An EPR Study of the V(IV) Species Formed Upon Activation of a Vanadyl Phenoxyimine Polymerization Catalyst with AlR3 and AlR2Cl (R ¼ Me, Et)a
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Macromolecular Chemistry and Physics
ISSN: 1022-1352
, E-ISSN: 1521-3935
|
| Output data |
Year: 2009,
Volume: 210,
Number: 7,
Pages: 542-548
Pages count
: 7
DOI:
10.1002/macp.200800556
|
| Tags |
Active species, EPR, Olefin polymerization, Vanadium catalysts |
| Authors |
Soshnikov Igor E.
1,2
,
Semikolenova Nina V.
1
,
Brylyakov Konstantin P.
1,2
,
Shubin Alexander A.
1,2
,
Zakharov Vladimir A.
1
,
Redshaw Carl
3
,
Talsi Evgenii P.
1,2
|
| Affiliations |
| 1 |
Boreskov Institute of Catalysis SB RAS
|
| 2 |
Novosibirsk State University
|
| 3 |
University of East Anglia
|
|
Funding (2)
|
1
|
Russian Foundation for Basic Research
|
06-03-32700
|
|
2
|
Royal Society
|
2006/R4-IJP
|
Vanadium(IV) complexes formed in the systems L2VIVO/AlR3, L2VIVO/AlR3/ETA, L2VIVO/AlR2Cl, and L2VIVO/AlR2Cl/ETA, where L is a phenoxyimine ligand (Scheme 1), R = Me or Et, and ETA is ethyltrichloroacetate, were monitored by EPR. It was shown, that at 20 °C, V(IV) complexes with proposed structures (L′)VIV(O)(R)(AlR3) are formed in the systems L2VIVO/AlR3 and L2VIVO/AlR3/ETA, whereas complexes with proposed structures (L′)VIV(O)(R)(AlR2Cl) are formed in the systems L2VIVO/AlR2Cl and L2VIVO/AlR2Cl/ETA (L′ is the modified initial ligand). The systems L2VIVO/AlR3/ETA are inert towards polymerization of ethylene, whereas the systems L2VIVO/AlR2Cl/ETA are moderately active in this reaction. The polymerization activity of the systems L2VIVO/AlR2Cl/ETA correlates with the concentration of V(IV) species present in the reaction solution. V(IV) complexes of the type (L′)VIV(O)(R)(AlR2Cl) can be precursors of the active species of polymerization.