Photodecomposition of p-chlorophenoxyacetic acid

Abstract

This research was supported in part by funds provided by the Food and Drug Administration DHEW under contract FDA 71-285 and the Michigan Agricultural Experiment Station, Article No. 6424. This research was presented in part at the 160th National Meeting of the American Chemical Society, Chicago, 111., Sept 1970.

Review: Environmental chemistry: An overview

“…However, without the synthesis chemist's high temperatures and concentrations, and with very different catalysts if any, nature's reagents and processes necessarily look quite different. The ultraviolet region of sunlight replaces heat (a wavelength of 300 nm corresponds to 95.3 kcal/mol), the aromatic ring selectively absorbs the energy, and chloride ions are readily displaced from the excited molecule at normal temperatures by even M hydroxide ion (pH 8) [22]. Hydroxyl radicals replace the much less reactive triplet oxygen, and atmospheric oxidation of methane proceeds to carbon monoxide and hydrogen via formaldehyde rather than the other way around [23].…”

Photodecomposition of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in water

“…The rate of 2,4,5-T photolysis was somewhat more rapid at p H 8 than at p H 3 and was very slow compared to those of 4-CPA and 2,4-D ( Figure 3). However, the photolysis rate of 2,4,5-trichlorophenol under the same conditions was rapid, and side chain oxidation (Crosby and Wong, 1973) was the ratelimiting step in 2,4,5-T photodecomposition. However, the photolysis rate of 2,4,5-trichlorophenol under the same conditions was rapid, and side chain oxidation (Crosby and Wong, 1973) was the ratelimiting step in 2,4,5-T photodecomposition.…”

Photoreduction of the Chloropropionic Acid of Carfentrazone-Ethyl in Sodium Sulfide Crane Flat Meadow Solutions

“…Previously, our laboratory reported chloroaromatic and nitroaromatic photoreductions in filtered rice field water [5][6][7], and photodechlorinations of mirex in aqueous humic acid [8] and of DDE (2,2-bis[4-chlorophenyl]-1,1-dichloroethylene) in resuspended sediment solutions [9] were reported to be suggestive of a photochemical reaction with reduced organic matter. Natural matrix use, however, precludes identifying the e Ϫdonating structures, whereas photodechlorinations using known reductants were run in organic solvent systems [10][11][12][13][14][15] that are inapplicable to natural waters.…”