Vanadium-Based Pro-Catalysts Bearing Depleted 1,3-Calix[4]arenes for Ethylene or ε-Caprolactone Polymerization

Clowes, L, Redshaw, C and Hughes, DL (2011) Vanadium-Based Pro-Catalysts Bearing Depleted 1,3-Calix[4]arenes for Ethylene or ε-Caprolactone Polymerization. Inorganic Chemistry. p. 110712105707054. ISSN 0020-1669

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Abstract

Reaction of [V(X)(OR)3] (X = O, Np-tolyl, R = nPr, tBu) with 5,11,17,23-tBu-25,27-dihydroxycalix[4]arene (LH2) led to the formation of [V(X)(OR)L]2 X = O, R = nPr ( 1 ); X = Np-tolyl, R = nPr ( 2 ); X = Np-tolyl, R = tBu ( 3 ) as the major product. In the case of X = O, the minor hydrolysis product {[VO(OnPr)]2(µ-O)L}2 ( 4 ) has also been characterized. Complexes ( 1 )–( 4) , in the presence of the co-catalyst dimethylaluminum chloride and the reactivator ethyltrichloroacetate, are highly active (=16,400 g/mmol h bar), thermally stable pro-catalysts for the polymerization of ethylene. The use of silica supports with ( 1 ) and ( 2 ) under slurry conditions yielded polymer with activities =30 g/mmol h. Complexes ( 1 )–( 3 ) have also been screened as pro-catalysts for the ring-opening polymerization of e-caprolactone; the conversion rate order ( 1 ) (94%) > ( 2 ) (46%) > ( 3 ) (20%) was observed at 80 °C over 72 h.

Item Type: Article
Faculty \ School: Faculty of Science > School of Chemistry
Related URLs:
Depositing User: Rachel Smith
Date Deposited: 21 Jul 2011 10:18
Last Modified: 21 Apr 2020 16:43
URI: https://ueaeprints.uea.ac.uk/id/eprint/34017
DOI: 10.1021/ic2010198

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