DFT Study of Ethylene Polymerization by Zirconocene−Boron Catalytic Systems. Effect of Counterion on the Kinetics and Mechanism of the Process Научная публикация
| Журнал |
Organometallics
ISSN: 0276-7333 , E-ISSN: 1520-6041 |
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| Вых. Данные | Год: 2001, Том: 20, Номер: 25, Страницы: 5375-5393 Страниц : 19 DOI: 10.1021/om010067a | ||
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Реферат:
The effect of counterion on the kinetics and mechanism of ethylene polymerization by the zirconocene−boron catalytic system was examined using the density functional theory approach. A comparative study of three model catalytic species, namely, ethylzirconocene cation, Cp2ZrEt+, and two ion pairs of composition Cp2ZrEt+A- (A- = CH3B(C6F5)3-, B(C6F5) 4-) was carried out. It was shown that the nature of counterion affects mainly the ratio between the most stable β-agostic and nonagostic Cp2ZrEt+A- isomers, the thermodynamic and kinetic characteristics of ethylene addition to the Cp2ZrEt+A- ion pairs, and the chain propagation kinetics. The weaker the nucleophilicity of the counterion, the higher the fraction of the β-agostic isomer, the higher the exotermicity, and the lower the activation barrier to ethylene addition to Cp2ZrEt+A-, and the lower the activation energy of chain propagation. All possible pathways of the interaction between Cp2ZrEt+CH3B(C6F5)3- and ethylene molecule were examined and compared. Among all species of composition Cp2ZrEt+CH3B(C6F5)3-, the nonagostic isomer was found to be the most reactive toward ethylene.
Библиографическая ссылка:
Nifant'ev I.E.
, Ustynyuk L.Y.
, Laikov D.N.
DFT Study of Ethylene Polymerization by Zirconocene−Boron Catalytic Systems. Effect of Counterion on the Kinetics and Mechanism of the Process
Organometallics. 2001. V.20. N25. P.5375-5393. DOI: 10.1021/om010067a WOS Scopus OpenAlex
DFT Study of Ethylene Polymerization by Zirconocene−Boron Catalytic Systems. Effect of Counterion on the Kinetics and Mechanism of the Process
Organometallics. 2001. V.20. N25. P.5375-5393. DOI: 10.1021/om010067a WOS Scopus OpenAlex
Идентификаторы БД:
| Web of science: | WOS:000172602700018 |
| Scopus: | 2-s2.0-0035843060 |
| OpenAlex: | W2051644096 |