Document Type
Article
Publication Date
9-1-2025
Abstract
Organic peroxy (ROO•) and hydroperoxy (•QOOH) radicals are key reactive intermediates that are formed via the oxidation of volatile organic compounds during combustion or in the Earth’s atmosphere. Their primary fate is continued unimolecular decay or bimolecular chemistry, the relative branching for which is heavily structure- and temperature-dependent. This article outlines a combined single- and multi-reference quantum chemical study to characterize the near-UV accessible electronically excited states of the prototypical ROO• and •QOOH intermediates, tert-butyl peroxy and hydroperoxy-tert-butyl radicals—the ground-state chemistries of which have been well studied both experimentally and computationally. Additionally, we simulate the electronic absorption profiles of these ROO• and •QOOH intermediates with a variety of multi- and single-reference methods. The results show an interesting conformer dependence on the electronically excited-state character and electronic absorption maxima of •QOOH. The results show promise for electronic absorption spectroscopy to be used as a selected probe for determining •QOOH conformers. Additionally, electronic absorption may contribute to the daytime removal of long-lived •QOOH intermediates formed in the troposphere. We expect that our studies will motivate experiments on the electronic absorption spectra of experimentally achievable ROO• and •QOOH.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Guidry, L. M., Guidry, S. E., Barua, T., Marchetti, B., Vansco, M. F., & Karsili, T. N. V. (2025). Characterizing the Excited States and Electronic Absorption Spectra of Small Alkylperoxy (RO2•) and Hydroperoxy (•QOOH) Radicals. Photochem, 5(3), 26. https://doi.org/10.3390/photochem5030026. Available at https://digitalcommons.coastal.edu/chemistry/
Comments
MDPI originally published this article.