Vanadium Olefin Polymerization Catalysts: NMR Spectroscopic Characterization of V(III) Intermediates
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Journal of Organometallic Chemistry
ISSN: 0022-328X
|
| Output data |
Year: 2018,
Volume: 867,
Pages: 4-13
Pages count
: 10
DOI:
10.1016/j.jorganchem.2017.08.020
|
| Tags |
Active species, Bis(imino)pyridine, Ethylene polymerization, NMR, Vanadium, α-diimine |
| Authors |
Soshnikov Igor E.
1,2
,
Semikolenova Nina V.
1
,
Bryliakov Konstantin P.
1,2
,
Zakharov Vladimir A.
1,2
,
Talsi Evgenii P.
1,2
|
| Affiliations |
| 1 |
Federal Agency for Scientific Organizations, Siberian Branch of the Russian Academy of Sciences, Boreskov Institute of Catalysis, 630090, Novosibirsk, Pr. Lavrentieva, 5, Russian Federation
|
| 2 |
The Ministry of Education and Science of the Russian Federation, Novosibirsk State University, 630090, Novosibirsk, Pirogova Street, 2, Russian Federation
|
|
Funding (2)
|
1
|
Russian Foundation for Basic Research
|
16-03-00236
|
|
2
|
Federal Agency for Scientific Organizations
|
0303-2016-0009
|
Vanadium(III) species formed upon reacting α-diimine (1) and bis(imino)pyridine (5) vananadium(III) pre-catalysts with MAO, AlMe2Cl, AlMe2Cl/[Ph3C][B(C6F5)4], and AlMe3/[Ph3C][B(C6F5)4] have been characterized in detail by 1H, 2H, and 19F NMR spectroscopy; the VIII-CH3 moiety has been observed by 1H and 2H NMR spectroscopy. For complex 1, zwitterion-like species [L′VIIIR2+···MeMAO−] and ion pairs [L′VIIIR2(THF)2]+[A]- (L′ = 1,4-bis-3,5-dimethylphenyl-2,3-dimethyl-1,4-diazabuta-1,3-diene; [A]− = [MeMAO]− or [B(C6F5)4]−) have been identified. The outer-sphere ion pairs of the type [L(Cl)VIII(μ-Cl)2AlMe2]+[A]−, [L(Me)VIII(μ-Cl)2AlMe2]+[A]−, [LVIIICl2(THF)]+[A]− and [LVIII(Cl)Me(THF)]+[A]− (L = 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine; [A]− = [AlMe3Cl]− or [B(C6F5)4]−) have been found in the systems based on the complex 5. The nature of the vanadium species active in ethylene polymerization and the catalyst deactivation pathways are discussed.