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Viegas LP. A Multiconformational Transition State Theory Approach to OH Tropospheric Degradation of Fluorotelomer Aldehydes. Chemphyschem 2023; 24:e202300259. [PMID: 37326576 DOI: 10.1002/cphc.202300259] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/17/2023]
Abstract
Experimental work on the OH-initiated oxidation reactions of fluorotelomer aldehydes (FTALs) strongly suggests that the respective rate coefficients do not depend on the size of the Cx F2x+1 fluoroalkyl chain. FTALs hence represent a challenging test to our multiconformer transition state theory (MC-TST) protocol based on constrained transition state randomization (CTSR), since the calculated rate coefficients should not show significant variations with increasing values of x ${x}$ . In this work we apply the MC-TST/CTSR protocol to thex = 2 , 3 ${x={\rm 2,3}}$ cases and calculate both rate coefficients at 298.15 K with a value ofk = ( 2 . 4 ± 1 . 4 ) × 10 - 12 ${k=(2.4\pm 1.4)\times {10}^{-12}}$ cm3 molecule-1 s-1 , practically coincident with the recommended experimental value of kexp =( 2 . 8 ± 1 . 4 ) × 10 - 12 ${(2.8\pm 1.4)\times {10}^{-12}}$ cm3 molecule-1 s-1 . We also show that the use of tunneling corrections based on improved semiclassical TST is critical in obtaining Arrhenius-Kooij curves with a correct behavior at lower temperatures.
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Affiliation(s)
- Luís P Viegas
- Coimbra Chemistry Centre-Institute of Molecular Sciences (CQC-IMS), Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal
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2
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Abstract
Reactivity scales are useful research tools for chemists, both experimental and computational. However, to determine the reactivity of a single molecule, multiple measurements need to be carried out, which is a time-consuming and resource-intensive task. In this Tutorial Review, we present alternative approaches for the efficient generation of quantitative structure-reactivity relationships that are based on quantum chemistry, supervised learning, and uncertainty quantification. First published in 2002, we observe a tendency for these relationships to become not only more predictive but also more interpretable over time.
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Affiliation(s)
- Maike Vahl
- Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany.
| | - Jonny Proppe
- Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany.
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3
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Viegas LP. Gas-phase OH-oxidation of 2-butanethiol: Multiconformer transition state theory rate constant with constrained transition state randomization. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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4
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Li J, Wang L, Wang L. Computational Study on the Reaction of β-Hydroxyethylperoxy Radical with HO 2 and Effects of Water Vapor. J Phys Chem A 2022; 126:2234-2243. [PMID: 35362984 DOI: 10.1021/acs.jpca.1c09009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of β-hydroxyethylperoxy radical (β-HEP) and HO2 with and without water was studied using quantum chemistry and kinetic calculations. The main products are HOCH2CH2OOH and 3O2 for the reaction with and without water, while all other reaction channels can be neglected. The rate coefficients of the reaction follow negative temperature dependence. The pseudo-second-order rate coefficients are 2-4 orders of magnitude smaller for the reaction with saturated water vapor, indicating the negligible contribution of water in this reaction. This is probably also true for other peroxy radicals (except for HO2), indicating that a large part of previous results on the water enhancement of reaction rate coefficients might have overestimated the influence of water.
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Affiliation(s)
- Junjie Li
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Lingyu Wang
- School of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Liming 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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5
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Klippenstein SJ. Spiers Memorial Lecture: theory of unimolecular reactions. Faraday Discuss 2022; 238:11-67. [DOI: 10.1039/d2fd00125j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One hundred years ago, at an earlier Faraday Discussion meeting, Lindemann presented a mechanism that provides the foundation for contemplating the pressure dependence of unimolecular reactions. Since that time, our...
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Viegas LP. Simplified Protocol for the Calculation of Multiconformer Transition State Theory Rate Constants Applied to Tropospheric OH-Initiated Oxidation Reactions. J Phys Chem A 2021; 125:4499-4512. [PMID: 33902279 DOI: 10.1021/acs.jpca.1c00683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical kinetics plays a fundamental role in the understanding and modeling of tropospheric chemical processes, one of the most important being the atmospheric degradation of volatile organic compounds. These potentially harmful molecules are emitted into the troposphere by natural and anthropogenic sources and are chemically removed by undergoing oxidation processes, most frequently initiated by reaction with OH radicals, the atmosphere's "detergent". Obtaining the respective rate constants is therefore of critical importance, with calculations based on transition state theory (TST) often being the preferred choice. However, for molecules with rich conformational variety, a single-conformer method such as lowest-conformer TST is unsuitable while state-of-the-art TST-based methodologies easily become unmanageable. In this Feature Article, the author reviews his own cost-effective protocol for the calculation of bimolecular rate constants of OH-initiated reactions in the high-pressure limit based on multiconformer transition state theory. The protocol, which is easily extendable to other oxidation reactions involving saturated organic molecules, is based on a variety of freeware and open-source software and tested against a series of oxidation reactions of hydrofluoropolyethers, computationally very challenging molecules with potential environmental relevance. The main features, advantages and disadvantages of the protocol are presented, along with an assessment of its predictive utility based on a comparison with experimental rate constants.
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Affiliation(s)
- Luís P Viegas
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Buildings 1630-1632, Aarhus 8000, Denmark
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Viegas LSP, Jensen F. Reactivity of α,ω-Dihydrofluoropolyethers toward OH Predicted by Multiconformer Transition State Theory and the Interacting Quantum Atoms Approach. J Phys Chem A 2020; 124:3460-3470. [PMID: 32242667 DOI: 10.1021/acs.jpca.0c02911] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report rate constants for the tropospheric reaction between the OH radical and α,ω-dihydrofluoropolyethers, which represent a specific class of the hydrofluoropolyethers family with the formula HF2C(OCF2CF2)p(OCF2)qOCF2H. Four cases were considered: p0q2, p0q3, p1q0, and p1q1 (pxqy denoting p = x and q = y) with the calculations performed by a cost-effective protocol developed for bimolecular hydrogen-abstraction reactions. This protocol is based on multiconformer transition state theory and relies on computationally accessible M08-HX/apcseg-2//M08-HX/pcseg-1 calculations. Within the protocol's approximations, the results show that (1) the calculated rate constants are within a factor of five of the experimental results (p1q0 and p1q1) and (2) the chain length and composition have a negligible effect on the rate constants, which is consistent with the experimental work. The interacting quantum atoms energy decomposition scheme is used to analyze the observed trends and extract chemical information related to the imaginary frequencies and barrier heights that are key parameters controlling the reactivity of the reaction. The intramolecular exchange-correlation contributions in the reactants and transition states were found to be the dominating factor.
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Affiliation(s)
- Luı S P Viegas
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Buildings 1630-1632, Aarhus 8000, Denmark
| | - Frank Jensen
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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de Souza Machado G, Martins EM, Baptista L, Bauerfeldt GF. Prediction of Rate Coefficients for the H 2CO + OH → HCO + H 2O Reaction at Combustion, Atmospheric and Interstellar Medium Conditions. J Phys Chem A 2020; 124:2309-2317. [PMID: 32091904 DOI: 10.1021/acs.jpca.9b11690] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite the relevance of the H2CO + OH → HCO + H2O reaction for combustion, atmospheric, and interstellar medium conditions, a large discrepancy on energetic and kinetic data for this reaction is still observed in the previous literature. In this work, this hydrogen abstraction reaction has been investigated at the CCSD(T)/CBS level of theory, suggesting that both the prebarrier complex and saddle point are stabilized in relation to the reactants by 3.31 and 1.35 kcal mol-1, respectively. Moreover, from the Gibbs free energy profile of the reaction coordinate, it has been verified that the formation of the prebarrier complex is endergonic, for temperatures above 550 K. Hence, for temperatures lower than 550 K, the reaction is described by a mechanism consisting of three elementary steps, while for higher temperatures it can be assumed to be an elementary reaction. Finally, the prediction of rate coefficients suggests that unified statistical rate theory best applies to the low temperature regime, while canonical variational rate coefficients better fit experimental data at the high temperature regime.
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Affiliation(s)
- Gladson de Souza Machado
- Instituto de Quı́mica, Universidade Federal Rural do Rio de Janeiro, BR-465 km 7, Seropédica, RJ, 23890-000 Brazil
| | - Eduardo Monteiro Martins
- Departamento de Engenharia Sanitária e do Meio Ambiente, Faculdade de Engenharia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, 20550-900 Brazil
| | - Leonardo Baptista
- Departamento de Quı́mica e Ambiental, Faculdade de Tecnologia, Universidade do Estado do Rio de Janeiro, Rodovia Presidente Dutra km 298, Resende, RJ, 27537-000 Brazil
| | - Glauco F Bauerfeldt
- Instituto de Quı́mica, Universidade Federal Rural do Rio de Janeiro, BR-465 km 7, Seropédica, RJ, 23890-000 Brazil
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Harvey JN, Himo F, Maseras F, Perrin L. Scope and Challenge of Computational Methods for Studying Mechanism and Reactivity in Homogeneous Catalysis. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01537] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Jeremy N. Harvey
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Fahmi Himo
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain
| | - Lionel Perrin
- Univ Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INSA Lyon, ICBMS, CNRS UMR 5246, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne, France
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Viegas LP. Theoretical determination of the OH-initiated oxidation rate constants of $${\alpha ,\omega }$$-dialkoxyfluoropolyethers. Theor Chem Acc 2019. [DOI: 10.1007/s00214-019-2436-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Viegas LP. Multiconformer transition state theory rate constants for the reaction between OH and ‐dimethoxyfluoropolyethers. INT J CHEM KINET 2019. [DOI: 10.1002/kin.21259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Luís P. Viegas
- Aarhus Institute of Advanced StudiesAarhus UniversityAarhus Denmark
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12
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Tuñón I, Williams IH. The transition state and cognate concepts. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2019. [DOI: 10.1016/bs.apoc.2019.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Viegas LP. Exploring the Reactivity of Hydrofluoropolyethers toward OH through a Cost-Effective Protocol for Calculating Multiconformer Transition State Theory Rate Constants. J Phys Chem A 2018; 122:9721-9732. [DOI: 10.1021/acs.jpca.8b08970] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luís P. Viegas
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Buildings 1630-1632, Aarhus 8000, Denmark
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Vijayakumar S, Rajakumar B. An Exprimental and Computational Study on the Cl Atom Initiated Photo-Oxidization Reactions of Butenes in the Gas Phase. J Phys Chem A 2017; 121:5487-5499. [PMID: 28682612 DOI: 10.1021/acs.jpca.7b04783] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Temperature-dependent rate coefficients for the reactions of Cl atoms with trans-2-butene and isobutene were measured over the temperature range of 263-363 K using relative rate technique with reference to 1,3-butadiene, isoprene, and 1-pentene. The measured rate coefficients for the reactions of Cl atoms with isobutene and trans-2-butene are kR1298K= (3.43 ± 0.11) × 10-10 and kR2298K = (3.20 ± 0.04) × 10-10 cm3 molecule-1 s-1, respectively, at 298 K and 760 torr. Measured rate coefficients were used to fit the Arrhenius equations, which are obtained to be kR1-Exp269-363K = (4.99 ± 0.42) × 10-11 exp[(584 ± 26)/T] and kR2-Exp269-363K = (1.11 ± 0.3) × 10-10 exp[(291 ± 88)/T] cm3 molecule-1 s-1 for isobutene and trans-2-butene, respectively. To understand the reaction mechanism, estimate the contribution of each reaction site, and to complement our experimental results, computational studies were also performed. Canonical variational transition state theory with small curvature tunneling in combination with MP2/6-31G(d), MP2/6-31G(d,p), MP2/6-31+G(d,p), CCSD(T)/cc-pvdz, and QCISD(T)/cc-pvdz level of theories were used to calculate the temperature-dependent rate coefficients over the temperature range of 200-400 K. The effective lifetimes, thermodynamic parameters, and atmospheric implications of the test molecules were also estimated.
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Affiliation(s)
- S Vijayakumar
- Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India
| | - B Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India
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Assessment of theoretical methods for the study of hydrogen abstraction kinetics of global warming gas species during their degradation and byproduct formation (IUPAC Technical Report). PURE APPL CHEM 2013. [DOI: 10.1351/pac-rep-10-02-38] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Global climate change is a major concern as it leads to an increase in the
average temperature of the earth’s atmosphere. The existence and
persistence of some gaseous species in the atmosphere contribute to global
warming. Experimental techniques are used to study the kinetics and degradation
of global warming gases. However, quantum mechanical methods are also useful for
the kinetic and radiative forcing study of global warming species and can
precede experimental investigations. Research has also been targeted to develop
more adapted procedures using ab initio and density functional theory (DFT)
methods. This report provides a global perspective, in simplified manner, of the
theoretical studies of the degradation of gas species in the atmosphere with an
emphasis on the hydrogen abstraction kinetics of global warming gas species
during their degradation and byproduct formation. En route, the results obtained
from these studies are analysed and compared with experimental data where
available. Our analyses indicate that the theoretical predictions are in
agreement with experimental findings but the predicted parameters are dependent
on the method being used. Theoretical methods are used to predict the
thermodynamic parameters of reactions, and, with relevance to this report, the
global warming potential (GWP) index can also be calculated. This report can be
useful for future investigations involving global warming gaseous species while
providing suggestions on how computations can fill in data gaps when
experimental data are unavailable.
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Kovacevic G, Sabljic A. Mechanisms and reaction-path dynamics of hydroxyl radical reactions with aromatic hydrocarbons: the case of chlorobenzene. CHEMOSPHERE 2013; 92:851-856. [PMID: 23694732 DOI: 10.1016/j.chemosphere.2013.04.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/22/2013] [Accepted: 04/15/2013] [Indexed: 06/02/2023]
Abstract
All geometries and energies significant for the first step of tropospheric degradation of chlorobenzene were characterized using the MP2/6-31+G(d,p) and G3 methods. A pre-reaction complex for the addition of OH radical to chlorobenzene was found and the associated transition state was determined for the first time. The reaction path for the association of OH radical and chlorobenzene into the pre-reaction complex was extrapolated from the selected low frequency normal mode of pre-reaction complex. The reaction rate constant for addition of OH radical to chlorobenzene was determined for the temperature range 230-330K, using RRKM theory and G3 energies. The calculated rate constants are in agreement with the experimental results. Regioselectivity was also determined for the title reaction from the ratio of respective reaction rates and our results are in very good agreement with the experimental results, which show the dominance of the ortho and para channels as well as a negligible contribution by the ipso channel.
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Affiliation(s)
- Goran Kovacevic
- Institute Rudjer Boskovic, POB 180, HR-10002 Zagreb, Croatia
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