51
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Orlando JJ, Tyndall GS. Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance. Chem Soc Rev 2012; 41:6294-317. [PMID: 22847633 DOI: 10.1039/c2cs35166h] [Citation(s) in RCA: 249] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- John J Orlando
- National Center for Atmospheric Research, Earth System Laboratory, Atmospheric Chemistry Division, Boulder, USA.
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52
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Stone D, Whalley LK, Heard DE. Tropospheric OH and HO2 radicals: field measurements and model comparisons. Chem Soc Rev 2012; 41:6348-404. [DOI: 10.1039/c2cs35140d] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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53
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Whalley L, Stone D, Heard D. New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Top Curr Chem (Cham) 2012; 339:55-95. [DOI: 10.1007/128_2012_359] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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54
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Vereecken L, Peeters J. A theoretical study of the OH-initiated gas-phase oxidation mechanism of β-pinene (C10H16): first generation products. Phys Chem Chem Phys 2012; 14:3802-15. [DOI: 10.1039/c2cp23711c] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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55
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Ziemann PJ, Atkinson R. Kinetics, products, and mechanisms of secondary organic aerosol formation. Chem Soc Rev 2012; 41:6582-605. [DOI: 10.1039/c2cs35122f] [Citation(s) in RCA: 423] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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56
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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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57
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Elrod MJ. Kinetics Study of the Aromatic Bicyclic Peroxy Radical + NO Reaction: Overall Rate Constant and Nitrate Product Yield Measurements. J Phys Chem A 2011; 115:8125-30. [DOI: 10.1021/jp204308f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew J. Elrod
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
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58
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Sharma A, Pushpa KK, Dhanya S, Naik PD, Bajaj PN. Rate constants for the gas-phase reactions of chlorine atoms with 1,4-cyclohexadiene and 1,5-cyclooctadiene at 298 K. INT J CHEM KINET 2011. [DOI: 10.1002/kin.20567] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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59
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Birdsall AW, Elrod MJ. Comprehensive NO-Dependent Study of the Products of the Oxidation of Atmospherically Relevant Aromatic Compounds. J Phys Chem A 2011; 115:5397-407. [DOI: 10.1021/jp2010327] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adam W. Birdsall
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
| | - Matthew J. Elrod
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio, 44074
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60
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Seakins PW, Blitz MA. Developments in Laboratory Studies of Gas-Phase Reactions for Atmospheric Chemistry with Applications to Isoprene Oxidation and Carbonyl Chemistry. Annu Rev Phys Chem 2011; 62:351-73. [PMID: 21219141 DOI: 10.1146/annurev-physchem-032210-102538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Laboratory studies of gas-phase chemical processes are a key tool in understanding the chemistry of our atmosphere and hence tackling issues such as climate change and air quality. Laboratory techniques have improved considerably with greater emphasis on product detection, allowing the measurement of site-specific rate coefficients. Radical chemistry lies at the heart of atmospheric chemistry. In this review we consider issues around radical generation and recycling from the oxidation of isoprene and from the chemical reactions and photolysis of carbonyl species. Isoprene is the most globally significant hydrocarbon, but uncertainties exist about its oxidation in unpolluted environments. Recent experiments and calculations that cast light on radical generation are reviewed. Carbonyl compounds are the dominant first-generation products from hydrocarbon oxidation. Chemical oxidation can recycle radicals, or photolysis can be a net radical source. Studies have demonstrated that high-resolution and temperature-dependent studies are important for some significant species.
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Affiliation(s)
| | - Mark A. Blitz
- School of Chemistry, University of Leeds, Leeds, LS2 9JT United Kingdom;
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61
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Theoretical approach of the mechanism of the reactions of chlorine atoms with aliphatic aldehydes. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2010.11.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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62
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Paulot F, Wunch D, Crounse JD, Toon GC, Millet DB, DeCarlo PF, Vigouroux C, Deutscher NM, González Abad G, Notholt J, Warneke T, Hannigan JW, Warneke C, de Gouw JA, Dunlea EJ, De Mazière M, Griffith DWT, Bernath P, Jimenez JL, Wennberg PO. Importance of secondary sources in the atmospheric budgets of formic and acetic acids. ATMOSPHERIC CHEMISTRY AND PHYSICS 2011; 11:1989-2013. [PMID: 33758586 PMCID: PMC7983864 DOI: 10.5194/acp-11-1989-2011] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ∼1200 and ∼1400Gmolyr-1, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.
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Affiliation(s)
- F. Paulot
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California, USA
| | - D. Wunch
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California, USA
| | - J. D. Crounse
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - G. C. Toon
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - D. B. Millet
- University of Minnesota, Department of Soil, Water and Climate, St. Paul, Minnesota, USA
| | - P. F. DeCarlo
- Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
| | - C. Vigouroux
- Belgian Institute for Space Aeronomy, Brussels, Belgium
| | - N. M. Deutscher
- School of Chemistry, University of Wollongong, Wollongong, Australia
| | | | - J. Notholt
- Institute of Environmental Physics, Bremen, Germany
| | - T. Warneke
- Institute of Environmental Physics, Bremen, Germany
| | - J. W. Hannigan
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - C. Warneke
- Earth System Research Laboratory, Chemical Sciences Division, NOAA, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
| | - J. A. de Gouw
- Earth System Research Laboratory, Chemical Sciences Division, NOAA, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
| | - E. J. Dunlea
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - M. De Mazière
- Belgian Institute for Space Aeronomy, Brussels, Belgium
| | - D. W. T. Griffith
- School of Chemistry, University of Wollongong, Wollongong, Australia
| | - P. Bernath
- Department of Chemistry, University of York, York, UK
| | - J. L. Jimenez
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - P. O. Wennberg
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California, USA
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63
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Navarro MA, Dusanter S, Hites RA, Stevens PS. Radical dependence of the yields of methacrolein and methyl vinyl ketone from the OH-initiated oxidation of isoprene under NO(x)-free conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:923-929. [PMID: 21175163 DOI: 10.1021/es103147w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Formation yields of methacrolein (MAC), methyl vinyl ketone (MVK), and 3-methyl furan (3MF) from the hydroxyl radical (OH) initiated oxidation of isoprene were investigated under NO(x)-free conditions (NO(x) = NO + NO(2)) at 50 °C and 1 atm in a quartz reaction chamber coupled to a mass spectrometer. Yields of the primary products were measured at various OH and hydroperoxy (HO(2)) radical concentrations and were found to decrease as the HO(2)-to-isoprene-based peroxy radical (ISORO(2)) concentration ratio increases. This is likely the result of a competition between ISORO(2) self- and cross-reactions that lead to the formation of the primary products, with reactions between these peroxy radicals and HO(2) which can lead to the formation of peroxides. Under conditions with HO(2)/ISORO(2) ratios close to 0.1, yields of MVK (15.5% ± 1.4%) and MAC (13.0% ± 1.2%) were higher than the yields of MVK (8.9% ± 0.9%) and MAC (10.9% ± 1.1%) measured under conditions with HO(2)/ISORO(2) ratios close to 1. This radical dependence of the yields was reproduced reasonably well by an explicit model of isoprene oxidation, suggesting that the model is able to reproduce the observed products yields under a realistic range of atmospheric HO(2)/ISORO(2) ratios.
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Affiliation(s)
- Maria A Navarro
- Center for Research in Environmental Science, School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
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64
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Birdsall AW, Andreoni JF, Elrod MJ. Investigation of the role of bicyclic peroxy radicals in the oxidation mechanism of toluene. J Phys Chem A 2011; 114:10655-63. [PMID: 20836528 DOI: 10.1021/jp105467e] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The products of the primary OH-initiated oxidation of toluene were investigated using the turbulent flow chemical ionization mass spectrometry technique under different oxygen, NO, and initial OH radical concentrations as well as a range of total pressures. The bicyclic peroxy radical intermediate, a key proposed intermediate species in the Master Chemical Mechanism (MCM) for the atmospheric oxidation of toluene, was detected for the first time. The toluene oxidation mechanism was shown to have a strong oxygen concentration dependence, presumably due to the central role of the bicyclic peroxy radical in determining the stable product distribution at atmospheric oxygen concentrations. The results also suggest a potential role for bicyclic peroxy radical + HO(2) reactions at high HO(2)/NO ratios. These reactions are postulated to be a source of the inconsistencies between environmental chamber results and predictions from the MCM.
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Affiliation(s)
- Adam W Birdsall
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, USA
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65
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da Silva G. Kinetics and Mechanism of the Glyoxal + HO2 Reaction: Conversion of HO2 to OH by Carbonyls. J Phys Chem A 2010; 115:291-7. [DOI: 10.1021/jp108358y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel da Silva
- Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville 3010, Victoria, Australia
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66
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Moortgat GK, Meyrahn H, Warneck P. Photolysis of Acetaldehyde in Air: CH4, CO and CO2Quantum Yields. Chemphyschem 2010; 11:3896-908. [DOI: 10.1002/cphc.201000757] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Geert K. Moortgat
- Max‐Planck‐Institut für Chemie, Division Atmospheric Chemistry, P.O. Box 3060, 55020 Mainz (Germany), Fax: (+49) 6131‐305436
| | | | - Peter Warneck
- Max‐Planck‐Institut für Chemie, P.O. Box 3060, 55020 Mainz (Germany)
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67
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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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68
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Roth E, Chakir A, Ferhati A. Study of a Benzoylperoxy Radical in the Gas Phase: Ultraviolet Spectrum and C6H5C(O)O2 + HO2 Reaction between 295 and 357 K. J Phys Chem A 2010; 114:10367-79. [DOI: 10.1021/jp1021467] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E. Roth
- Laboratoire GSMA, Université de Reims, Campus Moulin de la Housse, BP 1039, 51687 Reims cedex 02, France, CNRS, Laboratoire GSMA-UMR 6089, UFR Sciences, BP 1039, 51687 Reims cedex 02, France, and Laboratoire LCCE, Faculté des sciences, Université de Batna, rue Boukhlouf El Hadi 05000 Batna, Algeria
| | - A. Chakir
- Laboratoire GSMA, Université de Reims, Campus Moulin de la Housse, BP 1039, 51687 Reims cedex 02, France, CNRS, Laboratoire GSMA-UMR 6089, UFR Sciences, BP 1039, 51687 Reims cedex 02, France, and Laboratoire LCCE, Faculté des sciences, Université de Batna, rue Boukhlouf El Hadi 05000 Batna, Algeria
| | - A. Ferhati
- Laboratoire GSMA, Université de Reims, Campus Moulin de la Housse, BP 1039, 51687 Reims cedex 02, France, CNRS, Laboratoire GSMA-UMR 6089, UFR Sciences, BP 1039, 51687 Reims cedex 02, France, and Laboratoire LCCE, Faculté des sciences, Université de Batna, rue Boukhlouf El Hadi 05000 Batna, Algeria
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69
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Nguyen TL, Vereecken L, Peeters J. Theoretical Study of the HOCH2OO• + HO2
• Reaction: Detailed Molecular Mechanisms of the Three Reaction Channels. ACTA ACUST UNITED AC 2010. [DOI: 10.1524/zpch.2010.6142] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The HO2
• + HOCH2OO• reaction was theoretically investigated, using various high-level, single-reference Complete Basis Set methods including CBS-QB3, CBS-QCI/APNO and CBS-Q(MPW1B95) and a new multi-reference CI-PT2 approach. Three major product channels under atmospheric conditions were identified and their molecular mechanisms elucidated in great detail by Intrinsic Reaction Coordinate Analyses (IRC) at the B3LYP/6–311G(d,p) level: (i) Direct head-to-tail H-atom abstraction from the hydroperoxy radical by the alkylperoxy, occurring on the triplet Potential Energy Surface (PES) leading to HOCH2OOH + O2; (ii) A two-step rearrangement of the initial singlet HOCH2OOOOH tetroxide complex to form HC(O)OH + •OH + HO2
•; (iii) A multi-step rearrangement of the initial HOCH2OOOOH tetroxide to yield HC(O)OH + O2(1Δ) + H2O, about twice as fast as the former channel on the singlet-surface. The findings provide an explanation for the observed hydroxyl radical formation in this reaction (Jenkin et al., Phys. Chem. Chem. Phys. 9 (2007) 3149) and rationalize the high overall rate and its pronounced negative temperature dependence (Veyret et al., J. Phys. Chem.
93 (1989) 2368).
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Affiliation(s)
| | - Luc Vereecken
- University of Leuven, Department of Chemistry, Leuven, Belgien
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70
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Orlando JJ, Tyndall GS. The atmospheric oxidation of ethyl formate and ethyl acetate over a range of temperatures and oxygen partial pressures. INT J CHEM KINET 2010. [DOI: 10.1002/kin.20493] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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71
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da Silva G. Oxidation of Carboxylic Acids Regenerates Hydroxyl Radicals in the Unpolluted and Nighttime Troposphere. J Phys Chem A 2010; 114:6861-9. [DOI: 10.1021/jp101279p] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel da Silva
- Department of Chemical and Biomolecular Engineering, The University of Melbourne. Parkville 3010, Victoria, Australia
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72
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Kaiser EW, Pala IR, Wallington TJ. Kinetics and Mechanism of the Reaction of Methacrolein with Chlorine Atoms in 1−950 Torr of N2 or N2/O2 Diluent at 297 K. J Phys Chem A 2010; 114:6850-60. [DOI: 10.1021/jp103317c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- E. W. Kaiser
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, and System Analytics and Environmental Science Department, Research and Innovation Center, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053
| | - I. R. Pala
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, and System Analytics and Environmental Science Department, Research and Innovation Center, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053
| | - T. J. Wallington
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, and System Analytics and Environmental Science Department, Research and Innovation Center, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053
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73
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Takahashi K, Xing JH, Hurley MD, Wallington TJ. Kinetics and Mechanism of Chlorine-Atom-Initiated Oxidation of Allyl Alcohol, 3-Buten-2-ol, and 2-Methyl-3-buten-2-ol. J Phys Chem A 2010; 114:4224-31. [DOI: 10.1021/jp908104r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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74
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Paulot F, Crounse JD, Kjaergaard HG, Kürten A, St. Clair JM, Seinfeld JH, Wennberg PO. Response to Comment on “Unexpected Epoxide Formation in the Gas-Phase Photooxidation of Isoprene”. Science 2010; 327:644; author reply 644. [DOI: 10.1126/science.1181689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Claeys questions whether gaseous epoxydiol is formed from the oxidation of isoprene and whether it is relevant to the formation of isoprene-derived secondary organic aerosol (iSOA). We argue that the alternative mechanism she proposes for iSOA applies primarily to chamber studies with high isoprene and is not as important in the atmosphere, where isoprene concentrations are much lower.
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Affiliation(s)
- Fabien Paulot
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| | - John D. Crounse
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | | | - Andreas Kürten
- Institute for Atmospheric and Environmental Sciences, Goethe University, Frankfurt am Main, Germany
| | - Jason M. St. Clair
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| | - John H. Seinfeld
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Paul O. Wennberg
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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75
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Young CJ, Mabury SA. Atmospheric perfluorinated acid precursors: chemistry, occurrence, and impacts. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2010; 208:1-109. [PMID: 20811862 DOI: 10.1007/978-1-4419-6880-7_1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Perfluorocarboxylic acids (PFCAs) can be found from the hydrolysis of perfluoroacyl fluorides and chlorides, which can be produced in three separate ways in the atmosphere. Alternatively, PFCAs can be formed directly in the gas phase through reaction of perfluoroacyl peroxy radicals or perfluorinated aldehyde hydrates. All five mechanisms have been elucidated using smog chamber techniques. Yields of the PFCAs from this process vary from less than 10% to greater than 100%, depending on the mechanism. The formation of perfluorosulfonic acids in the atmosphere can also occur, though the mechanism has not been entirely elucidated. A large number of compounds have been confirmed as perfluorinated acid precursors, including CFC-replacement compounds, anesthetics, fluorotelomer compounds, and perfluorosulfonamides. Levels of some of these compounds have been measured in the atmosphere, but concentration for the majority have yet to be detected. It is clear that atmospheric oxidation of volatile precursors contributes to the overall burden of PFAs, though the extent to which this occurs is compound and environment dependent and is difficult to assess accurately.
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Affiliation(s)
- Cora J Young
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
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76
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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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77
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Sharma A, Pushpa KK, Dhanya S, Naik PD, Bajaj PN. Rate coefficients and products for gas-phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K. INT J CHEM KINET 2009. [DOI: 10.1002/kin.20467] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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78
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Jenkin ME, Hurley MD, Wallington TJ. Investigation of the Radical Product Channel of the CH3OCH2O2 + HO2 Reaction in the Gas Phase. J Phys Chem A 2009; 114:408-16. [DOI: 10.1021/jp908158w] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. E. Jenkin
- Atmospheric Chemistry Services, Okehampton, Devon, EX20 1FB, U.K., and Research and Advanced Engineering, Ford Motor Company, SRL-3083, PO Box 2053, Dearborn, Michigan 48121-2053
| | - M. D. Hurley
- Atmospheric Chemistry Services, Okehampton, Devon, EX20 1FB, U.K., and Research and Advanced Engineering, Ford Motor Company, SRL-3083, PO Box 2053, Dearborn, Michigan 48121-2053
| | - T. J. Wallington
- Atmospheric Chemistry Services, Okehampton, Devon, EX20 1FB, U.K., and Research and Advanced Engineering, Ford Motor Company, SRL-3083, PO Box 2053, Dearborn, Michigan 48121-2053
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79
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Nepomnyashchikh YV, Puchkov SV, Abdulova OV, Perkel’ AL. Kinetics and mechanism of the liquid-phase oxidation of n-carboxylic acids. KINETICS AND CATALYSIS 2009. [DOI: 10.1134/s0023158409050012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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80
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Hofzumahaus A, Rohrer F, Lu K, Bohn B, Brauers T, Chang CC, Fuchs H, Holland F, Kita K, Kondo Y, Li X, Lou S, Shao M, Zeng L, Wahner A, Zhang Y. Amplified Trace Gas Removal in the Troposphere. Science 2009; 324:1702-4. [DOI: 10.1126/science.1164566] [Citation(s) in RCA: 465] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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81
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Xing JH, Takahashi K, Hurley MD, Wallington TJ. Kinetics of the reaction of chlorine atoms with isoprene (2-methyl 1,3-butadiene, CH2C(CH3)CH CH2) at 297 ± 2 K. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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82
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Singh S, Hernandez S, Ibarra Y, Hasson AS. Kinetics and mechanism of the reactions ofn-butanal andn-pentanal with chlorine atoms. INT J CHEM KINET 2009. [DOI: 10.1002/kin.20383] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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83
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Hayes CJ, Merle JK, Hadad CM. The chemistry of reactive radical intermediates in combustion and the atmosphere. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0065-3160(08)00003-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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84
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Rasmussen CL, Jakobsen JG, Glarborg P. Experimental measurements and kinetic modeling of CH4/O2and CH4/C2H6/O2conversion at high pressure. INT J CHEM KINET 2008. [DOI: 10.1002/kin.20352] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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85
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Atmospheric oxidation capacity sustained by a tropical forest. Nature 2008; 452:737-40. [PMID: 18401407 DOI: 10.1038/nature06870] [Citation(s) in RCA: 244] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 02/22/2008] [Indexed: 11/09/2022]
Abstract
Terrestrial vegetation, especially tropical rain forest, releases vast quantities of volatile organic compounds (VOCs) to the atmosphere, which are removed by oxidation reactions and deposition of reaction products. The oxidation is mainly initiated by hydroxyl radicals (OH), primarily formed through the photodissociation of ozone. Previously it was thought that, in unpolluted air, biogenic VOCs deplete OH and reduce the atmospheric oxidation capacity. Conversely, in polluted air VOC oxidation leads to noxious oxidant build-up by the catalytic action of nitrogen oxides (NO(x) = NO + NO2). Here we report aircraft measurements of atmospheric trace gases performed over the pristine Amazon forest. Our data reveal unexpectedly high OH concentrations. We propose that natural VOC oxidation, notably of isoprene, recycles OH efficiently in low-NO(x) air through reactions of organic peroxy radicals. Computations with an atmospheric chemistry model and the results of laboratory experiments suggest that an OH recycling efficiency of 40-80 per cent in isoprene oxidation may be able to explain the high OH levels we observed in the field. Although further laboratory studies are necessary to explore the chemical mechanism responsible for OH recycling in more detail, our results demonstrate that the biosphere maintains a remarkable balance with the atmospheric environment.
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86
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Ren X, Olson JR, Crawford JH, Brune WH, Mao J, Long RB, Chen Z, Chen G, Avery MA, Sachse GW, Barrick JD, Diskin GS, Huey LG, Fried A, Cohen RC, Heikes B, Wennberg PO, Singh HB, Blake DR, Shetter RE. HOxchemistry during INTEX-A 2004: Observation, model calculation, and comparison with previous studies. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009166] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xinrong Ren
- Department of Meteorology; Pennsylvania State University; University Park Pennsylvania USA
| | - Jennifer R. Olson
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - James H. Crawford
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - William H. Brune
- Department of Meteorology; Pennsylvania State University; University Park Pennsylvania USA
| | - Jingqiu Mao
- Department of Meteorology; Pennsylvania State University; University Park Pennsylvania USA
| | - Robert B. Long
- Department of Meteorology; Pennsylvania State University; University Park Pennsylvania USA
| | - Zhong Chen
- Department of Meteorology; Pennsylvania State University; University Park Pennsylvania USA
| | - Gao Chen
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - Melody A. Avery
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - Glen W. Sachse
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - John D. Barrick
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - Glenn S. Diskin
- Science Directorate; NASA Langley Research Center; Hampton Virginia USA
| | - L. Greg Huey
- School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
| | - Alan Fried
- Earth Observing Laboratory; National Center for Atmospheric Research; Boulder Colorado USA
| | - Ronald C. Cohen
- Department of Chemistry and Department of Earth and Planetary Science; University of California; Berkeley California USA
| | - Brian Heikes
- Graduate School of Oceanography; University of Rhode Island; Narragansett Rhode Island USA
| | - Paul O. Wennberg
- Division of Engineering and Applied Sciences; California Institute of Technology; Pasadena California USA
| | | | - Donald R. Blake
- Department of Chemistry; University of California; Irvine California USA
| | - Richard E. Shetter
- National Suborbital Education and Research Center; University of North Dakota; Grand Forks North Dakota USA
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87
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Iwasaki E, Nakayama T, Matsumi Y, Takahashi K, Wallington TJ, Hurley MD, Kaiser EW. Kinetics and Mechanism of the Reaction of Chlorine Atoms with n-Pentanal. J Phys Chem A 2008; 112:1741-6. [DOI: 10.1021/jp077525z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
| | | | | | - K. Takahashi
- Kyoto University Pioneering Research Unit For Next Generation, Kyoto University Gokasho, Uji, Kyoto 611-0011, Japan
| | | | | | - E. W. Kaiser
- Department of Natural Sciences, 4901 Evergreen Road, University of MichiganDearborn, Dearborn, Michigan 48128
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88
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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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89
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Jenkin ME, Hurley MD, Wallington TJ. Investigation of the radical product channel of the CH3C(O)CH2O2 + HO2 reaction in the gas phase. Phys Chem Chem Phys 2008; 10:4274-80. [DOI: 10.1039/b802898b] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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90
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Sharp EN, Rupper P, Miller TA. The structure and spectra of organic peroxy radicals. Phys Chem Chem Phys 2008; 10:3955-81. [DOI: 10.1039/b800954f] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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91
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Hou H, Wang B. A systematic computational study on the reactions of HO2 with RO2: The HO2 + CH3O2(CD3O2) and HO2 + CH2FO2 reactions. J Phys Chem A 2007; 109:451-60. [PMID: 16833365 DOI: 10.1021/jp046329e] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A systematic theoretical study of the reactions of HO2 with RO2 has been carried out. The major concern of the present work is to gain insight into the reaction mechanism and then to explain experimental observations and to predict new product channels for this class of reactions of importance in the atmosphere. In this paper, the reaction mechanisms for two reactions, namely, HO2 + CH3O2 and HO2 + CH2FO2, are reported. Both singlet and triplet potential energy surfaces are investigated. The complexity of the present system makes it impossible to use a single ab initio method to map out all the reaction paths. Various ab initio methods including MP2, CISD, QCISD(T), CCSD(T), CASSCF, and density function theory (B3LYP) have been employed with the basis sets ranging from 6-31G(d) to an extrapolated complete basis set (CBS) limit. It has been established that the CCSD(T)/cc-pVDZ//B3LYP/6-311G(d,p) scheme represents the most feasible method for our systematic study. For the HO2 + CH3O2 reaction, the production of CH3OOH is determined to be the dominant channel. For the HO2 + CH2FO2 reaction, both CH2FOOH and CHFO are major products, whereas the formation of CHFO is dominant in the overall reaction. The computational findings give a fair explanation for the experimental observation of the products.
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Affiliation(s)
- Hua Hou
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People's Republic of China
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92
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Waterland RL, Dobbs KD. Atmospheric Chemistry of Linear Perfluorinated Aldehydes: Dissociation Kinetics of CnF2n+1CO Radicals. J Phys Chem A 2007; 111:2555-62. [PMID: 17388359 DOI: 10.1021/jp067587+] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Linear perfluorinated aldehydes (PFALs, CnF2n+1CHO) are important intermediate species in the atmospheric oxidation pathway of many polyfluorinated compounds. PFALs can be further oxidized in the gas phase to give perfluorinated carboxylic acids (PFCAs, CnF2n+1C(O)OH, n = 6, 12) which have been detected in animal tissues and at low parts per billion levels in human blood sera. In this paper, we report ab initio quantum chemistry calculations of the decarbonylation kinetics of CnF2n+1CO radicals. Our results show that CnF2n+1CO radicals have a strong tendency to decompose to give CnF2n+1 and CO under atmospheric conditions: the Arrhenius activation energies for decarbonylation of CF3CO, C2F5CO, and C3F7CO obtained using PMP4/6-311++G(2d,p) are 8.8, 6.6, and 5.8 kcal/mol, respectively, each of which is about 5 kcal/mol lower than the barrier for the corresponding nonfluorinated radicals. The lowering of the barrier for decarbonylation of CnF2n+1CO relative to that of CnH2n+1CO is well explained by electron withdrawal by F atoms that serve to weaken the critical C-CO bond. These results have important implications for the atmospheric fate of PFALs and the atmospheric pathways to PFCAs. The main effect of decarbonylation of CnF2n+1CO is to decrease the molar yield of CnF2n+1C(O)OH; if 100% of the CnF2n+1CO decompose, the yield of CnF2n+1C(O)OH must be zero. There is considerable scope for additional experimental and theoretical studies.
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Affiliation(s)
- Robert L Waterland
- DuPont Central Research & Development, Experimental Station, P. O. Box 80320, Wilmington, Delaware 19880-0320, USA.
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93
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Jenkin ME, Hurley MD, Wallington TJ. Investigation of the radical product channel of the CH3C(O)O2 + HO2 reaction in the gas phase. Phys Chem Chem Phys 2007; 9:3149-62. [PMID: 17612738 DOI: 10.1039/b702757e] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of CH(3)C(O)O(2) with HO(2) has been investigated at 296 K and 700 Torr using long path FTIR spectroscopy, during photolysis of Cl(2)/CH(3)CHO/CH(3)OH/air mixtures. The branching ratio for the reaction channel forming CH(3)C(O)O, OH and O(2) (reaction ) has been determined from experiments in which OH radicals were scavenged by addition of benzene to the system, with subsequent formation of phenol used as the primary diagnostic for OH radical formation. The dependence of the phenol yield on benzene concentration was found to be consistent with its formation from the OH-initiated oxidation of benzene, thereby confirming the presence of OH radicals in the system. The dependence of the phenol yield on the initial peroxy radical precursor reagent concentration ratio, [CH(3)OH](0)/[CH(3)CHO](0), is consistent with OH formation resulting mainly from the reaction of CH(3)C(O)O(2) with HO(2) in the early stages of the experiments, such that the limiting yield of phenol at high benzene concentrations is well-correlated with that of CH(3)C(O)OOH, a well-established product of the CH(3)C(O)O(2) + HO(2) reaction (via channel (3a)). However, a delayed source of phenol was also identified, which is attributed mainly to an analogous OH-forming channel of the reaction of HO(2) with HOCH(2)O(2) (reaction ), formed from the reaction of HO(2) with product HCHO. This was investigated in additional series of experiments in which Cl(2)/CH(3)OH/benzene/air and Cl(2)/HCHO/benzene/air mixtures were photolysed. The various reaction systems were fully characterised by simulations using a detailed chemical mechanism. This allowed the following branching ratios to be determined: CH(3)C(O)O(2) + HO(2)--> CH(3)C(O)OOH + O(2), k(3a)/k(3) = 0.38 +/- 0.13; --> CH(3)C(O)OH + O(3), k(3b)/k(3) = 0.12 +/- 0.04; --> CH(3)C(O)O + OH + O(2), k(3c)/k(3) = 0.43 +/- 0.10: HOCH(2)O(2) + HO(2)--> HCOOH + H(2)O + O(2), k(17b)/k(17) = 0.30 +/- 0.06; --> HOCH(2)O + OH + O(2), k(17c)/k(17) = 0.20 +/- 0.05. The results therefore provide strong evidence for significant participation of the radical-forming channels of these reactions, with the branching ratio for the title reaction being in good agreement with the value reported in one previous study. As part of this work, the kinetics of the reaction of Cl atoms with phenol (reaction (14)) have also been investigated. The rate coefficient was determined relative to the rate coefficient for the reaction of Cl with CH(3)OH, during the photolysis of mixtures of Cl(2), phenol and CH(3)OH, in either N(2) or air at 296 K and 760 Torr. A value of k(14) = (1.92 +/- 0.17) x 10(-10) cm(3) molecule(-1) s(-1) was determined from the experiments in N(2), in agreement with the literature. In air, the apparent rate coefficient was about a factor of two lower, which is interpreted in terms of regeneration of phenol from the product phenoxy radical, C(6)H(5)O, possibly via its reaction with HO(2).
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Affiliation(s)
- M E Jenkin
- Centre for Environmental Policy, Imperial College London, Silwood Park, Ascot, Berkshire, UK.
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94
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Teresa Raventós-Duran M, Percival CJ, McGillen MR, Hamer PD, Shallcross DE. Kinetics and branching ratio studies of the reaction of C2H5O2 + HO2 using chemical ionisation mass spectrometry. Phys Chem Chem Phys 2007; 9:4338-48. [PMID: 17687481 DOI: 10.1039/b703038j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The overall rate coefficient for the reaction of C(2)H(5)O(2) with HO(2) was determined using a turbulent flow chemical ionization mass spectrometer (TF-CIMS) system over the pressure range of 75 to 200 Torr and temperatures between 195 and 298 K. The temperature dependence of the overall rate coefficient for the reaction between C(2)H(5)O(2) and HO(2) was fitted using the following Arrhenius expression: k(T) = (2.08) x 10(-13) exp [(864 +/- 79)/T] cm(-3) molecule(-1) s(-1). The upper limits for the branching ratios for reactive channels leading to O(3) and OH production were quantified for the first time. A tropospheric model has been used to assess the impact of the experimental error of the rate coefficients determined in this study on predicted concentrations of a number of key species, including O(3), OH, HO(2), NO and NO(2). In all cases it is found that the propagated error is very small and will not in itself be a major cause of uncertainty in modelled concentrations. However, at low temperatures, where there is a wide discrepancy between existing kinetic studies, modelling using the range of kinetic data in the literature shows a small but significant variation for [C(2)H(5)O(2)], [C(2)H(5)OOH], [NO(x)] and the HO(2) : OH ratio. Furthermore, a structure-activity relationship (SAR) was developed to rationalise the reactivity of the reaction between RO(2) and HO(2).
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Affiliation(s)
- M Teresa Raventós-Duran
- The School of Earth, Atmospheric and Environmental Science, The University of Manchester, Sackville Street, Manchester, UK
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95
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Raventós-Duran MT, McGillen M, Percival CJ, Hamer PD, Shallcross DE. Kinetics of the CH3O2 + HO2 reaction: A temperature and pressure dependence study using chemical ionization mass spectrometry. INT J CHEM KINET 2007. [DOI: 10.1002/kin.20269] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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96
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Hurley MD, Ball JC, Wallington TJ, Sulbaek Andersen MP, Nielsen OJ, Ellis DA, Martin JW, Mabury SA. Atmospheric Chemistry of n-CxF2x+1CHO (x = 1, 2, 3, 4): Fate of n-CxF2x+1C(O) Radicals. J Phys Chem A 2006; 110:12443-7. [PMID: 17091948 DOI: 10.1021/jp064029m] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Smog chamber/FTIR techniques were used to study the atmospheric fate of n-C(x)F(2)(x)(+1)C(O) (x = 1, 2, 3, 4) radicals in 700 Torr O(2)/N(2) diluent at 298 +/- 3 K. A competition is observed between reaction with O(2) to form n-C(x)()F(2)(x)()(+1)C(O)O(2) radicals and decomposition to form n-C(x)F(2)(x)(+1) radicals and CO. In 700 Torr O(2)/N(2) diluent at 298 +/- 3 K, the rate constant ratio, k(n-C(x)F(2)(x)(+1)C(O) + O(2) --> n-C(x)F(2)(x)(+1)C(O)O(2))/k(n-C(x)F(2)(x)(+1)C(O) --> n-C(x)F(2)(x)(+1) + CO) = (1.30 +/- 0.05) x 10(-17), (1.90 +/- 0.17) x 10(-19), (5.04 +/- 0.40) x 10(-20), and (2.67 +/- 0.42) x 10(-20) cm(3) molecule(-1) for x = 1, 2, 3, 4, respectively. In one atmosphere of air at 298 K, reaction with O(2) accounts for 99%, 50%, 21%, and 12% of the loss of n-C(x)F(2)(x)(+1)C(O) radicals for x = 1, 2, 3, 4, respectively. Results are discussed with respect to the atmospheric chemistry of n-C(x)F(2)(x)(+1)C(O) radicals and their possible role in contributing to the formation of perfluorocarboxylic acids in the environment.
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Affiliation(s)
- M D Hurley
- Ford Motor Company, P.O. Box 2053, Dearborn, Michigan 48121-2053, USA.
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97
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Le Crâne JP, Rayez MT, Rayez JC, Villenave E. A reinvestigation of the kinetics and the mechanism of the CH3C(O)O2 + HO2 reaction using both experimental and theoretical approaches. Phys Chem Chem Phys 2006; 8:2163-71. [PMID: 16751874 DOI: 10.1039/b518321a] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The kinetics and the mechanism of the reaction CH(3)C(O)O(2)+ HO(2) were reinvestigated at room temperature using two complementary approaches: one experimental, using flash photolysis/UV absorption technique and one theoretical, with quantum chemistry calculations performed using the density functional theory (DFT) method with the three-parameter hybrid functional B3LYP associated with the 6-31G(d,p) basis set. According to a recent paper reported by Hasson et al., [J. Phys. Chem., 2004, 108, 5979-5989] this reaction may proceed by three different channels: CH(3)C(O)O(2)+ HO(2)--> CH(3)C(O)OOH + O(2) (1a); CH(3)C(O)O(2)+ HO(2)--> CH(3)C(O)OH + O(3) (1b); CH(3)C(O)O(2)+ HO(2)--> CH(3)C(O)O + OH + O(2) (1c). In experiments, CH(3)C(O)O(2) and HO(2) radicals were generated using Cl-initiated oxidation of acetaldehyde and methanol, respectively, in the presence of oxygen. The addition of amounts of benzene in the system, forming hydroxycyclohexadienyl radicals in the presence of OH, allowed us to answer that channel (1c) is <10%. The rate constant k(1) of reaction (1) has been finally measured at (1.50 +/- 0.08) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K, after having considered the combination of all the possible values for the branching ratios k(1a)/k(1,)k(1b)/k(1,)k(1c)/k(1) and has been compared to previous measurements. The branching ratio k(1b)/k(1), determined by measuring ozone in situ, was found to be equal to (20 +/- 1)%, a value consistent with the previous values reported in the literature. DFT calculations show that channel (1c) is also of minor importance: it was deduced unambiguously that the formation of CH(3)C(O)OOH + O(2) (X (3)Sigma(-)(g)) is the dominant product channel, followed by the second channel (1b) leading to CH(3)C(O)OH and singlet O(3) and, much less importantly, channel (1c) which corresponds to OH formation. These conclusions give a reliable explanation of the experimental observations of this work. In conclusion, the present study demonstrates that the CH(3)C(O)O(2)+ HO(2) is still predominantly a radical chain termination reaction in the tropospheric ozone chain formation processes.
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Affiliation(s)
- Jean-Paul Le Crâne
- Laboratoire de Physico-Chimie Moléculaire, CNRS UMR 5803, Université Bordeaux I, 33405, Talence Cedex, France.
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98
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Hou H, Li J, Song X, Wang B. A systematic computational study of the reactions of HO2 with RO2: the HO2 + C2H5O2 reaction. J Phys Chem A 2006; 109:11206-12. [PMID: 16331904 DOI: 10.1021/jp0550098] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of HO2 with C2H5O2 has been studied using the density functional theory (B3LYP) and the coupled-cluster theory [CCSD(T)]. The reaction proceeds on the triplet potential energy surface via hydrogen abstraction to form ethyl hydroperoxide and oxygen. On the singlet potential energy surface, the addition-elimination mechanism is revealed. Variational transition state theory is used to calculate the temperature-dependent rate constants in the range 200-1000 K. At low temperatures (e.g., below 300 K), the reaction takes place predominantly on the triplet surface. The calculated low-temperature rate constants are in good agreement with the experimental data. As the temperature increases, the singlet reaction mechanism plays more and more important role, with the formation of OH radical predominantly. The isotope effect of the reaction (DO2 + C2D5O2 vs HO2 + C2H5O2) is negligible. In addition, the triplet abstraction energetic routes for the reactions of HO2 with 11 alkylperoxy radicals (CnHmO2) are studied. It is shown that the room-temperature rate constants have good linear correlation with the activation energies for the hydrogen abstraction.
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Affiliation(s)
- Hua Hou
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, People's Republic of China
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Palmer PI, Abbot DS, Fu TM, Jacob DJ, Chance K, Kurosu TP, Guenther A, Wiedinmyer C, Stanton JC, Pilling MJ, Pressley SN, Lamb B, Sumner AL. Quantifying the seasonal and interannual variability of North American isoprene emissions using satellite observations of the formaldehyde column. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006689] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
100
|
Devolder P, Dusanter S, Lemoine B, Fittschen C. About the co-product of the OH radical in the reaction of acetyl with O2 below atmospheric pressure. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.09.114] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|