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Yang X, Li Y, Ma X, Tan Z, Lu K, Zhang Y. Unclassical Radical Generation Mechanisms in the Troposphere: A Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:15888-15909. [PMID: 39206567 DOI: 10.1021/acs.est.4c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Hydroxyl (OH) and hydroperoxyl (HO2) radicals, collectively known as HOx radicals, are crucial in removing primary pollutants, controlling atmospheric oxidation capacity, and regulating global air quality and climate. An imbalance between radical observations and simulations has been identified based on radical closure experiments, a valuable tool for accessing the state-of-the-art chemical mechanisms, demonstrating a deviation between the existing and actual tropospheric mechanisms. In the past decades, researchers have attempted to explain this deviation and proposed numerous radical generation mechanisms. However, these newly proposed unclassical radical generation mechanisms have not been systematically reviewed, and previous radical-related reviews dominantly focus on radical measurement instruments and radical observations in extensive field campaigns. Herein, we overview the unclassical generation mechanisms of radicals, mainly focusing on outlining the methodology and results of radical closure experiments worldwide and systematically introducing the mainstream mechanisms of unclassical radical generation, involving the bimolecular reaction of HO2 and organic peroxy radicals (RO2), RO2 isomerization, halogen chemistry, the reaction of H2O with O2 over soot, epoxide formation mechanism, mechanism of electronically excited NO2 and water, and prompt HO2 formation in aromatic oxidation. Finally, we highlight the existing gaps in the current studies and suggest possible directions for future research. This review of unclassical radical generation mechanisms will help promote a comprehensive understanding of the latest radical mechanisms and the development of additional new mechanisms to further explain deviations between the existing and actual mechanisms.
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Affiliation(s)
- Xinping Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
- State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Vehicle Emission Control Center, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yang Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
| | - Xuefei Ma
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
| | - Zhaofeng Tan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
| | - Keding Lu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
| | - Yuanhang Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100084, China
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Alton MW, Johnson VL, Sharma S, Browne EC. Volatile Methyl Siloxane Atmospheric Oxidation Mechanism from a Theoretical Perspective─How is the Siloxanol Formed? J Phys Chem A 2023; 127:10233-10242. [PMID: 38011037 DOI: 10.1021/acs.jpca.3c06287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Despite several investigations on the atmospheric fate of cyclic volatile methyl siloxanes (VMS), the oxidation chemistry of these purely anthropogenic, high production volume compounds is poorly understood. This led to uncertainties in the environmental impact and fate of the oxidation products. According to laboratory measurements, the main VMS oxidation product is the siloxanol (a -CH3 replaced with an -OH); however, none of the mechanisms proposed to date satisfactorily explain its formation. Motivated by our previous experimental observations of VMS oxidation products, we use theoretical quantum chemical calculations to (1) explore a previously unconsidered reaction pathway to form the siloxanol from a reaction of a siloxy radical with gas-phase water, (2) investigate differences in reaction rates of radical intermediates in hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4) oxidation, and (3) attempt to explain the experimentally observed products. Our results suggest that while the proposed reaction of the siloxy radical with water to form the siloxanol can occur, it is too slow to compete with other unimolecular reactions and thus cannot explain the observed siloxanol formation. We also find that the reaction between the initial D3 peroxy radical (RO2•) with HO2• is slower than previously anticipated (calculated as 3 × 10-13 cm3 molecule-1 s-1 for D3 and 2 × 10-11 cm3 molecule-1 s-1 for D4 compared to the general rate of ∼1 × 10-11 cm3 molecule-1 s-1). Finally, we compare the anticipated fates of the RO2• under a variety of conditions and find that a reaction with NO (assuming a general RO2• + NO bimolecular rate constant of 9 × 10-12 cm3 molecule-1 s-1) will likely be the dominant fate in urban conditions, while isomerization can be important in cleaner environments.
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Affiliation(s)
- Mitchell W Alton
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - Virginia L Johnson
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Sandeep Sharma
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Eleanor C Browne
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
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Zuraski K, Grieman FJ, Hui AO, Cowen J, Winiberg FAF, Percival CJ, Okumura M, Sander SP. Acetonyl Peroxy and Hydroperoxy Self- and Cross-Reactions: Temperature-Dependent Kinetic Parameters, Branching Fractions, and Chaperone Effects. J Phys Chem A 2023; 127:7772-7792. [PMID: 37683115 PMCID: PMC10518823 DOI: 10.1021/acs.jpca.3c03660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/01/2023] [Indexed: 09/10/2023]
Abstract
The temperature-dependent kinetic parameters, branching fractions, and chaperone effects of the self- and cross-reactions between acetonyl peroxy (CH3C(O)CH2O2) and hydro peroxy (HO2) have been studied using pulsed laser photolysis coupled with infrared (IR) wavelength-modulation spectroscopy and ultraviolet absorption (UVA) spectroscopy. Two IR lasers simultaneously monitored HO2 and hydroxyl (OH), while UVA measurements monitored CH3C(O)CH2O2. For the CH3C(O)CH2O2 self-reaction (T = 270-330 K), the rate parameters were determined to be A = (1.5-0.3+0.4) × 10-13 and Ea/R = -996 ± 334 K and the branching fraction to the alkoxy channel, k2b/k2, showed an inverse temperature dependence following the expression, k2b/k2 = (2.27 ± 0.62) - [(6.35 ± 2.06) × 10-3] T(K). For the reaction between CH3C(O)CH2O2 and HO2 (T = 270-330 K), the rate parameters were determined to be A = (3.4-1.5+2.5) × 10-13 and Ea/R = -547 ± 415 K for the hydroperoxide product channel and A = (6.23-4.4+15.3) × 10-17 and Ea/R = -3100 ± 870 K for the OH product channel. The branching fraction for the OH channel, k1b /k1, follows the temperature-dependent expression, k1b/k1 = (3.27 ± 0.51) - [(9.6 ± 1.7) × 10-3] T(K). Determination of these parameters required an extensive reaction kinetics model which included a re-evaluation of the temperature dependence of the HO2 self-reaction chaperone enhancement parameters due to the methanol-hydroperoxy complex. The second-law thermodynamic parameters for KP,M for the formation of the complex were found to be ΔrH250K° = -38.6 ± 3.3 kJ mol-1 and ΔrS250K° = -110.5 ± 13.2 J mol-1 K-1, with the third-law analysis yielding ΔrH250K° = -37.5 ± 0.25 kJ mol-1. The HO2 self-reaction rate coefficient was determined to be k4 = (3.34-0.80+1.04) × 10-13 exp [(507 ± 76)/T]cm3 molecule-1 s-1 with the enhancement term k4,M″ = (2.7-1.7+4.7) × 10-36 exp [(4700 ± 255)/T]cm6 molecule-2 s-1, proportional to [CH3OH], over T = 220-280 K. The equivalent chaperone enhancement parameter for the acetone-hydroperoxy complex was also required and determined to be k4,A″ = (5.0 × 10-38 - 1.4 × 10-41) exp[(7396 ± 1172)/T] cm6 molecule-2 s-1, proportional to [CH3C(O)CH3], over T = 270-296 K. From these parameters, the rate coefficients for the reactions between HO2 and the respective complexes over the given temperature ranges can be estimated: for HO2·CH3OH, k12 = [(1.72 ± 0.050) × 10-11] exp [(314 ± 7.2)/T] cm3 molecule-1 s-1 and for HO2·CH3C(O)CH3, k15 = [(7.9 ± 0.72) × 10-17] exp [(3881 ± 25)/T] cm3 molecule-1 s-1. Lastly, an estimate of the rate coefficient for the HO2·CH3OH self-reaction was also determined to be k13 = (1.3 ± 0.45) × 10-10 cm3 molecule-1 s-1.
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Affiliation(s)
- Kristen Zuraski
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Fred J. Grieman
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
- Seaver
Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Aileen O. Hui
- Arthur
Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Julia Cowen
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
- Seaver
Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Frank A. F. Winiberg
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Carl J. Percival
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Mitchio Okumura
- Arthur
Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Stanley P. Sander
- NASA
Jet Propulsion Laboratory, California Institute
of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
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Troß J, Carter-Fenk K, Cole-Filipiak NC, Schrader P, Word M, McCaslin LM, Head-Gordon M, Ramasesha K. Excited-State Dynamics during Primary C-I Homolysis in Acetyl Iodide Revealed by Ultrafast Core-Level Spectroscopy. J Phys Chem A 2023; 127:4103-4114. [PMID: 37103479 DOI: 10.1021/acs.jpca.3c01414] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
In typical carbonyl-containing molecules, bond dissociation events follow initial excitation to nπC═O* states. However, in acetyl iodide, the iodine atom gives rise to electronic states with mixed nπC═O* and nσC-I* character, leading to complex excited-state dynamics, ultimately resulting in dissociation. Using ultrafast extreme ultraviolet (XUV) transient absorption spectroscopy and quantum chemical calculations, we present an investigation of the primary photodissociation dynamics of acetyl iodide via time-resolved spectroscopy of core-to-valence transitions of the I atom after 266 nm excitation. The probed I 4d-to-valence transitions show features that evolve on sub-100-fs time scales, reporting on excited-state wavepacket evolution during dissociation. These features subsequently evolve to yield spectral signatures corresponding to free iodine atoms in their spin-orbit ground and excited states with a branching ratio of 1.1:1 following dissociation of the C-I bond. Calculations of the valence excitation spectrum via equation-of-motion coupled cluster with single and double substitutions (EOM-CCSD) show that initial excited states are of spin-mixed character. From the initially pumped spin-mixed state, we use a combination of time-dependent density functional theory (TDDFT)-driven nonadiabatic ab initio molecular dynamics and EOM-CCSD calculations of the N4,5 edge to reveal a sharp inflection point in the transient XUV signal that corresponds to rapid C-I homolysis. By examining the molecular orbitals involved in the core-level excitations at and around this inflection point, we are able to piece together a detailed picture of C-I bond photolysis in which d → σ* transitions give way to d → p excitations as the bond dissociates. We also report theoretical predictions of short-lived, weak 4d → 5d transitions in acetyl iodide, validated by weak bleaching in the experimental transient XUV spectra. This joint experimental-theoretical effort has thus unraveled the detailed electronic structure and dynamics of a strongly spin-orbit coupled system.
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Affiliation(s)
- Jan Troß
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Kevin Carter-Fenk
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Neil C Cole-Filipiak
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Paul Schrader
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Mi'Kayla Word
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Laura M McCaslin
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Krupa Ramasesha
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
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Illmann N, Patroescu-Klotz I, Wiesen P. Organic acid formation in the gas-phase ozonolysis of α,β-unsaturated ketones. Phys Chem Chem Phys 2022; 25:106-116. [PMID: 36476818 DOI: 10.1039/d2cp03210d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Organic acids are key species in determining the radiative properties of the atmosphere due to their contribution to particle formation. Reported discrepancies between field measurements and modelling suggest significant missing sources. Herein, we present a mechanistic investigation on the gas-phase ozonolysis of ethyl vinyl ketone (EVK, 1-penten-3-one), which we chose as a model compound for α,β-unsaturated ketones. Experiments were performed in a 1080 L quartz-glass reaction chamber (QUAREC) at 990 ± 15 mbar and 298 ± 2 K (r. h. ≪ 0.1%) and analysed via long-path FTIR spectrometry and PTR-ToF-MS. The experiments were performed in the presence of an excess of CO to suppress the chemistry of OH radicals. For a comprehensive picture, in selected experiments, SO2 was also added to the reaction system to scavenge the stabilized Criegee intermediates (sCIs) and to investigate their formation yield. Combining the results of both set-ups allowed us to quantify 2-oxobutanal, for which we report vapour-phase FTIR spectra. In addition, we introduce the first-ever infrared spectra of perpropionic acid, which was also positively identified in the EVK + O3 system. A detailed analysis of the experimental findings allowed us to link the identified reaction products (acetaldehyde, ethyl hydroperoxide, and perpropionic acid) to known bimolecular reactions of RO2 radicals. Thereby, it is shown that the EVK + O3 reaction yields formic acid, HC(O)OH, and propionic acid, C2H5C(O)OH, and their formation is not covered by mechanisms reported in the literature. Three different pathways accounting for their formation from chemically activated CIs are proposed and possible implications for the ozonolysis of α,β-unsaturated ketones in the atmosphere are discussed.
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Affiliation(s)
- Niklas Illmann
- Institute for Atmospheric and Environmental Research, Bergische Universität Wuppertal, Gaußstraße 20, 42119 Wuppertal, Germany.
| | - Iulia Patroescu-Klotz
- Institute for Atmospheric and Environmental Research, Bergische Universität Wuppertal, Gaußstraße 20, 42119 Wuppertal, Germany.
| | - Peter Wiesen
- Institute for Atmospheric and Environmental Research, Bergische Universität Wuppertal, Gaußstraße 20, 42119 Wuppertal, Germany.
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6
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Wen Z, Yue H, Zhang Y, Lin X, Ma Z, Zhang W, Wang Z, Zhang C, Fittschen C, Tang X. Self-reaction of C2H5O2 and its cross-reaction with HO2 studied with vacuum ultraviolet photoionization mass spectrometry. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Li J, Wang L, Wang L. Computational Study on the Reaction of β-Hydroxyethylperoxy Radical with HO 2 and Effects of Water Vapor. J Phys Chem A 2022; 126:2234-2243. [PMID: 35362984 DOI: 10.1021/acs.jpca.1c09009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of β-hydroxyethylperoxy radical (β-HEP) and HO2 with and without water was studied using quantum chemistry and kinetic calculations. The main products are HOCH2CH2OOH and 3O2 for the reaction with and without water, while all other reaction channels can be neglected. The rate coefficients of the reaction follow negative temperature dependence. The pseudo-second-order rate coefficients are 2-4 orders of magnitude smaller for the reaction with saturated water vapor, indicating the negligible contribution of water in this reaction. This is probably also true for other peroxy radicals (except for HO2), indicating that a large part of previous results on the water enhancement of reaction rate coefficients might have overestimated the influence of water.
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Affiliation(s)
- Junjie Li
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Lingyu Wang
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Liming Wang
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou 510006, China
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Rate Constants and Branching Ratios for the Self-Reaction of Acetyl Peroxy (CH3C(O)O2•) and Its Reaction with CH3O2. ATMOSPHERE 2022. [DOI: 10.3390/atmos13020186] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The self-reaction of acetylperoxy radicals (CH3C(O)O2•) (R1) as well as their reaction with methyl peroxy radicals (CH3O2•) (R2) have been studied using laser photolysis coupled to a selective time resolved detection of three different radicals by cw-CRDS in the near-infrared range: CH3C(O)O2• was detected in the Ã-X˜ electronic transition at 6497.94 cm−1, HO2• was detected in the 2ν1 vibrational overtone at 6638.2 cm−1, and CH3O2• radicals were detected in the Ã-X˜ electronic transition at 7489.16 cm−1. Pulsed photolysis of different precursors at different wavelengths, always in the presence of O2, was used to generate CH3C(O)O2• and CH3O2• radicals: acetaldehyde (CH3CHO/Cl2 mixture or biacetyle (CH3C(O)C(O)CH3) at 351 nm, and acetone (CH3C(O)CH3) or CH3C(O)C(O)CH3 at 248 nm. From photolysis experiments using CH3C(O)C(O)CH3 or CH3C(O)CH3 as precursor, the rate constant for the self-reaction was found with k1 = (1.3 ± 0.3) × 10−11 cm3s−1, in good agreement with current recommendations, while the rate constant for the cross reaction with CH3O2• was found to be k2 = (2.0 ± 0.4) × 10−11 cm3s−1, which is nearly two times faster than current recommendations. The branching ratio of (R2) towards the radical products was found at 0.67, compared with 0.9 for the currently recommended value. Using the reaction of Cl•-atoms with CH3CHO as precursor resulted in radical profiles that were not reproducible by the model: secondary chemistry possibly involving Cl• or Cl2 might occur, but could not be identified.
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Kuwata KT, DeVault MP, Claypool DJ. Improved Computational Modeling of the Kinetics of the Acetylperoxy + HO 2 Reaction. Faraday Discuss 2022; 238:589-618. [DOI: 10.1039/d2fd00030j] [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
The acetylperoxy + HO2 reaction has multiple impacts on the troposphere, with a triplet pathway leading to peracetic acid + O2 (reaction 1a) competing with singlet pathways leading to acetic...
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10
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Barber VP, Kroll JH. Chemistry of Functionalized Reactive Organic Intermediates in the Earth's Atmosphere: Impact, Challenges, and Progress. J Phys Chem A 2021; 125:10264-10279. [PMID: 34846877 DOI: 10.1021/acs.jpca.1c08221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gas-phase oxidation of organic compounds is an important chemical process in the Earth's atmosphere. It governs oxidant levels and controls the production of key secondary pollutants, and hence has major implications for air quality and climate. Organic oxidation is largely controlled by the chemistry of a few reactive intermediates, namely, alkyl (R) radicals, alkoxy (RO) radicals, peroxy (RO2) radicals, and carbonyl oxides (R1R2COO), which may undergo a number of unimolecular and bimolecular reactions. Our understanding of these intermediates, and the reaction pathways available to them, is based largely on studies of unfunctionalized intermediates, formed in the first steps of hydrocarbon oxidation. However, it has become increasingly clear that intermediates with functional groups, which are generally formed later in the oxidation process, can exhibit fundamentally different reactivity than unfunctionalized ones. In this Perspective, we explore the unique chemistry available to functionalized organic intermediates in the Earth's atmosphere. After a brief review of the canonical chemistry available to unfunctionalized intermediates, we discuss how the addition of functional groups can introduce new reactions, either by changing the energetics or kinetics of a given reaction or by opening up new chemical pathways. We then provide examples of atmospheric reaction classes that are available only to functionalized intermediates. Some of these, such as unimolecular H-shift reactions of RO2 radicals, have been elucidated only relatively recently, and can have important impacts on atmospheric chemistry (e.g., on radical cycling or organic aerosol formation); it seems likely that other, as-yet undiscovered reactions of (multi)functional intermediates may also exist. We discuss the challenges associated with the study of the chemistry of such intermediates and review novel experimental and theoretical approaches that have recently provided (or hold promise for providing) new insights into their atmospheric chemistry. The continued use and development of such techniques and the close collaboration between experimentalists and theoreticians are necessary for a complete, detailed understanding of the chemistry of functionalized intermediates and their impact on major atmospheric chemical processes.
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Affiliation(s)
- Victoria P Barber
- Departments of Civil and Environmental Engineering and Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jesse H Kroll
- Departments of Civil and Environmental Engineering and Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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11
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Absolute Absorption Cross-Section of the Ã←X˜ Electronic Transition of the Ethyl Peroxy Radical and Rate Constant of Its Cross Reaction with HO2. PHOTONICS 2021. [DOI: 10.3390/photonics8080296] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The absolute absorption cross-section of the ethyl peroxy radical C2H5O2 in the Ã←X˜ electronic transition with the peak wavelength at 7596 cm−1 has been determined by the method of dual wavelengths time resolved continuous wave cavity ring down spectroscopy. C2H5O2 radicals were generated from pulsed 351 nm photolysis of C2H6/Cl2 mixture in presence of 100 Torr O2 at T = 295 K. C2H5O2 radicals were detected on one of the CRDS paths. Two methods have been applied for the determination of the C2H5O2 absorption cross-section: (i) based on Cl-atoms being converted alternatively to either C2H5O2 by adding C2H6 or to hydro peroxy radicals, HO2, by adding CH3OH to the mixture, whereby HO2 was reliably quantified on the second CRDS path in the 2ν1 vibrational overtone at 6638.2 cm−1 (ii) based on the reaction of C2H5O2 with HO2, measured under either excess HO2 or under excess C2H5O2 concentration. Both methods lead to the same peak absorption cross-section for C2H5O2 at 7596 cm−1 of σ = (1.0 ± 0.2) × 10−20 cm2. The rate constant for the cross reaction between of C2H5O2 and HO2 has been measured to be (6.2 ± 1.5) × 10−12 cm3 molecule−1 s−1.
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13
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Sandhiya L, Senthilkumar K. Unimolecular decomposition of acetyl peroxy radical: a potential source of tropospheric ketene. Phys Chem Chem Phys 2020; 22:26819-26827. [PMID: 33231595 DOI: 10.1039/d0cp04590j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unimolecular decomposition of acetyl peroxy radicals followed by subsequent nitration is known to lead to the formation of peroxy acetyl nitrate (PAN) in the troposphere. Using high level quantum chemical calculations, we show that the acetyl peroxy radical is a precursor in the formation of tropospheric ketene. The results show that the presence of a single or double water molecule(s) as a catalyst does not influence the decomposition reaction directly to form ketene and hydroperoxy radicals. The electronic excitation of the reactive and product complexes occurs in the wavelength range of ∼1400 nm, suggesting that the complexes undergo photoexcitation in the near IR region. The results ascertain that the dissociation of acetyl peroxy radicals into ketene and hydroperoxy radicals occurs more likely through the excitation route and the corresponding excitation wavelength reveals that the reactions are red-light driven. Three different product complexes, ketene·HO2, ketene·H2O·HO2 and ketene·(H2O)2·HO2, are formed from the reaction. The direct dynamics simulations show that the product complexes are more stable and possess a long lifetime. The calculated temperature dependent equilibrium constant of the product complexes reveals that their atmospheric abundances decrease with increasing altitudes.
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Affiliation(s)
- L Sandhiya
- CSIR - National Institute of Science, Technology and Development Studies, New Delhi-110012, India.
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14
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Zuraski K, Hui AO, Grieman FJ, Darby E, Møller KH, Winiberg FAF, Percival CJ, Smarte MD, Okumura M, Kjaergaard HG, Sander SP. Acetonyl Peroxy and Hydro Peroxy Self- and Cross-Reactions: Kinetics, Mechanism, and Chaperone Enhancement from the Perspective of the Hydroxyl Radical Product. J Phys Chem A 2020; 124:8128-8143. [PMID: 32852951 DOI: 10.1021/acs.jpca.0c06220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pulsed laser photolysis coupled with infrared (IR) wavelength modulation spectroscopy and ultraviolet (UV) absorption spectroscopy was used to study the kinetics and branching fractions for the acetonyl peroxy (CH3C(O)CH2O2) self-reaction and its reaction with hydro peroxy (HO2) at a temperature of 298 K and pressure of 100 Torr. Near-IR and mid-IR lasers simultaneously monitored HO2 and hydroxyl, OH, respectively, while UV absorption measurements monitored the CH3C(O)CH2O2 concentrations. The overall rate constant for the reaction between CH3C(O)CH2O2 and HO2 was found to be (5.5 ± 0.5) × 10-12 cm3 molecule-1 s-1, and the branching fraction for OH yield from this reaction was directly measured as 0.30 ± 0.04. The CH3C(O)CH2O2 self-reaction rate constant was measured to be (4.8 ± 0.8) × 10-12 cm3 molecule-1 s-1, and the branching fraction for alkoxy formation was inferred from secondary chemistry as 0.33 ± 0.13. An increase in the rate of the HO2 self-reaction was also observed as a function of acetone (CH3C(O)CH3) concentration which is interpreted as a chaperone effect, resulting from hydrogen-bond complexation between HO2 and CH3C(O)CH3. The chaperone enhancement coefficient for CH3C(O)CH3 was determined to be kA″ = (4.0 ± 0.2) × 10-29 cm6 molecule-2 s-1, and the equilibrium constant for HO2·CH3C(O)CH3 complex formation was found to be Kc(R14) = (2.0 ± 0.89) × 10-18 cm3 molecule-1; from these values, the rate constant for the HO2 + HO2·CH3C(O)CH3 reaction was estimated to be (2 ± 1) × 10-11 cm3 molecule-1 s-1. Results from UV absorption cross-section measurements of CH3C(O)CH2O2 and prompt OH radical yields arising from possible oxidation of the CH3C(O)CH3-derived alkyl radical are also discussed. Using theoretical methods, no likely pathways for the observed prompt OH radical formation have been found and the prompt OH radical yields thus remain unexplained.
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Affiliation(s)
- Kristen Zuraski
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Aileen O Hui
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Fred J Grieman
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Emily Darby
- Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Kristian H Møller
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø DK-2100, Denmark
| | - Frank A F Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Carl J Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Matthew D Smarte
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Mitchio Okumura
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø DK-2100, Denmark
| | - Stanley P Sander
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
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15
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Kuzhanthaivelan S, Rajakumar B. Kinetic investigation of the reaction of ethylperoxy radicals with ethanol. INT J CHEM KINET 2020. [DOI: 10.1002/kin.21441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- S. Kuzhanthaivelan
- Department of Chemistry Indian Institute of Technology Madras Chennai India
| | - B. Rajakumar
- Department of Chemistry Indian Institute of Technology Madras Chennai India
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16
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Feng B, Sun C, Zhao W, Zhang S. A theoretical investigation on the atmospheric degradation of the radical: reactions with NO, NO 2, and NO 3. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:1554-1565. [PMID: 32608429 DOI: 10.1039/d0em00112k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The radical is the key intermediate in the atmospheric oxidation of benzaldehyde, and its further chemistry contributes to local air pollution. The reaction mechanisms of the radical with NO, NO2, and NO3 were studied by quantum chemistry calculations at the CCSD(T)/CBS//M06-2X/def2-TZVP level of theory. The explicit potential energy curves were provided in order to reveal the atmospheric fate of the radical comprehensively. The main products of the reaction of with NO are predicted to be , CO2 and NO2. The reaction of with NO2 is reversible, and its main product would be C6H5C(O)O2NO2 which was predicted to be more stable than PAN (peroxyacetyl nitrate) at room temperature. The decomposition of C6H5C(O)O2NO2 at different ambient temperatures would be a potential long-range transport source of NOx in the atmosphere. The predominant products of the reaction are predicted to be C6H5C(O)O2H, C6H5C(O)OH, O2 and O3, while HO˙ is of minor importance. So, the reaction of with would be an important source of ozone and carboxylic acids in the local atmosphere, and has less contribution to the regeneration of HO˙ radicals. The reaction of with NO3 should mainly produce , CO2, O2 and NO2, which might play an important role in atmospheric chemistry of peroxy radicals at night, but has less contribution to the night-time conversion of ( and RO˙) to ( and HO˙) in the local atmosphere. The results above are in good accordance with the reported experimental observations.
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Affiliation(s)
- Bo Feng
- School of Chemistry and Chemical Engineering, Key Laboratory of Cluster Science of Ministry of Education, Beijing Institute of Technology, South Zhongguancun Street # 5, Haidian District, Beijing, 100081, P. R. China.
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17
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Weidman JD, Turney JM, Schaefer HF. Energetics and mechanisms for the acetonyl radical + O 2 reaction: An important system for atmospheric and combustion chemistry. J Chem Phys 2020; 152:114301. [PMID: 32199416 DOI: 10.1063/1.5141859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The acetonyl radical (•CH2COCH3) is relevant to atmospheric and combustion chemistry due to its prevalence in many important reaction mechanisms. One such reaction mechanism is the decomposition of Criegee intermediates in the atmosphere that can produce acetonyl radical and OH. In order to understand the fate of the acetonyl radical in these environments and to create more accurate kinetics models, we have examined the reaction system of the acetonyl radical with O2 using highly reliable theoretical methods. Structures were optimized using coupled cluster theory with singles, doubles, and perturbative triples [CCSD(T)] with an atomic natural orbital (ANO0) basis set. Energetics were computed to chemical accuracy using the focal point approach involving perturbative treatment of quadruple excitations [CCSDT(Q)] and basis sets as large as cc-pV5Z. The addition of O2 to the acetonyl radical produces the acetonylperoxy radical, and multireference computations on this reaction suggest it to be barrierless. No submerged pathways were found for the unimolecular isomerization of the acetonylperoxy radical. Besides dissociation to reactants, the lowest energy pathway available for the acetonylperoxy radical is a 1-5 H shift from the methyl group to the peroxy group through a transition state that is 3.3 kcal mol-1 higher in energy than acetonyl radical + O2. The ultimate products from this pathway are the enol tautomer of the acetonyl radical along with O2. Multiple pathways that lead to OH formation are considered; however, all of these pathways are predicted to be energetically inaccessible, except at high temperatures.
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Affiliation(s)
- Jared D Weidman
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
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18
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Orlando JJ, Tyndall GS. The atmospheric oxidation of hydroxyacetone: Chemistry of activated and stabilized CH
3
C(O)CH(OH)OO• radicals between 252 and 298 K. INT J CHEM KINET 2020. [DOI: 10.1002/kin.21346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John J. Orlando
- Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder Colorado
| | - Geoffrey S. Tyndall
- Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder Colorado
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19
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Yang Z, Lin X, Zhou J, Hu M, Gai Y, Zhao W, Long B, Zhang W. Computational study on the mechanism and kinetics for the reaction between HO 2 and n-propyl peroxy radical. RSC Adv 2019; 9:40437-40444. [PMID: 35542643 PMCID: PMC9076281 DOI: 10.1039/c9ra07503h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/28/2019] [Indexed: 11/25/2022] Open
Abstract
The n-propyl peroxy radical (n-C3H7O2) is the key intermediate during atmospheric oxidation of propane (C3H8) which plays an important role in the carbon and nitrogen cycles in the troposphere. In this paper, a comprehensive theoretical study on the reaction mechanism and kinetics of the reaction between HO2 and n-C3H7O2 was performed at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311G(d,p) level of theory. Computational results show that the HO2 + n-C3H7O2 reaction proceeds on both singlet and triplet potential energy surfaces (PESs). From an energetic point of view, the formation of C3H7O2H and 3O2via triplet hydrogen abstraction is the most favorable channel while other product channels are negligible. In addition, the calculated rate constants for the title reaction over the temperature range of 238–398 K were calculated by the multiconformer transition state theory (MC-TST), and the calculated rate constants show a negative temperature dependence. The contributions of the other four reaction channels to the total rate constant are negligible. The negative temperature dependence for the HO2 + n-C3H7O2 reaction in lower temperature regime.![]()
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Affiliation(s)
- Zhenli Yang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China .,University of Science and Technology of China Hefei 230026 China
| | - Xiaoxiao Lin
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China
| | - Jiacheng Zhou
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China .,University of Science and Technology of China Hefei 230026 China
| | - Mingfeng Hu
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China
| | - Yanbo Gai
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China
| | - Weixiong Zhao
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China
| | - Bo Long
- College of Computer and Information Engineering, Guizhou Minzu University Guiyang 550025 China
| | - Weijun Zhang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Hefei 230031 Anhui China .,School of Environmental Science and Optoelectronic Technology, University of Science and Technology of China Hefei 230026 Anhui China
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20
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Salta Z, Liaska S, Papayannis DK, Lesar A, Kosmas AM. Computational studies on the reactions of the peroxy radical CF3OCH2O2 with HO2 and NO. COMPUT THEOR CHEM 2019. [DOI: 10.1016/j.comptc.2019.112510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Hui AO, Okumura M, Sander SP. Temperature Dependence of the Reaction of Chlorine Atoms with CH 3OH and CH 3CHO. J Phys Chem A 2019; 123:4964-4972. [PMID: 31088062 DOI: 10.1021/acs.jpca.9b00038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rate constants of the reactions Cl + CH3OH → CH2OH + HCl ( k1) and Cl + CH3CHO → CH3C(O) + HCl ( k3) were measured at 100 Torr over the temperature range 230.3-297.1 K. Radical chemistry was initiated by pulsed laser photolysis of Cl2 in mixtures of CH3OH and CH3CHO in a flow reactor. Heterodyne near-IR wavelength modulation spectroscopy was used to directly detect HO2 produced from the subsequent reaction of CH2OH with O2 in real time to determine the rate of reaction of Cl with CH3OH. The rate of Cl + CH3CHO was measured relative to that of the Cl + CH3OH reaction. Secondary chemistry, including that of the adducts HO2·CH3OH and HO2·CH3CHO, was taken into account. The Arrhenius expressions were found to be k1( T) = 5.02-1.5+1.8 × 10-11 exp[(20 ± 88)/ T] cm3 molecule-1 s-1 and k3( T) = 6.38-2.0+2.4 × 10-11 exp[(56 ± 90)/ T] cm3 molecule-1 s-1 (2σ uncertainties). The average values of the rate constants over this temperature range were k1 = (5.45 ± 0.37) × 10-11 cm3 molecule-1 s-1 and k3 = (8.00 ± 1.27) × 10-11 cm3 molecule-1 s-1 (2σ uncertainties), consistent with current literature values.
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Affiliation(s)
- Aileen O Hui
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Physics , California Institute of Technology , M/S 127-72, 1200 East California Boulevard , Pasadena , California 91125 , United States
| | - Mitchio Okumura
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Physics , California Institute of Technology , M/S 127-72, 1200 East California Boulevard , Pasadena , California 91125 , United States
| | - Stanley P Sander
- Jet Propulsion Laboratory , California Institute of Technology , 4800 Oak Grove Drive , Pasadena , California 91109 , United States
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22
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Hui AO, Fradet M, Okumura M, Sander SP. Temperature Dependence Study of the Kinetics and Product Yields of the HO 2 + CH 3C(O)O 2 Reaction by Direct Detection of OH and HO 2 Radicals Using 2f-IR Wavelength Modulation Spectroscopy. J Phys Chem A 2019; 123:3655-3671. [PMID: 30942073 DOI: 10.1021/acs.jpca.9b00442] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The HO2 + CH3C(O)O2 reaction consists of three product channels: CH3C(O)OOH + O2 (R1a), CH3C(O)OH + O3 (R1b), and OH + CH3C(O)O + O2 (R1c). The overall rate constant ( k1) and product yields (α1a, α1b, and α1c) were determined over the atmospherically relevant temperature range of 230-294 K at 100 Torr in N2. Time-resolved kinetics measurements were performed in a pulsed laser photolysis experiment in a slow flow cell by employing simultaneous infrared (IR) and ultraviolet (UV) absorption spectroscopy. HO2 and CH3C(O)O2 were formed by Cl-atom reactions with CH3OH and CH3CHO, respectively. Heterodyne near- and mid-infrared (NIR and MIR) wavelength modulation spectroscopy (WMS) was employed to selectively detect HO2 and OH radicals. Ultraviolet absorption at 225 and 250 nm was used to detect various peroxy radicals as well as ozone (O3). These experimental techniques enabled direct measurements of α1c and α1b via time-resolved spectroscopic detection in the MIR and the UV, respectively. At each temperature, experiments were performed at various ratios of initial HO2 and CH3C(O)O2 concentrations to quantify the secondary chemistry. The Arrhenius expression was found to be k1( T) = 1.38-0.63+1.17 × 10-12 exp[(730 ± 170)/ T] cm3 molecule-1 s-1. α1a was temperature-independent while α1b and α1c decreased and increased, respectively, with increasing temperatures. These trends are consistent with the current recommendation by the IUPAC data evaluation. Hydrogen-bonded adducts of HO2 with the precursors, HO2·CH3OH and HO2·CH3CHO, played a role at lower temperatures; as part of this work, rate enhancements of the HO2 self-reaction due to reactions of the adducts with HO2 were also measured.
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Affiliation(s)
- Aileen O Hui
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Physics , California Institute of Technology , M/S 127-72, 1200 East California Boulevard , Pasadena , California 91125 , United States
| | - Mathieu Fradet
- Jet Propulsion Laboratory , California Institute of Technology , 4800 Oak Grove Drive , Pasadena , California 91109 , United States
| | - Mitchio Okumura
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Physics , California Institute of Technology , M/S 127-72, 1200 East California Boulevard , Pasadena , California 91125 , United States
| | - Stanley P Sander
- Jet Propulsion Laboratory , California Institute of Technology , 4800 Oak Grove Drive , Pasadena , California 91109 , United States
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23
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Gnanaprakasam M, Sandhiya L, Senthilkumar K. Mechanism and kinetics of the oxidation of dimethyl carbonate by hydroxyl radical in the atmosphere. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:3357-3367. [PMID: 30511221 DOI: 10.1007/s11356-018-3831-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
The mechanism and kinetics for the reaction of dimethyl carbonate (DMC) with OH radical have been studied by using quantum chemical methods. Four reaction pathways were identified for the initial reaction. In the first two pathways, hydrogen atom abstraction is taking place and alkyl radical intermediate is formed with the energy barrier of 6.4 and 7.9 kcal/mol. In the third pathway, OH addition reaction to the carbonyl carbon (C2) atom of DMC and intermediate, I2, is formed with an energy barrier of 11.9 kcal/mol. In the fourth pathway, along with CH3O●, methyl hydrogen carbonate is formed. For this C-O bond breaking and O-H addition reaction, the energy barrier is 27 kcal/mol. The calculated enthalpy and Gibbs energy values show that the studied initial reactions are exothermic and exoergic except the OH addition reaction. For the initial reactions, the rate constants were calculated by using canonical variational transition state theory (CVT) with small curvature tunneling (SCT) correction over the temperature range of 278-1200 K. At 298 K, the calculated rate coefficient for the in-plane and out-of-plane hydrogen atom abstraction reaction pathway is 2.30 × 10-13 and 0.02 × 10-13 cm3 molecule-1 s-1. Further, the reaction between alkyl radical intermediate formed from the first pathway and O2 is studied. The reaction of alkyl peroxy radical intermediate with atmospheric oxidants, HO2, NO, and NO2 is also studied. It was found that the formic (methyl carbonic) anhydride is the end product formed from the atmospheric oxidation and secondary reactions of DMC.
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Affiliation(s)
| | - Lakshmanan Sandhiya
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA
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24
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Iyer S, Reiman H, Møller KH, Rissanen MP, Kjaergaard HG, Kurtén T. Computational Investigation of RO 2 + HO 2 and RO 2 + RO 2 Reactions of Monoterpene Derived First-Generation Peroxy Radicals Leading to Radical Recycling. J Phys Chem A 2018; 122:9542-9552. [PMID: 30449100 DOI: 10.1021/acs.jpca.8b09241] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of biogenically emitted volatile organic compounds (BVOC) plays an important role in the formation of secondary organic aerosols (SOA) in the atmosphere. Peroxy radicals (RO2) are central intermediates in the BVOC oxidation process. Under clean (low-NO x) conditions, the main bimolecular sink reactions for RO2 are with the hydroperoxy radical (HO2) and with other RO2 radicals. Especially for small RO2, the RO2 + HO2 reaction mainly leads to closed-shell hydroperoxide products. However, there exist other known RO2 + HO2 and RO2 + RO2 reaction channels that can recycle radicals and oxidants in the atmosphere, potentially leading to lower-volatility products and enhancing SOA formation. In this work, we present a thermodynamic overview of two such reactions: (a) RO2 + HO2 → RO + OH + O2 and (b) R'O2 + RO2 → R'O + RO + O2 for selected monoterpene + oxidant derived peroxy radicals. The monoterpenes considered are α-pinene, β-pinene, limonene, trans-β-ocimene, and Δ3-carene. The oxidants considered are the hydroxyl radical (OH), the nitrate radical (NO3), and ozone (O3). The reaction Gibbs energies were calculated at the DLPNO-CCSD(T)/def2-QZVPP//ωB97X-D/aug-cc-pVTZ level of theory. All reactions studied here were found to be exergonic in terms of Gibbs energy. On the basis of a comparison with previous mechanistic studies, we predict that reaction a and reaction b are likely to be most important for first-generation peroxy radicals from O3 oxidation (especially for β-pinene), while being less so for most first-generation peroxy radicals from OH and NO3 oxidation. This is because both reactions are comparatively more exergonic for the O3 oxidized systems than their OH and NO3 oxidized counterparts. Our results indicate that bimolecular reactions of certain complex RO2 may contribute to an increase in radical and oxidant recycling under high HO2 conditions in the atmosphere, which can potentially enhance SOA formation.
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Affiliation(s)
- Siddharth Iyer
- Department of Chemistry and Institute for Atmospheric and Earth System Research (INAR) , University of Helsinki , P.O. Box 55, FI-00014 , Helsinki , Finland
| | - Heidi Reiman
- Department of Chemistry , University of Helsinki , P.O. Box 55, FI-00014 , Helsinki , Finland
| | - Kristian H Møller
- Department of Chemistry , University of Copenhagen , DK-2100 Copenhagen Ø , Denmark
| | - Matti P Rissanen
- Department of Physics and Institute for Atmospheric and Earth System Research (INAR) , University of Helsinki , P.O. Box 64, FI-00014 , Helsinki , Finland
| | - Henrik G Kjaergaard
- Department of Chemistry , University of Copenhagen , DK-2100 Copenhagen Ø , Denmark
| | - Theo Kurtén
- Department of Chemistry and Institute for Atmospheric and Earth System Research (INAR) , University of Helsinki , P.O. Box 55, FI-00014 , Helsinki , Finland
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25
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Vereecken L, Aumont B, Barnes I, Bozzelli J, Goldman M, Green W, Madronich S, Mcgillen M, Mellouki A, Orlando J, Picquet-Varrault B, Rickard A, Stockwell W, Wallington T, Carter W. Perspective on Mechanism Development and Structure-Activity Relationships for Gas-Phase Atmospheric Chemistry. INT J CHEM KINET 2018. [DOI: 10.1002/kin.21172] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- L. Vereecken
- Institute for Energy and Climate Research: IEK-8 Troposphere; Forschungszentrum Jülich GmbH; Jülich Germany
| | - B. Aumont
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA); UMR 7583 CNRS; Universités Paris-Est Créteil et Paris Diderot; Institut Pierre-Simon Laplace; Créteil Cedex France
| | - I. Barnes
- School of Mathematics and Natural Sciences; Physical & Theoretical Chemistry; University of Wuppertal; Wuppertal Germany
| | - J.W. Bozzelli
- Department of Chemistry and Environmental Science; New Jersey Institute of Technology; Newark NJ 07102
| | - M.J. Goldman
- Department of Chemical Engineering; Massachusetts Institute of Technology; Cambridge MA 02139
| | - W.H. Green
- Department of Chemical Engineering; Massachusetts Institute of Technology; Cambridge MA 02139
| | - S. Madronich
- Atmospheric Chemistry Observations and Modeling Laboratory; National Center for Atmospheric Research; Boulder CO 80307
| | - M.R. Mcgillen
- School of Chemistry; University of Bristol; Cantock's Close; Bristol BS8 1TS UK
| | - A. Mellouki
- Institut de Combustion; Aérothermique, Réactivité et Environnement (ICARE); CNRS/OSUC; 45071 Orléans Cedex 2 France
| | - J.J. Orlando
- Atmospheric Chemistry Observations and Modeling Laboratory; National Center for Atmospheric Research; Boulder CO 80307
| | - B. Picquet-Varrault
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA); UMR 7583 CNRS; Universités Paris-Est Créteil et Paris Diderot; Institut Pierre-Simon Laplace; Créteil Cedex France
| | - A.R. Rickard
- Wolfson Atmospheric Chemistry Laboratories; Department of Chemistry; University of York; York YO10 5DD UK
- National Centre for Atmospheric Science; University of York; York YO10 5DD UK
| | - W.R. Stockwell
- Department of Physics; University of Texas at El Paso; El Paso TX 79968 USA
| | - T.J. Wallington
- Research & Advanced Engineering; Ford Motor Company; Dearborn MI 48121-2053
| | - W.P.L. Carter
- College of Engineering; Center for Environmental Research and Technology (CE-CERT); University of California; Riverside CA 92521
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26
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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: 145] [Impact Index Per Article: 24.2] [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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27
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Mao J, Carlton A, Cohen RC, Brune WH, Brown SS, Wolfe GM, Jimenez JL, Pye HOT, Ng NL, Xu L, McNeill VF, Tsigaridis K, McDonald BC, Warneke C, Guenther A, Alvarado MJ, de Gouw J, Mickley LJ, Leibensperger EM, Mathur R, Nolte CG, Portmann RW, Unger N, Tosca M, Horowitz LW. Southeast Atmosphere Studies: learning from model-observation syntheses. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018; 18:2615-2651. [PMID: 29963079 PMCID: PMC6020695 DOI: 10.5194/acp-18-2615-2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Concentrations of atmospheric trace species in the United States have changed dramatically over the past several decades in response to pollution control strategies, shifts in domestic energy policy and economics, and economic development (and resulting emission changes) elsewhere in the world. Reliable projections of the future atmosphere require models to not only accurately describe current atmospheric concentrations, but to do so by representing chemical, physical and biological processes with conceptual and quantitative fidelity. Only through incorporation of the processes controlling emissions and chemical mechanisms that represent the key transformations among reactive molecules can models reliably project the impacts of future policy, energy and climate scenarios. Efforts to properly identify and implement the fundamental and controlling mechanisms in atmospheric models benefit from intensive observation periods, during which collocated measurements of diverse, speciated chemicals in both the gas and condensed phases are obtained. The Southeast Atmosphere Studies (SAS, including SENEX, SOAS, NOMADSS and SEAC4RS) conducted during the summer of 2013 provided an unprecedented opportunity for the atmospheric modeling community to come together to evaluate, diagnose and improve the representation of fundamental climate and air quality processes in models of varying temporal and spatial scales. This paper is aimed at discussing progress in evaluating, diagnosing and improving air quality and climate modeling using comparisons to SAS observations as a guide to thinking about improvements to mechanisms and parameterizations in models. The effort focused primarily on model representation of fundamental atmospheric processes that are essential to the formation of ozone, secondary organic aerosol (SOA) and other trace species in the troposphere, with the ultimate goal of understanding the radiative impacts of these species in the southeast and elsewhere. Here we address questions surrounding four key themes: gas-phase chemistry, aerosol chemistry, regional climate and chemistry interactions, and natural and anthropogenic emissions. We expect this review to serve as a guidance for future modeling efforts.
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Affiliation(s)
- Jingqiu Mao
- Geophysical Institute and Department of Chemistry, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Annmarie Carlton
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Ronald C. Cohen
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - William H. Brune
- Department of Meteorology, Pennsylvania State University, University Park, PA, USA
| | - Steven S. Brown
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
| | - Glenn M. Wolfe
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Jose L. Jimenez
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
| | - Havala O. T. Pye
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Nga Lee Ng
- School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lu Xu
- School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - V. Faye McNeill
- Department of Chemical Engineering, Columbia University, New York, NY USA
| | - Kostas Tsigaridis
- Center for Climate Systems Research, Columbia University, New York, NY, USA
- NASA Goddard Institute for Space Studies, New York, NY, USA
| | - Brian C. McDonald
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Carsten Warneke
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Alex Guenther
- Department of Earth System Science, University of California, Irvine, CA, USA
| | | | - Joost de Gouw
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
| | - Loretta J. Mickley
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | | | - Rohit Mathur
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Christopher G. Nolte
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Robert W. Portmann
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
| | - Nadine Unger
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Mika Tosca
- School of the Art Institute of Chicago (SAIC), Chicago, IL 60603, USA
| | - Larry W. Horowitz
- Geophysical Fluid Dynamics Laboratory–National Oceanic and Atmospheric Administration, Princeton, NJ, USA
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28
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Czekner J, Taatjes CA, Osborn DL, Meloni G. Study of low temperature chlorine atom initiated oxidation of methyl and ethyl butyrate using synchrotron photoionization TOF-mass spectrometry. Phys Chem Chem Phys 2018; 20:5785-5794. [DOI: 10.1039/c7cp08221e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The initial oxidation products of methyl butyrate (MB) and ethyl butyrate (EB) are studied using a time- and energy-resolved photoionization mass spectrometer.
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Affiliation(s)
- Joseph Czekner
- University of San Francisco, Department of Chemistry
- San Francisco
- USA
| | - Craig A. Taatjes
- Combustion Research Facility, Sandia National Laboratories
- Livermore
- USA
| | - David L. Osborn
- Combustion Research Facility, Sandia National Laboratories
- Livermore
- USA
| | - Giovanni Meloni
- University of San Francisco, Department of Chemistry
- San Francisco
- USA
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29
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Computational study on mechanisms of C2H5O2+OH reaction and properties of C2H5O3H complex. Chem Res Chin Univ 2017. [DOI: 10.1007/s40242-017-7055-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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Assaf E, Fittschen C. Cross Section of OH Radical Overtone Transition near 7028 cm–1 and Measurement of the Rate Constant of the Reaction of OH with HO2 Radicals. J Phys Chem A 2016; 120:7051-9. [DOI: 10.1021/acs.jpca.6b06477] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Emmanuel Assaf
- CNRS, UMR 8522 - PC2A - Physicochimie
des Processus de Combustion et de l’Atmosphère, Université Lille, F-59000 Lille, France
| | - Christa Fittschen
- CNRS, UMR 8522 - PC2A - Physicochimie
des Processus de Combustion et de l’Atmosphère, Université Lille, F-59000 Lille, France
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31
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Li J, Mao J, Min KE, Washenfelder RA, Brown SS, Kaiser J, Keutsch FN, Volkamer R, Wolfe GM, Hanisco TF, Pollack IB, Ryerson TB, Graus M, Gilman JB, Lerner BM, Warneke C, de Gouw JA, Middlebrook AM, Liao J, Welti A, Henderson BH, McNeill VF, Hall SR, Ullmann K, Donner LJ, Paulot F, Horowitz LW. Observational constraints on glyoxal production from isoprene oxidation and its contribution to organic aerosol over the Southeast United States. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2016; 121:9849-9861. [PMID: 29619286 PMCID: PMC5880315 DOI: 10.1002/2016jd025331] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We use a 0-D photochemical box model and a 3-D global chemistry-climate model, combined with observations from the NOAA Southeast Nexus (SENEX) aircraft campaign, to understand the sources and sinks of glyoxal over the Southeast United States. Box model simulations suggest a large difference in glyoxal production among three isoprene oxidation mechanisms (AM3ST, AM3B, and MCM v3.3.1). These mechanisms are then implemented into a 3-D global chemistry-climate model. Comparison with field observations shows that the average vertical profile of glyoxal is best reproduced by AM3ST with an effective reactive uptake coefficient γglyx of 2 × 10-3, and AM3B without heterogeneous loss of glyoxal. The two mechanisms lead to 0-0.8 μg m-3 secondary organic aerosol (SOA) from glyoxal in the boundary layer of the Southeast U.S. in summer. We consider this to be the lower limit for the contribution of glyoxal to SOA, as other sources of glyoxal other than isoprene are not included in our model. In addition, we find that AM3B shows better agreement on both formaldehyde and the correlation between glyoxal and formaldehyde (RGF = [GLYX]/[HCHO]), resulting from the suppression of δ-isoprene peroxy radicals (δ-ISOPO2). We also find that MCM v3.3.1 may underestimate glyoxal production from isoprene oxidation, in part due to an underestimated yield from the reaction of IEPOX peroxy radicals (IEPOXOO) with HO2. Our work highlights that the gas-phase production of glyoxal represents a large uncertainty in quantifying its contribution to SOA.
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Affiliation(s)
- Jingyi Li
- Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey, USA
| | - Jingqiu Mao
- Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey, USA
- Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, New Jersey, USA
| | - Kyung-Eun Min
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Rebecca A. Washenfelder
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Steven S. Brown
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - Jennifer Kaiser
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Frank N. Keutsch
- School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Rainer Volkamer
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - Glenn M. Wolfe
- Joint Center for Earth System Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
- Atmospheric Chemistry and Dynamics Lab, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Thomas F. Hanisco
- Atmospheric Chemistry and Dynamics Lab, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Ilana B. Pollack
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Thomas B. Ryerson
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
| | - Martin Graus
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Jessica B. Gilman
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Brian M. Lerner
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Carsten Warneke
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Joost A. de Gouw
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Ann M. Middlebrook
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
| | - Jin Liao
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - André Welti
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Barron H. Henderson
- Department of Environmental Engineering Sciences, Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, Florida, USA
| | - V. Faye McNeill
- Department of Chemical Engineering, Columbia University, New York, New York, USA
| | - Samuel R. Hall
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Kirk Ullmann
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Leo J. Donner
- Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, New Jersey, USA
| | - Fabien Paulot
- Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey, USA
- Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, New Jersey, USA
| | - Larry W. Horowitz
- Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, New Jersey, USA
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32
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Nguyen TB, Tyndall GS, Crounse JD, Teng AP, Bates KH, Schwantes RH, Coggon MM, Zhang L, Feiner P, Milller DO, Skog KM, Rivera-Rios JC, Dorris M, Olson KF, Koss A, Wild RJ, Brown SS, Goldstein AH, de Gouw JA, Brune WH, Keutsch FN, Seinfeld JH, Wennberg PO. Atmospheric fates of Criegee intermediates in the ozonolysis of isoprene. Phys Chem Chem Phys 2016; 18:10241-54. [PMID: 27021601 DOI: 10.1039/c6cp00053c] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We use a large laboratory, modeling, and field dataset to investigate the isoprene + O3 reaction, with the goal of better understanding the fates of the C1 and C4 Criegee intermediates in the atmosphere. Although ozonolysis can produce several distinct Criegee intermediates, the C1 stabilized Criegee (CH2OO, 61 ± 9%) is the only one observed to react bimolecularly. We suggest that the C4 Criegees have a low stabilization fraction and propose pathways for their decomposition. Both prompt and non-prompt reactions are important in the production of OH (28% ± 5%) and formaldehyde (81% ± 16%). The yields of unimolecular products (OH, formaldehyde, methacrolein (42 ± 6%) and methyl vinyl ketone (18 ± 6%)) are fairly insensitive to water, i.e., changes in yields in response to water vapor (≤4% absolute) are within the error of the analysis. We propose a comprehensive reaction mechanism that can be incorporated into atmospheric models, which reproduces laboratory data over a wide range of relative humidities. The mechanism proposes that CH2OO + H2O (k(H2O)∼ 1 × 10(-15) cm(3) molec(-1) s(-1)) yields 73% hydroxymethyl hydroperoxide (HMHP), 6% formaldehyde + H2O2, and 21% formic acid + H2O; and CH2OO + (H2O)2 (k(H2O)2∼ 1 × 10(-12) cm(3) molec(-1) s(-1)) yields 40% HMHP, 6% formaldehyde + H2O2, and 54% formic acid + H2O. Competitive rate determinations (kSO2/k(H2O)n=1,2∼ 2.2 (±0.3) × 10(4)) and field observations suggest that water vapor is a sink for greater than 98% of CH2OO in a Southeastern US forest, even during pollution episodes ([SO2] ∼ 10 ppb). The importance of the CH2OO + (H2O)n reaction is demonstrated by high HMHP mixing ratios observed over the forest canopy. We find that CH2OO does not substantially affect the lifetime of SO2 or HCOOH in the Southeast US, e.g., CH2OO + SO2 reaction is a minor contribution (<6%) to sulfate formation. Extrapolating, these results imply that sulfate production by stabilized Criegees is likely unimportant in regions dominated by the reactivity of ozone with isoprene. In contrast, hydroperoxide, organic acid, and formaldehyde formation from isoprene ozonolysis in those areas may be significant.
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Affiliation(s)
- Tran B Nguyen
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.
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33
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Schwantes RH, Teng AP, Nguyen TB, Coggon MM, Crounse JD, St Clair JM, Zhang X, Schilling KA, Seinfeld JH, Wennberg PO. Isoprene NO3 Oxidation Products from the RO2 + HO2 Pathway. J Phys Chem A 2015; 119:10158-71. [PMID: 26335780 DOI: 10.1021/acs.jpca.5b06355] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe the products of the reaction of the hydroperoxy radical (HO(2)) with the alkylperoxy radical formed following addition of the nitrate radical (NO(3)) and O(2) to isoprene. NO(3) adds preferentially to the C(1) position of isoprene (>6 times more favorably than addition to C(4)), followed by the addition of O(2) to produce a suite of nitrooxy alkylperoxy radicals (RO(2)). At an RO(2) lifetime of ∼30 s, δ-nitrooxy and β-nitrooxy alkylperoxy radicals are present in similar amounts. Gas-phase product yields from the RO(2) + HO(2) pathway are identified as 0.75-0.78 isoprene nitrooxy hydroperoxide (INP), 0.22 methyl vinyl ketone (MVK) + formaldehyde (CH(2)O) + hydroxyl radical (OH) + nitrogen dioxide (NO(2)), and 0-0.03 methacrolein (MACR) + CH(2)O + OH + NO(2). We further examined the photochemistry of INP and identified propanone nitrate (PROPNN) and isoprene nitrooxy hydroxyepoxide (INHE) as the main products. INHE undergoes similar heterogeneous chemistry as isoprene dihydroxy epoxide (IEPOX), likely contributing to atmospheric secondary organic aerosol formation.
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Affiliation(s)
- Rebecca H Schwantes
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Alexander P Teng
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Tran B Nguyen
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Matthew M Coggon
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - John D Crounse
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Jason M St Clair
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center , Greenbelt, Maryland 20771, United States.,Joint Center for Earth Systems Technology, University of Maryland Baltimore County , Baltimore, Maryland 21250, United States
| | - Xuan Zhang
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Katherine A Schilling
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - John H Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.,Division of Engineering and Applied Science, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Paul O Wennberg
- Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.,Division of Engineering and Applied Science, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
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34
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Faßheber N, Friedrichs G, Marshall P, Glarborg P. Glyoxal Oxidation Mechanism: Implications for the Reactions HCO + O2 and OCHCHO + HO2. J Phys Chem A 2015; 119:7305-15. [DOI: 10.1021/jp512432q] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Nancy Faßheber
- Institute
of Physical Chemistry, Christian-Albrechts-Universität Kiel, Max-Eyth-Str. 1, 24118 Kiel, Germany
| | - Gernot Friedrichs
- Institute
of Physical Chemistry, Christian-Albrechts-Universität Kiel, Max-Eyth-Str. 1, 24118 Kiel, Germany
| | - Paul Marshall
- Department
of Chemistry and Center for Advanced Scientific Computing and Modeling
(CASCaM), University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203−5017, United States
| | - Peter Glarborg
- Department
of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
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35
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Rissanen MP, Kurtén T, Sipilä M, Thornton JA, Kausiala O, Garmash O, Kjaergaard HG, Petäjä T, Worsnop DR, Ehn M, Kulmala M. Effects of Chemical Complexity on the Autoxidation Mechanisms of Endocyclic Alkene Ozonolysis Products: From Methylcyclohexenes toward Understanding α-Pinene. J Phys Chem A 2015; 119:4633-50. [DOI: 10.1021/jp510966g] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matti P. Rissanen
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Theo Kurtén
- Department of Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland
| | - Mikko Sipilä
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Joel A. Thornton
- Department of Atmospheric
Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Oskari Kausiala
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Olga Garmash
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Henrik G. Kjaergaard
- Department of Chemistry, University of Copenhagen, Universitetsparken
5, 2100 Copenhagen
Ø, Denmark
| | - Tuukka Petäjä
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Douglas R. Worsnop
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
- Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland
- Aerodyne Research Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States
| | - Mikael Ehn
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Markku Kulmala
- Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
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36
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Praske E, Crounse JD, Bates KH, Kurtén T, Kjaergaard HG, Wennberg PO. Atmospheric fate of methyl vinyl ketone: peroxy radical reactions with NO and HO2. J Phys Chem A 2015; 119:4562-72. [PMID: 25486386 DOI: 10.1021/jp5107058] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
First generation product yields from the OH-initiated oxidation of methyl vinyl ketone (3-buten-2-one, MVK) under both low and high NO conditions are reported. In the low NO chemistry, three distinct reaction channels are identified leading to the formation of (1) OH, glycolaldehyde, and acetyl peroxy R2a , (2) a hydroperoxide R2b , and (3) an α-diketone R2c . The α-diketone likely results from HOx-neutral chemistry previously only known to occur in reactions of HO2 with halogenated peroxy radicals. Quantum chemical calculations demonstrate that all channels are kinetically accessible at 298 K. In the high NO chemistry, glycolaldehyde is produced with a yield of 74 ± 6.0%. Two alkyl nitrates are formed with a combined yield of 4.0 ± 0.6%. We revise a three-dimensional chemical transport model to assess what impact these modifications in the MVK mechanism have on simulations of atmospheric oxidative chemistry. The calculated OH mixing ratio over the Amazon increases by 6%, suggesting that the low NO chemistry makes a non-negligible contribution toward sustaining the atmospheric radical pool.
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Affiliation(s)
- Eric Praske
- †Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
| | - John D Crounse
- ‡Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
| | - Kelvin H Bates
- †Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
| | - Theo Kurtén
- § Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki, 00014, Finland
| | - Henrik G Kjaergaard
- ∥Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Paul O Wennberg
- ‡Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States.,⊥Division of Engineering and Applied Science, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
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37
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Rissanen MP, Kurtén T, Sipilä M, Thornton JA, Kangasluoma J, Sarnela N, Junninen H, Jørgensen S, Schallhart S, Kajos MK, Taipale R, Springer M, Mentel TF, Ruuskanen T, Petäjä T, Worsnop DR, Kjaergaard HG, Ehn M. The formation of highly oxidized multifunctional products in the ozonolysis of cyclohexene. J Am Chem Soc 2014; 136:15596-606. [PMID: 25283472 DOI: 10.1021/ja507146s] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The prompt formation of highly oxidized organic compounds in the ozonolysis of cyclohexene (C6H10) was investigated by means of laboratory experiments together with quantum chemical calculations. The experiments were performed in borosilicate glass flow tube reactors coupled to a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer with a nitrate ion (NO3(-))-based ionization scheme. Quantum chemical calculations were performed at the CCSD(T)-F12a/VDZ-F12//ωB97XD/aug-cc-pVTZ level, with kinetic modeling using multiconformer transition state theory, including Eckart tunneling corrections. The complementary investigation methods gave a consistent picture of a formation mechanism advancing by peroxy radical (RO2) isomerization through intramolecular hydrogen shift reactions, followed by sequential O2 addition steps, that is, RO2 autoxidation, on a time scale of seconds. Dimerization of the peroxy radicals by recombination and cross-combination reactions is in competition with the formation of highly oxidized monomer species and is observed to lead to peroxides, potentially diacyl peroxides. The molar yield of these highly oxidized products (having O/C > 1 in monomers and O/C > 0.55 in dimers) from cyclohexene ozonolysis was determined as (4.5 ± 3.8)%. Fully deuterated cyclohexene and cis-6-nonenal ozonolysis, as well as the influence of water addition to the system (either H2O or D2O), were also investigated in order to strengthen the arguments on the proposed mechanism. Deuterated cyclohexene ozonolysis resulted in a less oxidized product distribution with a lower yield of highly oxygenated products and cis-6-nonenal ozonolysis generated the same monomer product distribution, consistent with the proposed mechanism and in agreement with quantum chemical modeling.
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Affiliation(s)
- Matti P Rissanen
- Department of Physics, University of Helsinki , P.O. Box 64, Helsinki, 00014, Finland
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38
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Peeters J, Müller JF, Stavrakou T, Nguyen VS. Hydroxyl Radical Recycling in Isoprene Oxidation Driven by Hydrogen Bonding and Hydrogen Tunneling: The Upgraded LIM1 Mechanism. J Phys Chem A 2014; 118:8625-43. [DOI: 10.1021/jp5033146] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jozef Peeters
- Department
of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
| | - Jean-François Müller
- Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels, Belgium
| | | | - Vinh Son Nguyen
- Department
of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
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39
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Xu L, Kollman MS, Song C, Shilling JE, Ng NL. Effects of NOx on the volatility of secondary organic aerosol from isoprene photooxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:2253-62. [PMID: 24471688 DOI: 10.1021/es404842g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effects of NOx on the volatility of the secondary organic aerosol (SOA) formed from isoprene photooxidation are investigated in environmental chamber experiments. Two types of experiments are performed. In HO2-dominant experiments, organic peroxy radicals (RO2) primarily react with HO2. In mixed experiments, RO2 reacts through multiple pathways, including with NO, NO2, and HO2. The volatility and oxidation state of isoprene SOA are sensitive to and exhibit a nonlinear dependence on NOx levels. Depending on the NOx levels, the SOA formed in mixed experiments can be of similar or lower volatility compared to that formed in HO2-dominant experiments. The dependence of SOA yield, volatility, and oxidation state on the NOx level likely arises from gas-phase RO2 chemistry and succeeding particle-phase oligomerization reactions. The NOx level also plays a strong role in SOA aging. While the volatility of SOA in mixed experiments does not change substantially over time, SOA becomes less volatile and more oxidized as oxidation progresses in HO2-dominant experiments.
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Affiliation(s)
- Lu Xu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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40
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Gross CBM, Dillon TJ, Schuster G, Lelieveld J, Crowley JN. Direct kinetic study of OH and O3 formation in the reaction of CH3C(O)O2 with HO2. J Phys Chem A 2014; 118:974-85. [PMID: 24491030 DOI: 10.1021/jp412380z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction between HO2 and CH3C(O)O2 has three exothermic product channels, forming OH (R3a), peracetic acid (R3b), and acetic acid plus O3 (R3c). The branching ratios of the OH- and ozone-forming reaction channels were determined using a combination of laser-induced fluorescence (LIF, for time-resolved OH concentration measurement) and transient absorption spectroscopy (TAS, for time-resolved O3 concentration measurement) following pulsed laser generation of HO2 and CH3C(O)O2 from suitable precursors. TAS was also used to determine the initial concentration of the reactant peroxy radicals. The data were evaluated by numerical simulation using kinetic models of the measured concentration profiles; a Monte Carlo approach was used to estimate the uncertainties of the rate constants (k3) and branching ratios (α) thus obtained. The reaction channel forming OH (R3a) was found to be the most important with α3a = 0.61 ± 0.09 and α3c = 0.16 ± 0.08. The overall rate coefficient of the title reaction was found to be k3 = (2.1 ± 0.4) × 10(-11) cm(3) molecule(-1) s(-1) for both HO2 and DO2. Use of DO2 resulted in an increase in α3a to 0.80 ± 0.14. Comparison with former studies shows that OH formation via (R3) has been underestimated significantly to date. Possible reasons for these discrepancies and atmospheric implications are discussed.
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Affiliation(s)
- C B M Gross
- Division of Atmospheric Chemistry, Max-Planck-Institut für Chemie , 55128 Mainz, Germany
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41
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Rypkema HA, Francisco JS. Atmospheric Oxidation of Peroxyacetic Acid. J Phys Chem A 2013; 117:14151-62. [DOI: 10.1021/jp409773j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Heather A. Rypkema
- Department of Chemistry and Department of Earth, Atmospheric, and Planetary
Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Joseph S. Francisco
- Department of Chemistry and Department of Earth, Atmospheric, and Planetary
Sciences, Purdue University, West Lafayette, Indiana 47907, United States
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42
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Alam MS, Rickard AR, Camredon M, Wyche KP, Carr T, Hornsby KE, Monks PS, Bloss WJ. Radical Product Yields from the Ozonolysis of Short Chain Alkenes under Atmospheric Boundary Layer Conditions. J Phys Chem A 2013; 117:12468-83. [DOI: 10.1021/jp408745h] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Mohammed S. Alam
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | | | - Marie Camredon
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Kevin P. Wyche
- Department
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K
| | - Timo Carr
- Department
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K
| | - Karen E. Hornsby
- Department
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K
| | - Paul S. Monks
- Department
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K
| | - William J. Bloss
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
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43
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Vu ND, Khamaganov V, Nguyen VS, Carl SA, Peeters J. Absolute Rate Coefficient of the Gas-Phase Reaction between Hydroxyl Radical (OH) and Hydroxyacetone: Investigating the Effects of Temperature and Pressure. J Phys Chem A 2013; 117:12208-15. [DOI: 10.1021/jp407701z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ngoc Duy Vu
- The Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Victor Khamaganov
- The Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Vinh Son Nguyen
- The Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Shaun A. Carl
- The Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Jozef Peeters
- The Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
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44
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Lockhart J, Blitz M, Heard D, Seakins P, Shannon R. Kinetic Study of the OH + Glyoxal Reaction: Experimental Evidence and Quantification of Direct OH Recycling. J Phys Chem A 2013; 117:11027-37. [DOI: 10.1021/jp4076806] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- James Lockhart
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Mark Blitz
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Dwayne Heard
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Paul Seakins
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Robin Shannon
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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45
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Han KM, Park RS, Kim HK, Woo JH, Kim J, Song CH. Uncertainty in biogenic isoprene emissions and its impacts on tropospheric chemistry in East Asia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 463-464:754-771. [PMID: 23867846 DOI: 10.1016/j.scitotenv.2013.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 05/31/2013] [Accepted: 06/02/2013] [Indexed: 06/02/2023]
Abstract
In this study, the accuracy of biogenic isoprene emission fluxes over East Asia during two summer months (July and August) was examined by comparing two tropospheric HCHO columns (ΩHCHO) obtained from the SCIAMACHY sensor and the Community Multi-scale Air Quality (CMAQ v4.7.1) model simulations, using three available biogenic isoprene emission inventories over East Asia: i) GEIA, ii) MEGAN and iii) MOHYCAN. From this comparative analysis, the tropospheric HCHO columns from the CMAQ model simulations, using the MEGAN and MOHYCAN emission inventories (Ω(CMAQ, MEGAN) and Ω(CMAQ, MOHYCAN)), were found to agree well with the tropospheric HCHO columns from the SCIAMACHY observations (Ω(SCIA)). Secondly, the propagation of such uncertainties in the biogenic isoprene emission fluxes to the levels of atmospheric oxidants (e.g., OH and HO2) and other atmospheric gaseous/particulate species over East Asia during the two summer months was also investigated. As the biogenic isoprene emission fluxes decreased from the GEIA to the MEGAN emission inventories, the levels of OH radicals increased by factors of 1.39 and 1.75 over Central East China (CEC) and South China, respectively. Such increases in the OH radical mixing ratios subsequently influence the partitioning of HO(y) species. For example, the HO2/OH ratios from the CMAQ model simulations with GEIA isoprene emissions were 2.7 times larger than those from the CMAQ model simulations based on MEGAN isoprene emissions. The large HO2/OH ratios from the CMAQ model simulations with the GEIA biogenic emission were possibly due to the overestimation of GEIA biogenic isoprene emissions over East Asia. It was also shown that such large changes in HO(x) radicals created large differences on other tropospheric compounds (e.g., NO(y) chemistry) over East Asia during the summer months.
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Affiliation(s)
- K M Han
- School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea; Advanced Environmental Monitoring Research Center (ADEMRC), Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea
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46
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Kjaergaard HG, Knap HC, Ørnsø KB, Jørgensen S, Crounse JD, Paulot F, Wennberg PO. Atmospheric fate of methacrolein. 2. Formation of lactone and implications for organic aerosol production. J Phys Chem A 2012; 116:5763-8. [PMID: 22452294 DOI: 10.1021/jp210853h] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigate the oxidation of methacryloylperoxy nitrate (MPAN) and methacrylicperoxy acid (MPAA) by the hydroxyl radical (OH) theoretically, using both density functional theory [B3LYP] and explicitly correlated coupled cluster theory [CCSD(T)-F12]. These two compounds are produced following the abstraction of a hydrogen atom from methacrolein (MACR) by the OH radical. We use a RRKM master equation analysis to estimate that the oxidation of MPAN leads to formation of hydroxymethyl-methyl-α-lactone (HMML) in high yield. HMML production follows a low potential energy path from both MPAN and MPAA following addition of OH (via elimination of the NO(3) and OH from MPAN and MPAA, respectively). We suggest that the subsequent heterogeneous phase chemistry of HMML may be the route to formation of 2-methylglyceric acid, a common component of organic aerosol produced in the oxidation of methacrolein. Oxidation of acrolein, a photo-oxidation product from 1,3-butadiene, is found to follow a similar route generating hydroxymethyl-α-lactone (HML).
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Affiliation(s)
- Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
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47
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Crounse JD, Knap HC, Ørnsø KB, Jørgensen S, Paulot F, Kjaergaard HG, Wennberg PO. Atmospheric Fate of Methacrolein. 1. Peroxy Radical Isomerization Following Addition of OH and O2. J Phys Chem A 2012; 116:5756-62. [DOI: 10.1021/jp211560u] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- John D. Crounse
- Division of Geological
and Planetary
Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Hasse C. Knap
- Department of Chemistry,
DK-2100 Copenhagen Ø, University of Copenhagen, Copenhagen, Denmark
| | - Kristian B. Ørnsø
- Department of Chemistry,
DK-2100 Copenhagen Ø, University of Copenhagen, Copenhagen, Denmark
| | - Solvejg Jørgensen
- Department of Chemistry,
DK-2100 Copenhagen Ø, University of Copenhagen, Copenhagen, Denmark
| | - Fabien Paulot
- Division
of Engineering and Applied
Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Henrik G. Kjaergaard
- Department of Chemistry,
DK-2100 Copenhagen Ø, University of Copenhagen, Copenhagen, Denmark
| | - Paul O. Wennberg
- Division of Geological
and Planetary
Science, California Institute of Technology, Pasadena, California 91125, United States
- Division
of Engineering and Applied
Science, California Institute of Technology, Pasadena, California 91125, United States
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48
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Zhang P, Wang W, Zhang T, Chen L, Du Y, Li C, Lü J. Theoretical study on the mechanism and kinetics for the self-reaction of C2H5O2 radicals. J Phys Chem A 2012; 116:4610-20. [PMID: 22494036 DOI: 10.1021/jp301308u] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Oxygen-to-oxygen coupling, direct H-abstraction and oxygen-to-(α)carbon nucleophilic substitution processes have been investigated for both the singlet and triplet self-reaction of C(2)H(5)O(2) radicals at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(2d,2p) level to evaluate the reaction mechanisms, possible products and rate constants. The calculated results show that the title reaction mainly occurs through the singlet oxygen-to-oxygen coupling mechanism with the formation of entrance tetroxide intermediates, and the most dominant product is C(2)H(5)O + HO(2) + CH(3)CHO (P5) generated in channel R5. Beginning from the radical products of P5 (C(2)H(5)O, HO(2)) and reactant (C(2)H(5)O(2)), five secondary reactions HO(2) + HO(2) (a), HO(2) + C(2)H(5)O (b), C(2)H(5)O + C(2)H(5)O (c), HO(2) + C(2)H(5)O(2) (d), and C(2)H(5)O + C(2)H(5)O(2) (e) mainly proceed on the triplet potential energy surface. Among these reactions, (a), (b), and (d) are kinetically favorable because of lower barrier heights. The calculated rate constants of channel R5 between 200 and 295 K are almost independent of the temperature, which is in agreement with the experimental report. With regard to the final products distribution, CH(3)CHO, C(2)H(5)OH, C(2)H(5)OOH, H(2)O(2), and (3)O(2) are predicted to be major, whereas C(2)H(5)OOC(2)H(5) should be in minor amount.
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Affiliation(s)
- Pei Zhang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710062, China
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49
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Hasson AS, Tyndall GS, Orlando JJ, Singh S, Hernandez SQ, Campbell S, Ibarra Y. Branching Ratios for the Reaction of Selected Carbonyl-Containing Peroxy Radicals with Hydroperoxy Radicals. J Phys Chem A 2012; 116:6264-81. [PMID: 22483091 DOI: 10.1021/jp211799c] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Alam S. Hasson
- Department of Chemistry, 2555 East San Ramon
Avenue M/S SB70, California State University, Fresno, Fresno, California 93740, United States
| | - Geoffrey S. Tyndall
- Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box
3000, Boulder, Colorado 80307, United States
| | - John J. Orlando
- Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box
3000, Boulder, Colorado 80307, United States
| | - Sukhdeep Singh
- Department of Chemistry, 2555 East San Ramon
Avenue M/S SB70, California State University, Fresno, Fresno, California 93740, United States
| | - Samuel Q. Hernandez
- Department of Chemistry, 2555 East San Ramon
Avenue M/S SB70, California State University, Fresno, Fresno, California 93740, United States
| | - Sean Campbell
- Department of Chemistry, 2555 East San Ramon
Avenue M/S SB70, California State University, Fresno, Fresno, California 93740, United States
| | - Yesenia Ibarra
- Department of Chemistry, 2555 East San Ramon
Avenue M/S SB70, California State University, Fresno, Fresno, California 93740, United States
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50
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Yee LD, Craven JS, Loza CL, Schilling KA, Ng NL, Canagaratna MR, Ziemann PJ, Flagan RC, Seinfeld JH. Secondary organic aerosol formation from low-NO(x) photooxidation of dodecane: evolution of multigeneration gas-phase chemistry and aerosol composition. J Phys Chem A 2012; 116:6211-30. [PMID: 22424261 DOI: 10.1021/jp211531h] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The extended photooxidation of and secondary organic aerosol (SOA) formation from dodecane (C(12)H(26)) under low-NO(x) conditions, such that RO(2) + HO(2) chemistry dominates the fate of the peroxy radicals, is studied in the Caltech Environmental Chamber based on simultaneous gas and particle-phase measurements. A mechanism simulation indicates that greater than 67% of the initial carbon ends up as fourth and higher generation products after 10 h of reaction, and simulated trends for seven species are supported by gas-phase measurements. A characteristic set of hydroperoxide gas-phase products are formed under these low-NO(x) conditions. Production of semivolatile hydroperoxide species within three generations of chemistry is consistent with observed initial aerosol growth. Continued gas-phase oxidation of these semivolatile species produces multifunctional low volatility compounds. This study elucidates the complex evolution of the gas-phase photooxidation chemistry and subsequent SOA formation through a novel approach comparing molecular level information from a chemical ionization mass spectrometer (CIMS) and high m/z ion fragments from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Combination of these techniques reveals that particle-phase chemistry leading to peroxyhemiacetal formation is the likely mechanism by which these species are incorporated in the particle phase. The current findings are relevant toward understanding atmospheric SOA formation and aging from the "unresolved complex mixture," comprising, in part, long-chain alkanes.
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Affiliation(s)
- Lindsay D Yee
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
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