A theoretical investigation on the kinetics, mechanism and thermochemistry of gas-phase reactions of methyl acetate with chlorine atoms at 298 K

Deka, Ramesh Chandra; Mishra, Bhupesh Kumar

doi:10.1016/j.cplett.2014.01.049

Cited by 21 publications

(12 citation statements)

References 35 publications

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“…This phenomenon was also found in other experimental and theoretical investigations on the reaction of esters with OH radicals and Cl atoms 10–12. 14–16, 18, 20, 21…”

Section: Resultssupporting

confidence: 80%

Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH

et al. 2015

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The mechanism and kinetics of the reactions of CF(3)COOCH(2)CH(3), CF(2)HCOOCH(3), and CF(3)COOCH(3) with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06-2X methods with the 6-311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6-311++G(d,p) methods. Seven hydrogen-abstraction channels are found. All the rate constants, computed by a dual-level direct method with a small-curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low-temperature range. For the reaction of CF(3)COOCH(2)CH(3) +Cl, H-abstraction from the CH(2) group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200-1000 K as kT(1) =8.4×10(-20) T (2.63) exp(381.28/T), kT(2) =2.95×10(-21) T (3.13) exp(-103.21/T), kT(3) =1.25×10(-23) T (3.37) exp(791.98/T), and kT(4) =4.53×10(-22) T (3.07) exp(465.00/T).

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“…This phenomenon was also found in other experimental and theoretical investigations on the reaction of esters with OH radicals and Cl atoms 10–12. 14–16, 18, 20, 21…”

Section: Resultssupporting

confidence: 80%

Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH

et al. 2015

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“…The ZPE thus obtained was corrected with a scale factor of 0.951 to partly eliminate systematic errors [34]. This dual level calculation [G2(MP2)//MPWB1K/6-31+G(d,p)] is known to produce reliable thermochemical and kinetic data [28,[41][42][43][44]. All quantum mechanical calculations were performed with the Gaussian 09 suite of programs [45].…”

Section: Methodsmentioning

confidence: 99%

Theoretical investigation on mechanism and kinetics of the Cl-initiated hydrogen abstraction reactions of ethyl trifluoroacetate at 298 K

2014

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Theoretical investigations were carried out on the gas-phase reactions of CF3C(O)OCH2CH3, ethyl trifluoroacetate (ETFA) with Cl atoms by means of modern density functional theory methods. The optimized geometries, frequencies and minimum energy path were obtained with the hybrid density functional model MPWB1K using the 6-31+G(d,p) basis set. The single point energy calculations were refined further using the G2(MP2) method. Two conformers relatively close in energy were identified for ETFA; both are likely to be important in the temperature range of our study. The existence of transition states on the corresponding potential energy surface was ascertained by performing intrinsic reaction coordinate calculations. The rate constant at 298 K calculated theoretically using canonical transition state theory was found to be in good agreement with experimentally measured values. Our calculations suggest that H abstraction from the -CH2 group is kinetically and thermodynamically more favorable than abstraction from the -CH3 group. The atmospheric lifetime of ETFA with Cl atoms was determined to be 1.98 years. To the best of our knowledge, this work represents the first determination of the rate coefficients for the gas-phase reaction of chlorine atoms in ETFA.

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“…The interaction between atomic chlorine or OH radical with organic molecules present in the atmosphere needs a detailed understanding as it might help in controlling the ozone depletion. The interaction of oxygen bases with atomic chlorine has been investigated in several works, for example the interaction of Cl • with H 2 O [1,2], halogenated ethers [3][4][5][6][7], methylacetate [8], halogenated aldehydes [9], fluorinated alcohols [10] and halogenated alkanes [11]. For most of these systems, such as the H 2 O. .…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of the interaction between pyridine derivatives and atomic chlorine. Substituent effect and nature of the bonding

2015

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The interaction of pyridine derivatives (H, ) with atomic chlorine is investigated theoretically by the density functional theory (DFT)-based LC-BLYP/aug-cc-pVDZ method. Pyridines and Cl • are held together by a (2c-3e) bond and the intermolecular distances range from 2.313 to 2.343Å. The existence of a N. . .Cl bond is confirmed by the atom-in-molecule analysis of the systems. The binding energies of the adducts, ranging from −42.08 to −53.96 kJ mol −1 , are linearly correlated to the proton affinity of the pyridines. The charge transfer from pyridine to Cl • varies between 0.222 and 0.277 e. The spin density analysis shows that the strongest complex has the highest (2c-3e) character. The CH bonds are contracted and the ν(CH) vibrations are blueshifted owing to the decrease in σ * (CH) occupation. This decrease results not only from the classical anomeric effect but also from the σ (CC) and σ (CN) → σ * (CH) delocalisation in the heteroaromatic ring.

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A theoretical investigation on the kinetics, mechanism and thermochemistry of gas-phase reactions of methyl acetate with chlorine atoms at 298 K

Cited by 21 publications

References 35 publications

Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH

Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH

Theoretical investigation on mechanism and kinetics of the Cl-initiated hydrogen abstraction reactions of ethyl trifluoroacetate at 298 K

Theoretical study of the interaction between pyridine derivatives and atomic chlorine. Substituent effect and nature of the bonding

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A theoretical investigation on the kinetics, mechanism and thermochemistry of gas-phase reactions of methyl acetate with chlorine atoms at 298 K

Cited by 21 publications

References 35 publications

Theoretical Studies of the Reactions CFxH3−xCOOR+Cl and CF3COOCH3+OH

Theoretical Studies of the Reactions CFxH3−xCOOR+Cl and CF3COOCH3+OH

Theoretical investigation on mechanism and kinetics of the Cl-initiated hydrogen abstraction reactions of ethyl trifluoroacetate at 298 K

Theoretical study of the interaction between pyridine derivatives and atomic chlorine. Substituent effect and nature of the bonding

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Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH

Theoretical Studies of the Reactions CF_xH_3−xCOOR+Cl and CF₃COOCH₃+OH