Henryʹs law constants and hydrolysis rate constants of 2,2,2-trifluoroethyl acetate and methyl trifluoroacetate

Henryʹs law constants (H) and hydrolysis rate constants (kh) of two fluorinated esters [CH3C(O)OCH2CF3 and CF3C(O)OCH3] were determined at 278–298 K by a column-stripping method. The H value at 298 K (H298) and the standard solvation enthalpy for gas-to-liquid transfer (ΔHsol) were determined from the van’t Hoff equation to be H298=0.58±0.04 M atm−1 and ΔHsol=−44±3 kJ mol−1 for CH3C(O)OCH2CF3, and H298=0.12±0.04 M atm−1 and ΔHsol=−41±16 kJ mol−1for CF3C(O)OCH3. Hydrolysis of CH3C(O)OCH2CF3 was not observed(kh<7×10−5 s−1), whereas the kh value of CF3C(O)OCH3 was determined to be 105.3±2.0exp{−(5.07±1.27)×103/T} s−1. The effects of pH and metal ions, and the salting-out effects of NaCl were also examined for CH3C(O)OCH2CF3. Dissolution in seawater is expected to be a significant tropospheric sink of these fluorinated esters.