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Zhang S, Chen Q, Zhang L, Li J, Hu X, Xie D. Dynamics studies for the multi-well and multi-channel reaction of OH with C 2H 2 on a full-dimensional global potential energy surface. Phys Chem Chem Phys 2024; 26:7351-7362. [PMID: 38375620 DOI: 10.1039/d3cp05811e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The C2H2 + OH reaction is an important acetylene oxidation pathway in the combustion process, as well as a typical multi-well and multi-channel reaction. Here, we report an accurate full-dimensional machine learning-based potential energy surface (PES) for the C2H2 + OH reaction at the UCCSD(T)-F12b/cc-pVTZ-F12 level, based on about 475 000 ab initio points. Extensive quasi-classical trajectory (QCT) calculations were performed on the newly developed PES to obtain detailed dynamic data and analyze reaction mechanisms. Below 1000 K, the C2H2 + OH reaction produces H + OCCH2 and CO + CH3. With increasing temperature, the product channels H2O + C2H and H + HCCOH are accessible and the former dominates above 1900 K. It is found that the formation of H2O + C2H is dominated by a direct reaction process, while other channels belong to the indirect mechanism involving long-lived intermediates along the reaction pathways. At low temperatures, the C2H2 + OH reaction behaves like an unimolecular reaction due to the unique PES topographic features, of which the dynamic features are similar to the decomposition of energy-rich complexes formed by C2H2 + OH collision. The classification of trajectories that undergo different reaction pathways to generate each product and their product energy distributions were also reported in this work. This dynamic information may provide a deep understanding of the C2H2 + OH reaction.
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Affiliation(s)
- Shuwen Zhang
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Qixin Chen
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Lidong Zhang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China; State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China.
| | - Jun Li
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
| | - Xixi Hu
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China.
- Hefei National Laboratory, Hefei 230088, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Hefei National Laboratory, Hefei 230088, China
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2
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Perrero J, Enrique-Romero J, Martínez-Bachs B, Ceccarelli C, Balucani N, Ugliengo P, Rimola A. Non-energetic Formation of Ethanol via CCH Reaction with Interstellar H 2O Ices. A Computational Chemistry Study. ACS EARTH & SPACE CHEMISTRY 2022; 6:496-511. [PMID: 35330630 PMCID: PMC8935465 DOI: 10.1021/acsearthspacechem.1c00369] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/21/2022] [Accepted: 02/27/2022] [Indexed: 05/30/2023]
Abstract
Ethanol (CH3CH2OH) is a relatively common molecule, often found in star-forming regions. Recent studies suggest that it could be a parent molecule of several so-called interstellar complex organic molecules (iCOMs). However, the formation route of this species remains under debate. In the present work, we study the formation of ethanol through the reaction of CCH with one H2O molecule belonging to the ice as a test case to investigate the viability of chemical reactions based on a "radical + ice component" scheme as an alternative mechanism for the synthesis of iCOMs, beyond the usual radical-radical coupling. This has been done by means of DFT calculations adopting two clusters of 18 and 33 water molecules as ice models. Results indicate that CH3CH2OH can potentially be formed by this proposed reaction mechanism. The reaction of CCH with H2O on the water ice clusters can be barrierless (because of the help of boundary icy water molecules acting as proton-transfer assistants), leading to the formation of vinyl alcohol precursors (H2CCOH and CHCHOH). Subsequent hydrogenation of vinyl alcohol yielding ethanol is the only step presenting a low activation energy barrier. We finally discuss the astrophysical implications of these findings.
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Affiliation(s)
- Jessica Perrero
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, 08193 Catalonia, Spain
- Dipartimento
di Chimica and Nanostructured Interfaces and Surfaces (NIS) Centre, Università degli Studi di Torino, via P. Giuria 7, 10125 Torino, Italy
| | - Joan Enrique-Romero
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, 08193 Catalonia, Spain
- Univ.
Grenoble Alpes, CNRS, Institut de Planétologie
et d’Astrophysique de Grenoble (IPAG), 38000 Grenoble, France
| | - Berta Martínez-Bachs
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, 08193 Catalonia, Spain
| | - Cecilia Ceccarelli
- Univ.
Grenoble Alpes, CNRS, Institut de Planétologie
et d’Astrophysique de Grenoble (IPAG), 38000 Grenoble, France
| | - Nadia Balucani
- Univ.
Grenoble Alpes, CNRS, Institut de Planétologie
et d’Astrophysique de Grenoble (IPAG), 38000 Grenoble, France
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
- Osservatorio
Astrosico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
| | - Piero Ugliengo
- Dipartimento
di Chimica and Nanostructured Interfaces and Surfaces (NIS) Centre, Università degli Studi di Torino, via P. Giuria 7, 10125 Torino, Italy
| | - Albert Rimola
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, 08193 Catalonia, Spain
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3
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Bowman MC, Burke AD, Turney JM, Schaefer III HF. Conclusive determination of ethynyl radical hydrogen abstraction energetics and kinetics*. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1769214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Michael C. Bowman
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA, USA
- Department of Chemistry and Biochemistry, Taylor University, Upland, IN, USA
| | - Alexandra D. Burke
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA, USA
| | - Justin M. Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA, USA
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4
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Adamson SO. Reactions C2H2 + OH and C2 + H2O: Ab initio study of the potential energy surfaces. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2016. [DOI: 10.1134/s1990793116010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Jung SH, Jang SC, Kim JW, Kim JW, Choi JH. Theoretical Investigation of the Radical-Radical Reaction of O((3)P) + C2H3 and Comparison with Gas-Phase Crossed-Beam Experiments. J Phys Chem A 2015; 119:11761-71. [PMID: 26562486 DOI: 10.1021/acs.jpca.5b09191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, we present an ab initio study of the prototypal radical-radical reactions of ground-state atomic oxygen [O((3)P)] with the vinyl (C2H3) radical using density functional theory and a complete basis set model. Two distinctive pathways on the lowest doublet potential energy surfaces (PESs) were predicted to be in competition: addition and abstraction. The barrierless addition of O((3)P) to the hydrocarbon radicals leads to energy-rich intermediate formation followed by subsequent isomerization and decomposition to yield various products: CH2CO (ketene) + H, CO + CH3, C2HOH (acetylenol) + H, (3,1)CCHOH + H, H2O + C2H, (3,1)CH2 + HCO, H2CO (formaldehyde) + CH, C2H2 (acetylene) + OH, and (3,1)CCH2 + OH. The competing but minor H-atom abstraction mechanisms produce C2H2 + OH and (1,3)CCH2 + OH. The optimized structures of the reactants, products, intermediates, and transition states and the reaction mechanisms were obtained on the lowest doublet PESs. The major pathway was predicted to be the formation of CH2CO + H through the low-barrier, single-step cleavages of the addition intermediates. The Levine-Bernstein prior method, statistical surprisal approach, and microcanonical Rice-Ramsperger-Kassel-Marcus theory were applied to deduce the energy distributions of H atoms and OH products and quantitative rate constants. On the basis of the statistical theory and the population analysis, the predicted energy distributions were compared to the kinetic energy release of H and the preferential population of the Π(A') component of OH products reported in recent gas-phase crossed-beam investigations (Park, M. J.; Jang, S. C.; Choi, J. H. J. Chem. Phys. 2012, 137, 204311), and their kinetic and dynamic characteristics were discussed.
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Affiliation(s)
- Se-Hee Jung
- Department of Chemistry, Research Institute for Natural Sciences, Korea University , Anam-dong, Seoul 136-701, Republic of Korea
| | - Su-Chan Jang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University , Anam-dong, Seoul 136-701, Republic of Korea
| | - Jin-Wook Kim
- Department of Chemistry, Research Institute for Natural Sciences, Korea University , Anam-dong, Seoul 136-701, Republic of Korea
| | - Jang-Woon Kim
- Department of Chemistry, Research Institute for Natural Sciences, Korea University , Anam-dong, Seoul 136-701, Republic of Korea
| | - Jong-Ho Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University , Anam-dong, Seoul 136-701, Republic of Korea
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6
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Zeng T, Danovich D, Shaik S, Ananth N, Hoffmann R. Tuning the Ground State Symmetry of Acetylenyl Radicals. ACS CENTRAL SCIENCE 2015; 1:270-278. [PMID: 27162981 PMCID: PMC4827494 DOI: 10.1021/acscentsci.5b00187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Indexed: 06/05/2023]
Abstract
The lowest excited state of the acetylenyl radical, HCC, is a (2)Π state, only 0.46 eV above the ground state, (2)Σ(+). The promotion of an electron from a π bond pair to a singly occupied σ hybrid orbital is all that is involved, and so we set out to tune those orbital energies, and with them the relative energetics of (2)Π and (2)Σ(+) states. A strategy of varying ligand electronegativity, employed in a previous study on substituted carbynes, RC, was useful, but proved more difficult to apply for substituted acetylenyl radicals, RCC. However, π-donor/acceptor substitution is effective in modifying the state energies. We are able to design molecules with (2)Π ground states (NaOCC, H2NCC ((2)A″), HCSi, FCSi, etc.) and vary the (2)Σ(+)-(2)Π energy gap over a 4 eV range. We find an inconsistency between bond order and bond dissociation energy measures of the bond strength in the Si-containing molecules; we provide an explanation through an analysis of the relevant potential energy curves.
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Affiliation(s)
- Tao Zeng
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
| | - David Danovich
- Institute
of Chemistry and The Lise Meitner-Minerva Center for Computational
Quantum Chemistry, Hebrew University of
Jerusalem, 91904 Jerusalem, Israel
| | - Sason Shaik
- Institute
of Chemistry and The Lise Meitner-Minerva Center for Computational
Quantum Chemistry, Hebrew University of
Jerusalem, 91904 Jerusalem, Israel
| | - Nandini Ananth
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
| | - Roald Hoffmann
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
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7
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Douberly GE, Raston PL, Liang T, Marshall MD. Infrared rovibrational spectroscopy of OH–C2H2 in 4He nanodroplets: Parity splitting due to partially quenched electronic angular momentum. J Chem Phys 2015; 142:134306. [DOI: 10.1063/1.4916394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | - Paul L. Raston
- Department of Chemistry, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Tao Liang
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | - Mark D. Marshall
- Department of Chemistry, Amherst College, Amherst, Massachusetts 01002-5000, USA
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8
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Jang SC, Choi JH. Probing the kinetic energy-release dynamics of H-atom products from the gas-phase reaction of O(3P) with vinyl radical C2H3. Phys Chem Chem Phys 2014; 16:23679-85. [PMID: 25272025 DOI: 10.1039/c4cp03046j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The gas-phase radical-radical reaction dynamics of ground-state atomic oxygen O((3)P) with vinyl radicals C2H3 has been studied by combining the results of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration with ab initio calculations. The two radical reactants O((3)P) and C2H3 were produced by photolysis of NO2 and supersonic flash pyrolysis of C2H3I, respectively. Doppler profile analysis of the kinetic energy release of the nascent H-atom products from the title reaction O((3)P) + C2H3→ H((2)S) + CH2CO (ketene) revealed that the average translational energy of the products and the average fraction of the total available energy were 7.03 ± 0.30 kcal mol(-1) and 7.2%. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title oxygen-hydrogen exchange reaction is a major reaction channel, through an addition-elimination mechanism involving the formation of a short-lived, dynamical complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed kinetic energy release can be explained in terms of the weak impulse at the moment of decomposition in the loose transition state with a product-like geometry and a small reverse barrier along the exit channel.
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Affiliation(s)
- Su-Chan Jang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 1, Anam-dong, Seoul 136-701, Korea.
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9
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Park MJ, Jang SC, Choi JH. A combined crossed-beam and theoretical study of the reaction dynamics of O(3P) + C2H3 → C2H2 + OH: analysis of the nascent OH products with the preferential population of the Π(A') component. J Chem Phys 2012. [PMID: 23206007 DOI: 10.1063/1.4767772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The gas-phase reaction dynamics of ground-state atomic oxygen [O((3)P) from the photo-dissociation of NO(2)] with vinyl radicals [C(2)H(3) from the supersonic flash pyrolysis of vinyl iodide, C(2)H(3)I] has been investigated using a combination of high-resolution laser-induced fluorescence spectroscopy in a crossed-beam configuration and ab initio calculations. Unlike the previous gas-phase bulk kinetic experiments by Baulch et al. [J. Phys. Chem. Ref. Data 34, 757 (2005)], a new exothermic channel of O((3)P) + C(2)H(3) → C(2)H(2) + OH (X (2)Π: υ" = 0) has been identified for the first time, and the population analysis shows bimodal nascent rotational distributions of OH products with low- and high-N" components with a ratio of 2.4:1. No spin-orbit propensities were observed, and the averaged ratios of Π(A('))∕Π(A") were determined to be 1.66 ± 0.27. On the basis of computations at the CBS-QB3 theory level and comparison with prior theory, the microscopic mechanisms responsible for the nascent populations can be understood in terms of two competing dynamical pathways: a direct abstraction process in the low-N" regime as the major pathway and an addition-complex forming process in the high-N" regime as the minor pathway. Particularly, during the bond cleavage process of the weakly bound van der Waals complex C(2)H(2)-OH, the characteristic pathway from the low dihedral-angle geometry was consistent with the observed preferential population of the Π(A') component in the nascent OH products. A molecular-level discussion of the reactivity, mechanism, and dynamical features of the title reaction are presented together with a comparison to gas-phase oxidation reactions of a series of prototypical hydrocarbon radicals.
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Affiliation(s)
- Min-Jin Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 1, Anam-dong, Seoul 136-701, Korea
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10
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Kryachko ES, Scheiner S. Bonding rearrangements of hydrogen-bonded complexes involving alkynes. J Phys Chem A 2008; 112:1940-5. [PMID: 18266343 DOI: 10.1021/jp076795e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecules containing a C-C triple bond, such as HC[triple bond]CH, FC[triple bond]CF, and the C[triple bond]CH radical, are allowed to interact with a partner molecule of H2O, NH3, or HF. Quantum chemical calculations show that these C[triple bond]CH...X H-bonded complexes are bound by up to 4 kcal x mol(-1). More importantly, they can rearrange in such a way that the partner molecule adds to the triple bond so as to form a double C=C bond. Whereas this process is strongly exoergic, there is a high-energy barrier to this rearrangement process. On the other hand, when a second water molecule is added to the complex, it can shuttle protons from the donor part of the complex to the acceptor, and thereby greatly reduce the rearrangement energy barrier. In the case of CCH + 2H2O, this barrier is computed to be less than 4 kcal x mol(-1).
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Affiliation(s)
- Eugene S Kryachko
- Department of Chemistry, Bat. B6c, University of Liege, Sart-Tilman, B-4000 Liege 1, Belgium.
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11
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Bennett DIG, Butler LJ, Werner HJ. Comparing electronic structure predictions for the ground state dissociation of vinoxy radicals. J Chem Phys 2007; 127:094309. [PMID: 17824741 DOI: 10.1063/1.2753489] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper reports a series of electronic structure calculations performed on the dissociation pathways of the vinoxy radical (CH(2)CHO). We use coupled-cluster with single, double, and perturbative triple excitations (CCSD(T)), complete active space self-consistent field (CASSCF), multireference configuration interaction (MRCI), and MRCI with the Davidson correction (MRCI+Q) to calculate the barrier heights of the two unimolecular dissociation pathways of this radical. The effect of state averaging on the barrier heights is investigated at the CASSCF, MRCI, and MRCI+Q levels. The change in mixing angle along the reaction path is calculated as a measure of derivative coupling and found to be insufficient to suggest nonadiabatic recrossing. We also present a new analysis of previous experimental data on the unimolecular dissociation of ground state vinoxy. In particular, an error in the internal energy distribution of vinoxy radicals reported in a previous paper is corrected and a new analysis of the experimental sensitivity to the onset energy (barrier height) for the isomerization reaction is given. Combining these studies, a final "worst case" analysis of the product branching ratio is given and a statistical model using each of the calculated transition states is found to be unable to correctly reproduce the experimental data.
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Affiliation(s)
- Doran I G Bennett
- The James Franck Institute and The Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
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12
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Carl SA, Vereecken L, Peeters J. Kinetic parameters for gas-phase reactions: experimental and theoretical challenges. Phys Chem Chem Phys 2007; 9:4071-84. [PMID: 17687459 DOI: 10.1039/b705505f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article aims to illustrate the added value provided to experimental kinetics investigations by complementary theoretical kinetics studies, using as examples (i) reactions of two major hydrocarbon flame radicals, HCCO and C(2)H, and (ii) reactions of several oxygenated organic compounds with hydroxyl radicals of interest to atmospheric chemistry. The first part, on HCCO and C(2)H kinetics, does not attempt to give an extensive literature review, but rather addresses some major experimental techniques, mainly specific ones, that have allowed a great part of the available reactivity databases on these two species to be established. For several key reactions, it is shown how potential energy surfaces and statistical rate predictions based thereon have provided insight into the molecular mechanisms and have allowed estimates of product distributions as well as reliable extrapolations of experimental rate coefficients and branching ratios to higher temperatures. The second part addresses current issues in atmospheric chemistry relating mainly to hydroxyl radical reactions with oxygenated organics, and focuses on the experimental characterization of the often unusual temperature dependence of their rate coefficients and on the theoretical rationalization thereof, through the formation of hydrogen-bonded pre-reactive complexes and resulting tunnelling-enhanced H-abstraction. Finally, the development of general structure-activity relationships for OH reactions with organics, H-abstractions as well as OH-additions for unsaturated compounds, is briefly discussed.
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Affiliation(s)
- S A Carl
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
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13
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Abstract
The title unknown reaction is theoretically studied at various levels to probe the interaction mechanism between the ethynyl radical (HC triple bond C) and formaldehyde (H(2)C double bond O). The most feasible pathway is a barrier-free direct H-abstraction process leading to acetylene and formyl radical (C(2)H(2)+HCO) via a weakly bound complex, and then the product can take secondary dissociation to the final product C(2)H(2)+CO+H. The C-addition channel leading to propynal plus H-atom (HCCCHO+H) has the barrier of only 3.6, 2.9, and 2.1 kcal/mol at the CCSD(T)/6-311+G(3df,2p)MP2//6-311G(d,p)+ZPVE, CCSD(T)/6-311+G(3df,2p)//QCISD/6-311G(d,p)+ZPVE, and G3//MP2 levels, respectively [CCSD(T)--coupled cluster with single, double, and triple excitations; ZPVE--zero-point vibrational energy; QCISD--quadratic configuration interaction with single and double excitations; G3//MP2-Gaussian-3 based on Moller-Plesset geometry]. The O addition also leading to propynal plus H atom needs to overcome a higher barrier of 5.3, 8.7, and 3.0 kcalmol at the three corresponding levels. The title no-barrier reaction presents a new efficient route to remove the pollutant H(2)CO, and should be included in the combustion models of hydrocarbons. It may also represent the fastest radical-H(2)CO reaction among the available theoretical data. Moreover, it could play an important role in the interstellar chemistry where the zero- or minute-barrier reactions are generally favored. Discussions are also made on the possible formation of the intriguing propynal in space via the title reaction on ice surface.
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Affiliation(s)
- Hao Dong
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
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14
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Cheng Z, Li Y. What is responsible for the initiating chemistry of iron-mediated lipid peroxidation: an update. Chem Rev 2007; 107:748-66. [PMID: 17326688 DOI: 10.1021/cr040077w] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Zhiyong Cheng
- The Key Laboratory of Bioorganic & Molecular Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing, China 100871
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15
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Carl SA, Nguyen HMT, Elsamra RMI, Nguyen MT, Peeters J. Pulsed laser photolysis and quantum chemical-statistical rate study of the reaction of the ethynyl radical with water vapor. J Chem Phys 2005; 122:114307. [PMID: 15836215 DOI: 10.1063/1.1861887] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The rate coefficient of the gas-phase reaction C(2)H + H(2)O-->products has been experimentally determined over the temperature range 500-825 K using a pulsed laser photolysis-chemiluminescence (PLP-CL) technique. Ethynyl radicals (C(2)H) were generated by pulsed 193 nm photolysis of C(2)H(2) in the presence of H(2)O vapor and buffer gas N(2) at 15 Torr. The relative concentration of C(2)H radicals was monitored as a function of time using a CH* chemiluminescence method. The rate constant determinations for C(2)H + H(2)O were k(1)(550 K) = (2.3 +/- 1.3) x 10(-13) cm(3) s(-1), k(1)(770 K) =(7.2 +/- 1.4) x 10(-13) cm(3) s(-1), and k(1)(825 K) = (7.7 +/- 1.5) x 10(-13) cm(3) s(-1). The error in the only other measurement of this rate constant is also discussed. We have also characterized the reaction theoretically using quantum chemical computations. The relevant portion of the potential energy surface of C(2)H(3)O in its doublet electronic ground state has been investigated using density functional theory B3LYP6-311 + + G(3df,2p) and molecular orbital computations at the unrestricted coupled-cluster level of theory that incorporates all single and double excitations plus perturbative corrections for the triple excitations, along with the 6-311 + + G(3df,2p) basis set [(U)CCSD(T)6-311 + + G(3df,2p)] and using UCCSD(T)6-31G(d,p) optimized geometries. Five isomers, six dissociation products, and sixteen transition structures were characterized. The results confirm that the hydrogen abstraction producing C(2)H(2)+OH is the most facile reaction channel. For this channel, refined computations using (U)CCSD(T)6-311 + + G(3df,2p)(U)CCSD(T)6-311 + + G(d,p) and complete-active-space second-order perturbation theory/complete-active-space self-consistent-field theory (CASPT2/CASSCF) [B. O. Roos, Adv. Chem. Phys. 69, 399 (1987)] using the contracted atomic natural orbitals basis set (ANO-L) [J. Almlof and P. R. Taylor, J. Chem. Phys.86, 4070 (1987)] were performed, yielding zero-point energy-corrected potential energy barriers of 17 kJ mol(-1) and 15 kJ mol(-1), respectively. Transition-state theory rate constant calculations, based on the UCCSD(T) and CASPT2/CASSCF computations that also include H-atom tunneling and a hindered internal rotation, are in perfect agreement with the experimental values. Considering both our experimental and theoretical determinations, the rate constant can best be expressed, in modified Arrhenius form as k(1)(T) = (2.2 +/- 0.1) x 10(-21)T(3.05) exp[-(376 +/- 100)T] cm(3) s(-1) for the range 300-2000 K. Thus, at temperatures above 1500 K, reaction of C(2)H with H(2)O is predicted to be one of the dominant C(2)H reactions in hydrocarbon combustion.
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Affiliation(s)
- Shaun A Carl
- Department of Chemistry, University of Leuven, Belgium.
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Dong H, Ding YH, Sun CC. Radical-molecule reaction C3H+H2O: A mechanistic study. J Chem Phys 2005; 122:064303. [PMID: 15740368 DOI: 10.1063/1.1844301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Despite the importance of the C(3)H radical in both combustion and interstellar space, the reactions of C(3)H toward stable molecules have never been studied. In this paper, we report our detailed mechanistic study on the radical-molecule reaction C(3)H+H(2)O at the Becke's three parameter Lee-Yang-Parr-B3LYP6-311G(d,p) and coupled cluster with single, double, and triple excitations-CCSD(T)6-311G(2d,p) (single-point) levels. It is shown that the C(3)H+H(2)O reaction initially favors formation of the carbene-insertion intermediates HCCCHOH (1a,1b) rather than the direct H- or OH-abstraction process. Subsequently, the isomers (1a,1b) can undergo a direct H- extrusion to form the well-known product propynal HCCCHO (P(5)). Highly competitively, (1a,1b) can take the successive 1,4- and 1,2-H-shift interconversion to isomer H(2)CCCHO(2a,2b) and then to isomer H(2)CCHCO(3a,3b), which can finally take a direct C-C bond cleavage to give product C(2)H(3) and CO (P(1)). The other products are kinetically much less feasible. With the overall entrance barrier 10.6 kcal/mol, the title reaction can be important in postburning processes. Particularly, our calculations suggest that the title reaction may play a role in the formation of the intriguing interstellar molecule, propynal HCCCHO. The calculated results will also be useful for the analogous C(3)H reactions such as with ammonia and alkanes.
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Affiliation(s)
- Hao Dong
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
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Wang J, Ding YH, Wu GB, Sun CC. Gaseous reaction mechanism of C2F radical with water. J Comput Chem 2005; 27:363-7. [PMID: 16365868 DOI: 10.1002/jcc.20352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The kinetic properties of the carbon-fluorine radicals are little understood except those of CFn (n =1-3). In this article, a detailed mechanistic study was reported on the gas-phase reaction between the simplest pi-bonded C2F radical and water as the first attempt to understand the chemical reactivity of the C2F radical. Various reaction channels are considered. The most kinetically competitive channel is the quasi-direct hydrogen-abstraction route forming P5 HCCF + OH. At the CCSD(T)/6-311+G(2d,2p)//B3LYP/6-311G(d,p)+ZPVE, CCSD(T)/6-311+G(3df,2p)//QCISD/6-311G(d,p)+ZPVE and Gaussian-3//B3LYP/6-31G(d) levels, the overall H-abstraction barriers (4.5, 4.7, and 4.2 kcal/mol) for the C2F + H2O reaction are comparable to the corresponding values (5.5, 3.7, and 5.7 kcal/mol) for the analogous C2H + H2O reaction. This suggests that C2F is a reactive radical like the extensively studied C2H, in contrast to the situation of the CF and CF2 radicals that have much lower reactivity than the corresponding hydrocarbon species. Thus, the C2F radical is expected to play an important role in the combustion processes of the carbon-fluorine chemistry. Furthermore, addition of a second H2O can catalyze the reaction with the H-abstraction barrier significantly reduced to a marginally zero value (0.5 kcal/mol). This is also indicative of the potential relevance of the title reactions in the low-temperature atmospheric chemistry.
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Affiliation(s)
- Jian Wang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
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Golovin A, Takhistov V. Thermochemistry of organic and heteroorganic species. Part XII. Mono- and disubstituted acetylenes and ethynyl free radicals. New electronegativity scale. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2004.01.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Davey JB, Greenslade ME, Marshall MD, Lester MI, Wheeler MD. Infrared spectrum and stability of a π-type hydrogen-bonded complex between the OH and C2H2 reactants. J Chem Phys 2004; 121:3009-18. [PMID: 15291610 DOI: 10.1063/1.1768933] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A hydrogen-bonded complex between the hydroxyl radical and acetylene has been stabilized in the reactant channel well leading to the addition reaction and characterized by infrared action spectroscopy in the OH overtone region. Analysis of the rotational band structure associated with the a-type transition observed at 6885.53(1) cm(-1) (origin) reveals a T-shaped structure with a 3.327(5) A separation between the centers of mass of the monomer constituents. The OH (v = 1) product states populated following vibrational predissociation show that dissociation proceeds by two mechanisms: intramolecular vibrational to rotational energy transfer and intermolecular vibrational energy transfer. The highest observed OH product state establishes an upper limit of 956 cm(-1) for the stability of the pi-type hydrogen-bonded complex. The experimental results are in good accord with the intermolecular distance and well depth at the T-shaped minimum energy configuration obtained from complementary ab initio calculations, which were carried out at the restricted coupled cluster singles, doubles, noniterative triples level of theory with extrapolation to the complete basis set limit.
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Affiliation(s)
- James B Davey
- Department of Chemistry, University of Pennsylvania, Philadelphia 19104-6323, USA
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Affiliation(s)
- Allan H Laufer
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
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Li QS, Xu XD, Zhang S. Predicting energies and geometries for reactions involved in atmosphere chemistry: a comparison study between hybrid DFT methods. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2003.11.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cao DB, Ding YH, Li ZS, Huang XR, Sun CC. Theoretical Study on Potential Energy Surface of the C2H2FO Radical. J Phys Chem A 2002. [DOI: 10.1021/jp014353b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Dong-bo Cao
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Yi-hong Ding
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Ze-sheng Li
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Xu-ri Huang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Chia-chung Sun
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
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