Rate coefficient for the reaction of CCl3 radicals with ozone
Rate coefficient for the reaction of CCl3 radicals with ozone
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DOI：
10.1002/kin.10130
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发表时间：
2003
影响因子：
1.5
通讯作者：
T. Imamura;Hideharu Chono;K. Shibuya;N. Washida
中科院分区：
文献类型：
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作者：
T. Imamura;Hideharu Chono;K. Shibuya;N. Washida
在303 ± 2K下测定了CCl_3自由基与臭氧反应的速率系数。CCl 3自由基是由四氯化碳在193 nm处的脉冲激光光解产生的。用光电离质谱仪监测CCl 3浓度的时间曲线。向该体系中加入O3-O2混合物导致CCl 3浓度的衰减，因为CCl 3 + O3产物（5）和CCl 3 + O2产物（4）反应。在存在和不存在臭氧的情况下，从四氯化碳自由基的信号的衰减进行了测量。在不存在臭氧的情况下，使O3-O2混合物通过加热的石英管以将臭氧转化为分子氧。由于CCl 3 + O2反应的速率系数可以单独确定，因此反应（5）的绝对速率系数是从这些反应之间的竞争中获得的。反应（5）的速率系数为（8.6 ± 0.5）× 10−13 cm 3 molecule−1 s−1，并且与总压（253-880 Pa N2）无关。这一结果表明，在臭氧层中，CCl 3与O3的反应不能与其与O2的反应竞争。© 2003 Wiley Periodicals，Inc. Int J Chem Kinet 35：310-316，2003
The rate coefficient for the reaction of CCl3 radicals with ozone has been measured at 303 ± 2 K. The CCl3 radicals were generated by the pulsed laser photolysis of carbon tetrachloride at 193 nm. The time profile of CCl3 concentration was monitored with a photoionization mass spectrometer. Addition of the O3–O2 mixture to this system caused a decay of the CCl3 concentration because of the reactions of CCl3 + O3 products (5) and CCl3 + O2 products (4). The decay of signals from the CCl3 radical was measured in the presence and absence of ozone. In the absence of ozone, the O3–O2 mixture was passed through a heated quartz tube to convert the ozone to molecular oxygen. Since the rate coefficient for the reaction of CCl3 + O2 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 cm3 molecule−1 s−1 and was also found to be independent of the total pressure (253–880 Pa of N2). This result shows that the reaction of CCl3 with O3 cannot compete with its reaction with O2 in the ozone layer. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 310–316, 2003