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Hata H, Tonokura K. Kinetic study of isoprene hydroxy hydroperoxide radicals reacting with sulphur dioxide and their global-scale impact on sulphate formation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 38856669 DOI: 10.1039/d4em00232f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Isoprene is the most relevant volatile organic compound emitted during the biosynthesis of metabolism processes. The oxidation of isoprene by a hydroxy radical (OH) is one of the main consumption schemes that generate six isomers of isoprene hydroxy hydroperoxide radicals (ISOPOOs). In this study, the rate constants of ISOPOOs + sulphur dioxide (SO2) reactions that eventually generate sulphur trioxide (SO3), the precursor of sulphate aerosol (SO42-(p)), are determined using microcanonical kinetic theories coupled with molecular structures and energies estimated by quantum chemical calculations. The results show that the reaction rates range from 10-27 to 10-20 cm3 molecule-1 s-1, depending on the atmospheric temperature and structure of the six ISOPOO isomers. The effect of SO3 formation from SO2 oxidation by ISOPOOs on the atmosphere is evaluated by a global chemical transport model, along with the rate constants obtained from microcanonical kinetic theories. The results show that SO3 formation is enhanced in regions with high SO2 or low nitrogen oxide (NO), such as China, the Middle East, and Amazon rainforests. However, the production rates of SO3 formation by ISOPOOs + SO2 reactions are eight orders of magnitude lower than that from the OH + SO2 reaction. This is indicative of SO42-(p) formation from the direct oxidation of SO2 by ISOPOOs, which is almost negligible in the atmosphere. The results of this study entail a detailed analysis of SO3 formation from gas-phase reactions of isoprene-derived products.
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Affiliation(s)
- Hiroo Hata
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
| | - Kenichi Tonokura
- Department of Environment Systems, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwano-ha, Kashiwa, Chiba 277-8563, Japan
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2
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Zhang ZP, Wang SH, Shang YL, Liu JH, Luo SN. Theoretical Study on Ethylamine Dissociation Reactions Using VRC-VTST and SS-QRRK Methods. J Phys Chem A 2024; 128:2191-2199. [PMID: 38456900 DOI: 10.1021/acs.jpca.3c08373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Barrierless bond dissociation reactions play an important role in fuel combustion. In this work, the pressure-dependent dissociation rate constants of ethylamine (EA) are accurately determined using variable-reaction-coordinate variational transition-state theory combined with the system-specific quantum Rice-Ramsperger-Kassel method. Before the kinetics calculations, the performances of four density functional theory methods in describing the bond dissociation of EA are evaluated against the benchmark method, FIC-MRCISD(T)+Q/cc-pVTZ, and the MN15-L/cc-pVTZ method is the best choice. By comparison of the Gibbs free energies and the rate constants for the bond dissociation reactions of EA, ethanol, and propane, the influence of functional groups on the reaction kinetics is discussed. The kinetics calculations show that the dissociation rate constants of EA are sensitive to pressure at low pressures and high temperatures, and the dominant channel is the reaction that yields C2H5 and NH2 radicals. A literature combustion model of EA is updated with our calculations, and the satisfactory agreement between the model predictions and reported ignition delay times of EA suggests the reliability of our calculations.
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Affiliation(s)
- Z P Zhang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
- Dynamic Materials Data Science Center, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
| | - S H Wang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
- Dynamic Materials Data Science Center, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
| | - Y L Shang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
- Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, P. R. China
- The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610027, P. R. China
- Dynamic Materials Data Science Center, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
| | - J H Liu
- Chengdu JiangDe Technology Co., Ltd, Chengdu, Sichuan 610100, P. R. China
| | - S N Luo
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
- Dynamic Materials Data Science Center, Southwest Jiaotong University, Chengdu, Sichuan 610031, P. R. China
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3
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Döntgen M, Wildenberg A, Heufer KA. Theoretical Investigation of Key Properties of the Pyrolysis of Methyl, Ethyl, and Dimethyl Dioxolane Isomers. J Phys Chem A 2022; 126:8326-8336. [DOI: 10.1021/acs.jpca.2c06564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Malte Döntgen
- Chair of High Pressure Gas Dynamics, Shock Wave Laboratory, RWTH Aachen University, 52056Aachen, Germany
| | - Alina Wildenberg
- Chair of High Pressure Gas Dynamics, Shock Wave Laboratory, RWTH Aachen University, 52056Aachen, Germany
| | - K. Alexander Heufer
- Chair of High Pressure Gas Dynamics, Shock Wave Laboratory, RWTH Aachen University, 52056Aachen, Germany
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4
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Ben-Tal Y, Boaler PJ, Dale HJA, Dooley RE, Fohn NA, Gao Y, García-Domínguez A, Grant KM, Hall AMR, Hayes HLD, Kucharski MM, Wei R, Lloyd-Jones GC. Mechanistic analysis by NMR spectroscopy: A users guide. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 129:28-106. [PMID: 35292133 DOI: 10.1016/j.pnmrs.2022.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
A 'principles and practice' tutorial-style review of the application of solution-phase NMR in the analysis of the mechanisms of homogeneous organic and organometallic reactions and processes. This review of 345 references summarises why solution-phase NMR spectroscopy is uniquely effective in such studies, allowing non-destructive, quantitative analysis of a wide range of nuclei common to organic and organometallic reactions, providing exquisite structural detail, and using instrumentation that is routinely available in most chemistry research facilities. The review is in two parts. The first comprises an introduction to general techniques and equipment, and guidelines for their selection and application. Topics include practical aspects of the reaction itself, reaction monitoring techniques, NMR data acquisition and processing, analysis of temporal concentration data, NMR titrations, DOSY, and the use of isotopes. The second part comprises a series of 15 Case Studies, each selected to illustrate specific techniques and approaches discussed in the first part, including in situ NMR (1/2H, 10/11B, 13C, 15N, 19F, 29Si, 31P), kinetic and equilibrium isotope effects, isotope entrainment, isotope shifts, isotopes at natural abundance, scalar coupling, kinetic analysis (VTNA, RPKA, simulation, steady-state), stopped-flow NMR, flow NMR, rapid injection NMR, pure shift NMR, dynamic nuclear polarisation, 1H/19F DOSY NMR, and in situ illumination NMR.
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Affiliation(s)
- Yael Ben-Tal
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Patrick J Boaler
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Harvey J A Dale
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Ruth E Dooley
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom; Evotec (UK) Ltd, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, United Kingdom
| | - Nicole A Fohn
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Yuan Gao
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Andrés García-Domínguez
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Katie M Grant
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Andrew M R Hall
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Hannah L D Hayes
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Maciej M Kucharski
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Ran Wei
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Guy C Lloyd-Jones
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom.
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5
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Loukhovitski BI, Sharipov AS. Molecular Collision Diameters and Electronic Polarizabilities: Inherent Relationship and Fast Evaluation. J Phys Chem A 2021; 125:5117-5123. [PMID: 34077208 DOI: 10.1021/acs.jpca.1c02201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The collision diameter σ for a large set of molecular species is related to the static electronic polarizability αel. A remarkable correlation between these quantities conceptually similar to the analogous one previously identified for atoms is revealed. Our recommended model is the function σ(αel) = p1 + p2αel1/3, where p1 = 0.768 Å and p2 = 2.168 are the fitting parameters providing the best overall match to the reference data for collision diameter (181 data points). The obtained correlation allows one to easily find the collision diameter of molecules from the known polarizability and vice versa. These findings can be useful for many applications, where there is a need for inexpensive assessments of the collision diameters or electronic polarizabilities, for example, when developing the transport property databases for modeling of chemically reacting flows.
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Seif A, Domingo LR, Mazarei E, Zahedi E, Ahmadi TS. Atmospheric Oxidation Reactions of Methyl Salicylate as Green Leaf Volatiles by OH Radical: Theoretical Kinetics and Mechanism. ChemistrySelect 2020. [DOI: 10.1002/slct.202003286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ahmad Seif
- Department of Chemistry Central Tehran Branch Islamic Azad University Tehran Iran
- Department of Organic Chemistry University of Valencia, Dr. Moliner 50 46100 Burjassot Valencia Spain
| | - Luis Ramon Domingo
- Department of Organic Chemistry University of Valencia, Dr. Moliner 50 46100 Burjassot Valencia Spain
| | - Elham Mazarei
- Department of Organic Chemistry University of Valencia, Dr. Moliner 50 46100 Burjassot Valencia Spain
| | - Ehsan Zahedi
- Department of Chemistry Shahrood Branch Islamic Azad University Shahrood Iran
| | - Temer Shah Ahmadi
- Department of Organic Chemistry University of Valencia, Dr. Moliner 50 46100 Burjassot Valencia Spain
- Department of Chemistry Villanova University Villanova PA 19085 USA
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7
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Pearce BKD, Ayers PW, Pudritz RE. CRAHCN-O: A Consistent Reduced Atmospheric Hybrid Chemical Network Oxygen Extension for Hydrogen Cyanide and Formaldehyde Chemistry in CO 2-, N 2-, H 2O-, CH 4-, and H 2-Dominated Atmospheres. J Phys Chem A 2020; 124:8594-8606. [PMID: 32961050 DOI: 10.1021/acs.jpca.0c06804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydrogen cyanide (HCN) and formaldehyde (H2CO) are key precursors to biomolecules such as nucleobases and amino acids in planetary atmospheres. However, many reactions which produce and destroy these species in atmospheres containing CO2 and H2O are still missing from the literature. We use a quantum chemistry approach to find these missing reactions and calculate their rate coefficients using canonical variational transition state theory and Rice-Ramsperger-Kassel-Marcus/master equation theory at the BHandHLYP/aug-cc-pVDZ level of theory. We calculate the rate coefficients for 126 total reactions and validate our calculations by comparing with experimental data in the 39% of available cases. Our calculated rate coefficients are most frequently within a factor of 2 of experimental values and generally always within an order of magnitude of these values. We discover 45 previously unknown reactions and identify 6 from this list that are most likely to dominate H2CO and HCN production and destruction in planetary atmospheres. We highlight 1O + CH3 → H2CO + H as a new key source and H2CO + 1O → HCO + OH as a new key sink, for H2CO in upper planetary atmospheres. In this effort, we develop an oxygen extension to our consistent reduced atmospheric hybrid chemical network (CRAHCN-O), building off our previously developed network for HCN production in N2-, CH4-, and H2-dominated atmospheres (CRAHCN). This extension can be used to simulate both HCN and H2CO production in atmospheres dominated by any of CO2, N2, H2O, CH4, and H2.
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Affiliation(s)
- Ben K D Pearce
- Origins Institute and Department of Physics and Astronomy, McMaster University, ABB 241, 1280 Main Street, Hamilton, Ontario L8S 4M1, Canada
| | - Paul W Ayers
- Origins Institute and Department of Chemistry and Chemical Biology, McMaster University, ABB 156, 1280 Main Street, Hamilton, Ontario L8S 4M1, Canada
| | - Ralph E Pudritz
- Origins Institute and Department of Physics and Astronomy, McMaster University, ABB 241, 1280 Main Street, Hamilton, Ontario L8S 4M1, Canada
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8
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Sharipov AS, Loukhovitski BI. Small atomic clusters: quantum chemical research of isomeric composition and physical properties. Struct Chem 2019. [DOI: 10.1007/s11224-019-01417-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Döntgen M, Schmalz F, Kopp WA, Kröger LC, Leonhard K. Automated Chemical Kinetic Modeling via Hybrid Reactive Molecular Dynamics and Quantum Chemistry Simulations. J Chem Inf Model 2018; 58:1343-1355. [PMID: 29898359 DOI: 10.1021/acs.jcim.8b00078] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An automated scheme for obtaining chemical kinetic models from scratch using reactive molecular dynamics and quantum chemistry simulations is presented. This methodology combines the phase space sampling of reactive molecular dynamics with the thermochemistry and kinetics prediction capabilities of quantum mechanics. This scheme provides the NASA polynomial and modified Arrhenius equation parameters for all species and reactions that are observed during the simulation and supplies them in the ChemKin format. The ab initio level of theory for predictions is easily exchangeable, and the presently used G3MP2 level of theory is found to reliably reproduce hydrogen and methane oxidation thermochemistry and kinetics data. Chemical kinetic models obtained with this approach are ready to use for, e.g., ignition delay time simulations, as shown for hydrogen combustion. The presented extension of the ChemTraYzer approach can be used as a basis for methodological advancement of chemical kinetic modeling schemes and as a black-box approach to generate chemical kinetic models.
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Affiliation(s)
- Malte Döntgen
- Chair of Technical Thermodynamics , RWTH Aachen University , 52062 Aachen , Germany.,Molecular Science, Department of Chemistry , University of Helsinki , 00560 Helsinki , Finland
| | - Felix Schmalz
- Chair of Technical Thermodynamics , RWTH Aachen University , 52062 Aachen , Germany
| | - Wassja A Kopp
- Chair of Technical Thermodynamics , RWTH Aachen University , 52062 Aachen , Germany
| | - Leif C Kröger
- Chair of Technical Thermodynamics , RWTH Aachen University , 52062 Aachen , Germany
| | - Kai Leonhard
- Chair of Technical Thermodynamics , RWTH Aachen University , 52062 Aachen , Germany
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10
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Bao JL, Zhang X, Truhlar DG. Predicting pressure-dependent unimolecular rate constants using variational transition state theory with multidimensional tunneling combined with system-specific quantum RRK theory: a definitive test for fluoroform dissociation. Phys Chem Chem Phys 2018; 18:16659-70. [PMID: 27273734 DOI: 10.1039/c6cp02765b] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Understanding the falloff in rate constants of gas-phase unimolecular reaction rate constants as the pressure is lowered is a fundamental problem in chemical kinetics, with practical importance for combustion, atmospheric chemistry, and essentially all gas-phase reaction mechanisms. In the present work, we use our recently developed system-specific quantum RRK theory, calibrated by canonical variational transition state theory with small-curvature tunneling, combined with the Lindemann-Hinshelwood mechanism, to model the dissociation reaction of fluoroform (CHF3), which provides a definitive test for falloff modeling. Our predicted pressure-dependent thermal rate constants are in excellent agreement with experimental values over a wide range of pressures and temperatures. The present validation of our methodology, which is able to include variational transition state effects, multidimensional tunneling based on the directly calculated potential energy surface along the tunneling path, and torsional and other vibrational anharmonicity, together with state-of-the-art reaction-path-based direct dynamics calculations, is important because the method is less empirical than models routinely used for generating full mechanisms, while also being simpler in key respects than full master equation treatments and the full reduced falloff curve and modified strong collision methods of Troe.
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Affiliation(s)
- Junwei Lucas Bao
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
| | - Xin Zhang
- State Key Laboratory of Chemical Resource Engineering, Institute of Materia Medica, College of Science, Beijing University of Chemical Technology, Beijing, 100029, P. R. China. and Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
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11
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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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12
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Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice-Ramsperger-Kassel theory. Proc Natl Acad Sci U S A 2016; 113:13606-13611. [PMID: 27834727 DOI: 10.1073/pnas.1616208113] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bond dissociation is a fundamental chemical reaction, and the first principles modeling of the kinetics of dissociation reactions with a monotonically increasing potential energy along the dissociation coordinate presents a challenge not only for modern electronic structure methods but also for kinetics theory. In this work, we use multifaceted variable-reaction-coordinate variational transition-state theory (VRC-VTST) to compute the high-pressure limit dissociation rate constant of tetrafluoroethylene (C2F4), in which the potential energies are computed by direct dynamics with the M08-HX exchange correlation functional. To treat the pressure dependence of the unimolecular rate constants, we use the recently developed system-specific quantum Rice-Ramsperger-Kassel theory. The calculations are carried out by direct dynamics using an exchange correlation functional validated against calculations that go beyond coupled-cluster theory with single, double, and triple excitations. Our computed dissociation rate constants agree well with the recent experimental measurements.
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13
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Ratkiewicz A, Huynh LK, Truong TN. Performance of First-Principles-Based Reaction Class Transition State Theory. J Phys Chem B 2016; 120:1871-84. [PMID: 26752508 DOI: 10.1021/acs.jpcb.5b09564] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Performance of the Reaction Class Transition State Theory (RC-TST) for prediction of rates constants of elementary reactions is examined using data from its previous applications to a number of different reaction classes. The RC-TST theory is taking advantage of the common structure denominator of all reactions in a given family combined with structure activity relationships to provide a rigorous theoretical framework to obtain rate expression of any reaction within a reaction class in a simple and cost-effective manner. This opens the possibility for integrating this methodology with an automated mechanism generator for "on-the-fly" generation of accurate kinetic models of complex reacting systems.
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Affiliation(s)
- Artur Ratkiewicz
- Chemistry Institute, University of Bialystok , Ciolkowskiego 1K 15-245 Bialystok, Poland
| | - Lam K Huynh
- Institute for Computational Science and Technology at Ho Chi Minh City , Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam.,International University, VNU-HCMC , Thu Duc District, Ho Chi Minh City, Vietnam
| | - Thanh N Truong
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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Bao JL, Truhlar DG. Silane-initiated nucleation in chemically active plasmas: validation of density functionals, mechanisms, and pressure-dependent variational transition state calculations. Phys Chem Chem Phys 2016; 18:10097-108. [DOI: 10.1039/c6cp00816j] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pressure-dependent rate constants for nucleation in nanodusty plasmas are calculated by variational transition state theory with system-specific quantum RRK theory.
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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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15
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Rawadieh S, Altarawneh I, Alateyat HB, Altarawneh M. Theoretical study on the unimolecular decomposition of proline. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.05.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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16
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Jalan A, Alecu IM, Meana-Pañeda R, Aguilera-Iparraguirre J, Yang KR, Merchant SS, Truhlar DG, Green WH. New pathways for formation of acids and carbonyl products in low-temperature oxidation: the Korcek decomposition of γ-ketohydroperoxides. J Am Chem Soc 2013; 135:11100-14. [PMID: 23862563 DOI: 10.1021/ja4034439] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present new reaction pathways relevant to low-temperature oxidation in gaseous and condensed phases. The new pathways originate from γ-ketohydroperoxides (KHP), which are well-known products in low-temperature oxidation and are assumed to react only via homolytic O-O dissociation in existing kinetic models. Our ab initio calculations identify new exothermic reactions of KHP forming a cyclic peroxide isomer, which decomposes via novel concerted reactions into carbonyl and carboxylic acid products. Geometries and frequencies of all stationary points are obtained using the M06-2X/MG3S DFT model chemistry, and energies are refined using RCCSD(T)-F12a/cc-pVTZ-F12 single-point calculations. Thermal rate coefficients are computed using variational transition-state theory (VTST) calculations with multidimensional tunneling contributions based on small-curvature tunneling (SCT). These are combined with multistructural partition functions (Q(MS-T)) to obtain direct dynamics multipath (MP-VTST/SCT) gas-phase rate coefficients. For comparison with liquid-phase measurements, solvent effects are included using continuum dielectric solvation models. The predicted rate coefficients are found to be in excellent agreement with experiment when due consideration is made for acid-catalyzed isomerization. This work provides theoretical confirmation of the 30-year-old hypothesis of Korcek and co-workers that KHPs are precursors to carboxylic acid formation, resolving an open problem in the kinetics of liquid-phase autoxidation. The significance of the new pathways in atmospheric chemistry, low-temperature combustion, and oxidation of biological lipids are discussed.
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Affiliation(s)
- Amrit Jalan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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