Sulfur and phosphorus oxyacid radicals
Abstract
We report a computational study of the little-studied neutral bisulfite, bisulfate, dihydro-phosphite and dihydro–phosphate radicals (HSOx•, H2POx•, x = 3,4), calling special attention to their various tautomeric structures together with pKa values estimated from the Gibbs free energies of their dissociations (at the G4 and CAM-B3LYP levels of density functional theory). The energetics of microhydration clusters with up to 4 water molecules for the S-based species and up to 8 waters for the P-based species were investigated. The number of microhydrating water molecules needed to induce spontaneous de-protonation is found to correlate the acid strength of each radical. According to computed Gibbs free reaction and activation energies, S- and P-centered radicals preferentially add to the double bond of propene (a lipid model), whereas the O-centered radical tautomers prefer H-abstraction. The likely downstream reactions of these radicals in biological media are discussed.
Citation
Buehl , M , Hutson , T , Missio , A & Walton , J C 2022 , ' Sulfur and phosphorus oxyacid radicals ' , Journal of Physical Chemistry A , vol. 126 , no. 5 , pp. 760-771 . https://doi.org/10.1021/acs.jpca.1c10455
Publication
Journal of Physical Chemistry A
Status
Peer reviewed
ISSN
1089-5639Type
Journal article
Rights
Copyright © 2022 American Chemical Society. Open Access article licensed under Creative Commons Attribution CC-BY 4.0.
Description
Authors thank the University of St. Andrews and the EaStCHEM Research Computing Facility for financial and computational support.Collections
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