C-H versus C-O Addition: A DFT study of the catalytic cleavage of the β-O-4 ether linkage in lignin by iridium and cobalt pincer complexes

Mensah, Mary, Tia, Richard, Adei, Evans and de Leeuw, Nora H. ORCID: https://orcid.org/0000-0002-8271-0545 2023. C-H versus C-O Addition: A DFT study of the catalytic cleavage of the β-O-4 ether linkage in lignin by iridium and cobalt pincer complexes. Catalysts 13 (4) , 757. 10.3390/catal13040757

PDF - Published Version Available under License Creative Commons Attribution. Download (4MB)

Abstract

The potential energy surfaces of the reactions involved in the catalytic cleavage of 2-phenoxy-1-phenylethanol, a model of the β-O-4 linkage in lignin, by (iprPCP)-Ir, (iprPCOP)-Ir, (iprPCP)-Co and (iprPCOP)-Co complexes have been studied using the M06/6-311G**/LANL2TZ level of theory. Both iridium and cobalt are found to be active towards the cleavage of the β-O-4 linkage, with rate constants of 44.7 s−1 and 5.1 × 106 s−1, respectively. The iridium catalysts prefer the ‘initial C-H addition’ pathway, showing a kinetic preference of 16.8 kcal mol−1 over the ‘direct C-O insertion’ pathway, while the cobalt catalysts prefer the ‘direct C-O insertion’ route which is kinetically favored by 15.7 kcal mol−1 over the ‘initial C-H addition’ pathway. A two-state reactivity occurs along the preferred pathway for the cobalt-catalyzed reaction.

Item Type:	Article
Date Type:	Published Online
Status:	Published
Schools:	Advanced Research Computing @ Cardiff (ARCCA) Chemistry
Additional Information:	License information from Publisher: LICENSE 1: URL: https://creativecommons.org/licenses/by/4.0/, Type: open-access
Publisher:	MDPI
ISSN:	2073-4344
Date of First Compliant Deposit:	9 May 2023
Date of Acceptance:	12 April 2023
Last Modified:	02 Aug 2024 08:31
URI:	https://orca.cardiff.ac.uk/id/eprint/159316

Citation Data

Cited 1 time in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item