Atmospheric degradation of fluoroesters (FESs): Gas-phase reactivity study towards OH radicals at 298 K

Using the relative technique, rate coefficients have been measured for the gas phase reactions of hydroxyl radicals with four fluoroacetates, methyl trifluoroacetate (CF₃COOCH₃), ethyl trifluoroacetate (CF₃COOCH₂CH₃), methyl difluoroacetate (CF₂HCOOCH₃) and 2,2,2-trifluoroethyl trifluoroacetate (CF₃COOCH₂CF₃). Experiments were carried out at 296±2 K and atmospheric pressure (～750 Torr) using nitrogen or synthetic air as bath gases. The following rate coefficients were derived for the reaction of OH radicals (in units of cm³ mol^?1 s^?1) with CF₃COOCH₃, k=(4.97±1.04)×10^?14, CF₃COOCH₂CH₃, k=(2.64±0.59)×10^?13, CF₂HCOOCH₃, k=(1.48±0.34)×10^?13 and CF₃COOCH₂CF₃, (1.05±0.23)×10^?13. The rate constants obtained are compared with previous literature data of other volatile organic compounds to establish reactivity trends. Atmospheric implications are discussed in terms of lifetimes and fates of the fluoroacetates in the troposphere.