2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene

Gao, Rong; Wang, Kefeng; Li, Yan; Wang, Fosong; Sun, Wen Hua; Redshaw, Carl; Bochmann, Manfred

Abstract

A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar = 2,6-Me2C6H3), Co2 (Ar = 2,6-Et2C6H3) and Co7 (Ar = 2,6-Br2C6H3) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters.

Citation

Gao, R., Wang, K., Li, Y., Wang, F., Sun, W. H., Redshaw, C., & Bochmann, M. (2009). 2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene. Journal of Molecular Catalysis A: Chemical, 309(1-2), 166-171. https://doi.org/10.1016/j.molcata.2009.05.021

• Journal Article Type: Article
• Acceptance Date: May 27, 2009
• Online Publication Date: Jun 9, 2009
• Publication Date: Aug 18, 2009
• Deposit Date: Jun 8, 2022
• Journal: Journal of Molecular Catalysis A: Chemical
• Print ISSN: 1381-1169
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 309
• Issue: 1-2
• Pages: 166-171
• DOI: https://doi.org/10.1016/j.molcata.2009.05.021
• Public URL: https://hull-repository.worktribe.com/output/3622535