Quantum chemical and conventional TST calculations of rate constants for the OH+alkane reaction

Bravo-Pérez, Graciela; Álvarez-Idaboy, J. Raúl; Galano, Annia; Cruz-Torres, Armando

doi:10.1016/j.chemphys.2004.10.031

Cited by 32 publications

(37 citation statements)

References 21 publications

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“…At the CCSD(T)//BH and HLYP level, the activation energies (E a ) for EB-H-S1 and EB-H-S2 are 2.08 and 1.38 kcal mol À1 , respectively. BravoPérez et al [37] caculated the barrier height of 3.53, 2.05, and 2.54 kcal mol À1 for methane, ethane, and toluene hydrogen abstraction, respectively, only slightly higher than our calculations.…”

Section: Side Chain Hydrogen Abstractioncontrasting

confidence: 60%

“…Vibrational frequencies and absolute energies of all reactants and TSs are provided in Supporting Information. The side chain transition states turn out to be similar to the ones previously obtained for OH abstraction of a primary hydrogen atom from alkanes and toluene [26,37]. In Table II, geometrical parameters for the abstraction transition state in methane, ethane, for the primary hydrogen atoms in propane and toluene are also reported for comparison.…”

Section: Side Chain Hydrogen Abstractionmentioning

confidence: 57%

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Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

Huang

Wang

Hao

et al. 2010

Int J of Quantum Chemistry

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ABSTRACT:The OH hydrogen abstraction and addition with ethylbenzene have been studied in the range 298-1000 K using quantum chemistry methods. The geometries and frequencies of the reactants, transition states, and products were performed at BH and HLYP/6-311þþG(d,p) level, single point calculation for all the stationary points were carried out at CCSD(T) calculations of the optimized structures with the same basis set. Nine different reaction paths are considered corresponding to two side chain, three possible ring hydrogen abstraction, and four kinds different OH addition. The results of the theoretical study indicate that at the room temperature the reaction proceeds almost exclusively through OH addition, and is predicted to occur dominantly at the ortho position, the calculated overall rate constant is 6.72 Â 10 À12 cm 3 molecule À1 s À1 , showing a very good agreement with available experimental data. Although negligible at low temperature, at 1000 K ring hydrogen abstraction accounts for about 32% of the total abstraction reaction, and the whole hydrogen abstraction makes up for 30% of the total reaction. This study may provide useful information on understanding the mechanistic features of OH-initiated oxidation of ethylbenzene.

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Section: Side Chain Hydrogen Abstractioncontrasting

confidence: 60%

Section: Side Chain Hydrogen Abstractionmentioning

confidence: 57%

Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

Huang

Wang

Hao

et al. 2010

Int J of Quantum Chemistry

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“…We were unable to locate a transition state using the B3-LYP functional for the tertiary H abstraction in i-C 4 H 10 . Recent studies by Bravo-Perez et al [45] and Huynh et al [46] have utilized the BH&HLYP functional to characterize this tertiary abstraction. Consequently we have also used the BH&HLYP functional with the 6-311+G(d, p) basis set as well as HF/6-31G(d) and MP2(Full)/6-31G(d) levels of theory to characterize the transition state geometry for this tertiary abstraction.…”

Section: Theorymentioning

confidence: 99%

High temperature rate constants for OH+ alkanes

Sivaramakrishnan

Srinivasan

et al. 2009

Proceedings of the Combustion Institute

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“…[1][2][3] Assessment of the impact of these chloroalkanes on the atmospheric environment requires accurate kinetic and mechanistic data over appropriate ranges of temperature. Although a broad kinetic data are available for the reactions of OH radicals with pure hydrocarbons [4,5] and to a lesser extent for reactions with haloalkanes, [6,7] there are limited reports on the reactions including more than two carbon atoms, particularly for the temperature-dependence rate constants. Reactions CH 3 CH 2 CH 2 Cl þ OH (R1) and CH 3 CHClCH 3 þ OH (R2) have been studied by three groups; k 1 and k 2 were measured at 303 K by Donaghy et al [8] and in the temperature ranges of 295-353 K and 233-372 K by Markert and Nielsen [9] and Mu and Mellouki, [10] respectively.…”

Section: Introductionmentioning

confidence: 98%

Hydrogen abstraction reactions of OH radicals with CH₃CH₂CH₂Cl and CH₃CHClCH₃: A mechanistic and kinetic study

Wang

et al. 2011

J Comput Chem

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The hydrogen abstraction reactions of OH radicals with CH₃CH₂CH₂Cl and CH₃CHClCH₃ (R2) have been investigated theoretically by a dual-level direct dynamics method. The optimized geometries and frequencies of the stationary points are calculated at the B3LYP/6-311G(d,p) level. To improve the reaction enthalpy and potential barrier of each reaction channel, the single point energy calculation is performed by the BMC-CCSD method. Using canonical variational transition-state theory (CVT) with the small-curvature tunneling correction, the rate constants are evaluated over a wide temperature range of 200-2000 K at the BMC-CCSD//B3LYP/6-311G(d,p) level. For the reaction channels with the negative barrier heights, the rate constants are calculated by using the CVT. The calculated total rate constants are consistent with available experimental data. The results show that at lower temperatures, the tunneling correction has an important contribution in the calculation of rate constants for all the reaction channels with the positive barrier heights, while the variational effect is found negligible for some reaction channels. For reactions OH radicals with CH₃CH₂CH₂Cl (R1) and CH₃CHClCH₃ (R2), the channels of H-abstraction from -CH₂ - and -CHCl groups are the major reaction channels, respectively, at lower temperatures. With temperature increasing, contributions from other channels should be taken into account. Finally, the total rate constants are fitted by two models, i.e., three-parameter and four-parameter expressions. The enthalpies of formation of the species CH₃CHClCH₂, CH₃CHCH₂Cl, and CH₃CH₂CH₂Cl are evaluated by isodesmic reactions.

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Quantum chemical and conventional TST calculations of rate constants for the OH+alkane reaction

Cited by 32 publications

References 21 publications

Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

High temperature rate constants for OH+ alkanes

Hydrogen abstraction reactions of OH radicals with CH₃CH₂CH₂Cl and CH₃CHClCH₃: A mechanistic and kinetic study

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Quantum chemical and conventional TST calculations of rate constants for the OH+alkane reaction

Cited by 32 publications

References 21 publications

Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

Theoretical investigation on the mechanism and kinetics of OH radical with ethylbenzene

High temperature rate constants for OH+ alkanes

Hydrogen abstraction reactions of OH radicals with CH3CH2CH2Cl and CH3CHClCH3: A mechanistic and kinetic study

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Hydrogen abstraction reactions of OH radicals with CH₃CH₂CH₂Cl and CH₃CHClCH₃: A mechanistic and kinetic study