Four Isotope-Labeled Recombination Pathways of Ozone Formation
A theoretical approach is developed for the description of all possible recombination pathways in the ozone forming reaction, without neglecting any process a priori, and without decoupling the individual pathways one from another. These pathways become physically distinct when a rare isotope of oxygen is introduced, such as 18O, which represents a sensitive probe of the ozone forming reaction. Each isotopologue of O3 contains 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-difference. 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. Altogether, the distribution of lifetimes is found to be very similar for the metastable states in symmetric and asymmetric ozone isotopomers.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- National Science Found (NSF); USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1807875
- Report Number(s):
- LA-UR--21-20550
- Journal Information:
- Molecules, Journal Name: Molecules Journal Issue: 5 Vol. 26; ISSN 1420-3049
- Publisher:
- MDPICopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Several Levels of Theory for Description of Isotope Effects in Ozone: Symmetry Effect and Mass Effect
The ratio of the number of states in asymmetric and symmetric ozone molecules deviates from the statistical value of 2