1
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Chen IY, Chang CW, Fittschen C, Luo PL. Accurate Kinetic Studies of OH + HO 2 Radical-Radical Reaction through Direct Measurement of Precursor and Radical Concentrations with High-Resolution Time-Resolved Dual-Comb Spectroscopy. J Phys Chem Lett 2024; 15:3733-3739. [PMID: 38547368 PMCID: PMC11017308 DOI: 10.1021/acs.jpclett.4c00494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
The radical-radical reaction between OH and HO2 has been considered for a long time as an important reaction in tropospheric photochemistry and combustion chemistry. However, a significant discrepancy of an order of magnitude for rate coefficients of this reaction is found between two recent experiments. Herein, we investigate the reaction OH + HO2 via direct spectral quantification of both the precursor (H2O2) and free radicals (OH and HO2) upon the 248 nm photolysis of H2O2 using infrared two-color time-resolved dual-comb spectroscopy. With quantitative and kinetic analysis of concentration profiles of both OH and HO2 at varied conditions, the rate coefficient kOH+HO2 is determined to be (1.10 ± 0.12) × 10-10 cm3 molecule-1 s-1 at 296 K. Moreover, we explore the kinetics of this reaction under conditions in the presence of water, but no enhancement in the kOH+HO2 can be observed. This work as an independent experiment plays a crucial role in revisiting this prototypical radical-radical reaction.
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Affiliation(s)
- I-Yun Chen
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
- Department
of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Che-Wei Chang
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
- Molecular
Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, 11529 Taipei, Taiwan
- International
Graduate Program of Molecular Science and Technology, National Taiwan University, 10617 Taipei, Taiwan
| | - Christa Fittschen
- University
Lille, CNRS, UMR 8522, PC2A−Physicochimie
des Processus de Combustion et de l’Atmosphère, F-59000 Lille, France
| | - Pei-Ling Luo
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
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2
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Fernholz C, Baumann F, Lelieveld J, Crowley JN. Kinetics of the reaction of OH with methyl nitrate (223-343 K). Phys Chem Chem Phys 2024; 26:6646-6654. [PMID: 38329232 DOI: 10.1039/d4cp00054d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Rate coefficients (k4) for the reaction of hydroxyl radicals (OH) with methyl nitrate (CH3ONO2) were measured over the temperature range 232-343 K using pulsed laser photolysis to generate OH and pulsed laser-induced fluorescence to detect it in real-time and under pseudo-first-order conditions. In order to optimize the accuracy of the rate coefficients obtained, the concentration of CH3ONO2 (the reactant in excess) was measured on-line by absorption spectroscopy at 213.86 nm for which the absorption cross-section was also measured (σ213.86 = 1.65 ± 0.09 × 10-18 cm2 molecule-1). The temperature-dependent rate coefficient is described by k4(T) = 7.5 × 10-13 exp[(-1034 ± 40)/T] cm3 molecule-1 s-1 with a room temperature rate coefficient of k4(296 ± 2 K) = (2.32 ± 0.12) × 10-14 cm3 molecule-1 s-1 where the uncertainty includes the statistical error of 2σ and an estimation of the potential systematic bias of 5%. This new dataset helps to consolidate the database for this rate coefficient and to reduce uncertainty in the atmospheric lifetime of CH3ONO2. As part of this study, an approximate rate coefficient for the reaction of H-atoms with CH3ONO2 (k9) was also derived at room temperature: k9(298 K) = (1.68 ± 0.45) × 10-13 cm3 molecule-1 s-1.
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Affiliation(s)
- Christin Fernholz
- Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany.
| | - Fabienne Baumann
- Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany.
| | - Jos Lelieveld
- Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany.
| | - John N Crowley
- Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany.
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3
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Prlj A, Hollas D, Curchod BFE. Deciphering the Influence of Ground-State Distributions on the Calculation of Photolysis Observables. J Phys Chem A 2023; 127:7400-7409. [PMID: 37556330 PMCID: PMC10493954 DOI: 10.1021/acs.jpca.3c02333] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/17/2023] [Indexed: 08/11/2023]
Abstract
Nonadiabatic molecular dynamics offers a powerful tool for studying the photochemistry of molecular systems. Key to any nonadiabatic molecular dynamics simulation is the definition of its initial conditions (ICs), ideally representing the initial molecular quantum state of the system of interest. In this work, we provide a detailed analysis of how ICs may influence the calculation of experimental observables by focusing on the photochemistry of methylhydroperoxide (MHP), the simplest and most abundant organic peroxide in our atmosphere. We investigate the outcome of trajectory surface hopping simulations for distinct sets of ICs sampled from different approximate quantum distributions, namely harmonic Wigner functions and ab initio molecular dynamics using a quantum thermostat (QT). Calculating photoabsorption cross-sections, quantum yields, and translational kinetic energy maps from the results of these simulations reveals the significant effect of the ICs, in particular when low-frequency (∼ a few hundred cm-1) normal modes are connected to the photophysics of the molecule. Overall, our results indicate that sampling ICs from ab initio molecular dynamics using a QT is preferable for flexible molecules with photoactive low-frequency modes. From a photochemical perspective, our nonadiabatic dynamics simulations offer an explanation for a low-energy tail observed at high excitation energy in the translational kinetic energy map of MHP.
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Affiliation(s)
- Antonio Prlj
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
- Division
of Physical Chemistry, Ruđer Bošković
Institute, Zagreb 10000, Croatia
| | - Daniel Hollas
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Basile F. E. Curchod
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
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4
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Prlj A, Marsili E, Hutton L, Hollas D, Shchepanovska D, Glowacki DR, Slavíček P, Curchod BFE. Calculating Photoabsorption Cross-Sections for Atmospheric Volatile Organic Compounds. ACS EARTH & SPACE CHEMISTRY 2022; 6:207-217. [PMID: 35087992 PMCID: PMC8785186 DOI: 10.1021/acsearthspacechem.1c00355] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 12/03/2021] [Indexed: 05/30/2023]
Abstract
Characterizing the photochemical reactivity of transient volatile organic compounds (VOCs) in our atmosphere begins with a proper understanding of their abilities to absorb sunlight. Unfortunately, the photoabsorption cross-sections for a large number of transient VOCs remain unavailable experimentally due to their short lifetime or high reactivity. While structure-activity relationships (SARs) have been successfully employed to estimate the unknown photoabsorption cross-sections of VOCs, computational photochemistry offers another promising strategy to predict not only the vertical electronic transitions of a given molecule but also the width and shape of the bands forming its absorption spectrum. In this work, we focus on the use of the nuclear ensemble approach (NEA) to determine the photoabsorption cross-section of four exemplary VOCs, namely, acrolein, methylhydroperoxide, 2-hydroperoxy-propanal, and (microsolvated) pyruvic acid. More specifically, we analyze the influence that different strategies for sampling the ground-state nuclear density-Wigner sampling and ab initio molecular dynamics with a quantum thermostat-can have on the simulated absorption spectra. We highlight the potential shortcomings of using uncoupled harmonic modes within Wigner sampling of nuclear density to describe flexible or microsolvated VOCs and some limitations of SARs for multichromophoric VOCs. Our results suggest that the NEA could constitute a powerful tool for the atmospheric community to predict the photoabsorption cross-section for transient VOCs.
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Affiliation(s)
- Antonio Prlj
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Emanuele Marsili
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Lewis Hutton
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
| | - Daniel Hollas
- Department
of Chemistry, Durham University, Durham DH1 3LE, U.K.
- Department
of Physical Chemistry, University of Chemistry
and Technology, Prague, Technická 5, Prague 16628, Czech Republic
| | - Darya Shchepanovska
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TH, U.K.
| | - David R. Glowacki
- ArtSci
International Foundation, 5th Floor Mariner House, Bristol BS1 4QD, U.K.
- CiTIUS
Intelligent Technologies Research Centre, Rúa de Jenaro de La Fuente, s/n, Santiago de Compostela 15705, A Coruña, Spain
| | - Petr Slavíček
- Department
of Physical Chemistry, University of Chemistry
and Technology, Prague, Technická 5, Prague 16628, Czech Republic
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5
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Mahata P, Maiti B. Photodissociation Dynamics of Methyl Hydroperoxide at 193 nm: A Trajectory Surface-Hopping Study. J Phys Chem A 2021; 125:10321-10329. [PMID: 34807597 DOI: 10.1021/acs.jpca.1c07785] [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 photodissociation of methyl hydroperoxide (CH3OOH) at 193 nm has been studied using a direct dynamics trajectory surface-hopping (TSH) method. The potential energies, energy gradients, and nonadiabatic couplings are calculated on the fly at the MRCIS(6,7)/aug-cc-pVDZ level of theory. The hopping of a trajectory from one electronic state to another is decided on the basis of Tully's fewest switches algorithm. An analysis of the trajectories reveals that the cleavage of the weakest O-O bond leads to major products CH3O(2E) + OH(2Π), contributing about 72.7% of the overall product formation. This OH elimination was completed in the ground degenerate product state where both the ground singlet (S0) and first excited singlet (S1) states become degenerate. The O-H bond dissociation of CH3OOH is a minor channel contributing about 27.3% to product formation, resulting in products CH3OO + H. An inspection of the trajectories indicates that unlike the major channel OH elimination, the H-atom elimination channel makes a significant contribution (∼3% of the overall product formation) through the nonadiabatic pathway via conical intersection S1/S0 leading to ground-state products CH3OO(X 2A″) + H(2S) in addition to adiabatic dissociation in the first excited singlet state, S1, correlating to products CH3OO(1 2A') + H(2S). The computed translational energy of the majority of the OH products is found to be high, distributed in the range of 70 to 100 kcal/mol, indicating that the dissociation takes place on a strong repulsive potential energy surface. This finding is consistent with the nature of the experimentally derived translational energy distribution of OH with an average translational energy of 67 kcal/mol after the excitation of CH3OOH at 193 nm.
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Affiliation(s)
- Prabhash Mahata
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Biswajit Maiti
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
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6
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Kim MS, Lee C, Kim JH. Occurrence of unknown reactive species in UV/H 2O 2 system leading to false interpretation of hydroxyl radical probe reactions. WATER RESEARCH 2021; 201:117338. [PMID: 34171647 DOI: 10.1016/j.watres.2021.117338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/29/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The UV/H2O2 process is a benchmark advanced oxidation process (AOP) that in situ generates highly reactive and nonselective hydroxyl radical (•OH) to oxidatively destroy a wide range of organic compounds. Accurately quantifying the concentration of short-lived •OH is essential to predict process performance, optimize the operation parameters, and compare with other process options. The •OH concentration is typically measured using organic probe molecules that react with •OH but not with other oxidants. In the extremely well-characterized UV/H2O2 system in which •OH is proven to be the dominant oxidant, using photolysis-resistant probes such as benzoic acid and its derivatives is a widely agreed and practiced norm. We herein report that certain •OH probe compounds can be degraded in UV/H2O2 system by unknown reactive species that has not been reported in the past. Several common organic probes, particularly p-substituted benzoic acid compounds (i.e., p-hydroxybenzoic acid, p-chlorobenzoic acid, and p-phthalic acid), were found to be vulnerable to attack by the unknown reactive species, leading to false quantification of •OH concentration under high radical scavenging conditions. Lines of evidence obtained from a series of •OH scavenging experiments performed under various conditions (i.e., different concentrations of H2O2, •OH probe compounds, and dissolved oxygen) point toward excited state H2O2. The results from this study suggest the importance of using appropriate •OH probe compounds in mechanistic studies and needs for considering the unidentified role of excited state of H2O2 on the UV/H2O2 process and related AOPs.
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Affiliation(s)
- Min Sik Kim
- Department of Environmental Engineering and Soil Environment Research Center, Jeonbuk National University, Jeonju, Jeollabukdo 54896, Republic of Korea; School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea; Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Changha Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea.
| | - Jae-Hong Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States.
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7
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Ruiz-López MF, Martins-Costa MTC, Francisco JS, Anglada JM. Tight electrostatic regulation of the OH production rate from the photolysis of hydrogen peroxide adsorbed on surfaces. Proc Natl Acad Sci U S A 2021; 118:e2106117118. [PMID: 34290148 PMCID: PMC8325346 DOI: 10.1073/pnas.2106117118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Recently, experimental and theoretical works have reported evidence indicating that photochemical processes may significantly be accelerated at heterogeneous interfaces, although a complete understanding of the phenomenon is still lacking. We have carried out a theoretical study of interface and surface effects on the photochemistry of hydrogen peroxide (H2O2) using high-level ab initio methods and a variety of models. Hydrogen peroxide is an important oxidant that decomposes in the presence of light, forming two OH radicals. This elementary photochemical process has broad interest and is used in many practical applications. Our calculations show that it can drastically be affected by heterogeneous interfaces. Thus, compared to gas phase, the photochemistry of H2O2 appears to be slowed on the surface of apolar or low-polar surfaces and, in contrast, hugely accelerated on ionic surfaces or the surface of aqueous electrolytes. We give particular attention to the case of the neat air-water interface. The calculated photolysis rate is similar to the gas phase, which stems from the compensation of two opposite effects, the blue shift of the n→σ* absorption band and the increase of the absorption intensity. Nevertheless, due to the high affinity of H2O2 for the air-water interface, the predicted OH production rate is up to five to six orders of magnitude larger. Overall, our results show that the photochemistry of H2O2 in heterogeneous environments is greatly modulated by the nature of the surface, and this finding opens interesting new perspectives for technological and biomedical applications, and possibly in various atmospheres.
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Affiliation(s)
- Manuel F Ruiz-López
- Laboratoire de Physique et Chimie Théoriques, CNRS UMR 7019, University of Lorraine, 54506 Vandoeuvre-lès-Nancy, France;
| | - Marilia T C Martins-Costa
- Laboratoire de Physique et Chimie Théoriques, CNRS UMR 7019, University of Lorraine, 54506 Vandoeuvre-lès-Nancy, France
| | - Joseph S Francisco
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104;
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Josep M Anglada
- Departament de Química Biològica, Institut de Química Avançada de Catalunya, Consejo Superior de Investigaciones Científicas, E-08034 Barcelona, Spain
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8
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Shi G, Song J, Tian P, Li Z. Theoretical study of the reactions of hydrogen atom with methyl and ethyl hydroperoxides. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1919324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Gai Shi
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Jinou Song
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Pengzhen Tian
- College of Mathematics and Information Science, Hebei University, Baoding, People’s Republic of China
| | - Zhijun Li
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
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9
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10
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Masumoto I, Washida N, Inomata S, Imamura T, Muraoka A, Yamashita K. Laser-induced fluorescence of the trans-CHBrCHO radical. J Chem Phys 2020; 153:104301. [PMID: 32933291 DOI: 10.1063/5.0019234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new laser-induced fluorescence spectrum was observed in the region of 350 nm-360 nm. The spectrum was observed in the reaction between the CHBrCHBr and OH radicals and in the reaction of CHBrCHBr and CH2CHBr with atomic oxygen O(3P). The spectrum was assigned to the B̃--X̃ transition of the trans-CHBrCHO (trans-2-bromovinoxy) radical. The B̃--X̃ electronic transition energy (T0) was 28 542 cm-1, which was 242 cm-1 lower than that of the unsubstituted vinoxy radical (CH2CHO). From an analysis of the laser-induced single vibronic level fluorescence aided by ab initio calculations, some of the vibrational frequencies were assigned to the ground electronic state ν3 (C-O str.) = 1581 cm-1, ν6 (C-C str.) = 1130 cm-1, and ν8 (C-C-O bend.) = 409 cm-1. The fluorescence lifetimes of the excited B̃ state were 35 ns-75 ns, depending on the excited vibrational modes, implying that predissociation had accelerated as the energy level (v') increased.
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Affiliation(s)
- Ichiro Masumoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Nobuaki Washida
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Satoshi Inomata
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Takashi Imamura
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Azusa Muraoka
- Department of Mathematical and Physical Sciences, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Koichi Yamashita
- Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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11
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Anglada JM, Martins-Costa MTC, Francisco JS, Ruiz-López MF. Photoinduced Oxidation Reactions at the Air-Water Interface. J Am Chem Soc 2020; 142:16140-16155. [PMID: 32833454 DOI: 10.1021/jacs.0c06858] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chemistry on water is a fascinating area of research. The surface of water and the interfaces between water and air or hydrophobic media represent asymmetric environments with unique properties that lead to unexpected solvation effects on chemical and photochemical processes. Indeed, the features of interfacial reactions differ, often drastically, from those of bulk-phase reactions. In this Perspective, we focus on photoinduced oxidation reactions, which have attracted enormous interest in recent years because of their implications in many areas of chemistry, including atmospheric and environmental chemistry, biology, electrochemistry, and solar energy conversion. We have chosen a few representative examples of photoinduced oxidation reactions to focus on in this Perspective. Although most of these examples are taken from the field of atmospheric chemistry, they were selected because of their broad relevance to other areas. First, we outline a series of processes whose photochemistry generates hydroxyl radicals. These OH precursors include reactive oxygen species, reactive nitrogen species, and sulfur dioxide. Second, we discuss processes involving the photooxidation of organic species, either directly or via photosensitization. The photochemistry of pyruvic acid and fatty acid, two examples that demonstrate the complexity and versatility of this kind of chemistry, is described. Finally, we discuss the physicochemical factors that can be invoked to explain the kinetics and thermodynamics of photoinduced oxidation reactions at aqueous interfaces and analyze a number of challenges that need to be addressed in future studies.
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Affiliation(s)
- Josep M Anglada
- Departament de Química Biològica, IQAC-CSIC, c/Jordi Girona 18, E-08034 Barcelona, Spain
| | - Marilia T C Martins-Costa
- Laboratoire de Physique et Chimie Théoriques, UMR CNRS 7019, University of Lorraine, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy, France
| | - Joseph S Francisco
- Department of Earth and Environmental Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-631, United States
| | - Manuel F Ruiz-López
- Laboratoire de Physique et Chimie Théoriques, UMR CNRS 7019, University of Lorraine, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy, France
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12
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Prlj A, Ibele LM, Marsili E, Curchod BFE. On the Theoretical Determination of Photolysis Properties for Atmospheric Volatile Organic Compounds. J Phys Chem Lett 2020; 11:5418-5425. [PMID: 32543205 PMCID: PMC7372557 DOI: 10.1021/acs.jpclett.0c01439] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Volatile organic compounds (VOCs) are ubiquitous atmospheric molecules that generate a complex network of chemical reactions in the troposphere, often triggered by the absorption of sunlight. Understanding the VOC composition of the atmosphere relies on our ability to characterize all of their possible reaction pathways. When considering reactions of (transient) VOCs with sunlight, the availability of photolysis rate constants, utilized in general atmospheric models, is often out of experimental reach due to the unstable nature of these molecules. Here, we show how recent advances in computational photochemistry allow us to calculate in silico the different ingredients of a photolysis rate constant, namely, the photoabsorption cross-section and wavelength-dependent quantum yields. The rich photochemistry of tert-butyl hydroperoxide, for which experimental data are available, is employed to test our protocol and highlight the strengths and weaknesses of different levels of electronic structure and nonadiabatic molecular dynamics to study the photochemistry of (transient) VOCs.
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13
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Medeiros DJ, Robertson SH, Blitz MA, Seakins PW. Direct Trace Fitting of Experimental Data Using the Master Equation: Testing Theory and Experiments on the OH + C 2H 4 Reaction. J Phys Chem A 2020; 124:4015-4024. [PMID: 32353235 DOI: 10.1021/acs.jpca.0c02132] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Laser flash photolysis coupled with laser-induced fluorescence observation of OH has been used to observe the equilibration of OH + C2H4 ↔ HOC2H4 over the temperature range 563-723 K and pressures of bath gas (N2) from 58 to 250 Torr. The time-resolved OH traces have been directly and globally fitted with a master equation in order to extract ΔRH00, the binding energy of the HOC2H4 adduct, with respect to reagents. The global approach allows the role that OH abstraction plays at higher temperatures to be identified. The resultant value ofΔRH00, 111.8 kJ mol-1, is determined to be better than 2 kJ mol-1 and is in agreement with our ab initio calculations (carried out at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level), 111.4 kJ mol-1, and other state of the art calculations. Parameters for the abstraction channel are also in good agreement with previous experimental studies. To effect this analysis, the MESMER master equation code was extended to directly incorporate secondary chemistry: diffusional loss from the observation region and reaction with the photolytic precursor. These extensions, which, among other things, resolve issues related to the merging of chemically significant and internal energy relaxation eigenvalues, are presented.
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Affiliation(s)
| | - S H Robertson
- Dassault Systèmes, 334 Science Park, Milton Road, Cambridge CB4 0WN, United Kingdom
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14
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Zhang T, Wen M, Zeng Z, Lu Y, Wang Y, Wang W, Shao X, Wang Z, Makroni L. Effect of NH 3 and HCOOH on the H 2O 2 + HO → HO 2 + H 2O reaction in the troposphere: competition between the one-step and stepwise mechanisms. RSC Adv 2020; 10:9093-9102. [PMID: 35496523 PMCID: PMC9050117 DOI: 10.1039/d0ra00024h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/13/2020] [Indexed: 11/21/2022] Open
Abstract
The H2O2 + HO → HO2 + H2O reaction is an important reservoir for both radicals of HO and HO2 catalyzing the destruction of O3. Here, this reaction assisted by NH3 and HCOOH catalysts was explored using the CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ method and canonical variational transition state theory with small curvature tunneling. Two possible sets of mechanisms, (i) one-step routes and (ii) stepwise processes, are possible. Our results show that in the presence of both NH3 and HCOOH catalysts under relevant atmospheric temperature, mechanism (i) is favored both energetically and kinetically than the corresponding mechanism (ii). At 298 K, the relative rate for mechanism (i) in the presence of NH3 (10, 2900 ppbv) and HCOOH (10 ppbv) is respectively 3–5 and 2–4 orders of magnitude lower than that of the water-catalyzed reaction. This is due to a comparatively lower concentration of NH3 and HCOOH than H2O which indicates the positive water effect under atmospheric conditions. Although NH3 and HCOOH catalysts play a negligible role in the reservoir for both radicals of HO and HO2 catalyzing the destruction of O3, the current study provides a comprehensive example of how acidic and basic catalysts assisted the gas-phase reactions. The H2O2 + HO → HO2 + H2O reaction is an important reservoir for both radicals of HO and HO2 catalyzing the destruction of O3.![]()
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Affiliation(s)
- Tianlei Zhang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Mingjie Wen
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Zhaopeng Zeng
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Yousong Lu
- Key Laboratory for Macromolecular Science of Shaanxi Province
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- Xi'an
- P. R. China
| | - Yan Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Wei Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Xianzhao Shao
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Zhiyin Wang
- Shaanxi Key Laboratory of Catalysis
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong
- P. R. China
| | - Lily Makroni
- Key Laboratory for Macromolecular Science of Shaanxi Province
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- Xi'an
- P. R. China
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15
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Masumoto I, Washida N, Inomata S, Muraoka A, Yamashita K. Laser-induced fluorescence of the CHFCHO radical and reaction of OH radicals with halogenated ethylenes. J Chem Phys 2019; 150:174302. [PMID: 31067886 DOI: 10.1063/1.5090524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new laser-induced fluorescence spectrum of the 2-fluorovinoxy (CHFCHO) radical was first observed around 335 nm. The radical was produced in the reaction of an OH radical with 1,2-difluoroethylene (CHF=CHF). A single weak band was observed, which was assigned to the 00 0 band of the B̃-X̃ transition of the trans-CHFCHO radical. The B̃←X̃ electronic transition energy (T0) for trans-CHFCHO was 29 871 cm-1, which was just 3 cm-1 lower than that of its isomer, the 1-fluorovinoxy (CH2CFO) radical. The fluorescence lifetime at 29 871 cm-1 was shorter than 20 ns. This means that strong predissociation is probable at v' = 0 in the excited B̃ state of trans-CHFCHO. From an analysis of the dispersed fluorescence spectrum, some of the vibrational frequencies can be assigned for the ground electronic state: ν3 = 1557 cm-1 (C-O stretch), ν7 = 1162 cm-1 (C-C stretch), and ν8 = 541 cm-1 (CCO bend). These vibrational assignments were supported by ab initio calculations. The structure of the C-C-O skeleton and the spectroscopic character of trans-CHFCHO were close to those of CHClCHO and CH2CHO than those of CH2CFO. For the reaction of CH2=CHF with O(3P), the formation of both the regioisomeric radicals, i.e., 1- and 2-fluorovinoxy radicals, was confirmed. The regioselectivity of the oxygen atom added to the double bond of monofluoroethylene is discussed.
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Affiliation(s)
- Ichiro Masumoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Nobuaki Washida
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Satoshi Inomata
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Azusa Muraoka
- Department of Mathematical and Physical Sciences, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Koichi Yamashita
- Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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16
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Ravishankara AR, Pele AL, Zhou L, Ren Y, Zogka A, Daële V, Idir M, Brown SS, Romanias MN, Mellouki A. Atmospheric loss of nitrous oxide (N2O) is not influenced by its potential reactions with OH and NO3radicals. Phys Chem Chem Phys 2019; 21:24592-24600. [DOI: 10.1039/c9cp04818a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rate coefficient for the possible reaction of OH and NO3radical with N2O are shown to be, respectively, <1 × 10−17and <5 × 10−20cm3molecule−1s−1. They are too low to contribute significantly to the atmospheric removal of N2O.
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Affiliation(s)
- A. R. Ravishankara
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Anne-Laure Pele
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Li Zhou
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Yangang Ren
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Antonia Zogka
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Véronique Daële
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Mahmoud Idir
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
| | - Steven S. Brown
- National Oceanic and Atmospheric Administration
- Earth System Research Laboratory
- Chemical Sciences Division
- Boulder
- USA
| | | | - Abdelwahid Mellouki
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement/OSUC
- CNRS
- 45071 Orléans Cedex 02
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17
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Lockhart JP, Gross EC, Sears TJ, Hall GE. Investigating the photodissociation of H2O2 using frequency modulation laser absorption spectroscopy to monitor radical products. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Jiang H, Jang M. Dynamic Oxidative Potential of Atmospheric Organic Aerosol under Ambient Sunlight. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7496-7504. [PMID: 29772167 DOI: 10.1021/acs.est.8b00148] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The atmospheric process dynamically changes the chemical compositions of organic aerosol (OA), thereby complicating the interpretation of its health effects. In this study, the dynamic evolution of the oxidative potential of various OA was studied, including wood combustion particles and secondary organic aerosols (SOA) generated from different hydrocarbons (i.e., gasoline, toluene, isoprene, and α-pinene). The oxidative potential of OA at different aging stages was subsequently measured by the dithiothreitol consumption (DTTm, mass normalized). We hypothesized that DTT consumptions by OA were modulated by catalytic particulate oxidizers (e.g., quinones), noncatalytic particulate oxidizers (e.g., organic hydroperoxides and peroxyacyl nitrates) and electron-deficient alkenes. The results of this study showed that the oxidative potential of OA decreased after an extended period of aging due to the decomposition of particulate oxidizers and electron-deficient alkenes. Quinones (GC-MS data) partially attributed to the DTTm of fresh wood smoke particles but rapidly dropped with aging. In biogenic SOA, organic hydroperoxides (4-nitrophenyl boronic acid assay) exclusively accounted for DTTm and decreased with aging. The DTTm of aromatic SOA, mainly comprising organic hydroperoxides and electron-deficient alkenes (FTIR data), was shortly elevated during the early atmospheric process; however, it showed a noticeable decrease (32-75%) for a long period of aging. We concluded that fresh or moderately aged OA are more reactive to a sulfhydryl group than highly aged OA.
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Affiliation(s)
- Huanhuan Jiang
- Department of Environmental Engineering Sciences, Engineering School of Sustainable Infrastructure and Environment , University of Florida , Gainesville , Florida 32608 , United States
| | - Myoseon Jang
- Department of Environmental Engineering Sciences, Engineering School of Sustainable Infrastructure and Environment , University of Florida , Gainesville , Florida 32608 , United States
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19
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Martins-Costa MTC, Anglada JM, Francisco JS, Ruiz-López MF. Impacts of cloud water droplets on the OH production rate from peroxide photolysis. Phys Chem Chem Phys 2018; 19:31621-31627. [PMID: 29164201 DOI: 10.1039/c7cp06813a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the difference between observed and modeled concentrations of HOx radicals in the troposphere is a current major issue in atmospheric chemistry. It is widely believed that existing atmospheric models miss a source of such radicals and several potential new sources have been proposed. In recent years, interest has increased on the role played by cloud droplets and organic aerosols. Computer modeling of ozone photolysis, for instance, has shown that atmospheric aqueous interfaces accelerate the associated OH production rate by as much as 3-4 orders of magnitude. Since methylhydroperoxide is a main source and sink of HOx radicals, especially at low NOx concentrations, it is fundamental to assess what is the influence of clouds on its chemistry and photochemistry. In this study, computer simulations for the photolysis of methylhydroperoxide at the air-water interface have been carried out showing that the OH production rate is severely enhanced, reaching a comparable level to ozone photolysis.
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Affiliation(s)
- M T C Martins-Costa
- SRSMC, University of Lorraine, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy, France.
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20
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Assaf E, Tanaka S, Kajii Y, Schoemaecker C, Fittschen C. Rate constants of the reaction of C2–C4 peroxy radicals with OH radicals. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.06.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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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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22
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Li Y, Wang N, Wang C, Wang X, Zhang J, Wang L. Theoretical study on the unimolecular decomposition of 2-chlorinated ethyl hydroperoxide. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2016. [DOI: 10.1142/s0219633616500085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chlorine-containing organic compounds have been of major interest since such compounds would serve as temporary reservoirs for HOX, ROX and ClOX radicals. Moreover, it would transport chlorine species to the atmosphere and stratosphere. However, limited studies have been performed on the 2-chlorinated ethyl hydroperoxide. In this work, the mechanism of unimolecular dissociation of 2-chlorinated ethyl hydroperoxide is theoretically studied. The equilibrium structures are optimized at the Boese–Martin for kinetics (BMK) level. And the energies are further refined at the Balanced multi-coefficient correlation-coupled cluster theory with single and double excitations (BMC-CCSD) level on the basis of the optimized geometries. Fifteen reaction channels are finally confirmed including the direct C–O, O–O, O–H, and C–C bond cleavage or the H2-, H2O-, H2O2-, and CH3Cl-elimination.
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Affiliation(s)
- Ya Li
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Na Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Chunzhang Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Xin Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Jinglai Zhang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Li Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
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23
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Gligorovski S, Strekowski R, Barbati S, Vione D. Environmental Implications of Hydroxyl Radicals (•OH). Chem Rev 2015; 115:13051-92. [DOI: 10.1021/cr500310b] [Citation(s) in RCA: 737] [Impact Index Per Article: 81.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sasho Gligorovski
- Aix-Marseille
Université, CNRS, LCE UMR 7376, 13331 Marseilles, France
| | - Rafal Strekowski
- Aix-Marseille
Université, CNRS, LCE UMR 7376, 13331 Marseilles, France
| | - Stephane Barbati
- Aix-Marseille
Université, CNRS, LCE UMR 7376, 13331 Marseilles, France
| | - Davide Vione
- Dipartimento
di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy
- Centro
Interdipartimentale NatRisk, Università di Torino, Via L. Da
Vinci 44, 10095 Grugliasco, Italy
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24
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Kerr KE, Alecu IM, Thompson KM, Gao Y, Marshall P. Experimental and Computational Studies of the Kinetics of the Reaction of Atomic Hydrogen with Methanethiol. J Phys Chem A 2015; 119:7352-60. [DOI: 10.1021/jp512966a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine E. Kerr
- Department
of Chemistry and
Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5017, United States
| | - Ionut M. Alecu
- Department
of Chemistry and
Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5017, United States
| | - Kristopher M. Thompson
- Department
of Chemistry and
Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5017, United States
| | - Yide Gao
- Department
of Chemistry and
Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5017, United States
| | - Paul Marshall
- Department
of Chemistry and
Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5017, United States
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25
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26
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Morajkar P, Bossolasco A, Schoemaecker C, Fittschen C. Photolysis of CH3CHO at 248 nm: Evidence of triple fragmentation from primary quantum yield of CH3 and HCO radicals and H atoms. J Chem Phys 2014; 140:214308. [DOI: 10.1063/1.4878668] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Liu FY, Long ZW, Tan XF, Long B. Theoretical investigation on mechanisms and kinetics of the reactions of Cl atom with CH3OOH and CH3CH2OOH. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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29
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François-Heude A, Richaud E, Desnoux E, Colin X. Influence of temperature, UV-light wavelength and intensity on polypropylene photothermal oxidation. Polym Degrad Stab 2014. [DOI: 10.1016/j.polymdegradstab.2013.12.038] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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31
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Hsieh S, Vushe R, Tun YT, Vallejo JL. Trends in organic hydroperoxide photodissociation and absorption cross sections between 266 and 377 nm. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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32
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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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33
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Kahan TF, Washenfelder RA, Vaida V, Brown SS. Cavity-enhanced measurements of hydrogen peroxide absorption cross sections from 353 to 410 nm. J Phys Chem A 2012; 116:5941-7. [PMID: 22225472 DOI: 10.1021/jp2104616] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report near-ultraviolet and visible absorption cross sections of hydrogen peroxide (H(2)O(2)) using incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS), a recently developed, high-sensitivity technique. The measurements reported here span the range of 353-410 nm and extend published electronic absorption cross sections by 60 nm to absorption cross sections below 1 × 10(-23) cm(2) molecule(-1). We have calculated photolysis rate constants for H(2)O(2) in the lower troposphere at a range of solar zenith angles by combining the new measurements with previously reported data at wavelengths shorter than 350 nm. We predict that photolysis at wavelengths longer than those included in the current JPL recommendation may account for up to 28% of the total hydroxyl radical (OH) production from H(2)O(2) photolysis under some conditions. Loss of H(2)O(2) via photolysis may be of the same order of magnitude as reaction with OH and dry deposition in the lower atmosphere; these processes have very different impacts on HO(x) loss and regeneration.
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Affiliation(s)
- Tara F Kahan
- Department of Chemistry and Biochemistry, University of Colorado, Campus Box 215, Boulder, Colorado 80309, United States
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34
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Epstein SA, Shemesh D, Tran VT, Nizkorodov SA, Gerber RB. Absorption Spectra and Photolysis of Methyl Peroxide in Liquid and Frozen Water. J Phys Chem A 2012; 116:6068-77. [DOI: 10.1021/jp211304v] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Scott A. Epstein
- Department of Chemistry, University of California, Irvine, California 92697,
United States
| | - Dorit Shemesh
- Department
of Physical Chemistry
and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904, Israel
| | - Van T. Tran
- Department of Chemistry, University of California, Irvine, California 92697,
United States
| | - Sergey A. Nizkorodov
- Department of Chemistry, University of California, Irvine, California 92697,
United States
| | - R. Benny Gerber
- Department of Chemistry, University of California, Irvine, California 92697,
United States
- Department
of Physical Chemistry
and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904, Israel
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35
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Hsieh S, Thida T, Nyamumbo MK, Smith KA, Naamad N, Linck RG. O–H Stretch Overtone Excitation of Ethyl Hydroperoxide Conformers. J Phys Chem A 2011; 115:14040-4. [DOI: 10.1021/jp208467f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Shizuka Hsieh
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
| | - Thida Thida
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
| | - Margaret K. Nyamumbo
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
| | - Kelly A. Smith
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
| | - Noah Naamad
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
| | - Robert G. Linck
- Chemistry Department, Smith College, Northampton, Massachusetts 01063, United States
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36
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Jain C, Schoemaecker C, Fittschen C. Yield of HO2 Radicals in the OH-Initiated Oxidation of SO2. ACTA ACUST UNITED AC 2011. [DOI: 10.1524/zpch.2011.0169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The HO2 radical yield in the OH initiated oxidation of SO2 has been determined by direct observation of HO2 concentration time profiles following the 248 nm photolysis of H2O2/SO2/O2 mixtures. Initial OH radical concentrations have been deduced from a fit of the absolute HO2 concentration time profiles after 248 nm photolysis of H2O2 in the absence of SO2, an increase in the HO2 concentration upon addition of SO2 to this reaction mixture is observed and can be explained by a decrease of HO
x
-radical losses due to a faster decay of OH radicals in the presence of SO2. Simulations of theses profiles using recommended rate constants in a simple model are in agreement with an HO2-yield of 1.0 ± 0.1 from the OH initiated oxidation of SO2.
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Affiliation(s)
- Chaithanya Jain
- Université Lille Nord de France, Physico-Chimie des Processus de Combustion, Villeneuve d'Ascq Cedex, Frankreich
| | - Coralie Schoemaecker
- Université Lille Nord de France, Physico-Chimie des Processus de Combustion, Villeneuve d'Ascq Cedex, Frankreich
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37
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Jain C, Morajkar P, Schoemaecker C, Viskolcz B, Fittschen C. Measurement of Absolute Absorption Cross Sections for Nitrous Acid (HONO) in the Near-Infrared Region by the Continuous Wave Cavity Ring-Down Spectroscopy (cw-CRDS) Technique Coupled to Laser Photolysis. J Phys Chem A 2011; 115:10720-8. [DOI: 10.1021/jp203001y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chaithanya Jain
- PhysicoChimie des Processus de Combustion et de l′Atmosphère, Université Lille Nord de France, PC2A CNRS Université Lille 1, UMR 8522, F-59650 Villeneuve d′Ascq, France
| | - Pranay Morajkar
- PhysicoChimie des Processus de Combustion et de l′Atmosphère, Université Lille Nord de France, PC2A CNRS Université Lille 1, UMR 8522, F-59650 Villeneuve d′Ascq, France
| | - Coralie Schoemaecker
- PhysicoChimie des Processus de Combustion et de l′Atmosphère, Université Lille Nord de France, PC2A CNRS Université Lille 1, UMR 8522, F-59650 Villeneuve d′Ascq, France
| | - Bela Viskolcz
- Department of Chemistry and Chemical Informatics, Faculty of Education, University of Szeged, Szeged, Boldogasszony sgt. 6, Hungary 6725
| | - Christa Fittschen
- PhysicoChimie des Processus de Combustion et de l′Atmosphère, Université Lille Nord de France, PC2A CNRS Université Lille 1, UMR 8522, F-59650 Villeneuve d′Ascq, France
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38
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Gao SS, Abbatt JPD. Kinetics and Mechanism of OH Oxidation of Small Organic Dicarboxylic Acids in Ice: Comparison to Behavior in Aqueous Solution. J Phys Chem A 2011; 115:9977-86. [DOI: 10.1021/jp202478w] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shawna S. Gao
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6
| | - Jonathan P. D. Abbatt
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6
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39
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Influence of initial parent vibrational excitation in promoting two-photon absorption in HOOH and CH3OOH. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.06.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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40
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Domagal-Goldman SD, Meadows VS, Claire MW, Kasting JF. Using biogenic sulfur gases as remotely detectable biosignatures on anoxic planets. ASTROBIOLOGY 2011; 11:419-41. [PMID: 21663401 PMCID: PMC3133782 DOI: 10.1089/ast.2010.0509] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We used one-dimensional photochemical and radiative transfer models to study the potential of organic sulfur compounds (CS(2), OCS, CH(3)SH, CH(3)SCH(3), and CH(3)S(2)CH(3)) to act as remotely detectable biosignatures in anoxic exoplanetary atmospheres. Concentrations of organic sulfur gases were predicted for various biogenic sulfur fluxes into anoxic atmospheres and were found to increase with decreasing UV fluxes. Dimethyl sulfide (CH(3)SCH(3), or DMS) and dimethyl disulfide (CH(3)S(2)CH(3), or DMDS) concentrations could increase to remotely detectable levels, but only in cases of extremely low UV fluxes, which may occur in the habitable zone of an inactive M dwarf. The most detectable feature of organic sulfur gases is an indirect one that results from an increase in ethane (C(2)H(6)) over that which would be predicted based on the planet's methane (CH(4)) concentration. Thus, a characterization mission could detect these organic sulfur gases-and therefore the life that produces them-if it could sufficiently quantify the ethane and methane in the exoplanet's atmosphere.
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41
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Chen D, Jin H, Wang Z, Zhang L, Qi F. Unimolecular decomposition of ethyl hydroperoxide: ab initio/Rice-Ramsperger-Kassel-Marcus theoretical prediction of rate constants. J Phys Chem A 2011; 115:602-11. [PMID: 21207985 DOI: 10.1021/jp1099305] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alkyl hydroperoxides are found to be important intermediates in the combustion and oxidation processes of hydrocarbons. However, studies of ethyl hydroperoxide (CH(3)CH(2)OOH) are limited. In this work, kinetics and mechanisms for unimolecular decomposition of CH(3)CH(2)OOH have been investigated. The potential energy surface of decomposition reactions have first been predicted at the CCSD(T)/6-311+G(3df,2p)//B3LYP/6-311G(d,p) level. The results show that the formation of CH(3)CH(2)O + OH via O-O direct bond dissociation is dominant, the branching ratio of which is over 99% in the whole temperature range from 300 to 1000 K, and its rate constant can be expressed as k1 = 9.26 × 10(52)T(-11.91)exp(-26879/T) s(-1) at 1 atm. The rate constants of the reaction CH(3)CH(2)OOH → CH(3)CH(2)O + OH at different temperatures and pressures have been calculated, which can help us to comprehend the reactions of CH(3)CH(2)OOH at experimental conditions.
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Affiliation(s)
- Dongna Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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42
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Riffault V, Clark JM, Hansen JC, Ravishankara AR, Burkholder JB. Temperature‐Dependent Rate Coefficients and Theoretical Calculations for the OH+Cl
2
O Reaction. Chemphyschem 2010; 11:4060-8. [DOI: 10.1002/cphc.201000420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Véronique Riffault
- Earth System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305‐3328 (USA), Fax: (+1) 303 497 5373
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 (USA)
- Ecole des Mines de Douai, Département Chimie et Environnement, 941 rue Charles Bourseul, BP 10838, 59508 Douai cedex (France)
| | - Jared M. Clark
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602 (USA)
| | - Jaron C. Hansen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602 (USA)
| | - A. R. Ravishankara
- Earth System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305‐3328 (USA), Fax: (+1) 303 497 5373
| | - James B. Burkholder
- Earth System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305‐3328 (USA), Fax: (+1) 303 497 5373
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43
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Noell AC, Alconcel LS, Robichaud DJ, Okumura M, Sander SP. Near-infrared kinetic spectroscopy of the HO2 and C2H5O2 self-reactions and cross reactions. J Phys Chem A 2010; 114:6983-95. [PMID: 20524693 DOI: 10.1021/jp912129j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The self-reactions and cross reactions of the peroxy radicals C2H5O2 and HO2 were monitored using simultaneous independent spectroscopic probes to observe each radical species. Wavelength modulation (WM) near-infrared (NIR) spectroscopy was used to detect HO2, and UV absorption monitored C2H5O2. The temperature dependences of these reactions were investigated over a range of interest to tropospheric chemistry, 221-296 K. The Arrhenius expression determined for the cross reaction, k2(T) = (6.01(-1.47)(+1.95)) x 10(-13) exp((638 +/- 73)/T) cm3 molecules(-1) s(-1) is in agreement with other work from the literature. The measurements of the HO2 self-reaction agreed with previous work from this lab and were not further refined. The C2H5O2 self-reaction is complicated by secondary production of HO2. This experiment performed the first direct measurement of the self-reaction rate constant, as well as the branching fraction to the radical channel, in part by measurement of the secondary HO2. The Arrhenius expression for the self-reaction rate constant is k3(T) = (1.29(-0.27)(+0.34)) x 10(-13)exp((-23 +/- 61)/T) cm3 molecules(-1) s(-1), and the branching fraction value is alpha = 0.28 +/- 0.06, independent of temperature. These values are in disagreement with previous measurements based on end product studies of the branching fraction. The results suggest that better characterization of the products from RO2 self-reactions are required.
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Affiliation(s)
- A C Noell
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, M/S 183-901, Pasadena, California 91109, USA
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Kamboures MA, Nizkorodov SA, Gerber RB. Ultrafast photochemistry of methyl hydroperoxide on ice particles. Proc Natl Acad Sci U S A 2010; 107:6600-4. [PMID: 19846778 PMCID: PMC2872419 DOI: 10.1073/pnas.0907922106] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Simulations show that photodissociation of methyl hydroperoxide, CH(3)OOH, on water clusters produces a surprisingly wide range of products on a subpicosecond time scale, pointing to the possibility of complex photodegradation pathways for organic peroxides on aerosols and water droplets. Dynamics are computed at several excitation energies at 50 K using a semiempirical PM3 potential surface. CH(3)OOH is found to prefer the exterior of the cluster, with the CH(3)O group sticking out and the OH group immersed within the cluster. At atmospherically relevant photodissociation wavelengths the OH and CH(3)O photofragments remain at the surface of the cluster or embedded within it. However, none of the 25 completed trajectories carried out at the atmospherically relevant photodissociation energies led to recombination of OH and CH(3)O to form CH(3)OOH. Within the limited statistics of the available trajectories the predicted yield for the recombination is zero. Instead, various reactions involving the initial fragments and water promptly form a wide range of stable molecular products such as CH(2)O, H(2)O, H(2), CO, CH(3)OH, and H(2)O(2).
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Affiliation(s)
- M. A. Kamboures
- Department of Chemistry, University of California, Irvine, CA 92697-2025 and
| | - S. A. Nizkorodov
- Department of Chemistry, University of California, Irvine, CA 92697-2025 and
| | - R. B. Gerber
- Department of Chemistry, University of California, Irvine, CA 92697-2025 and
- Institute of Chemistry and Fritz Haber Center, Hebrew University, Jerusalem 91904, Israel
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45
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Baasandorj M, Papanastasiou DK, Talukdar RK, Hasson AS, Burkholder JB. (CH3)3COOH (tert-butyl hydroperoxide): OH reaction rate coefficients between 206 and 375 K and the OH photolysis quantum yield at 248 nm. Phys Chem Chem Phys 2010; 12:12101-11. [DOI: 10.1039/c0cp00463d] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Pinho PG, Lemos LT, Pio CA, Evtyugina MG, Nunes TV, Jenkin ME. Detailed chemical analysis of regional-scale air pollution in western Portugal using an adapted version of MCM v3.1. THE SCIENCE OF THE TOTAL ENVIRONMENT 2009; 407:2024-2038. [PMID: 19101710 DOI: 10.1016/j.scitotenv.2008.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 10/17/2008] [Accepted: 11/03/2008] [Indexed: 05/27/2023]
Abstract
A version of the Master Chemical Mechanism (MCM) v3.1, refined on the basis of recent chamber evaluations, has been incorporated into a Photochemical Trajectory Model (PTM) and applied to the simulation of boundary layer photochemistry in the Portuguese west coast region. Comparison of modelled concentrations of ozone and a number of other species (NO(x) and selected hydrocarbons and organic oxygenates) was carried out, using data from three connected sites on two case study days when well-defined sea breeze conditions were established. The ozone concentrations obtained through the application of the PTM are a good approximation to the measured values, the average difference being ca. 15%, indicating that the model was acceptable for evaluation of the details of the chemical processing. The detailed chemistry is examined, allowing conclusions to be drawn concerning chemical interferences in the measurements of NO(2), and in relation to the sensitivity of ozone formation to changes in ambient temperature. Three important, and comparable, contributions to the temperature sensitivity are identified and quantified, namely (i) an effect of increasing biogenic emissions with temperature; (ii) an effect of increasing ambient water vapour concentration with temperature, and its influence on radical production; and (iii) an increase in VOC oxidation chain lengths resulting from the temperature-dependence of the kinetic parameters, particularly in relation to the stability of PAN and its higher analogues. The sensitivity of the simulations to the refinements implemented into MCM v3.1 are also presented and discussed.
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Affiliation(s)
- P G Pinho
- Department of Environment, Polytechnic Institute of Viseu, 3504-510 Viseu, Portugal.
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Matthews J, Martínez-Avilés M, Francisco JS, Sinha A. Probing OH stretching overtones of CH3OOH through action spectroscopy: Influence of dipole moment dependence on HOOC torsion. J Chem Phys 2008; 129:074316. [DOI: 10.1063/1.2967185] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Eisfeld W, Francisco JS. Excited states and photodissociation of hydroxymethyl hydroperoxide. J Chem Phys 2008; 128:174304. [DOI: 10.1063/1.2909547] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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49
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Closser KD, Vogelhuber KM, Hsieh S. Vibrational−Torsional Excitation and Direct Overtone Photodissociation of Ethyl Hydroperoxide at 5νOH. J Phys Chem A 2008; 112:1238-44. [DOI: 10.1021/jp076803r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kristina D. Closser
- Department of Chemistry, Clark Science Center, Smith College, Northampton, Massachusetts 01063
| | - Kristen M. Vogelhuber
- Department of Chemistry, Clark Science Center, Smith College, Northampton, Massachusetts 01063
| | - Shizuka Hsieh
- Department of Chemistry, Clark Science Center, Smith College, Northampton, Massachusetts 01063
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50
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Carr SA, Baeza-Romero MT, Blitz MA, Price BJS, Seakins PW. Ketone photolysis in the presence of oxygen: A useful source of OH for flash photolysis kinetics experiments. INT J CHEM KINET 2008. [DOI: 10.1002/kin.20330] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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