Combustion Research Facility, Mail Stop 9055 , Sandia National Laboratories, Livermore , California 94551-0969 United States.
School of Chemistry , The University of Bristol , Cantock's Close BS8 1TS , Bristol , U.K.
Environ Sci Technol. 2019 Feb 5;53(3):1245-1251. doi: 10.1021/acs.est.8b05073. Epub 2019 Jan 11.
The reaction of perfluorooctanoic acid with the smallest carbonyl oxide Criegee intermediate, CHOO, has been measured and is very rapid, with a rate coefficient of (4.9 ± 0.8) × 10 cm s, similar to that for reactions of Criegee intermediates with other organic acids. Evidence is shown for the formation of hydroperoxymethyl perfluorooctanoate as a product. With such a large rate coefficient, reaction with Criegee intermediates can be a substantial contributor to atmospheric removal of perfluorocarboxylic acids. However, the atmospheric fates of the ester product largely regenerate the initial acid reactant. Wet deposition regenerates the perfluorocarboxylic acid via condensed-phase hydrolysis. Gas-phase reaction with OH is expected principally to result in formation of the acid anhydride, which also hydrolyzes to regenerate the acid, although a minor channel could lead to destruction of the perfluorinated backbone.
全氟辛酸与最小的羰基氧化物 Criegee 中间体 CHOO 的反应已经被测量过，其反应速度非常快，速率系数为(4.9 ± 0.8)×10^-13 cm^3 s^-1，与 Criegee 中间体与其他有机酸的反应速率系数相似。有证据表明，产物为过氧甲基全氟辛酸酯。由于如此大的速率系数，与 Criegee 中间体的反应可能是大气中全氟羧酸去除的一个重要贡献者。然而，酯产物的大气命运在很大程度上再生了初始酸反应物。湿沉降通过凝聚相水解将全氟羧酸再生。与 OH 的气相反应预计主要导致酸酐的形成，酸酐也会水解再生酸，尽管一个次要的途径可能导致全氟化主链的破坏。
