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Hickson KM, Loison JC. Kinetic Study of the Gas-Phase O( 1D) + CH 3OH and O( 1D) + CH 3CN Reactions: Low-Temperature Rate Constants and Atomic Hydrogen Product Yields. J Phys Chem A 2022; 126:3903-3913. [PMID: 35687018 DOI: 10.1021/acs.jpca.2c01946] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Atomic oxygen in its first excited singlet state, O(1D), is an important species in the photochemistry of several planetary atmospheres and has been predicted to be a potentially important reactive species on interstellar ices. Here, we report the results of a kinetic study of the reactions of O(1D) with methanol, CH3OH, and acetonitrile, CH3CN, over the 50-296 K temperature range. A continuous supersonic flow reactor is used to attain these low temperatures coupled with pulsed laser photolysis and pulsed laser-induced fluorescence to generate and monitor O(1D) atoms, respectively. Secondary experiments examining the atomic hydrogen product channels of these reactions are also performed, through laser-induced fluorescence measurements of H(2S) atom formation. On the kinetic side, the rate constants for these reactions are seen to be large (>2 × 10-10 cm3 s-1) and consistent with barrierless reactions, although they display contrasting dependences as a function of temperature. On the product formation side, both reactions are seen to yield non-negligible quantities of atomic hydrogen. For the O(1D) + CH3OH reaction, the derived yields are in good agreement with the conclusions of previous experimental and theoretical works. For the O(1D) + CH3CN reaction, whose H-atom formation channels had not previously been investigated, electronic structure calculations of several new product formation channels are performed to explain the observed H-atom yields. These calculations demonstrate the barrierless and exothermic nature of the relevant exit channels, confirming that atomic hydrogen is also an important product of the O(1D) + CH3CN reaction.
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Affiliation(s)
- Kevin M Hickson
- Université Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
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Hickson KM, Loison JC, Larregaray P, Bonnet L, Wakelam V. An Experimental and Theoretical Investigation of the Gas-Phase C( 3P) + N 2O Reaction. Low Temperature Rate Constants and Astrochemical Implications. J Phys Chem A 2022; 126:940-950. [PMID: 35113561 DOI: 10.1021/acs.jpca.1c10112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction between atomic carbon in its ground electronic state, C(3P), and nitrous oxide, N2O, has been studied below room temperature due to its potential importance for astrochemistry, with both species considered to be present at high abundance levels in a range of interstellar environments. On the experimental side, we measured rate constants for this reaction over the 50-296 K range using a continuous supersonic flow reactor. C(3P) atoms were generated by the pulsed photolysis of carbon tetrabromide at 266 nm and were detected by pulsed laser-induced fluorescence at 115.8 nm. Additional measurements allowing the major product channels to be elucidated were also performed. On the theoretical side, statistical rate theory was used to calculate low temperature rate constants. These calculations employed the results of new electronic structure calculations of the 3A″ potential energy surface of CNNO and provided a basis to extrapolate the measured rate constants to lower temperatures and pressures. The rate constant was found to increase monotonically as the temperature falls (kC(3P)+N2O (296 K) = (3.4 ± 0.3) × 10-11 cm3 s-1), reaching a value of kC(3P)+N2O (50 K) = (7.9 ± 0.8) × 10-11 cm3 s-1 at 50 K. As current astrochemical models do not include the C + N2O reaction, we tested the influence of this process on interstellar N2O and other related species using a gas-grain model of dense interstellar clouds. These simulations predict that N2O abundances decrease significantly at intermediate times (103 - 105 years) when gas-phase C(3P) abundances are high.
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Affiliation(s)
- Kevin M Hickson
- Université Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
| | | | - Pascal Larregaray
- Université Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
| | - Laurent Bonnet
- Université Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
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Hickson KM, Bhowmick S, Suleimanov YV, Brandão J, Coelho DV. Experimental and theoretical studies of the gas-phase reactions of O( 1D) with H 2O and D 2O at low temperature. Phys Chem Chem Phys 2021; 23:25797-25806. [PMID: 34761769 DOI: 10.1039/d1cp04614d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we report the results of an experimental and theoretical study of the gas-phase reactions between O(1D) and H2O and O(1D) and D2O at room temperature and below. On the experimental side, the kinetics of these reactions have been investigated over the 50-127 K range using a continuous flow Laval nozzle apparatus, coupled with pulsed laser photolysis and pulsed laser induced fluorescence for the production and detection of O(1D) atoms respectively. Experiments were also performed at 296 K in the absence of a Laval nozzle. On the theoretical side, the existing full-dimensional ground X 1A potential energy surface for the H2O2 system involved in this process has been reinvestigated and enhanced to provide a better description of the barrierless H-atom abstraction pathway. Based on this enhanced potential energy surface, quasiclassical trajectory calculations and ring polymer molecular dynamics simulations have been performed to obtain low temperature rate constants. The measured and calculated rate constants display similar behaviour above 100 K, showing little or no variation as a function of temperature. Below 100 K, the experimental rate constants increase dramatically, in contrast to the essentially temperature independent theoretical values. The possible origins of the divergence between experiment and theory at low temperatures are discussed.
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Affiliation(s)
- Kevin M Hickson
- Université de Bordeaux, Institut des Sciences Moléculaires, F-33400 Talence, France. .,CNRS, Institut des Sciences Moléculaires, F-33400 Talence, France
| | - Somnath Bhowmick
- Computation-based Science and Technology Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.,Climate & Atmosphere Research Centre, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus
| | - Yury V Suleimanov
- Computation-based Science and Technology Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus
| | - João Brandão
- Departamento de Química e Farmácia - FCT, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Daniela V Coelho
- Departamento de Química e Farmácia - FCT, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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Hickson KM, Larrégaray P, Bonnet L, González-Lezana T. The kinetics of X + H2 reactions (X = C(1D), N(2D), O(1D), S(1D)) at low temperature: recent combined experimental and theoretical investigations. INT REV PHYS CHEM 2021. [DOI: 10.1080/0144235x.2021.1976927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Kevin M. Hickson
- Université de Bordeaux, Institut des Sciences Moléculaires, Talence, France
- CNRS, Institut des Sciences Moléculaires, Talence, France
| | - Pascal Larrégaray
- Université de Bordeaux, Institut des Sciences Moléculaires, Talence, France
- CNRS, Institut des Sciences Moléculaires, Talence, France
| | - Laurent Bonnet
- Université de Bordeaux, Institut des Sciences Moléculaires, Talence, France
- CNRS, Institut des Sciences Moléculaires, Talence, France
| | - Tomás González-Lezana
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas IFF-CSIC, Madrid, Spain
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Konings M, Desrousseaux B, Lique F, Loreau J. Benchmarking an improved statistical adiabatic channel model for competing inelastic and reactive processes. J Chem Phys 2021; 155:104302. [PMID: 34525820 DOI: 10.1063/5.0062388] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inelastic collisions and elementary chemical reactions proceeding through the formation and subsequent decay of an intermediate collision complex, with an associated deep well on the potential energy surface, pose a challenge for accurate fully quantum mechanical approaches, such as the close-coupling method. In this study, we report on the theoretical prediction of temperature-dependent state-to-state rate coefficients for these complex-mode processes, using a statistical quantum method. This statistical adiabatic channel model is benchmarked by a direct comparison using accurate rate coefficients from the literature for a number of systems (H2 + H+, HD + H+, SH+ + H, and CH+ + H) of interest in astrochemistry and astrophysics. For all of the systems considered, an error of less than factor 2 was found, at least for the dominant transitions and at low temperatures, which is sufficiently accurate for applications in the above mentioned disciplines.
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Affiliation(s)
- Maarten Konings
- KU Leuven, Division of Quantum Chemistry and Physical Chemistry, Department of Chemistry, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Benjamin Desrousseaux
- Université de Rennes 1, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - François Lique
- Université de Rennes 1, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Jérôme Loreau
- KU Leuven, Division of Quantum Chemistry and Physical Chemistry, Department of Chemistry, Celestijnenlaan 200F, 3001 Leuven, Belgium
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6
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Temperature dependence of the rate coefficient of formation of CN radical from C + NH. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yang Z, Mao Y, Chen M. Quantum Dynamics Studies of the Significant Intramolecular Isotope Effects on the Nonadiabatic Be +( 2P) + HD → BeH +/BeD + + D/H Reaction. J Phys Chem A 2021; 125:235-242. [PMID: 33369408 DOI: 10.1021/acs.jpca.0c09593] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Quantum time-dependent wave packet dynamics studies on the nonadiabatic Be+(2P) + HD → BeH+/BeD+ + D/H reaction are performed for the first time employing recently constructed diabatic potential energy surfaces. Strong intramolecular isotope effects and unusual results are presented, which are attributed to the dynamic effects of shallow wells induced by avoided crossing on the diagonal V22d surface. The BeH+ + D and BeD+ + H channels are dominated by high-J and low-J partial waves, respectively. The BeD+/BeH+ branching ratio is larger than 10 at low energy and gradually decreases with increasing collision energy. The BeH+ product is primarily distributed at low vibrational states, whereas there exists an obvious population inversion of vibrational states on the BeD+ product. The results of differential cross sections suggest that the formation of the BeH+ + D channel favors a direct reaction process, while the BeD+ + H channel is mainly generated by the complex-forming mechanism.
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Affiliation(s)
- Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
| | - Ye Mao
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
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González-Lezana T, Larrégaray P, Bonnet L. Statistical investigations of the S(1D)+HD reaction in the quantum regime. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2020.138228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Espinosa-Garcia J, Garcia-Chamorro M, Corchado JC, Bhowmick S, Suleimanov YV. VTST and RPMD kinetics study of the nine-body X + C 2H 6 (X ≡ H, Cl, F) reactions based on analytical potential energy surfaces. Phys Chem Chem Phys 2020; 22:13790-13801. [PMID: 32538410 DOI: 10.1039/d0cp02238a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermal rate constants of nine-atom hydrogen abstraction reactions, X + C2H6 → HX + C2H5 (X ≡ H, Cl, F) with qualitatively different reaction paths, have been investigated using two kinetics approaches - variational transition state theory with multidimensional tunnelling (VTST/MT) and ring polymer molecular dynamics (RPMD) - and full dimensional analytical potential energy surfaces. For the H + C2H6 reaction, which proceeds through a noticeable barrier height of 11.62 kcal mol-1, kinetics approaches showed excellent agreement between them (with differences less than 30%) and with the experiment (with differences less than 60%) in the wide temperature range of 200-2000 K. For X = Cl and F, however, the situation is very different. The barrier height is either low or very low, 2.44 and 0.23 kcal mol-1, respectively, and the presence of van der Waals complexes in the entrance channel leads to a very flat topography and, consequently, imposes theoretical challenges. For the Cl(2P) reaction, VTST/MT underestimates the experimental rate constants (with differences less than 86%), and RPMD demonstrates better agreement (with differences less than 47%), although the temperature dependence is opposite to the experiment at low temperatures. Finally, for the F(2P) reaction, available experimental information shows discrepancies, both in the absolute values of the rate constants and also in the temperature dependence. Unfortunately, kinetics theories did not resolve this discrepancy. Different possible causes of these theory/experiment discrepancies were analyzed.
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Affiliation(s)
- Joaquin Espinosa-Garcia
- Departamento de Quimica Fisica and Instituto de Computacion Cientifica Avanzada, Universidad de Extremadura, 06071 Badajoz, Spain.
| | - Moises Garcia-Chamorro
- Departamento de Quimica Fisica and Instituto de Computacion Cientifica Avanzada, Universidad de Extremadura, 06071 Badajoz, Spain.
| | - Jose C Corchado
- Departamento de Quimica Fisica and Instituto de Computacion Cientifica Avanzada, Universidad de Extremadura, 06071 Badajoz, Spain.
| | - Somnath Bhowmick
- Computation-based Science and Technology Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
| | - Yury V Suleimanov
- Computation-based Science and Technology Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, Nicosia 2121, Cyprus.
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Nuñez-Reyes D, Bray C, Hickson KM, Larrégaray P, Bonnet L, González-Lezana T. Experimental and theoretical studies of the N(2D) + H2 and D2 reactions. Phys Chem Chem Phys 2020; 22:23609-23617. [DOI: 10.1039/d0cp03971c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study reports the first kinetic measurements of the N(2D) + H2, D2 reactions below 200 K.
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Affiliation(s)
| | - Cédric Bray
- Université de Bordeaux
- Institut des Sciences Moléculaires
- F-33400 Talence
- France
- CNRS
| | - Kevin M. Hickson
- Université de Bordeaux
- Institut des Sciences Moléculaires
- F-33400 Talence
- France
- CNRS
| | - Pascal Larrégaray
- Université de Bordeaux
- Institut des Sciences Moléculaires
- F-33400 Talence
- France
- CNRS
| | - Laurent Bonnet
- Université de Bordeaux
- Institut des Sciences Moléculaires
- F-33400 Talence
- France
- CNRS
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