Asunto(s)
Compuestos de Anilina , Herbicidas , Hongos Mitospóricos/metabolismo , Suelo/análisis , Compuestos de Anilina/análisis , Compuestos de Anilina/metabolismo , Butanoles/análisis , Radioisótopos de Carbono , Remoción de Radical Alquila , Estabilidad de Medicamentos , Contaminación Ambiental , Herbicidas/análisis , Herbicidas/metabolismo , Nitrocompuestos/análisis , Nitrocompuestos/metabolismo , Oxidación-Reducción , Residuos de Plaguicidas/análisis , Microbiología del Suelo , EstereoisomerismoRESUMEN
Dimeric products are formed by riboflavin-sensitized photooxidation of 2,4-dichlorophenol. The products of this reaction were examined to determine whether chlorinated dibenzo-p-dioxins could be formed from chlorophenols in water by the action of light of wavelengths greater than 280 nanometers. Dimers are formed by union of phenoxy radicals through carbon-carbon or carbon-oxygen bonds. 4,6-Dichloro-2-(2,4-dichlorophenoxy) phenol was obtained in greater quantity than other dimers. Products were characterized by combined gas chromatography and mass spectrometry. Chlorinated dibenzo-p-dioxins which could result from ring closure of a 2-phenoxyphenol derivative were not detected in the products of photolysis. The failure to detect chlorinated dibenzo-p-dioxins may result from the rapid photolytic breakdown of the lower chlorinated dibenzop-dioxins. Under environmental conditions, dioxins are unlikely products of the lower chlorinated phenols or phenoxyalkanoic acids.
Asunto(s)
Dioxinas/síntesis química , Herbicidas , Fenoles , Fotoquímica , Riboflavina , Ácido 2,4-Diclorofenoxiacético , Cromatografía en Capa Delgada , Dioxinas/análisis , Oxidación-Reducción , Fotólisis , Análisis EspectralRESUMEN
The pesticide DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane] and its metabolite DDE [ 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene] can be photoOxidized in methanol. Photolytic generation of free radicals that may abstract hydrogen from solvent, react with oxygen, or abstract hydrogen from unreacted substrate occurs. Further decomposition of short-lived intermediates yields many compounds. Oxidation products include benzoic acids, aromatic ketones, and chlorinated phenols. The DDE also undergoes photocyclization to give dichlorofluorene derivatives.