Detail of "1574-41-0"

Reference

Quantum yields for reaction of pollutants in dilute aqueous solution

Quantum yields for reaction of pollutants in dilute aqueous solution. Zepp, Richard G. (Environ. Res. Lab., EPA, Athens, Ga., USA). Environ. Sci. Technol., 12(3), 327-9 (English) 1978. CODEN: ESTHAG. ISSN: 0013-936X. DOCUMENT TYPE: Journal CA Section: 61 (Water) Section cross-reference(s): 74 Quantum yields were detd. for direct photolysis of pollutants at low concns. in water and used to compute half-lives for direct photolysis of aquatic pollutants under sunlight. The av. cell pathlength for quantum yield was detd. by using benzophenone-sensitized photoisomerization of cis-1,3-pentadiene [1574-41-0]. Direct photolysis half life of carbaryl [63-25-2] in water was calcd. at midday, midsummer, and latitude 40°N.

Photosensitized transformations involving electronic energy transfer in natural waters: role of humic substances

Photosensitized transformations involving electronic energy transfer in natural waters: role of humic substances. Zepp, Richard G.; Schlotzhauer, Patricia F.; Sink, R. Merritt (Environ. Res. Lab., Environ. Prot. Agency, Athens, GA 30613, USA). Environ. Sci. Technol., 19(1), 48-55 (English) 1985. CODEN: ESTHAG. ISSN: 0013-936X. DOCUMENT TYPE: Journal CA Section: 61 (Water) Section cross-reference(s): 22, 74 Studies are reported of the kinetics of photosensitized reactions involving the transfer of absorbed light energy from humic substances to various trace org. chems. in water. The photoisomerization of cis-1,3-pentadiene (I) [1574-41-0] and the photooxidn. of 2,5-dimethylfuran (II) [625-86-5] were used to probe the nature and concns. of the excited species that mediate humus-sensitized photoreactions of aquatic pollutants. Evidence is presented that the photosensitized reactions of I and II do not involve binding of the chems. by the humic substances. Kinetic results indicate that the key steps in both photoreactions involve the transfer of electronic energy from triplet states of the humic substances. Up to half of these triplets are estd. to have energies of 3250 kJ/mol, sufficiently high to transfer energy to polycyclic arom. hydrocarbons, nitroarom. compds., conjugated dienes, and other types of chems. Steady-state concns. of the humus-derived triplets are estd. to typically fall in the 10-15-10-13 M range in the upper layers of sunlight-irradiated natural waters. The concns. are proportional to the UV absorption coeffs. of the water. Action spectra for the photosensitized reactions indicate that solar UV radiation is most important in inducing the reactions. The results of the study are used to est. max. rates of reactions photosensitized by humic substances.