzed by metallocene/methylaluminoxane systems: quantum-mechanical study on the role of olefin separated ion pairs (OSIP) in the polymerization mechanism
✍ Scribed by Roberto Fusco; Luca Longo; Antonio Proto; Francesco Masi; Fabio Garbassi
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 480 KB
- Volume
- 19
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
DFT (density-functional theory) calculations were performed to investigate the thermodynamics of formation of Olefin Separated Ion Pairs (OSIP) Cp2MtCH~/C2H4/Cl2AI[O(A1Me3)AlHMe]; (Cp = q5-C5H5, Mt = Ti, Zr, Me = CH3) from ethylene and Cp2MtMe * C12AI[O(AlMe3)A1HMe]2, a model of adduct produced by metallocene/methylaluminoxane (MAO) systems for olefin polymerization. The results account for the high cocatalytic activity of MA0 and show that titanium complexes are potentially more active than zirconium homologues, as confirmed by low temperature polymerization tests.