Atmospheric Photooxidation of Fluoroacetates as a Source of Fluorocarboxylic Acids

M. B. BLANCO, I. BEJAN, I. BARNES, P. WIESEN AND MARIANO A. TERUEL

AMER CHEMICAL SOC

Año: 2010 vol. 44 p. 2354 - 2354

1080 L environmental chamber with in situ FTIR spectroscopy detection was used to study the product distribution and the mechanism of the Cl-initiated photooxidation of a series of fluoroacetates. The gas-phase reactions of Cl atoms with ethyl trifluoroacetate (CF3C(O)OCH2CH3), methyl trifluoroacetate (CF3C(O)OCH3), and methyl difluoroacetate (CF2HC(O)OCH3) were investigated at 296(2 K and atmospheric pressure (∼760 Torr) of synthetic air. The fate of the fluoroalkoxy radicals formed in the reaction with Cl atoms mainly occurs through (i) an H-atom abstraction by reaction with O2, to produce the corresponding fluoroanhydride and (ii) anR-ester rearrangement via a five-membered ring intermediate to give the corresponding fluoroacetic acid. The yields of fluoroacids (CF2XC(O)OH, with X ) H, F) obtained were as follows: 78 ( 5, 23 ( 2, and 30(5%for CF3C(O)OCH2CH3,CF3C(O)OCH3, and CF2HC(O)OCH3,, respectively. Yields ofe20,e80, ande55% have been estimated for the anh