1
|
Gao Q, Shen C, Zhang H, Long B, Truhlar DG. Quantitative kinetics reveal that reactions of HO 2 are a significant sink for aldehydes in the atmosphere and may initiate the formation of highly oxygenated molecules via autoxidation. Phys Chem Chem Phys 2024; 26:16160-16174. [PMID: 38787752 DOI: 10.1039/d4cp00693c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
Large aldehydes are widespread in the atmosphere and their oxidation leads to secondary organic aerosols. The current understanding of their chemical transformation processes is limited to hydroxyl radical (OH) oxidation during daytime and nitrate radical (NO3) oxidation during nighttime. Here, we report quantitative kinetics calculations of the reactions of hexanal (C5H11CHO), pentanal (C4H9CHO), and butanal (C3H7CHO) with hydroperoxyl radical (HO2) at atmospheric temperatures and pressures. We find that neither tunneling nor multistructural torsion anharmonicity should be neglected in computing these rate constants; strong anharmonicity at the transition states is also important. We find rate constants for the three reactions in the range 3.2-7.7 × 10-14 cm3 molecule-1 s-1 at 298 K and 1 atm, showing that the HO2 reactions can be competitive with OH and NO3 oxidation under some conditions relevant to the atmosphere. Our findings reveal that HO2-initiated oxidation of large aldehydes may be responsible for the formation of highly oxygenated molecules via autoxidation. We augment the theoretic studies with laboratory flow-tube experiments using an iodide-adduct time-of-flight chemical ionization mass spectrometer to confirm the theoretical predictions of peroxy radicals and the autoxidation pathway. We find that the adduct from HO2 + C5H11CHO undergoes a fast unimolecular 1,7-hydrogen shift with a rate constant of 0.45 s-1. We suggest that the HO2 reactions make significant contributions to the sink of aldehydes.
Collapse
Affiliation(s)
- Qiao Gao
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang 550025, China.
| | - Chuanyang Shen
- Department of Chemistry, University of California, Riverside, California, 92507, USA.
| | - Haofei Zhang
- Department of Chemistry, University of California, Riverside, California, 92507, USA.
| | - Bo Long
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang 550025, China.
- College of Materials Science and Engineering, Guizhou Minzu university, Guiyang 550025, China
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
| |
Collapse
|
2
|
Lin J, Zhao H, Cao H, Zhao Y, Chen C. Photoinduced release of odorous volatile organic compounds from aqueous pollutants: The role of reactive oxygen species in increasing risk during cross-media transformation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153397. [PMID: 35122842 DOI: 10.1016/j.scitotenv.2022.153397] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Photoinduced volatile organic compounds (VOCs) release from fatty alcohols at the air-water interface, has attracted considerable attention. This paper comprehensively explores the release of odorous VOCs from aqueous micropollutants under photoirradiation, especially in terms of the important role of the reactive oxygen species (ROS) in increased risk by cross-media transformation. The formation and distribution of photoinduced VOCs produced by aqueous benzyl alcohol (BzOH), a common ingredient in personal care products, were monitored in situ by online gas chromatography equipped with mass spectrometry and flame ionization detector (GC-MS/FID). The photoreaction of BzOH followed first-order kinetics with a rate constant of 0.0158/min under air. After 180 min of ultraviolet irradiation, the accumulated output of the gas-phase products benzene and benzaldehyde (BA) reached 3.8 μmol and 2.6 μmol respectively, being approximately 10 times that under nitrogen. According to electron paramagnetic resonance measurements, singlet oxygen mainly promoted the oxidation of BzOH to BA, which was an important intermediate producing benzene via photocleavage. Odorous alicyclic hydrocarbons were also generated through photorearrangement under nitrogen. On the other hand, the Henry's law constants of the main products were much lower than those of BzOH, indicating that the photoproducts would volatilize from the aqueous phase into the gas phase. The odor threshold of gas-phase products decreased to varying degrees after photoirradiation. Especially for BA, one of the main products, its odor threshold decreased 130 times compared with BzOH. This study shows that the risk of cross-media pollution could significantly increase due to the transformation of aqueous pollutants into odorous VOCs under photoirradiation and provides new insight into its risk prevention.
Collapse
Affiliation(s)
- Jingyi Lin
- Beijing Engineering Research Center of Process Pollution Control, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - He Zhao
- Beijing Engineering Research Center of Process Pollution Control, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China.
| | - Hongbin Cao
- Beijing Engineering Research Center of Process Pollution Control, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuehong Zhao
- Beijing Engineering Research Center of Process Pollution Control, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China; National Basic Public Science Data Center, Beijing 100190, China
| | - Chuncheng Chen
- University of Chinese Academy of Sciences, Beijing 100049, China; Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
3
|
Blázquez S, González D, Neeman EM, Ballesteros B, Agúndez M, Canosa A, Albaladejo J, Cernicharo J, Jiménez E. Gas-phase kinetics of CH 3CHO with OH radicals between 11.7 and 177.5 K. Phys Chem Chem Phys 2020; 22:20562-20572. [PMID: 32966434 PMCID: PMC7116299 DOI: 10.1039/d0cp03203d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase reactions in the interstellar medium (ISM) are a source of molecules in this environment. The knowledge of the rate coefficient for neutral-neutral reactions as a function of temperature, k(T), is essential to improve astrochemical models. In this work, we have experimentally measured k(T) for the reaction between the OH radical and acetaldehyde, both present in many sources of the ISM. Laser techniques coupled to a CRESU system were used to perform the kinetic measurements. The obtained modified Arrhenius equation is k(T = 11.7-177.5 K) = (1.2 ± 0.2) × 10-11 (T/300 K)-(1.8±0.1) exp-{(28.7 ± 2.5)/T} cm3 molecule-1 s-1. The k(T) value of the title reaction has been measured for the first time below 60 K. No pressure dependence of k(T) was observed at ca. 21, 50, 64 and 106 K. Finally, a pure gas-phase model indicates that the title reaction could become the main CH3CO formation pathway in dark molecular clouds, assuming that CH3CO is the main reaction product at 10 K.
Collapse
Affiliation(s)
- Sergio Blázquez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain.
| | - Daniel González
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain.
| | - Elias M Neeman
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain.
| | - Bernabé Ballesteros
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain. and Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071, Ciudad Real, Spain
| | - Marcelino Agúndez
- Molecular Astrophysics Group, Instituto de Física Fundamental (IFF-CSIC), Consejo Superior de Investigaciones Científicas, C/Serrano 123, 28006, Madrid, Spain
| | - André Canosa
- CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Université de Rennes, F-35000 Rennes, France
| | - José Albaladejo
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain. and Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071, Ciudad Real, Spain
| | - José Cernicharo
- Molecular Astrophysics Group, Instituto de Física Fundamental (IFF-CSIC), Consejo Superior de Investigaciones Científicas, C/Serrano 123, 28006, Madrid, Spain
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1B, 13071, Ciudad Real, Spain. and Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071, Ciudad Real, Spain
| |
Collapse
|
4
|
Sadhukhan T, Das D, Kalekar P, Avasare V, Pal S. Fenton’s Reagent Catalyzed Release of Carbon Monooxide from 1,3-Dihydroxy Acetone. J Phys Chem A 2017; 121:4569-4577. [DOI: 10.1021/acs.jpca.7b03676] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tumpa Sadhukhan
- Department
of Chemistry, Indian Institution of Technology Bombay, Mumbai 400076, India
| | - Dharitri Das
- Department
of Chemistry, Indian Institution of Technology Bombay, Mumbai 400076, India
| | - Pratik Kalekar
- Department
of Chemistry, Sir Parashurambhau College, Pune 411030, India
| | - Vidya Avasare
- Department
of Chemistry, Sir Parashurambhau College, Pune 411030, India
| | - Sourav Pal
- Department
of Chemistry, Indian Institution of Technology Bombay, Mumbai 400076, India
| |
Collapse
|
5
|
Pipaliya BV, Chakraborti AK. Cross-Dehydrogenative Coupling of Heterocyclic Scaffolds with Unfunctionalized Aroyl Surrogates by Palladium(II) Catalyzed C(sp2)-H Aroylation through Organocatalytic Dioxygen Activation. J Org Chem 2017; 82:3767-3780. [DOI: 10.1021/acs.joc.7b00226] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Bhavin V. Pipaliya
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector
67, S. A. S. Nagar, Punjab 160 062, India
| | - Asit K. Chakraborti
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector
67, S. A. S. Nagar, Punjab 160 062, India
| |
Collapse
|
6
|
Howes NUM, Lockhart JPA, Blitz MA, Carr SA, Baeza-Romero MT, Heard DE, Shannon RJ, Seakins PW, Varga T. Observation of a new channel, the production of CH 3, in the abstraction reaction of OH radicals with acetaldehyde. Phys Chem Chem Phys 2016; 18:26423-26433. [PMID: 27711478 DOI: 10.1039/c6cp03970g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using laser flash photolysis coupled to photo-ionization time-of-flight mass spectrometry (PIMS), methyl radicals (CH3) have been detected as primary products from the reaction of OH radicals with acetaldehyde (ethanal, CH3CHO) with a yield of ∼15% at 1-2 Torr of helium bath gas. Supporting measurements based on laser induced fluorescence studies of OH recycling in the OH/CH3CHO/O2 system are consistent with the PIMS study. Master equation calculations suggest that the origin of the methyl radicals is from prompt dissociation of chemically activated acetyl products and hence is consistent with previous studies which have shown that abstraction, rather than addition/elimination, is the sole route for the OH + acetaldehyde reaction. However, the observation of a significant methyl product yield suggests that energy partitioning in the reaction is different from the typical early barrier mechanism where reaction exothermicity is channeled preferentially into the newly formed bond. The master equation calculations predict atmospheric yields of methyl radicals of ∼9%. The implications of the observations in atmospheric and combustion chemistry are briefly discussed.
Collapse
Affiliation(s)
- Neil U M Howes
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | | | - Mark A Blitz
- National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
| | - Scott A Carr
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | | | - Dwayne E Heard
- National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
| | - Robin J Shannon
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Paul W Seakins
- National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
| | - T Varga
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| |
Collapse
|
7
|
Carey PE, Stevens PS. Experimental and Theoretical Study of the Kinetics of the OH + Propionaldehyde Reaction between 277 and 375 K at Low Pressure. J Phys Chem A 2016; 120:1377-85. [PMID: 26356683 DOI: 10.1021/acs.jpca.5b05179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Measurements of the rate constant for the reaction of OH radicals with propionaldehyde as a function of temperature were performed using low-pressure discharge-flow tube techniques coupled with laser-induced fluorescence detection of OH radicals. The measured room-temperature rate constant of (1.51 ± 0.22) × 10(-11) cm(3) molecules(-1) s(-1) at 4 Torr was generally lower but in reasonable agreement with previous absolute and relative rate studies at higher pressures. Measurements as a function of temperature resulted in an Arrhenius expression of (2.3 ± 0.4) × 10(-11) exp[(-110 ± 50)/T] cm(3) molecules(-1) s(-1) between 277 and 375 K at 4 Torr. The observed temperature dependence at low pressure is in contrast to previous measurements of a negative temperature dependence at higher pressures. Ab initio calculations of the potential energy surface for this reaction suggest that the primary reaction pathway involves the formation of a hydrogen-bonded prereactive complex, which could account for the difference in the observed temperature dependence at lower and higher pressures.
Collapse
Affiliation(s)
- Paul E Carey
- School of Public and Environmental Affairs and Department of Chemistry Indiana University , Bloomington, Indiana 47405, United States
| | - Philip S Stevens
- School of Public and Environmental Affairs and Department of Chemistry Indiana University , Bloomington, Indiana 47405, United States
| |
Collapse
|
8
|
Bedjanian Y, Morin J, Romanias MN. Gas-Phase Reaction of Hydroxyl Radical with p-Cymene over an Extended Temperature Range. J Phys Chem A 2015; 119:11076-83. [DOI: 10.1021/acs.jpca.5b08478] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuri Bedjanian
- Institut de Combustion, Aérothermique,
Réactivité et Environnement (ICARE), CNRS and Université d’Orléans, 45071 Cedex 2, Orléans, France
| | - Julien Morin
- Institut de Combustion, Aérothermique,
Réactivité et Environnement (ICARE), CNRS and Université d’Orléans, 45071 Cedex 2, Orléans, France
| | - Manolis N. Romanias
- Institut de Combustion, Aérothermique,
Réactivité et Environnement (ICARE), CNRS and Université d’Orléans, 45071 Cedex 2, Orléans, France
| |
Collapse
|
9
|
Li M, Zhang JS, Shen W, Meng QX. Quantum chemical study on reaction of acetaldehyde with hydroxyl radical. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.20040220806] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
10
|
Vöhringer-Martinez E, Tellbach E, Liessmann M, Abel B. Role of Water Complexes in the Reaction of Propionaldehyde with OH Radicals. J Phys Chem A 2010; 114:9720-4. [DOI: 10.1021/jp101804j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. Vöhringer-Martinez
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Avenida Vicuña Maquenna 4860, Santiago de Chile, Chile, Institut für Physikalische Chemie der Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linné-Strasse 2, D-04103 Leipzig, Germany
| | - E. Tellbach
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Avenida Vicuña Maquenna 4860, Santiago de Chile, Chile, Institut für Physikalische Chemie der Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linné-Strasse 2, D-04103 Leipzig, Germany
| | - M. Liessmann
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Avenida Vicuña Maquenna 4860, Santiago de Chile, Chile, Institut für Physikalische Chemie der Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linné-Strasse 2, D-04103 Leipzig, Germany
| | - B. Abel
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Avenida Vicuña Maquenna 4860, Santiago de Chile, Chile, Institut für Physikalische Chemie der Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linné-Strasse 2, D-04103 Leipzig, Germany
| |
Collapse
|
11
|
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]
|
12
|
Rosado-Reyes CM, Francisco JS. Atmospheric oxidation pathways of propane and its by-products: Acetone, acetaldehyde, and propionaldehyde. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007566] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Carl SA, Vereecken L, Peeters J. Kinetic parameters for gas-phase reactions: experimental and theoretical challenges. Phys Chem Chem Phys 2007; 9:4071-84. [PMID: 17687459 DOI: 10.1039/b705505f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article aims to illustrate the added value provided to experimental kinetics investigations by complementary theoretical kinetics studies, using as examples (i) reactions of two major hydrocarbon flame radicals, HCCO and C(2)H, and (ii) reactions of several oxygenated organic compounds with hydroxyl radicals of interest to atmospheric chemistry. The first part, on HCCO and C(2)H kinetics, does not attempt to give an extensive literature review, but rather addresses some major experimental techniques, mainly specific ones, that have allowed a great part of the available reactivity databases on these two species to be established. For several key reactions, it is shown how potential energy surfaces and statistical rate predictions based thereon have provided insight into the molecular mechanisms and have allowed estimates of product distributions as well as reliable extrapolations of experimental rate coefficients and branching ratios to higher temperatures. The second part addresses current issues in atmospheric chemistry relating mainly to hydroxyl radical reactions with oxygenated organics, and focuses on the experimental characterization of the often unusual temperature dependence of their rate coefficients and on the theoretical rationalization thereof, through the formation of hydrogen-bonded pre-reactive complexes and resulting tunnelling-enhanced H-abstraction. Finally, the development of general structure-activity relationships for OH reactions with organics, H-abstractions as well as OH-additions for unsaturated compounds, is briefly discussed.
Collapse
Affiliation(s)
- S A Carl
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
| | | | | |
Collapse
|
14
|
Taylor PH, Yamada T, Marshall P. The reaction of OH with acetaldehyde and deuterated acetaldehyde: Further insight into the reaction mechanism at both low and elevated temperatures. INT J CHEM KINET 2006. [DOI: 10.1002/kin.20179] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
15
|
De Smedt F, Bui XV, Nguyen TL, Peeters J, Vereecken L. Theoretical and Experimental Study of the Product Branching in the Reaction of Acetic Acid with OH Radicals. J Phys Chem A 2005; 109:2401-9. [PMID: 16839011 DOI: 10.1021/jp044679v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The product distribution of the reaction of acetic acid, CH(3)COOH, with hydroxyl radicals, OH, was studied experimentally and theoretically. Mass-spectrometric measurements at 290 K and 2 Torr of He of the CO(2) yield versus the loss of acetic acid yielded a branching fraction of 64 +/- 14% for the abstraction of the acidic hydrogen as follows: CH(3)COOH + OH --> CH(3)COO + H(2)O --> CH(3) + CO(2) + H(2)O. A quantum chemical and theoretical kinetic analysis showed that the abstraction of the acidic hydrogen is enhanced relative to the abstraction of -CH(3) hydrogens because of the formation of a strong pre-reactive H-bonded complex, where the H-bonds are retained in the H-abstraction transition state. The potential energy surface of the reaction is explored in detail, and the reaction products of the individual channels are identified. The theoretical product branching is found to be critically dependent on the energetic and rovibrational differences between the H-abstraction transition states.
Collapse
Affiliation(s)
- F De Smedt
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | | | | | | | | |
Collapse
|
16
|
Galano A, Alvarez-Idaboy JR, Ruiz-Santoyo ME, Vivier-Bunge A. Glycolaldehyde + OH Gas Phase Reaction: A Quantum Chemistry + CVT/SCT Approach. J Phys Chem A 2004; 109:169-80. [PMID: 16839103 DOI: 10.1021/jp047490s] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We present a theoretical study of the mechanism and kinetics of the OH hydrogen abstraction from glycolaldehyde. Optimum geometries, frequencies, and gradients have been computed at the BHandHLYP/6-311++G(d,p) level of theory for all stationary points, as well as for additional points along the minimum energy path (MEP). Energies are obtained by single-point calculations at the above geometries using CCSD(T)/6-311++G(d,p) to produce the potential energy surface. The rate coefficients are calculated for the temperature range 200-500 K by using canonical variational theory (CVT) with small-curvature tunneling (SCT) corrections. Our analysis suggests a stepwise mechanism involving the formation of a reactant complex in the entrance channel and a product complex in the exit channel, for all the modeled paths. The overall agreement between the calculated and experimental kinetic data that are available at 298 K is very good. This agreement supports the reliability of the parameters obtained for the temperature dependence of the glycolaldehyde + OH reaction. The expressions that best describe the studied reaction are k(overall) = 7.76 x 10(-13) e(1328/)(RT) cm(3).molecule(-1).s(-1) and k(overall) = 1.09 x 10(-21)T(3.03) e(3187/)(RT) cm(3) molecule(-1) s(-1), for the Arrhenius and Kooij approaches, respectively. The predicted activation energy is (-1.36 +/- 0.03) kcal/mol, at about 298 K. The agreement between the calculated and experimental branching ratios is better than 10%. The intramolecular hydrogen bond in OO-s-cis glycolaldehyde is found to be responsible for the discrepancies between SAR and experimental rate coefficients.
Collapse
Affiliation(s)
- Annia Galano
- Instituto Mexicano del Petróleo, Eje Central Lazaro Cardenas 152, 007730 México D. F., México.
| | | | | | | |
Collapse
|
17
|
Mellouki A, Le Bras G, Sidebottom H. Kinetics and Mechanisms of the Oxidation of Oxygenated Organic Compounds in the Gas Phase. Chem Rev 2003; 103:5077-96. [PMID: 14664644 DOI: 10.1021/cr020526x] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- A Mellouki
- Laboratoire de Combustion et Systèmes Réactifs, Centre National de Recherche Scientifique, 1C Avenue de la recherche scientifique, 45071 Orléans Cedex 02, France
| | | | | |
Collapse
|