Abstract
In order to estimate the kinetics of reaction between OH radical (kOH) and fluorinated formates, which are primary products from the oxidation of hydrofluoroethers (HFEs), the C-H bond dissociation enthalpies (BDE) for fluorinated formates were calculated by using density functional theory (DFT). B3LYP exchange correlation function and 6-311G(d,p) basis set were used to estimate BDE for CnF2n+1OC(O)H: (n=2-4) and CnHF2nOC(O)H: (n=1-3). Since the experimentally measured activation energy (Eact) of the hydrogen abstraction by OH radical for fluorinated formates has never been reported, we estimated the relation between BDE and Eact from the computed values, which had been calculated by using G2(MP2), for syn and anti isomers of CF3OC(O)H. Furthermore, computed Arrhenius A-factor of CF3OC(O)H was adopted to other all formates because lower level calculations with UHF/6-311G(d,p) was revealed that Arrhenius A-factors did not depend on the chain length of formates. Finally, kOH and the life time concerning with decomposition by OH radical (tOH) were estimated with using Arrhenius A-factor and Eact, which were evaluated using BDE, for ten fluorinated formates.
