Vanadium(III) phenoxyimine complexes for ethylene or ε-caprolactone polymerization: Mononuclear versus binuclear pre-catalysts

Clowes, Lucy; Walton, Mark; Redshaw, Carl; Chao, Yimin; Walton, Alex; Elo, Pertti; Sumerin, Victor; Hughes, David L.

Abstract

The mononuclear {[C6H4NCH(ArO)]2VCl(THF)} (Ar = 2,4-t-Bu2C6H2 (1), Ar = C 6H4 (2)), {O[C6H4NCH(ArO)] 2}VCl(THF) (Ar = 2,4-t-Bu2C6H2 (3), Ar = C6H4 (4)) and the binuclear vanadium(iii) complexes {[C6H4NCH(ArO)]VCl2(THF)2} 2(μ-CH2CH2) (Ar = 2,4-t-Bu2C 6H2 (5), Ar = C6H4 (6)), have been synthesized and fully characterized. The compounds [C6H 5NCH(ArO)]VCl2(THF)2 (Ar = 2,4-t-Bu 2C6H2 (7), Ar = C6H4 (8)), [2,4,6-Me3-C6H2NCH(ArO)]VCl2 (Ar = 2,4-t-Bu2C6H2 (9), Ar = C 6H4 (10)) and [2,6-i-Pr2-C6H 3NCH(ArO)]VCl2(THF)2 (Ar = 2,4-t-Bu 2C6H2 (11), Ar = C6H4 (12)), {μ-CH2CH2[NCH(C6H4O)] 2VCl(THF)} (14) and {C6H4[NCH(C 6H4O)]2VCl(THF)} (15) were synthesized for comparative polymerization studies. The dizwitterionic compound [2,6-i-Pr 2-C6H3N+(H)CH(C6H 4O)]2VCl2O (13) was also isolated, and presumably formed via a fortuitous hydrolysis reaction. The complexes 2, 5 and 13 have been structurally characterized; the molecular structure of the parent ligand (L5) in 5 is also reported. All complexes have been screened for ethylene as well as ε-caprolactone polymerization, and results are compared against those for known related mono- and bi-nuclear counterparts to evaluate for possible cooperative effects. The compounds 10 and 12 have been supported on modified SiO2, analysed by XPS and subjected to homo-polymerization (ethylene) and co-polymerization (1-hexene and ethylene) studies. © The Royal Society of Chemistry 2013.

Citation

Clowes, L., Walton, M., Redshaw, C., Chao, Y., Walton, A., Elo, P., Sumerin, V., & Hughes, D. L. (2013). Vanadium(III) phenoxyimine complexes for ethylene or ε-caprolactone polymerization: Mononuclear versus binuclear pre-catalysts. Catalysis science & technology, 3(1), 152-160. https://doi.org/10.1039/c2cy20571h

• Journal Article Type: Article
• Acceptance Date: Sep 1, 2012
• Online Publication Date: Sep 4, 2012
• Publication Date: 2013
• Deposit Date: Jun 8, 2022
• Journal: Catalysis Science and Technology
• Print ISSN: 2044-4753
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Issue: 1
• Pages: 152-160
• DOI: https://doi.org/10.1039/c2cy20571h
• Public URL: https://hull-repository.worktribe.com/output/3622122