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Modeling the influence of resonance stabilization on the kinetics of hydrogen abstractions

Maarten Sabbe (UGent) , Aäron Vandeputte (UGent) , Marie-Françoise Reyniers (UGent) , Michel Waroquier (UGent) and Guy Marin (UGent)
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Abstract
Resonance stabilization of the transition state is one of the key factors in modeling the kinetics of hydrogen abstraction reactions between hydrocarbons. A group additive model is developed which allows the prediction of rate coefficients for bimolecular hydrogen abstraction reactions over a broad range of hydrocarbons and hydrocarbon radicals between 300 and 1300 K. Group additive values for 50 groups are determined from rate coefficients determined using the high level CBS-QB3 ab initio method, corrected for tunneling and the hindered internal rotation around the transitional bond. Resonance and hyperconjugative stabilization of the transition state is accounted for by introducing 4 corrections based on the structure of the reactive moiety of the transition state. The corrections, fitted to a set of 28 reactions, are temperature-independent and reduce the mean absolute deviation on E-a to 0.7 kJ mol(-1) and to 0.05 for log A. Tunneling contributions are accounted for by using a fourth order polynomial in the activation energy. Final validation for 19 reactions yields a mean factor of deviation between group additive prediction and ab initio calculation of 2.4 at 300 K and 1.8 at 1000 K. In comparison with 6 experimental rate coefficients (600-719 K), the mean factor of deviation is less than 3.
Keywords
CENTERED RADICAL-ADDITION, TRANSITION-STATE THEORY, THEORETICAL PROCEDURES, REACTION-RATE PREDICTION, BETA-SCISSION REACTIONS, AB-INITIO, STATISTICAL FACTORS, THERMAL-REACTION, ACTIVATION-ENERGIES, THERMOCHEMICAL PROPERTIES

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Chicago
Sabbe, Maarten, Aäron Vandeputte, Marie-Françoise Reyniers, Michel Waroquier, and Guy Marin. 2010. “Modeling the Influence of Resonance Stabilization on the Kinetics of Hydrogen Abstractions.” Physical Chemistry Chemical Physics 12 (6): 1278–1298.
APA
Sabbe, Maarten, Vandeputte, A., Reyniers, M.-F., Waroquier, M., & Marin, G. (2010). Modeling the influence of resonance stabilization on the kinetics of hydrogen abstractions. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 12(6), 1278–1298.
Vancouver
1.
Sabbe M, Vandeputte A, Reyniers M-F, Waroquier M, Marin G. Modeling the influence of resonance stabilization on the kinetics of hydrogen abstractions. PHYSICAL CHEMISTRY CHEMICAL PHYSICS. 2010;12(6):1278–98.
MLA
Sabbe, Maarten, Aäron Vandeputte, Marie-Françoise Reyniers, et al. “Modeling the Influence of Resonance Stabilization on the Kinetics of Hydrogen Abstractions.” PHYSICAL CHEMISTRY CHEMICAL PHYSICS 12.6 (2010): 1278–1298. Print.
@article{869755,
  abstract     = {Resonance stabilization of the transition state is one of the key factors in modeling the kinetics of hydrogen abstraction reactions between hydrocarbons. A group additive model is developed which allows the prediction of rate coefficients for bimolecular hydrogen abstraction reactions over a broad range of hydrocarbons and hydrocarbon radicals between 300 and 1300 K. Group additive values for 50 groups are determined from rate coefficients determined using the high level CBS-QB3 ab initio method, corrected for tunneling and the hindered internal rotation around the transitional bond. Resonance and hyperconjugative stabilization of the transition state is accounted for by introducing 4 corrections based on the structure of the reactive moiety of the transition state. The corrections, fitted to a set of 28 reactions, are temperature-independent and reduce the mean absolute deviation on E-a to 0.7 kJ mol(-1) and to 0.05 for log A. Tunneling contributions are accounted for by using a fourth order polynomial in the activation energy. Final validation for 19 reactions yields a mean factor of deviation between group additive prediction and ab initio calculation of 2.4 at 300 K and 1.8 at 1000 K. In comparison with 6 experimental rate coefficients (600-719 K), the mean factor of deviation is less than 3.},
  author       = {Sabbe, Maarten and Vandeputte, A{\"a}ron and Reyniers, Marie-Fran\c{c}oise and Waroquier, Michel and Marin, Guy},
  issn         = {1463-9076},
  journal      = {PHYSICAL CHEMISTRY CHEMICAL PHYSICS},
  keyword      = {CENTERED RADICAL-ADDITION,TRANSITION-STATE THEORY,THEORETICAL PROCEDURES,REACTION-RATE PREDICTION,BETA-SCISSION REACTIONS,AB-INITIO,STATISTICAL FACTORS,THERMAL-REACTION,ACTIVATION-ENERGIES,THERMOCHEMICAL PROPERTIES},
  language     = {eng},
  number       = {6},
  pages        = {1278--1298},
  title        = {Modeling the influence of resonance stabilization on the kinetics of hydrogen abstractions},
  url          = {http://dx.doi.org/10.1039/b919479g},
  volume       = {12},
  year         = {2010},
}

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