151
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Chen S, Zhao Y, Zhang R. Formation Mechanism of Atmospheric Ammonium Bisulfate: Hydrogen-Bond-Promoted Nearly Barrierless Reactions of SO3
with NH3
and H2
O. Chemphyschem 2018; 19:967-972. [DOI: 10.1002/cphc.201701333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Shunwei Chen
- Department of Physics; City University of Hong Kon; 83 Tat Chee Avenue Kowloon, Hong Kong SAR China
| | - Yanling Zhao
- Department of Physics; City University of Hong Kon; 83 Tat Chee Avenue Kowloon, Hong Kong SAR China
| | - Ruiqin Zhang
- Department of Physics; City University of Hong Kon; 83 Tat Chee Avenue Kowloon, Hong Kong SAR China
- Shenzhen Research Institut; City University of Hong Kong; Shenzhen China
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152
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Vereecken L, Novelli A, Taraborrelli D. Unimolecular decay strongly limits the atmospheric impact of Criegee intermediates. Phys Chem Chem Phys 2018; 19:31599-31612. [PMID: 29182168 DOI: 10.1039/c7cp05541b] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Stabilized Criegee intermediates (SCI) are reactive oxygenated species formed in the ozonolysis of hydrocarbons. Their chemistry could influence the oxidative capacity of the atmosphere by affecting the HOx and NOx cycles, or by the formation of low-volatility oxygenates enhancing atmospheric aerosols known to have an important impact on climate. The concentration of SCI in the atmosphere has hitherto not been determined reliably, and very little is known about their speciation. Here we show that the concentration of biogenic SCI is strongly limited by their unimolecular decay, based on extensive theory-based structure-activity relationships (SARs) for the reaction rates for decomposition. Reaction with water vapor, H2O and (H2O)2 molecules, is the second most important loss process; SARs are also proposed for these reactions. For SCI derived from the most common biogenic VOCs, we find that unimolecular decay is responsible for just over half of the loss, with reaction with water vapor the main remaining loss process. Reactions with SO2, NO2, or acids have negligible impact on the atmospheric SCI concentration. The ambient SCI concentrations are further characterized by analysis of field data with speciated hydrocarbon information, and by implementation of the chemistry in a global chemistry model. The results show a highly complex SCI speciation, with an atmospheric peak SCI concentrations below 1 × 105 molecule cm-3, and annual average SCI concentrations less than 7 × 103 molecule cm-3. We find that SCI have only a negligible impact on the global gas phase H2SO4 formation or removal of oxygenates, though some contribution around the equatorial belt, and in select regions, cannot be excluded.
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Affiliation(s)
- L Vereecken
- Forschungszentrum Jülich GmbH, Institute for Energy and Climate, IEK-8 Troposphere, 52428 Jülich, Germany.
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153
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Vereecken L. The reaction of Criegee intermediates with acids and enols. Phys Chem Chem Phys 2018; 19:28630-28640. [PMID: 29057418 DOI: 10.1039/c7cp05132h] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The reaction of CH2OO, the smallest carbonyl oxide (Criegee intermediate, CI), with several acids was investigated using the CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ quantum chemical method, as well as microvariational transition state theory and RRKM master equation theoretical kinetic methodologies. For oxoacids HNO3 and HCOOH, a 1,4-insertion mechanism allows for barrierless reactions with high rate coefficients, in agreement with literature experimental data. This mechanism relies on the presence of a double bond in the α-position to the acidic OH group. We predict that reactions of CI with enols will likewise have high rate coefficients, proceeding through a similar mechanism. The hydracid HCl was found to react through a less favorable 1,2-insertion reaction, leading to lower rate coefficients, again in good agreement with the literature. We conclude that the reaction mechanism is the main indicator for the reaction rate for CH2OO + acid reactions, with acidity only of secondary influence. At room temperature and 1 atm the main product for all reactions was found to be the thermalized hydroperoxide initial adduct, with minor yields of fragmentation products. One of the product channels characterized is a novel reaction path involving intramolecular H-abstraction after a roaming reaction in the OH + product radical complex formed by the dissociation of the hydroperoxide adduct; this channel is the lowest fragmentation route for some of the reactions studied.
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Affiliation(s)
- L Vereecken
- Forschungszentrum Jülich GmbH, Institute for Energy and Climate Research, IEK-8 Troposphere, 52428 Jülich, Germany.
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154
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Hoyermann K, Mauß F, Olzmann M, Welz O, Zeuch T. Exploring the chemical kinetics of partially oxidized intermediates by combining experiments, theory, and kinetic modeling. Phys Chem Chem Phys 2018; 19:18128-18146. [PMID: 28681879 DOI: 10.1039/c7cp02759a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Partially oxidized intermediates play a central role in combustion and atmospheric chemistry. In this perspective, we focus on the chemical kinetics of alkoxy radicals, peroxy radicals, and Criegee intermediates, which are key species in both combustion and atmospheric environments. These reactive intermediates feature a broad spectrum of chemical diversity. Their reactivity is central to our understanding of how volatile organic compounds are degraded in the atmosphere and converted into secondary organic aerosol. Moreover, they sensitively determine ignition timing in internal combustion engines. The intention of this perspective article is to provide the reader with information about the general mechanisms of reactions initiated by addition of atomic and molecular oxygen to alkyl radicals and ozone to alkenes. We will focus on critical branching points in the subsequent reaction mechanisms and discuss them from a consistent point of view. As a first example of our integrated approach, we will show how experiment, theory, and kinetic modeling have been successfully combined in the first infrared detection of Criegee intermediates during the gas phase ozonolysis. As a second example, we will examine the ignition timing of n-heptane/air mixtures at low and intermediate temperatures. Here, we present a reduced, fuel size independent kinetic model of the complex chemistry initiated by peroxy radicals that has been successfully applied to simulate standard n-heptane combustion experiments.
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Affiliation(s)
- Karlheinz Hoyermann
- Georg-August-Universität Göttingen, Institut für Physikalische Chemie, Tammannstraße 6, 37077 Göttingen, Germany.
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155
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Anglada JM, Solé A. Impact of the water dimer on the atmospheric reactivity of carbonyl oxides. Phys Chem Chem Phys 2018; 18:17698-712. [PMID: 27308802 DOI: 10.1039/c6cp02531e] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of twelve carbonyl oxides or Criegee intermediates with the water monomer and with the water dimer have been investigated employing high level theoretical methods. The study includes all possible carbonyl oxides arising from the isoprene ozonolysis and the methyl and dimethyl carbonyl oxides that originated from the reaction of ozone with several hydrocarbons. These reactions have great significance in the chemistry of the atmosphere because Criegee intermediates have recently been identified as important oxidants in the troposphere and as precursors of secondary organic aerosols. Moreover, water vapor is one of the most abundant trace gases in the atmosphere and the water dimer can trigger the atmospheric decomposition of Criegee intermediates. Our calculations show that the nature and position of the substituents in carbonyl oxides play a very important role in the reactivity of these species with both the water monomer and the water dimer. This fact results in differences in rate constants of up to six orders of magnitude depending on the carbonyl oxide. In this work we have defined an effective rate constant (keff) for the atmospheric reaction of carbonyl oxides with water vapor, which depends on the temperature and on the relative humidity as well. With this keff we show that the water dimer, despite its low tropospheric concentration, enhances the atmospheric reactivity of Criegee intermediates, but its effect changes with the nature of carbonyl oxide, ranging between 59 and 295 times in the most favorable case (syn-methyl carbonyl oxide), and between 1.4 and 3 times only in the most unfavorable case.
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Affiliation(s)
- Josep M Anglada
- Departament de Química Biològica i Modelització Molecular, (IQAC - CSIC), Jordi Girona, 18-26, E-08034 Barcelona, Spain.
| | - Albert Solé
- Departament de Ciència de Materials i Química Física, i Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Martí i Franqués, 1, E-08028 Barcelona, Spain
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156
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Monteiro JGS, Barbosa AGH, Henriques AM, Neves PHG, Furtado RS, Menezes RM, Dos Santos AR, Fleming FP. Assessing the Molecular Basis of the Fuel Octane Scale: A Detailed Investigation on the Rate Controlling Steps of the Autoignition of Heptane and Isooctane. J Phys Chem A 2018; 122:610-630. [PMID: 29257685 DOI: 10.1021/acs.jpca.7b08521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Heptane and 2,2,4-trimethylpentane (isooctane) are the key species in the modeling of ignition of hydrocarbon-based fuel formulations. Isooctane is knock-resistant whereas n-heptane is a very knock-prone hydrocarbon. It has been suggested that interconversion of their associated alkylperoxy and hydroperoxyalkyl species via hydrogen-transfer isomerization reaction is the key step to understand their different knocking behavior. In this work, the kinetics of unimolecular hydrogen-transfer reactions of n-heptylperoxy and isooctylperoxy are determined using canonical variational transition-state theory and multidimensional small curvature tunneling. Internal rotation of involved molecules is taken explicitly into account in the molecular partition function. The rate coefficients are calculated in the temperature range 300-900 K, relevant to low-temperature autoignition. The concerted HO2 elimination is an important reaction that competes with some H-transfer and is associated with chain termination. Thus, the branching ratio between these reaction channels is analyzed. We show that variational and multidimensional tunneling effects cannot be neglected for the H-transfer reaction. In particular, the pre-exponential Arrhenius fitting parameter derived from our rate constants shows a strong dependence on the temperature, because tunneling increases quickly at temperatures below 500 K. On the basis of our results, the existing qualitative model for the reasons for different knock behavior observed for n-heptane and isooctane is quantitatively validated at the molecular level.
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Affiliation(s)
- João G S Monteiro
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
| | - André G H Barbosa
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
| | - André M Henriques
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
| | - Pedro H G Neves
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
| | - Roberto S Furtado
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
| | - Rodrigo M Menezes
- Instituto de Química, Universidade Federal Fluminense , Niterói-RJ 20141-020, Brazil
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157
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Grambow CA, Jamal A, Li YP, Green WH, Zádor J, Suleimanov YV. Unimolecular Reaction Pathways of a γ-Ketohydroperoxide from Combined Application of Automated Reaction Discovery Methods. J Am Chem Soc 2018; 140:1035-1048. [DOI: 10.1021/jacs.7b11009] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Colin A. Grambow
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, United States
| | - Adeel Jamal
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, United States
| | - Yi-Pei Li
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, United States
| | - William H. Green
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, United States
| | - Judit Zádor
- Combustion
Research Facility, Sandia National Laboratories, 7011 East Ave., Livermore, California 94551, United States
| | - Yury V. Suleimanov
- Computation-based
Science and Technology Research Center, Cyprus Institute, 20
Kavafi Str., Nicosia 2121, Cyprus
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158
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Praske E, Otkjær RV, Crounse JD, Hethcox JC, Stoltz BM, Kjaergaard HG, Wennberg PO. Atmospheric autoxidation is increasingly important in urban and suburban North America. Proc Natl Acad Sci U S A 2018; 115:64-69. [PMID: 29255042 PMCID: PMC5776813 DOI: 10.1073/pnas.1715540115] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gas-phase autoxidation-regenerative peroxy radical formation following intramolecular hydrogen shifts-is known to be important in the combustion of organic materials. The relevance of this chemistry in the oxidation of organics in the atmosphere has received less attention due, in part, to the lack of kinetic data at relevant temperatures. Here, we combine computational and experimental approaches to investigate the rate of autoxidation for organic peroxy radicals (RO2) produced in the oxidation of a prototypical atmospheric pollutant, n-hexane. We find that the reaction rate depends critically on the molecular configuration of the RO2 radical undergoing hydrogen transfer (H-shift). RO2 H-shift rate coefficients via transition states involving six- and seven-membered rings (1,5 and 1,6 H-shifts, respectively) of α-OH hydrogens (HOC-H) formed in this system are of order 0.1 s-1 at 296 K, while the 1,4 H-shift is calculated to be orders of magnitude slower. Consistent with H-shift reactions over a substantial energetic barrier, we find that the rate coefficients of these reactions increase rapidly with temperature and exhibit a large, primary, kinetic isotope effect. The observed H-shift rate coefficients are sufficiently fast that, as a result of ongoing NO x emission reductions, autoxidation is now competing with bimolecular chemistry even in the most polluted North American cities, particularly during summer afternoons when NO levels are low and temperatures are elevated.
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Affiliation(s)
- Eric Praske
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Rasmus V Otkjær
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - John D Crounse
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - J Caleb Hethcox
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Brian M Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark;
| | - Paul O Wennberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125;
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
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159
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Zhang Q, Lin X, Gai Y, Ma Q, Zhao W, Fang B, Long B, Zhang W. Kinetic and mechanistic study on gas phase reactions of ozone with a series ofcis-3-hexenyl esters. RSC Adv 2018. [DOI: 10.1039/c7ra13369c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Reaction kinetics of O3with fourcis-3-hexenyl esters were studied using experimental methods in a flow tube reactor as well as using theoretical methods.
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Affiliation(s)
- Qilei Zhang
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Xiaoxiao Lin
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Yanbo Gai
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Qiao Ma
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Weixiong Zhao
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Bo Fang
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Bo Long
- School of Materials Science and Engineering
- Guizhou Minzu University
- Guiyang 550025
- China
| | - Weijun Zhang
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
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160
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Misiewicz JP, Elliott SN, Moore KB, Schaefer HF. Re-examining ammonia addition to the Criegee intermediate: converging to chemical accuracy. Phys Chem Chem Phys 2018; 20:7479-7491. [DOI: 10.1039/c7cp08582f] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Theory shows ammonia is unlikely to be significant in Criegee chemistry and demonstrates the importance of perturbative quadruple excitations in Criegee chemistry.
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Affiliation(s)
| | - Sarah N. Elliott
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- Georgia
| | - Kevin B. Moore
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- Georgia
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- Georgia
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161
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Xiao P, Yang JJ, Fang WH, Cui G. QM/MM studies on ozonolysis of α-humulene and Criegee reactions with acids and water at air–water/acetonitrile interfaces. Phys Chem Chem Phys 2018; 20:16138-16150. [DOI: 10.1039/c8cp01750f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
QM/MM electronic structure calculations reveal important mechanistic insights on the ozonolysis of α-humulene and Criegee reactions with acids and water at air–water/acetonitrile interfaces.
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Affiliation(s)
- Pin Xiao
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Jia-Jia Yang
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
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162
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Sršeň Š, Hollas D, Slavíček P. UV absorption of Criegee intermediates: quantitative cross sections from high-level ab initio theory. Phys Chem Chem Phys 2018; 20:6421-6430. [DOI: 10.1039/c8cp00199e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Criegee Intermediates (CIs) are important intermediates in atmospheric and combustion chemistry. We quantitatively model their UV absorption spectra using ab initio techniques.
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Affiliation(s)
- Š. Sršeň
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
| | - D. Hollas
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
| | - P. Slavíček
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
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163
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Kroeger AA, Karton A. A Computational Investigation of the Uncatalysed and Water-Catalysed Acyl Rearrangements in Ingenol Esters. Aust J Chem 2018. [DOI: 10.1071/ch17501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ingenol esters have been identified as potent anticancer and HIV latency reversing agents. Ingenol-3-angelate was recently approved as a topical treatment for precancerous actinic keratosis skin lesions. It was found, however, that ingenol esters can undergo a series of acyl rearrangements, which may affect their biological potency and the shelf-life of drug formulations. We use double-hybrid density functional theory to explore the mechanisms for the uncatalysed and water-catalysed acyl migrations in a model ingenol ester. The uncatalysed reaction may proceed either via a concerted mechanism or via a stepwise mechanism that involves a chiral orthoester intermediate. We find that the stepwise pathway is kinetically preferred by a significant amount of ΔΔH‡298 = 44.5 kJ mol−1. The uncatalysed 3-O-acyl to 5-O-acyl and 5-O-acyl to 20-O-acyl stepwise rearrangements involve cyclisation and ring-opening steps, both concomitant with a proton transfer. We find that the ring-opening step is the rate-determining step for both rearrangements, with reaction barrier heights of ΔH‡298 = 251.6 and 177.1 kJ mol−1 respectively. The proton transfers in the cyclisation and ring-opening steps may be catalysed by a water molecule. The water catalyst reduces the reaction barrier heights of these steps by over 90 kJ mol−1.
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164
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Tadayon SV, Foreman ES, Murray C. Kinetics of the Reactions between the Criegee Intermediate CH2OO and Alcohols. J Phys Chem A 2017; 122:258-268. [DOI: 10.1021/acs.jpca.7b09773] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sara V. Tadayon
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
| | - Elizabeth S. Foreman
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
| | - Craig Murray
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
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165
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Affiliation(s)
- Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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166
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Green AM, Barber VP, Fang Y, Klippenstein SJ, Lester MI. Selective deuteration illuminates the importance of tunneling in the unimolecular decay of Criegee intermediates to hydroxyl radical products. Proc Natl Acad Sci U S A 2017; 114:12372-12377. [PMID: 29109292 PMCID: PMC5703325 DOI: 10.1073/pnas.1715014114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ozonolysis of alkenes, an important nonphotolytic source of hydroxyl (OH) radicals in the atmosphere, proceeds through unimolecular decay of Criegee intermediates. Here, we report a large kinetic isotope effect associated with the rate-limiting hydrogen-transfer step that releases OH radicals for a prototypical Criegee intermediate, CH3CHOO. IR excitation of selectively deuterated syn-CD3CHOO is shown to result in deuterium atom transfer and release OD radical products. Vibrational activation of syn-CD3CHOO is coupled with direct time-resolved detection of OD products to measure a 10-fold slower rate of unimolecular decay upon deuteration in the vicinity of the transition state barrier, which is confirmed by microcanonical statistical theory that incorporates quantum mechanical tunneling. The corresponding kinetic isotope effect of ∼10 is attributed primarily to the decreased probability of D-atom vs. H-atom transfer arising from tunneling. Master equation modeling is utilized to compute the thermal unimolecular decay rates for selectively and fully deuterated syn methyl-substituted Criegee intermediates under atmospheric conditions. At 298 K (1 atm), tunneling is predicted to enhance the thermal decay rate of syn-CH3CHOO compared with the deuterated species, giving rise to a significant kinetic isotope effect of ∼50.
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Affiliation(s)
- Amy M Green
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
| | - Victoria P Barber
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
| | - Yi Fang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323;
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167
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Würmel J, Simmie JM. H-Atom Abstraction Reactions by Ground-State Ozone from Saturated Oxygenates. J Phys Chem A 2017; 121:8053-8060. [DOI: 10.1021/acs.jpca.7b07760] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Würmel
- Galway Mayo Institute of Technology, Galway H91 T8NW, Ireland
| | - J. M. Simmie
- School
of Chemistry, National University of Ireland, Galway H91 TK33, Ireland
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168
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Xu K, Wang W, Wei W, Feng W, Sun Q, Li P. Insights into the Reaction Mechanism of Criegee Intermediate CH2OO with Methane and Implications for the Formation of Methanol. J Phys Chem A 2017; 121:7236-7245. [DOI: 10.1021/acs.jpca.7b05858] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kaining Xu
- Key
Laboratory of Life-Organic Analysis, School of Chemistry and Chemical
Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Weihua Wang
- Key
Laboratory of Life-Organic Analysis, School of Chemistry and Chemical
Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Wenjing Wei
- Key
Laboratory of Life-Organic Analysis, School of Chemistry and Chemical
Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Wenling Feng
- Key
Laboratory of Life-Organic Analysis, School of Chemistry and Chemical
Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Qiao Sun
- Collaborative
Innovation Center of Radiation Medicine of Jiangsu Higher Education
Institutions, School for Radiological and Interdisciplinary Sciences, Soochow University, Suzhou 215123, P. R. China
| | - Ping Li
- Key
Laboratory of Life-Organic Analysis, School of Chemistry and Chemical
Engineering, Qufu Normal University, Qufu 273165, P. R. China
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169
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Iyer S, He X, Hyttinen N, Kurtén T, Rissanen MP. Computational and Experimental Investigation of the Detection of HO 2 Radical and the Products of Its Reaction with Cyclohexene Ozonolysis Derived RO 2 Radicals by an Iodide-Based Chemical Ionization Mass Spectrometer. J Phys Chem A 2017; 121:6778-6789. [PMID: 28796517 DOI: 10.1021/acs.jpca.7b01588] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The HO2 radical is an important atmospheric molecule that can potentially influence the termination of autoxidation processes of volatile organic compounds (VOCs) that lead to the formation of highly oxygenated multifunctional compounds (HOMs). In this work, we demonstrate the direct detection of the HO2 radical using an iodide-based chemical ionization mass spectrometer (iodide-CIMS). Expanding on the previously established correlation between molecule-iodide binding enthalpy and iodide-CIMS instrument sensitivity, the experimental detection of the HO2 radical was preceded by the quantum chemical calculation of the HO2*I- cluster (PBE/aug-cc-pVTZ-PP level), which showed a reasonably strong binding enthalpy of 21.60 kcal/mol. Cyclohexene ozonolysis intermediates and closed-shell products were next detected by the iodide-CIMS. The ozone-initiated cyclohexene oxidation mechanism was perturbed by the introduction of the HO2 radical, leading to the formation of closed-shell hydroperoxides. The experimental investigation once again followed the initial computational molecule-iodide binding enthalpy calculations. The quantum chemical calculations were performed at the PBE/aug-cc-pVTZ-PP level for radicals and DLPNO-CCSD(T)/def2-QZVPP//PBE/aug-cc-pVTZ-PP level for the closed-shell products. A comparison between the iodide-CIMS and nitrate-CIMS spectra with identical measurement steps revealed that the iodide-CIMS was able to detect the low-oxidized (O/C ratio 0.5 and 0.66) cyclohexene ozonolysis monomer products more efficiently than nitrate-CIMS. Higher-oxidized monomers (O/C ratio 1 to 1.5) were detected equally well by both methods. An investigation of dimers showed that both iodide- and nitrate-CIMS were able to detect the dimer compositions possibly formed from reactions between the peroxy radical monomers considered in this study. Additionally, iodide-CIMS detected organic ions that were formed by a previously suggested mechanism of dehydroxylation of peroxy acids (and deoxygenation of acyl peroxy radicals) by H2O*I- clusters. These mechanisms were computationally verified.
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Affiliation(s)
- Siddharth Iyer
- Department of Chemistry, and ‡Department of Physics, University of Helsinki , Helsinki, 00100, Finland
| | - Xucheng He
- Department of Chemistry, and ‡Department of Physics, University of Helsinki , Helsinki, 00100, Finland
| | - Noora Hyttinen
- Department of Chemistry, and ‡Department of Physics, University of Helsinki , Helsinki, 00100, Finland
| | - Theo Kurtén
- Department of Chemistry, and ‡Department of Physics, University of Helsinki , Helsinki, 00100, Finland
| | - Matti P Rissanen
- Department of Chemistry, and ‡Department of Physics, University of Helsinki , Helsinki, 00100, Finland
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170
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Vereecken L, Nguyen HMT. Theoretical Study of the Reaction of Carbonyl Oxide with Nitrogen Dioxide: CH2
OO + NO2. INT J CHEM KINET 2017. [DOI: 10.1002/kin.21112] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- L. Vereecken
- Institute for Tropospheric Chemistry; Forschungszentrum Jülich GmbH; 52428 Jülich Germany
| | - H. M. T. Nguyen
- Faculty of Chemistry and Center for Computational Science; Hanoi National University of Education; Hanoi Vietnam
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171
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Bhuvaneswari R, Sandhiya L, Senthilkumar K. Theoretical Investigations on the Mechanism and Kinetics of OH Radical Initiated Reactions of Monochloroacetic Acid. J Phys Chem A 2017; 121:6028-6035. [PMID: 28719205 DOI: 10.1021/acs.jpca.7b03760] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation mechanism of monochloroacetic acid (CH2ClCOOH) by OH radical has been systematically investigated employing quantum mechanical methods coupled with kinetic calculation using canonical variational transition state theory. Three distinct transition states were identified for the titled reaction, two corresponding to the hydrogen atom abstraction and one corresponding to the chlorine atom abstraction. The rate constants of the titled reactions are computed over the temperature range 278-350 K, and the branching ratios calculated for the hydrogen atom abstraction from the -C(O)OH site and the -CH2Cl site are 25 and 75%, respectively, at 298 K. The computed branching ratio indicates that the kinetically favorable reaction is the hydrogen atom abstraction from the -CH2Cl site resulting in the formation of CHClC(O)OH radical, which further undergoes secondary reaction with O2 and other atmospheric species. The calculated overall rate constant for the hydrogen atom abstraction reactions is in consistent with the reported experimental rate constant. The atmospheric lifetime of CH2ClCOOH is found to be around 18 days.
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Affiliation(s)
- R Bhuvaneswari
- Department of Physics, Bharathiar University, Coimbatore - 641 046, Tamil Nadu, India
| | - L Sandhiya
- Department of Physics, Bharathiar University, Coimbatore - 641 046, Tamil Nadu, India
| | - K Senthilkumar
- Department of Physics, Bharathiar University, Coimbatore - 641 046, Tamil Nadu, India
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172
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Pidko EA. Toward the Balance between the Reductionist and Systems Approaches in Computational Catalysis: Model versus Method Accuracy for the Description of Catalytic Systems. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00290] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Evgeny A. Pidko
- Theoretical Chemistry Group, ITMO University, Lomonosova str. 9, St. Petersburg 191002, Russia
- Inorganic Materials
Chemistry Group, Schuit Institute of Catalysis, and Institute for Complex Molecular Systems, Eindhoven University of Technology,
P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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173
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Spectroscopic Characterization of the Reaction Products between the Criegee Intermediate CH2
OO and HCl. Chemphyschem 2017; 18:1860-1863. [DOI: 10.1002/cphc.201700446] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Indexed: 11/07/2022]
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174
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Affiliation(s)
- Rommel B. Viana
- Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, Brazil
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175
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Taatjes CA. Criegee Intermediates: What Direct Production and Detection Can Teach Us About Reactions of Carbonyl Oxides. Annu Rev Phys Chem 2017; 68:183-207. [DOI: 10.1146/annurev-physchem-052516-050739] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Craig A. Taatjes
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551-0969
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176
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Fang Y, Barber VP, Klippenstein SJ, McCoy AB, Lester MI. Tunneling effects in the unimolecular decay of (CH3)2COO Criegee intermediates to OH radical products. J Chem Phys 2017; 146:134307. [DOI: 10.1063/1.4979297] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yi Fang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323,
USA
| | - Victoria P. Barber
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323,
USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division,
Argonne National Laboratory, Argonne, Illinois 60439,
USA
| | - Anne B. McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323,
USA
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177
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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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178
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Akbulatov S, Boulatov R. Experimental Polymer Mechanochemistry and its Interpretational Frameworks. Chemphyschem 2017; 18:1422-1450. [PMID: 28256793 DOI: 10.1002/cphc.201601354] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 12/15/2022]
Abstract
Polymer mechanochemistry is an emerging field at the interface of chemistry, materials science, physics and engineering. It aims at understanding and exploiting unique reactivities of polymer chains confined to highly non-equilibrium stretched geometries by interactions with their surroundings. Macromolecular chains or their segments become stretched in bulk polymers under mechanical loads or when polymer solutions are sonicated or flow rapidly through abrupt contractions. An increasing amount of empirical data suggests that mechanochemical phenomena are widespread wherever polymers are used. In the past decade, empirical mechanochemistry has progressed enormously, from studying fragmentations of commodity polymers by simple backbone homolysis to demonstrations of self-strengthening and stress-reporting materials and mechanochemical cascades using purposefully designed monomers. This progress has not yet been matched by the development of conceptual frameworks within which to rationalize, systematize and generalize empirical mechanochemical observations. As a result, mechanistic and/or quantitative understanding of mechanochemical phenomena remains, with few exceptions, tentative. In this review we aim at systematizing reported macroscopic manifestations of polymer mechanochemistry, and critically assessing the interpretational framework that underlies their molecular rationalizations from a physical chemist's perspective. We propose a hierarchy of mechanochemical phenomena which may guide the development of multiscale models of mechanochemical reactivity to match the breadth and utility of the Eyring equation of chemical kinetics. We discuss the limitations of the approaches to quantifying and validating mechanochemical reactivity, with particular focus on sonicated polymer solutions, in order to identify outstanding questions that need to be solved for polymer mechanochemistry to become a rigorous, quantitative field. We conclude by proposing 7 problems whose solution may have a disproportionate impact on the development of polymer mechanochemistry.
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Affiliation(s)
- Sergey Akbulatov
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
| | - Roman Boulatov
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
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179
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Bai FY, Lv S, Ma Y, Liu CY, He CF, Pan XM. Understanding the insight into the mechanisms and dynamics of the Cl-initiated oxidation of (CH 3) 3CC(O)X and the subsequent reactions in the presence of NO and O 2 (X = F, Cl, and Br). CHEMOSPHERE 2017; 171:49-56. [PMID: 28002766 DOI: 10.1016/j.chemosphere.2016.12.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
In this work, the density functional and high-level ab initio theories are adopted to investigate the mechanisms and kinetics of reaction of (CH3)3CC(O)X (X = F, Cl, and Br) with atomic chlorine. Rate coefficients for the reactions of chlorine atom with (CH3)3CC(O)F (k1), (CH3)3CC(O)Cl (k2), and (CH3)3CC(O)Br (k3) are calculated using canonical variational transition state theory coupled with small curvature tunneling method over a wide range of temperatures from 250 to 1000 K. The dynamic calculations are performed by the variational transition state theory with the interpolated single-point energies method at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of theory. Computed rate constant is in good line with the available experimental value. The rate constants for the title reactions are in this order: k1<k2<k3, suggesting that the effect of halogen substitution on the mechanisms and dynamics is different. The subsequent and secondary reactions for the hydrogen abstraction intermediates are studied involving NO and O2 molecules in the atmosphere. The atmospheric lifetime and global warming potential (GWP) of (CH3)3CC(O)X (X = F, Cl, and Br) are estimated, and it shows that (CH3)3CC(O)F have larger GWP value than that of (CH3)3CC(O)Cl and (CH3)3CC(O)Br. Due to the presence of Cl and Br atoms, the environmental impact of (CH3)3CC(O)Cl and (CH3)3CC(O)Br may be given more concerns.
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Affiliation(s)
- Feng-Yang Bai
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Shuang Lv
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Yuan Ma
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Chun-Yu Liu
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Chun-Fang He
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Xiu-Mei Pan
- Institute of Functional Material Chemistry, National & Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University, 130024, Changchun, People's Republic of China.
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180
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Elakiya C, Shankar R, Vijayakumar S, Kolandaivel P. A theoretical study on the reaction mechanism and kinetics of allyl alcohol (CH2 = CHCH2OH) with ozone (O3) in the atmosphere. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1292012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- C. Elakiya
- Department of Physics, Bharathiar University, Coimbatore, India
| | - R. Shankar
- Department of Physics, Bharathiar University, Coimbatore, India
| | - S. Vijayakumar
- Department of Medical Physics, Bharathiar University, Coimbatore, India
| | - P. Kolandaivel
- Department of Physics, Bharathiar University, Coimbatore, India
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181
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Xie HB, Ma F, Yu Q, He N, Chen J. Computational Study of the Reactions of Chlorine Radicals with Atmospheric Organic Compounds Featuring NHx–π-Bond (x = 1, 2) Structures. J Phys Chem A 2017; 121:1657-1665. [DOI: 10.1021/acs.jpca.6b11418] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hong-Bin Xie
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Fangfang Ma
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Qi Yu
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Ning He
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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182
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Smith MC, Chao W, Kumar M, Francisco JS, Takahashi K, Lin JJM. Temperature-Dependent Rate Coefficients for the Reaction of CH2OO with Hydrogen Sulfide. J Phys Chem A 2017; 121:938-945. [DOI: 10.1021/acs.jpca.6b12303] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mica C. Smith
- Institute
of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
| | - Wen Chao
- Institute
of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
- Department
of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Manoj Kumar
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Joseph S. Francisco
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Kaito Takahashi
- Institute
of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
| | - Jim Jr-Min Lin
- Institute
of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
- Department
of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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183
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Lv C, Du L, Tang S, Tsona NT, Liu S, Zhao H, Wang W. Matrix isolation study of the early intermediates in the ozonolysis of selected vinyl ethers. RSC Adv 2017. [DOI: 10.1039/c7ra01011g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Criegee mechanism of the ozonolysis reaction of vinyl ethers has been observed by matrix isolation FTIR spectroscopy.
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Affiliation(s)
- Chen Lv
- Environment Research Institute
- Shandong University
- China
| | - Lin Du
- Environment Research Institute
- Shandong University
- China
| | - Shanshan Tang
- Environment Research Institute
- Shandong University
- China
| | | | - Shijie Liu
- Environment Research Institute
- Shandong University
- China
| | - Hailiang Zhao
- Environment Research Institute
- Shandong University
- China
| | - Wenxing Wang
- Environment Research Institute
- Shandong University
- China
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184
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Yin C, Takahashi K. How does substitution affect the unimolecular reaction rates of Criegee intermediates? Phys Chem Chem Phys 2017; 19:12075-12084. [DOI: 10.1039/c7cp01091e] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unimolecular reaction rates of Criegee intermediates show substitution effect.
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Affiliation(s)
- Cangtao Yin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei
- Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei
- Taiwan
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185
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Decker ZCJ, Au K, Vereecken L, Sheps L. Direct experimental probing and theoretical analysis of the reaction between the simplest Criegee intermediate CH2OO and isoprene. Phys Chem Chem Phys 2017; 19:8541-8551. [DOI: 10.1039/c6cp08602k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of CH2OO with isoprene, the highest-emitted unsaturated compound on Earth, is similar to reactions with small singly-unsaturated alkenes.
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Affiliation(s)
- Z. C. J. Decker
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - K. Au
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - L. Vereecken
- Institute for Energy and Climate Research
- Forschungszentrum Jülich GmbH
- 52428 Jülich
- Germany
| | - L. Sheps
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
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186
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Liu Y, Liu F, Liu S, Dai D, Dong W, Yang X. A kinetic study of the CH2OO Criegee intermediate reaction with SO2, (H2O)2, CH2I2 and I atoms using OH laser induced fluorescence. Phys Chem Chem Phys 2017; 19:20786-20794. [DOI: 10.1039/c7cp04336h] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The OH laser induced fluorescence method was used to study the kinetics of CH2OO reacting with SO2, (H2O)2, CH2I2 and I atoms.
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Affiliation(s)
- Yiqiang Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Fenghua Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Siyue Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Dongxu Dai
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Wenrui Dong
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
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187
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Launder AM, Turney JM, Agarwal J, Schaefer HF. Ethylperoxy radical: approaching spectroscopic accuracy via coupled-cluster theory. Phys Chem Chem Phys 2017; 19:15715-15723. [DOI: 10.1039/c7cp02795h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly reliable ground and excited state properties of the conformers of ethylperoxy radical are predicted using coupled-cluster theory. This research has implications for future characterization of intermediates in tropospheric and low-temperature combustion processes.
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Affiliation(s)
- Andrew M. Launder
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- USA
| | - Justin M. Turney
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- USA
| | - Jay Agarwal
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- USA
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry
- University of Georgia
- Athens
- USA
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188
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Finlayson-Pitts BJ. Introductory lecture: atmospheric chemistry in the Anthropocene. Faraday Discuss 2017; 200:11-58. [DOI: 10.1039/c7fd00161d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The term “Anthropocene” was coined by Professor Paul Crutzen in 2000 to describe an unprecedented era in which anthropogenic activities are impacting planet Earth on a global scale. Greatly increased emissions into the atmosphere, reflecting the advent of the Industrial Revolution, have caused significant changes in both the lower and upper atmosphere. Atmospheric reactions of the anthropogenic emissions and of those with biogenic compounds have significant impacts on human health, visibility, climate and weather. Two activities that have had particularly large impacts on the troposphere are fossil fuel combustion and agriculture, both associated with a burgeoning population. Emissions are also changing due to alterations in land use. This paper describes some of the tropospheric chemistry associated with the Anthropocene, with emphasis on areas having large uncertainties. These include heterogeneous chemistry such as those of oxides of nitrogen and the neonicotinoid pesticides, reactions at liquid interfaces, organic oxidations and particle formation, the role of sulfur compounds in the Anthropocene and biogenic–anthropogenic interactions. A clear and quantitative understanding of the connections between emissions, reactions, deposition and atmospheric composition is central to developing appropriate cost-effective strategies for minimizing the impacts of anthropogenic activities. The evolving nature of emissions in the Anthropocene places atmospheric chemistry at the fulcrum of determining human health and welfare in the future.
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189
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Taatjes CA, Liu F, Rotavera B, Kumar M, Caravan R, Osborn DL, Thompson WH, Lester MI. Hydroxyacetone Production From C3 Criegee Intermediates. J Phys Chem A 2016; 121:16-23. [DOI: 10.1021/acs.jpca.6b07712] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Craig A. Taatjes
- Combustion Research
Facility, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Fang Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Brandon Rotavera
- Combustion Research
Facility, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Manoj Kumar
- Department of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588-0304, United States
| | - Rebecca Caravan
- Combustion Research
Facility, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - David L. Osborn
- Combustion Research
Facility, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Ward H. Thompson
- Department
of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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190
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Long B, Tan XF, Bao JL, Wang DM, Long ZW. Theoretical Study of the Reaction Mechanism and Kinetics of HO2with XCHO (X = F, Cl). INT J CHEM KINET 2016. [DOI: 10.1002/kin.21062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Bo Long
- College of Computer and Information Engineering; Guizhou MinZu University; Guiyang 550025 People's Republic of China
| | - Xing-Feng Tan
- College of Computer and Information Engineering; Guizhou MinZu University; Guiyang 550025 People's Republic of China
| | - Junwei Lucas Bao
- Department of Chemistry; Chemical Theory Center, and Supercomputing Institute; University of Minnesota; Minneapolis MN 55455
| | - Ding-Mei Wang
- Department of Physics; Guizhou University; Guiyang 550025 People's Republic of China
| | - Zheng-Wen Long
- Department of Physics; Guizhou University; Guiyang 550025 People's Republic of China
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191
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Karton A. How reliable is DFT in predicting relative energies of polycyclic aromatic hydrocarbon isomers? comparison of functionals from different rungs of jacob's ladder. J Comput Chem 2016; 38:370-382. [DOI: 10.1002/jcc.24669] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Amir Karton
- School of Chemistry and BiochemistryThe University of Western AustraliaPerthWestern Australia 6009 Australia
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192
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Anglada JM, Crehuet R, Francisco JS. The Stability of α-Hydroperoxyalkyl Radicals. Chemistry 2016; 22:18092-18100. [PMID: 27808436 DOI: 10.1002/chem.201604499] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Indexed: 11/08/2022]
Abstract
High-level ab initio and Born-Oppenheimer molecular dynamic calculations have been carried out on a series of hydroperoxyalkyl (α-QOOH) radicals with the aim of investigating the stability and unimolecular decomposition mechanism into QO+OH of these species. Dissociation was shown to take place through rotation of the C-O(OH) bond rather than through elongation of the CO-OH bond. Through the C-O(OH) rotation, the unpaired electron of the radical overlaps with the electron density on the O-OH bond, and from this overlap the C=O π bond forms and the O-OH bond breaks spontaneously. The CH2 OOH, CH(CH3 )OOH, CH(OH)OOH, and α-hydroperoxycycloheptadienyl radical were found to decompose spontaneously, but the CH(CHO)OOH has a decomposition energy barrier of 5.95 kcal mol-1 owing to its steric and electronic features. The systems studied in this work provide the first insights into how structural and electronic effects govern the stabilizing influence on elusive α-QOOH radicals.
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Affiliation(s)
- Josep M Anglada
- College of Arts and Sciences, University of Nebraska-Lincoln, 1223 Oldfather Hall, Lincoln, NE, 68588-0312, United States.,Departament de Química Biològica i Modelització Molecular, IQAC-CSIC, c/Jordi Girona 18, 08034, Barcelona, Spain
| | - Ramon Crehuet
- Departament de Química Biològica i Modelització Molecular, IQAC-CSIC, c/Jordi Girona 18, 08034, Barcelona, Spain
| | - Joseph S Francisco
- College of Arts and Sciences, University of Nebraska-Lincoln, 1223 Oldfather Hall, Lincoln, NE, 68588-0312, United States
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193
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Borduas N, Abbatt JPD, Murphy JG, So S, da Silva G. Gas-Phase Mechanisms of the Reactions of Reduced Organic Nitrogen Compounds with OH Radicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:11723-11734. [PMID: 27690404 DOI: 10.1021/acs.est.6b03797] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Research on the fate of reduced organic nitrogen compounds in the atmosphere has gained momentum since the identification of their crucial role in particle nucleation and the scale up of carbon capture and storage technology which employs amine-based solvents. Reduced organic nitrogen compounds have strikingly different lifetimes against OH radicals, from hours for amines to days for amides to years for isocyanates, highlighting unique functional group reactivity. In this work, we use ab initio methods to investigate the gas-phase mechanisms governing the reactions of amines, amides, isocyanates and carbamates with OH radicals. We determine that N-H abstraction is only a viable mechanistic pathway for amines and we identify a reactive pathway in amides, the formyl C-H abstraction, not currently considered in structure-activity relationship (SAR) models. We then use our acquired mechanistic knowledge and tabulated literature experimental rate coefficients to calculate SAR factors for reduced organic nitrogen compounds. These proposed SAR factors are an improvement over existing SAR models because they predict the experimental rate coefficients of amines, amides, isocyanates, isothiocyanates, carbamates and thiocarbamates with OH radicals within a factor of 2, but more importantly because they are based on a sound fundamental mechanistic understanding of their reactivity.
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Affiliation(s)
- Nadine Borduas
- Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Jennifer G Murphy
- Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Sui So
- Chemical and Biomolecular Engineering, University of Melbourne , Victoria 3010, Australia
| | - Gabriel da Silva
- Chemical and Biomolecular Engineering, University of Melbourne , Victoria 3010, Australia
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194
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Long B, Bao JL, Truhlar DG. Atmospheric Chemistry of Criegee Intermediates: Unimolecular Reactions and Reactions with Water. J Am Chem Soc 2016; 138:14409-14422. [PMID: 27682870 DOI: 10.1021/jacs.6b08655] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Criegee intermediates are produced in the ozonolysis of unsaturated hydrocarbons in the troposphere, and understanding their fate is a prerequisite to modeling climate-controlling atmospheric aerosol formation. Although some experimental and theoretical rate data are available, they are incomplete and partially inconsistent, and they do not cover the tropospheric temperature range. Here, we report quantum chemical rate constants for the reactions of stabilized formaldehyde oxide (CH2OO) and acetaldehyde oxide (syn-CH3CHOO and anti-CH3CHOO) with H2O and for their unimolecular reactions. Our results are obtained by combining post-CCSD(T) electronic structure benchmarks, validated density functional theory potential energy surfaces, and multipath variational transition state theory with multidimensional tunneling, coupled-torsions anharmonicity, and high-frequency anharmonicity. We consider two different types of reaction mechanisms for the bimolecular reactions, namely, (i) addition-coupled hydrogen transfer and (ii) double hydrogen atom transfer (DHAT). First, we show that the MN15-L exchange-correlation functional has kJ/mol accuracy for the CH2OO + H2O and syn-CH3CHOO + H2O reactions. Then we show that, due to tunneling, the DHAT mechanism is especially important in the syn-CH3CHOO + H2O reaction. We show that the dominant pathways for reactions of Criegee intermediates depend on altitude. The results we obtain eliminate the discrepancy between experiment and theory under those conditions where experimental results are available, and we make predictions for the full range of temperatures and pressures encountered in the troposphere and stratosphere. The present results are an important cog in clarifying the atmospheric fate and oxidation processes of Criegee intermediates, and they also show how theoretical methods can provide reliable rate data for complex atmospheric processes.
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Affiliation(s)
- Bo Long
- College of Information Engineering, Guizhou Minzu University , Guiyang 550025, China.,Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | - Junwei Lucas Bao
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
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195
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Mackenzie-Rae FA, Karton A, Saunders SM. Computational investigation into the gas-phase ozonolysis of the conjugated monoterpene α-phellandrene. Phys Chem Chem Phys 2016; 18:27991-28002. [PMID: 27711539 DOI: 10.1039/c6cp04695a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Reaction with ozone is a major atmospheric sink for α-phellandrene, a monoterpene found in both indoor and outdoor environments, however experimental literature concerning the reaction is scarce. In this study, high-level G4(MP2) quantum chemical calculations are used to theoretically characterise the reaction of ozone with both double bonds in α-phellandrene for the first time. Results show that addition of ozone to the least substituted double bond in the conjugated system is preferred. Following addition, thermal and chemically activated unimolecular reactions, including the so-called hydroperoxide and ester or 'hot' acid channels, and internal cyclisation reactions, are characterised to major first generation products. Conjugation present in α-phellandrene allows two favourable Criegee intermediate reaction pathways to proceed that have not previously been considered in the literature; namely a 1,6-allyl resonance stabilised hydrogen shift and intramolecular dioxirane isomerisation to an epoxide. These channels are expected to play an important role alongside conventional routes in the ozonolysis of a-phellandrene. Computational characterisation of the potential energy surface thus provides insight into this previously unstudied system, and will aid future mechanism development and experimental interpretation involving α-phellandrene and structurally similar species, to which the results are expected to extend.
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Affiliation(s)
- F A Mackenzie-Rae
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009, Australia.
| | - A Karton
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009, Australia.
| | - S M Saunders
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009, Australia.
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196
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Nguyen TL, McCaslin L, McCarthy MC, Stanton JF. Communication: Thermal unimolecular decomposition of syn-CH3CHOO: A kinetic study. J Chem Phys 2016; 145:131102. [DOI: 10.1063/1.4964393] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Thanh Lam Nguyen
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Laura McCaslin
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA
| | - John F. Stanton
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA
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197
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Oliveira AM, Lehman JH, McCoy AB, Lineberger WC. Photoelectron spectroscopy of the hydroxymethoxide anion, H 2C(OH)O . J Chem Phys 2016; 145:124317. [PMID: 27782682 DOI: 10.1063/1.4963225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the negative ion photoelectron spectroscopy of the hydroxymethoxide anion, H2C(OH)O-. The photoelectron spectra show that 3.49 eV photodetachment produces two distinct electronic states of the neutral hydroxymethoxy radical (H2C(OH)O⋅). The H2C(OH)O⋅ ground state (X̃ 2A) photoelectron spectrum exhibits a vibrational progression consisting primarily of the OCO symmetric and asymmetric stretches, the OCO bend, as well as combination bands involving these modes with other, lower frequency modes. A high-resolution photoelectron spectrum aids in the assignment of several vibrational frequencies of the neutral H2C(OH)O⋅ radical, including an experimental determination of the H2C(OH)O⋅ 2ν12 overtone of the H-OCO torsional vibration as 220(10) cm-1. The electron affinity of H2C(OH)O⋅ is determined to be 2.220(2) eV. The low-lying à 2A excited state is also observed, with a spectrum that peaks ∼0.8 eV above the X̃ 2A state origin. The à 2A state photoelectron spectrum is a broad, partially resolved band. Quantum chemical calculations and photoelectron simulations aid in the interpretation of the photoelectron spectra. In addition, the gas phase acidity of methanediol is calculated to be 366(2) kcal mol-1, which results in an OH bond dissociation energy, D0(H2C(OH)O-H), of 104(2) kcal mol-1, using the experimentally determined electron affinity of the hydroxymethoxy radical.
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Affiliation(s)
- Allan M Oliveira
- JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Julia H Lehman
- JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - W Carl Lineberger
- JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
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198
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Li H, Kidwell NM, Wang X, Bowman JM, Lester MI. Velocity map imaging of OH radical products from IR activated (CH3)2COO Criegee intermediates. J Chem Phys 2016; 145:104307. [DOI: 10.1063/1.4962361] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hongwei Li
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Nathanael M. Kidwell
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Xiaohong Wang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Joel M. Bowman
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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199
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Kovacevic G, Sabljic A. Atmospheric oxidation of hexachlorobenzene: New global source of pentachlorophenol. CHEMOSPHERE 2016; 159:488-495. [PMID: 27341152 DOI: 10.1016/j.chemosphere.2016.06.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 06/01/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
Hexachlorobenzene is highly persistent, bioaccumulative, toxic and globally distributed, a model persistent organic pollutant. The major atmospheric removal process for hexachlorobenzene is its oxidation by hydroxyl radicals. Unfortunately, there is no information on the reaction mechanism of this important atmospheric process and the respective degradation rates were measured in a narrow temperature range not of environmental relevance. Thus, the geometries and energies of all stationary points significant for the atmospheric oxidation of hexachlorobenzene are optimized using MP2/6-311G(d,p) method. Furthermore, the single point energies were calculated with G3 method on the optimized minima and transition-states. It was demonstrated for the first time that the addition of hydroxyl radicals to hexachlorobenzene proceeds indirectly, via a prereaction complex. In the prereaction complex the hydroxyl radical is almost perpendicular to the aromatic ring while oxygen is pointing to its center. In contrast, in the transition state it is nearly parallel with the aromatic ring. The reliable rate constants are calculated for the first time for the atmospheric oxidation of hexachlorobenzene for all environmentally relevant temperatures. It was also demonstrated for the first time that pentachlorophenol is the major stable product in the addition of hydroxyl radicals to hexachlorobenzene and that atmosphere seems to be a new global secondary source of pentachlorophenol.
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Affiliation(s)
- Goran Kovacevic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Croatia
| | - Aleksandar Sabljic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Croatia.
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200
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Křůmal K, Mikuška P, Večeřová K, Urban O, Pallozzi E, Večeřa Z. WITHDRAWN: Wet effluent diffusion denuder: The tool for determination of monoterpenes in forest. Talanta 2016; 158:192. [PMID: 27343594 DOI: 10.1016/j.talanta.2015.12.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.talanta.2016.03.032. The duplicate article has therefore been withdrawn.The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Kamil Křůmal
- Institute of Analytical Chemistry of the CAS, v. v. i., Veveří 97, 60200 Brno, Czech Republic.
| | - Pavel Mikuška
- Institute of Analytical Chemistry of the CAS, v. v. i., Veveří 97, 60200 Brno, Czech Republic
| | - Kristýna Večeřová
- Global Change Research Centre of the CAS, v. v. i., Bělidla 986/4a, 60300 Brno, Czech Republic
| | - Otmar Urban
- Global Change Research Centre of the CAS, v. v. i., Bělidla 986/4a, 60300 Brno, Czech Republic
| | - Emanuele Pallozzi
- National Research Council, Institute of Agroenvironmental and Forest Biology, Via Guglielmo Marconi 2, 05010 Porano, Italy
| | - Zbyněk Večeřa
- Institute of Analytical Chemistry of the CAS, v. v. i., Veveří 97, 60200 Brno, Czech Republic
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