Reaction rate determinations of vinyl radical reactions with vinyl, methyl, and hydrogen atoms

Fahr, Askar; Laufer, Allan H.; Klein, Robert J.; Braun, W.

doi:10.1021/j100161a047

Cited by 106 publications

(130 citation statements)

References 5 publications

Supporting

Mentioning

115

Contrasting

Order By: Relevance

“…The value k 1 (298 K, 1 Torr) ϭ (1.02 Ϯ 0.53) ϫ 10 Ϫ10 cm 3 molecule -1 s -1 reported here for the reaction between CH 3 and C 2 H 3 is in fair agreement with both values measured by Fahr et al [24,25] at higher pressures, as shown in Table III. An earlier relative rate measurement based on complex analysis has been neglected [59].…”

Section: Discussionsupporting

confidence: 91%

“…⌬H (298 K ) ϭ Ϫ13.3 kcal mol [23] r Previous studies of the CH 3 ϩ C 2 H 3 reaction are few and limited to relatively high pressures: P ϭ 100 Torr of He [24] and P ϭ 100 to 300 Torr of He or Ar [25]. These T ϭ 298 K studies yield a total rate constant k 1 ϭ 1.5 ϫ 10 Ϫ10 cm 3 molecule Ϫ1 s Ϫ1 .…”

Section: Introductionmentioning

confidence: 99%

“…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%

See 2 more Smart Citations

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.

View full text Add to dashboard Cite

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

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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.

View full text Add to dashboard Cite

show abstract

“…11, lla 21-23,37-39, 101-103 64,75,76,79-81,83,85, 88,90, 122, 123, 126-128, 133, 137, 138, 141, 148-151, 153, 155, 167 C2Hi ( Table 2 of Marinov et al [21], C, (a = 1-4) refers to the number of carbon atoms in the primary reactant, additional reactions listed here are modifications to the original Marinov mechanism [38,39].…”

Section: Results Of Numerical Experimentsmentioning

confidence: 99%

The Autocatalytic Behavior of Trimethylindium During Thermal Decomposition

McDaniel¹,

Allendorf²

2000

View full text Add to dashboard Cite

“…Problems may arise when one seeks to extrapolate the results to different temperatures. Reactions without barriers (such as for bond breaking) lead to A factors and activation energies that decrease with temperature [24]. The reverse is true for those with barriers.…”

Section: Discussionmentioning

confidence: 99%