0509120 - ÚOCHB 2020 RIV US eng J - Journal Article
Bím, Daniel - Maldonado-Domínguez, M. - Fučík, R. - Srnec, M.
Dissecting the Temperature Dependence of Electron-Proton Transfer Reactivity.
Journal of Physical Chemistry C. Roč. 123, č. 35 (2019), s. 21422-21428. ISSN 1932-7447. E-ISSN 1932-7455
Institutional support: RVO:61388963
Keywords : hydrogen-atom transfer * C-H bonds * hydroxylation
OECD category: Physical chemistry
Impact factor: 4.189, year: 2019
Method of publishing: Limited access
https://pubs.acs.org/doi/10.1021/acs.jpcc.9b07375

The rate of elementary reactions usually rises with increasing temperature. In rare cases, however, a slowdown is observed instead. One example of this is hydrogenatom abstraction from the iron(II)-tris[2,2'-bi(tetrahydropyrimidine)] complex, [Fe-II(H(2)bip)(3)](2+), by the TEMPO radical. So far ascribed to a strongly temperature-dependent equilibrium constant K-eq, this description does not fully account for the observed rate deceleration. In this work, we dissect the activation barriers of four electron-proton transfers including this exceptional case, by employing the concept of asynchronicity, derived as an extension to Marcus theory, together with the classical Bell-Evans-Polanyi effect. By also accounting for tunneling and statistics, the presented theoretical model yields near-quantitative accuracy. Based on chemically well-defined quantities, this method offers a detailed insight into temperature-dependent kinetics of hydrogen-atom abstraction reactions and may serve as an alternative to the established Eyring plot analysis.
Permanent Link: http://hdl.handle.net/11104/0299902