1
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Levey ZD, Laws BA, Sundar SP, Nauta K, Kable SH, da Silva G, Stanton JF, Schmidt TW. PAH Growth in Flames and Space: Formation of the Phenalenyl Radical. J Phys Chem A 2021; 126:101-108. [PMID: 34936357 DOI: 10.1021/acs.jpca.1c08310] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are intermediates in the formation of soot particles and interstellar grains. However, their formation mechanisms in combustion and interstellar environments are not fully understood. The production of tricyclic PAHs and, in particular, the conversion of a PAH containing a five-membered ring to one with a six-membered ring are of interest to explain PAH abundances in combustion processes. In the present work, resonant ionization mass spectrometry in conjunction with isotopic labeling is used to investigate the formation of the phenalenyl radical from acenaphthylene and methane in an electrical discharge. We show that in this environment the CH cycloaddition mechanism converts a five-membered ring to a six-membered ring. This mechanism can occur in tandem with other PAH formation mechanisms such as hydrogen abstraction/acetylene addition (HACA) to produce larger PAHs in flames and the interstellar medium.
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Affiliation(s)
- Zachariah D Levey
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Benjamin A Laws
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Srivathsan P Sundar
- Department of Chemical Engineering, The University of Melbourne, Parkville 3010, Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Scott H Kable
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Gabriel da Silva
- Department of Chemical Engineering, The University of Melbourne, Parkville 3010, Australia
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Timothy W Schmidt
- Centre of Excellence in Exciton Science, University of New South Wales, Sydney, NSW 2052, Australia
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2
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Bourgalais J, Carrasco N, Vettier L, Comby A, Descamps D, Petit S, Blanchet V, Gaudin J, Mairesse Y, Marty B. Aromatic Formation Promoted by Ion-Driven Radical Pathways in EUV Photochemical Experiments Simulating Titan's Atmospheric Chemistry. J Phys Chem A 2021; 125:3159-3168. [PMID: 33843236 DOI: 10.1021/acs.jpca.1c00324] [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
In the atmosphere of Titan, Saturn's main satellite, molecular growth is initiated by 85.6 nm extreme ultraviolet (EUV) photons triggering a chemistry with charged and free-radical species. However, the respective contribution of these species to the complexification of matter is far from being known. This work presents a chemical analysis in order to contribute to a better understanding of aromatic formation pathways. A gas mixture of N2/CH4 (90/10%) within the closed SURFACAT reactor was irradiated at a relatively low pressure (0.1 mbar) and room temperature for 6 h by EUV photons (∼85.6 nm). The neutral molecules formed at the end of the irradiation were condensed in a cryogenic trap and analyzed by electron ionization mass spectrometry. An analysis of the dominant chemical pathways highlights the identification of benzene and toluene and underlies the importance of small ion and radical reactions. On the basis of the experimental results, a speculative mechanism based on sequential H-elimination/CH3-addition reactions is proposed for the growth of aromatics in Titan's atmosphere. Elementary reactions to be studied are given to instill future updates of photochemical models of Titan's atmosphere.
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Affiliation(s)
- Jérémy Bourgalais
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France.,Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS-Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, F-54501 Vandoeuvre-lès-Nancy, France
| | - Nathalie Carrasco
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France
| | - Ludovic Vettier
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France
| | - Antoine Comby
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Dominique Descamps
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Stéphane Petit
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Valérie Blanchet
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Jérôme Gaudin
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Yann Mairesse
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Bernard Marty
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS - Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, F-54501 Vandoeuvre-lès-Nancy, France
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3
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He C, Thomas AM, Galimova GR, Mebel AM, Kaiser RI. Gas-Phase Formation of 1-Methylcyclopropene and 3-Methylcyclopropene via the Reaction of the Methylidyne Radical (CH; X 2Π) with Propylene (CH 3CHCH 2; X 1A'). J Phys Chem A 2019; 123:10543-10555. [PMID: 31718184 DOI: 10.1021/acs.jpca.9b09815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The crossed molecular beam reactions of the methylidyne radical (CH; X2Π) with propylene (CH3CHCH2; X1A') along with (partially) substituted reactants were conducted at collision energies of 19.3 kJ mol-1. Combining our experimental data with ab initio electronic structure and statistical calculations, the methylidyne radical is revealed to add barrierlessly to the carbon-carbon double bond of propylene reactant resulting in a cyclic doublet C4H7 intermediate with a lifetime longer than its rotation period. These adducts undergo a nonstatistical unimolecular decomposition via atomic hydrogen loss through tight exit transition states forming the cyclic products 1-methylcyclopropene and 3-methylcyclopropene with overall reaction exoergicities of 168 ± 25 kJ mol-1. These C4H6 isomers are predicted to exist even in low-temperature environments such as cold molecular clouds like TMC-1, since the reaction is barrierless and exoergic, all transition states are below the energy of the separated reactants, and both the methylidyne radical (CH; X2Π) and propylene reactant were detected in cold molecular clouds such as TMC-1.
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Affiliation(s)
- Chao He
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
| | - Aaron M Thomas
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
| | - Galiya R Galimova
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States.,Samara National Research University , Samara 443086 , Russia
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States
| | - Ralf I Kaiser
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
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4
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Caster KL, Donnellan ZN, Selby TM, Goulay F. Kinetic Investigations of the CH (X2Π) Radical Reaction with Cyclopentadiene. J Phys Chem A 2019; 123:5692-5703. [PMID: 31194547 DOI: 10.1021/acs.jpca.9b03813] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kacee L. Caster
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Zachery N. Donnellan
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Talitha M. Selby
- Department of Mathematics and Natural Sciences, University of Wisconsin—Milwaukee, West Bend, Wisconsin 53095, United States
| | - F. Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
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5
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Abplanalp MJ, Góbi S, Kaiser RI. On the formation and the isomer specific detection of methylacetylene (CH 3CCH), propene (CH 3CHCH 2), cyclopropane (c-C 3H 6), vinylacetylene (CH 2CHCCH), and 1,3-butadiene (CH 2CHCHCH 2) from interstellar methane ice analogues. Phys Chem Chem Phys 2019; 21:5378-5393. [PMID: 30221272 DOI: 10.1039/c8cp03921f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pure methane (CH4) ices processed by energetic electrons under ultra-high vacuum conditions to simulate secondary electrons formed via galactic cosmic rays (GCRs) penetrating interstellar ice mantles have been shown to produce an array of complex hydrocarbons with the general formulae: CnH2n+2 (n = 4-8), CnH2n (n = 3-9), CnH2n-2 (n = 3-9), CnH2n-4 (n = 4-9), and CnH2n-6 (n = 6-7). By monitoring the in situ chemical evolution of the ice combined with temperature programmed desorption (TPD) studies and tunable single photon ionization coupled to a reflectron time-of-flight mass spectrometer, specific isomers of C3H4, C3H6, C4H4, and C4H6 were probed. These experiments confirmed the synthesis of methylacetylene (CH3CCH), propene (CH3CHCH2), cyclopropane (c-C3H6), vinylacetylene (CH2CHCCH), 1-butyne (HCCC2H5), 2-butyne (CH3CCCH3), 1,2-butadiene (H2CCCH(CH3)), and 1,3-butadiene (CH2CHCHCH2) with yields of 2.17 ± 0.95 × 10-4, 3.7 ± 1.5 × 10-3, 1.23 ± 0.77 × 10-4, 1.28 ± 0.65 × 10-4, 4.01 ± 1.98 × 10-5, 1.97 ± 0.98 × 10-4, 1.90 ± 0.84 × 10-5, and 1.41 ± 0.72 × 10-4 molecules eV-1, respectively. Mechanistic studies exploring the formation routes of methylacetylene, propene, and vinylacetylene were also conducted, and revealed the additional formation of the 1,2,3-butatriene isomer. Several of the above isomers, methylacetylene, propene, vinylacetylene, and 1,3-butadiene, have repeatedly been shown to be important precursors in the formation of polycyclic aromatic hydrocarbons (PAHs), but until now their interstellar synthesis has remained elusive.
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Affiliation(s)
- Matthew J Abplanalp
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
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6
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Wang W, Feng W, Wang W, Li P. Theoretical Investigations on the Reactivity of Methylidyne Radical toward 2,3,7,8-Tetrachlorodibenzo- p-Dioxin: A DFT and Molecular Dynamics Study. Molecules 2018; 23:E2685. [PMID: 30340385 PMCID: PMC6222546 DOI: 10.3390/molecules23102685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/22/2022] Open
Abstract
To explore the potential reactivity of the methylidyne radical (CH) toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the reaction mechanism between them has been systematically investigated employing the density functional theory (DFT) and ab initio molecular dynamics simulations. The relevant thermodynamic and kinetic parameters in the possible reaction pathways have been discussed as well as the IR spectra and hyperfine coupling constants (hfcc's) of the major products. Different from the reaction of the CH radical with 2,3,7,8-tetrachlorodibenzofuran, CH radical can attack all the C-C bonds of TCDD to form an initial intermediate barrierlessly via the cycloaddition mechanism. After then, the introduced C-H bond can be further inserted into the C-C bond of TCDD, resulting in the formation of a seven-membered ring structure. The whole reactions are favorable thermodynamically and kinetically. Moreover, the major products have been verified by ab initio molecular dynamics simulations. The distinct IR spectra and hyperfine coupling constants of the major products can provide some help for their experimental detection and identification. In addition, the reactivity of the CH radical toward the F- and Br-substituted TCDDs has also been investigated. Hopefully, the present findings can provide new insights into the reactivity of the CH radical in the transformation of TCDD-like dioxins.
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Affiliation(s)
- Weihua Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Wenling Feng
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Wenliang Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
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7
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Carrasco E, Meloni G. Study of Methylidyne Radical (CH and CD) Reaction with 2,5-Dimethylfuran Using Multiplexed Synchrotron Photoionization Mass Spectrometry. J Phys Chem A 2018; 122:6118-6133. [DOI: 10.1021/acs.jpca.8b04140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Erica Carrasco
- Department of Chemistry, University of San Francisco, San Francisco, California 94117, United States
| | - Giovanni Meloni
- Department of Physical and Chemical Sciences, Università degli Studi de L’Aquila, L’Aquila, Italy
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8
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Wei W, Wang W, Xu K, Feng W, Li X, Li P. Theoretical insights into the reaction mechanisms between 2,3,7,8-tetrachlorodibenzofuran and the methylidyne radical. RSC Adv 2018; 8:21150-21163. [PMID: 35539902 PMCID: PMC9080895 DOI: 10.1039/c8ra03046d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/03/2018] [Indexed: 11/21/2022] Open
Abstract
To explore the potential role of the methylidyne radical (CH) in the transformation of 2,3,7,8-tetrachlorodibenzofuran (TCDF), in this study, the detailed reaction mechanisms between TCDF and CH radical have been systematically investigated employing the B3LYP method of density functional theory (DFT) in combination with the atoms in molecules (AIM) theory and ab initio molecular dynamics. It was found that the title reaction is a multi-channel reaction, i.e., the CH radical can attack the C-X (X = C, Cl, H, O) bonds of TCDF via the insertion modes, resulting in the formation of 13 products. Thermodynamically, the whole reaction processes are exothermic and spontaneous since all the enthalpy and Gibbs free energy changes are negative values in the formation processes. Moreover, the thermodynamic stability of the products is controlled by the distribution of the single unpaired electron. Kinetically, the most favorable reaction channel is the insertion of the CH radical into the C-C bond except for the C atoms attached to the chlorine atom. Moreover, the dominant products have been further confirmed by the molecular dynamics. Meanwhile, the IR spectra and hyperfine coupling constants of the dominant products have been investigated to provide helpful information for their identification experimentally. In addition, the reactivity of the CH radical toward the F- and Br-substituted TCDFs has also been investigated. Expectedly, the present findings can enable us to better understand the reactivity of the CH radical toward organic pollutants analogous to TCDF in the atmosphere.
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Affiliation(s)
- Wenjing Wei
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Weihua Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Kaining Xu
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Wenling Feng
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Xiaoping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
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9
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Carrasco E, Smith KJ, Meloni G. Synchrotron Photoionization Study of Furan and 2-Methylfuran Reactions with Methylidyne Radical (CH) at 298 K. J Phys Chem A 2017; 122:280-291. [DOI: 10.1021/acs.jpca.7b10382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Erica Carrasco
- Department of Chemistry, University of San Francisco, San
Francisco, California 94117, United States
| | - Kenneth J. Smith
- Department of Chemistry, University of San Francisco, San
Francisco, California 94117, United States
| | - Giovanni Meloni
- Department of Chemistry, University of San Francisco, San
Francisco, California 94117, United States
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10
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Pakhira S, Singh RI, Olatunji-Ojo O, Frenklach M, Lester WA. Quantum Monte Carlo Study of the Reactions of CH with Acrolein: Major and Minor Channels. J Phys Chem A 2016; 120:3602-12. [DOI: 10.1021/acs.jpca.5b11527] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Srimanta Pakhira
- Chemical Sciences Division (CSD) and ⊥Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kenneth S. Pitzer Center for Theoretical Chemistry,
Department of
Chemistry, §Department of Mechanical Engineering, and ∥College of Chemistry, University of California, Berkeley, California 94720, United States
| | - Ravi I. Singh
- Chemical Sciences Division (CSD) and ⊥Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kenneth S. Pitzer Center for Theoretical Chemistry,
Department of
Chemistry, §Department of Mechanical Engineering, and ∥College of Chemistry, University of California, Berkeley, California 94720, United States
| | - Olayinka Olatunji-Ojo
- Chemical Sciences Division (CSD) and ⊥Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kenneth S. Pitzer Center for Theoretical Chemistry,
Department of
Chemistry, §Department of Mechanical Engineering, and ∥College of Chemistry, University of California, Berkeley, California 94720, United States
| | - Michael Frenklach
- Chemical Sciences Division (CSD) and ⊥Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kenneth S. Pitzer Center for Theoretical Chemistry,
Department of
Chemistry, §Department of Mechanical Engineering, and ∥College of Chemistry, University of California, Berkeley, California 94720, United States
| | - William A. Lester
- Chemical Sciences Division (CSD) and ⊥Environmental
Energy Technologies
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kenneth S. Pitzer Center for Theoretical Chemistry,
Department of
Chemistry, §Department of Mechanical Engineering, and ∥College of Chemistry, University of California, Berkeley, California 94720, United States
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11
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Hickson KM, Wakelam V, Loison JC. Methylacetylene (CH3CCH) and propene (C3H6) formation in cold dense clouds: A case of dust grain chemistry. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molap.2016.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Ribeiro JM, Mebel AM. Reaction Mechanism and Product Branching Ratios of the CH + C3H6 Reaction: A Theoretical Study. J Phys Chem A 2016; 120:1800-12. [DOI: 10.1021/acs.jpca.5b12588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joao Marcelo Ribeiro
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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13
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Trevitt AJ, Goulay F. Insights into gas-phase reaction mechanisms of small carbon radicals using isomer-resolved product detection. Phys Chem Chem Phys 2016; 18:5867-82. [DOI: 10.1039/c5cp06389b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase radical reactions of CN and CH with small hydrocarbons are overviewed with emphasis on isomer-resolved product detection.
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Affiliation(s)
- Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
| | - Fabien Goulay
- Department of Chemistry
- West Virginia University
- Morgantown
- USA
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14
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Prozument K, Barratt Park G, Shaver RG, Vasiliou AK, Oldham JM, David DE, Muenter JS, Stanton JF, Suits AG, Barney Ellison G, Field RW. Chirped-Pulse millimeter-Wave spectroscopy for dynamics and kinetics studies of pyrolysis reactions. Phys Chem Chem Phys 2015; 16:15739-15751. [PMID: 24756159 DOI: 10.1039/c3cp55352c] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Chirped-Pulse millimeter-Wave (CPmmW) spectrometer is applied to the study of chemical reaction products that result from pyrolysis in a Chen nozzle heated to 1000-1800 K. Millimeter-wave rotational spectroscopy unambiguously determines, for each polar reaction product, the species, the conformers, relative concentrations, conversion percentage from precursor to each product, and, in some cases, vibrational state population distributions. A chirped-pulse spectrometer can, within the frequency range of a single chirp, sample spectral regions of up to ∼10 GHz and simultaneously detect many reaction products. Here we introduce a modification to the CPmmW technique in which multiple chirps of different spectral content are applied to a molecular beam pulse that contains the pyrolysis reaction products. This technique allows for controlled allocation of its sensitivity to specific molecular transitions and effectively doubles the bandwidth of the spectrometer. As an example, the pyrolysis reaction of ethyl nitrite, CH3CH2ONO, is studied, and CH3CHO, H2CO, and HNO products are simultaneously observed and quantified, exploiting the multi-chirp CPmmW technique. Rotational and vibrational temperatures of some product molecules are determined. Subsequent to supersonic expansion from the heated nozzle, acetaldehyde molecules display a rotational temperature of 4 ± 1 K. Vibrational temperatures are found to be controlled by the collisional cooling in the expansion, and to be both species- and vibrational mode-dependent. Rotational transitions of vibrationally excited formaldehyde in levels ν4, 2ν4, 3ν4, ν2, ν3, and ν6 are observed and effective vibrational temperatures for modes 2, 3, 4, and 6 are determined and discussed.
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Affiliation(s)
- Kirill Prozument
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA. and Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - G Barratt Park
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Rachel G Shaver
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - AnGayle K Vasiliou
- Department of Chemistry and Biochemistry, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753, USA
| | - James M Oldham
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - Donald E David
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Cristol Chemistry 58, Boulder, CO 80309, USA
| | - John S Muenter
- Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, NY 14627, USA
| | - John F Stanton
- Department of Chemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-0165, USA
| | - Arthur G Suits
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Cristol Chemistry 58, Boulder, CO 80309, USA
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
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15
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Pakhira S, Lengeling BS, Olatunji-Ojo O, Caffarel M, Frenklach M, Lester WA. A quantum Monte Carlo study of the reactions of CH with acrolein. J Phys Chem A 2015; 119:4214-23. [PMID: 25826390 DOI: 10.1021/acs.jpca.5b00919] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To assist understanding of combustion processes, we have investigated reactions of methylidyne (CH) with acrolein (CH2CHCHO) using the quantum Monte Carlo (QMC) and other computational methods. We present a theoretical study of the major reactions reported in a recent experiment on the subject system. Both DFT and MP2 computations are carried out, and the former approach is used to form the independent-particle part of the QMC trial wave function used in the diffusion Monte Carlo (DMC) variant of the QMC method. In agreement with experiment, we find that the dominant product channel leads to formation of C4H4O systems + H with leading products of furan + H and 1,3-butadienal + H. Equilibrium geometries, atomization energies, reaction barriers, transition states, and heats of reaction are computed using the DFT, MP2, and DMC approaches and compared to experiment. We find that DMC results are in close agreement with experiment. The kinetics of the subject reactions are determined by solving master equations with the MultiWell software suite.
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Affiliation(s)
| | - Benjamin S Lengeling
- ⊥Laboratoire de Chimie et Physique Quantiques, CNRS-IRSAMC, Université de Toulouse, Toulouse F-31062, France
| | | | - Michel Caffarel
- ⊥Laboratoire de Chimie et Physique Quantiques, CNRS-IRSAMC, Université de Toulouse, Toulouse F-31062, France
| | - Michael Frenklach
- #Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740, United States
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Capron M, Bourgalais J, Abhinavam Kailasanathan RK, Osborn DL, Le Picard SD, Goulay F. Flow tube studies of the C(3P) reactions with ethylene and propylene. Phys Chem Chem Phys 2015; 17:23833-46. [DOI: 10.1039/c5cp03918e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Product detection studies of C(3P) atom reactions with ethylene, C2H4(X1Ag) and propylene, C3H6(X1A′) are carried out in a flow tube reactor at 332 K and 4 Torr (553.3 Pa) under multiple collision conditions.
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Affiliation(s)
- Michael Capron
- Institut de Physique de Rennes
- Département de Physique Moléculaire
- Astrophysique de Laboratoire
- 35042 Rennes Cedex
- France
| | - Jérémy Bourgalais
- Institut de Physique de Rennes
- Département de Physique Moléculaire
- Astrophysique de Laboratoire
- 35042 Rennes Cedex
- France
| | | | - David L. Osborn
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Sébastien D. Le Picard
- Institut de Physique de Rennes
- Département de Physique Moléculaire
- Astrophysique de Laboratoire
- 35042 Rennes Cedex
- France
| | - Fabien Goulay
- Department of Chemistry
- West Virginia University
- Morgantown
- USA
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17
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Lockyear JF, Welz O, Savee JD, Goulay F, Trevitt AJ, Taatjes CA, Osborn DL, Leone SR. Isomer Specific Product Detection in the Reaction of CH with Acrolein. J Phys Chem A 2013; 117:11013-26. [DOI: 10.1021/jp407428v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Jessica F. Lockyear
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Oliver Welz
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - John D. Savee
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - Fabien Goulay
- Department
of Chemistry, West Virginia University, Morgantown, West Virginia, 26506, United States
| | - Adam J. Trevitt
- School
of Chemistry, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Craig A. Taatjes
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - David L. Osborn
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - Stephen R. Leone
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Departments
of Chemistry and Physics, University of California, Berkeley, California 94720, United States
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