Rate Constants for the Reactions of CH2 (X̄3B1) with Selected Alkenes at Temperatures Between 296 K≤T≤728 K

Kraus, H.; Oehlers, C.; Temps, F.; Wagner, H. Gg.; Wolf, Maarten G.

doi:10.1002/bbpc.19930970402

Cited by 6 publications

(2 citation statements)

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“…Detection of CH 2 radical has been tried by using various techniques (LMR spectrometers, mass spectrometers, infrared diode laser absorption for 3 CH 2 , and LIF and others for 1 CH 2 ); a large amount of information about the rate constants and reaction mechanism of CH 2 radical have been accumulated at low temperature range. − Also, shock tube works combined with ARAS (atomic resonance absorption spectrometry) and the frequency modulation spectroscopy have been conducted to explore the CH 2 reactions above 1000 K. − , …”

Section: Introductionmentioning

confidence: 99%

Study on the Reaction of CH₂ with H₂ at High Temperature

2012

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Thermal decomposition of CH(2)I(2) [sequential C-I bond fission processes, CH(2)I(2) + Ar → CH(2)I + I + Ar (1a) and CH(2)I + Ar → (3)CH(2) + I + Ar (1b)], and the reactions of (3)CH(2) + H(2) → CH(3) + H (2) and (1)CH(2) + H(2) → CH(3) + H (3) have been studied by using atomic resonance absorption spectrometry (ARAS) of I and H atoms behind reflected shock waves. Highly diluted CH(2)I(2) (0.1-0.4 ppm) with/without excess H(2) (300 ppm) in Ar has been used so that the effect of the secondary reactions can be minimized. From the quantitative measurement of I atoms in the 0.1 ppm CH(2)I(2) + Ar mixture over 1550-2010 K, it is confirmed that two-step sequential C-I bond fission processes of CH(2)I(2), (1a) and (1b), dominate over other product channels. The decomposition step (1b) is confirmed to be the rate determining process to produce (3)CH(2) and the least-squares analysis of the measured rate gives, ln(k(1b)/cm(3) molecule(-1) s(-1)) = -(17.28 ± 0.79) - (30.17 ± 1.40) × 10(3)/T. By utilizing this result, we examine reactions 2 and 3 by monitoring evolution of H atoms in the 0.2-0.4 ppm CH(2)I(2) + 300 ppm H(2) mixtures over 1850-2040 K. By using a theoretical result on k(2) (Lu, K. W.; Matsui, H.; Huang, C.-L.; Raghunath, P.; Wang, N.-S.; Lin, M. C. J. Phys. Chem. A 2010, 114, 5493), we determine the rate for (3) as k(3)/cm(3) molecule(-1) s(-1) = (1.27 ± 0.36) × 10(-10). The upper limit of k(3) (k(3max)) is also evaluated by assuming k(2) = 0, i.e., k(3max)/cm(3) molecule(-1) s(-1) = (2.26 ± 0.59) × 10(-10). The present experimental results on k(3) and k(3max) is found to agree very well with the previous frequency modulation spectroscopy study (Friedrichs, G.; Wagner, H. G. Z. Phys. Chem. 2001, 215, 1601); i.e., the importance of the contribution of (1)CH(2) in the reaction of CH(2) with H(2) at elevated temperature range is reconfirmed.

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Section: Introductionmentioning

confidence: 99%

Study on the Reaction of CH₂ with H₂ at High Temperature

2012

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“…In contrast, the activation energies for the 3CH2 reactions with various monoalkenes seem to lie in a narrow energy band. 10 Because of the different behavior for the reactions of 0(3P) and CH2(3Bi) with monoalkenes, the question arises, whether the two reaction mechanisms are the same. To clarify this question, accurate potential energy surfaces for both reactions 0(3P) and CH2(3Bi) with alkenes will be very helpful.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of the Reaction O(3P) + C2H4 and Comparison with the 3CH2 + C2H4 Reaction

Wortmann-Saleh¹,

Engels²,

Peyerimhoff³

1994

J. Phys. Chem.

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The minimum energy path for the reaction O(lP g) + C 2~( 1 Ag) has been calculated by optimizing all relevant geometrical parameters along the approach of oxygen to ethene. A barrier of 4.7 kcallmol in the 3 A"( ... 9a' 2 -10a'3a") potential energy surface and an energy difference of 14.4 kcal/mol between the product and the fragments is found at the multireference-configuration interaction Ievel. The corresponding values at the lower-level treatment CASSCF are 9 kcaVmol for the barrier and 9 kcaL'mol for the depth of the potential; this shows the importance of inclusion of electron correlation. The barrier for CH2 rotation for the lowestenergy structure (asymmetric OC 2~) is around 5 kcaL'mol. The energy gap to the first excited state 3 A'-( ... 9a'l0a'3a'12) is found tobe 3.6 kcaL'mol in MRD-CI calculations at the ground-state minimum. Comparison with 3 CH 2 + C 2~ shows that in this system the lowest-energy surface is 3 A', i.e., the state which is the excited state in 0 + C 2~. This difference in energy ordering of 3 A' and 3 A" states results from the fact that the Px• py, Pz degeneracy of oxygen orbitals is lifted in 3 CH2leading to b1, h2. and a1 MOs whereby the lowest b 2 (a") remains doubly occupied; as a consequence, the reaction pattem between the oxygen and 3 CH 2 approach is different, which is also quite apparent in· the calculated charge transfer.

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A Kinetic Study About the Reactions of NH(X³Σ⁻) with Hydrocarbons Part 3: Benzene, 1,3‐Butadiene and Acetylene

Röhrig¹,

Römming²,

Wagner³

1995

Ber Bunsenges Phys Chem

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The reactions of NH in its electronic ground state with benzene (1), 1,3‐butadiene (2) and acetylene (3) were investigated behind incident shock waves using narrow line width absorption detection of NH(X3Σ). The experiments were performed with very low initial concentrations of HN3 which was used as NH(X3Σ−) source to reduce the influence of secondary reactions. Thus it became possible to measure kinetic data for the reactions of NH (X3Σ−) with these hydrocarbons directly. The following rate constants were obtained in the temperature range 1100 to 1500 K, resp. 1400 to 1700 K (acetylene): k1 = 10(14.2±0.3) exp (‐(76±8) kJ mol−1/RT) cm3/mol s k2 = 10(13.9±0.3) exp (‐(45±7) kJ mol−1/RT) cm3/mol s k3 = 10(14.7±0.3) exp (‐(59±9) kJ mol−1/RT) cm3/mol s

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Rate Constants for the Reactions of CH₂ (X̄³B₁) with Selected Alkenes at Temperatures Between 296 K≤T≤728 K

Cited by 6 publications

References 28 publications

Study on the Reaction of CH₂ with H₂ at High Temperature

Study on the Reaction of CH₂ with H₂ at High Temperature

Theoretical Study of the Reaction O(3P) + C2H4 and Comparison with the 3CH2 + C2H4 Reaction

A Kinetic Study About the Reactions of NH(X³Σ⁻) with Hydrocarbons Part 3: Benzene, 1,3‐Butadiene and Acetylene

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Rate Constants for the Reactions of CH2 (X̄3B1) with Selected Alkenes at Temperatures Between 296 K≤T≤728 K

Cited by 6 publications

References 28 publications

Study on the Reaction of CH2 with H2 at High Temperature

Study on the Reaction of CH2 with H2 at High Temperature

Theoretical Study of the Reaction O(3P) + C2H4 and Comparison with the 3CH2 + C2H4 Reaction

A Kinetic Study About the Reactions of NH(X3Σ−) with Hydrocarbons Part 3: Benzene, 1,3‐Butadiene and Acetylene

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Rate Constants for the Reactions of CH₂ (X̄³B₁) with Selected Alkenes at Temperatures Between 296 K≤T≤728 K

Study on the Reaction of CH₂ with H₂ at High Temperature

Study on the Reaction of CH₂ with H₂ at High Temperature

A Kinetic Study About the Reactions of NH(X³Σ⁻) with Hydrocarbons Part 3: Benzene, 1,3‐Butadiene and Acetylene