101
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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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102
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Liang YN, Li J, Wang QD, Wang F, Li XY. Computational study of the reaction mechanism of the methylperoxy self-reaction. J Phys Chem A 2011; 115:13534-41. [PMID: 22004094 DOI: 10.1021/jp2048508] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To provide insight on the reaction mechanism of the methyperoxy (CH(3)O(2)•) self-reaction, stationary points on both the spin-singlet and the spin-triplet potential energy surfaces of 2(CH(3)O(2)•) have been searched at the B3LYP/6-311++G(2df,2p) level. The relative energies, enthalpies, and free energies of these stationary points are calculated using CCSD(T)/cc-pVTZ. Our theoretical results indicate that reactions on a spin-triplet potential energy surface are kinetically unfavorable due to high free energy barriers, while they are more complicated on the spin-singlet surface. CH(3)OOCH(3) + O(2)(1) can be produced directly from 2(CH(3)O(2)•), while in other channels, three spin-singlet chain-structure intermediates are first formed and subsequently dissociated to produce different products. Besides the dominant channels producing 2CH(3)O• + O(2) and CH(3)OH + CH(2)O + O(2) as determined before, the channels leading to CH(3)OOOH + CH(2)O and CH(3)O• + CH(2)O + HO(2)• are also energetically favorable in the self-reaction of CH(3)O(2)• especially at low temperature according to our results.
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Affiliation(s)
- Yan-Ni Liang
- College of Chemistry, Sichuan University, Chengdu, People's Republic of China
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103
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Grieman FJ, Noell AC, Davis-Van Atta C, Okumura M, Sander SP. Determination of Equilibrium Constants for the Reaction between Acetone and HO2 Using Infrared Kinetic Spectroscopy. J Phys Chem A 2011; 115:10527-38. [DOI: 10.1021/jp205347s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fred J. Grieman
- Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | | | - Casey Davis-Van Atta
- Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
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104
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Lee KM, Sung EM. Computational Investigation of Isomeric and Conformeric Structures of Methyl Fluoroperoxide and Fluoromethyl Fluoroperoxides. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2011. [DOI: 10.5012/jkcs.2011.55.3.405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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105
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Peroxy ethoxyformyl nitrate, CH3CH2OC(O)OONO2. Spectroscopic and thermal characterization. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.04.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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106
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Liu CL, Smith JD, Che DL, Ahmed M, Leone SR, Wilson KR. The direct observation of secondary radical chain chemistry in the heterogeneous reaction of chlorine atoms with submicron squalane droplets. Phys Chem Chem Phys 2011; 13:8993-9007. [DOI: 10.1039/c1cp20236g] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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107
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Zhang T, Wang W, Zhang P, Lü J, Zhang Y. Water-catalyzed gas-phase hydrogen abstraction reactions of CH3O2 and HO2 with HO2: a computational investigation. Phys Chem Chem Phys 2011; 13:20794-805. [DOI: 10.1039/c1cp21563a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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108
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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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109
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Rio C, Flaud P, Loison J, Villenave E. Experimental Revaluation of the Importance of the Abstraction Channel in the Reactions of Monoterpenes with OH Radicals. Chemphyschem 2010; 11:3962-70. [DOI: 10.1002/cphc.201000518] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Caroline Rio
- Université de Bordeaux, Institut des Sciences Moléculaires, 351 Cours de la Libération, 33405 Talence Cedex (France), Fax.: (+33) 5‐4000‐6645
- CNRS UMR 5255, 351 Cours de la Libération, 33405 Talence Cedex (France)
| | - Pierre‐Marie Flaud
- Université de Bordeaux, Institut des Sciences Moléculaires, 351 Cours de la Libération, 33405 Talence Cedex (France), Fax.: (+33) 5‐4000‐6645
- CNRS UMR 5255, 351 Cours de la Libération, 33405 Talence Cedex (France)
| | - Jean‐Christophe Loison
- Université de Bordeaux, Institut des Sciences Moléculaires, 351 Cours de la Libération, 33405 Talence Cedex (France), Fax.: (+33) 5‐4000‐6645
- CNRS UMR 5255, 351 Cours de la Libération, 33405 Talence Cedex (France)
| | - Eric Villenave
- Université de Bordeaux, Institut des Sciences Moléculaires, 351 Cours de la Libération, 33405 Talence Cedex (France), Fax.: (+33) 5‐4000‐6645
- CNRS UMR 5255, 351 Cours de la Libération, 33405 Talence Cedex (France)
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110
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Allen D, Pickering K, Duncan B, Damon M. Impact of lightning NO emissions on North American photochemistry as determined using the Global Modeling Initiative (GMI) model. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014062] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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111
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Sulbaek Andersen MP, Andersen VF, Nielsen OJ, Sander SP, Wallington TJ. Atmospheric Chemistry of HCF
2
O(CF
2
CF
2
O)
x
CF
2
H (
x
=2–4): Kinetics and Mechanisms of the Chlorine‐Atom‐Initiated Oxidation. Chemphyschem 2010; 11:4035-41. [DOI: 10.1002/cphc.201000438] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mads P. Sulbaek Andersen
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive,Stop 183‐901, Pasadena, CA 91109 (USA), Fax: (+1) 818‐393‐5019
| | - Vibeke F. Andersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK‐2100 Copenhagen (Denmark)
| | - Ole J. Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK‐2100 Copenhagen (Denmark)
| | - Stanley P. Sander
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive,Stop 183‐901, Pasadena, CA 91109 (USA), Fax: (+1) 818‐393‐5019
| | - Timothy J. Wallington
- Systems Analytics and Environmental Sciences Department, Ford Motor Company,Drop RIC‐2122, Dearborn, Michigan 48121‐2053 (USA), Fax: (+1) 313‐323‐1129
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112
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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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113
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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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114
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Glowacki DR, Pilling MJ. Unimolecular Reactions of Peroxy Radicals in Atmospheric Chemistry and Combustion. Chemphyschem 2010; 11:3836-43. [DOI: 10.1002/cphc.201000469] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- David R. Glowacki
- Centre for Computational Chemistry, University of Bristol, Bristol BS8 1TS (UK)
| | - Michael J. Pilling
- School of Chemistry, University of Leeds, Leeds, LS2 9JT (UK), Fax: (+44) 113‐3436401
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115
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116
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Sulbaek Andersen MP, Hurley MD, Andersen VF, Nielsen OJ, Wallington TJ. CHF2OCHF2 (HFE-134): IR Spectrum and Kinetics and Products of the Chlorine-Atom-Initiated Oxidation. J Phys Chem A 2010; 114:4963-7. [DOI: 10.1021/jp101507f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mads P. Sulbaek Andersen
- Department of Chemistry, 572 Rowland Hall, University of California Irvine, Irvine, California 92697-2025, System Analytics and Environmental Sciences Department, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Michael D. Hurley
- Department of Chemistry, 572 Rowland Hall, University of California Irvine, Irvine, California 92697-2025, System Analytics and Environmental Sciences Department, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Vibeke F. Andersen
- Department of Chemistry, 572 Rowland Hall, University of California Irvine, Irvine, California 92697-2025, System Analytics and Environmental Sciences Department, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Ole J. Nielsen
- Department of Chemistry, 572 Rowland Hall, University of California Irvine, Irvine, California 92697-2025, System Analytics and Environmental Sciences Department, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Timothy J. Wallington
- Department of Chemistry, 572 Rowland Hall, University of California Irvine, Irvine, California 92697-2025, System Analytics and Environmental Sciences Department, Ford Motor Company, Mail Drop RIC-2122, Dearborn, Michigan 48121-2053, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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117
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Just GMP, Rupper P, Miller TA, Meerts WL. High-resolution cavity ringdown spectroscopy of the jet-cooled propyl peroxy radical C3H7O2. Phys Chem Chem Phys 2010; 12:4773-82. [DOI: 10.1039/b924323b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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118
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Chacon-Madrid HJ, Presto AA, Donahue NM. Functionalization vs. fragmentation: n-aldehyde oxidation mechanisms and secondary organic aerosol formation. Phys Chem Chem Phys 2010; 12:13975-82. [DOI: 10.1039/c0cp00200c] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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119
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Kirk BB, Harman DG, Blanksby SJ. Direct Observation of the Gas Phase Reaction of the Cyclohexyl Radical with Dioxygen Using a Distonic Radical Ion Approach. J Phys Chem A 2009; 114:1446-56. [DOI: 10.1021/jp9073398] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Benjamin B. Kirk
- School of Chemistry, University of Wollongong, NSW, Australia 2522
| | - David. G. Harman
- School of Chemistry, University of Wollongong, NSW, Australia 2522
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120
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Just GMP, Rupper P, Miller TA, Meerts WL. High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2. J Chem Phys 2009; 131:184303. [PMID: 19916600 DOI: 10.1063/1.3262612] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have recorded high resolution, partially rotationally resolved, jet-cooled cavity ringdown spectra of the origin band of the A-X electronic transition of both the G and T conformers of the perproteo and perdeutero isotopologues of the ethyl peroxy radical, C(2)H(5)O(2). This transition, located in the near infrared, was studied using a narrow band laser source (< or approximately 250 MHz) and a supersonic slit-jet expansion coupled with an electric discharge allowing us to obtain rotational temperatures of about 15 K. All four spectra have been successfully simulated using an evolutionary algorithm approach with a Hamiltonian including rotational and spin-rotational terms. Excellent agreement with the experimental spectra was obtained by fitting seven molecular parameters in each ground and the first excited electronic states as well as the band origin of the electronic transition. This analysis unambiguously confirms the assignment of the lower frequency origin band to the G conformer and the higher frequency one to the T conformer.
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Affiliation(s)
- Gabriel M P Just
- Department of Chemistry, Laser Spectroscopy Facility, The Ohio State University, 120 W. 18th Avenue, Columbus, Ohio 43210, USA
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121
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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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122
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Kosmas AM, Salta Z, Lesar A. Effect of halogenation on the mechanism of the atmospheric reactions between methylperoxy radicals and NO. A computational study. J Phys Chem A 2009; 113:3545-54. [PMID: 19301893 DOI: 10.1021/jp808895a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mechanism of the reactions between the halogenated methylperoxy radicals, CHX(2)O(2) (X = F, Cl), and NO is investigated by using ab initio and density functional quantum mechanical methods. Comparison is made with the mechanism of the CH(3)O(2) + NO reaction. The most important energy minima in the potential energy surface are found to be the two conformers of the halogenated methyl peroxynitrite association adducts, CHX(2)OONOcp and CHX(2)OONOtp, and the halogenated methyl nitrates, CHX(2)ONO(2). The latter are suggested to be formed through the one-step isomerization of the peroxynitrite adduct and may lead upon decomposition to carbonylated species, CX(2)O + HONO and CHXO + XNO(2). The ambiguous issue of the unimolecular peroxynitrite to nitrate isomerization is reconsidered, and the possibility of a triplet transition state involvement in the ROONOtp <--> RONO(2) rearrangement is examined. The overall calculations and the detailed correlation with the methyl system show the significant effect of the halogenation on the lowering of the entrance potential energy well which corresponds to the formation of the peroxynitrites. The increased attractive character of the potential energy surface found upon halogenation combined with the increased exothermicity of the CHX(2)O(2) + NO --> CHX(2)O + NO(2) reaction are suggested to be the important factors contributing to the enhanced reactivity of the halogenated reactions relative to CH(3)O(2) + NO. The calculated heat of formation values indicate the large stabilization of the fluorinated derivatives.
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Affiliation(s)
- Agnie M Kosmas
- Division of Physical Chemistry, Department of Chemistry, University of Ioannina, Greece 45110
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123
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Kim SW, Heckel A, Frost GJ, Richter A, Gleason J, Burrows JP, McKeen S, Hsie EY, Granier C, Trainer M. NO2columns in the western United States observed from space and simulated by a regional chemistry model and their implications for NOxemissions. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011343] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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124
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Rinsland CP, Mahieu E, Chiou L, Herbin H. First ground-based infrared solar absorption measurements of free tropospheric methanol (CH3OH): Multidecade infrared time series from Kitt Peak (31.9°N 111.6°W): Trend, seasonal cycle, and comparison with previous measurements. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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125
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Somnitz H, Ufer T, Zellner R. Acetone photolysis at 248 nm revisited: pressure dependence of the CO and CO2 quantum yields. Phys Chem Chem Phys 2009; 11:8522-31. [DOI: 10.1039/b906751e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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126
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Wallington TJ, Hurley MD, Javadi MS, Nielsen OJ. Kinetics and products of chlorine atom initiated oxidation of HCF2OCF2OCF2CF2OCF2H and HCF2O(CF2O)n-(CF2CF2O)mCF2H. INT J CHEM KINET 2008. [DOI: 10.1002/kin.20349] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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127
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Manetti MD, Malanca FE, Argüello GA. Thermal decomposition of trifluoromethoxycarbonyl peroxy nitrate, CF3OC(O)O2NO2. INT J CHEM KINET 2008. [DOI: 10.1002/kin.20355] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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128
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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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129
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Kosmas AM, Lesar A. Computational study of the perhalogenated methyl nitrates CX3ONO2, CXxY3−xONO2(X, Y = F, Cl). Mol Phys 2008. [DOI: 10.1080/00268970802077843] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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130
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Stimac PJ, Barker JR. Non-RRKM Dynamics in the CH3O2 + NO Reaction System. J Phys Chem A 2008; 112:2553-62. [DOI: 10.1021/jp710016n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Philip J. Stimac
- Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143
| | - John R. Barker
- Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143
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131
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Vlasenko A, George IJ, Abbatt JPD. Formation of volatile organic compounds in the heterogeneous oxidation of condensed-phase organic films by gas-phase OH. J Phys Chem A 2008; 112:1552-60. [PMID: 18225872 DOI: 10.1021/jp0772979] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The yield of volatile organic compounds (VOCs) from the heterogeneous oxidation of condensed-phase organic and hydrocarbon soot films by gas-phase OH has been studied in a coated-wall flow tube at room temperature. Simultaneously, OH concentrations are measured using a chemical-ionization mass spectrometer (CIMS) operated in negative ion mode and VOCs are measured using a commercial proton-transfer-reaction mass spectrometer (PTR-MS). It is observed that a variety of aldehydes/carbonyls and carboxylic acids are formed. Specifically, detailed experiments were conducted with stearic acid, where products are observed that contain as many as 13 carbon atoms with the average carbon number of the products between 3 and 5. The yield of VOCs, relative to the loss of OH radicals, is strongly dependent on the partial pressure of O2 in the carrier gas, ranging from 0.08 +/- 0.03 in a nominally pure He carrier gas to 0.34 +/- 0.14 in 6 Torr of pure O2. Yields from other organics are somewhat lower than those from stearic acid, ranging in conditions of pure O2 from 0.10 +/- 0.04 for BES (bis(ethylhexyl)sebacate), to 0.03 +/- 0.01 for n-hexane soot, to 0.01 +/- 0.005 for pyrene. Under atmospheric conditions, OH oxidation of select organics may be an efficient source of small VOCs. In particular, formic acid is formed in significant yield from all the surfaces.
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Affiliation(s)
- Alexander Vlasenko
- Department of Chemistry and Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
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132
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Pfister GG, Hess PG, Emmons LK, Rasch PJ, Vitt FM. Impact of the summer 2004 Alaska fires on top of the atmosphere clear-sky radiation fluxes. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd008797] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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133
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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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134
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Huang DR, Chu LK, Lee YP. Infrared absorption of gaseous CH3OO detected with a step-scan Fourier-transform spectrometer. J Chem Phys 2007; 127:234318. [DOI: 10.1063/1.2807241] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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135
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Wu S, Dupré P, Rupper P, Miller TA. The vibrationless Ã←X̃ transition of the jet-cooled deuterated methyl peroxy radical CD3O2 by cavity ringdown spectroscopy. J Chem Phys 2007; 127:224305. [DOI: 10.1063/1.2802202] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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136
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da Silva G, Bozzelli JW. Thermochemistry, Bond Energies, and Internal Rotor Potentials of Dimethyl Tetraoxide. J Phys Chem A 2007; 111:12026-36. [DOI: 10.1021/jp075144f] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel da Silva
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, and Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia
| | - Joseph W. Bozzelli
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, and Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia
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137
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Javadi MS, Nielsen OJ, Wallington TJ, Hurley MD, Owens JG. Atmospheric chemistry of 2-ethoxy-3,3,4,4,5-pentafluorotetrahydro-2,5-bis[1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl]-furan: kinetics, mechanisms, and products of Cl atom and OH radical initiated oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:7389-7395. [PMID: 18044516 DOI: 10.1021/es071175c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Smog chamber/FTIR techniques were used to study the atmospheric chemistry of the title compound which we refer to as RfOC2H5. Rate constants of k(Cl + RfOC2H5) = (2.70 +/- 0.36) x 10(-12), k(OH + RfOC2H5) = (5.93 +/- 0.85) x 10(-14), and k(Cl + RfOCHO) = (1.34 +/- 0.20) x 10(-14) cm3 molecule(-1') s(-1) were measured in 700 Torr of N2, or air, diluent at 294 +/- 1 K. From the value of k(OH + RfOC2H5) the atmospheric lifetime of RfOC2H5 was estimated to be 1 year. Two competing loss mechanisms for RfOCH(O*)CH3 radicals were identified in 700 Torr of N2/O2 diluent at 294 +/- 1 K; decomposition via C-C bond scission giving a formate (RfOCHO), or reaction with 02 giving an acetate (RfOC(O)CH3). In 700 Torr of N2/O2 diluent at 294 +/- 1 K the rate constant ratio k(O2)/k(diss) = (1.26 +/- 0.74) x 10(-19) cm3 molecule(-1). The OH radical initiated atmospheric oxidation of RfOC2H5 gives Rf0CHO and RfOC(O)CH3 as major products. RfOC2H5 has a global warming potential of approximately 55 for a 100 year horizon. The results are discussed with respect to the atmospheric chemistry and environmental impact of RfOC2H5.
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Affiliation(s)
- M S Javadi
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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138
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Lesar A, Salta Z, Kovačič S, Kosmas AM. Theoretical characterization of halogenated methylperoxy nitrites CX Y3−OONO (X, Y = H, F, Cl). Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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139
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Chung CY, Cheng CW, Lee YP, Liao HY, Sharp EN, Rupper P, Miller TA. Rovibronic bands of the Ã←X̃ transition of CH3OO and CD3OO detected with cavity ringdown absorption near 1.2–1.4μm. J Chem Phys 2007; 127:044311. [PMID: 17672694 DOI: 10.1063/1.2747616] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We have recorded several rovibronic bands of CH3OO and CD3OO in their A<--X transitions in the range of 1.18-1.40 microm with the cavity ringdown technique. While the electronic origins for these species have been reported previously, many newly observed rovibronic bands are described here. The experimental vibrational frequencies (given as nu in the unit cm(-1) in this paper) for the COO bending (nu8) and COO symmetric stretching (nu7) modes in the A state are 378 and 887 cm(-1) for CH3OO, and 348 and 824 cm(-1) for CD3OO, respectively. In addition, two other vibrational frequencies were observed for the A state of CD3OO, namely, nu5 (954 cm(-1)) and nu6 (971 cm(-1)). These experimental vibrational frequencies for the A state of both CH3OO and CD3OO are in good agreement with predictions from quantum-chemical calculations at the UB3LYP/aug-cc-pVTZ level. The enhanced activity of the nu5 vibrational mode in CD3OO is rationalized by mode mixing with the nu7 mode, as supported by calculations of multidimensional Franck-Condon factors. In addition, many hot bands involving the methyl torsional mode (nu12) are observed for both normal and deuterated methyl peroxy. These bands include the "typical" sequence transitions and some "atypical" ones due to the nature of the eigenvalues and eigenfunctions which are a consequence of the low, but very different, torsional barriers in the X and A states. In addition, the 12(2)2 band in CH3OO and the 12(3)3 band in CD3OO show quite different structures than the origin bands, an effect which results from tunneling splittings comparable to the rotational contour.
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Affiliation(s)
- Chao-Yu Chung
- Department of Applied Chemistry, National Chiao Tung University, 1001, Ta-Hsueh Road, Hsinchu 30010, Taiwan
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140
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Kuwata KT, Valin LC, Converse AD. Quantum chemical and master equation studies of the methyl vinyl carbonyl oxides formed in isoprene ozonolysis. J Phys Chem A 2007; 109:10710-25. [PMID: 16863120 DOI: 10.1021/jp054346d] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methyl vinyl carbonyl oxide is an important intermediate in the reaction of isoprene and ozone and may be responsible for most of the (*)OH formed in isoprene ozonolysis. We use CBS-QB3 calculations and RRKM/master equation simulations to characterize all the pathways leading to the formation of this species, all the interconversions among its four possible conformers, and all of its irreversible isomerizations. Our calculations, like previous studies, predict (*)OH yields consistent with experiment if thermalized syn-methyl carbonyl oxides form (*)OH quantitatively. Natural bond order analysis reveals that the vinyl group weakens the C=O bond of the carbonyl oxide, making rotation about this bond accessible to this chemically activated intermediate. The vinyl group also allows one conformer of the carbonyl oxide to undergo electrocyclization to form a dioxole, a species not previously considered in the literature. Dioxole formation, which has a CBS-QB3 reaction barrier of 13.9 kcal/mol, is predicted to be favored over vinyl hydroperoxide formation, dioxirane formation, and collisional stabilization. Our calculations also predict that two dioxole derivatives, 1,2-epoxy-3-butanone and 3-oxobutanal, should be major products of isoprene ozonolysis.
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Affiliation(s)
- Keith T Kuwata
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, USA.
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141
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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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142
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Cheng XL, Li GX, Wang ZM, Zhao YY, Sun YF. Theoretical Investigation of CH 3CF 2O 2+HOO Reaction. CHINESE J CHEM PHYS 2007. [DOI: 10.1088/1674-0068/20/03/243-248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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143
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144
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Ito A, Sillman S, Penner JE. Effects of additional nonmethane volatile organic compounds, organic nitrates, and direct emissions of oxygenated organic species on global tropospheric chemistry. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2005jd006556] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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145
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Estupiñán EG, Smith JD, Tezaki A, Klippenstein SJ, Taatjes CA. Measurements and Modeling of DO2 Formation in the Reactions of C2D5 and C3D7 Radicals with O2. J Phys Chem A 2007; 111:4015-30. [PMID: 17388267 DOI: 10.1021/jp067602a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Time-resolved production of HO2 and DO2 from the reactions of nondeuterated and deuterated ethyl and propyl radicals with O2 are measured as a function of temperature and pressure in the "transition region" between 623 and 748 K using the technique of laser photolysis/long path frequency modulation spectroscopy. Experimental measurements, using both pulsed-photolytic Cl-atom-initiated oxidation of ethane and propane and direct photolysis of ethyl, n-propyl, and isopropyl iodides, are compared to kinetic models based on the results of time-dependent master equation calculations with ab initio characterization of stationary points. The formation of DO2 and HO2 from the subsequent reaction of the alkyl radicals with O2 is followed by infrared frequency modulation spectroscopy. The concentration of I atoms is simultaneously monitored by direct absorption of a second laser probe on the spin-orbit transition. The kinetic models accurately describe the time scale and amplitude of the DO2 and HO2 formation resulting from C2D5 + O2, n-C3D7 + O2, i-C3D7 + O2, and i-C3H7 + O2. Overall, a very good level of agreement is found between theory and experiments over a wide range of temperatures, pressures, and O2 concentrations. Good agreement is also found between previous literature studies and the theory presented in this work except in the case of the high-temperature rate coefficients for the reaction of i-C3H7 + O2 to form propene. A reinvestigation of the high-temperature kinetics of the i-C3H7 + O2 reaction appears warranted. The results from the present work suggest that the theory for formation of HO2 from the reactions of ethyl and both isomeric forms of propyl radicals with O2 are very well established at this time. It is hoped that these reactions can now form the groundwork for the study and interpretation of larger and more complex R + O2 systems.
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Affiliation(s)
- Edgar G Estupiñán
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, USA
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146
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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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147
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Kovács G, Zádor J, Farkas E, Nádasdi R, Szilágyi I, Dóbé S, Bérces T, Márta F, Lendvay G. Kinetics and mechanism of the reactions of CH3CO and CH3C(O)CH2 radicals with O2. Low-pressure discharge flow experiments and quantum chemical computations. Phys Chem Chem Phys 2007; 9:4142-54. [PMID: 17687464 DOI: 10.1039/b706216h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions CH(3)CO + O(2)--> products (1), CH(3)CO + O(2)--> OH +other products (1b) and CH(3)C(O)CH(2) + O(2)--> products (2) have been studied in isothermal discharge flow reactors with laser induced fluorescence monitoring of OH and CH(3)C(O)CH(2) radicals. The experiments have been performed at overall pressures between 1.33 and 10.91 mbar of helium and 298 +/- 1 K reaction temperature. OH formation has been found to be the dominant reaction channel for CH(3)CO + O(2): the branching ratio, Gamma(1b) = k(1b)/k(1), is close to unity at around 1 mbar, but decreases rapidly with increasing pressure. The rate constant of the overall reaction, k(2), has been found to be pressure dependent: the fall-off behaviour has been analysed in comparison with reported data. Electronic structure calculations have confirmed that at room temperature the reaction of CH(3)C(O)CH(2) with O(2) is essentially a recombination-type process. At high temperatures, the further reactions of the acetonyl-peroxyl adduct may yield OH radicals, but the most probable channel seems to be the O(2)-catalysed keto-enol transformation of acetonyl. Implications of the results for atmospheric modelling studies have been discussed.
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Affiliation(s)
- Gergely Kovács
- Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út 59-67, H-1025 Budapest, Hungary
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148
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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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149
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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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150
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Abate Y, Kleiber PD. Photodissociation spectroscopy of the Mg+-acetic acid complex. J Chem Phys 2006; 125:184310. [PMID: 17115755 DOI: 10.1063/1.2386156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We have studied the structure and photodissociation of Mg(+)-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC(2)H(4)O(2)](+) complex. These isomers include the cis and trans forms of the Mg(+)-acetic acid association complex with Mg(+) bonded to the carbonyl O atom of acetic acid, the Mg(+)-acetic acid association complex with Mg(+) bonded to the hydroxyl O atom of acetic acid, or to a Mg(+)-ethenediol association complex. Photodissociation through the Mg(+)-based 3p<--3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg(+), MgOH(+), Mg(H(2)O)(+), CH(3)CO(+), and MgCH(3) (+). At low energies the dominant reactive quenching pathway is through dehydration to Mg(H(2)O)(+), but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.
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Affiliation(s)
- Yohannes Abate
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
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