Atmospheric Chemistry of Tetrahydrofuran, 2-Methyltetrahydrofuran, and 2,5-Dimethyltetrahydrofuran: Kinetics of Reactions with Chlorine Atoms, OD Radicals, and Ozone

Christina Andersen; Ole John Nielsen; Freja F Østerstrøm; Stina Ausmeel; Elna J K Nilsson; Mads P Sulbaek Andersen

doi:10.1021/acs.jpca.6b06618

Atmospheric Chemistry of Tetrahydrofuran, 2-Methyltetrahydrofuran, and 2,5-Dimethyltetrahydrofuran: Kinetics of Reactions with Chlorine Atoms, OD Radicals, and Ozone

J Phys Chem A. 2016 Sep 22;120(37):7320-6. doi: 10.1021/acs.jpca.6b06618. Epub 2016 Sep 7.

Authors

Christina Andersen¹, Ole John Nielsen¹, Freja F Østerstrøm¹, Stina Ausmeel², Elna J K Nilsson², Mads P Sulbaek Andersen^{1

3}

Affiliations

¹ Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , Universitetsparken 5, 2100 Copenhagen, Denmark.
² Combustion Physics, Lund University , Professorgatan 1 SE-221 00, Lund, Sweden.
³ Department of Chemistry and Biochemistry, California State University Northridge , 18111 Nordhoff Street, Northridge, California 91330-8262, United States.

PMID: 27556743
DOI: 10.1021/acs.jpca.6b06618

Abstract

FTIR smog chamber techniques were used to study the kinetics of the gas-phase reactions of Cl atoms, OD radicals, and O3 with the five-membered ring-structured compounds tetrahydrofuran (C4H8O, THF), 2-methyltetrahydrofuran (CH3C4H7O, 2-MTHF), 2,5-dimethyltetrahydrofuran ((CH3)2C4H5O, 2,5-DMTHF), and furan (C4H4O). The rate coefficients determined using relative rate methods were kTHF+Cl = (1.96 ± 0.24) × 10(-10), kTHF+OD = (1.81 ± 0.27) × 10(-11), kTHF+O3 = (6.41 ± 2.90) × 10(-21), k2-MTHF+Cl = (2.65 ± 0.43) × 10(-10), k2-MTHF+OD = (2.41 ± 0.51) × 10(-11), k2-MTHF+O3 = (1.87 ± 0.82) × 10(-20), k2,5-DMTHF+OD = (4.56 ± 0.68) × 10(-11), k2,5-DMTHF+Cl = (2.84 ± 0.34) × 10(-10), k2,5-DMTHF+O3 = (4.58 ± 2.18), kfuran+Cl = (2.39 ± 0.27) × 10(-10), and kfuran+O3 = (2.60 ± 0.31) × 10(-18) molecules cm(-3) s(-1). Rate coefficients of the reactions with ozone were also determined using the absolute rate method under pseudo-first-order conditions. OD radicals, in place of OH radicals, were produced from CD3ONO to avoid spectral overlap of isopropyl and methyl nitrite with the reactants. The kinetics of OD radical reactions are expected to resemble the kinetics of OH radical reactions, and the rate coefficients of the reactions with OD radicals were used to calculate the atmospheric lifetimes with respect to reactions with OH radicals. The lifetimes of THF, 2-MTHF, and 2,5-DMTHF are approximately 15, 12, and 6 h, respectively.