Theoretical studies on mechanism and kinetics of the hydrogen-abstraction reaction of CF2HCOOCH3 with OH radicals

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

“…The good agreement with the previous work indicates that our prediction of branching ratios and temperature dependencies of the title reactions is reliable. 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.…”

“…Accurate knowledge of the standard enthalpies of formation is important for understanding the kinetic of atmospheric processes and thermodynamic properties of these species. Because of the enthalpies of formation of CF 2 HCOOCH 3 , CF 2 COOCH 3 and CF 2 HCOOCH 2 were calculated by Zhu et al10 at the MCG3–MPWB//M06‐2X/aug–cc–pVDZ level. Only the standard enthalpies of formation of the reactants CF 3 COOCH 2 CH 3 , CF 3 COOCH 3 and product radicals CF 3 COOCHCH 3 , CF 3 COOCH 2 CH 2 , CF 3 COOCH 2 are predicted using the following isodesmic reactions:, , , , , , , , , , , , , , …”

“…FESs, which contain carbon–hydrogen bonds, can be oxidized in the atmosphere by highly reactive radicals such as Cl and OH radicals 10. The chlorine atom is an important reactive intermediate in combustion and atmosphere, which has a strong ability of oxidation 25.…”

“…With regard to methyl difluoracetate (CF 2 HCOOCH 3 ), there are two stable conformers, defined as conformer I with C 1 symmetry and conformer II with C s symmetry (see Figure S1 in the Supporting Information, SI). Zhu et al10 have investigated the theoretical mechanism and dynamics of methyl difluoracetate with the OH radical. The energy difference of conformers I and II (0.48 kcal mol −1 in their paper) is similar to our calculated energy difference (0.43 kcal mol −1 ) at the CCSD(T)/6‐311++G(d,p)//B3LYP/6‐311G(d,p) level.…”

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 .…”