Theoretical studies on the mechanism and kinetics of the hydrogen abstraction reactions of threo -CF 3 CHFCHFC 2 F 5 and erythro-CF 3 CHFCHFC 2 F 5 (HFC-43-10mee) by OH radicals

Hashemi, S. Rasoul; Saheb, Vahid

doi:10.1016/j.comptc.2017.09.014

Cited by 8 publications

(6 citation statements)

References 19 publications

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“…51 The M06-2X method has been widely used in the computation of atmospheric reactions and proven to provide reliable results. [52][53][54][55][56] Harmonic vibrational analyses were conducted to provide the zero-point energy (ZPE) corrections as well as to conrm the minima character of the obtained geometries at the same level of theory (i.e. the local minimal with positive frequencies and saddle points with only one imaginary frequency).…”

Section: Methodsmentioning

confidence: 99%

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

et al. 2018

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Section: Methodsmentioning

confidence: 99%

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

et al. 2018

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“…The quantum mechanical tunneling correction (Γ, dimensionless) was calculated using Eckart's method. [46][47][48] The entropy differences between the reactants and the transition states (ΔS ≠ ) over the temperature range of 200-3000 K were used to determine the preexponential factor (A, s −1 or cm 3 mol −1 s −1 ). The preexponential values of A are expressed by…”

Section: Calculation Methodsmentioning

confidence: 99%

Reaction kinetics and thermochemistry of the chemically activated and stabilized primary ethyl radical of methyl ethyl sulfide, CH₃SCH₂CH₂•, with O₂ to CH₃SCH₂CH₂OO•

Song

Bozzelli

2019

Int J of Chemical Kinetics

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Oxidation of methyl ethyl sulfide (CH 3 SCH 2 CH 3 , methylthioethane, MES) under atmospheric and combustion conditions is initiated by hydroxyl radicals, MES radicals, generated after loss of a H atom via OH abstraction, will further react with O 2 to form chemically activated and stabilized peroxyl radical adducts. The kinetics of the chemically activated reaction between the CH 3 SCH 2 CH 2 • radical and molecular oxygen are analyzed using quantum Rice-Ramsperger-Kassel theory for k(E) with master equation analysis and a modified strong-collision approach to account for further reactions and collisional deactivation. Thermodynamic properties of reactants, products, and transition states are determined by the B3LYP/6-31+G(2d,p), M062X/6-311+G(2d,p), B97XD/6-311+G(2d,p) density functional theory, and CBS-QB3, G3MP2B3, and G4 composite methods. The reaction of CH 3 SCH 2 CH 2 • with O 2 forms an energized peroxy adduct CH 3 SCH 2 CH 2 OO• with a calculated well depth of 34.1 kcal mol −1 at the CBS-QB3 level of theory. Thermochemical properties of reactants, transition states, and products obtained under CBS-QB3 level are used for calculation of kinetic parameters. Reaction enthalpies are compared between the methods. The temperature and pressure-dependent rate coefficients for both the chemically activated reactions of the energized adduct and the thermally activated reactions of the stabilized adducts are presented. Stabilization and isomerization of the CH 3 SCH 2 CH 2 OO• adduct are important under high pressure and low temperature.At higher temperatures and atmospheric pressure, the chemically activated peroxy adduct reacts to new products before stabilization. Addition of the peroxyl oxygen radical to the sulfur atom followed by sulfur-oxygen double bond formation and elimination of the methyl radical to form S(= O)CCO• + CH 3 (branching) is a potentially important new pathway for other alkyl-sulfide peroxy radical systems under thermal or combustion conditions. K E Y W O R D Skinetics, methyl ethyl sulfide, oxidation, thermochemistry 618

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“…In the present work, all the reactants (R), transition states (TS), intermediates (IM), and products (P) were optimized by the hybrid meta exchange-correlation functional M06-2X [28] in conjunction with the 6-311 + G(d,p) basis set. The choice of M06-2X was based on the previous computational studies on methoxyphenols [29][30][31] and the M06-2X has been often recommended because of its accurate results such as thermochemical and kinetic data [32][33][34]. Harmonic frequency analyses were calculated at the same level to distinguish initial conformation obtained whether they were true minimum or firstorder saddle points.…”

Section: Computation Detailsmentioning

confidence: 99%

Atmospheric oxidation of 4‐(2‐methoxyethyl) phenol initiated by OH radical in the presence of O₂ and NO_x: A mechanistic and kinetic study

Yao

Sun

Tang

et al. 2021

Int J of Quantum Chemistry

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4-(2-Methoxyethyl) phenol (MEP) plays an important role in the formation of secondary organic aerosols (SOA). The gas-phase mechanism and kinetics of MEP with OH reaction are studied by the density functional theory (DFT). The initial reactions of MEP with OH radical produce two different channels: OH addition and H abstraction. Subsequent reaction schemes of the main intermediates are investigated by using M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. Ketene, diketones and nitrophenol compounds are demonstrated to be the dominant oxidation products in the presence of high O 2 and NO x . The total and individual rate constants are calculated by using the traditional transition state theory (TST) at 298K and 1atm.The calculated value of 5.62×10 −11 cm 3 molecule −1 s −1 is close to experimental data of similar systems. The lifetime of MEP is estimated to be 4.94 hours. These results provide a comprehensive explanation for atmospheric oxidation pathways of MEP.

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Theoretical studies on the mechanism and kinetics of the hydrogen abstraction reactions of threo -CF 3 CHFCHFC 2 F 5 and erythro-CF 3 CHFCHFC 2 F 5 (HFC-43-10mee) by OH radicals

Cited by 8 publications

References 19 publications

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

Reaction kinetics and thermochemistry of the chemically activated and stabilized primary ethyl radical of methyl ethyl sulfide, CH₃SCH₂CH₂•, with O₂ to CH₃SCH₂CH₂OO•

Atmospheric oxidation of 4‐(2‐methoxyethyl) phenol initiated by OH radical in the presence of O₂ and NO_x: A mechanistic and kinetic study

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Theoretical studies on the mechanism and kinetics of the hydrogen abstraction reactions of threo -CF 3 CHFCHFC 2 F 5 and erythro-CF 3 CHFCHFC 2 F 5 (HFC-43-10mee) by OH radicals

Cited by 8 publications

References 19 publications

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

Theoretical study of the oxidation reactions of sulfurous acid/sulfite with ozone to produce sulfuric acid/sulfate with atmospheric implications

Reaction kinetics and thermochemistry of the chemically activated and stabilized primary ethyl radical of methyl ethyl sulfide, CH3SCH2CH2•, with O2 to CH3SCH2CH2OO•

Atmospheric oxidation of 4‐(2‐methoxyethyl) phenol initiated by OH radical in the presence of O2 and NOx: A mechanistic and kinetic study

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Reaction kinetics and thermochemistry of the chemically activated and stabilized primary ethyl radical of methyl ethyl sulfide, CH₃SCH₂CH₂•, with O₂ to CH₃SCH₂CH₂OO•

Atmospheric oxidation of 4‐(2‐methoxyethyl) phenol initiated by OH radical in the presence of O₂ and NO_x: A mechanistic and kinetic study