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Golin Almeida T, Martí C, Kurtén T, Zádor J, Johansen SL. Theoretical analysis of the OH-initiated atmospheric oxidation reactions of imidazole. Phys Chem Chem Phys 2024. [PMID: 39106054 DOI: 10.1039/d4cp02103g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
Imidazoles are present in Earth's atmosphere in both the gas-phase and in aerosol particles, and have been implicated in the formation of brown carbon aerosols. The gas-phase oxidation of imidazole (C3N2H4) by hydroxyl radicals has been shown to be preferentially initiated via OH-addition to position C5, producing the 5-hydroxyimidazolyl radical adduct. However, the fate of this adduct upon reaction with O2 in the atmospheric gas-phase is currently unknown. We employed an automated approach to investigate the reaction mechanism and kinetics of imidazole's OH-initiated gas-phase oxidation, in the presence of O2 and NOx. The explored mechanism included reactions available to first-generation RO2 radicals, as well as alkoxyl radicals produced from RO2 + NO reactions. Product distributions were obtained by assembling and solving a master equation, under conditions relevant to the Earth's atmosphere. Our calculations show a complex, branched reaction mechanism, which nevertheless converges to yield two major closed-shell products: 4H-imidazol-4-ol (4H-4ol) and N,N'-diformylformamidine (FMF). At 298 K and 1 atm, we estimate the yields of 4H-4ol and FMF from imidazole oxidation initiated via OH-addition to position C5 to be 34 : 66, 12 : 85 and 2 : 95 under 10 ppt, 100 ppt and 1 ppb of NO respectively. This work also revealed O2-migration pathways between the α-N-imino peroxyl radical isomers. This reaction channel is fast for the first-generation RO2 radicals, and may be important during the atmospheric oxidation of other unsaturated organic nitrogen compounds as well.
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Affiliation(s)
- Thomas Golin Almeida
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland.
- Institute for Atmospheric and Earth System Research/Chemistry, University of Helsinki, Helsinki 00014, Finland
| | - Carles Martí
- Combustion Research Facility, Sandia National Laboratories, Livermore 94550, California, USA.
| | - Theo Kurtén
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland.
- Institute for Atmospheric and Earth System Research/Chemistry, University of Helsinki, Helsinki 00014, Finland
| | - Judit Zádor
- Combustion Research Facility, Sandia National Laboratories, Livermore 94550, California, USA.
| | - Sommer L Johansen
- Combustion Research Facility, Sandia National Laboratories, Livermore 94550, California, USA.
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Nguyen LT, Hoang GHL, Tran UNP, Mai TVT, Nguyen HD, Huynh LK. Mechanistic and Kinetic Insights into OH-Initiated Atmospheric Oxidation of Hymexazol: A Computational Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15138-15152. [PMID: 37782022 DOI: 10.1021/acs.est.2c03095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Hymexazol is a volatile fungicide widely used in agriculture, causing its abundance in the atmosphere; thus, its atmospheric fate and conversion are of great importance when assessing its environmental impacts. Herein, we report a theoretical kinetic mechanism for the oxidation of hymexazol by OH radicals, as well as the subsequent reactions of its main products with O2 and then with NO by using the Rice-Ramsperger-Kassel-Marcus-based Master equation kinetic model on the potential energy surface explored at the ROCBS-QB3//M06-2X/aug-cc-pVTZ level. The predicted total rate constants ktotal(T, P) for the reaction between hymexazol and OH radicals show excellent agreement with scarcely available experimental values (e.g., 3.6 × 10-12 vs (4.4 ± 0.8) × 10-12 cm3/molecule/s at T = 300 K and P = 760 Torr); thus, the calculated kinetic parameters can be confidently used for modeling/simulation of N-heterocycle-related applications under atmospheric and even combustion conditions. The model shows that 3,4-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-5-yl (IM2), 3,5-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-4-yl (IM3), and (3-hydroxy-1,2-oxazol-5-yl)methyl (P8) are the main primary intermediates, which form the main secondary species of (3,4-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-5-yl)dioxidanyl (IM4), (3,5-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-4-yl)dioxidanyl (IM7), and ([(3-hydroxy-1,2-oxazol-5-yl)methyl]dioxidanyl (IM11), respectively, through the reactions with O2. The main secondary species then can react with NO to form the main tertiary species, namely, (3,4-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-5-yl)oxidanyl (P19), (3,5-dihydroxy-5-methyl-4,5-dihydro-1,2-oxazol-4-yl)oxidanyl (P21), and [(3-hydroxy-1,2-oxazol-5-yl)methyl]oxidanyl (P23), respectively, together with NO2. Besides, hymexazol could be a persistent organic pollutant in the troposphere due to its calculated half-life τ1/2 of 13.7-68.1 h, depending on the altitude.
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Affiliation(s)
- Loc T Nguyen
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- School of Chemical and Environmental Engineering, International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Gia-Huy L Hoang
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- School of Chemical and Environmental Engineering, International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Uyen N-P Tran
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- School of Chemical and Environmental Engineering, International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Tam V-T Mai
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- Molecular Science and Nano-Materials Lab, Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- University of Science, 227 Nguyen Van Cu, Ward 4, District 5, Ho Chi Minh City 700000, Vietnam
| | - Huy D Nguyen
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- University of Science, 227 Nguyen Van Cu, Ward 4, District 5, Ho Chi Minh City 700000, Vietnam
| | - Lam K Huynh
- Vietnam National University, Ho Chi Minh City, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- School of Chemical and Environmental Engineering, International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
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Zhang M, Xi Z, Gong Z, Dong Y. Reaction Mechanism of Nitrogen-Containing Heterocyclic Compounds Affecting Coal Spontaneous Combustion. ACS OMEGA 2023; 8:35295-35306. [PMID: 37780018 PMCID: PMC10536888 DOI: 10.1021/acsomega.3c05088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023]
Abstract
To uncover the reaction mechanism of nitrogen-containing heterocyclic compounds affecting coal self-heating, quantum chemical calculations and X-ray photoelectron spectroscopy (XPS) experiments were applied to elucidate the reaction pathways and thermodynamic characteristics of pyrrole, pyridine, indole, quinoline, and carbazole. Results show that in pyrrole, pyridine, indole, quinoline, and carbazole, the reaction with O2 captures the H atom and leads to the formation of ·OOH and pyrrolyl, pyridinyl, indolyl, quinolinyl, and carbazolyl radicals, respectively. The activation energies are 118.15, 86.642, 34.132, 21.004, and 47.259 kJ/mol, respectively. ROO· formed by spontaneous adsorption of O2 by nitrogen-containing radicals undergoes self-reaction, and the O-O bond is broken and dehydrogenated to generate ·OH. Subsequently, at room temperature, ·OH reacts with pyrrole, pyridine, indole, quinoline, and carbazole, resulting in the formation of H2O and pyrrolyl, pyridinyl, indolyl, quinolinyl, and carbazolyl radicals, respectively, thereby forming a cyclic chain reaction. The XPS analysis yielded the following findings: (i) when the temperature rises to 70 °C, the N-5 and N-6 content decrease, which is attributed to the activation energy; (ii) when the temperature reaches 200 °C, the N-5 content decreases, which can be attributed to the activation energy required for the oxidation of pyrrole (118.5 kJ/mol).
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Affiliation(s)
- Mengmeng Zhang
- School of Environmental
Science and Safety Engineering, Tianjin
University of Technology, Tianjin 300384, China
- Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling
Technology, Tianjin 300384, China
| | - Zhilin Xi
- School of Environmental
Science and Safety Engineering, Tianjin
University of Technology, Tianjin 300384, China
- Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling
Technology, Tianjin 300384, China
| | - Zhensen Gong
- School of Environmental
Science and Safety Engineering, Tianjin
University of Technology, Tianjin 300384, China
- Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling
Technology, Tianjin 300384, China
| | - Yubo Dong
- School of Environmental
Science and Safety Engineering, Tianjin
University of Technology, Tianjin 300384, China
- Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling
Technology, Tianjin 300384, China
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Theoretical Perspectives on the Gas-Phase Oxidation Mechanism and Kinetics of Carbazole Initiated by OH Radical in the Atmosphere. ATMOSPHERE 2022. [DOI: 10.3390/atmos13071129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Carbazole is one of the typical heterocyclic aromatic compounds (NSO-HETs) observed in polluted urban atmosphere, which has become a serious environmental concern. The most important atmospheric loss process of carbazole is the reaction with OH radical. The present work investigated the mechanism of OH-initiated atmospheric oxidation degradation of carbazole by using density functional theory (DFT) calculations at the M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. The rate constants were determined by the Rice–Ramsperger–Kassel–Marcus (RRKM) theory. The lifetime of carbazole determined by OH was compared with other typical NSO-HETs. The theoretical results show that the degradation of carbazole initiated by OH radical includes four types of reactions: OH additions to “bend” C atoms, OH additions to “benzene ring” C atoms, H abstractions from C-H bonds and the H abstraction from N-H bond. The OH addition to C1 atom and the H abstraction from N-H bond are energetically favorable. The main oxidation products are hydroxycarbazole, dialdehyde, carbazolequinone, carbazole-ol, hydroxy-carbazole-one and hydroperoxyl-carbazole-one. The calculated overall rate constant of carbazole oxidation by OH radical is 6.52 × 10−12 cm3 molecule−1 s−1 and the atmospheric lifetime is 37.70 h under the condition of 298 K and 1 atm. The rate constant of carbazole determined by OH radical is similar with that of dibenzothiophene oxidation but lower than those of pyrrole, indole, dibenzofuran and fluorene. This work provides a theoretical investigation of the oxygenated mechanism of NSO-HETs in the atmosphere and should help to clarify their potential health risk for determining the reaction pathways and environmental influence of carbazole.
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Zhang Y, Cheng Y, Zhang T, Wang R, Ji J, Xia Y, Makroni L, Wang Z, M B. A computational study of the HO2 + SO3 → HOSO2 + 3O2 reaction catalyzed by water monomer, water dimer and small clusters of sulfuric acid: kinetics and atmospheric implications. Phys Chem Chem Phys 2022; 24:18205-18216. [DOI: 10.1039/d1cp03318b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, the reaction mechanisms and kinetics for the HO2 + SO3 → HOSO2 + 3O2 reaction catalyzed by water monomer, water dimer and small clusters of sulfuric acid have been...
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Giri BR, V.-T. Mai T, Assali M, Nguyen TTD, Nguyen H, Szőri M, Huynh LK, Fittschen C, Farooq A. Reaction Kinetics of 1,4-Cyclohexadiene with OH radicals : An Experimental and Theoretical Study. Phys Chem Chem Phys 2022; 24:7836-7847. [DOI: 10.1039/d1cp04964j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work presents OH-initiated oxidation kinetics of 1,4-cyclochexadiene (1,4-CHD). Temperature dependence of the reaction was investigated by utilizing laser flash photolysis flow reactor and laser-induced fluorescence (LPFR/LIF) technique over the...
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Wu X, Hou Q, Huang J, Chai J, Zhang F. Exploring the OH-initiated reactions of styrene in the atmosphere and the role of van der Waals complex. CHEMOSPHERE 2021; 282:131004. [PMID: 34082313 DOI: 10.1016/j.chemosphere.2021.131004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/19/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
Reacting with OH provides a major sink for styrene in the atmosphere, with three possible pathways including OH-addition, H-abstraction and addition-dissociation reactions. However, the total rate coefficients of styrene + OH were measured as 1.2-6.2 × 10-11 cm3 molecule-1 s-1 under atmospheric conditions, varying by a maximum factor of 5. On the other hand, only one theoretical work reported this rate coefficient as 19.1 × 10-11 cm3 molecule-1 s-1, which exhibits up to 16 times that measured in laboratory studies. In the present study, the reaction kinetics of styrene + OH was extensively studied with high-level quantum chemical methods combined with RRKM/master equation simulations. In particular, we carried out theoretical treatments for the formation of pre-reaction Van der Waals complexes of styrene + OH, and examined their influence on the reaction kinetics. The total rate coefficient for styrene + OH is calculated to be 1.7 × 10-11 cm3 molecule-1 s-1 at 300 K, 1 atm. The main products are addβ (88.2%), add5 (6.9%), addα (1.9%) and add3 (1.7%). Using our computed rate coefficient and the global atmospheric hydroxyl radical concentration (2 × 106 radicals per cm3), the lifetime of styrene in the atmosphere is estimated at 8.0 h. The degradation of styrene might be negligible for the formation of ozone in the atmosphere based upon the photochemical ozone creation potentials calculation. The computed product yields indicate that addβ via subsequent reactions could significantly produce formaldehyde and benzaldehyde that were observed in previous experimental studies on styrene oxidation, and contribute to the formation of secondary organic aerosols.
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Affiliation(s)
- Xiaoqing Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, PR China; National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, PR China
| | - Qifeng Hou
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, PR China
| | - Jiabin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, PR China
| | - Jiajue Chai
- Institute at Brown for Environment and Society, And Department of Earth, Environmental and Planetary Sciences, Brown University, 182 Hope St., Providence, RI, 02912, USA
| | - Feng Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, PR China.
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Baruah SD, Deka RC, Gour NK, Paul S. Atmospheric insight into the reaction mechanism and kinetics of isopropenyl methyl ether (i-PME) initiated by OH radicals and subsequent oxidation of product radicals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:45646-45662. [PMID: 33876365 DOI: 10.1007/s11356-021-13928-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Studies on primary gas-phase reactions of emitted saturated and unsaturated ethers with oxidants and subsequent secondary reactions of product radicals with O2 in the presence of NO are important in their atmospheric chemical processes. To accomplish these findings, we have examined the chemistry of OH-initiated oxidation of isopropenyl methyl ether (i-PME) CH3C(CH2)OCH3 by electronic structure ca using density functional theory. Our energetic calculations show that OH additions to carbon-carbon double bonds of i-PME are more favorable reaction pathways than H-abstraction reactions from the various CH sites of the titled molecule. The rate constant values which are obtained from the transition state theory also signify that OH-addition reactions have faster reaction rates than H-abstraction reactions. Our calculated total rate constant of the reaction is found 9.90 × 10-11 cm3 molecule-1 s-1. The percentage branching ratio calculations imply that OH-addition reactions have 98.09% contribution in the total rate constant. The atmospheric lifetime of i-PME is found to be 2.8 h. Further, we have identified 2-hydroxy-2-methoxypropanol, methyl acetate, methy-1,2-hydroxyacetate and 1-hydroxypropane-2-one, 1,2-dihydroxypropan-2-yl format, 2-hydroxyacetic acid, acetic acid, and formaldehyde from the secondary oxidation of product radicals.
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Affiliation(s)
- Satyajit Dey Baruah
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India
| | - Ramesh Chandra Deka
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India
| | - Nand Kishor Gour
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India.
| | - Subrata Paul
- Department of Chemistry, Assam University, Silchar, Assam, 788011, India.
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Mai TVT, Nguyen TTD, Nguyen HT, Nguyen TT, Huynh LK. New Mechanistic Insights into Atmospheric Oxidation of Aniline Initiated by OH Radicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7858-7868. [PMID: 34043323 DOI: 10.1021/acs.est.1c01865] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study theoretically reports the comprehensive kinetic mechanism of the aniline + OH reaction in the range of 200-2000 K and 0.76-7600 Torr. The temperature- and pressure-dependent behaviors, including time-resolved species profiles and rate coefficients, were studied within the stochastic RRKM-based master equation framework with the reaction energy profile, together with molecular properties of the species involved, characterized at the M06-2X/aug-cc-pVTZ level. Hindered internal rotation and Eckart tunneling treatments were included. The H-abstraction from the -NH2 moiety (to form C6H5NH (P1)) is found to prevail over the OH-addition on the C atom at the ortho site of aniline (to form 6-hydroxy-1-methylcyclohexa-2,4-dien-1-yl (I2)) with the atmospheric rate expressions (in cm3/molecule/s) as kabstraction(P1) = 3.41 × 101 × T-4.56 × exp (-255.2 K/T) for 200-2000 K and kaddition(I2) = 3.68 × 109 × T-7.39 × exp (-1163.9 K/T) for 200-800 K. The U-shaped temperature-dependent characteristics and weakly positive pressure dependence at low temperatures (e.g., T ≤ 800 K and P = 760 Torr) of ktotal(T) are also observed. The disagreement in ktotal(T) between the previous calculations and experimental studies is also resolved, and atmospheric aniline is found to be primarily removed by OH radicals (τOH ∼ 1.1 h) in the daytime. Also, via TD-DFT simulations, it is recommended to include P1 and I2 in any atmospheric photolysis-related model.
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Affiliation(s)
- Tam V-T Mai
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City 700000, Vietnam
- University of Science, 227 Nguyen Van Cu, Ward 4, District 5, Ho Chi Minh City 700000, Vietnam
- Vietnam National University, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Thi T-D Nguyen
- Vietnam National University, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Hieu T Nguyen
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City 700000, Vietnam
| | - Trang T Nguyen
- Vietnam National University, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
| | - Lam K Huynh
- Vietnam National University, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
- International University, Quarter 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam
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Mai TVT, Huynh LK. Comment on “Atmospheric chemistry of oxazole: the mechanism and kinetic studies on oxidation reaction initiated by OH radicals” by A. Shiroudi, M. A. Abdel-Rahman, A. M. El-Nahas and M. Altarawneh, New J. Chem., 2021, 45, 2237. NEW J CHEM 2021. [DOI: 10.1039/d1nj01020d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The large kinetic discrepancy between computational and experimental studies is resolved using the rigorous stochastic RRKM-based master-equation rate model. Detailed mechanistic insights are also revealed to advance its related applications.
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Affiliation(s)
- Tam V.-T. Mai
- University of Science
- Ho Chi Minh City
- Ho Chi Minh City
- Vietnam
- Molecular Science and Nano-Materials Lab
| | - Lam K. Huynh
- Vietnam National University HoChiMinh City
- Quarter 6, Linh Trung Ward
- Ho Chi Minh City
- Vietnam
- International University
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Mai TVT, Huynh LK. Detailed kinetics of hydrogen abstraction from trans-decalin by OH radicals: the role of hindered internal rotation treatment. Phys Chem Chem Phys 2020; 22:25740-25746. [PMID: 33146635 DOI: 10.1039/d0cp04314a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, the detailed kinetic mechanism of the trans-decalin + OH reaction is firstly investigated for a wide range of conditions (i.e., T = 200-2000 K & P = 0.76-76 000 Torr) using the M06-2X/aug-cc-pVTZ level and stochastic Rice-Ramsperger-Kassel-Marcus based master equation (RRKM-ME) rate model, which includes corrections of the hindered internal rotor (HIR) and tunneling effects. Our predicted global rate constant excellently matches with the scarce experimental measurement (R. Atkinson, et al. Int. J. Chem. Kinet., 1983, 15, 37-50). The H-abstraction channel from Cα of trans-decalin is found to be dominant at low temperatures. A U-shaped temperature-dependent behavior and slightly positive pressure-dependence at low temperatures (e.g., T ≤ 400 K & P = 760 Torr) of the total rate constants are also observed. Detailed analysis reveals that the HIR treatment is essential to capture the kinetic behavior while the tunneling correction only plays a minor role.
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Affiliation(s)
- Tam V-T Mai
- Molecular Science and Nano-Materials Lab, Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam.
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