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Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
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Automatization of Atmospheric OH Radical Abstraction Reactions
Daniel Ayoubi1, Galib Hasan1, Luís P Viegas2
1Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark.
The Journal of Physical Chemistry. A
|January 16, 2026
Summary
The Jammy Key for Transition States (JKTS) tool accurately predicts atmospheric volatile organic compound (VOC) reaction rates. This automated method aids in understanding VOC oxidation mechanisms and atmospheric chemistry.
Area of Science:
- Atmospheric Chemistry
- Computational Chemistry
- Chemical Kinetics
Background:
- Atmospheric volatile organic compounds (VOCs) undergo complex reactions with radicals.
- Accurate kinetic data is crucial for modeling atmospheric chemistry.
- Existing computational tools struggle with the vast number of organic species.
Purpose of the Study:
- To develop and validate the Jammy Key for Transition States (JKTS) automated tool.
- To investigate gas-phase hydrogen abstraction reaction kinetics of atmospheric VOCs.
- To compute rate constants for OH-initiated reactions with short-chain compounds and pinonaldehyde.
Main Methods:
- Utilized multiconformer transition state theory (MC-TST).
- Employed Wigner and Eckart tunnelling corrections for accurate rate predictions.
- Computationally determined rate constants and compared them with experimental data.
Main Results:
- JKTS achieved rate constants within a factor of ~2-3 of experimental data.
- Pinonaldehyde branching ratios indicated significant aldehydic and tertiary hydrogen abstraction.
- Calculated pinonaldehyde rate constants closely matched experimental values at room temperature.
Conclusions:
- JKTS demonstrates capability in automating reaction kinetics computation.
- The tool supports accurate atmospheric chemistry modeling of VOC oxidation.
- Validated computational approach for atmospheric radical reaction studies.
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