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Hata H, Tonokura K. Kinetic study of isoprene hydroxy hydroperoxide radicals reacting with sulphur dioxide and their global-scale impact on sulphate formation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 38856669 DOI: 10.1039/d4em00232f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Isoprene is the most relevant volatile organic compound emitted during the biosynthesis of metabolism processes. The oxidation of isoprene by a hydroxy radical (OH) is one of the main consumption schemes that generate six isomers of isoprene hydroxy hydroperoxide radicals (ISOPOOs). In this study, the rate constants of ISOPOOs + sulphur dioxide (SO2) reactions that eventually generate sulphur trioxide (SO3), the precursor of sulphate aerosol (SO42-(p)), are determined using microcanonical kinetic theories coupled with molecular structures and energies estimated by quantum chemical calculations. The results show that the reaction rates range from 10-27 to 10-20 cm3 molecule-1 s-1, depending on the atmospheric temperature and structure of the six ISOPOO isomers. The effect of SO3 formation from SO2 oxidation by ISOPOOs on the atmosphere is evaluated by a global chemical transport model, along with the rate constants obtained from microcanonical kinetic theories. The results show that SO3 formation is enhanced in regions with high SO2 or low nitrogen oxide (NO), such as China, the Middle East, and Amazon rainforests. However, the production rates of SO3 formation by ISOPOOs + SO2 reactions are eight orders of magnitude lower than that from the OH + SO2 reaction. This is indicative of SO42-(p) formation from the direct oxidation of SO2 by ISOPOOs, which is almost negligible in the atmosphere. The results of this study entail a detailed analysis of SO3 formation from gas-phase reactions of isoprene-derived products.
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Affiliation(s)
- Hiroo Hata
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
| | - Kenichi Tonokura
- Department of Environment Systems, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwano-ha, Kashiwa, Chiba 277-8563, Japan
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2
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Liang M, Dai S, Cheng H, Yu C, Li W, Lai F, Yang K, Ma L, Liu X. Oxidation characteristic and thermal runaway of isoprene. BMC Chem 2023; 17:110. [PMID: 37660031 PMCID: PMC10475201 DOI: 10.1186/s13065-023-01016-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/08/2023] [Indexed: 09/04/2023] Open
Abstract
In this study, the oxidation characteristics of isoprene were investigated using a custom-designed mini closed pressure vessel test (MCPVT). The results show that isoprene is unstable and polymerization occurs under a nitrogen atmosphere. Under an oxygen atmosphere, the oxidation process of isoprene was divided into three stages: (1) isoprene reacts with oxygen to produce peroxide; (2) Peroxides produce free radicals through thermal decomposition; (3) Free radicals cause complex oxidation and thermal runaway reactions. The oxidation of isoprene conforms to the second-order reaction kinetics, and the activation energy was 86.88 kJ·mol-1. The thermal decomposition characteristics of the total oxidation product and purified peroxide mixture were determined by differential scanning calorimetry (DSC). The initial exothermic temperatures Ton were 371.17 K and 365.84 K, respectively. And the decomposition heat QDSC were 816.66 J·g-1 and 991.08 J·g-1, respectively. It indicates that high concentration of isoprene peroxide has a high risk of thermal runaway. The results of thermal runaway experiment showed that the temperature and pressure of isoprene oxidation were prone to rise rapidly, which indicates that the oxidation reaction was dangerous. The reaction products of isoprene were analyzed by gas chromatography-mass spectrometry (GC-MS). The main oxidation products were methyl vinyl ketone, methacrolein, 3-methylfuran, etc. The main thermal runaway products were dimethoxymethane, 2,3-pentanedione, naphthalene, etc. Based on the reaction products, the possible reaction pathway of isoprene was proposed.
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Affiliation(s)
- Min Liang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Suyi Dai
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Haijun Cheng
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Chang Yu
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Weiguang Li
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Fang Lai
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Kang Yang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
| | - Li Ma
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China.
| | - Xiongmin Liu
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China.
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Zhang Z, Wang C, Zhao Y, Zhao Y, Li G, Xie H, Jiang L. Autoxidation Mechanism and Kinetics of Methacrolein in the Atmosphere. J Phys Chem A 2023; 127:2819-2829. [PMID: 36939326 DOI: 10.1021/acs.jpca.3c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Elucidating the autoxidation of volatile organic compounds (VOCs) is crucial to understanding the formation mechanism of secondary organic aerosols, but it has been proven to be challenging due to the complexity of reactions under atmospheric conditions. Here, we report a comprehensive theoretical study of atmospheric autoxidation in VOCs exemplified by the atmospherically important methacrolein (MACR), a major oxidation product of isoprene. The results indicate that the Cl-adducts and H-abstraction products of MACR readily react with O2 and undergo subsequent isomerizations via H-shift and cyclization, forming a large variety of lowly and highly oxygenated organic molecules. In particular, the first- and third-generation oxidation products derived from the Cl-adducts and the methyl-H-abstraction complexes are dominated in the atmospheric autoxidation, for which the fractional yields are remarkably affected by the NO concentration. The present findings have important implications for a systematical understanding of the oxidation processes of isoprene-derived compounds in the atmospheric environments.
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Affiliation(s)
- Zhaoyan Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Chong Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Yingqi Zhao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Ya Zhao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Gang Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Hua Xie
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,Hefei National Laboratory, Hefei 230088, China
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4
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Song M, Liu Y, Li X, Lu S. Advances on Atmospheric Oxidation Mechanism of Typical Aromatic Hydrocarbons. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21050224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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5
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Wennberg PO, Bates KH, Crounse JD, Dodson LG, McVay RC, Mertens LA, Nguyen TB, Praske E, Schwantes RH, Smarte MD, St Clair JM, Teng AP, Zhang X, Seinfeld JH. Gas-Phase Reactions of Isoprene and Its Major Oxidation Products. Chem Rev 2018. [PMID: 29522327 DOI: 10.1021/acs.chemrev.7b00439] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isoprene carries approximately half of the flux of non-methane volatile organic carbon emitted to the atmosphere by the biosphere. Accurate representation of its oxidation rate and products is essential for quantifying its influence on the abundance of the hydroxyl radical (OH), nitrogen oxide free radicals (NO x), ozone (O3), and, via the formation of highly oxygenated compounds, aerosol. We present a review of recent laboratory and theoretical studies of the oxidation pathways of isoprene initiated by addition of OH, O3, the nitrate radical (NO3), and the chlorine atom. From this review, a recommendation for a nearly complete gas-phase oxidation mechanism of isoprene and its major products is developed. The mechanism is compiled with the aims of providing an accurate representation of the flow of carbon while allowing quantification of the impact of isoprene emissions on HO x and NO x free radical concentrations and of the yields of products known to be involved in condensed-phase processes. Finally, a simplified (reduced) mechanism is developed for use in chemical transport models that retains the essential chemistry required to accurately simulate isoprene oxidation under conditions where it occurs in the atmosphere-above forested regions remote from large NO x emissions.
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Nozière B, Hanson DR. Speciated Monitoring of Gas-Phase Organic Peroxy Radicals by Chemical Ionization Mass Spectrometry: Cross-Reactions between CH3O2, CH3(CO)O2, (CH3)3CO2, and c-C6H11O2. J Phys Chem A 2017; 121:8453-8464. [DOI: 10.1021/acs.jpca.7b06456] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Thomas WC, Dresser WD, Cortés DA, Elrod MJ. Gas Phase Oxidation of Campholenic Aldehyde and Solution Phase Reactivity of its Epoxide Derivative. J Phys Chem A 2016; 121:168-180. [PMID: 27936731 DOI: 10.1021/acs.jpca.6b08642] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rate constant for the OH reaction with campholenic aldehyde (CA) was measured using the flow tube-chemical ionization mass spectrometry method with a relative rate kinetics technique and was found to be (6.54 ± 0.52) × 10-11 cm3 molecule-1 s-1 at 100 Torr pressure and 298 K. A mechanism for the formation of the observed products was developed for both NO-free and NO-present conditions. On the basis of measurements of the pressure dependent yields of the products, between 5 and 20% of the CA oxidation at atmospheric pressure is predicted to lead to campholenic aldehyde epoxide (CAE). The aqueous solution reaction rate constants for CAE were determined via NMR spectroscopy and were found to be (2.241 ± 0.036) × 10-5 s-1 for neutral conditions and 0.0989 ± 0.0053 M-1 s-1 for acid-catalyzed conditions at 298 K. The products of the CAE aqueous solution reaction were identified as an isomer of CAE and the aldehyde group hydrated form of this isomer. Unlike the isoprene-derived epoxide, IEPOX, a nucleophilic addition mechanism was not observed. On the basis of the rate constants determined for CA and CAE, it is likely that these species are reactive on atmospherically relevant time scales in the gas and aerosol phases, respectively. The results of the present study largely support a previous supposition that α-pinene-derived secondary organic aerosol may be influenced by the multiphase processing of various intermediate species, including those with epoxide functionality.
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Affiliation(s)
- William C Thomas
- Department of Chemistry and Biochemistry, Oberlin College , Oberlin, Ohio 44074, United States
| | - William D Dresser
- Department of Chemistry and Biochemistry, Oberlin College , Oberlin, Ohio 44074, United States
| | - Diego A Cortés
- Department of Chemistry and Biochemistry, Oberlin College , Oberlin, Ohio 44074, United States
| | - Matthew J Elrod
- Department of Chemistry and Biochemistry, Oberlin College , Oberlin, Ohio 44074, United States
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8
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Nozière B, Kalberer M, Claeys M, Allan J, D'Anna B, Decesari S, Finessi E, Glasius M, Grgić I, Hamilton JF, Hoffmann T, Iinuma Y, Jaoui M, Kahnt A, Kampf CJ, Kourtchev I, Maenhaut W, Marsden N, Saarikoski S, Schnelle-Kreis J, Surratt JD, Szidat S, Szmigielski R, Wisthaler A. The molecular identification of organic compounds in the atmosphere: state of the art and challenges. Chem Rev 2015; 115:3919-83. [PMID: 25647604 DOI: 10.1021/cr5003485] [Citation(s) in RCA: 203] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Barbara Nozière
- †Ircelyon/CNRS and Université Lyon 1, 69626 Villeurbanne Cedex, France
| | | | | | | | - Barbara D'Anna
- †Ircelyon/CNRS and Université Lyon 1, 69626 Villeurbanne Cedex, France
| | | | | | | | - Irena Grgić
- ○National Institute of Chemistry, 1000 Ljubljana, Slovenia
| | | | | | - Yoshiteru Iinuma
- ¶Leibniz-Institut für Troposphärenforschung, 04318 Leipzig, Germany
| | | | | | | | - Ivan Kourtchev
- ‡University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Willy Maenhaut
- §University of Antwerp, 2000 Antwerp, Belgium.,□Ghent University, 9000 Gent, Belgium
| | | | | | | | - Jason D Surratt
- ▼University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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9
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Lee L, Teng AP, Wennberg PO, Crounse JD, Cohen RC. On rates and mechanisms of OH and O3 reactions with isoprene-derived hydroxy nitrates. J Phys Chem A 2014; 118:1622-37. [PMID: 24555928 DOI: 10.1021/jp4107603] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Eight distinct hydroxy nitrates are stable products of the first step in the atmospheric oxidation of isoprene by OH. The subsequent chemical fate of these molecules affects global and regional production of ozone and aerosol as well as the location of nitrogen deposition. We synthesized and purified 3 of the 8 isoprene hydroxy nitrate isomers: (E/Z)-2-methyl-4-nitrooxybut-2-ene-1-ol and 3-methyl-2-nitrooxybut-3-ene-1-ol. Oxidation of these molecules by OH and ozone was studied using both chemical ionization mass spectrometry and thermo-dissociation laser induced fluorescence. The OH reaction rate constants at 300 K measured relative to propene at 745 Torr are (1.1 ± 0.2) × 10(-10) cm(3) molecule(-1) s(-1) for both the E and Z isomers and (4.2 ± 0.7) × 10(-11) cm(3) molecule(-1) s(-1) for the third isomer. The ozone reaction rate constants for (E/Z)-2-methyl-4-nitrooxybut-2-ene-1-ol are (2.7 ± 0.5) × 10(-17) and (2.9 ± 0.5) × 10(-17) cm(3) molecule(-1) s(-1), respectively. 3-Methyl-2-nitrooxybut-3-ene-1-ol reacts with ozone very slowly, within the range of (2.5-5) × 10(-19) cm(3) molecule(-1) s(-1). Reaction pathways, product yields, and implications for atmospheric chemistry are discussed. A condensed mechanism suitable for use in atmospheric chemistry models is presented.
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Affiliation(s)
- Lance Lee
- Department of Chemistry, University of California , Berkeley, California 94709, United States
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10
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Orlando JJ, Tyndall GS. Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance. Chem Soc Rev 2012; 41:6294-317. [PMID: 22847633 DOI: 10.1039/c2cs35166h] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- John J Orlando
- National Center for Atmospheric Research, Earth System Laboratory, Atmospheric Chemistry Division, Boulder, USA.
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11
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Elrod MJ. Kinetics Study of the Aromatic Bicyclic Peroxy Radical + NO Reaction: Overall Rate Constant and Nitrate Product Yield Measurements. J Phys Chem A 2011; 115:8125-30. [DOI: 10.1021/jp204308f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew J. Elrod
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
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12
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Birdsall AW, Elrod MJ. Comprehensive NO-Dependent Study of the Products of the Oxidation of Atmospherically Relevant Aromatic Compounds. J Phys Chem A 2011; 115:5397-407. [DOI: 10.1021/jp2010327] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adam W. Birdsall
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
| | - Matthew J. Elrod
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
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13
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Krasnoperov LN, Butkovskaya N, Le Bras G. Branching Ratios in the Hydroxyl Reaction with Propene. J Phys Chem A 2011; 115:2498-508. [DOI: 10.1021/jp107178n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lev N. Krasnoperov
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Nadezhda Butkovskaya
- Institut de Combustion, Aerothermique, Reactivite et Environnement (ICARE), CNRS-INSIS, 45071 Orleans, France
| | - Georges Le Bras
- Institut de Combustion, Aerothermique, Reactivite et Environnement (ICARE), CNRS-INSIS, 45071 Orleans, France
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14
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Birdsall AW, Andreoni JF, Elrod MJ. Investigation of the role of bicyclic peroxy radicals in the oxidation mechanism of toluene. J Phys Chem A 2011; 114:10655-63. [PMID: 20836528 DOI: 10.1021/jp105467e] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The products of the primary OH-initiated oxidation of toluene were investigated using the turbulent flow chemical ionization mass spectrometry technique under different oxygen, NO, and initial OH radical concentrations as well as a range of total pressures. The bicyclic peroxy radical intermediate, a key proposed intermediate species in the Master Chemical Mechanism (MCM) for the atmospheric oxidation of toluene, was detected for the first time. The toluene oxidation mechanism was shown to have a strong oxygen concentration dependence, presumably due to the central role of the bicyclic peroxy radical in determining the stable product distribution at atmospheric oxygen concentrations. The results also suggest a potential role for bicyclic peroxy radical + HO(2) reactions at high HO(2)/NO ratios. These reactions are postulated to be a source of the inconsistencies between environmental chamber results and predictions from the MCM.
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Affiliation(s)
- Adam W Birdsall
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, USA
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15
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Ghosh B, Bugarin A, Connell BT, North SW. Isomer-selective study of the OH-initiated oxidation of isoprene in the presence of O(2) and NO: 2. the major OH addition channel. J Phys Chem A 2010; 114:2553-60. [PMID: 20121059 DOI: 10.1021/jp909052t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the first isomeric-selective study of the dominant isomeric pathway in the OH-initiated oxidation of isoprene in the presence of O2 and NO using the laser photolysis-laser induced fluorescence (LP-LIF) technique. The photolysis of monodeuterated/nondeuterated 2-iodo-2-methylbut-3-en-1-ol results exclusively in the dominant OH-isoprene addition product, providing important insight into the oxidation mechanism. On the basis of kinetic analysis of OH cycling experiments, we have determined the rate constant for O2 addition to the hydroxyalkyl radical to be 1.0(-0.5)+1.7 x 10(-12) cm3 s(-1), and we find a value of 8.1-2.3+3.4 x 10(-12) cm3 s(-1) for the overall reaction rate constant of the resulting hydroxyperoxy radical with NO. We also report the first clear experimental evidence of the (E) form of the delta-hydroxyalkoxy channel through isotopic labeling experiments and quantify its branching ratio to be (10 +/- 3)%. This puts a rigorous upper limit on the branching of the (E)-delta-hydroxyalkoxy radical channel. Since our measured isomeric-selective rate constants for the dominant outer channel in OH-initiated isoprene chemistry are similar to the overall rate constants derived from nonisomeric kinetics, we predict that the remaining outer addition channel will have similar reactivity.
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Affiliation(s)
- Buddhadeb Ghosh
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842, USA
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da Silva G, Graham C, Wang ZF. Unimolecular beta-hydroxyperoxy radical decomposition with OH recycling in the photochemical oxidation of isoprene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:250-256. [PMID: 19943615 DOI: 10.1021/es900924d] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel process in the photochemical oxidation of isoprene that recycles hydroxyl (OH) radicals has been identified using first-principles computational chemistry. Isoprene is the dominant biogenic volatile organic compound (VOC), and its oxidation controls chemistry in the forest boundary layer and is also thought to contribute to cloud formation in marine environments. The mechanism described here involves rapid unimolecular decomposition of the two major peroxy radicals (beta-hydroxyperoxy radicals) produced by OH-initiated isoprene oxidation. Peroxy radicals are well-known as key intermediates in VOC oxidation, but up to now were only thought to be destroyed in bimolecular reactions. The process described here leads to OH recycling with up to around 60% efficiency in environments with low levels of peroxy radicals and NO(x). In forested environments reaction of the beta-hydroxyperoxy radicals with HO2 is expected to dominate, with a small contribution from the mechanism described here. Peroxy radical decomposition will be more important in the unpolluted marine boundary layer, where lower levels of NO and HO2 are encountered.
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Affiliation(s)
- Gabriel da Silva
- Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville 3010, Victoria, Australia.
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17
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Baltaretu CO, Lichtman EI, Hadler AB, Elrod MJ. Primary atmospheric oxidation mechanism for toluene. J Phys Chem A 2009; 113:221-30. [PMID: 19118482 DOI: 10.1021/jp806841t] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The products of the primary OH-initiated oxidation of toluene were investigated using the turbulent flow chemical ionization mass spectrometry technique at temperatures ranging from 228 to 298 K. A major dienedial-producing pathway was detected for the first time for toluene oxidation, and glyoxal and methylglyoxal were found to be minor primary oxidation products. The results suggest that secondary oxidation processes involving dienedial and epoxide primary products are likely responsible for previous observations of glyoxal and methylglyoxal products from toluene oxidation. Because the dienedial-producing pathway is a null cycle for tropospheric ozone production and glyoxal and methylglyoxal are important secondary organic aerosol precursors, these new findings have important implications for the modeling of toluene oxidation in the atmosphere.
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Affiliation(s)
- Cristian O Baltaretu
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, USA
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18
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Lesar A, Salta Z, Kovačič S, Kosmas AM. Theoretical characterization of halogenated methylperoxy nitrites CX Y3−OONO (X, Y = H, F, Cl). Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hsin HY, Elrod MJ. Overall Rate Constant Measurements of the Reaction of Hydroxy- and Chloroalkylperoxy Radicals Derived from Methacrolein and Methyl Vinyl Ketone with Nitric Oxide. J Phys Chem A 2007; 111:613-9. [PMID: 17249751 DOI: 10.1021/jp0665574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The overall rate constants of the reactions of NO with hydroxy- and chloroalkylperoxy radicals, derived from the OH- and Cl-initiated oxidation of methacrolein and methyl vinyl ketone, respectively, were directly determined for the first time using the turbulent-flow technique and pseudo-first-order kinetics conditions with high-pressure chemical ionization mass spectrometry for the direct detection of peroxy radical reactants. The individual 100 Torr, 298 K hydroxyalkylperoxy + NO rate constants for the methacrolein [(0.93 +/- 0.12) (2sigma) x 10(-11) cm3 molecule(-1) s(-1)] and methyl vinyl ketone [(0.84 +/- 0.10) x 10(-11) cm3 molecule(-1) s(-1)] systems were found to be identical within the 95% confidence interval associated with each separate measurement, as were the chloroalkylperoxy + NO rate constants for both methacrolein [(1.17 +/- 0.11) x 10(-11) cm3 molecule(-1) s(-1)] and methyl vinyl ketone [(1.14 +/- 0.14) x 10(-11) cm3 molecule(-1) s(-1)]. However, the difference in the rate constants between the hydroxyperoxy + NO and chloroalkylperoxy + NO systems was found to be statistically significant, with the chloroalkylperoxy + NO rate constants about 30% higher than the corresponding hydroxyalkylperoxy + NO rate constants. This substituent effect was rationalized via a frontier molecular orbital model approach.
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Affiliation(s)
- Hong Yuan Hsin
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, USA
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20
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Patchen AK, Pennino MJ, Kiep AC, Elrod MJ. Direct kinetics study of the product-forming channels of the reaction of isoprene-derived hydroxyperoxy radicals with NO. INT J CHEM KINET 2007. [DOI: 10.1002/kin.20248] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Percival CJ, Shallcross DE, Canosa-Mas CE, Dyke JM. Recent advances in the application of discharge-flow to the determination of gas-phase rate coefficients at pressures and temperatures of relevance to the Earth's atmosphere. J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2005.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Patchen AK, Pennino MJ, Elrod MJ. Overall Rate Constant Measurements of the Reaction of Chloroalkylperoxy Radicals with Nitric Oxide. J Phys Chem A 2005; 109:5865-71. [PMID: 16833921 DOI: 10.1021/jp050388q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The overall rate constants of the NO reaction with chloroalkylperoxy radicals derived from the Cl-initiated oxidation of several atmospherically abundant alkenes-ethene, propene, 1-butene, 2-butene, 2-methylpropene, 1,3-butadiene, and isoprene (2-methyl-1,3-butadiene)-were determined for the first time via the turbulent flow technique and pseudo-first-order kinetics conditions with high-pressure chemical ionization mass spectrometry for the direct detection of chloroalkylperoxy radical reactants. The individual 100 Torr, 298 K rate constants for each monoalkene system were found to be identical within the 95% confidence interval associated with each separate measurement, whereas the corresponding rate constants for 1,3-butadiene and isoprene were both approximately 20% higher than the monoalkene mean value. Our previous study of the reaction of hydroxylalkylperoxy radicals (derived from the OH-initiated oxidation of alkenes) with NO yielded identical rate constants for all of the alkenes under study, with a rate constant value within the statistical uncertainty of the value determined here for the NO reaction of chloroalkylperoxy radicals derived from monoalkenes. Thus, the reaction of NO with chloroalkylperoxy radicals derived from dialkenes is found to be significantly faster than the NO reaction with either chloroalkylperoxy radicals derived from monoalkenes or hydroxyalkylperoxy radicals derived from either mono- or dialkenes.
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Affiliation(s)
- Amie K Patchen
- Department of Chemistry, Oberlin College, Oberlin, Ohio 44074, USA
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Yeung LY, Pennino MJ, Miller AM, Elrod MJ. Kinetics and Mechanistic Studies of the Atmospheric Oxidation of Alkynes. J Phys Chem A 2005; 109:1879-89. [PMID: 16833520 DOI: 10.1021/jp0454671] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Kinetics studies of the OH-initiated oxidation of 2-butyne, propyne, and acetylene were conducted at 100 Torr and 298 K using turbulent flow chemical ionization mass spectrometry. The major oxidation products were identified, and with the aid of supporting electronic structure thermodynamics calculations, a general OH-initiated oxidation mechanism for the alkynes is proposed. The major product branching ratio and the product-forming rate constants for the 2-butyne-OH adduct + O(2) reaction were experimentally determined as well. The atmospheric implications of the chemical oxidation mechanism and kinetics results are discussed.
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Affiliation(s)
- Laurence Y Yeung
- Department of Chemistry, Oberlin College, Oberlin, Ohio 44074, USA
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