McKee, K, Blitz, MA and Pilling, MJ (2016) Temperature and Pressure Studies of the Reactions of CH3O2, HO2, and 1,2-C4H9O2 with NO2. Journal of Physical Chemistry A, 120 (9). pp. 1408-1420. ISSN 1089-5639
Abstract
A novel technique has been developed for the detection of peroxy radicals in order to study their kinetics with NO2. Peroxy radicals (RO2, where R = H, CH3, and 1,2-C4H9) were produced by laser flash photolysis and were probed by photodissociation of the RO2 and the subsequent detection of either OH or CH3O photofragments by laser-induced fluorescence. Reaction 1, CH3O2 + NO2 + M ⇌ CH3O2NO2 + M (M = N2), was studied between 25 and 400 Torr at 295 K, giving results in excellent agreement with the literature. At temperatures between 333 and 363 K, equilibration was observed and yielded ΔrH⊖298(1) = −93.5 ± 0.3 kJ mol–1. Reaction 2, HO2 + NO2 + M ⇌ HO2NO2 + M (M = N2), was studied at 295 K and showed kinetics in fair agreement with the literature. Equilibration at higher temperatures was obscured by an additional loss of HO2NO2 from the system. In addition, the OH quantum yield from photolysis of HO2NO2 at 248 nm was determined to be 0.15 ± 0.03. Reaction 3, 1,2-C4H9O2 + NO2 + M ⇌ 1,2-C4H9O2NO2 + M (M = He), was studied between 241 and 341 K, and at the higher temperatures equilibration was observed, which yielded ΔrH⊖298(3) = −93.5 ± 0.6 kJ mol–1. The low uncertainties in the enthalpies of formation for both CH3O2 and 1,2-C4H9O2 are a result of using a master equation method that allows global analysis of all the available rate data (present measurements and literature values) for forward and reverse reactions under all conditions of temperature and pressure.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2015, American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry A, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.jpca.5b06306 |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Nov 2015 11:50 |
Last Modified: | 25 Oct 2016 03:18 |
Published Version: | http://dx.doi.org/10.1021/acs.jpca.5b06306 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.jpca.5b06306 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:91542 |