Theoretical Investigations on Removal Reactions of Ethenol by H Atom

Abstract

Ethenol is a recently identified combustion intermediate. However, its chemistry remains unclear. In present work, the removal reactions of ethenol by H atom are investigated. The geometries of all species involved in the reaction are optimized at B3LYP/6-311++G(d,p), and their single point energies are extrapolated to the infinite-basis-set limit at the level CCSD(T). Energies are also calculated at G3B3, CBS-APNO, and CCSD(T)/6-311++G(3df, 2p) for comparison. A total of six elementary reactions, including four abstractions and two additions, with explicit transition states are investigated. The results show that the reactions are selective: for abstractions, the hydrogen atom, linked to the oxygen atom, is the most reactive; while for additions, the preferred carbon site is the head "CH(2)═". The rate constants are estimated in the temperature range 300-3000 K according to the conventional transition state theory with the Eckart tunneling model. The dominant channels are the two additions in the whole temperature range. The abstractions can be competitive at high temperature but still do not dominate. The calculated rate constants for the reverse reaction of (R6), syn-CH(2)═CHOH + H ↔ CH(3)·CHOH, are consistent with the available literature values. Finally, the Fukui functions are calculated to analyze the site reactivity.

A Hierarchical and Comparative Kinetic Modeling Study of C1 − C2 Hydrocarbon and Oxygenated Fuels

“…Reactions of vinyl alcohol with atom, H 2 radical, and its isomerization to acetaldehyde have been taken from Rao et al. , da Silva and Bozzelli , and Shao et al. , respectively.…”

“…The reactions of vinyl alcohol will not be described in detail here as it does not significantly affect the reactivity of the alkanes/alkenes. Reactions of vinyl alcohol withḢ atom, HȮ 2 radical, and its isomerization to acetaldehyde have been taken from Rao et al [135], da Silva and Bozzelli [136], and Shao et al [137], respectively. Other abstraction reaction rate coefficients were applied by analogy to other systems.…”

Theoretical study of the oxidation mechanisms of naphthalene initiated by hydroxyl radicals: the O2 addition reaction pathways

“…TST gives an estimate of the upper-limit for rate constants as a function of the temperature, and is known to give reliable estimations of rate constants 66,67 in the high pressure limit, 68 especially for cases with significant barrier heights (as is the case here). 69 All supplied rate constants are the results of calculations that were performed using the implementation of this approach in the Kinetic and Statistical Thermodynamical Package (KiSThelP) by Canneaux et al 70 Besides TST, in the present study, statistical RRKM theory [42][43][44] has been considered to evaluate pressure effects on a microcanonical basis, both in the fall-off regime and towards the high pressure limit, using the implementation of this approach in the KiSThelP program. 70 In these RRKM calculations, a scaling factor of 0.971 was imposed on the frequencies calculated at the UM06-2x/aug-cc-pVTZ level of theory.…”

Automated chemical resonance generation and structure filtration for kinetic modeling

“…Rate coefficients for hydrogen abstraction from molecular hydrogen by ethoxy and vinoxy radicals. The rate coefficient for vinoxy was determined from the reverse reaction using appropriate thermodynamic data [Color figure can be viewed at wileyonlinelibrary.com]…”