Atmospheric chemistry of 1,4-dioxane Laboratory studies
| Autor: | J. Platz, Timothy J. Wallington, Ole John Nielsen, Trine E. Møgelberg, Jens Sehested |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Journal of the Chemical Society, Faraday Transactions. 93:2855-2863 |
| ISSN: | 1364-5455 0956-5000 |
| DOI: | 10.1039/a700598i |
| Popis: | A pulse radiolysis technique was used to measure the UV absorption spectra of c-C 4 H 7 O 2 and (c-C 4 H 7 O 2 )O 2 radicals over the range 220–320 nm, σ(c-C 4 H 7 O 2 ) 250nm = (5.9 ± 0.6) × 10 −18 and σ[(c-C 4 H 7 O 2 )O 2 ] 240nm = (4.8 ± 0.8) × 10 −18 cm 2 molecule −1 . The observed self-reaction rate constants for the c-C 4 H 7 O 2 and (c-C 4 H 7 O 2 )O 2 radicals, defined as −d[c-C 4 H 7 O 2 ]/dt = 2k 4 [c- C 4 H 7 O 2 ] 2 and −d[(c-C 4 H 7 O 2 )O 2 ]/dt = 2k 5obs [(c-C 4 H 7 O 2 )O 2 ] 2 were k 4 = (3.3 ± 0.4) × 10 −11 and k 5obs = (7.3 ± 1.2) × 10 −1 2 cm 3 molecule −1 s −1 . The rate constants for reactions of (c-C 4 H 7 O 2 )O 2 radicals with NO and NO 2 were k 6 (1.2 ± 0.3) × 10 −11 and k 7 = (1.3 ± 0.3) × 10 −11 cm 3 molecule −1 s −1 , respectively. The rate constants for the reaction of F atoms with 1,4-dioxane and the reaction of c-C 4 H 7 O 2 radicals with O 2 , were k 3 = (2.4 ± 0.7) × 10 −10 and k 2 = (8.8 ± 0.9) × 10 −12 cm 3 molecule −1 s −1 , respectively. A relative rate technique was used to measure the rate constant for the reaction of Cl atoms with 1,4-dioxane, k 17 = (2.0 ± 0.3) × 10 −10 cm 3 molecule −1 s −1 . A long-pathlength FTIR spectrometer coupled to a smog chamber system was used to show that the sole atmospheric fate of the alkoxy radical (c-C 4 H 7 O 2 )O is decomposition via C–C bond scission leading to the formation of H(O)COCH 2 CH 2 OC(O)H (ethylene glycol diformate). |
| Databáze: | OpenAIRE |
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