Formation and Nature of the Active Sites in Bis(imino)pyridine Iron-Based Polymerization Catalysts Научная публикация
| Журнал |
Organometallics
ISSN: 0276-7333 , E-ISSN: 1520-6041 |
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| Вых. Данные | Год: 2009, Том: 28, Номер: 11, Страницы: 3225-3232 Страниц : 8 DOI: 10.1021/om8010905 | ||
| Ключевые слова | Alumina Catalysi sCatalysts Chemical activation Electron resonance Electron spin resonance spectroscopy Ethylene Paramagnetic resonance Polymerization Polymers Pyridine Quantum theory Spin dynamics | ||
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| Организации |
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Информация о финансировании (1)
| 1 | Российский фонд фундаментальных исследований | 09-03-00485 |
Реферат:
The activation of 2,6-bis(2,6-diisopropylphenylimino)ethylpyridine iron-based catalysts of ethylene polymerization with methylalumoxane (MAO) and aluminum trialkyls has been studied in detail by 1H NMR and EPR spectroscopy. Neutral catalytically active species are formed in LiPrFeCl2/Al(Alk)3 systems. They are complexes [LiPr(−)Fe(+)(μ-Me)2AlMe2] (6) or [LiPr(−)Fe(+)(μ-iBu)(μ-X)Al(iBu)2] (7 or 8, X = iBu or Cl), depending on the activator used (either AlMe3 or Al(iBu)3). On the contrary, when “AlMe3-free” methylalumoxane (PMAO) is used as the activator, catalytically active ion pairs of the type [LFeII(μ-Me)2AlMe2]+[MeMAO]− (3) are formed. Intermediates 6 and 8 are relatively unstable and decay within minutes at room temperature, giving rise to an EPR-active iron species with a signal at g = 2.08, presumably of the type L′FeI−Alk (L′FeI(μ-Alk)2Al(Alk)2) in the low-spin state S = 1/2 (where L′ is a modified bis(imino)pyridine ligand). Polymer properties for the different catalyst/activator systems are presented.
Библиографическая ссылка:
Brylyakov K.P.
, Talzi E.P.
, Semikolenova N.V.
, Zakharov V.A.
Formation and Nature of the Active Sites in Bis(imino)pyridine Iron-Based Polymerization Catalysts
Organometallics. 2009. V.28. N11. P.3225-3232. DOI: 10.1021/om8010905 WOS Scopus РИНЦ CAPlusCA OpenAlex
Formation and Nature of the Active Sites in Bis(imino)pyridine Iron-Based Polymerization Catalysts
Organometallics. 2009. V.28. N11. P.3225-3232. DOI: 10.1021/om8010905 WOS Scopus РИНЦ CAPlusCA OpenAlex
Даты:
| Поступила в редакцию: | 16 нояб. 2008 г. |
| Опубликована online: | 1 мая 2009 г. |
| Опубликована в печати: | 8 июн. 2009 г. |
Идентификаторы БД:
| Web of science: | WOS:000266605100014 |
| Scopus: | 2-s2.0-66349133054 |
| РИНЦ: | 13613616 |
| Chemical Abstracts: | 2009:525975 |
| Chemical Abstracts (print): | 151:8599 |
| OpenAlex: | W1968569128 |