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Bowman MC, Burke AD, Turney JM, Schaefer HF. Mechanisms of the Ethynyl Radical Reaction with Molecular Oxygen. J Phys Chem A 2018; 122:9498-9511. [PMID: 30421915 DOI: 10.1021/acs.jpca.8b09862] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ethynyl radical, •C2H, is a key intermediate in the combustion of various alkynes. Once produced, the ethynyl radical will rapidly react with molecular oxygen to produce a variety of products. This research presents the first comprehensive high level theoretical study of the reaction of the •C2H (2Σ+) radical with molecular oxygen (3Σg-). Correlation methods as complete as CCSDT(Q) were used; basis sets as large as cc-pV6Z were adopted. Focal point analysis was employed to approach relative energies within the bounds of chemical accuracy (≤1 kcal mol-1). Two dominate reaction pathways from the ethynyl peroxy radical include oxygen-oxygen cleavage from the ethynyl peroxy radical that is initially formed to produce HCCO (2A″) and O (3P) and an isomerization of the ethynyl peroxy radical to eventually yield HCO (2A') and CO (1Σ+). The branching ratio between these two competitive reaction pathways was determined to be 1:1 at 298 K. Minor reaction pathways leading to the production of CO2 (1Σg+) and CH (2Π, 4Σ-, 2Δ) were also characterized. The absence of CCO (3Σ-) and OH (2Π) was explained in terms competition with more accessible reaction pathways.
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Affiliation(s)
- Michael C Bowman
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 United States
| | - Alexandra D Burke
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 United States
| | - Justin M Turney
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 United States
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 United States
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2
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Becker KH, Wiesen P. Measurements on the CH*(A2
Δ → X2
Π) Chemiluminescence in the C2H2 + O Flame and Quenching Rate Constants for Different Reactants at 297 K. ACTA ACUST UNITED AC 2011. [DOI: 10.1524/zpch.1989.161.part_1_2.131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Arrowsmith AN, Chikan V, Leone SR. Dynamics of the CH(A2Delta) product from the reaction of C2H with O2 studied by Fourier transform visible spectroscopy. J Phys Chem A 2006; 110:7521-6. [PMID: 16774192 DOI: 10.1021/jp061246e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction C(2)H + O(2) --> CH(A(2)Delta) + CO(2) is investigated using Fourier transform visible emission spectroscopy. C(2)H radicals, produced by 193 nm photolysis of C(2)H(2), react with O(2) molecules at low total pressures to produce electronically excited CH(A(2)Delta). Observation of the CH(A(2)Delta-X(2)Pi) electronic emission to infer nascent rotational and vibrational CH(A(2)Delta) distributions provides information about energy partitioning in the CH(A(2)Delta) fragment during the reaction. The rotational and vibrational populations of the CH(A(2)Delta) product are determined by fitting the rotationally resolved experimental spectra with simulated spectra. The CH(A(2)Delta) product is found to be rotationally and vibrationally excited with T(rot) congruent with 1150 K and T(vib) congruent with 1900 K. The mechanism for this reaction proceeds through one of two five-atom intermediates and requires a crossing between electronic potential surfaces. The rotational excitation suggests a bent geometry for the final intermediate of this reaction before dissociation to products, and the vibrational excitation involves an elongation of the C-H bond from the compressed transition state to the final CH(A) state.
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Affiliation(s)
- Alan N Arrowsmith
- Department of Chemistry and Biochemistry, JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA
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4
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Chikan V, Leone SR. Vibrational and Rotational Distributions of the CH(A2Δ) Product of the C2H + O(3P) Reaction Studied by Fourier Transform Visible (FTVIS) Emission Spectroscopy. J Phys Chem A 2005; 109:10646-53. [PMID: 16863113 DOI: 10.1021/jp053444w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The C(2)H + O((3)P) --> CH(A) + CO reaction is investigated using Fourier transform visible emission spectroscopy. The O((3)P) and C(2)H radicals are produced by simultaneous 193 nm photolysis of SO(2) and C(2)H(2) precursors, respectively. The nascent vibrational and rotational distributions of the CH(A) product are obtained under time-resolved, but quasi-steady-state, conditions facilitated by the short lifetime of the CH(A) emission. The vibrational temperature of the CH(A) product is found to be appreciably hotter (2800 +/- 100 K) than the rotational distributions in the v' = 0 (1400 +/- 100 K) and v' = 1 (1250 +/- 250 K) levels. The results suggest that the reaction may proceed through an electronically excited HCCO() intermediate; moreover, the vibrational excitation compared to rotational excitation is higher than expected based on a statistical distribution of energy and may be the result of geometrical changes in the transition state. The CH(A) emission is also observed in a C(2)H(2)/O/H reaction mixture using a microwave discharge apparatus to form O atoms, with subsequent H atom production. The nascent rotational and vibrational distributions of the CH(A) determined by the microwave discharge apparatus are very similar to the CH(A) distributions obtained in the photodissociation experiment. The results support the idea that the C(2)H + O((3)P) reaction may play a role in low-pressure C(2)H(2)/O/H flames, as previously concluded.
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Affiliation(s)
- Viktor Chikan
- Departments of Chemistry and Physics, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720-1460, USA
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5
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Ma J, Liu P, Zhang M, Dai HL. Nanosecond time-resolved IR emission from molecules excited in a supersonic jet: Intramolecular dynamics of NO2 near dissociation. J Chem Phys 2005; 123:154306. [PMID: 16252947 DOI: 10.1063/1.2049271] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
IR emission from NO2 cooled in a supersonic jet and excited to a single, B 2B1 state rovibronic level at 22 994.92 cm(-1) above the ground-state zero point was detected with 10(-8)-s time resolution. The IR emission together with the laser-induced fluorescence decay measurement allows the deduction of the relaxation dynamics near the dissociation of NO2. Following the excitation this single rovibronic B 2B1 level decays on 1.0-s time scale primarily through electronic radiation. Collisions induce internal conversion with a rate constant of 3.0 x 10(7) Torr(-1) s(-1) to the mixed AX states. Collisions further induce internal conversion of the AX mixed states into highly vibrationally excited levels in the X states with a rate constant at least one order of magnitude slower. This mechanism results in the observation of a double-exponential decay in the laser-induced fluorescence and a rise in the IR emission intensity corresponding to the fast decay in the fluorescence intensity. The IR emission rate of the highly vibrationally excited X-state levels is estimated to be about one order of magnitude larger than the isoenergetic AX mixed states and much larger than the B 2B1 level, both with much less vibrational excitation.
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Affiliation(s)
- Jianqiang Ma
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-632, USA
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6
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Chikan V, Nizamov B, Leone SR. Product State Distributions of Vibrationally Excited CO(v) for the CH(X2Π) and CH(A2Δ) Channels of the C2H + O(3P) Reaction. J Phys Chem A 2004. [DOI: 10.1021/jp040317b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Viktor Chikan
- Departments of Chemistry and Physics, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720-1460
| | - Boris Nizamov
- Departments of Chemistry and Physics, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720-1460
| | - Stephen R. Leone
- Departments of Chemistry and Physics, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720-1460
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7
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Li L, Deng P, Tian A, Xu M, Wong NB. Theoretical Study on the Reaction Mechanisms of C2H with O2. J Phys Chem A 2004. [DOI: 10.1021/jp037658u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Laicai Li
- Department of Chemistry, Sichuan Normal University, Chengdu 610066, People's Republic of China, Faculty of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China, State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Ping Deng
- Department of Chemistry, Sichuan Normal University, Chengdu 610066, People's Republic of China, Faculty of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China, State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Anmin Tian
- Department of Chemistry, Sichuan Normal University, Chengdu 610066, People's Republic of China, Faculty of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China, State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Minghou Xu
- Department of Chemistry, Sichuan Normal University, Chengdu 610066, People's Republic of China, Faculty of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China, State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Ning-Bew Wong
- Department of Chemistry, Sichuan Normal University, Chengdu 610066, People's Republic of China, Faculty of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China, State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China, and Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
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8
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Affiliation(s)
- Allan H Laufer
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
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9
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Vaghjiani GL. Kinetics of CH radicals with O2: Evidence for CO chemiluminescence in the gas phase reaction. J Chem Phys 2003. [DOI: 10.1063/1.1599346] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Affiliation(s)
- Yi-hong Ding
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Xiang Zhang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Ze-sheng Li
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Xu-ri Huang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Chia-chung Sun
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
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11
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Fontijn A, Fernandez A, Ristanovic A, Randall MY, Jankowiak JT. CO Chemiluminescence and Kinetics of the C2 + O2 Reaction. J Phys Chem A 2001. [DOI: 10.1021/jp003529r] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Arthur Fontijn
- High-Temperature Reaction Kinetics Laboratory, The Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590
| | - Abel Fernandez
- High-Temperature Reaction Kinetics Laboratory, The Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590
| | - Aleksandra Ristanovic
- High-Temperature Reaction Kinetics Laboratory, The Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590
| | - Mai Y. Randall
- High-Temperature Reaction Kinetics Laboratory, The Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590
| | - Jerome T. Jankowiak
- High-Temperature Reaction Kinetics Laboratory, The Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590
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12
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Rate coefficients for the reaction of C2H with O2 at 90 K and 120 K using a pulsed Laval nozzle apparatus. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)01022-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Zhang X, Ding YH, Li ZS, Huang XR, Sun CC. Accurate ab Initio Calculations on the Rate Constants of the Direct Hydrogen Abstraction Reaction C2H + H2 → C2H2 + H. J Phys Chem A 2000. [DOI: 10.1021/jp001324c] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiang Zhang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023, People's Republic of China
| | - Yi-hong Ding
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023, People's Republic of China
| | - Ze-sheng Li
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023, People's Republic of China
| | - Xu-ri Huang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023, People's Republic of China
| | - Chia-chung Sun
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130023, People's Republic of China
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14
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Su H, Yang J, Ding Y, Feng W, Kong F. Reaction of C2H with NO and O2 studied by TR-FTIR emission spectroscopy. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00775-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Lunine JI, Yung YL, Lorenz RD. On the volatile inventory of Titan from isotopic abundances in nitrogen and methane. PLANETARY AND SPACE SCIENCE 1999; 47:1291-1303. [PMID: 11543194 DOI: 10.1016/s0032-0633(99)00052-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We analyze recently published nitrogen and hydrogen isotopic data to constrain the initial volatile abundances on Saturn's giant moon Titan. The nitrogen data are interpreted in terms of a model of non-thermal escape processes that lead to enhancement in the heavier isotope. We show that these data do not, in fact, strongly constrain the abundance of nitrogen present in Titan's early atmosphere, and that a wide range of initial atmospheric masses (all larger than the present value) can yield the measured enhancement. The enrichment in deuterated methane is now much better determined than it was when Pinto et al. (1986. Nature 319, 388-390) first proposed a photochemical mechanism to preferentially retain the deuterium. We develop a simple linear theory to provide a more reliable estimate of the relative dissociation rates of normal and deuterated methane. We utilize the improved data and models to compute initial methane reservoirs consistent with the observed enhancement. The result of this analysis agrees with an independent estimate for the initial methane abundance based solely on the present-day rate of photolysis and an assumption of steady state. This consistency in reservoir size is necessary but not sufficient to infer that methane photolysis has proceeded steadily over the age of the solar system to produce large quantities of less volatile organics. Our analysis indicates an epoch of early atmospheric escape of nitrogen, followed by a later addition of methane by outgassing from the interior. The results also suggest that Titan's volatile inventory came in part or largely from a circum-Saturnian disk of material more reducing than the surrounding solar nebula. Many of the ambiguities inherent in the present analysis can be resolved through Cassini-Huygens data and a program of laboratory studies on isotopic and molecular exchange processes. The value of, and interest in, the Cassini-Huygens data can be greatly enhanced if such a program were undertaken prior to the prime phase of the mission.
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Affiliation(s)
- J I Lunine
- Reparto di Planetologia, CNR-Istituto di Astrofisica Spaziale, Rome, Italy.
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16
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Sumathi R, Peeters J, Nguyen MT. Theoretical studies on the C2H+O2 reaction: mechanism for HCO+CO, HCCO+O and CH+CO2 formation. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00148-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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18
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Devriendt K, Peeters J. Direct Identification of the C2H(X2Σ+) + O(3P) → CH(A2Δ) + CO Reaction as the Source of the CH(A2Δ→X2Π) Chemiluminescence in C2H2/O/H Atomic Flames. J Phys Chem A 1997. [DOI: 10.1021/jp963434i] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katia Devriendt
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Jozef Peeters
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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19
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Opansky BJ, Leone SR. Rate Coefficients of C2H with C2H4, C2H6, and H2 from 150 to 359 K. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp9619604] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Brian J. Opansky
- JILA, National Institute of Standards and Technology and University of Colorado, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
| | - Stephen R. Leone
- JILA, National Institute of Standards and Technology and University of Colorado, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
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20
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Peeters J, Van Look H, Ceursters B. Absolute Rate Coefficients of the Reactions of C2H with NO and H2 between 295 and 440 K. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960201i] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jozef Peeters
- Department of Chemistry, University of Leuven, Celestijnenlaan 200 F, B-3001 Leuven, Belgium
| | - Hilde Van Look
- Department of Chemistry, University of Leuven, Celestijnenlaan 200 F, B-3001 Leuven, Belgium
| | - Benny Ceursters
- Department of Chemistry, University of Leuven, Celestijnenlaan 200 F, B-3001 Leuven, Belgium
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21
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Burke ML, Dimpfl WL, Sheaffer PM, Zittel PF, Bernstein LS. Formation of Triplet CO in Atomic Oxygen Flames of Acetylene and Carbon Suboxide. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp950363z] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. L. Burke
- The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957
| | - W. L. Dimpfl
- The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957
| | - P. M. Sheaffer
- The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957
| | - P. F. Zittel
- The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957
| | - L. S. Bernstein
- The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009-2957
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22
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Gray JA, Westbrook CK. High-temperature ignition of propane with MTBE as an additive: Shock tube experiments and modeling. INT J CHEM KINET 1994. [DOI: 10.1002/kin.550260710] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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23
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Caballero JF, Wittig C. IR multiple photon dissociation of C2HCl3: Molecular elimination vs bond fission and efficient dissociation of the C2Cl2 producta). J Chem Phys 1983. [DOI: 10.1063/1.444758] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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