Differences in the torsional anharmonicity between reactant and transition state: the case of 3-butenal + H abstraction reactions

2021 ◽  
Author(s):  
Maiara Oliveira Passos ◽  
Igor Araujo Lins ◽  
Mateus Fernandes Venâncio ◽  
Tiago Vinicius Alves
Keyword(s):  
Hydrogen Atom ◽  
Transition State ◽  
Hydrogen Abstraction ◽  
Rate Coefficients ◽  
Variational Theory ◽  
Small Curvature

Thermal rate coefficients for the hydrogen abstraction reactions of 3-butenal by hydrogen atom were obtained applying the multipath canonical variational theory with small-curvature tunneling (MP-CVT/SCT). Torsional anharmonicity due to the...

Rate coefficients and product branching ratios for (E)-2-butenal + H reactions

2020 ◽  
Vol 22 (25) ◽  
pp. 14246-14254
Author(s):  
Maiara Oliveira Passos ◽  
Igor Araujo Lins ◽  
Tiago Vinicius Alves
Keyword(s):  
Rate Constants ◽  
Hydrogen Abstraction ◽  
Branching Ratios ◽  
Rate Coefficients ◽  
Variational Theory ◽  
Hydrogen Atoms ◽  
Small Curvature ◽  
Thermal Rate Constants ◽  
First Time ◽  
Product Branching

Thermal rate constants for the hydrogen abstraction reactions of (E)-2-butenal by hydrogen atoms were calculated, for the first time, using the multipath canonical variational theory with small-curvature tunneling (MP-CVT/SCT).

Atmospheric chemistry of CF3(CX2)2CH2OH: rate coefficients and temperature dependence of reactions with chlorine atoms and the subsequent pathways of alkyl and alkoxy radicals (X = H, F)

RSC Advances ◽  
2016 ◽  
Vol 6 (68) ◽  
pp. 63954-63964 ◽  
Author(s):  
Feng-Yang Bai ◽  
You-Jun Liu ◽  
Xu Wang ◽  
Yan-Qiu Sun ◽  
Xiu-Mei Pan
Keyword(s):  
Transition State ◽  
Temperature Dependence ◽  
Atmospheric Chemistry ◽  
Density Functional ◽  
Rate Coefficients ◽  
Kinetic Properties ◽  
Chlorine Atoms ◽  
Alkoxy Radicals ◽  
Small Curvature ◽  
Variational Transition State

The atmospheric and kinetic properties of CF3(CX2)2CH2OH (X = H, F) with chlorine atoms were studied by density functional and canonical variational transition state theories in conjunction with the small-curvature tunneling correction.

scholarly journals Theoretical studies on the kinetics of the hydrogen-abstraction reactions from 1,3,5-trioxane and 1,4-dioxane by OH radicals

2020 ◽  
Vol 45 ◽  
pp. 146867831989925 ◽  
Author(s):  
Vahid Saheb ◽  
Aidin Bahadori
Keyword(s):  
Transition State ◽  
Transition State Theory ◽  
Hydrogen Abstraction ◽  
Transition States ◽  
State Theory ◽  
Rate Coefficients ◽  
Cyclic Ethers ◽  
Oh Radicals ◽  
Kinetics Of ◽  
Bonded Complexes

Theoretical investigations have been performed on the kinetics of bimolecular hydrogen-abstraction reactions of 1,3,5-trioxane and 1,4-dioxane cyclic ethers with OH radicals. Hydrogen abstraction from both axial and equatorial positions of 1,3,5-trioxane and 1,4-dioxane was considered. Optimization of the structures, and the calculation of energies, vibrational frequencies and moments of inertia for all the stationary points including reactants, hydrogen-bonded complexes, transition states and products were carried out using density functional theory at the M06-2X level together with the MG3S basis set. Single-point energy calculations on the optimized points were obtained at the CBS-QB3 level. The calculations show that the title reactions proceed through relatively strong hydrogen-bonded complexes due to the hydrogen bonding between the OH radicals and the oxygen atoms of the cyclic ethers. A two-transition state model (an inner tight transition state and an outer loose transition state) was employed to compute the hydrogen-abstraction rate coefficients. The rate coefficients were also computed using conventional transition state theory considering a tight transition state for the purpose of comparison. It was found that when the reactions proceed via inner transition states with relative energies higher than the reactants, the computed rate coefficients are underestimated by conventional transition state theory.

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