1
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Hanamirian B, Della Libera A, Pratali Maffei L, Cavallotti C. Investigation of Methylcyclopentadiene Reactivity: Abstraction Reactions and Methylcyclopentadienyl Radical Unimolecular Decomposition. J Phys Chem A 2023; 127:1314-1328. [PMID: 36723173 DOI: 10.1021/acs.jpca.2c08028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Understanding the reactivities of methylcyclopentadiene and the methylcyclopentadienyl radical is important in order to improve our comprehension of the chemical kinetics leading to the formation, decomposition, and growth of the first aromatic ring, as it has been shown that five-membered-ring species are important intermediates in the reaction kinetics of aromatic species. In this work, the rate constants of some key H-abstraction reactions from methylcyclopentadiene to produce the methylcyclopentadienyl radical and the formation of fulvene and benzene from the latter are theoretically determined. Rate constants are evaluated using the ab initio transition state theory-based master equation approach, determining structures and Hessians of all stationary points at the ωB97X-D/aug-cc-pVTZ level, energies at the CCSD(T) level extrapolated to the complete basis set limit, RRKM rate constants using conventional and variational transition state theory, and phenomenological rate constants through the solution of the one-dimensional master equation. Variational corrections are determined in both internal and Cartesian coordinates, and it is found that the choice of the coordinate system can impact the accuracy of the calculated rate constants by up to a factor of 4 for H-abstraction reactions and 2 for the unimolecular decomposition of the methylcyclopentadienyl radical. The calculated rate constants are in good agreement with the available literature data. Prompt dissociation of methylcyclopentadienyl radicals accessed following H-abstraction from methylcyclopentadiene was also investigated, and the corresponding rate constants were determined; the results show that prompt dissociation plays a key role under combustion conditions. Finally, lumping of theoretically derived rate constants to account for methylcyclopentadiene ⇄ methylcyclopentadienyl tautomerism allowed the derivation of a simplified set of rate constants suitable to be inserted into kinetic mechanisms.
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Affiliation(s)
- Burak Hanamirian
- Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20131Milano, Italy
| | - Andrea Della Libera
- Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20131Milano, Italy
| | - Luna Pratali Maffei
- Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20131Milano, Italy
| | - Carlo Cavallotti
- Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20131Milano, Italy
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2
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Raj A, Thiraviam P, Elkadi M. A Reaction Kinetics Study on Benzene Oxidation in the Claus Process by Sulfur Monoxide. J Phys Chem A 2023; 127:1013-1025. [PMID: 36669093 DOI: 10.1021/acs.jpca.2c06586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The Claus process is used in natural gas processing plants to treat H2S-rich acid gas to recover sulfur, but the process suffers from catalytic deactivation when aromatic contaminants such as benzene, toluene, ethylbenzene, and xylene isomers (collectively called as BTEX) are present in the acid gas feed. To safeguard the catalytic reactors, it is desired to oxidize aromatic contaminants in the furnace that are present upstream of the catalytic reactors in the process by oxidants present in it. This work develops a reaction mechanism and evaluates the reaction kinetics for the oxidation of phenyl radical by SO using CBS-QBS for reaction energetics and RRKM and transition state theory for reaction kinetics. The mechanism explores the possible products that are formed from the barrierless addition of SO on phenyl through the O atom as well as through the S atom. The exothermicity of the addition reaction is higher when the addition of SO on the aromatic structure takes place through the S atom. The major products formed from phenyl oxidation by SO are cyclopentadienyl, cyclopentadienethiol and thiopyran radicals. A remarkable similarity between the pathways for phenyl radical oxidation by O2 and its oxidation by SO at high temperatures is observed. The proposed reactions and their rate constants are used to conduct reactor simulations to determine the important reactions that contribute to the formation of major products during phenyl-SO reactions and the temperatures suitable for benzene oxidation by SO under process conditions similar to the Claus furnace.
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Affiliation(s)
- Abhijeet Raj
- Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi110016, India
| | - Preethika Thiraviam
- Department of Chemistry, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE.,Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, Dubai Campus, P.O. Box 345055, Dubai, UAE
| | - Mirella Elkadi
- Department of Chemistry, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
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3
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Schmitz G, Yönder Ö, Schnieder B, Schmid R, Hättig C. An automatized workflow from molecular dynamic simulation to quantum chemical methods to identify elementary reactions and compute reaction constants. J Comput Chem 2021; 42:2264-2282. [PMID: 34636424 DOI: 10.1002/jcc.26757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present an automatized workflow which, starting from molecular dynamics simulations, identifies reaction events, filters them, and prepares them for accurate quantum chemical calculations using, for example, Density Functional Theory (DFT) or Coupled Cluster methods. The capabilities of the automatized workflow are demonstrated by the example of simulations for the combustion of some polycyclic aromatic hydrocarbons (PAHs). It is shown how key elementary reaction candidates are filtered out of a much larger set of redundant reactions and refined further. The molecular species in question are optimized using DFT and reaction energies, barrier heights, and reaction rates are calculated. The setup is general enough to include at this stage configurational sampling, which can be exploited in the future. Using the introduced machinery, we investigate how the observed reaction types depend on the gas atmosphere used in the molecular dynamics simulation. For the re-optimization on the DFT level, we show how the additional information needed to switch from reactive force-field to electronic structure calculations can be filled in and study how well ReaxFF and DFT agree with each other and shine light on the perspective of using more accurate semi-empirical methods in the MD simulation.
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Affiliation(s)
- Gunnar Schmitz
- Computational Materials Chemistry Group, Ruhr-Universität Bochum, Bochum, Germany
| | - Özlem Yönder
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, Bochum, Germany
| | - Bastian Schnieder
- Computational Materials Chemistry Group, Ruhr-Universität Bochum, Bochum, Germany
| | - Rochus Schmid
- Computational Materials Chemistry Group, Ruhr-Universität Bochum, Bochum, Germany
| | - Christof Hättig
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, Bochum, Germany
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4
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Lopes Jesus AJ, Fausto R, Reva I. Conformational Space, IR-Induced, and UV-Induced Chemistry of Carvacrol Isolated in a Low-Temperature Argon Matrix. J Phys Chem A 2021; 125:8215-8229. [PMID: 34506137 DOI: 10.1021/acs.jpca.1c05907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In this work, monomers of carvacrol (5-isopropyl-2-methylphenol), a natural monoterpene exhibiting wide range bioactivity, were trapped in a cryogenic argon matrix and characterized by infrared spectroscopy, while quantum chemical calculations at the B3LYP and MP2 levels were employed to characterize the conformational landscape of the isolated molecule. Four conformers have been localized on the potential energy surface, and the factors accounting for their relative stability were analyzed. The two most stable conformers of carvacrol, differing in the relative orientation of the isopropyl group and both having the OH group pointing away from the vicinal methyl fragment, were identified in the cryomatrix for the first time. The individual spectral signatures of the two conformers were distinguished based on the change in their relative abundance induced by exposing the matrix to broadband infrared light. Matrix-isolated carvacrol was also irradiated with broadband UV light (λ > 200 nm), which resulted in the cleavage of the OH group. Recombination of the released H atom at the ortho- or para-position of the ring resulted in the formation of alkyl-substituted cyclohexadienones. These were found to undergo subsequent valence and open-ring isomerizations, leading, respectively, to the formation of a Dewar isomer and open-chain conjugated ketenes. Decarbonylation of the photoproducts was also observed for longer irradiation times. A mechanistic analysis of the observed photochemical transformations is presented.
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Affiliation(s)
- A J Lopes Jesus
- University of Coimbra, CQC, Faculty of Pharmacy, 3004-295 Coimbra, Portugal
| | - Rui Fausto
- University of Coimbra, CQC, Department of Chemistry, 3004-535 Coimbra, Portugal
| | - Igor Reva
- University of Coimbra, CQC, Department of Chemistry, 3004-535 Coimbra, Portugal.,University of Coimbra, CIEPQPF, Department of Chemical Engineering, 3030-790 Coimbra, Portugal
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5
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Pratali Maffei L, Pelucchi M, Faravelli T, Cavallotti C. Theoretical study of sensitive reactions in phenol decomposition. REACT CHEM ENG 2020. [DOI: 10.1039/c9re00418a] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity of phenol is of utmost importance in combustion systems.
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Affiliation(s)
- Luna Pratali Maffei
- CRECK Modeling Lab
- Department of Chemistry, Materials, and Chemical Engineering
- Politecnico di Milano
- Italy
| | - Matteo Pelucchi
- CRECK Modeling Lab
- Department of Chemistry, Materials, and Chemical Engineering
- Politecnico di Milano
- Italy
| | - Tiziano Faravelli
- CRECK Modeling Lab
- Department of Chemistry, Materials, and Chemical Engineering
- Politecnico di Milano
- Italy
| | - Carlo Cavallotti
- CRECK Modeling Lab
- Department of Chemistry, Materials, and Chemical Engineering
- Politecnico di Milano
- Italy
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6
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Wang H, Wen K, You X, Mao Q, Luo KH, Pilling MJ, Robertson SH. Energy transfer in intermolecular collisions of polycyclic aromatic hydrocarbons with bath gases He and Ar. J Chem Phys 2019; 151:044301. [PMID: 31370521 DOI: 10.1063/1.5094104] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Classical trajectory simulations of intermolecular collisions were performed for a series of polycyclic aromatic hydrocarbons interacting with the bath gases helium and argon for bath gas temperature from 300 to 2500 K. The phase-space average energy transferred per deactivating collision, ⟨∆Edown⟩, was obtained. The Buckingham pairwise intermolecular potentials were validated against high-level quantum chemistry calculations and used in the simulations. The reactive force-field was used to describe intramolecular potentials. The dependence of ⟨∆Edown⟩ on initial vibrational energy is discussed. A canonical sampling method was compared with a microcanonical sampling method for selecting initial vibrational energy at high bath gas temperatures. Uncertainties introduced by the initial angular momentum distribution were identified. The dependence of the collisional energy transfer parameters on the type of bath gas and the molecular structure of polycyclic aromatic hydrocarbons was examined.
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Affiliation(s)
- Hongmiao Wang
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
| | - Kaicheng Wen
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
| | - Xiaoqing You
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
| | - Qian Mao
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
| | - Kai Hong Luo
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Michael J Pilling
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Struan H Robertson
- Dassault Systèmes, BIOVIA, 334, Cambridge Science Park, Cambridge CB4 0WN, United Kingdom
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7
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Nowakowska M, Herbinet O, Dufour A, Glaude PA. Kinetic Study of the Pyrolysis and Oxidation of Guaiacol. J Phys Chem A 2018; 122:7894-7909. [DOI: 10.1021/acs.jpca.8b06301] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Nowakowska
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, 1 rue Grandville BP 20451, Nancy 54001 Cedex, France
| | - O. Herbinet
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, 1 rue Grandville BP 20451, Nancy 54001 Cedex, France
| | - A. Dufour
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, 1 rue Grandville BP 20451, Nancy 54001 Cedex, France
| | - P. A. Glaude
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, 1 rue Grandville BP 20451, Nancy 54001 Cedex, France
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8
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Furutani Y, Dohara Y, Kudo S, Hayashi JI, Norinaga K. Computational Study on the Thermal Decomposition of Phenol-Type Monolignols. INT J CHEM KINET 2018. [DOI: 10.1002/kin.21164] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yuki Furutani
- Interdisciplinary Graduate School of Engineering Sciences; Kyushu University; Kasuga Fukuoka 816-8580 Japan
| | - Yuki Dohara
- Interdisciplinary Graduate School of Engineering Sciences; Kyushu University; Kasuga Fukuoka 816-8580 Japan
| | - Shinji Kudo
- Institute for Materials Chemistry and Engineering; Kyushu University; Kasuga Fukuoka 816-8580 Japan
| | - Jun-Ichiro Hayashi
- Institute for Materials Chemistry and Engineering; Kyushu University; Kasuga Fukuoka 816-8580 Japan
- Research and Education Centre of Carbon Resources; Kyushu University; Kasuga Fukuoka 816-8580 Japan
| | - Koyo Norinaga
- Department of Chemical Systems Engineering; Graduate School of Engineering; Nagoya University; Nagoya 464-8603 Japan
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9
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Furutani Y, Dohara Y, Kudo S, Hayashi JI, Norinaga K. Theoretical Study on Elementary Reaction Steps in Thermal Decomposition Processes of Syringol-Type Monolignol Compounds. J Phys Chem A 2018; 122:822-831. [PMID: 29236494 DOI: 10.1021/acs.jpca.7b09450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper theoretically investigated a large number of reaction pathways and kinetics to describe the vapor-phase pyrolytic behavior of several syringol-type monolignol compounds that are derived from the primary pyrolysis of lignin: 1-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-en-1-one (HDPP), sinapyl alcohol, 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)propan-1-one (HHDPP), 1-(4-hydroxy-3,5-dimethoxyphenyl)propane-1,3-diol (HDPPD), and syringol. The possible pyrolytic pathways involving unimolecular decomposition, addition, and abstraction reactions were investigated by comparing the energy barriers calculated at the B3LYP/6-311++G(d,p) level. In the proposed pathways, all syringol-type monolignols containing a side chain undergo its cleavage to form syringol through the formation of syringaldehyde or 4-vinylsyringol. Syringol is then converted into two products: (a) pyrogallol via the homolysis of the O-CH3 bond and hydrogenation or (b) guaiacol via addition of an H atom with a carbon bearing methoxyl group in syrignol and the subsequent demethoxylation. The pyrolytic pathways of pyrogallol are classified into two processes: (a) the concerted dehydrogenation of the two hydroxyl H atoms and the unimolecular decomposition to produce acetylene (C2H2), ethynol (C2HOH), and CO or (b) the displacement of an OH with H to produce catechol and resorcinol. Additionally, HDPP undergoes O-CH3 bond cleavage to form but-1-en-3-yne. The high-pressure limit rate constants for all the proposed elementary reaction steps were evaluated on the basis of transition state theory.
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Affiliation(s)
| | | | | | | | - Koyo Norinaga
- Department of Chemical Systems Engineering, Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan
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10
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Furutani Y, Dohara Y, Kudo S, Hayashi JI, Norinaga K. Theoretical Study on the Kinetics of Thermal Decomposition of Guaiacol and Catechol. J Phys Chem A 2017; 121:8495-8503. [DOI: 10.1021/acs.jpca.7b08112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - Koyo Norinaga
- Department
of Chemical Systems Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan
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11
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Shu B, Herzler J, Peukert S, Fikri M, Schulz C. A Shock Tube and Modeling Study about Anisole Pyrolysis Using Time-Resolved CO Absorption Measurements. INT J CHEM KINET 2017. [DOI: 10.1002/kin.21105] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Bo Shu
- IVG, Institute for Combustion and Gas Dynamics - Reactive Fluids; University of Duisburg-Essen; 47048 Duisburg Germany
| | - Jürgen Herzler
- IVG, Institute for Combustion and Gas Dynamics - Reactive Fluids; University of Duisburg-Essen; 47048 Duisburg Germany
| | - Sebastian Peukert
- IVG, Institute for Combustion and Gas Dynamics - Reactive Fluids; University of Duisburg-Essen; 47048 Duisburg Germany
| | - Mustapha Fikri
- IVG, Institute for Combustion and Gas Dynamics - Reactive Fluids; University of Duisburg-Essen; 47048 Duisburg Germany
| | - Christof Schulz
- IVG, Institute for Combustion and Gas Dynamics - Reactive Fluids; University of Duisburg-Essen; 47048 Duisburg Germany
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12
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Furutani Y, Kudo S, Hayashi JI, Norinaga K. Theoretical Study on Reaction Pathways Leading to CO and CO2 in the Pyrolysis of Resorcinol. J Phys Chem A 2017; 121:631-637. [DOI: 10.1021/acs.jpca.6b05168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuki Furutani
- Interdisciplinary
Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
| | - Shinji Kudo
- Interdisciplinary
Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
- Institute
for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580, Japan
| | - Jun-ichiro Hayashi
- Interdisciplinary
Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
- Institute
for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580, Japan
- Research
and Education Centre of Carbon Resources, Kyushu University, Kasuga 816-8580, Japan
| | - Koyo Norinaga
- Interdisciplinary
Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
- Institute
for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580, Japan
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13
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Wang K, Villano SM, Dean AM. Ab initio study of the influence of resonance stabilization on intramolecular ring closure reactions of hydrocarbon radicals. Phys Chem Chem Phys 2016; 18:8437-52. [DOI: 10.1039/c5cp06994g] [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
The cyclization reactions of dieneyl radicals provide a low energy route to the formation of molecular weight growth products.
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Affiliation(s)
- Kun Wang
- Chemical and Biological Engineering Dept
- Colorado School of Mines
- Golden
- USA
| | | | - Anthony M. Dean
- Chemical and Biological Engineering Dept
- Colorado School of Mines
- Golden
- USA
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14
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Wang K, Villano SM, Dean AM. Reactions of allylic radicals that impact molecular weight growth kinetics. Phys Chem Chem Phys 2015; 17:6255-73. [DOI: 10.1039/c4cp05308g] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of allylic radicals have the potential to play a critical role in molecular weight growth (MWG) kinetics during hydrocarbon oxidation and/or pyrolysis.
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Affiliation(s)
- Kun Wang
- Chemical and Biological Engineering Department
- Colorado School of Mines
- Golden
- USA
| | | | - Anthony M. Dean
- Chemical and Biological Engineering Department
- Colorado School of Mines
- Golden
- USA
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15
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Robichaud DJ, Scheer AM, Mukarakate C, Ormond TK, Buckingham GT, Ellison GB, Nimlos MR. Unimolecular thermal decomposition of dimethoxybenzenes. J Chem Phys 2014; 140:234302. [DOI: 10.1063/1.4879615] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Harrison AW, Lim JS, Ryazanov M, Wang G, Gao S, Neumark DM. Photodissociation dynamics of the thiophenoxy radical at 248, 193, and 157 nm. J Phys Chem A 2013; 117:11970-8. [PMID: 23822615 DOI: 10.1021/jp403229h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The photodissociation dynamics of the thiophenoxy radical (C6H5S) have been investigated using fast beam coincidence translational spectroscopy. Thiophenoxy radicals were produced by photodetachment of the thiophenoxide anion followed by photodissociation at 248 nm (5.0 eV), 193 nm (6.4 eV), and 157 nm (7.9 eV). Experimental results indicate two major competing dissociation channels leading to SH + C6H4 (o-benzyne) and CS + C5H5 (cyclopentadienyl) with a minor contribution of S + C6H5 (phenyl). Photofragment mass distributions and translational energy distributions were measured at each dissociation wavelength. Transition states and minima for each reaction pathway were calculated using density functional theory to facilitate experimental interpretation. The proposed dissociation mechanism involves internal conversion from the initially prepared electronic excited state to the ground electronic state followed by statistical dissociation. Calculations show that SH loss involves a single isomerization step followed by simple bond fission. For both SH and S loss, C-S bond cleavage proceeds without an exit barrier. By contrast, the CS loss pathway entails multiple transition states and minima as it undergoes five membered ring formation and presents a small barrier with respect to products. The calculated reaction pathway is consistent with the experimental translational energy distributions in which the CS loss channel has a broader distribution peaking farther away from zero than the corresponding distributions for SH loss.
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Affiliation(s)
- Aaron W Harrison
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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17
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Xu H, Pratt ST. Photodissociation of Anisole and Absolute Photoionization Cross-Section of the Phenoxy Radical. J Phys Chem A 2013; 117:12075-81. [DOI: 10.1021/jp4047177] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hong Xu
- Argonne National Laboratory,
Argonne, Illinois 60439, United States
| | - S. T. Pratt
- Argonne National Laboratory,
Argonne, Illinois 60439, United States
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18
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Villano SM, Carstensen HH, Dean AM. Rate Rules, Branching Ratios, and Pressure Dependence of the HO2 + Olefin Addition Channels. J Phys Chem A 2013; 117:6458-73. [DOI: 10.1021/jp405262r] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephanie M. Villano
- Chemical
and Biological Engineering Department, Colorado
School of Mines, Golden Colorado 80301, United States
| | - Hans-Heinrich Carstensen
- Chemical
and Biological Engineering Department, Colorado
School of Mines, Golden Colorado 80301, United States
| | - Anthony M. Dean
- Chemical
and Biological Engineering Department, Colorado
School of Mines, Golden Colorado 80301, United States
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19
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Villano SM, Huynh LK, Carstensen HH, Dean AM. High-Pressure Rate Rules for Alkyl + O2 Reactions. 2. The Isomerization, Cyclic Ether Formation, and β-Scission Reactions of Hydroperoxy Alkyl Radicals. J Phys Chem A 2012; 116:5068-89. [DOI: 10.1021/jp3023887] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephanie M. Villano
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80301, United
States
| | - Lam K. Huynh
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80301, United
States
| | - Hans-Heinrich Carstensen
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80301, United
States
| | - Anthony M. Dean
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80301, United
States
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