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Liu Y, Li J. An accurate potential energy surface and ring polymer molecular dynamics study of the Cl + CH4→ HCl + CH3reaction. Phys Chem Chem Phys 2020; 22:344-353. [DOI: 10.1039/c9cp05693a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermal rate coefficients for the Cl + CH4/CD4reactions were studied on a new full-dimensional accurate potential energy surface with the spin–orbit corrections considered in the entrance channel.
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Affiliation(s)
- Yang Liu
- School of Chemistry and Chemical Engineering
- Chongqing University
- Chongqing 401331
- China
| | - Jun Li
- School of Chemistry and Chemical Engineering
- Chongqing University
- Chongqing 401331
- China
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2
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Cascarini FJJ, Hornung B, Quinn MS, Robertson PA, Orr-Ewing AJ. Collision Energy Dependence of the Competing Mechanisms of Reaction of Chlorine Atoms with Propene. J Phys Chem A 2019; 123:2679-2686. [DOI: 10.1021/acs.jpca.9b01370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Balázs Hornung
- School of Chemistry, University of Bristol, Cantock’s
Close, Bristol BS8 1TS, United Kingdom
| | - Mitchell S. Quinn
- School of Chemistry, University of Bristol, Cantock’s
Close, Bristol BS8 1TS, United Kingdom
| | - Patrick A. Robertson
- School of Chemistry, University of Bristol, Cantock’s
Close, Bristol BS8 1TS, United Kingdom
| | - Andrew J. Orr-Ewing
- School of Chemistry, University of Bristol, Cantock’s
Close, Bristol BS8 1TS, United Kingdom
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3
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Abstract
The dynamics of chemical reactions in liquid solutions are now amenable to direct study using ultrafast laser spectroscopy techniques and advances in computer simulation methods. The surrounding solvent affects the chemical reaction dynamics in numerous ways, which include: (i) formation of complexes between reactants and solvent molecules; (ii) modifications to transition state energies and structures relative to the reactants and products; (iii) coupling between the motions of the reacting molecules and the solvent modes, and exchange of energy; (iv) solvent caging of reactants and products; and (v) structural changes to the solvation shells in response to the changing chemical identity of the solutes, on timescales which may be slower than the reactive events. This article reviews progress in the study of bimolecular chemical reaction dynamics in solution, concentrating on reactions which occur on ground electronic states. It illustrates this progress with reference to recent experimental and computational studies, and considers how the various ways in which a solvent affects the chemical reaction dynamics can be unravelled. Implications are considered for research in fields such as mechanistic synthetic chemistry.
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Affiliation(s)
- Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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4
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Pandit S, Hornung B, Dunning GT, Preston TJ, Brazener K, Orr-Ewing AJ. Primary vs. secondary H-atom abstraction in the Cl-atom reaction with n-pentane. Phys Chem Chem Phys 2018; 19:1614-1626. [PMID: 27995254 DOI: 10.1039/c6cp07164c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Velocity map imaging (VMI) measurements and quasi-classical trajectory (QCT) calculations on a newly developed, global potential energy surface (PES) combine to reveal the detailed mechanisms of reaction of Cl atoms with n-pentane. Images of the HCl (v = 0, J = 1, 2 and 3) products of reaction at a mean collision energy of 33.5 kJ mol-1 determine the centre-of-mass frame angular scattering and kinetic energy release distributions. The HCl products form with relative populations of J = 0-5 levels that fit to a rotational temperature of 138 ± 13 K. Product kinetic energy release distributions agree well with those derived from a previous VMI study of the pentyl radical co-product [Estillore et al., J. Chem. Phys. 2010, 132, 164313], but the angular distributions show more pronounced forward scattering. The QCT calculations reproduce many of the experimental observations, and allow comparison of the site-specific dynamics of abstraction of primary and secondary H-atoms. They also quantify the relative reactivity towards Cl atoms of the three different H-atom environments in n-pentane.
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Affiliation(s)
- Shubhrangshu Pandit
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Balázs Hornung
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Greg T Dunning
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Thomas J Preston
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Kristian Brazener
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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5
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Espinosa-Garcia J, Rangel C, Suleimanov YV. Kinetics study of the CN + CH4 hydrogen abstraction reaction based on a new ab initio analytical full-dimensional potential energy surface. Phys Chem Chem Phys 2017; 19:19341-19351. [DOI: 10.1039/c7cp03499g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have developed an analytical full-dimensional potential energy surface, named PES-2017, for the gas-phase hydrogen abstraction reaction between the cyano radical and methane.
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Affiliation(s)
- Joaquin Espinosa-Garcia
- Departamento de Química Física and Instituto de Computación Científica Avanzada
- Universidad de Extremadura
- Badajoz
- Spain
| | - Cipriano Rangel
- Departamento de Química Física and Instituto de Computación Científica Avanzada
- Universidad de Extremadura
- Badajoz
- Spain
| | - Yury V. Suleimanov
- Computation-based Science and Technology Research Center
- Cyprus Institute
- Nicosia 2121
- Cyprus
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6
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Totenhofer AJ, Connor JNL, Nyman G. Angular Scattering Dynamics of the CH4 + Cl → CH3 + HCl Reaction Using Nearside-Farside, Local Angular Momentum, and Resummation Theories. J Phys Chem B 2016; 120:2020-32. [PMID: 26625096 DOI: 10.1021/acs.jpcb.5b10189] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The differential cross section (DCS) for the CH4 + Cl → CH3 + HCl reaction is studied at six total energies where all of the species are in their ground states. The scattering (S) matrix elements have been calculated by the rotating line umbrella method for a dual-level ab initio analytic potential energy surface. We make the first application to this reaction of nearside-farside (NF) and local angular momentum (LAM) techniques, including resummation orders (r) of 0, 1, 2, and 3 for the partial-wave series representation of the full scattering amplitude. We find that resummation usually cleans the NF r = 0 DCSs of unphysical oscillations, especially at small angles. This cleaning effect is typically most pronounced when changing from no resummation (r = 0) to r = 1; further resummations from r = 1 to r = 2 and from r = 2 to r = 3 have smaller effects. The NF DCS analyses show that the reaction is N-dominated at sideward and large angles, whereas at small angles there are oscillations caused by NF interference. The NF LAM analysis provides consistent and complementary information, in particular for the total angular momenta that contribute to the reaction at different scattering angles. The NF analyses also provide justification for simpler N-dominant dynamical theories such as the semiclassical optical model, which provides an explanation for the distorted mirror image effect for the moduli of the S matrix elements and the DCSs, as well as the use of a hard-sphere DCS over limited angular ranges.
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Affiliation(s)
- A J Totenhofer
- School of Chemistry, The University of Manchester , Manchester M13 9PL, United Kingdom
| | - J N L Connor
- School of Chemistry, The University of Manchester , Manchester M13 9PL, United Kingdom
| | - Gunnar Nyman
- Department of Chemistry and Molecular Biology, University of Gothenburg , 41296 Gothenburg, Sweden
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Preston TJ, Hornung B, Pandit S, Harvey JN, Orr-Ewing AJ. Dynamical Effects and Product Distributions in Simulated CN + Methane Reactions. J Phys Chem A 2016; 120:4672-82. [DOI: 10.1021/acs.jpca.5b09487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas J. Preston
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Balázs Hornung
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Shubhrangshu Pandit
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Jeremy N. Harvey
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Heverlee), Belgium
| | - Andrew J. Orr-Ewing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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Hornung B, Preston TJ, Pandit S, Harvey JN, Orr-Ewing AJ. Computational Study of Competition between Direct Abstraction and Addition-Elimination in the Reaction of Cl Atoms with Propene. J Phys Chem A 2015; 119:9452-64. [PMID: 26288318 DOI: 10.1021/acs.jpca.5b07052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quasi-classical trajectory calculations on a newly constructed and full-dimensionality potential energy surface (PES) examine the dynamics of the reaction of Cl atoms with propene. The PES is an empirical valence bond (EVB) fit to high-level ab initio energies and incorporates deep potential energy wells for the 1-chloropropyl and 2-chloropropyl radicals, a direct H atom abstraction route to HCl + allyl radical (CH2CHCH2(•)) products (Δ(r)H(298K)(⊖) = −63.1 kJ mol(-1)), and a pathway connecting these regions. In total, 94 000 successful reactive trajectories were used to compute distributions of angular scattering and HCl vibrational and rotational level populations. These measures of the reaction dynamics agree satisfactorily with available experimental data. The dominant reaction pathway is direct abstraction of a hydrogen atom from the methyl group of propene occurring in under 500 fs. Less than 10% of trajectories follow an addition–elimination route via the two isomeric chloropropyl radicals. Large amplitude motions of the Cl about the propene molecular framework couple the addition intermediates to the direct abstraction pathway. The EVB method provides a good description of the complicated PES for the Cl + propene reaction despite fitting to a limited number of ab initio points, with the further advantage that dynamics specific to certain mechanisms can be studied in isolation by switching off coupling terms in the EVB matrix connecting different regions of the PES.
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Affiliation(s)
- Balázs Hornung
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Thomas J Preston
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Shubhrangshu Pandit
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Jeremy N Harvey
- Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001 Leuven (Heverlee), Belgium
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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