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Vijayakumar S, Wilmouth DM. Kinetics of the Reactions of Chlorinated Very Short-Lived Substances (VSLSs) with Chlorine Atoms. J Phys Chem A 2023; 127:7284-7294. [PMID: 37595126 DOI: 10.1021/acs.jpca.3c02200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
Chlorinated very short-lived substances (VSLSs), which are not controlled by the Montreal Protocol, are of current concern with regard to recovery of stratospheric ozone. Further study is needed on the temperature dependences of chlorinated VSLSs relevant to atmospheric conditions. Here, the kinetics of chlorinated VSLSs, such as chloroform (CHCl3), dichloromethane (CH2Cl2), dichloroethane (CH2ClCH2Cl), and trichloroethene (C2HCl3) reacting with chlorine atoms, were investigated between 180 and 400 K, expanding the range of temperatures relative to previous studies. RRKM/Master Equation and Canonical Variational Transition State Theory were utilized to calculate the rate coefficients using the MultiWell suite of programs. CCSD(T), QCISD(T), and M062X with aug-cc-pV(T+d)Z levels of theory were used to calculate the kinetic parameters. Arrhenius equations obtained from fits to the calculated rate coefficients are k1 = (2.66 ± 0.7) × 10-12 exp [(-927 ± 131)/T] cm3 molecule-1 s-1, k2 = (8.99 ± 0.3) × 10-12 exp [(-957 ± 19)/T] cm3 molecule-1 s-1, k3 = (1.51 ± 0.16) × 10-11 exp [(-714 ± 54)/T] cm3 molecule-1 s-1, and k4 = (9.17 ± 1.8) × 10-12 exp [(612 ± 101)/T] cm3 molecule-1 s-1 for the reactions of CHCl3, CH2Cl2, CH2ClCH2Cl, and C2HCl3 with Cl atoms, respectively. The rate coefficients for the reactions of chlorinated VSLSs with Cl atoms from this study are compared with the most recent recommended values from the NASA/JPL and IUPAC evaluations and with literature values. The reactivity trends of the reactions are discussed.
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Affiliation(s)
- S Vijayakumar
- Harvard John A. Paulson School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 United States
| | - David M Wilmouth
- Harvard John A. Paulson School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 United States
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Sulbaek Andersen MP, Volkova A, Hass SA, Lengkong JW, Hovanessian D, Sølling TI, Wallington TJ, Nielsen OJ. Atmospheric chemistry of ( Z)- and ( E)-1,2-dichloroethene: kinetics and mechanisms of the reactions with Cl atoms, OH radicals, and O 3. Phys Chem Chem Phys 2022; 24:7356-7373. [PMID: 35266471 DOI: 10.1039/d1cp04877e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Smog chambers interfaced with in situ FT-IR detection were used to investigate the kinetics and mechanisms of the Cl atom, OH radical, and O3 initiated oxidation of (Z)- and (E)-1,2-dichloroethene (CHClCHCl) under atmospheric conditions. Relative and absolute rate methods were used to measure k(Cl + (Z)-CHClCHCl) = (8.80 ± 1.75) × 10-11, k(Cl + (E)-CHClCHCl) = (8.51 ± 1.69) × 10-11, k(OH + (Z)-CHClCHCl) = (2.02 ± 0.43) × 10-12, k(OH + (E)-CHClCHCl) = (1.94 ± 0.43) × 10-12, k(O3 + (Z)-CHClCHCl) = (4.50 ± 0.45) × 10-21, and k(O3 + (E)-CHClCHCl) = (1.02 ± 0.10) × 10-19 cm3 molecule-1 s-1 in 700 Torr of N2/air diluent at 298 ± 2 K. Pressure dependencies for the Cl atom reaction kinetics were observed for both isomers, consistent with isomerization occurring via Cl atom elimination from the chemically activated CHCl-CHCl-Cl adduct. The observed products from Cl initiated oxidation were HC(O)Cl (117-133%), CHCl2CHO (29-30%), and the corresponding CHClCHCl isomer (11-20%). OH radical initiated oxidation gives HC(O)Cl as a major product. For reaction of OH with (E)-CHClCHCl, (Z)-CHClCHCl was also observed as a product. A significant chlorine atom elimination channel was observed experimentally (HCl yield) and supported by computational results. Photochemical ozone creation potentials of 12 and 11 were estimated for (Z)- and (E)-CHClCHCl, respectively. Finally, an empirical kinetic relationship is explored for the addition of OH radicals or Cl atoms to small alkenes. The results are discussed in the context of the atmospheric chemistry of (Z)- and (E)-CHClCHCl.
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Affiliation(s)
- Mads P Sulbaek Andersen
- Department of Chemistry and Biochemistry, California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330-8262, USA.
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Aleksandra Volkova
- Department of Chemistry and Biochemistry, California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330-8262, USA.
| | - Sofie A Hass
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Jonathan W Lengkong
- Department of Chemistry and Biochemistry, California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330-8262, USA.
| | - Dvien Hovanessian
- Department of Chemistry and Biochemistry, California State University Northridge, 18111 Nordhoff St., Northridge, CA 91330-8262, USA.
| | - Theis I Sølling
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
- Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Kingdom of Saudi Arabia
| | - Timothy J Wallington
- Research & Advanced Engineering, Ford Motor Company, Dearborn, MI 48121-2053, USA
| | - Ole J Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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Herath TN, Orozco I, Clinch EC, Marshall P. Relative Rate Studies of the Reactions of Atomic Chlorine with Acetone and Cyclic Ketones. INT J CHEM KINET 2017. [DOI: 10.1002/kin.21138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Thushani N. Herath
- Department of Chemistry; University of North Texas; Denton TX 76203-5070
| | - Ivan Orozco
- Department of Chemistry; University of North Texas; Denton TX 76203-5070
| | - Eric C. Clinch
- Department of Chemistry; University of North Texas; Denton TX 76203-5070
| | - Paul Marshall
- Department of Chemistry; University of North Texas; Denton TX 76203-5070
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