Douglas, K.M. orcid.org/0000-0002-3281-3685, Lucas, D. orcid.org/0000-0002-1841-2076, Walsh, C. orcid.org/0000-0001-6078-786X et al. (2 more authors) (2023) Experimental and Theoretical Investigation of the Reaction of NH2 with NO at Very Low Temperatures. The Journal of Physical Chemistry A, 127 (34). pp. 7205-7215. ISSN 1089-5639
Abstract
The first experimental study of the low-temperature kinetics of the gas-phase reaction between NH2 and NO has been performed. A pulsed laser photolysis-laser-induced fluorescence technique was used to create and monitor the temporal decay of NH2 in the presence of NO. Measurements were carried out over the temperature range of 24–106 K, with the low temperatures achieved using a pulsed Laval nozzle expansion. The negative temperature dependence of the reaction rate coefficient observed at higher temperatures in the literature continues at these lower temperatures, with the rate coefficient reaching 3.5 × 10–10 cm3 molecule–1 s–1 at T = 26 K. Ab initio calculations of the potential energy surface were combined with rate theory calculations using the MESMER software package in order to calculate and predict rate coefficients and branching ratios over a wide range of temperatures, which are largely consistent with experimentally determined literature values. These theoretical calculations indicate that at the low temperatures investigated for this reaction, only one product channel producing N2 + H2O is important. The rate coefficients determined in this study were used in a gas-phase astrochemical model. Models were run over a range of physical conditions appropriate for cold to warm molecular clouds (10 to 30 K; 104 to 106 cm–3), resulting in only minor changes (<1%) to the abundances of NH2 and NO at steady state. Hence, despite the observed increase in the rate at low temperatures, this mechanism is not a dominant loss mechanism for either NH2 or NO under dark cloud conditions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 25 Aug 2023 11:15 |
Last Modified: | 30 Oct 2023 14:19 |
Published Version: | https://pubs.acs.org/doi/10.1021/acs.jpca.3c03652 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.jpca.3c03652 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:202718 |