Jump to main content
Jump to site search

Issue 40, 2020
Previous Article Next Article

Thermochemical unification of molecular descriptors to predict radical hydrogen abstraction with low computational cost

Author affiliations

Abstract

Chemistry describes transformation of matter with reaction equations and corresponding rate constants. However, accurate rate constants are not always easy to get. Here we focus on radical oxidation reactions. Analysis of over 500 published rate constants of hydroxyl radicals led us to hypothesize that a modified linear free-energy relationship (LFER) could be used to predict rate constants speedily, reliably and accurately. LFERs correlate the Gibbs activation-energy with the Gibbs energy of reaction. We calculated the latter as the sum of one-electron transfer and, if appropriate, proton transfer. We parametrized specific transition state effects to orbital delocalizability and the polarity of the reactant. The calculation time for 500 reactions is less than 8 hours on a standard desktop-PC. Rate constants were also calculated for hydrogen and methyl radicals; these controls show that the predictions are applicable to a broader set of oxidizing radicals. An accuracy of 30–40% (standard deviation) with reference to reported experimental values was found suitable for the screening of complex chemical systems for possibly relevant reactions. In particular, potentially relevant reactions can be singled out and scrutinized in detail when prioritizing chemicals for environmental risk assessment.

Graphical abstract: Thermochemical unification of molecular descriptors to predict radical hydrogen abstraction with low computational cost

Back to tab navigation

Supplementary files

Article information


Submitted
14 Jul 2020
Accepted
22 Sep 2020
First published
23 Sep 2020

This article is Open Access

Phys. Chem. Chem. Phys., 2020,22, 23215-23225
Article type
Paper

Thermochemical unification of molecular descriptors to predict radical hydrogen abstraction with low computational cost

T. M. Nolte, T. Nauser, L. Gubler, A. J. Hendriks and W. J. G. M. Peijnenburg, Phys. Chem. Chem. Phys., 2020, 22, 23215
DOI: 10.1039/D0CP03750H

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

Reproduced material should be attributed as follows:

  • For reproduction of material from NJC:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
  • For reproduction of material from PCCP:
    [Original citation] - Published by the PCCP Owner Societies.
  • For reproduction of material from PPS:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
  • For reproduction of material from all other RSC journals:
    [Original citation] - Published by The Royal Society of Chemistry.

Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.


Social activity

Search articles by author

Spotlight

Advertisements