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Rate coefficient for the reaction of CCl 3 radicals with ozone
Author(s) -
Imamura Takashi,
Chono Hideharu,
Shibuya Kazuhiko,
Washida Nobuaki
Publication year - 2003
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.10130
Subject(s) - chemistry , ozone , radical , photoionization , carbon tetrachloride , reaction rate , photodissociation , analytical chemistry (journal) , photochemistry , reaction rate constant , kinetics , organic chemistry , catalysis , ionization , ion , physics , quantum mechanics
The rate coefficient for the reaction of CCl 3 radicals with ozone has been measured at 303 ± 2 K. The CCl 3 radicals were generated by the pulsed laser photolysis of carbon tetrachloride at 193 nm. The time profile of CCl 3 concentration was monitored with a photoionization mass spectrometer. Addition of the O 3 –O 2 mixture to this system caused a decay of the CCl 3 concentration because of the reactions of CCl 3 + O 3 → products (5) and CCl 3 + O 2 → products (4). The decay of signals from the CCl 3 radical was measured in the presence and absence of ozone. In the absence of ozone, the O 3 –O 2 mixture was passed through a heated quartz tube to convert the ozone to molecular oxygen. Since the rate coefficient for the reaction of CCl 3 + O 2 could be determined separately, the absolute rate coefficient for reaction (5) was obtained from the competition among these reactions. The rate coefficient determined for reaction (5) was (8.6 ± 0.5) × 10 −13 cm 3 molecule −1 s −1 and was also found to be independent of the total pressure (253–880 Pa of N 2 ). This result shows that the reaction of CCl 3 with O 3 cannot compete with its reaction with O 2 in the ozone layer. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 310–316, 2003