Temperature dependence of the reaction of oxygen atoms with olefins

Singleton, D. L.; Cvetanović, R. J.

doi:10.1021/ja00438a006

Cited by 284 publications

(254 citation statements)

References 3 publications

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“…Indeed, many of these reactions present negative activation energies, i. e. their rate constant decreases with increasing temperature. Following the suggestion of Singleton andCvetanovic proposed in 1976 (Singleton &Cvetanovic, 1976) and using quantum chemistry methods, we showed that the existence of a stable Van der Waals pre-reactive complex in the entrance of the reaction channel explains satisfactorily the observed kinetic data. Thus, radical-molecule reactions must be seen as complex reactions consisting of more than one elementary step.…”

Section: Atmospheric Model Applications 222supporting

confidence: 80%

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

Iuga¹,

Galano²,

Alvarez-Idaboy³

et al. 2012

Atmospheric Model Applications

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Section: Atmospheric Model Applications 222supporting

confidence: 80%

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

Iuga¹,

Galano²,

Alvarez-Idaboy³

et al. 2012

Atmospheric Model Applications

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“…The recent theoretical analysis of the C 2 H 4 + OH reaction by Vivier-Bunge and co-workers, 59 building on earlier work of Singleton and Cvetanovic, 63 recognized the significance of the outer transition state preceding the van der Waals complex. Implementing a steady-state assumption for the concentration of van der Waals complexes they suggested that the overall addition rate coefficient is given by where k 1 and k -1 are the thermal rate coefficients for formation and decomposition of the van der Waals complex from reactants, while k 2 is the thermal rate coefficient for conversion of the van der Waals complex into the chemical adduct.…”

Section: Introductionmentioning

confidence: 99%

A Two Transition State Model for Radical−Molecule Reactions: Applications to Isomeric Branching in the OH−Isoprene Reaction

et al. 2007

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A two transition state model is applied to the study of the addition of hydroxyl radical to ethylene. This reaction serves as a prototypical example of a radical-molecule reaction with a negative activation energy in the high-pressure limit. The model incorporates variational treatments of both inner and outer transition states. The outer transition state is treated with a recently derived long-range transition state theory approach focusing on the longest-ranged term in the potential. High-level quantum chemical estimates are incorporated in a variational transition state theory treatment of the inner transition state. Anharmonic effects in the inner transition state region are explored with direct phase space integration. A two-dimensional master equation is employed in treating the pressure dependence of the addition process. An accurate treatment of the two separate transition state regions at the energy and angular momentum resolved level is essential to the prediction of the temperature dependence of the addition rate. The transition from a dominant outer transition state to a dominant inner transition state is predicted to occur at about 130 K, with significant effects from both transition states over the 10 to 400 K temperature range. Modest adjustment in the ab initio predicted inner saddle point energy yields theoretical predictions which are in quantitative agreement with the available experimental observations. The theoretically predicted capture rate is reproduced to within 10% by the expression [4.93 × 10 -12 (T/298) -2.488 exp(-107.9/RT) + 3.33 × 10 -12 (T/298) 0.451 exp(117.6/RT); with R ) 1.987 and T in K] cm 3 molecules -1 s -1 over the 10-600 K range.

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“…It was initially analyzed according to the scheme advocated by Singleton and Cvetanovic [86] for prereactive complexes. We assume here that the reaction occurs according to the following two-step mechanism:…”

Section: Methodsmentioning

confidence: 99%

A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH₂IBr by OH Radicals: Implications for Atmospheric Chemistry

Šulka

Šulková

Louis

et al. 2013

Zeitschrift für Physikalische Chemie

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We report the calculation of the H-, Br-, and I-abstraction channels in the reaction of OH radicals with bromoiodomethane CH 2 IBr. The resulting energy profiles at 0 K were obtained by high-level all-electron ab initio methods including valence and core-valence electron correlation, scalar relativistic effects, spin-orbit coupling, spin-adaptation, vibration contributions, and tunneling corrections. In terms of activation enthalpy at 0 K, the energy profile for the Br-abstraction showed that this reaction pathway is not energetically favorable in contrast to the two other channels (H-and I-abstractions), which are competitive. The H-abstraction was strongly exothermic (−84.4 kJ mol −1 ), while the I-abstraction was modestly endothermic (16.5 kJ mol −1 ). On the basis of our calculations, we predicted the rate constants using canonical transition state theory over the temperature range 250-500 K for each abstraction pathway. The overall rate constant at 298 K was estimated to be 3.40 × 10 −14 and 4.22 × 10 −14 cm 3 molecule −1 s −1 for complex and direct abstraction mechanisms, respectively. In addition, the overall rate constant computed at 277 K was used in the estimation of the atmospheric lifetime for CH 2 IBr. On the basis of our theoretical calculations, the atmospheric lifetime for the OH removal process is predicted to be close to 1 year. In terms of atmospheric lifetime, the OH reaction is not competitive with the Cl reaction and photolysis processes.

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Temperature dependence of the reaction of oxygen atoms with olefins

Cited by 284 publications

References 3 publications

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

A Two Transition State Model for Radical−Molecule Reactions: Applications to Isomeric Branching in the OH−Isoprene Reaction

A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH₂IBr by OH Radicals: Implications for Atmospheric Chemistry

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Temperature dependence of the reaction of oxygen atoms with olefins

Cited by 284 publications

References 3 publications

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

Reactivity Trends in Radical-Molecule Tropospheric Reactions - A Quantum Chemistry and Computational Kinetics Approach

A Two Transition State Model for Radical−Molecule Reactions: Applications to Isomeric Branching in the OH−Isoprene Reaction

A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH2IBr by OH Radicals: Implications for Atmospheric Chemistry

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A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH₂IBr by OH Radicals: Implications for Atmospheric Chemistry