Douglas, KM orcid.org/0000-0002-3281-3685, Blitz, MA, Mangan, TP orcid.org/0000-0001-7053-5594 et al. (2 more authors) (2020) Kinetic Study of the Reactions PO + O2 and PO2 + O3 and Spectroscopy of the PO Radical. The Journal of Physical Chemistry A. ISSN 1089-5639
Abstract
The kinetics of the reactions of PO with O2 and PO2 with O3 were studied at temperatures ranging from ~ 190 to 340 K, using a pulsed laser photolysis-laser induced fluorescence technique. For the reaction of PO + O2 there is evidence of both a two- and three-body exit channel, producing PO2 + O and PO3, respectively. Potential energy surfaces of both the PO + O2 and PO2 + O3 systems were calculated using electronic structure theory, and combined with RRKM calculations to explain the observed pressure and temperature dependences. For PO + O2, at pressures typical of a planetary upper atmosphere where meteoric ablation of P will occur, the reaction is effectively pressure independent with a yield of PO2 + O of > 99%; the rate coefficient can be expressed by: log10(k, 120 – 500 K, cm3 molecule-1 s-1) = -13.915 + 2.470log10(T) - 0.5020(log10(T))2, with an uncertainty of ± 10 % over the experimental temperature range (191 – 339 K). With increasing pressure, the yield of PO3 increases, reaching ~ 90% at a pressure of 1 atm and T = 300 K. For PO2 + O3, k(188 – 339 K) = 3.7 × 10-11 exp(-1131/T) cm3 molecule-1 s-1, with an uncertainty of ± 26 % over the stated temperature range. Laser induced fluorescence spectra of PO over the wavelength range of 245 – 248 nm were collected and simulated using PGOPHER to obtain new spectroscopic constants for the ground and v = 1 vibrational levels of the X2Π and A2Σ+ states of PO.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 American Chemical Society. This is an author produced version of a journal article published in The Journal of Physical Chemistry A. Uploaded in accordance with the publisher's self-archiving policy. |
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) |
Funding Information: | Funder Grant number PPARC (Particle Physics and Astronomy Research Council) ST/P000517/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Sep 2020 16:07 |
Last Modified: | 02 Sep 2021 00:38 |
Status: | Published online |
Publisher: | American Chemical Society (ACS) |
Identification Number: | 10.1021/acs.jpca.0c06106 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:165257 |