Sciact
Toggle navigation
  • EN
  • RU

Разделы:

  • Статьи
  • Книги
  • Доклады на конференциях
  • Тезисы докладов
  • Патенты

Formation and Evolution of Chain-Propagating Species Upon Ethylene Polymerization with Neutral Salicylaldiminato Nickel(II) Catalysts Научная публикация

Общее Язык: Английский, Жанр: Статья (Full article),
Статус опубликования: Опубликована, Оригинальность: Оригинальная
Журнал Chemistry - A European Journal
ISSN: 0947-6539 , E-ISSN: 1521-3765
Вых. Данные Год: 2013, Том: 19, Номер: 34, Страницы: 11409-11417 Страниц : 9 DOI: 10.1002/chem.201301037
Ключевые слова nickel, NMR spectroscopy, polymerization, reaction mechanisms, reactive intermediates
Авторы Soshnikov Igor E. 1 , Semikolenova Nina V. 1 , Zakharov Vladimir A. 1 , Moller Heiko M. 2 , Olscher Franz 2 , Osichow Anna 2 , Gottker-Schnettmann Inigo 2 , Mecking Stefan 2 , Talsi Evgenii P. 1 , Bryliakov Konstantin P. 1
Организации
1 Институт катализа им. Г.К. Борескова СО РАН
2 University of Konstanz

Информация о финансировании (3)

1 Российский фонд фундаментальных исследований 12-03-91159
2 Российский фонд фундаментальных исследований 10-03-91330
3 German Research Foundation Me 1388/9-1

Реферат: Formation of Ni–polymeryl propagating species upon the interaction of three salicylaldiminato nickel(II) complexes of the type [(N,O)Ni(CH3)(Py)] (where (N,O)=salicylaldimine ligands, Py=pyridine) with ethylene (C2H4/Ni=10:30) has been studied by 1H and 13C NMR spectroscopy. Typically, the ethylene/catalyst mixtures in [D8]toluene were stored for short periods of time at +60 °C to generate the [(N,O)Ni(polymeryl)] species, then quickly cooled, and the NMR measurements were conducted at −20 °C. At that temperature, the [(N,O)Ni(polymeryl)] species are stable for days; diffusion 1H NMR measurements provide an estimate of the average length of polymeryl chain (polymeryl=(C2H4)nH, n=6–18). At high ethylene consumptions, the [(N,O)Ni(polymeryl)] intermediates decline, releasing free polymer chains and yielding [(N,O)Ni(Et)(Py)] species, which also further decompose to form the ultimate catalyst degradation product, a paramagnetic [(N,O)2Ni(Py)] complex. In [(N,O)2Ni(Py)], the pyridine ligand is labile (with activation energy for its dissociation of (12.3±0.5) kcal mol−1, ΔH≠298=(11.7±0.5) kcal mol−1, ΔS≠298 =(−7±1) cal K−1 mol−1). Upon the addition of nonpolar solvent (pentane), the pyridine ligand is lost completely to yield the crystals of diamagnetic [(N,O)2Ni] complex. NMR spectroscopic analysis of the polyethylenes formed suggests that the evolution of chain-propagating species ends up with formation of polyethylene with predominately internal and terminal vinylene groups rather than vinyl groups.
Библиографическая ссылка: Soshnikov I.E. , Semikolenova N.V. , Zakharov V.A. , Moller H.M. , Olscher F. , Osichow A. , Gottker-Schnettmann I. , Mecking S. , Talsi E.P. , Bryliakov K.P.
Formation and Evolution of Chain-Propagating Species Upon Ethylene Polymerization with Neutral Salicylaldiminato Nickel(II) Catalysts
Chemistry - A European Journal. 2013. V.19. N34. P.11409-11417. DOI: 10.1002/chem.201301037 WOS Scopus РИНЦ
Файлы: Полный текст от издателя
Даты:
Поступила в редакцию: 18 мар. 2013 г.
Опубликована online: 10 июл. 2013 г.
Опубликована в печати: 19 авг. 2013 г.
Идентификаторы:
Web of science WOS:000323098100040
Scopus 2-s2.0-84882280775
РИНЦ 20458078
Chemical Abstracts 2013:1102558
Chemical Abstracts (print) 160:53841
Альметрики: