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Rais N, Salta Z, Tasinato N. Theoretical investigation of the OH-initiated atmospheric degradation mechanism of CX 2CHX (X = H, F, Cl) by advanced quantum chemical and transition state theory methods. Phys Chem Chem Phys 2024; 26:19976-19991. [PMID: 38995148 DOI: 10.1039/d4cp01453g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Halogenated olefins are anthropogenic compounds with many industrial applications but at the same time raising many environmental and health concerns. Gas-phase electrophilic addition of the OH radical to the olefinic CC bond represents the primary sink for these chemicals in the atmosphere, with the degree and type of halogenation playing a significant role in their overall reactivity. In this work, we present a theoretical investigation of the reaction mechanisms and kinetics for the reactions between the OH radical and CH2CH2 (ethylene, ETH), CF2CHF (trifluoroethylene, TFE) and CCl2CHCl (trichloroethylene, TCE), simulated by state-of-the-art protocols and methods, with the aim of providing a detailed interpretation of the available experimental results, as well as new data of relevance to tropospheric chemistry. Specifically, potential energy surfaces (PESs) are obtained using the jun-Cheap (jChS) composite scheme, whereas temperature and pressure dependent rate coefficients and product distributions in the 100-600 K temperature range are calculated within the Rice-Ramsperger-Kassel-Marcus/master equation (RRKM/ME) framework. The rates for barrierless channels are obtained from variable reaction coordinate-variational transition state theory (VRC-VTST) combined with the two transition state model. While the reactions with ETH and TFE proceed mainly via the formation of addition adducts at P = 1 atm and T = 298 K, the dominant channel for TCE is the Cl-elimination reaction. Global rate constants for the two halogenated olefins, TFE and TCE, are found to be pressure-independent, contrary to the case of ETH. The computed rate constants, as well as their temperature and pressure dependence, are in remarkable agreement with the available experimental data, and they are used to derive atmospheric lifetimes (τ) for both TFE and TCE as a function of altitude (h) in the atmosphere, by taking into account variations in the rate coefficients (k (T, P)) and [OH] concentration.
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Affiliation(s)
- Nadjib Rais
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
- IUSS Scuola Universitaria Superiore, Piazza della Vittoria 15, I-27100, Pavia, Italy
| | - Zoi Salta
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
| | - Nicola Tasinato
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
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2
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Liang Y, Zhu Y, Chen J, Lu X, Zhou CW. Theoretical investigation on isomerization and decomposition reactions of pentanol radicals-part II: linear pentanol isomers. Phys Chem Chem Phys 2024; 26:15494-15510. [PMID: 38752432 DOI: 10.1039/d4cp00903g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
High-level ab initio calculations are conducted for studying the kinetics of three linear pentanol radicals generated through H-atom abstraction reactions. The species involved are optimized using the M06-2X/6-311++G(d,p) level of theory, while a relaxed scan at the M06-2X/6-31g level of theory with 10° increments is used for the hindrance potential for low-frequency torsional modes. Single-point energies for all stationary points are obtained through the QCISD(T) and MP2 methods in combination with cc-pVDZ, cc-pVTZ, and cc-pVQZ basis sets, which can be extrapolated to the complete basis set (CBS) limit. The rate constants and branching ratios for isomerization and decomposition reactions are computed over a temperature range of 250-2000 K and a pressure range of 0.01-100 atm. Isomerization reactions are dominant at low temperatures, while decomposition reactions are more dominant at high temperatures. The branching ratio of the isomerization reaction exhibits a slight decrease with increasing pressure, while the trend for decomposition reactions depends on the type of the breaking bond. Based on the calculations for five branched pentanol radicals in part I, kinetics of linear and branched pentanol radicals are compared in this work and the results reveal that, for the same kind of β-scission reaction at similar positions of linear and branched pentanol radicals, the rate constants of branched ones are faster than those of linear ones at low temperatures. The hydroxyl group adjacent to the breaking bond can increase the β-scission reaction rate constants, while the effect can be ignored when the hydroxyl group is not adjacent to the breaking bond. Moreover, compared to when the hydroxyl group is located in the middle of the carbon chain, its positioning at the chain's end yields a more noticeable impact on the products and rate constants of C-O bond and O-H bond β-scission reactions. Besides, when incorporating calculated rate constants into the CRECK model, the updated mechanism shows a better performance for ignition delay times of 1-pentanol in the NTC range but exhibits lower reactivity at higher temperatures. The simulation of speciation profiles also shows better agreement with the experimental data obtained using a flow reactor.
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Affiliation(s)
- Yueying Liang
- Key Laboratory for Power Machinery and Engineering of M. O. E., Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
| | - Yuxiang Zhu
- School of Energy and Power Engineering, Beihang University, Beijing 100191, P. R. China
| | - Jintao Chen
- School of Energy and Power Engineering, Beihang University, Beijing 100191, P. R. China
| | - Xingcai Lu
- Key Laboratory for Power Machinery and Engineering of M. O. E., Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
| | - Chong-Wen Zhou
- School of Energy and Power Engineering, Beihang University, Beijing 100191, P. R. China
- Combustion Chemistry Centre, School of Biological and Chemical Sciences, University of Galway, Galway H91TK33, Ireland.
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Monge-Palacios M, Wang Q, Alshaarawi A, Sepulveda ACC, Sarathy SM. Quantum chemistry and kinetics of hydrogen sulphide oxidation. Phys Chem Chem Phys 2024; 26:3219-3228. [PMID: 38193631 DOI: 10.1039/d3cp04535h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
A fundamental understanding of the acid gas (H2S and CO2) chemistry is key to efficiently implement the desulphurisation process and even the production of clean fuels such as hydrogen or syngas. In this work, we developed a new kinetic model for the pyrolysis and oxidation of hydrogen sulphide by merging two previously reported models with the goal of covering a wider range of conditions and including the effect of carbon dioxide. The resulting model, which consists of 75 species and 514 reactions, was used to conduct rate of production and sensitivity analysis in plug flow reactor simulations, and the results were used to determine the most prominent reactions in which hydrogen sulphide, molecular hydrogen, and sulphur monoxide are involved. The resulting list of important reactions was screened and the kinetics of three of them, i.e., SO2 + S2 → S2O + SO, S2O + S2 → S3 + SO, and SO + SH → S2 + OH, was found to warrant further investigation. With the goal of improving the accurancy of our new kinetic model, we carried out a robust quantum chemistry and Rice-Ramsperger-Kassel-Marcus master equation study to obtain, for the first time, the forward and reverse rate constants for those three reactions at temperatures and pressures of interest for combustion and atmospheric chemistry. This work is the first step of a kinetic study that is aimed at improving the understanding of the chemistry of the pyrolysis and oxidation of H2S, highlighting the importance of sulphur-sulphur interactions and providing a fundamental basis for future kinetic models of H2S not only in the field of combustion, but also in atmospheric chemistry.
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Affiliation(s)
- M Monge-Palacios
- King Abdullah University of Science and Technology, Thuwal (Makkah) 23955, Saudi Arabia.
| | - Q Wang
- King Abdullah University of Science and Technology, Thuwal (Makkah) 23955, Saudi Arabia.
| | - A Alshaarawi
- Exploration and Petroleum Engineering Center-Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran 34465, Saudi Arabia
| | - A C Cavazos Sepulveda
- Exploration and Petroleum Engineering Center-Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran 34465, Saudi Arabia
| | - S M Sarathy
- King Abdullah University of Science and Technology, Thuwal (Makkah) 23955, Saudi Arabia.
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Zasimov PV, Volosatova AD, Góbi S, Keresztes B, Tyurin DA, Feldman VI, Tarczay G. Infrared spectroscopy of the α-hydroxyethyl radical isolated in cryogenic solid media. J Chem Phys 2024; 160:024308. [PMID: 38205854 DOI: 10.1063/5.0177189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
The α-hydroxyethyl radical (CH3·CHOH, 2A) is a key intermediate in ethanol biochemistry, combustion, atmospheric chemistry, radiation chemistry, and astrochemistry. Experimental data on the vibrational spectrum of this radical are crucially important for reliable detection and understanding of the chemical dynamics of this species. This study represents the first detailed experimental report on the infrared absorption bands of the α-hydroxyethyl radical complemented by ab initio computations. The radical was generated in solid para-H2 and Xe matrices via the reactions of hydrogen atoms with matrix-isolated ethanol molecules and radiolysis of isolated ethanol molecules with x rays. The absorption bands with maxima at 3654.6, 3052.1, 1425.7, 1247.9, 1195.6 (1177.4), and 1048.4 cm-1, observed in para-H2 matrices appearing upon the H· atom reaction, were attributed to the OHstr, α-CHstr, CCstr, COstr + CCObend, COstr, and CCstr + CCObend vibrational modes of the CH3·CHOH radical, respectively. The absorption bands with the positions slightly red-shifted from those observed in para-H2 were detected in both the irradiated and post-irradiation annealed Xe matrices containing C2H5OH. The results of the experiments with the isotopically substituted ethanol molecules (CH3CD2OH and CD3CD2OH) and the quantum-chemical computations at the UCCSD(T)/L2a_3 level support the assignment. The photolysis with ultraviolet light (240-300 nm) results in the decay of the α-hydroxyethyl radical, yielding acetaldehyde and its isomer, vinyl alcohol. A comparison of the experimental and theoretical results suggests that the radical adopts the thermodynamically more stable anti-conformation in both matrices.
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Affiliation(s)
- Pavel V Zasimov
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Anastasia D Volosatova
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sándor Góbi
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - Barbara Keresztes
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - Daniil A Tyurin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Vladimir I Feldman
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - György Tarczay
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Centre for Astrophysics and Space Science, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
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5
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Liang P, de Aragão EVF, Giani L, Mancini L, Pannacci G, Marchione D, Vanuzzo G, Faginas-Lago N, Rosi M, Skouteris D, Casavecchia P, Balucani N. OH( 2Π) + C 2H 4 Reaction: A Combined Crossed Molecular Beam and Theoretical Study. J Phys Chem A 2023. [PMID: 37207281 DOI: 10.1021/acs.jpca.2c08662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The reaction between the ground-state hydroxyl radical, OH(2Π), and ethylene, C2H4, has been investigated under single-collision conditions by the crossed molecular beam scattering technique with mass-spectrometric detection and time-of-flight analysis at the collision energy of 50.4 kJ/mol. Electronic structure calculations of the underlying potential energy surface (PES) and statistical Rice-Ramsperger-Kassel-Marcus (RRKM) calculations of product branching fractions on the derived PES for the addition pathway have been performed. The theoretical results indicate a temperature-dependent competition between the anti-/syn-CH2CHOH (vinyl alcohol) + H, CH3CHO (acetaldehyde) + H, and H2CO (formaldehyde) + CH3 product channels. The yield of the H-abstraction channel could not be quantified with the employed methods. The RRKM results predict that under our experimental conditions, the anti- and syn-CH2CHOH + H product channels account for 38% (in similar amounts) of the addition mechanism yield, the H2CO + CH3 channel for ∼58%, while the CH3CHO + H channel is formed in negligible amount (<4%). The implications for combustion and astrochemical environments are discussed.
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Affiliation(s)
- Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Emília Valença Ferreira de Aragão
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Master-Tec Srl, Via Sicilia, 41, Perugia 06128, Italy
| | - Lisa Giani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Université Grenoble Alpes, 621 Av. Centrale, Saint-Martin-d'Hères 38400, France
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Noelia Faginas-Lago
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Master-Tec Srl, Via Sicilia, 41, Perugia 06128, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile Ed Ambientale, Università Degli Studi di Perugia, Perugia 06125, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
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Smith Lewin C, Herbinet O, Battin-Leclerc F, Bourgalais J. Ozone-assisted oxidation of ethylene in a jet-stirred reactor: An experimental and modeling study. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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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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8
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Mohamed SY, Monge-Palacios M, Giri BR, Khaled F, Liu D, Farooq A, Sarathy SM. The Effect of Hydrogen Bonding on the Reactivity of OH Radicals with Prenol and Isoprenol: A Shock Tube and Multi-Structural Torsional Variational Transition State Theory Study. Phys Chem Chem Phys 2022; 24:12601-12620. [DOI: 10.1039/d2cp00737a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The presence of two functional groups (OH and double bond) in C5 methyl-substituted enols (i.e., isopentenols), such as 3-methyl-2-buten-1-ol (prenol) and 3-methyl-3-buten-1-ol (isoprenol), makes them excellent biofuel candidates as fuel...
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9
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Dash MR, Akbar Ali M. Effect of a single water molecule on ˙CH 2OH + 3O 2 reaction under atmospheric and combustion conditions. Phys Chem Chem Phys 2021; 24:1510-1519. [PMID: 34935796 DOI: 10.1039/d1cp03911c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The hydroxymethyl (˙CH2OH) radical is an important intermediate species in both atmosphere and combustion reaction systems. The rate coefficients for ˙CH2OH + 3O2 and (˙CH2OH + 3O2 (+H2O)) reactions were calculated using the Rice-Ramsperger-Kassel-Marcus (RRKM)/master equation (ME) simulation and canonical variational transition state theory (CVT) between the temperature range of 200 to 1500 K based on the potential energy surface constructed using CCSD(T)//ωB97XD/6-311++G(3df,3pd). The results show that ˙CH2OH + 3O2 leads to the formation of CH2O and HO2 at temperatures below 800 K, and goes back to reactants at high temperature (>1000 K). When a water molecule is added to the reaction, the formation of CH2O and HO2 is favored at all temperatures. The calculated rate coefficient for the ˙CH2OH + 3O2 (2.8 × 10-11 cm3 molecule-1 s-1 at 298 K) is in good agreement with the previous experimental values (∼1 × 10-11 cm3 molecule-1 s-1 at 298 K). The rate coefficients for the water-assisted reaction (2.4 × 10-16 cm3 molecule-1 s-1 at 1000 K) is at least 3-4 orders of magnitude smaller than the water-free reaction (6.2 × 10-12 cm3 molecule-1 s-1 at 1000 K). This result is consistent with the similar types of reaction system. Our calculations also predict that the effect of a single water molecule favors the formation of CH2O in the combustion condition. However, the water-free reaction favors the formation of CH2O in the atmospheric condition. The current study helps to understand how a single water molecule changes the reaction mechanism and chemical kinetic behaviour under atmospheric and combustion conditions.
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Affiliation(s)
- Manas Ranjan Dash
- Department of Chemistry, National Institute of Technology, Raipur 492010, India
| | - Mohamad Akbar Ali
- Department of Chemistry, College of Science, King Faisal University, P.O. Box 380, Al Hufuf 31982, Al-Ahsa, Saudi Arabia.
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Blitz MA, Pilling MJ, Robertson SH, Seakins PW, Speak TH. Global Master Equation Analysis of Rate Data for the Reaction C 2H 4 + H ⇄ C 2H 5: Δ fH0⊖C 2H 5. J Phys Chem A 2021; 125:9548-9565. [PMID: 34704447 DOI: 10.1021/acs.jpca.1c05911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While forward and reverse rate constants are frequently used to determine enthalpies of reaction and formation, this process is more difficult for pressure-dependent association/dissociation reactions, especially since the forward and reverse reactions are usually studied at very different temperatures. The problems can be overcome by using a data-fitting procedure based on a master equation model. This approach has been applied to existing experimental pressure-dependent forward and reverse rate coefficients for the reaction C2H4 + H ⇄ C2H5 (k1, k-1) using the MESMER code to determine ΔfH0⊖C2H5 from the enthalpy of the reaction. New measurements of k1, k-1 were included in analysis. They are based on laser flash photolysis with direct observation of H atom time profiles by vacuum ultraviolet laser-induced fluorescence under conditions where the approach to equilibrium could be observed. Measurements were made over the temperature range 798-828 K and with [He] from 2.33 to 7.21 × 1018 molecule cm-3. These data were then combined with a wide range of existing experimental data with helium as the bath gas (112 measurements of k1 and k-1, covering the temperature range 285-1094 K, and [He] = 7.1 × 1015-1.9 × 1019 molecule cm-3) and fitted using the master equation solver MESMER. The required vibrational frequencies and rotational constants of the system were obtained from ab initio calculations, and the activation threshold for association (ΔEthresh), enthalpy of reaction (ΔrH0⊖), imaginary frequency (υimag), and helium energy-transfer parameters (⟨ΔE⟩d,298(T/298)n) were optimized. The resulting parameters (errors are 2σ) are ΔEthresh = 11.43 ± 0.34 kJ mol-1, ΔrH0⊖ = -145.34 ± 0.60 kJ mol-1, υimag = 730 ± 130 cm-1, ⟨ΔE⟩d,298 = 54.2 ± 7.6 cm-1, and n = 1.17 ± 0.12. A value of ΔfH298.15⊖(C2H5) = 120.49 ± 0.57 kJ mol-1 is obtained by combining ΔrH0⊖ with standard enthalpies of formation for H and C2H4 and making the appropriate temperature corrections. The dependence of these parameters on how the internal rotor and CH2 inversion modes are treated has been explored. The experimental data for other bath gases have been analyzed, and data sets compatible with the potential energy surface parameters determined above have been identified. The parameters are virtually identical but with slightly smaller error limits. Parameterization of k1, k-1 using the Troe formalization has been used to investigate competition between ethyl decomposition and reaction with oxygen under combustion conditions.
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Affiliation(s)
- Mark A Blitz
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K.,National Centre for Atmospheric Science (NCAS), University of Leeds, Leeds LS2 9JT, U.K
| | | | | | - Paul W Seakins
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Thomas H Speak
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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11
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El Othmani H, Ren Y, Mellouki A, Daële V, McGillen MR. Gas-phase rate coefficient of OH + cyclohexene oxide measured from 251 to 373 K. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.139056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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Williams AE, Hammer NI, Tschumper GS. Relative energetics of CH 3CH 2O, CH 3CHOH, and CH 2CH 2OH radical products from ethanol dehydrogenation. J Chem Phys 2021; 155:114306. [PMID: 34551536 DOI: 10.1063/5.0062809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This study has examined the relative energetics of nine stationary points associated with the three different radical isomers generated by removing a H atom from ethanol at the O atom (ethoxy, CH3CH2O), the α C atom (CH3CHOH), and the β C atom (CH2CH2OH). For the first time, CCSD(T) geometry optimizations and harmonic vibrational frequency computations with the cc-pVTZ and aug-cc-pVTZ basis sets have been carried out to characterize two unique minima for each isomer along with three transition state structures with Cs symmetry. Explicitly correlated CCSD(T) computations were also performed to estimate the relative energetics of these nine stationary points near the complete basis set limit. These benchmark results were used to assess the performance of various density functional theory (DFT) and wave function theory methods, and they will help guide method selection for future studies of alcohols and their radicals. The structures generated by abstracting H from the α C atom have significantly lower electronic energies (by at least 7 kcal mol-1) than the CH3CH2O and CH2CH2OH radicals. Although previously reported as a minimum on the ground-state surface, the 2A″ Cs structure of the ethoxy radical was found to be a transition state in this study with MP2, CCSD(T), and a number of DFT methods. An implicit solvation model used in conjunction with DFT and MP2 methods did not qualitatively change the relative energies of the isomers, but the results suggest that the local minima for the CH3CHOH and CH2CH2OH radicals could become more energetically competitive in condensed phase environments, such as liquid water and ethanol.
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Affiliation(s)
- Ashley E Williams
- Department of Chemistry and Biochemistry, University of Mississippi, P.O. Box 1848, University, Mississippi 38677, USA
| | - Nathan I Hammer
- Department of Chemistry and Biochemistry, University of Mississippi, P.O. Box 1848, University, Mississippi 38677, USA
| | - Gregory S Tschumper
- Department of Chemistry and Biochemistry, University of Mississippi, P.O. Box 1848, University, Mississippi 38677, USA
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13
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Benitez Y, Parsons AJ, Lunny KG, Continetti RE. Dissociative Photodetachment Dynamics of the OH -(C 2H 4) Anion Complex. J Phys Chem A 2021; 125:4540-4547. [PMID: 34030440 DOI: 10.1021/acs.jpca.1c01835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoelectron-photofragment coincidence (PPC) measurements on OH-(C2H4) anions at a photon energy of 3.20 eV revealed stable and dissociative photodetachment product channels, OH-C2H4 + e- and OH + C2H4 + e-, respectively. The main product channel observed was dissociation to the reactants (>67%), OH + C2H4 (v = 0, 1, 2) + e-, where vibrational excitation in the C-H stretching modes of the C2H4 photofragments corresponds to a minor channel. The low kinetic energy release (KER) of the dissociating fragments is consistent with weak repulsion between the OH + C2H4 reactants near the transition state as well as the partitioning of energy into rotation of the dissociation products. An impulsive model was used to account for rotational energy partitioning in the dissociative photodetachment (DPD) process and showed good agreement with the experimental results. The low KER of the dissociating fragments and the similarities in the photoelectron spectra between stable and dissociative events support a mechanism involving the van der Waals complex formed upon photodetachment of OH-(C2H4) as an intermediate in the dominant OH + C2H4 + e- dissociative channel.
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Affiliation(s)
- Yanice Benitez
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Austin J Parsons
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Katharine G Lunny
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Robert E Continetti
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
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14
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Grajales-González E, Monge-Palacios M, Sarathy SM. Collision Efficiency Parameter Influence on Pressure-Dependent Rate Constant Calculations Using the SS-QRRK Theory. J Phys Chem A 2020; 124:6277-6286. [PMID: 32663402 PMCID: PMC7458424 DOI: 10.1021/acs.jpca.0c02943] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The system-specific quantum Rice-Ramsperger-Kassel (SS-QRRK) theory (J. Am. Chem. Soc. 2016, 138, 2690) is suitable to determine rate constants below the high-pressure limit. Its current implementation allows incorporating variational effects, multidimensional tunneling, and multistructural torsional anharmonicity in rate constant calculations. Master equation solvers offer a more rigorous approach to compute pressure-dependent rate constants, but several implementations available in the literature do not incorporate the aforementioned effects. However, the SS-QRRK theory coupled with a formulation of the modified strong collision model underestimates the value of unimolecular pressure-dependent rate constants in the high-temperature regime for reactions involving large molecules. This underestimation is a consequence of the definition for collision efficiency, which is part of the energy transfer model. Selection of the energy transfer model and its parameters constitutes a common issue in pressure-dependent calculations. To overcome this underestimation problem, we evaluated and implemented in a bespoke Python code two alternative definitions for the collision efficiency using the SS-QRRK theory and tested their performance by comparing the pressure-dependent rate constants with the Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) results. The modeled systems were the tautomerization of propen-2-ol and the decomposition of 1-propyl, 1-butyl, and 1-pentyl radicals. One of the tested definitions, which Dean et al. explicitly derived (Z. Phys. Chem. 2000, 214, 1533), corrected the underestimation of the pressure-dependent rate constants and, in addition, qualitatively reproduced the trend of RRKM/ME data. Therefore, the used SS-QRRK theory with accurate definitions for the collision efficiency can yield results that are in agreement with those from more sophisticated methodologies such as RRKM/ME.
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Affiliation(s)
- E Grajales-González
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
| | - M Monge-Palacios
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
| | - S Mani Sarathy
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
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15
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Updating radical ring-opening polymerisation of cyclic ketene acetals from synthesis to degradation. Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2020.109851] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Medeiros DJ, Robertson SH, Blitz MA, Seakins PW. Direct Trace Fitting of Experimental Data Using the Master Equation: Testing Theory and Experiments on the OH + C 2H 4 Reaction. J Phys Chem A 2020; 124:4015-4024. [PMID: 32353235 DOI: 10.1021/acs.jpca.0c02132] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Laser flash photolysis coupled with laser-induced fluorescence observation of OH has been used to observe the equilibration of OH + C2H4 ↔ HOC2H4 over the temperature range 563-723 K and pressures of bath gas (N2) from 58 to 250 Torr. The time-resolved OH traces have been directly and globally fitted with a master equation in order to extract ΔRH00, the binding energy of the HOC2H4 adduct, with respect to reagents. The global approach allows the role that OH abstraction plays at higher temperatures to be identified. The resultant value ofΔRH00, 111.8 kJ mol-1, is determined to be better than 2 kJ mol-1 and is in agreement with our ab initio calculations (carried out at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level), 111.4 kJ mol-1, and other state of the art calculations. Parameters for the abstraction channel are also in good agreement with previous experimental studies. To effect this analysis, the MESMER master equation code was extended to directly incorporate secondary chemistry: diffusional loss from the observation region and reaction with the photolytic precursor. These extensions, which, among other things, resolve issues related to the merging of chemically significant and internal energy relaxation eigenvalues, are presented.
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Affiliation(s)
| | - S H Robertson
- Dassault Systèmes, 334 Science Park, Milton Road, Cambridge CB4 0WN, United Kingdom
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17
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Monge-Palacios M, Grajales-González E, Kukkadapu G, Sarathy SM. Kinetics of the benzyl + HO 2 and benzoxyl + OH barrierless association reactions: fate of the benzyl hydroperoxide adduct under combustion and atmospheric conditions. Phys Chem Chem Phys 2020; 22:9029-9039. [PMID: 32293625 DOI: 10.1039/d0cp00752h] [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
Radical-radical association reactions are challenging to address theoretically due to difficulties finding the bottleneck that variationally minimizes the reactive flux. For this purpose, the variable reaction coordinate (VRC) formulation of the variational transition state theory (VTST) represents an appropriate tool. In this work, we revisited the kinetics of two radical-radical association reactions of importance in combustion modelling and poly-aromatic hydrocarbon (PAH) chemistry by performing VRC calculations: benzyl + HO2 and benzoxyl + OH, both forming the adduct benzyl hydroperoxide. Our calculated rate constants are significantly lower than those previously reported based on VTST calculations, which results from a more efficient minimization of the reactive flux through the bottleneck achieved by the VRC formulation. Both reactions show different trends in the variation of their rate constants with temperature. We observed that if the pair of single occupied molecular orbitals (SOMOs) of the associating radicals show a similar nature, i.e. similar character, and thereby a small energy gap, a highly stabilized transition state structure is formed as the result of a very efficient SOMO-SOMO overlap, which may cancel out the free energy bottleneck for the formation of the adduct and result in large rate constants with a negative temperature dependence. This is the case of the benzoxyl and OH radical pair, whose SOMOs show O2p nature with an energy gap of 20.2 kcal mol-1. On the other hand, the benzyl and HO2 radical pair shows lower rate constants with a positive temperature dependence due to the larger difference between both SOMOs (a 28.9 kcal mol-1 energy gap) as a consequence of the contribution of the multiple resonance structures of the benzyl radical. The reverse dissociation rate constants were also calculated using multi-structural torsional anharmonicity partition functions, which were not included in previous work, and the results show a much slower dissociation of benzyl hydroperoxide. Our work may help to improve kinetic models of interest in combustion and PAH formation, as well as to gain further understanding of radical-radical association reactions, which are ubiquitous in different environments.
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Affiliation(s)
- M Monge-Palacios
- King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE), Thuwal 23955-6900, Saudi Arabia.
| | - Edwing Grajales-González
- King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE), Thuwal 23955-6900, Saudi Arabia.
| | - Goutham Kukkadapu
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551, USA
| | - S Mani Sarathy
- King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE), Thuwal 23955-6900, Saudi Arabia.
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18
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Chin CH, Zhu T, Zhang JZH. Reaction mechanism and product branching ratios of OH+C 2H 3F reaction: A theoretical study. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2001016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Chih-Hao Chin
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - Tong Zhu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - John Zeng-Hui Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
- Department of Chemistry, New York University, New York 10003, United States of America
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19
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de Souza Machado G, Martins EM, Baptista L, Bauerfeldt GF. Prediction of Rate Coefficients for the H 2CO + OH → HCO + H 2O Reaction at Combustion, Atmospheric and Interstellar Medium Conditions. J Phys Chem A 2020; 124:2309-2317. [PMID: 32091904 DOI: 10.1021/acs.jpca.9b11690] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite the relevance of the H2CO + OH → HCO + H2O reaction for combustion, atmospheric, and interstellar medium conditions, a large discrepancy on energetic and kinetic data for this reaction is still observed in the previous literature. In this work, this hydrogen abstraction reaction has been investigated at the CCSD(T)/CBS level of theory, suggesting that both the prebarrier complex and saddle point are stabilized in relation to the reactants by 3.31 and 1.35 kcal mol-1, respectively. Moreover, from the Gibbs free energy profile of the reaction coordinate, it has been verified that the formation of the prebarrier complex is endergonic, for temperatures above 550 K. Hence, for temperatures lower than 550 K, the reaction is described by a mechanism consisting of three elementary steps, while for higher temperatures it can be assumed to be an elementary reaction. Finally, the prediction of rate coefficients suggests that unified statistical rate theory best applies to the low temperature regime, while canonical variational rate coefficients better fit experimental data at the high temperature regime.
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Affiliation(s)
- Gladson de Souza Machado
- Instituto de Quı́mica, Universidade Federal Rural do Rio de Janeiro, BR-465 km 7, Seropédica, RJ, 23890-000 Brazil
| | - Eduardo Monteiro Martins
- Departamento de Engenharia Sanitária e do Meio Ambiente, Faculdade de Engenharia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, 20550-900 Brazil
| | - Leonardo Baptista
- Departamento de Quı́mica e Ambiental, Faculdade de Tecnologia, Universidade do Estado do Rio de Janeiro, Rodovia Presidente Dutra km 298, Resende, RJ, 27537-000 Brazil
| | - Glauco F Bauerfeldt
- Instituto de Quı́mica, Universidade Federal Rural do Rio de Janeiro, BR-465 km 7, Seropédica, RJ, 23890-000 Brazil
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20
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Chao W, Yin C, Takahashi K, Lin JJM. Hydrogen-Bonding Mediated Reactions of Criegee Intermediates in the Gas Phase: Competition between Bimolecular and Termolecular Reactions and the Catalytic Role of Water. J Phys Chem A 2019; 123:8336-8348. [DOI: 10.1021/acs.jpca.9b07117] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wen Chao
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Cangtao Yin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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21
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Mai TVT, Huynh LK. Ab initio kinetics of the C 2H 2 + NH 2 reaction: a revisited study. Phys Chem Chem Phys 2019; 21:17232-17239. [PMID: 31347629 DOI: 10.1039/c9cp02258a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work provides a rigorous detailed kinetic study on the C2H2 + NH2 reaction in a wide range of conditions (T = 250-2000 K & P = 1-76000 Torr). In particular, the composite method W1U was used to construct the potential energy surface on which the kinetic behaviors were characterized within the state-of-the-art master equation/Rice-Ramsperger-Kassel-Marcus (ME/RRKM) framework. Corrections of the hindered internal rotation (HIR) treatment and quantum tunneling effect were included. A clear reaction mechanism shift with respect to both temperature and pressure was revealed via detailed kinetic and species analyses. In particular, bimolecular products (i.e., CH2[double bond, length as m-dash]C[double bond, length as m-dash]NH + H, CH[triple bond, length as m-dash]CNH2 + H, CH3CN + H, CH[triple bond, length as m-dash]C· + NH3 in the decreasing mole fraction order) can be formed directly from the reactants at high temperature and/or low pressure while they can be produced indirectly via intermediates (e.g., ·CH[double bond, length as m-dash]CHNH2(cis), ·CH[double bond, length as m-dash]CHNH2(trans), CH2[double bond, length as m-dash]C·NH2,…) at low temperature and/or high pressure. The calculated rate constants are in good agreement with the literature data from ab initio calculations without any adjustment; thus, the proposed temperature- and pressure-dependent rate constants, together with the thermodynamic data of the species involved, can be confidently used for modeling NH2-related systems under atmospheric and combustion conditions.
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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. and University of Science, Vietnam National University - HCMC, 227 Nguyen Van Cu, Ward 4, District 5, Ho Chi Minh City, Vietnam
| | - Lam K Huynh
- International University, Vietnam National University - HCMC, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam.
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22
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Sela P, Sakai Y, Choi HS, Herzler J, Fikri M, Schulz C, Peukert S. High-Temperature Unimolecular Decomposition of Diethyl Ether: Shock-Tube and Theory Studies. J Phys Chem A 2019; 123:6813-6827. [PMID: 31329437 DOI: 10.1021/acs.jpca.9b04186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The unimolecular decomposition of diethyl ether (DEE; C2H5OC2H5) is considered to be initiated via a molecular elimination and a C-O and a C-C bond fission step: C2H5OC2H5 → C2H4 + C2H5OH (1), C2H5OC2H5 → C2H5 + C2H5O (2), and C2H5OC2H5 → CH3 + C2H5OCH2 (3). In this work, two shock-tube facilities were used to investigate these reactions via (a) time-resolved H-atom concentration measurements by H-ARAS (atomic resonance absorption spectrometry), (b) time-resolved DEE-concentration measurements by high repetition-rate time-of-flight mass spectrometry (HRR-TOF-MS), and (c) product-composition measurements via gas chromatography/MS (GC/MS) after quenching the test gas. The experiments were conducted at temperatures ranging from 1054 to 1505 K and at pressures between 1.2 and 2.5 bar. Initial DEE mole fractions between 0.4 and 9300 ppm were used to perform the kinetics experiments by H-ARAS (0.4 ppm), GC/MS (200-500 ppm), and HRR-TOF-MS (7850-9300 ppm). The rate constants, ktotal (ktotal = k1 + k2 + k3) derived from the GC/MS and HRR-TOF-MS experiments agree well with each other and can be described by the Arrhenius expression, ktotal(1054-1467 K; 1.3-2.5 bar) = 1012.81±0.22 exp(-240.27 ± 5.11 kJ mol-1/RT) s-1. From the H-ARAS experiments, overall rate constants for the bond fission channels, k2+3 = k2 + k3 have been extracted. The k2+3 data can be well described by the Arrhenius equation, k2+3(1299-1505 K; 1.3-2.5 bar) = 1014.43±0.33 exp(-283.27 ± 8.78 kJ mol-1/RT) s-1. A master-equation analysis was performed using CCSD(T)/aug-cc-pvtz//B3LYP/aug-cc-pvtz and CASPT2/aug-cc-pvtz//B3LYP/aug-cc-pvtz molecular properties and energies for the three primary thermal decomposition processes in DEE. The derived experimental data is very well reproduced by the simulations with the mechanism of this work. With regard to the branching ratios between bond fissions and elimination channels, uncertainties remain.
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Affiliation(s)
- Paul Sela
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
| | - Yasuyuki Sakai
- Graduate School of Engineering , University of Fukui , Fukui 910-8507 , Japan
| | - Hang Seok Choi
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
| | - Jürgen Herzler
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
| | - Mustapha Fikri
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
| | - Christof Schulz
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
| | - Sebastian Peukert
- IVG, Institute for Combustion and Gas Dynamics-Reactive Fluids and CENIDE, Center for Nanointegration Duisburg-Essen , University of Duisburg-Essen , 47048 Duisburg , Germany
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23
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Lockhart JPA, Gross EC, Sears TJ, Hall GE. Kinetic study of the OH + ethylene reaction using frequency‐modulated laser absorption spectroscopy. INT J CHEM KINET 2019. [DOI: 10.1002/kin.21265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Eisen C. Gross
- Department of ChemistryStony Brook University Stony Brook New York
| | - Trevor J. Sears
- Division of Chemistry, Brookhaven National Laboratory Upton New York
- Department of ChemistryStony Brook University Stony Brook New York
| | - Gregory E. Hall
- Division of Chemistry, Brookhaven National Laboratory Upton New York
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24
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Xu B, Garrec J, Nicolle A, Matrat M, Catoire L. Temperature and Pressure Dependent Rate Coefficients for the Reaction of Ketene with Hydroxyl Radical. J Phys Chem A 2019; 123:2483-2496. [PMID: 30852895 DOI: 10.1021/acs.jpca.8b11273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of ketene with hydroxyl radical is drawing growing attention, for it is found to constitute an important step during the combustion of hydrocarbon and oxygenated hydrocarbon fuels, e.g., acetylene, propyne, allene, acetone, gasoline, diesel, jet fuels, and biofuels. We studied the potential energy surface (PES) of this reaction using B2PLYP-D3/cc-PVTZ for geometry optimization and composite methods based on CCSD(T)-F12/cc-PVTZ-F12 for energy calculations. From this PES, temperature- and pressure-dependent rate coefficients and branching ratios at 200-3000 K and 0.01-100 atm were derived using the RRKM/ME approach. The reaction is dominated by four product channels: (i) OH addition on the olefinic carbon of ketene to form CH2OH + CO, which is the most dominant under all conditions; (ii) H abstraction producing HCCO + H2O, which is favored at high temperatures; (iii) OH addition on the carbonyl carbon to form CH3 + CO2, which is favored at low pressures and high temperatures; and (iv) collisional stabilization of CH2COOH, which is favored at high pressures and low temperatures. With increasing temperatures, the overall rate constant koverall exhibit first negative but then positive temperature dependency, with its switching point (also the minimum point) at ∼400 K. Both product channel CH2OH + CO and HCCO + H2O are independent of pressure, whereas formation of CH3 + CO2 and collisional stabilization of CH2COOH are highly pressure dependent. Fitted modified Arrhenius expressions of the calculated rate constants are provided for the purpose of combustion modeling.
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Affiliation(s)
- Boyang Xu
- Unité Chimie et Procédés (UCP) , ENSTA ParisTech , 828 Boulevard des Maréchaux , 91120 Palaiseau , France
| | - Julian Garrec
- Unité Chimie et Procédés (UCP) , ENSTA ParisTech , 828 Boulevard des Maréchaux , 91120 Palaiseau , France
| | - André Nicolle
- Unité Chimie et Procédés (UCP) , ENSTA ParisTech , 828 Boulevard des Maréchaux , 91120 Palaiseau , France
| | - Mickaël Matrat
- IFP Energies nouvelles (IFPEN) , 1 et 4 avenue de Bois-Préau , 92852 Rueil-Malmaison , France
| | - Laurent Catoire
- Unité Chimie et Procédés (UCP) , ENSTA ParisTech , 828 Boulevard des Maréchaux , 91120 Palaiseau , France
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25
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Chao W, Yin C, Takahashi K, Lin JJM. Effects of water vapor on the reaction of CH2OO with NH3. Phys Chem Chem Phys 2019; 21:22589-22597. [DOI: 10.1039/c9cp04682h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A strong synergic effect of water and ammonia molecules may enhance the formation of H2NCH2OOH.
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Affiliation(s)
- Wen Chao
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Cangtao Yin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Chemistry
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26
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Chu H, Wu W, Shao Y, Tang Y, Zhang Y, Cheng Y, Chen F, Liu J, Sun J. A quantum theory investigation on atmospheric oxidation mechanisms of acrylic acid by OH radical and its implication for atmospheric chemistry. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:24939-24950. [PMID: 29931646 DOI: 10.1007/s11356-018-2561-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/13/2018] [Indexed: 06/08/2023]
Abstract
The hydroxyl radical, as the most important oxidant, controls the removal of some volatile organic compounds (VOCs) in the atmosphere. In this work, the atmospheric oxidation processes of acrylic acid by OH radical have been investigated by density functional theory (DFT). The energetic routes of the reaction of CH2CHCOOH with OH radical have been calculated accurately at the CCSD(T)/cc-pVTZ//M06-2X/6-311++G(d,p) level. It is implicated that the oxidation has five elementary reaction pathways mostly hinging on how hydroxyl radical approaches to the carbon skeleton of acrylic acid. The atmospheric degradation mechanisms of the CH2CHCOOH by OH radical are the formation of reactive intermediates IM1 and IM2. Meanwhile, the further oxidation mechanisms of IM1 and IM2 by O3 and NO are also investigated. The rate coefficients have been computed using tight transition state theory of the variflex code. The calculated rate coefficient is 2.3 × 10-11 cm3 molecule-1 s-1 at standard pressure and 298 K, which is very close to the laboratory data (1.75 ± 0.47 × 10-11 cm3 molecule-1 s-1). Moreover, the atmospheric lifetime of acrylic acid is about 6 h at 298 K and 1 atm, implying that the fast sinks of acrylic acid by hydroxyl radical.
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Affiliation(s)
- Han Chu
- Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China
| | - Wenzhong Wu
- College of Foreign Languages, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China
| | - Youxiang Shao
- School of Materials Science and Engineering, MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Yizhen Tang
- School of Environmental and municipal Engineering, Qingdao Technological University, Fushun Road 11, Qingdao, Shandong, 266033, People's Republic of China
| | - Yunju Zhang
- Key Laboratory of Photoinduced Functional Materials, Mianyang Normal University, Mianyang, 621000, People's Republic of China
| | - Yinfang Cheng
- Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China
| | - Fang Chen
- Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China
| | - Jiangyan Liu
- Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China
| | - Jingyu Sun
- Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, People's Republic of China.
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27
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Grajales-González E, Monge-Palacios M, Sarathy SM. Theoretical Kinetic Study of the Unimolecular Keto–Enol Tautomerism Propen-2-ol ↔ Acetone. Pressure Effects and Implications in the Pyrolysis of tert- and 2-Butanol. J Phys Chem A 2018; 122:3547-3555. [DOI: 10.1021/acs.jpca.8b00836] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E. Grajales-González
- Clean Combustion Research Center, King Abdullah University of Science and Technology, Al Kindi Building 5, Thuwal 23955, Saudi Arabia
| | - M. Monge-Palacios
- Clean Combustion Research Center, King Abdullah University of Science and Technology, Al Kindi Building 5, Thuwal 23955, Saudi Arabia
| | - S. Mani Sarathy
- Clean Combustion Research Center, King Abdullah University of Science and Technology, Al Kindi Building 5, Thuwal 23955, Saudi Arabia
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28
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Yin G, Hu E, Gao Z, Yang F, Huang Z. Kinetics of H abstraction and addition reactions of 2,4,4-trimethyl-2-pentene by OH radical. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.02.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Jiao Y, Dibble TS. First kinetic study of the atmospherically important reactions BrHg˙ + NO 2 and BrHg˙ + HOO. Phys Chem Chem Phys 2018; 19:1826-1838. [PMID: 28000816 DOI: 10.1039/c6cp06276h] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We use computational chemistry to determine the rate constants and product yields for the reactions of BrHg˙ with the atmospherically abundant radicals NO2 and HOO. The reactants, products, and well-defined transition states are characterized using CCSD(T) with large basis sets. The potential energy profiles for the barrierless addition of HOO and NO2 to BrHg˙ are characterized using CASPT2 and RHF-CCSDT, and the rate constants are computed as a function of temperature and pressure using variational transition state theory and master equation simulations. The calculated rate constant for the addition of NO2 to BrHg˙ is larger than that for the addition of HOO by a factor of up to two under atmospheric conditions. For the reaction of HOO with BrHg˙ the addition reaction entirely dominates competing HOO + BrHg˙ reaction channels. The addition of NO2 to BrHg˙ initially produces both BrHgNO2 and BrHgONO, but after a few seconds under atmospheric conditions the sole product is syn-BrHgONO. A previously unsuspected reaction channel for BrHg˙ + NO2 competes with the addition to yield Hg + BrNO2. This reaction reduces the mercury oxidation state in BrHg˙ from Hg(i) to Hg(0) and slows the atmospheric oxidation of Hg(0). While the rate constant for this reduction channel is not well-constrained by the present calculations, it may be as much as 18% as large as the oxidation channel under some atmospheric conditions. As no experimental kinetic or product yield data are available for the reactions studied here, this work will provide guidance for atmospheric modelers and experimental kineticists.
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Affiliation(s)
- Yuge Jiao
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, 1 Forestry Dr, Syracuse, NY 13210, USA.
| | - Theodore S Dibble
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, 1 Forestry Dr, Syracuse, NY 13210, USA.
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30
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Shannon R, Glowacki DR. A Simple “Boxed Molecular Kinetics” Approach To Accelerate Rare Events in the Stochastic Kinetic Master Equation. J Phys Chem A 2018; 122:1531-1541. [DOI: 10.1021/acs.jpca.7b12521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Robin Shannon
- Mechanical Engineering, Stanford University, Stanford, California 94305, United States
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom
| | - David R. Glowacki
- Mechanical Engineering, Stanford University, Stanford, California 94305, United States
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom
- Department of Computer Science, University of Bristol, Bristol, BS8 1UB, United Kingdom
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31
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Song B, Lo AY, Wang J. Theoretical study of olefin protonation reactions confined inside mordenite zeolite by energy decomposition analysis. MOLECULAR CATALYSIS 2017. [DOI: 10.1016/j.mcat.2017.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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32
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Kovacevic G, Sabljic A. Atmospheric oxidation of halogenated aromatics: comparative analysis of reaction mechanisms and reaction kinetics. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:357-369. [PMID: 28002503 DOI: 10.1039/c6em00577b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atmospheric transport is the major route for global distribution of semi-volatile compounds such as halogenated aromatics as well as their major exposure route for humans. Their major atmospheric removal process is oxidation by hydroxyl radicals. There is very little information on the reaction mechanism or reaction-path dynamics of atmospheric degradation of halogenated benzenes. Furthermore, the measured reaction rate constants are missing for the range of environmentally relevant temperatures, i.e. 230-330 K. A series of recent theoretical studies have provided those valuable missing information for fluorobenzene, chlorobenzene, hexafluorobenzene and hexachlorobenzene. Their comparative analysis has provided additional and more general insight into the mechanism of those important tropospheric degradation processes as well as into the mobility, transport and atmospheric fate of halogenated aromatic systems. It was demonstrated for the first time that the addition of hydroxyl radicals to monohalogenated as well as to perhalogenated benzenes proceeds indirectly, via a prereaction complex and its formation and dynamics have been characterized including the respective transition-state. However, in fluorobenzene and chlorobenzene reactions hydroxyl radical hydrogen is pointing approximately to the center of the aromatic ring while in the case of hexafluorobenzene and hexachlorobenzene, unexpectedly, the oxygen is directed towards the center of the aromatic ring. The reliable rate constants are now available for all environmentally relevant temperatures for the tropospheric oxidation of fluorobenzene, chlorobenzene, hexafluorobenzene and hexachlorobenzene while pentachlorophenol, a well-known organic micropollutant, seems to be a major stable product of tropospheric oxidation of hexachlorobenzene. Their calculated tropospheric lifetimes show that fluorobenzene and chlorobenzene are easily removed from the atmosphere and do not have long-range transport potential while hexafluorobenzene seems to be a potential POP chemical and hexachlorobenzene is clearly a typical persistent organic pollutant.
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Affiliation(s)
- Goran Kovacevic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Republic of Croatia.
| | - Aleksandar Sabljic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Republic of Croatia.
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33
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Degirmenci I, Coote ML. UNDERSTANDING THE BEHAVIOUR OF SULPHUR-CENTRED RADICALS DURING POLYMER SELF-HEALING. JOURNAL OF THE TURKISH CHEMICAL SOCIETY, SECTION A: CHEMISTRY 2016. [DOI: 10.18596/jotcsa.287305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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34
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Olm C, Varga T, Valkó É, Hartl S, Hasse C, Turányi T. Development of an Ethanol Combustion Mechanism Based on a Hierarchical Optimization Approach. INT J CHEM KINET 2016. [DOI: 10.1002/kin.20998] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Carsten Olm
- Institute of Chemistry; Eötvös University (ELTE); Budapest Hungary
- MTA-ELTE Research Group on Complex Chemical Systems; Budapest Hungary
- Numerical Thermo-Fluid Dynamics; TU Bergakademie, Freiberg; Germany
| | - Tamás Varga
- Institute of Chemistry; Eötvös University (ELTE); Budapest Hungary
- MTA-ELTE Research Group on Complex Chemical Systems; Budapest Hungary
| | - Éva Valkó
- Institute of Chemistry; Eötvös University (ELTE); Budapest Hungary
- MTA-ELTE Research Group on Complex Chemical Systems; Budapest Hungary
| | - Sandra Hartl
- Numerical Thermo-Fluid Dynamics; TU Bergakademie, Freiberg; Germany
| | - Christian Hasse
- Numerical Thermo-Fluid Dynamics; TU Bergakademie, Freiberg; Germany
| | - Tamás Turányi
- Institute of Chemistry; Eötvös University (ELTE); Budapest Hungary
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35
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Degirmenci I, Coote ML. Comparison of Thiyl, Alkoxyl, and Alkyl Radical Addition to Double Bonds: The Unusual Contrasting Behavior of Sulfur and Oxygen Radical Chemistry. J Phys Chem A 2016; 120:1750-5. [PMID: 26932454 DOI: 10.1021/acs.jpca.6b00538] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
High-level ab initio calculations have been used to compare prototypical thiyl, alkoxyl, and alkyl radical addition reactions. Thiyl radical addition to the sulfur center of thioketones is exothermic and rapid, occurring with negative enthalpic barriers and only weakly positive Gibbs free energy barriers. In stark contrast, alkoxyl radical addition to the oxygen center of ketones is highly endothermic and occurs with very high reaction barriers, though these are also suppressed. On the basis of analysis of the corresponding alkyl radical additions to these substrates and the corresponding reactions of these heteroatom radicals with alkenes, it suggested that addition reactions involving thiyl radicals have low intrinsic barriers because their unpaired electrons are better able to undergo stabilizing resonance interactions with the π* orbitals of the substrate in the transition state.
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Affiliation(s)
- Isa Degirmenci
- Chemical Engineering Department, Ondokuz Mayıs University , Samsun 55139, Turkey.,ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, The Australian National University , Canberra ACT 2601, Australia
| | - Michelle L Coote
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, The Australian National University , Canberra ACT 2601, Australia
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36
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Antonov IO, Kwok J, Zádor J, Sheps L. A Combined Experimental and Theoretical Study of the Reaction OH + 2-Butene in the 400–800 K Temperature Range. J Phys Chem A 2015; 119:7742-52. [DOI: 10.1021/acs.jpca.5b01012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ivan O. Antonov
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Justin Kwok
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Judit Zádor
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Leonid Sheps
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
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37
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Sivaramakrishnan R, Michael JV, Harding LB, Klippenstein SJ. Resolving Some Paradoxes in the Thermal Decomposition Mechanism of Acetaldehyde. J Phys Chem A 2015; 119:7724-33. [DOI: 10.1021/acs.jpca.5b01032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raghu Sivaramakrishnan
- Chemical Sciences & Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Joe V. Michael
- Chemical Sciences & Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Lawrence B. Harding
- Chemical Sciences & Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Stephen J. Klippenstein
- Chemical Sciences & Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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38
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Akbar Ali M, Barker JR. Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH2O, OH + CH2CH2, and OH + CH2NH. J Phys Chem A 2015; 119:7578-92. [DOI: 10.1021/acs.jpca.5b00910] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohamad Akbar Ali
- Department
of Atmospheric,
Ocean, and Space Sciences, The University of Michigan, Ann Arbor, Michigan 48109-2143, United States
| | - John R. Barker
- Department
of Atmospheric,
Ocean, and Space Sciences, The University of Michigan, Ann Arbor, Michigan 48109-2143, United States
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39
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Guo J, Xu J, Li Z, Tan N, Li X. Temperature and pressure dependent rate coefficients for the reaction of C2H4 + HO2 on the C2H4O2H potential energy surface. J Phys Chem A 2015; 119:3161-70. [PMID: 25774424 DOI: 10.1021/jp511991n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The potential energy surface (PES) for reaction C2H4 + HO2 was examined by using the quantum chemical methods. All rates were determined computationally using the CBS-QB3 composite method combined with conventional transition state theory(TST), variational transition-state theory (VTST) and Rice-Ramsberger-Kassel-Marcus/master-equation (RRKM/ME) theory. The geometries optimization and the vibrational frequency analysis of reactants, transition states, and products were performed at the B3LYP/CBSB7 level. The composite CBS-QB3 method was applied for energy calculations. The major product channel of reaction C2H4 + HO2 is the formation C2H4O2H via an OH(···)π complex with 3.7 kcal/mol binding energy which exhibits negative-temperature dependence. We further investigated the reactions related to this complex, which were ignored in previous studies. Thermochemical properties of the species involved in the reactions were determined using the CBS-QB3 method, and enthalpies of formation of species were compared with literature values. The calculated rate constants are in good agreement with those available from literature and given in modified Arrhenius equation form, which are serviceable in combustion modeling of hydrocarbons. Finally, in order to illustrate the effect for low-temperature ignition of our new rate constants, we have implemented them into the existing mechanisms, which can predict ethylene ignition in a shock tube with better performance.
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Affiliation(s)
- JunJiang Guo
- †College of Chemical Engineering, Sichuan University, Chengdu 610065, P.R. China
| | - JiaQi Xu
- ‡College of Chemistry, Sichuan University, Chengdu 610064, P.R. China
| | - ZeRong Li
- ‡College of Chemistry, Sichuan University, Chengdu 610064, P.R. China
| | - NingXin Tan
- †College of Chemical Engineering, Sichuan University, Chengdu 610065, P.R. China
| | - XiangYuan Li
- †College of Chemical Engineering, Sichuan University, Chengdu 610065, P.R. China
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40
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Brynteson MD, Butler LJ. Predicting the effect of angular momentum on the dissociation dynamics of highly rotationally excited radical intermediates. J Chem Phys 2015; 142:054301. [PMID: 25662639 DOI: 10.1063/1.4905776] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a model which accurately predicts the net speed distributions of products resulting from the unimolecular decomposition of rotationally excited radicals. The radicals are produced photolytically from a halogenated precursor under collision-free conditions so they are not in a thermal distribution of rotational states. The accuracy relies on the radical dissociating with negligible energetic barrier beyond the endoergicity. We test the model predictions using previous velocity map imaging and crossed laser-molecular beam scattering experiments that photolytically generated rotationally excited CD2CD2OH and C3H6OH radicals from brominated precursors; some of those radicals then undergo further dissociation to CD2CD2 + OH and C3H6 + OH, respectively. We model the rotational trajectories of these radicals, with high vibrational and rotational energy, first near their equilibrium geometry, and then by projecting each point during the rotation to the transition state (continuing the rotational dynamics at that geometry). This allows us to accurately predict the recoil velocity imparted in the subsequent dissociation of the radical by calculating the tangential velocities of the CD2CD2/C3H6 and OH fragments at the transition state. The model also gives a prediction for the distribution of angles between the dissociation fragments' velocity vectors and the initial radical's velocity vector. These results are used to generate fits to the previously measured time-of-flight distributions of the dissociation fragments; the fits are excellent. The results demonstrate the importance of considering the precession of the angular velocity vector for a rotating radical. We also show that if the initial angular momentum of the rotating radical lies nearly parallel to a principal axis, the very narrow range of tangential velocities predicted by this model must be convoluted with a J = 0 recoil velocity distribution to achieve a good result. The model relies on measuring the kinetic energy release when the halogenated precursor is photodissociated via a repulsive excited state but does not include any adjustable parameters. Even when different conformers of the photolytic precursor are populated, weighting the prediction by a thermal conformer population gives an accurate prediction for the relative velocity vectors of the fragments from the highly rotationally excited radical intermediates.
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Affiliation(s)
- Matthew D Brynteson
- Department of Chemistry and the James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
| | - Laurie J Butler
- Department of Chemistry and the James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
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41
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Liu P, Lin H, Yang Y, Shao C, Gu C, Huang Z. New insights into thermal decomposition of polycyclic aromatic hydrocarbon oxyradicals. J Phys Chem A 2014; 118:11337-45. [PMID: 25386793 DOI: 10.1021/jp510498j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermal decompositions of polycyclic aromatic hydrocarbon (PAH) oxyradicals on various surface sites including five-membered ring, free-edge, zigzag, and armchair have been systematically investigated by using ab initio density functional theory B3LYP/6-311+G(d,p) basis set. The calculation based on Hückel theory indicates that PAHs (3H-cydopenta[a]anthracene oxyradical) with oxyradicals on a five-membered ring site have high chemical reactivity. The rate coefficients of PAH oxyradical decomposition were evaluated by using Rice-Ramsperger-Kassel-Marcus theory and solving the master equations in the temperature range of 1500-2500 K and the pressure range of 0.1-10 atm. The kinetic calculations revealed that the rate coefficients of PAH oxyradical decomposition are temperature-, pressure-, and surface site-dependent, and the oxyradical on a five-membered ring is easier to decompose than that on a six-membered ring. Four-membered rings were found in decomposition of the five-membered ring, and a new reaction channel of PAH evolution involving four-membered rings is recommended.
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Affiliation(s)
- Peng Liu
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University , Shanghai 200240, China
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42
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Zhang Y, Sun J, Zhang W, Tang Y, Wang R. Theoretical study on the gas phase reaction of propargyl alcohol with hydroxyl radical. J Comput Chem 2014; 35:1646-56. [PMID: 24995629 DOI: 10.1002/jcc.23670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/03/2014] [Accepted: 06/08/2014] [Indexed: 11/11/2022]
Abstract
The reaction of propargyl alcohol with hydroxyl radical has been studied extensively at CCSD(T)/aug-cc-pVTZ//MP2/cc-pVTZ level. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for this important reaction in detail. Two reaction mechanisms were revealed, namely addition/elimination and hydrogen abstraction mechanism. The reaction mechanism confirms that OH addition to C≡C triple bond forms the chemically activated adducts, IM1 (·CHCOHCH2OH) and IM2 (CHOH·CCH2OH), and the hydrogen abstraction pathways (-CH2OH bonded to the carbon atom and alcohol hydrogen) may occur via low barriers. Harmonic model of Rice-Ramsperger-Kassel-Marcus theory and variational transition state theory are used to calculate the overall and individual rate constants over a wide range of temperatures and pressures. The calculated rate constants are in good agreement with the experimental data. At atmospheric pressure with Ar as bath gas, IM1 (·CHCOHCH2OH) and IM2 (CHOH·CCH2OH) formed by collisional stabilization are dominant in the low temperature range. The production of CHCCHOH + H2O via hydrogen abstraction becomes dominate at higher temperature. The fraction of IM3 (CH2COHCH2·O) is very significant over the moderate temperature range.
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Affiliation(s)
- Yunju Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin, 130024, People's Republic of China
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43
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Bunkan AJC, Tang Y, Sellevåg SR, Nielsen CJ. Atmospheric Gas Phase Chemistry of CH2═NH and HNC. A First-Principles Approach. J Phys Chem A 2014; 118:5279-88. [DOI: 10.1021/jp5049088] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Arne Joakim C. Bunkan
- Centre
for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern 0315, Oslo, Norway
| | - Yizhen Tang
- School
of Environmental and Municipal Engineering, Qingdao Technological University, Fushun Road 11, Qingdao, Shandong 266033, P.R. China
| | - Stig R. Sellevåg
- Centre
for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern 0315, Oslo, Norway
| | - Claus J. Nielsen
- Centre
for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern 0315, Oslo, Norway
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44
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Zhang Y, Chao K, Sun J, Zhang W, Shi H, Yao C, Su Z, Pan X, Zhang J, Wang R. Theoretical study on the gas phase reaction of allyl chloride with hydroxyl radical. J Chem Phys 2014; 140:084309. [PMID: 24588171 DOI: 10.1063/1.4865937] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The reaction of allyl chloride with the hydroxyl radical has been investigated on a sound theoretical basis. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for important pathways in detail. The reaction mechanism confirms that OH addition to the C=C double bond forms the chemically activated adducts, IM1 (CH2CHOHCH2Cl) and IM2 (CH2OHCHCH2Cl) via low barriers, and direct H-abstraction paths may also occur. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants. The calculated rate constants are in good agreement with the experimental data. At 100 Torr with He as bath gas, IM6 formed by collisional stabilization is the major products in the temperature range 200-600 K; the production of CH2CHCHCl via hydrogen abstractions becomes dominant at high temperatures (600-3000 K).
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Affiliation(s)
- Yunju Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Kai Chao
- Ningxia Entry-Exit Inspection and Quarantine Bureau, Yinchuan, Ningxia 750001, People's Republic of China
| | - Jingyu Sun
- College of Chemistry and Environmental Engineering, Hubei Normal University, Cihu Road 11, Huanshi, Hubei 435002, People's Republic of China
| | - Wanqiao Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Haijie Shi
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Cen Yao
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Zhongmin Su
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Xiumei Pan
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Jingping Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
| | - Rongshun Wang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, People's Republic of China
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45
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Dames EE. Master Equation Modeling of the Unimolecular Decompositions of α-Hydroxyethyl (CH3
CHOH) and Ethoxy (CH3
CH2
O) Radicals. INT J CHEM KINET 2014. [DOI: 10.1002/kin.20844] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Enoch E. Dames
- High-Temperature Gasdynamics Laboratory; Department of Mechanical Engineering; Stanford University Stanford CA 94305
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46
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Stranic I, Pang GA, Hanson RK, Golden DM, Bowman CT. Shock Tube Measurements of the Rate Constant for the Reaction Ethanol + OH. J Phys Chem A 2014; 118:822-8. [DOI: 10.1021/jp410853f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ivo Stranic
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Genny A. Pang
- Institute for Biological and Medical Imaging
(IBMI), Helmholtz Center Munich, Ingoldstädter Landstraße
1, 85764 Neuherberg, Germany
| | - Ronald K. Hanson
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - David M. Golden
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Craig T. Bowman
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
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47
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Zhang Y, Chao K, Pan X, Zhang J, Su Z, Wang R. Mechanism and kinetic study of 3-fluoropropene with hydroxyl radical reaction. J Mol Graph Model 2013; 48:18-27. [PMID: 24366002 DOI: 10.1016/j.jmgm.2013.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/04/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022]
Abstract
Potential energy surface for the reaction of hydroxyl radical (OH) with 3-fluoropropene (CH₂CHCH₂F) has been studied to evaluate the reaction mechanisms, possible products and rate constants. It has been shown that the CH₂CHCH₂F with OH reaction takes place via a barrierless addition/elimination and hydrogen abstraction mechanism. It is revealed for the first time that the initial step for the barrierless additional process involves a pre-reactive loosely bound complex (CR1) that is 1.60 kcal/mol below the energy of the reactants. Subsequently, the reaction bifurcates into two different pathways to form IM1 (CH₂CHOHCH₂F) and IM2 (CH₂OHCHCH₂F), which can decompose or isomerize to various products via complicated mechanisms. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants and branching ratios. At atmospheric pressure with He as bath gas, IM1 formed by collisional stabilization is dominated at T≤600 K; whereas the direct hydrogen abstraction leading to CH₂CHCHF and H₂O are the major products at temperatures between 600 and 3000 K, with estimated contribution of 72.9% at 1000 K. Furthermore, the predicted rate constants are in good agreement with the available experimental values.
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Affiliation(s)
- Yunju Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China
| | - Kai Chao
- Ningxia Entry-Exit Inspection and Quarantine Bureau, Yinchuan, Ningxia 750001, PR China
| | - Xiumei Pan
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China
| | - Jingping Zhang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China
| | - Zhongmin Su
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China
| | - Rongshun Wang
- Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China.
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Zhang J, Yang L, Troya D. Chemical Dynamics Simulations of the Hydroxyl Radical Reaction with Ethene. CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/06/765-773] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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McKown BG, Ceriotti M, Womack CC, Kamarchik E, Butler LJ, Bowman JM. Effects of High Angular Momentum on the Unimolecular Dissociation of CD2CD2OH: Theory and Comparisons with Experiment. J Phys Chem A 2013; 117:10951-63. [DOI: 10.1021/jp407913t] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benjamin G. McKown
- Department
of Chemistry and the James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Michele Ceriotti
- Institute
of Materials, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Caroline C. Womack
- Department
of Chemistry and the James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Eugene Kamarchik
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Laurie J. Butler
- Department
of Chemistry and the James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Joel M. Bowman
- Cherry
L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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Liljegren JA, Stevens PS. Measurements of the Kinetics of the Reaction of OH Radicals with 3-Methylfuran at Low Pressure. INT J CHEM KINET 2013. [DOI: 10.1002/kin.20814] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jennifer A. Liljegren
- School of Public and Environmental Affairs and Department of Chemistry; Indiana University Bloomington IN 47405
| | - Philip S. Stevens
- School of Public and Environmental Affairs and Department of Chemistry; Indiana University Bloomington IN 47405
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