Direct rate measurements of the combination and disproportionation of vinyl radicals

Fahr, Askar; Laufer, Allan H.

doi:10.1021/j100365a040

Cited by 32 publications

(35 citation statements)

References 2 publications

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“…This is reasonable considering that the experimental rates were obtained relative to that of vinyl recombination with an assumed rate constant of 2 ϫ 10 13 cm 3 mol Ϫ1 s Ϫ1 . Recent studies [87,88] showed that the vinyl-recombination [84,85]. The rate coefficients for the production of p-C 3 H 4 and a-C 3 H 4 ϩ CH 3 and the two H-abstraction reactions were estimated from previous studies [2,49].…”

Section: Rrkm Analysis Of Reaction 13-c 4 H 6 ؉ Hmentioning

confidence: 99%

Detailed kinetic modeling of 1,3-butadiene oxidation at high temperatures

Laskin

Hai

Law

2000

Int. J. Chem. Kinet.

150

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Section: Rrkm Analysis Of Reaction 13-c 4 H 6 ؉ Hmentioning

confidence: 99%

Detailed kinetic modeling of 1,3-butadiene oxidation at high temperatures

Laskin

Hai

Law

2000

Int. J. Chem. Kinet.

150

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“…(105) is a fit through the available rate expression in the literature [37,38,39]. (105) C2Hs + HOz * CzHs + HzOz The kinetics of vinyl radicals self-reaction has recently been measured by Fahr and Laufer [40]; their rate constants are used here.…”

Section: The Reaction Mechanismmentioning

confidence: 99%

“…(105) C2Hs + HOz * CzHs + HzOz The kinetics of vinyl radicals self-reaction has recently been measured by Fahr and Laufer [40]; their rate constants are used here.…”

Section: (26) H C O + M -H + C O + Mmentioning

confidence: 99%

Kinetics of ethane oxidation

Dagaut

Cathonnet

Boettner

1991

Int J of Chemical Kinetics

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Ethane oxidation in jet-stirred reactor has recently been investigated at high temperature (800-1200 K) in the pressure range 1-10 atm and molecular species (HZ, CO, Con, CH,, G H z , CzH4, C2H6) concentration profiles were obtained by probe sampling and GC analysis. Ethane oxidation was modeled using a comprehensive kinetic reaction mechanism including the most recent findings concerning the kinetics of the reactions involved in the oxidation of CI -C, hydrocarbons. The proposed mechanism is able to reproduce experimental data obtained in our high-pressure jet stirred reactor and ignition delay times measured in shock tube in the pressure range 1-13 atm, for temperatures extending from 800 to 2000 K and equivalence ratios of 0.1 to 2. It is also able to reproduce atoms concentrations (H,O) measured in shock tube at =2 atm. The same detailed kinetic mechanism can also be used to model the oxidation of methane, ethylene, propyne, and allene in similar conditions.

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“…Thus, the combination reaction H ϩ C 2 H 3 : C 2 H 4 was uniformly neglected relative to abstraction at low pressures in all atmospheric models, but we measured a significant branching fraction for this channel at both T ϭ 298 K (⌫ comb ϭ 0.33) and at T ϭ 213 K (⌫ comb ϭ 0.24) [17]; a recent theoretical study of this reaction suggests combination branching fractions about an order of magnitude lower [18]. Conversely, the combination reaction C 2 H 3 ϩ C 2 H 3 : C 4 H 6 (1,3-butadiene) was uniformly included in all atmospheric models based on laboratory results at higher temperature (T ϭ 298K) and higher pressure (P ϭ 100 and 400 Torr of He) [24,26]. However, we have shown the absence of this reaction channel (⌫ comb Ͻ 0.01) at P ϭ 1 Torr for both T ϭ 298K [22] and T ϭ 200 K (see results section).…”

Section: Introductionmentioning

confidence: 99%

Rate constant and RRKM product study for the reaction between CH3 and C2H3 at T = 298 K

Thorn

Payne

Chillier

et al. 2000

Int. J. Chem. Kinet.

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The total rate constant k 1 has been determined at P ϭ 1 Torr nominal pressure (He) and at T ϭ 298 K for the vinyl-methyl cross-radical reaction: (1) CH 3 ϩ C 2 H 3 : Products. The measurements were performed in a discharge flow system coupled with collision-free sampling to a mass spectrometer operated at low electron energies. Vinyl and methyl radicals were generated by the reactions of F with C 2 H 4 and CH 4 , respectively. The kinetic studies were performed by monitoring the decay of C 2 H 3 with methyl in excess, 6 Ͻ [CH 3 ] 0 / [C 2 H 3 ] 0 Ͻ 21. The overall rate coefficient was determined to be k 1 (298 K) ϭ (1.02 Ϯ 0.53) ϫ 10 Ϫ10 cm 3 molecule Ϫ1 s Ϫ1 with the quoted uncertainty representing total errors. Numerical modeling was required to correct for secondary vinyl consumption by reactions such as C 2 H 3 ϩ H and C 2 H 3 ϩ C 2 H 3 . The present result for k 1 at T ϭ 298 K is compared to two previous studies at high pressure (100-300 Torr He) and to a very recent study at low pressure (0.9-3.7 Torr He).Comparison is also made with the rate constant for the similar reaction CH 3 ϩ C 2 H 5 and with a value for k 1 estimated by the geometric mean rule employing values for k(CH 3 ϩ CH 3 ) and k(C 2 H 3 ϩ C 2 H 3 ). Qualitative product studies at T ϭ 298 K and 200 K indicated formation of C 3 H 6 , C 2 H 2 , and C 3 H 5 as products of the combination-stabilization, disproportionation, and combination-decomposition channels, respectively, of the CH 3 ϩ C 2 H 3 reaction. We also observed the secondary C 4 H 8 product of the subsequent reaction of C 3 H 5 with excess CH 3 ; this observation provides convincing evidence for the combination-decomposition channel yielding C 3 H 5 ϩ H. RRKM calculations with helium as the deactivator support the present and very recent experimental observations that allylic C-H bond rupture is an important path in the combination reaction. The pressure and temperature dependencies of the branching fractions are also predicted. . Reaction rate constants and product channel information are required for all such models that attempt to account quantitatively for the observed atmospheric composition and structure. Hydrocarbon photochemistry is initiated by the photodissociation of methane in the upper

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Direct rate measurements of the combination and disproportionation of vinyl radicals

Cited by 32 publications

References 2 publications

Detailed kinetic modeling of 1,3-butadiene oxidation at high temperatures

Detailed kinetic modeling of 1,3-butadiene oxidation at high temperatures

Kinetics of ethane oxidation

Rate constant and RRKM product study for the reaction between CH3 and C2H3 at T = 298 K

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