Isotope-labeled recombination pathways of ozone formation Elizaveta Grushnikova, Igor Gayday and Dmitri Babikov Marquette University, Chemistry Department, USA Theoretical approach is developed for the description of all possible recombination pathways for the Lindemann mechanism of ozone formation, without neglecting any process, and without decoupling the individual pathways one from another. These pathways become physically distinct when a rare isotope of oxygen is introduced, such as 18 O, which represents a sensitive probe of the reaction mechanism. Each isotopologue of ozonecontains two types of physically distinct entrance channels and two types of physically distinct product wells, creating four recombination pathways. Calculations are done for singly and doubly substituted isotopologues of ozone, eight rate coefficients total. Two pathways for the formation of asymmetric ozone isotopomer exhibit rather different rate coefficients, indicating large isotope effect driven by ΔZPE of the two channels. Rate coefficient for the formation of symmetric isotopomer of ozone (third pathway) is found to be in between of those two, while the rate of insertion pathway is smaller by two orders of magnitude. These trends are in good agreement with experiments, for both singly and doubly substituted ozone. The total formation rates for asymmetric isotopomers are found to be somewhat larger than those for symmetric isotopomers, but not as much as in the experiment. Overall, the distribution of lifetimes is found to be very similar for the metastable states in symmetric and asymmetric ozone 1. I. Gayday and D. Babikov, “Efficient method for an approximate treatment of Coriolis effect in the calculations of quantum dynamics and spectroscopy, with application to scattering resonances in ozone”, J. Phys. Chem. A 125, 5661–5669, 2021. 2. I. Gayday, E. Grushnikova and D. Babikov, "Influence of the Coriolis effect on the properties of scattering resonances in symmetric and asymmetric isotopomers of ozone", Phys. Chem. Chem. Phys. 22, 27560 - 27571, 2020. 3. I. Gayday, A. Teplukhin, B. Kendrick and D. Babikov, “On the role of rotation-vibration coupling in the spectra of ozone isotopomers” J. Chem. Phys. 152, 144104 (16 pages), 2020. isotopomers. References
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