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Agarwal A, Boruah PJ, Ahamed SS, Baruah S, Paul AK. Post-Transition State Direct Dynamics Simulations on the Ozonolysis of Catechol in an N 2 Bath and Comparison with Gas-Phase Results. J Phys Chem A 2023; 127:6804-6815. [PMID: 37531625 DOI: 10.1021/acs.jpca.3c03326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Chemical dynamics simulations on the post-transition state dynamics of ozonolysis of catechol are performed in this article using a newly developed QM + MM simulation model. The reaction is performed in a bath of N2 molecules equilibrated at 300 K. Two bath densities, namely, 20 and 324 kg/m3, are considered for the simulation. The excitation temperatures of a catechol-O3 moiety are taken as 800, 1000, and 1500 K for each density. At these new excitation temperatures, the gas-phase results are also computed to compare the results and quantify the effect of surrounding molecules on this reaction. Like the previous findings, five reaction channels are observed in the present investigation, producing CO2, CO, O2, small carboxylic acid (SCA), and H2O. The probabilities of these products are discussed with the role of bath densities. Results from the gas-phase simulation and density of 20 kg/m3 are very similar, whereas results differ significantly at a higher bath density of 324 kg/m3. The rate constants for the unimolecular channel at each temperature and density are also calculated and reported. The QM + MM setup used here can also be used for other chemical reactions, where the solvent effect is important.
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Affiliation(s)
- Ankita Agarwal
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Palash Jyoti Boruah
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Sk Samir Ahamed
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Shrutimala Baruah
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Amit Kumar Paul
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
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2
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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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3
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Jasper A. Predicting third-body collision efficiencies for water and other polyatomic baths. Faraday Discuss 2022; 238:68-86. [DOI: 10.1039/d2fd00038e] [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
Low-pressure-limit microcanonical (collisional activation) and thermal rate constants are predicted using a combination of automated ab initio potential energy surface construction, classical trajectories, transition state theory, and a detailed kinetic...
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4
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Kuwata KT, DeVault MP, Claypool DJ. Improved Computational Modeling of the Kinetics of the Acetylperoxy + HO 2 Reaction. Faraday Discuss 2022; 238:589-618. [DOI: 10.1039/d2fd00030j] [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
The acetylperoxy + HO2 reaction has multiple impacts on the troposphere, with a triplet pathway leading to peracetic acid + O2 (reaction 1a) competing with singlet pathways leading to acetic...
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5
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Lu D, Chen J, Guo H, Li J. Vibrational energy pooling via collisions between asymmetric stretching excited CO 2: a quasi-classical trajectory study on an accurate full-dimensional potential energy surface. Phys Chem Chem Phys 2021; 23:24165-24174. [PMID: 34671798 DOI: 10.1039/d1cp03687d] [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
In low temperature plasmas, energy transfer between asymmetric stretching excited CO2 molecules can be highly efficient, which leads to further excitation (and de-excitation) of the CO2 molecules: CO2(vas) + CO2(vas) → CO2(vas + 1) + CO2(vas - 1). Through such a vibrational ladder climbing mechanism, CO2 can be activated and eventually dissociates. To gain mechanistic insight of such processes, a full-dimensional accurate potential energy surface (PES) for the CO2 + CO2 system is developed using the permutational invariant polynomial-neural network method based on CCSD(T)-F12a/AVTZ energies at about 39 000 geometries. This PES is used in quasi-classical trajectory (QCT) studies of the vibrational energy transfer between CO2 molecules excited in the asymmetric stretching mode. A machine learning algorithm is used to determine state-specific rate coefficients for the vibrational transfer processes from a limited data set. In addition to the CO2(vas + 1) + CO2(vas - 1) channel, the QCT simulations revealed significant contributions from the CO2(vas + 2,3) + CO2(vas - 2,3) channels, particularly at low collision energies/temperatures. These multi-vibrational-quantum processes are attributed to enhanced energy flow in the collisional complex formed by enhanced dipole-dipole interaction between asymmetric stretching excited CO2 molecules.
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Affiliation(s)
- Dandan Lu
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China. .,Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Jun Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Jun Li
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
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6
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Hren ZR, Lazarock CR, Vincent TA, Rivera-Rivera LA, Wagner AF. Pressure Effects on the Relaxation of an Excited Ethane Molecule in High-Pressure Bath Gases. J Phys Chem A 2021; 125:8680-8690. [PMID: 34582214 DOI: 10.1021/acs.jpca.1c05838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use molecular dynamics to calculate the rotational and vibrational energy relaxation of C2H6 in Ar, Kr, and Xe bath gases over a pressure range of 10-400 atm and at temperatures of 300 and 800 K. The C2H6 is instantaneously excited by 80 kcal/mol randomly distributed into both vibrational and rotational modes. The computed relaxation rates show little sensitivity to the identity of the noble gas in the bath. Vibrational relaxation rates show a nonlinear pressure dependence at 300 K. At 800 K the reduced range of bath gas densities covered by the range of pressures does not yet show any nonlinearity in the pressure dependence. Rotational relaxation is characterized with two relaxation rates. The slower rate is comparable to the vibrational relaxation rate. The faster rate has a linear pressure dependence at 300 K but an irregular, nonlinear pressure dependence at 800 K. To understand this, a model was developed based on approximating the periodic box used in the molecular dynamics simulations by an equal-volume collection of cubes where each cube is sized to allow only single occupancy by the noble gas or the molecule. Combinatorial statistics then leads to a pressure- and temperature-dependent analytic distribution of the bath gas species the molecule encounters in a collision. This distribution, the dissociation energy of molecule/bath gas complexes and bath gas clusters, and the computed energy release per collision combine to show that only at 300 K is the energy release sufficient to dissociate likely complexes and clusters. This suggests that persistent and pressure-dependent clusters and complexes at 800 K may be responsible for the nonlinear pressure dependence of rotational relaxation.
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Affiliation(s)
- Zackary R Hren
- Department of Physical Sciences, Ferris State University, Big Rapids, Michigan 49307, United States
| | - Chad R Lazarock
- Department of Physical Sciences, Ferris State University, Big Rapids, Michigan 49307, United States
| | - Tasha A Vincent
- Department of Physical Sciences, Ferris State University, Big Rapids, Michigan 49307, United States
| | - Luis A Rivera-Rivera
- Department of Physical Sciences, Ferris State University, Big Rapids, Michigan 49307, United States
| | - Albert F Wagner
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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7
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Ahamed SS, Kim H, Paul AK, West NA, Winner JD, Donzis DA, North SW, Hase WL. Comparison of intermolecular energy transfer from vibrationally excited benzene in mixed nitrogen-benzene baths at 140 K and 300 K. J Chem Phys 2020; 153:144116. [PMID: 33086796 DOI: 10.1063/5.0021293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Gas phase intermolecular energy transfer (IET) is a fundamental component of accurately explaining the behavior of gas phase systems in which the internal energy of particular modes of molecules is greatly out of equilibrium. In this work, chemical dynamics simulations of mixed benzene/N2 baths with one highly vibrationally excited benzene molecule (Bz*) are compared to experimental results at 140 K. Two mixed bath models are considered. In one, the bath consists of 190 N2 and 10 Bz, whereas in the other bath, 396 N2 and 4 Bz are utilized. The results are compared to results from 300 K simulations and experiments, revealing that Bz*-Bz vibration-vibration IET efficiency increased at low temperatures consistent with longer lived "chattering" collisions at lower temperatures. In the simulations, at the Bz* excitation energy of 150 kcal/mol, the averaged energy transferred per collision, ⟨ΔEc⟩, for Bz*-Bz collisions is found to be ∼2.4 times larger in 140 K than in 300 K bath, whereas this value is ∼1.3 times lower for Bz*-N2 collisions. The overall ⟨ΔEc⟩, for all collisions, is found to be almost two times larger at 140 K compared to the one obtained from the 300 K bath. Such an enhancement of IET efficiency at 140 K is qualitatively consistent with the experimental observation. However, the possible reasons for not attaining a quantitative agreement are discussed. These results imply that the bath temperature and molecular composition as well as the magnitude of vibrational energy of a highly vibrationally excited molecule can shift the overall timescale of rethermalization.
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Affiliation(s)
- Sk Samir Ahamed
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, India
| | - Hyunsik Kim
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Amit K Paul
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, India
| | - Niclas A West
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - Joshua D Winner
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - Diego A Donzis
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - Simon W North
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA
| | - William L Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
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8
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Ahamed SS, Kumar P, Kalita H, Paul AK. Mode‐to‐Mode Collision Energy Transfer from Vibrationally Excited C
6
F
6
to NO/N
2
Mixed Bath with the Development of New Potential Energy Functions. ChemistrySelect 2020. [DOI: 10.1002/slct.202002600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sk. Samir Ahamed
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
| | - Pavan Kumar
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
| | - Hrishikesh Kalita
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
- Department of Chemistry Indian Institute of Technology Guwahati Guwahati Assam 781039 INDIA
| | - Amit K. Paul
- Department of Chemistry National Institute of Technology Meghalaya Shillong Meghalaya 793003 INDIA
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9
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Rivera‐Rivera LA, Wagner AF. Mode‐specific pressure effects on the relaxation of an excited nitromethane molecule in an argon bath. INT J CHEM KINET 2020. [DOI: 10.1002/kin.21415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
| | - Albert F. Wagner
- Chemical Sciences and Engineering Division Argonne National Laboratory Argonne IL 60439 USA
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10
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Jasper AW. “Third‐body” collision parameters for hydrocarbons, alcohols, and hydroperoxides and an effective internal rotor approach for estimating them. INT J CHEM KINET 2020. [DOI: 10.1002/kin.21358] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division Argonne National Laboratory Lemont Illinois
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11
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Guo X, Ma F, Liu C, Niu J, He N, Chen J, Xie HB. Atmospheric oxidation mechanism and kinetics of isoprene initiated by chlorine radicals: A computational study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136330. [PMID: 31931210 DOI: 10.1016/j.scitotenv.2019.136330] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
The reaction with chlorine radicals (·Cl) has been considered to be one of indispensable sinks for isoprene. However, the mechanism of ·Cl initiated isoprene reaction was not fully understood. Herein, the reaction of isoprene with ·Cl, and ensuing reactions of the resulting isoprene relevant radicals were investigated by combined quantum chemistry calculations and kinetics modeling. The results indicate that ·Cl addition to two terminal C-atoms of two double bonds of isoprene, forming IM1-1 and IM1-4, are more favorable than H-abstractions from isoprene. Interestingly, the predicted reaction rate constant for the direct H-abstraction pathway is much lower than that of the indirect one, clarifying a direct H-abstraction mechanism for previously experimental observation. The IM1-1 and IM1-4 have distinct fate in their subsequent transformation. The reaction of IM1-1 ends after the one-time O2 addition. However, IM1-4 can follow auto-oxidation mechanism with two times O2 addition to finally form highly oxidized multi-functional molecules (HOMs), C5H7ClO3 and ·OH. More importantly, the estimated contribution of ·Cl on HOMs (monomer only) formation from isoprene is lower than that of ·OH in addition pathway, implying overall HOMs yield from atmospheric isoprene oxidation could be overestimated if the role of ·Cl in transforming isoprene is ignored.
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Affiliation(s)
- Xirui Guo
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, China
| | - Fangfang Ma
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, China
| | - Cong Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, China
| | - Junfeng Niu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Ning He
- State Key Laboratory of Fine Chemicals & School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, China
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, China.
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12
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Jasper AW. Microcanonical Rate Constants for Unimolecular Reactions in the Low-Pressure Limit. J Phys Chem A 2020; 124:1205-1226. [DOI: 10.1021/acs.jpca.9b10693] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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13
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Ahamed SS, Mahanta H, Paul AK. A Competition between Dissociation Pathway and Energy Transfer Pathway: Unimolecular Dissociation of a Benzene-Hexafluorobenzene Complex in Nitrogen Bath. J Phys Chem A 2019; 123:10663-10675. [PMID: 31755713 DOI: 10.1021/acs.jpca.9b07258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The unimolecular dissociation of a benzene-hexafluorobenzene complex at 1000, 1500, and 2000 K is studied inside a bath of 1000 N2 molecules kept at 300 K using chemical dynamics simulation. Three bath densities of 20, 324, and 750 kg/m3 are considered. The dissociation dynamics of the complex at a 20 kg/m3 bath density is found to be similar to that in the gas phase, whereas the dynamics is drastically different at higher bath densities. The microcanonical/canonical dissociation rate constants for the three bath densities are calculated and fitted to the Arrhenius equation. The activation energies are found to be similar to the gas-phase one. However, the pre-exponential factor is lower and decreases with the increase in bath density. The vibrational degree of freedom of the complex more effectively participates in the collisional energy transfer to the N2 bath, whereas the translational and rotational degrees of freedom of N2 receive the transferred energy. The energy transfer efficiency increases with the increase in bath density. The time scale of the energy transfer pathway is more than that of the dissociation pathway, and negligible direct dissociation of the complex is observed from the simulation at the highest bath density.
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Affiliation(s)
- Sk Samir Ahamed
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
| | - Himashree Mahanta
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
| | - Amit K Paul
- Department of Chemistry , National Institute of Technology Meghalaya , Shillong 793003 , Meghalaya , India
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14
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Jasper AW, Davis MJ. Parameterization Strategies for Intermolecular Potentials for Predicting Trajectory-Based Collision Parameters. J Phys Chem A 2019; 123:3464-3480. [DOI: 10.1021/acs.jpca.9b01918] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Michael J. Davis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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15
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Classical trajectory studies of collisional energy transfer. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-444-64207-3.00003-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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16
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Experiments on collisional energy transfer. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-444-64207-3.00001-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Monte Carlo stochastic simulation of the master equation for unimolecular reaction systems. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-444-64207-3.00007-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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18
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Brown TM, Gillespie BR, Smith CA, Nestler MJ, Heard GL, Setser DW, Holmes BE. Analysis of the Five Unimolecular Reaction Pathways of CD 2ClCHFCl with Emphasis on CD 2Cl(F)C: and CD 2Cl(Cl)C: Formed by 1,1-HCl and 1,1-HF Elimination. J Phys Chem A 2018; 122:8446-8457. [PMID: 30261723 DOI: 10.1021/acs.jpca.8b06680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The five unimolecular HX and DX (X = F, Cl) elimination pathways of CD2ClCHFCl* were examined using a chemical activation technique; the molecules were generated with 92 kcal mol-1 of vibrational energy in a room-temperature bath gas by a combination of CD2Cl and CHFCl radicals. The total unimolecular rate constant was 9.7 × 107 s-1, and branching fractions for each channel were 0.52 (2,1-DCl), 0.29 (1,1-HCl), 0.10 (2,1-DF), 0.07 (1,1-HF), and 0.02 (1,2-HCl). Comparison of the individual experimental rate constants to calculated statistical rate constants gave threshold energies for each process as 63, 72, 66, 73, and 70 kcal mol-1, listed in the same order as the branching fractions. The 1,1-HCl and 1,1-HF reactions gave carbenes, CD2Cl(F)C: and CD2Cl(Cl)C:, respectively, as products, which have hydrogen-bonded complexes with HCl or HF in the exit channel of the potential energy surface. These carbenes have energy in excess of the threshold energy for D atom migration to give CDCl═CDF and CDCl═CDCl, and the subsequent cis-trans isomerization rates of the dihaloethenes can provide information about energy disposal by the 1,1-HX elimination reactions. Electronic structure calculations provide information for transition states of CD2ClCHFCl and hydrogen-bonded complexes of carbenes with HF and HCl. In addition, D atom migration in both free carbenes and in complexes formed by the carbene hydrogen bonding to HCl or HF is explored.
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Affiliation(s)
- Timothy M Brown
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
| | - Blanton R Gillespie
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
| | - Caleb A Smith
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
| | - Matthew J Nestler
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
| | - George L Heard
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
| | - D W Setser
- Kansas State University , Manhattan , Kansas 66506 , United States
| | - Bert E Holmes
- Department of Chemistry , University of North Carolina-Asheville , One University Heights , Asheville , North Carolina 28804 , United States
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19
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Ma F, Ding Z, Elm J, Xie HB, Yu Q, Liu C, Li C, Fu Z, Zhang L, Chen J. Atmospheric Oxidation of Piperazine Initiated by ·Cl: Unexpected High Nitrosamine Yield. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9801-9809. [PMID: 30063348 DOI: 10.1021/acs.est.8b02510] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Chlorine radicals (·Cl) initiated amine oxidation plays an important role for the formation of carcinogenic nitrosamine in the atmosphere. Piperazine (PZ) is considered as a potential atmospheric pollutant since it is an alternative solvent to monoethanolamine (MEA), a benchmark solvent in a leading CO2 capture technology. Here, we employed quantum chemical methods and kinetics modeling to investigate ·Cl-initiated atmospheric oxidation of PZ, particularly concerning the potential of PZ to form nitrosamine compared to MEA. Results showed that the ·Cl-initiated PZ reaction exclusively leads to N-center radicals (PZ-N) that mainly react with NO to produce nitrosamine in their further reaction with O2/NO. Together with the PZ + ·OH reaction, the PZ-N yield from PZ oxidation is still lower than that of the corresponding MEA reactions. However, the nitrosamine yield of PZ is higher than the reported value for MEA when [NO] is <5 ppb, a concentration commonly encountered in a polluted urban atmosphere. The unexpected high nitrosamine yield from PZ compared to MEA results from a more favorable reaction of N-center radicals with NO compared to O2. These findings show that the yield of N-center radicals cannot directly be used as a metric for the yield of the corresponding carcinogenic nitrosamine.
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Affiliation(s)
- Fangfang Ma
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Zhezheng Ding
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Jonas Elm
- Department of Chemistry and Climate , Aarhus University , Aarhus 8000 , Denmark
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Qi Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Cong Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Chao Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment , Northeast Normal University , Changchun 130117 , China
| | - Zhiqiang Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Lili Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China
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20
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Kuwata KT, Luu L, Weberg AB, Huang K, Parsons AJ, Peebles LA, Rackstraw NB, Kim MJ. Quantum Chemical and Statistical Rate Theory Studies of the Vinyl Hydroperoxides Formed in trans-2-Butene and 2,3-Dimethyl-2-butene Ozonolysis. J Phys Chem A 2018; 122:2485-2502. [DOI: 10.1021/acs.jpca.8b00287] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Keith T. Kuwata
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Lina Luu
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Alexander B. Weberg
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Ke Huang
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Austin J. Parsons
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Liam A. Peebles
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Nathan B. Rackstraw
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Min Ji Kim
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
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21
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Macdonald RL, Jaffe RL, Schwenke DW, Panesi M. Construction of a coarse-grain quasi-classical trajectory method. I. Theory and application to N 2-N 2 system. J Chem Phys 2018; 148:054309. [PMID: 29421898 DOI: 10.1063/1.5011331] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This work aims to construct a reduced order model for energy transfer and dissociation in non-equilibrium nitrogen mixtures. The objective is twofold: to present the Coarse-Grain Quasi-Classical Trajectory (CG-QCT) method, a novel framework for constructing a reduced order model for diatom-diatom systems; and to analyze the physics of non-equilibrium relaxation of the nitrogen molecules undergoing dissociation in an ideal chemical reactor. The CG-QCT method couples the construction of the reduced order model under the coarse-grain model framework with the quasi-classical trajectory calculations to directly construct the reduced model without the need for computing the individual rovibrational specific kinetic data. In the coarse-grain model, the energy states are lumped together into groups containing states with similar properties, and the distribution of states within each of these groups is prescribed by a Boltzmann distribution at the local translational temperature. The required grouped kinetic properties are obtained directly by the QCT calculations. Two grouping strategies are considered: energy-based grouping, in which states of similar internal energy are lumped together, and vibrational grouping, in which states with the same vibrational quantum number are grouped together. A zero-dimensional chemical reactor simulation, in which the molecules are instantaneously heated, forcing the system into strong non-equilibrium, is used to study the differences between the two grouping strategies. The comparison of the numerical results against available experimental data demonstrates that the energy-based grouping is more suitable to capture dissociation, while the energy transfer process is better described with a vibrational grouping scheme. The dissociation process is found to be strongly dependent on the behavior of the high energy states, which contribute up to 50% of the dissociating molecules. Furthermore, up to 40% of the energy required to dissociate the molecules comes from the rotational mode, underscoring the importance of accounting for this mode when constructing non-equilibrium kinetic models. In contrast, the relaxation process is governed primarily by low energy states, which exhibit significantly slower transitions in the vibrational binning model due to the prevalence of mode separation in these states.
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Affiliation(s)
- R L Macdonald
- University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - R L Jaffe
- NASA Ames Research Center, Moffet Field, California 94035, USA
| | - D W Schwenke
- NASA Ames Research Center, Moffet Field, California 94035, USA
| | - M Panesi
- University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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22
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Mazarei E, Mousavipour SH. A Theoretical Study on the Dynamics of the Reaction of CH Radicals with Water. J Phys Chem A 2017; 121:8033-8047. [DOI: 10.1021/acs.jpca.7b05504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elham Mazarei
- Department of Chemistry,
College of Science, Shiraz University, Shiraz, Iran
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23
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Fittschen C, Assaf E, Vereecken L. Experimental and Theoretical Investigation of the Reaction NO + OH + O2 → HO2 + NO2. J Phys Chem A 2017; 121:4652-4657. [DOI: 10.1021/acs.jpca.7b02499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Christa Fittschen
- Université
Lille, CNRS, UMR 8522 - PC2A -Physicochimie des Processus de Combustion et de l′Atmosphère, F-59000 Lille, France
| | - Emmanuel Assaf
- Université
Lille, CNRS, UMR 8522 - PC2A -Physicochimie des Processus de Combustion et de l′Atmosphère, F-59000 Lille, France
| | - Luc Vereecken
- Forschungszentrum
Jülich GmbH, Institut für Energie und Klimaforschung, 52428 Jülich, Germany
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24
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Xie HB, Ma F, Yu Q, He N, Chen J. Computational Study of the Reactions of Chlorine Radicals with Atmospheric Organic Compounds Featuring NHx–π-Bond (x = 1, 2) Structures. J Phys Chem A 2017; 121:1657-1665. [DOI: 10.1021/acs.jpca.6b11418] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hong-Bin Xie
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Fangfang Ma
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Qi Yu
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Ning He
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory
of Industrial Ecology and Environmental Engineering (Ministry of Education),
School of Environmental Science and Technology and ‡State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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25
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Bao JL, Truhlar DG. Variational transition state theory: theoretical framework and recent developments. Chem Soc Rev 2017; 46:7548-7596. [DOI: 10.1039/c7cs00602k] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This article reviews the fundamentals of variational transition state theory (VTST), its recent theoretical development, and some modern applications.
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Affiliation(s)
- Junwei Lucas Bao
- Department of Chemistry
- Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
| | - Donald G. Truhlar
- Department of Chemistry
- Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
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26
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Sun J, Shao Y, Wu W, Tang Y, Zhang Y, Hu Y, Liu J, Yi H, Chen F, Cheng Y. A quantum chemical study on ˙Cl-initiated atmospheric degradation of acrylonitrile. RSC Adv 2017. [DOI: 10.1039/c7ra01521f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Degradation of acrylonitrile (CH2CHCN) by reaction with atomic chlorine was studied using quantum chemical methods.
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27
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West NA, Winner JD, Bowersox RDW, North SW. Resolving the energy and temperature dependence of C6H6∗ collisional relaxation via time-dependent bath temperature measurements. J Chem Phys 2016; 145:014308. [DOI: 10.1063/1.4954896] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Niclas A. West
- Department of Chemistry, Texas A&M University, 3012 TAMU, College Station, Texas 77842, USA
| | - Joshua D. Winner
- Department of Chemistry, Texas A&M University, 3012 TAMU, College Station, Texas 77842, USA
| | - Rodney D. W. Bowersox
- Department of Aerospace Engineering, Texas A&M University, 3141 TAMU, College Station, Texas 77842, USA
| | - Simon W. North
- Department of Chemistry, Texas A&M University, 3012 TAMU, College Station, Texas 77842, USA
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28
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Ryazantsev MN, Jamal A, Maeda S, Morokuma K. Global investigation of potential energy surfaces for the pyrolysis of C(1)-C(3) hydrocarbons: toward the development of detailed kinetic models from first principles. Phys Chem Chem Phys 2016; 17:27789-805. [PMID: 26434394 DOI: 10.1039/c5cp04329h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Detailed kinetic models (DKMs) are the most fundamental "bottom-up" approaches to computational investigation of the pyrolysis and oxidation of fuels. The weakest points of existing DKMs are incomplete information about the reaction types that can be involved in the potential energy surfaces (PESs) in pyrolysis and oxidation processes. Also, the computational thermodynamic parameters available in the literature vary widely with the level of theory employed. More sophisticated models require improvement both in our knowledge of the type of the reactions involved and the consistency of thermodynamic and kinetic parameters. In this paper, we aim to address these issues by developing ab initio models that can be used to describe early stages of pyrolysis of C1-C3 hydrocarbons. We applied a recently developed global reaction route mapping (GRRM) strategy to systematically investigate the PES of the pyrolysis of C1-C3 hydrocarbons at a consistent level of theory. The reactions are classified into 14 reaction types. The critical points on the PES for all reactions in the network are calculated at the highly accurate UCCSD(T)-F12b/cc-pVTZ//UM06-2X/cc-pVTZ level of theory. The data reported in this paper can be used for first principle calculations of kinetic constants and for a subsequent study on modeling the evolution of the species from the reaction network of the pyrolysis and oxidation of C1-C3 hydrocarbons.
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Affiliation(s)
- Mikhail N Ryazantsev
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA.
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29
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Babikov D, Semenov A. Recent Advances in Development and Applications of the Mixed Quantum/Classical Theory for Inelastic Scattering. J Phys Chem A 2015; 120:319-31. [DOI: 10.1021/acs.jpca.5b09569] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitri Babikov
- Chemistry
Department, Wehr
Chemistry Building, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Alexander Semenov
- Chemistry
Department, Wehr
Chemistry Building, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
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30
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Xie HB, Ma F, Wang Y, He N, Yu Q, Chen J. Quantum Chemical Study on ·Cl-Initiated Atmospheric Degradation of Monoethanolamine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13246-55. [PMID: 26495768 DOI: 10.1021/acs.est.5b03324] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Recent findings on the formation of ·Cl in continental urban areas necessitate the consideration of ·Cl initiated degradation when assessing the fate of volatile organic pollutants. Monoethanolamine (MEA) is considered as a potential atmospheric pollutant since it is a benchmark and widely utilized solvent in a leading CO2 capture technology. Especially, ·Cl may have specific interactions with the N atom of MEA, which could make the MEA + ·Cl reaction have different pathways and products from those of the MEA + ·OH reaction. Hence, ·Cl initiated reactions with MEA were investigated by a quantum chemical method [CCSD(T)/aug-cc-pVTZ//MP2/6-31+G(3df,2p)] and kinetics modeling. Results show that the overall rate constant for ·Cl initiated H-abstraction of MEA is 5 times faster than that initiated by ·OH, and the tropospheric lifetimes of MEA will be overestimated by 6-46% when assuming that [·Cl]/[·OH] = 1-10% if the role of ·Cl is ignored. The MEA + ·Cl reaction exclusively produces MEA-N that finally transforms into several products including mutagenic nitramine and carcinogenic nitrosamine via further reactions with O2/NOx, and the contribution of ·Cl to their formation is about 25-250% of that of ·OH. Thus, it is necessary to consider ·Cl initiated tropospheric degradation of MEA for its risk assessment.
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Affiliation(s)
- Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Fangfang Ma
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Yuanfang Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Ning He
- State Key Laboratory of Fine Chemicals, Dalian University of Technology , Dalian 116024, China
| | - Qi Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
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31
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Kuwata KT, Guinn EJ, Hermes MR, Fernandez JA, Mathison JM, Huang K. A Computational Re-examination of the Criegee Intermediate–Sulfur Dioxide Reaction. J Phys Chem A 2015; 119:10316-35. [DOI: 10.1021/acs.jpca.5b06565] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Keith T. Kuwata
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Emily J. Guinn
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Matthew R. Hermes
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Jenna A. Fernandez
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Jon M. Mathison
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
| | - Ke Huang
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, United States
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32
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Brown TM, Nestler MJ, Rossabi SM, Heard GL, Setser DW, Holmes BE. Characterization of the 1,1-HCl Elimination Reaction of Vibrationally Excited CD3CHFCl Molecules and Assignment of Threshold Energies for 1,1-HCl and 1,2-DCl plus 1,1-HF and 1,2-DF Elimination Reactions. J Phys Chem A 2015; 119:9441-51. [PMID: 26291380 DOI: 10.1021/acs.jpca.5b06638] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vibrationally excited CD3CHFCl molecules with 96 kcal mol(-1) of energy were generated by the recombination of CD3 and CHFCl radicals in a room-temperature bath gas. The four competing unimolecular decomposition reactions, namely, 1,1-HCl and 1,2-DCl elimination and 1,1-HF and 1,2-DF elimination, were observed, and the individual rate constants were measured. The product branching fractions are 0.60, 0.27, 0.09, and 0.04 for 1,2-DCl, 1,1-HCl, 1,2-DF, and 1,1-HF elimination, respectively. Electronic structure calculations were used to define models of the four transition states. The statistical rate constants calculated from these models were compared to the experimental rate constants. The assigned threshold energies with ±2 kcal mol(-1) uncertainty are 60, 72, 65, and 74 kcal mol(-1) for the 1,2-DCl, 1,1-HCl, 1,2-DF, and 1,1-HF reactions, respectively. The loose structure of the 1,1-HX transition states, which is exemplified by the order of magnitude larger pre-exponential factor relative to the 1,2-HX elimination reactions, compensates for the high threshold energy; thus, the 1,1-HX elimination reaction rates can compete with the 1,2-HX elimination reactions for high levels of vibrational excitation in CD3CHFCl. The 1,1-HCl and 1,1-HF reactions are observed via the CD2═CDF and CD2═CDCl products formed from isomerization of the CD3CF and CD3CCl carbenes. These D-atom migration reactions are discussed, and the possibility of tunneling is evaluated. The transition states developed from the 1,1-HCl and 1,1-HF reactions of CD3CHFCl are compared to models for the HCl and HF elimination reactions of CHF2Cl, CHFCl2, and CH2FCl.
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Affiliation(s)
- Timothy M Brown
- Department of Chemistry, University of North Carolina-Asheville , One University Heights, Asheville, North Carolina 28804-8511, United States and
| | - Matthew J Nestler
- Department of Chemistry, University of North Carolina-Asheville , One University Heights, Asheville, North Carolina 28804-8511, United States and
| | - Samuel M Rossabi
- Department of Chemistry, University of North Carolina-Asheville , One University Heights, Asheville, North Carolina 28804-8511, United States and
| | - George L Heard
- Department of Chemistry, University of North Carolina-Asheville , One University Heights, Asheville, North Carolina 28804-8511, United States and
| | - D W Setser
- Kansas State University , Manhattan, Kansas 66506, United States
| | - Bert E Holmes
- Department of Chemistry, University of North Carolina-Asheville , One University Heights, Asheville, North Carolina 28804-8511, United States and
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33
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Conte R, Houston PL, Bowman JM. Trajectory and Model Studies of Collisions of Highly Excited Methane with Water Using an ab Initio Potential. J Phys Chem A 2015; 119:12304-17. [DOI: 10.1021/acs.jpca.5b06595] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Riccardo Conte
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Paul L. Houston
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Department
of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, New York 14852, United States
| | - Joel M. Bowman
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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34
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Houston PL, Conte R, Bowman JM. A Model For Energy Transfer in Collisions of Atoms with Highly Excited Molecules. J Phys Chem A 2015; 119:4695-710. [DOI: 10.1021/acs.jpca.5b00219] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul L. Houston
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Riccardo Conte
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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35
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Vereecken L, Glowacki DR, Pilling MJ. Theoretical Chemical Kinetics in Tropospheric Chemistry: Methodologies and Applications. Chem Rev 2015; 115:4063-114. [DOI: 10.1021/cr500488p] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Luc Vereecken
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - David R. Glowacki
- PULSE
Institute and Department of Chemistry, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
- Department
of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom
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36
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Rivera-Rivera LA, Wagner AF, Sewell TD, Thompson DL. Pressure effects on the relaxation of an excited nitromethane molecule in an argon bath. J Chem Phys 2015; 142:014303. [PMID: 25573557 DOI: 10.1063/1.4904314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Classical molecular dynamics simulations were performed to study the relaxation of nitromethane in an Ar bath (of 1000 atoms) at 300 K and pressures 10, 50, 75, 100, 125, 150, 300, and 400 atm. The molecule was instantaneously excited by statistically distributing 50 kcal/mol among the internal degrees of freedom. At each pressure, 1000 trajectories were integrated for 1000 ps, except for 10 atm, for which the integration time was 5000 ps. The computed ensemble-averaged rotational energy decay is ∼100 times faster than the vibrational energy decay. Both rotational and vibrational decay curves can be satisfactorily fit with the Lendvay-Schatz function, which involves two parameters: one for the initial rate and one for the curvature of the decay curve. The decay curves for all pressures exhibit positive curvature implying the rate slows as the molecule loses energy. The initial rotational relaxation rate is directly proportional to density over the interval of simulated densities, but the initial vibrational relaxation rate decreases with increasing density relative to the extrapolation of the limiting low-pressure proportionality to density. The initial vibrational relaxation rate and curvature are fit as functions of density. For the initial vibrational relaxation rate, the functional form of the fit arises from a combinatorial model for the frequency of nitromethane "simultaneously" colliding with multiple Ar atoms. Roll-off of the initial rate from its low-density extrapolation occurs because the cross section for collision events with L Ar atoms increases with L more slowly than L times the cross section for collision events with one Ar atom. The resulting density-dependent functions of the initial rate and curvature represent, reasonably well, all the vibrational decay curves except at the lowest density for which the functions overestimate the rate of decay. The decay over all gas phase densities is predicted by extrapolating the fits to condensed-phase densities.
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Affiliation(s)
- Luis A Rivera-Rivera
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211-7600, USA
| | - Albert F Wagner
- Argonne National Laboratory, Chemical Sciences and Engineering Division, Argonne, Illinois 60439, USA
| | - Thomas D Sewell
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211-7600, USA
| | - Donald L Thompson
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211-7600, USA
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37
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Kim K, Johnson AM, Powell AL, Mitchell DG, Sevy ET. High resolution IR diode laser study of collisional energy transfer between highly vibrationally excited monofluorobenzene and CO2: the effect of donor fluorination on strong collision energy transfer. J Chem Phys 2014; 141:234306. [PMID: 25527934 DOI: 10.1063/1.4903252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Collisional energy transfer between vibrational ground state CO2 and highly vibrationally excited monofluorobenzene (MFB) was studied using narrow bandwidth (0.0003 cm(-1)) IR diode laser absorption spectroscopy. Highly vibrationally excited MFB with E' = ∼41,000 cm(-1) was prepared by 248 nm UV excitation followed by rapid radiationless internal conversion to the electronic ground state (S1→S0*). The amount of vibrational energy transferred from hot MFB into rotations and translations of CO2 via collisions was measured by probing the scattered CO2 using the IR diode laser. The absolute state specific energy transfer rate constants and scattering probabilities for single collisions between hot MFB and CO2 were measured and used to determine the energy transfer probability distribution function, P(E,E'), in the large ΔE region. P(E,E') was then fit to a bi-exponential function and extrapolated to the low ΔE region. P(E,E') and the biexponential fit data were used to determine the partitioning between weak and strong collisions as well as investigate molecular properties responsible for large collisional energy transfer events. Fermi's Golden rule was used to model the shape of P(E,E') and identify which donor vibrational motions are primarily responsible for energy transfer. In general, the results suggest that low-frequency MFB vibrational modes are primarily responsible for strong collisions, and govern the shape and magnitude of P(E,E'). Where deviations from this general trend occur, vibrational modes with large negative anharmonicity constants are more efficient energy gateways than modes with similar frequency, while vibrational modes with large positive anharmonicity constants are less efficient at energy transfer than modes of similar frequency.
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Affiliation(s)
- Kilyoung Kim
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
| | - Alan M Johnson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
| | - Amber L Powell
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
| | - Deborah G Mitchell
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
| | - Eric T Sevy
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
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38
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Baptista L, da Silveira EF. A theoretical study of three gas-phase reactions involving the production or loss of methane cations. Phys Chem Chem Phys 2014; 16:21867-75. [PMID: 25200833 DOI: 10.1039/c4cp02607a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrocarbon ions are important species in flames, spectroscopy and the interstellar medium. Their importance is reflected in the extensive body of literature on the structure and reactivity of carbocations. However, the geometry, electronic structure and reactivity of carbocations are difficult to assess. This study aims to contribute to the current knowledge of this subject by presenting a quantum mechanics description of methane cation dissociation using multiconfigurational methods. The geometric and electronic parameters of the minimum structure were determined for three main reaction paths: the dissociation CH4(+)→ CH2(+) + H2 and the dissociation-recombination processes CH4(+)↔ CH3(+) + H. The electronic and energetic effects of these reactions were analyzed, and it was found that each reaction path has a strong dependence on the methodology used as well as a strong multiconfigurational character during dissociation. The first doublet excited states are inner-shell excited states and may correspond to the ions that are expected to be formed after electron detachment. The rate coefficient for each reaction path was determined using variational transition state theory and RRKM/master equation calculations. The major dissociation paths, with their rate coefficients at the high-pressure limit, are CH4(+)(X(~)(2)B1) → CH3(+)(A(2)A1') + H((2)S) (k∞(T) = 1.42 × 10(+14) s(-1) exp(-37.12/RT)) and CH4(+)(X(~)(2)B1) → CH2(+)(A(2)A1) + H2((2)Σg(+)) (k∞(T) = 9.18 × 10(+14) s(-1) exp(-55.77/RT)). Our findings help to explain the abundance of ions formed from CH4 in the interstellar medium and to build models of chemical evolution.
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Affiliation(s)
- Leonardo Baptista
- Universidade do Estado do Rio de Janeiro, Faculdade de Tecnologia, Departamento de Química e Ambiental, Rodovia Presidente Dutra Km 298, Resende, RJ, Brazil.
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Houston PL, Conte R, Bowman JM. Collisional Energy Transfer in Highly Excited Molecules. J Phys Chem A 2014; 118:7758-75. [DOI: 10.1021/jp506202g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul L. Houston
- School of Chemistry
and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
- Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14852, United States
| | - Riccardo Conte
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department
of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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40
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Paul AK, Kohale SC, Pratihar S, Sun R, North SW, Hase WL. A unified model for simulating liquid and gas phase, intermolecular energy transfer: N2+ C6F6collisions. J Chem Phys 2014; 140:194103. [DOI: 10.1063/1.4875516] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Rissanen MP, Eskola AJ, Nguyen TL, Barker JR, Liu J, Liu J, Halme E, Timonen RS. CH2NH2 + O2 and CH3CHNH2 + O2 Reaction Kinetics: Photoionization Mass Spectrometry Experiments and Master Equation Calculations. J Phys Chem A 2014; 118:2176-86. [DOI: 10.1021/jp411238e] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matti P. Rissanen
- Laboratory
of Physical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
- Division
of Atmospheric Sciences, Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland
| | - Arkke J. Eskola
- Laboratory
of Physical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Thanh Lam Nguyen
- Department of Chemistry & Biochemistry, The University of Texas at Austin, Texas 78712-0165, United States
| | - John R. Barker
- Department
of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143, United States
| | - Jingjing Liu
- Institute
of Theoretical Chemistry, State Key Laboratory of Theoretical and
Computational Chemistry, Jilin University, Changchun 130023, China
| | - Jingyao Liu
- Institute
of Theoretical Chemistry, State Key Laboratory of Theoretical and
Computational Chemistry, Jilin University, Changchun 130023, China
| | - Erkki Halme
- Laboratory
of Physical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Raimo S. Timonen
- Laboratory
of Physical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
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42
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Weston RE, Nguyen TL, Stanton JF, Barker JR. HO + CO Reaction Rates and H/D Kinetic Isotope Effects: Master Equation Models with ab Initio SCTST Rate Constants. J Phys Chem A 2013; 117:821-35. [DOI: 10.1021/jp311928w] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ralph E. Weston
- Department
of Chemistry, Brookhaven National Laboratory, Upton, New York 11973,
United States
| | - Thanh Lam Nguyen
- Department
of Chemistry and
Biochemistry, The University of Texas,
Austin, Texas 78712-0165, United States
| | - John F. Stanton
- Department
of Chemistry and
Biochemistry, The University of Texas,
Austin, Texas 78712-0165, United States
| | - John R. Barker
- Department of Atmospheric, Oceanic,
and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143, United States
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43
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Wang SY, Zhang B, Zhu DH, Dai K, Shen YF. Energy-dependence of vibrational relaxation between highly vibrationally excited KH (X1Σ+, ν"=14-23) and H2, and N2. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 96:517-525. [PMID: 22728970 DOI: 10.1016/j.saa.2012.05.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 05/05/2012] [Accepted: 05/21/2012] [Indexed: 06/01/2023]
Abstract
Vibrational state total relaxation rate coefficients, k(ν") (M), for KH (ν"=14-23) by M=H(2) and N(2) have been investigated in an overtone pump-probe configuration. At ν"=14, 15, 16 and 17, the rate coefficients k(ν)(″) (M) increase linearly with vibrational quantum number. The region (ν"=18, 19, 20 and 21) where the dependence is much stronger than linear has significant contribution from multiquantum (Δν≥2) relaxation. For ν"=18, 19, 20 and 21, 0.25, 0.31, 0.38 and 0.31 of the initially prepared population undergo two-quantum (Δν=2) vibrational relaxation in KH (ν")+H(2) collisions. In KH (ν")+N(2), the time profile of ν"=14(15) after preparation of ν"=19(20) was measured. A clear bimodal distribution is observed. The time scale of the first peak is much shorter than the known collisional lifetimes of the intervening vibrational levels and thus a sequential single-quantum relaxation mechanism can be explicitly ruled out. Relaxation of KD with D(2) has been also investigated. The relaxation rate coefficients exhibit distinct maxima for both isotopes (KH and KD). We discuss possible explanation of the experimental results including mass effect, V-R energy transfer and V-V energy transfer.
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Affiliation(s)
- Shu-ying Wang
- School of Science, Xi'an Jiaotong University, Xi'an 710049, China.
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Andrews DU, Heazlewood BR, Maccarone AT, Conroy T, Payne RJ, Jordan MJT, Kable SH. Photo-Tautomerization of Acetaldehyde to Vinyl Alcohol: A Potential Route to Tropospheric Acids. Science 2012; 337:1203-6. [DOI: 10.1126/science.1220712] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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45
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Bozkaya U, Turney JM, Yamaguchi Y, Schaefer HF. The lowest-lying electronic singlet and triplet potential energy surfaces for the HNO–NOH system: Energetics, unimolecular rate constants, tunneling and kinetic isotope effects for the isomerization and dissociation reactions. J Chem Phys 2012; 136:164303. [DOI: 10.1063/1.4704895] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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46
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Golden DM. The Reaction OH + C2H4: An Example of Rotational Channel Switching. J Phys Chem A 2012; 116:4259-66. [DOI: 10.1021/jp302009t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David M. Golden
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United
States
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47
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Kislov VV, Mebel AM, Aguilera-Iparraguirre J, Green WH. Reaction of Phenyl Radical with Propylene as a Possible Source of Indene and Other Polycyclic Aromatic Hydrocarbons: An Ab Initio/RRKM-ME Study. J Phys Chem A 2012; 116:4176-91. [DOI: 10.1021/jp212338g] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- V. V. Kislov
- Department of Chemistry and Biochemistry, Florida International University, Miami,
Florida 33199, United States
| | - A. M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami,
Florida 33199, United States
| | - J. Aguilera-Iparraguirre
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,
United States
| | - W. H. Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,
United States
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Hsu HC, Tsai MT, Dyakov YA, Ni CK. Alkylation effects on the energy transfer of highly vibrationally excited naphthalene. Chem Asian J 2011; 6:3048-53. [PMID: 21780292 DOI: 10.1002/asia.201100314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Indexed: 11/06/2022]
Abstract
The energy transfer of highly vibrationally excited isomers of dimethylnaphthalene and 2-ethylnaphthalene in collisions with krypton were investigated using crossed molecular beam/time-of-flight mass spectrometer/time-sliced velocity map ion imaging techniques at a collision energy of approximately 300 cm(-1). Angular-resolved energy-transfer distribution functions were obtained directly from the images of inelastic scattering. The results show that alkyl-substituted naphthalenes transfer more vibrational energy to translational energy than unsubstituted naphthalene. Alkylation enhances the V→T energy transfer in the range -ΔE(d)=-100~-1500 cm(-1) by approximately a factor of 2. However, the maximum values of V→T energy transfer for alkyl-substituted naphthalenes are about 1500~2000 cm(-1), which is similar to that of naphthalene. The lack of rotation-like wide-angle motion of the aromatic ring and no enhancement in very large V→T energy transfer, like supercollisions, indicates that very large V→T energy transfer requires special vibrational motions. This transfer cannot be achieved by the low-frequency vibrational motions of alkyl groups.
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Affiliation(s)
- Hsu Chen Hsu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
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49
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Chen Hsu H, Tsai MT, Dyakov YA, Ni CK. Energy transfer of highly vibrationally excited naphthalene: Collisions with CHF3, CF4, and Kr. J Chem Phys 2011; 135:054311. [DOI: 10.1063/1.3622765] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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50
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