Theoretical studies on atmospheric chemistry of HFE-347mcc3: reactions with OH radicals and Cl atoms

Abstract

Detailed theoretical investigation has been performed on the mechanism, kinetics and thermochemistry of the gas phase reactions of CF 3 CF 2 CF 2 OCH 3 (HFE-347mcc3) with OH radicals and Cl atoms using M06-2X/6-31 + G(d,p) level of theory. Reaction profiles are modeled including the formation of pre-reactive and post-reactive complexes at entrance and exit channels, respectively. Using group-balanced isodesmic reactions, the standard enthalpies of formation for species are also reported. The calculated bond dissociation energy for C-H bond is in good agreement with previous data. The rate constants of the two reactions are determined for the first time in a wide temperature range of 250-1000 K. At 298 K, the calculated rate coefficients are in good agreement with the experimental results. The atmospheric life time of HFE-347mcc3 is estimated to be 4.4 years.

A theoretical insight into atmospheric chemistry of HFE-7100 and perfluoro-butyl formate: reactions with OH radicals and Cl atoms and the fate of alkoxy radicals

“…This method was widely used in the past to study hydrogen abstraction reactions yielding reliable results for mechanism development and rate constant calculations. [17][18][19][20][21][22][23][24][25] For normal-mode analysis, vibrational frequency calculations were performed to determine the nature of species. Connections of the transition states between designated reactants and products have been confirmed by intrinsic reaction coordinate (IRC) calculations 26 carried out at the M06-2X/6-31+G(d,p) level.…”

Theoretical studies on the hydrogen abstraction reactions of methyl esters with HO2radical and the following β-scission reactions

“…Further, the following β‐scission reactions of the forming methyl ester radicals via abstraction reactions play a critical role in the description of high‐temperature combustion processes because the products from the β‐scission reactions completely determine the combustion characteristics of the fuels . Although a series of theoretical studies were performed for hydrogen abstraction reactions through radical mechanism for typical compounds and thermal decomposition reactions of saturated methyl esters, little attention has been focused on the effect of the C = C double bond on the elementary abstraction reactions of methyl esters. Moreover, the following β‐scission reactions of the forming radicals are also not considered in previous theoretical studies.…”