Computational kinetic study on atmospheric oxidation reaction mechanism of 1-fluoro-2-methoxypropane with OH and ClO radicals

Abstract

The knowledge of atmospheric chemistry has explained several reactions that occur in atmosphere regarding volatile organic compounds (VOCs). In this original paper, computational kinetic study was carried out on atmospheric oxidation reaction mechanism of 1-fluoro-2-methoxypropane (CH3CH(OCH3)CFH2) with OH/ClO radicals using DFT/M06-2X/6–311++G∗∗ method. To improve the results, DFT/M06-2X/6–311++G(2df,2p) single-point calculations were performed on the reacting species involved. The Monte Carlo search on the investigating hydrofluoroether (H3CCH(OCH3)CFH2) showed nine conformers with the lowest global minimum conformer being considered for this study. The reaction proceeded via four (4) reaction routes which led to dehydrogenation in each cases of the radical (OH/ClO) used. The total rate for dehydrogenation reaction of H3CCH(OCH3)CFH2 with OH/ClO radicals is 9.13 ∗ 103 s−1 and 1.23 ∗ 106 s−1 at 298 K which is in agreement with the available experimental rates recorded by Healthfield et al. (1998), Kazuaki Tokuhashi et al. (2000). Also, in each radical cases, thermodynamics parameters, the major and minor products’ heat of formation were computed with potential energy surfaces (PES) for the reactions constructed at absolute temperature of 298 K. Keywords: 1-fluoro-2-methoxypropane, Density functional theory, Ozone depletion, Hydrofluoroethers (HFEs), OH & ClO radicals