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Ring opening polymerization of lactides and lactones by multimetallic alkyl zinc complexes derived from the acids Ph₂C(X)CO₂2H (X = OH, NH₂ )

Al-Khafaji, Yahya F.; Elsegood, Mark R. J.; Frese, Josef W. A.; Elsegood, Mark R.J.; Frese, Josef W.A.; Al-Khafaji, Yahya; Redshaw, Carl; Elsegood, Mark; Frese, Josef

Authors

Yahya F. Al-Khafaji

Mark R. J. Elsegood

Josef W. A. Frese

Mark R.J. Elsegood

Josef W.A. Frese

Yahya Al-Khafaji

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Professor Carl Redshaw C.Redshaw@hull.ac.uk
Professor of Inorganic Materials Chemistry and REF Lead for Chemistry

Mark Elsegood

Josef Frese



Abstract

The reaction of the dialkylzinc reagents R₂Zn with the acids 2,2-Ph₂C(X)(CO₂H), where X = NH₂, OH, i.e. 2,2′-diphenylglycine (dpgH) or benzilic acid (benzH2), in toluene at reflux temperature afforded the tetra-nuclear ring complexes [RZn(dpg)]₄, where R = Me (1), Et (2), 2-CF₃C₆H₄ (3), and 2,4,6-F₃C₆H₂ (4); complex 2 has been previously reported. The crystal structures of 1·(2MeCN), 3 and 4·(4(C₇H₈)·1.59(H₂O)) are reported, along with that of the intermediate compound (2-CF₃C₆H₄)3B·MeCN and the known compound [ZnCl₂(NCMe)₂]. Complexes 1–4, together with the known complex [(ZnEt)₃(ZnL)₃(benz)₃] (5; L = MeCN), have been screened, in the absence of benzyl alcohol, for their potential to act as catalysts for the ring opening polymerization (ROP) of ε-caprolactone (ε-CL), δ-valerolactone (δ-VL) and rac-lactide (rac-LA); the co-polymerization of ε-CL with rac-LA was also studied. Complexes 3 and 4 bearing fluorinated aryls at zinc were found to afford the highest activities.

Citation

Al-Khafaji, Y. F., Elsegood, M. R. J., Frese, J. W. A., Elsegood, M. R., Frese, J. W., Al-Khafaji, Y., …Frese, J. (2017). Ring opening polymerization of lactides and lactones by multimetallic alkyl zinc complexes derived from the acids Ph₂C(X)CO₂2H (X = OH, NH₂ ). RSC advances, 7(8), 4510-4517. https://doi.org/10.1039/C6RA26746G

Journal Article Type Article
Acceptance Date Dec 19, 2016
Publication Date Jan 1, 2017
Deposit Date May 9, 2017
Publicly Available Date May 9, 2017
Journal RSC advances
Print ISSN 2046-2069
Electronic ISSN 2046-2069
Publisher Royal Society of Chemistry
Peer Reviewed Peer Reviewed
Volume 7
Issue 8
Pages 4510-4517
DOI https://doi.org/10.1039/C6RA26746G
Keywords Polymerization, Lactides, Lactones
Public URL https://hull-repository.worktribe.com/output/451206
Publisher URL http://pubs.rsc.org/en/Content/ArticleLanding/2017/RA/C6RA26746G#!divAbstract
Additional Information : This document is Similarity Check deposited; : Supplementary Information; : Crystal Structure Data; : Mark R. J. Elsegood (ORCID); : Carl Redshaw (ORCID); : The Royal Society of Chemistry has an exclusive publication licence for this journal; OPEN ACCESS: This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0); : Single-blind; : Received 13 November 2016; Accepted 19 December 2016; Version of Record published 16 January 2017