Formation and Evolution of Chain-Propagating Species Upon Ethylene Polymerization with Neutral Salicylaldiminato Nickel(II) Catalysts | Sciact - CRIS-система Института катализа

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

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	Institute of Catalysis, Pr. Lavrentieva 5 630090 Novosibirsk (Russian Federation)
2	University of Konstanz, Chair of Chemical Material Science, Department of Chemistry, Universittstrasse 10, 78457 Konstanz (Germany)

Информация о финансировании (3)

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

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.

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 CAPlusCA OpenAlex

Полный текст от издателя

Поступила в редакцию:	18 мар. 2013 г.
Опубликована online:	10 июл. 2013 г.
Опубликована в печати:	19 авг. 2013 г.

Web of science:	WOS:000323098100040
Scopus:	2-s2.0-84882280775
РИНЦ:	20458078
Chemical Abstracts:	2013:1102558
Chemical Abstracts (print):	160:53841
OpenAlex:	W2138591240

БД	Цитирований
Web of science	14
Scopus	15
РИНЦ	14
OpenAlex	15