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Watrous AG, Fortenberry RC. The fundamental vibrational frequencies and spectroscopic constants of the C 2O 2H 2 isomers: molecules known in simulated interstellar ice analogues. Phys Chem Chem Phys 2024. [PMID: 39076036 DOI: 10.1039/d4cp02201g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
While trans-glyoxal may not be easily observable in astronomical sources through either IR or radioastronomy due to its C2h symmetry, its cis conformer along with the cyc-H2COCO epoxide isomer should be ready targets for astrochemical detection. The present quantum chemical study shows that not only are both molecular isomers strongly polar, they also have notable IR features and low isomerisation energies of 4.1 kcal mol-1 and 10.7 kcal mol-1, respectively. These three isomers along with two other C2O2H2 isomers have had their full set of fundamental vibrational frequencies and spectroscopic constants characterised herein. These isomers have previously been shown to occur in simulated astrophysical ices making them worthy targets of astronomical search. Furthermore, the hybrid quartic force field (QFF) approach utilized herein to produce the needed spectral data has a mean absolute percent error compared to the experimentally-available, gas phase fundamental vibrational frequencies of 0.6% and rotational constants to better than 0.1%. The hybrid QFF is defined from explicitly correlated coupled cluster theory at the singles, doubles, and perturbative triples level [CCSD(T)-F12b] including core electron correlation and a canonical CCSD(T) relativity correction for the harmonic (quadratic) terms in the QFF and simple CCSD(T)-F12b/cc-pVDZ energies for the cubic and quartic terms, the so-called "F12-TcCR+DZ QFF." This method is producing spectroscopically-accurate predictions for both fundamental vibrational frequencies and principal spectroscopic constants. Hence, the values computed in this work should be notably accurate and, hence, exceptionally useful to the spectroscopy and astrochemistry communities.
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2
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Li Y, Wang Y, Zhang RM, He X, Xu X. Comprehensive Theoretical Study on Four Typical Intramolecular Hydrogen Shift Reactions of Peroxy Radicals: Multireference Character, Recommended Model Chemistry, and Kinetics. J Chem Theory Comput 2023. [PMID: 37164004 DOI: 10.1021/acs.jctc.3c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Intramolecular hydrogen shift reactions in peroxy radicals (RO2• → •QOOH) play key roles in the low-temperature combustion and in the atmospheric chemistry. In the present study, we found that a mild-to-moderate multireference character of a potential energy surface (PES) is widely present in four typical hydrogen shift reactions of peroxy radicals (RO2•, R = ethyl, vinyl, formyl methyl, and acetyl) by a systematic assessment based on the T1 diagnostic, %TAE diagnostic, M diagnostic, and contribution of the dominant configuration of the reference CASSCF wavefunction (C02). To assess the effects of these inherent multireference characters on electronic structure calculations, we compared the PESs of the four reactions calculated by the multireference method CASPT2 in the complete basis set (CBS) limit, single-reference method CCSD(T)-F12, and single-reference-based composite method WMS. The results showed that ignoring the multireference character will introduce a mean unsigned deviation (MUD) of 0.46-1.72 kcal/mol from CASPT2/CBS results by using the CCSD(T)-F12 method or a MUD of 0.49-1.37 kcal/mol by WMS for three RO2• reactions (R = vinyl, formyl methyl, and acetyl) with a stronger multireference character. Further tests by single-reference Kohn-Sham (KS) density functional theory methods showed even larger deviations. Therefore, we specifically developed a new hybrid meta-generalized gradient approximation (GGA) functional M06-HS for the four typical H-shift reactions of peroxy radicals based on the WMS results for the ethyl peroxy radical reaction and on the CASPT2/CBS results for the others. The M06-HS method has an averaged MUD of 0.34 kcal/mol over five tested basis sets against the benchmark PESs, performing best in the tested 38 KS functionals. Last, in a temperature range of 200-3000 K, with the new functional, we calculated the high-pressure-limit rate coefficients of these H-shift reactions by the multi-structural variational transition-state theory with the small-curvature tunneling approximation (MS-CVT/SCT) and the thermochemical properties of all of the involved key radicals by the multi-structural torsional (MS-T) anharmonicity approximation method.
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Affiliation(s)
- Yan Li
- Center for Combustion Energy, Department of Energy and Power Engineering, and Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Ying Wang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
- Peptide and Small Molecule Drug R&D Platform, Furong Laboratory, Hunan Normal University, Changsha 410081, Hunan, China
| | - Rui Ming Zhang
- Center for Combustion Energy, Department of Energy and Power Engineering, and Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- New York University-East China Normal University Center for Computational Chemistry, New York University Shanghai, Shanghai 200062, China
| | - Xuefei Xu
- Center for Combustion Energy, Department of Energy and Power Engineering, and Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China
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Sandhiya L, Senthilkumar K. Unimolecular decomposition of acetyl peroxy radical: a potential source of tropospheric ketene. Phys Chem Chem Phys 2020; 22:26819-26827. [PMID: 33231595 DOI: 10.1039/d0cp04590j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unimolecular decomposition of acetyl peroxy radicals followed by subsequent nitration is known to lead to the formation of peroxy acetyl nitrate (PAN) in the troposphere. Using high level quantum chemical calculations, we show that the acetyl peroxy radical is a precursor in the formation of tropospheric ketene. The results show that the presence of a single or double water molecule(s) as a catalyst does not influence the decomposition reaction directly to form ketene and hydroperoxy radicals. The electronic excitation of the reactive and product complexes occurs in the wavelength range of ∼1400 nm, suggesting that the complexes undergo photoexcitation in the near IR region. The results ascertain that the dissociation of acetyl peroxy radicals into ketene and hydroperoxy radicals occurs more likely through the excitation route and the corresponding excitation wavelength reveals that the reactions are red-light driven. Three different product complexes, ketene·HO2, ketene·H2O·HO2 and ketene·(H2O)2·HO2, are formed from the reaction. The direct dynamics simulations show that the product complexes are more stable and possess a long lifetime. The calculated temperature dependent equilibrium constant of the product complexes reveals that their atmospheric abundances decrease with increasing altitudes.
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Affiliation(s)
- L Sandhiya
- CSIR - National Institute of Science, Technology and Development Studies, New Delhi-110012, India.
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Vansco MF, Caravan RL, Zuraski K, Winiberg FAF, Au K, Trongsiriwat N, Walsh PJ, Osborn DL, Percival CJ, Khan MAH, Shallcross DE, Taatjes CA, Lester MI. Experimental Evidence of Dioxole Unimolecular Decay Pathway for Isoprene-Derived Criegee Intermediates. J Phys Chem A 2020; 124:3542-3554. [PMID: 32255634 DOI: 10.1021/acs.jpca.0c02138] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ozonolysis of isoprene, one of the most abundant volatile organic compounds emitted into the Earth's atmosphere, generates two four-carbon unsaturated Criegee intermediates, methyl vinyl ketone oxide (MVK-oxide) and methacrolein oxide (MACR-oxide). The extended conjugation between the vinyl substituent and carbonyl oxide groups of these Criegee intermediates facilitates rapid electrocyclic ring closures that form five-membered cyclic peroxides, known as dioxoles. This study reports the first experimental evidence of this novel decay pathway, which is predicted to be the dominant atmospheric sink for specific conformational forms of MVK-oxide (anti) and MACR-oxide (syn) with the vinyl substituent adjacent to the terminal O atom. The resulting dioxoles are predicted to undergo rapid unimolecular decay to oxygenated hydrocarbon radical products, including acetyl, vinoxy, formyl, and 2-methylvinoxy radicals. In the presence of O2, these radicals rapidly react to form peroxy radicals (ROO), which quickly decay via carbon-centered radical intermediates (QOOH) to stable carbonyl products that were identified in this work. The carbonyl products were detected under thermal conditions (298 K, 10 Torr He) using multiplexed photoionization mass spectrometry (MPIMS). The main products (and associated relative abundances) originating from unimolecular decay of anti-MVK-oxide and subsequent reaction with O2 are formaldehyde (88 ± 5%), ketene (9 ± 1%), and glyoxal (3 ± 1%). Those identified from the unimolecular decay of syn-MACR-oxide and subsequent reaction with O2 are acetaldehyde (37 ± 7%), vinyl alcohol (9 ± 1%), methylketene (2 ± 1%), and acrolein (52 ± 5%). In addition to the stable carbonyl products, the secondary peroxy chemistry also generates OH or HO2 radical coproducts.
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Affiliation(s)
- Michael F Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Rebecca L Caravan
- NASA Postdoctoral Program, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kristen Zuraski
- NASA Postdoctoral Program, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Frank A F Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,California Institute of Technology, Pasadena, California 91125, United States
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Nisalak Trongsiriwat
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Patrick J Walsh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Carl J Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,California Institute of Technology, Pasadena, California 91125, United States
| | - M Anwar H Khan
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Dudley E Shallcross
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Craig A Taatjes
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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5
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Wang SN, Wu RR, Wang LM. Role of hydrogen migrations in carbonyl peroxy radicals in the atmosphere. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1811265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Sai-nan Wang
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Run-run Wu
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Li-ming Wang
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou 510006, China
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Yu X, Hou H, Wang B. Double-Layered Composite Methods Extrapolating to Complete Basis-Set Limit for the Systems Involving More than Ten Heavy Atoms: Application to the Reaction of Heptafluoroisobutyronitrile with Hydroxyl Radical. J Phys Chem A 2017; 121:9020-9032. [DOI: 10.1021/acs.jpca.7b08844] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaojuan Yu
- College of Chemistry and
Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Hua Hou
- College of Chemistry and
Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Baoshan Wang
- College of Chemistry and
Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
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7
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Pfeifle M, Olzmann M. Consecutive Chemical Activation Steps in the OH-Initiated Atmospheric Degradation of Isoprene: An Analysis with Coupled Master Equations. INT J CHEM KINET 2014. [DOI: 10.1002/kin.20849] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mark Pfeifle
- Institut für Physikalische Chemie; Karlsruher Institut für Technologie; 76131 Karlsruhe Germany
| | - Matthias Olzmann
- Institut für Physikalische Chemie; Karlsruher Institut für Technologie; 76131 Karlsruhe Germany
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Groß CBM, Dillon TJ, Crowley JN. Pressure dependent OH yields in the reactions of CH3CO and HOCH2CO with O2. Phys Chem Chem Phys 2014; 16:10990-8. [DOI: 10.1039/c4cp01108b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhang Y, Sun J, Chao K, Sun H, Wang F, Tang S, Pan X, Zhang J, Wang R. Mechanistic and kinetic study the reaction of O(3P) + CH3CFCH2. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1100-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Allen JW, Goldsmith CF, Green WH. Automatic estimation of pressure-dependent rate coefficients. Phys Chem Chem Phys 2012; 14:1131-55. [DOI: 10.1039/c1cp22765c] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Vereecken L, Francisco JS. Theoretical studies of atmospheric reaction mechanisms in the troposphere. Chem Soc Rev 2012; 41:6259-93. [DOI: 10.1039/c2cs35070j] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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12
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ZHANG LIDONG, PAN YANG, QI FEI. THEORETICAL STUDIES ON PHOTOIONIZATION OF GUANINE TAUTOMERS AND INTERCONVERSION OF CATION RADICALS. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633609005404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The G3MP2B3 and P3 methods have been used to calculate the adiabatic and vertical ionization potentials (IPs) of the eight most stable tautomers of guanine. The calculated energy discrepancy between adiabatic and vertical IPs are in good agreement with the changes in geometry from neutral ground state to stable cation radicals. The geometries of imino-oxo form tautomers have no obvious change in the ionization process, which results in less energy discrepancy between vertical and adiabatic IPs. In the ionization process, the geometries of the amino-oxo and amino-hydroxy form tautomers change from nonplanar to planar structures. Hence the amino-oxo and amino-hydroxy form tautomers have larger energy discrepancy between vertical and adiabatic IPs. Further studies on the interconversion of the cation radicals shed further light on the transition process between the cation radicals and the main pathways are the hydrogen migrations and internal rotations of hydroxy (OH) and imino (NH) groups. The barriers of hydrogen rotations are lower than those of hydrogen migrations. Furthermore, the barriers for the hydrogen migrations between two rings are higher, which are about 3.0 eV.
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Affiliation(s)
- LIDONG ZHANG
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - YANG PAN
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - FEI QI
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
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Han D, Cao H, Sun Y, He M. Mechanistic and kinetic study on the ozonolysis of ethyl vinyl ether and propyl vinyl ether. Struct Chem 2011. [DOI: 10.1007/s11224-011-9899-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Seakins PW, Blitz MA. Developments in Laboratory Studies of Gas-Phase Reactions for Atmospheric Chemistry with Applications to Isoprene Oxidation and Carbonyl Chemistry. Annu Rev Phys Chem 2011; 62:351-73. [PMID: 21219141 DOI: 10.1146/annurev-physchem-032210-102538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Laboratory studies of gas-phase chemical processes are a key tool in understanding the chemistry of our atmosphere and hence tackling issues such as climate change and air quality. Laboratory techniques have improved considerably with greater emphasis on product detection, allowing the measurement of site-specific rate coefficients. Radical chemistry lies at the heart of atmospheric chemistry. In this review we consider issues around radical generation and recycling from the oxidation of isoprene and from the chemical reactions and photolysis of carbonyl species. Isoprene is the most globally significant hydrocarbon, but uncertainties exist about its oxidation in unpolluted environments. Recent experiments and calculations that cast light on radical generation are reviewed. Carbonyl compounds are the dominant first-generation products from hydrocarbon oxidation. Chemical oxidation can recycle radicals, or photolysis can be a net radical source. Studies have demonstrated that high-resolution and temperature-dependent studies are important for some significant species.
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Affiliation(s)
| | - Mark A. Blitz
- School of Chemistry, University of Leeds, Leeds, LS2 9JT United Kingdom;
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15
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Glowacki DR, Pilling MJ. Unimolecular Reactions of Peroxy Radicals in Atmospheric Chemistry and Combustion. Chemphyschem 2010; 11:3836-43. [DOI: 10.1002/cphc.201000469] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- David R. Glowacki
- Centre for Computational Chemistry, University of Bristol, Bristol BS8 1TS (UK)
| | - Michael J. Pilling
- School of Chemistry, University of Leeds, Leeds, LS2 9JT (UK), Fax: (+44) 113‐3436401
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17
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Wang F, Sun H, Sun J, Jia X, Zhang Y, Tang Y, Pan X, Su Z, Hao L, Wang R. Mechanistic and kinetic study of CH2O+O3 reaction. J Phys Chem A 2010; 114:3516-22. [PMID: 20175584 DOI: 10.1021/jp910754b] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Both singlet and triplet potential energy surfaces for the reaction of ground-state formaldehyde (CH(2)O) and ozone (O(3)) are theoretically investigated at the BMC-CCSD//BHandHLYP/6-311+G(d,p) level. Various possible isomerization and dissociation pathways are probed. Hydrogen abstraction, oxygen abstraction, and C-addition/elimination are found on both the singlet and the triplet surfaces. The major products for the total reaction are HCO and HOOO, which are generated via hydrogen abstraction. The transition state theory (TST) and multichannel RRKM calculations have been carried out for the total and individual rate constants for determinant channels over a wide range of temperatures and pressures.
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Affiliation(s)
- Fang 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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18
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Chen SY, Lee YP. Transient infrared absorption of t-CH3C(O)OO, c-CH3C(O)OO, and alpha-lactone recorded in gaseous reactions of CH3CO and O2. J Chem Phys 2010; 132:114303. [PMID: 20331293 DOI: 10.1063/1.3352315] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A step-scan Fourier-transform infrared spectrometer coupled with a multipass absorption cell was utilized to monitor the transient species produced in gaseous reactions of CH(3)CO and O(2); IR absorption spectra of CH(3)C(O)OO and alpha-lactone were observed. Absorption bands with origins at 1851+/-1, 1372+/-2, 1169+/-6, and 1102+/-3 cm(-1) are attributed to t-CH(3)C(O)OO, and those at 1862+/-3, 1142+/-4, and 1078+/-6 cm(-1) are assigned to c-CH(3)C(O)OO. A weak band near 1960 cm(-1) is assigned to alpha-lactone, cyc-CH(2)C(=O)O, a coproduct of OH. These observed rotational contours agree satisfactorily with simulated bands based on predicted rotational parameters and dipole derivatives, and observed vibrational wavenumbers agree with harmonic vibrational wavenumbers predicted with B3LYP/aug-cc-pVDZ density-functional theory. The observed relative intensities indicate that t-CH(3)C(O)OO is more stable than c-CH(3)C(O)OO by 3+/-2 kJ mol(-1). Based on these observations, the branching ratio for the OH+alpha-lactone channel of the CH(3)CO+O(2) reaction is estimated to be 0.04+/-0.01 under 100 Torr of O(2) at 298 K. A simple kinetic model is employed to account for the decay of CH(3)C(O)OO.
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Affiliation(s)
- Sun-Yang Chen
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
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19
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Sun J, Tang Y, Jia X, Wang F, Sun H, Feng J, Pan X, Hao L, Wang R. Theoretical study for the reaction of CH3CN with O(P3). J Chem Phys 2010; 132:064301. [DOI: 10.1063/1.3292570] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Sun J, Tang Y, Jia X, Wang F, Sun H, Zhang Y, Tang S, Wang F, Chang Y, Lu Y, Pan X, Zhang J, Wang R. Computational study of oxygen atom (3P and 1D) reactions with CF3CN. Phys Chem Chem Phys 2010; 12:10846-56. [DOI: 10.1039/c004284f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Xin YN, Zhao M, Li ZS, Xiong W, Song X, Hou H, Wang B. Theoretical Investigation of the Reaction of Imidogen with Fulminic Acid. J Chem Theory Comput 2009; 5:2021-9. [DOI: 10.1021/ct9002288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Sun J, Tang Y, Sun H, Jia X, Pan X, Wang R. Theoretical and kinetic study of the H + C2H5CN reaction. J Comput Chem 2009; 31:1126-34. [DOI: 10.1002/jcc.21397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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23
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Sun J, Tang Y, Sun H, Pan Y, Jia X, Pan X, Wang R. Mechanistic and kinetic study of the OH+C2H5CN reaction. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.08.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Hou H, Wang B. Ab initio study of the reaction of propionyl (C2H5CO) radical with oxygen (O2). J Chem Phys 2007; 127:054306. [PMID: 17688339 DOI: 10.1063/1.2756538] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The reaction of propionyl radical with oxygen has been studied using the full coupled cluster theory with the complete basis set. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for this important reaction in detail. The reaction takes place via a chemical activation mechanism. The barrierless association of propionyl with oxygen produces the propionylperoxy radical, which decomposes to form the hydroxyl radical and the three-center alpha-lactone predominantly or the four-center beta-propiolactone. The oxidation of propionyl radical to carbon monoxide or carbon dioxide is not straightforward rather via the secondary decomposition of alpha-lactone and beta-propiolactone. Kinetically, the overall rate constant is almost pressure independent and it approaches the high-pressure limit around tens of torr of helium. At temperatures below 600 K, the rate constant shows negative temperature dependence. The experimental yields of the hydroxyl radical can be well reproduced, with the average energy transferred per collision -DeltaE=20-25 cm(-1) at 213 and 295 K (helium bath gas). At low pressures, together with the hydroxy radical, alpha-lactone is the major product, while beta-propiolactone only accounts for about one-fifth of alpha-lactone. At the high-pressure limit, the production of the propionylperoxy radical is dominant together with a fraction of the isomers. The infrared spectroscopy or the mass spectroscopy techniques are suggested to be employed in the future experimental study of the C2H5CO+O2 reaction.
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Affiliation(s)
- Hua Hou
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, People's Republic of China
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Kovács G, Zádor J, Farkas E, Nádasdi R, Szilágyi I, Dóbé S, Bérces T, Márta F, Lendvay G. Kinetics and mechanism of the reactions of CH3CO and CH3C(O)CH2 radicals with O2. Low-pressure discharge flow experiments and quantum chemical computations. Phys Chem Chem Phys 2007; 9:4142-54. [PMID: 17687464 DOI: 10.1039/b706216h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions CH(3)CO + O(2)--> products (1), CH(3)CO + O(2)--> OH +other products (1b) and CH(3)C(O)CH(2) + O(2)--> products (2) have been studied in isothermal discharge flow reactors with laser induced fluorescence monitoring of OH and CH(3)C(O)CH(2) radicals. The experiments have been performed at overall pressures between 1.33 and 10.91 mbar of helium and 298 +/- 1 K reaction temperature. OH formation has been found to be the dominant reaction channel for CH(3)CO + O(2): the branching ratio, Gamma(1b) = k(1b)/k(1), is close to unity at around 1 mbar, but decreases rapidly with increasing pressure. The rate constant of the overall reaction, k(2), has been found to be pressure dependent: the fall-off behaviour has been analysed in comparison with reported data. Electronic structure calculations have confirmed that at room temperature the reaction of CH(3)C(O)CH(2) with O(2) is essentially a recombination-type process. At high temperatures, the further reactions of the acetonyl-peroxyl adduct may yield OH radicals, but the most probable channel seems to be the O(2)-catalysed keto-enol transformation of acetonyl. Implications of the results for atmospheric modelling studies have been discussed.
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Affiliation(s)
- Gergely Kovács
- Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út 59-67, H-1025 Budapest, Hungary
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Maranzana A, Barker JR, Tonachini G. Master equation simulations of competing unimolecular and bimolecular reactions: application to OH production in the reaction of acetyl radical with O2. Phys Chem Chem Phys 2007; 9:4129-41. [PMID: 17687463 DOI: 10.1039/b705116f] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Master equation calculations were carried out to simulate the production of hydroxyl free radicals initiated by the reaction of acetyl free radicals (CH3(C=O).) with molecular oxygen. In particular, the competition between the unimolecular reactions and bimolecular reactions of vibrationally excited intermediates was modeled by using a single master equation. The vibrationally excited intermediates (isomers of acetylperoxyl radicals) result from the initial reaction of acetyl free radical with O2. The bimolecular reactions were modeled using a novel pseudo-first-order microcanonical rate constant approach. Stationary points on the multi-well, multi-channel potential energy surface (PES) were calculated at the DFT(B3LYP)/6-311G(2df,p) level of theory. Some additional calculations were carried out at the CASPT2(7,5)/6-31G(d) level of theory to investigate barrierless reactions and other features of the PES. The master equation simulations are in excellent agreement with the experimental OH yields measured in N2 or He buffer gas near 300 K, but they do not explain a recent report that the OH yields are independent of pressure in nearly pure O2 buffer gas.
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Affiliation(s)
- Andrea Maranzana
- Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA
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Sanna N, Castrignano T, De Meo PD, Carrabino D, Grandi A, Morelli G, Caruso P, Barone V. Gaussian grid: a computational chemistry experiment over a web service-oriented grid. Theor Chem Acc 2006. [DOI: 10.1007/s00214-006-0227-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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