Abdessamad Arbaoui
Vanadium-based imido-alkoxide pro-catalysts bearing bisphenolate ligands for ethylene and ε-caprolactone polymerisation
Arbaoui, Abdessamad; Redshaw, Carl; Homden, Damien M.; Wright, Joseph A.; Elsegood, Mark R.J.
Authors
Emeritus Professor Carl Redshaw C.Redshaw@hull.ac.uk
Emeritus Professor
Damien M. Homden
Joseph A. Wright
Mark R.J. Elsegood
Abstract
The pro-catalysts [V(NAr)(L)(OR)] (Ar = p-tolyl, p-ClC6H 4, p-(OMe)C6H4, p-(CF3)C 6H4; R = t-Bu, i-Pr, n-Pr, Et, C(CH3)(CF 3)2) have been prepared in good yields from the reaction of [V(NAr)(OR)3] and the bisphenol 2,2′-CH3CH[4,6- (t-Bu)2C6H2OH]2 (LH2). X-Ray crystal structure determinations for the Ar = p-tolyl, R = t-Bu (1), R = C(CH3)(CF3)2 (2) and Ar = p-ClC 6H4, R = t-Bu (3) derivatives revealed monomeric complexes, whereas use of R = i-Pr, n-Pr or Et led to alkoxide-bridged dimeric structures of the form [V(NAr)(L)(μ-OR)]2 (R = i-Pr, Ar = p-tolyl (4), p-ClC6H4 (5), p-(CF3)C6H 4 (6), p-(OMe)C6H4 (7); R = n-Pr, Ar = p-tolyl (8), p-(CF3)C6H4 (9); R = Et, Ar = p-ClC 6H4 (10), p-tolyl (11)). Complexes 1-11 yield highly active ethylene polymerisation catalysts when treated with DMAC (dimethylaluminium chloride) in the presence of ETA (ethyltrichloroacetate), with activities in the range 38800 to 75200 g mmol-1 h-1 bar-1. The molecular weights of the resultant polymers were in the range 37000 to 411000 g mol-1, with molecular weight distribution 2.2 to 4.7. The effect of the nature of the para-arylimido substituent and the alkoxide group OR upon the catalytic activity has been investigated. For ε-caprolactone polymerisation, mononuclear 1-3 exhibit low conversion (≤25%; 0% for 2), whereas use of the dimeric species 4-11 led to higher conversions (41-78%). © 2009 The Royal Society of Chemistry.
Citation
Arbaoui, A., Redshaw, C., Homden, D. M., Wright, J. A., & Elsegood, M. R. (2009). Vanadium-based imido-alkoxide pro-catalysts bearing bisphenolate ligands for ethylene and ε-caprolactone polymerisation. Dalton Transactions : an international journal of inorganic chemistry, 8911-8922. https://doi.org/10.1039/b902402f
Journal Article Type | Article |
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Acceptance Date | May 15, 2009 |
Online Publication Date | Jul 7, 2009 |
Publication Date | Oct 19, 2009 |
Deposit Date | Jun 8, 2022 |
Journal | Dalton Transactions |
Print ISSN | 1477-9226 |
Electronic ISSN | 1477-9234 |
Publisher | Royal Society of Chemistry |
Peer Reviewed | Peer Reviewed |
Issue | 41 |
Pages | 8911-8922 |
DOI | https://doi.org/10.1039/b902402f |
Public URL | https://hull-repository.worktribe.com/output/3622524 |