A theoretical investigation on the kinetics and reactivity of the gas-phase reactions of ethyl chlorodifluoroacetate with OH radical and Cl atom at 298 K

Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation

“…Mishra et al 24 have calculated the rate coefficient for H-atom abstraction from CF 2 ClC(O)OCH 3 by Cl atoms using canonical transition state theory (CTST) and employing Wigner 25 and Eckart 26 symmetrical methods which gave values of 0.96 Â 10 À13 and 1.20 Â 10 À13 cm 3 per molecule per s, respectively, at 298 K for the reaction. These values are in very good agreement with the experimental value of 0.98 Â 10 À13 cm 3 per molecule per s reported in this work and the previous experimental value reported by our group, using a different experimental setup, of (1.0 AE 0.2) Â 10 À13 cm 3 per molecule per s. 19 In another study Mishra et al 27 OCHCH 3 + HCl, respectively. Mishra et al 27 reported a value of 1.86 Â 10 À12 cm 3 per molecule per s for the overall rate coefficient of the reaction (i.e.…”

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

“…The temperature dependence of the branching ratios k 1 / k T(1) and k 2 / k T(1) are plotted in Figure 4. It is clear from Figure 4 that H‐abstraction from the CH 2 group is the main reaction channel in the temperature range 200–1000 K, similar to the branching ratios of the reactions of CF 2 ClCOOCH 2 CH 3 with Cl and OH radicals 17. The contributions of the CH 2 site to the H‐abstraction reaction are 99.8 % and 97.9 % for the Cl and OH radicals at 298 K, respectively.…”

“…A positive temperature dependence effect can be found in the dynamic results of all the reactions (R1–R7), which also appears in other similar ester reactions with Cl atoms and OH radicals 10. 17–21 From Table 3, the values of ${k^{CVT/SCT} }$ for the reaction CF 3 COOCH 3 +Cl are larger than those determined for the reaction CF 3 COOCH 3 +OH in the temperature range of 200–1000 K. Hence, the H‐abstraction reaction with a Cl atom is a more important degradation channel for CF 3 COOCH 3 than that with an OH radical. This phenomenon was also found in other experimental and theoretical investigations on the reaction of esters with OH radicals and Cl atoms 10–12.…”

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

“…Therefore, it is necessary to understand the chemistry of fluorinated esters in the atmosphere in order to assess the environmental acceptability of HFEs as a plausible replacement for chlorofluorocarbons. The reaction mechanisms of FESs with atmospheric oxidants have been studied extensively both experimentally [20][21][22][23][24][25] and theoretically [26][27][28][29][30][31][32] and continue to receive considerable attention. FESs absorb strongly in the earthly infrared (IR) radiation region of 800-1,200 cm −1 .…”