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DFT modeling of the post-titanocene catalytic system LTiCl2-Bu2Mg-Et2AlCl for alkene polymerization: The role of alkyl bridge Mg-C-Ti and β-agostic C-H-Ti bonds in the formation of active centersстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 13 февраля 2017 г.
- Автор: Ustynyuk Leila Y.
- Журнал: Journal of Molecular Catalysis A: Chemical
- Том: 426
- Год издания: 2017
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 600
- Последняя страница: 609
- DOI: 10.1016/j.molcata.2016.09.027
- Аннотация: DFT modeling of the active centers formation in the catalytic system LTiCl2-Bu2Mg-Et2AlCl for alkene polymerization, where L is a bidentate ligand of saligenin type, suggests the three-step mechanism of this process. This mechanism includes the addition of the most probable alkylating agent, RMg(μ-Cl)2AlR2 or RMg(μ-Cl)2MgR (R = alkyl), to LTiCl2 with the formation of the trinuclear heterocomplex with the alkyl bridge bond Mg C Ti, followed by its two-step isomerization into the active center via the β-agostic intermediate. The free energy changes at the stages of the addition and isomerization are negative; the maximal energy barrier on the reaction pathway is small. In the Mg-free system LTiCl2-AlR3, the isomerization proceeds through the single energy barrier with a significantly higher amplitude. This could be the reason for a relatively high activity of the Mg-containing system and inactivity of the Mg-free system.
- Добавил в систему: Устынюк Лейла Юрьевна