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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (1): 47-53. 上一篇    下一篇

研究论文

HCF(X~1A’)+SO2反应的动力学研究

杨学良，徐刚，陈旸，陈从香*   

  1. (中国科学院选键化学开放实验室 中国科学技术大学化学物理系 合肥 230026)
  • 投稿日期:2005-03-03 修回日期:2005-09-27 发布日期:2006-01-14
  • 通讯作者: 陈从香

Kinetic Study on the Reaction of HCF(&Xtilde;1A’)+SO2

YANG Xue-Liang, XU Gang,CHEN Yang, CHEN Cong-Xiang*   

  1. (Open Laboratory of Bond-selective Chemistry, Chinese Academy of Sciences, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026)
  • Received:2005-03-03 Revised:2005-09-27 Published:2006-01-14
  • Contact: CHEN Cong-Xiang

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用激光光解-激光诱导荧光方法研究了室温下(T＝293 K) HCF(X~1A’)自由基与SO2分子的反应动力学. 实验中HCF(X~1A’)自由基是由213 nm激光光解HCFBr2产生的, 用激光诱导荧光(LIF)检测HCF(X~1A’)自由基的相对浓度随着反应时间的变化, 得到此反应的二级反应速率常数为: k＝(1.81±0.15)×10－12 cm3•molecule－1•s－1, 体系总压为1862 Pa. 高精度理论计算表明, HCF(X~1A’)和SO2分子反应的机理是典型的加成-消除反应. 我们运用RRKM-TST理论计算了此二级反应速率常数的温度效应和压力效应, 计算结果和室温下测定的二级反应速率常数符合得较好.

关键词: HCF(X~1A’)自由基, 激光光解-激光诱导荧光, 反应速率常数, 压力效应, 温度效应

HCF(X~1A’) radicals were produced by laser photolysis of HCFBr2 at 213 nm, and electronically excited from the ground state to X~1A”(030) at 492.70 nm with a dye laser pumped by a Nd∶YAG laser. The reaction rate constant of HCF(X~1A’) with SO2 at room temperature (T＝293 K) was determined to be k＝(1.81±0.15)×10－12 cm3•molecule－1•s－1, when the total pressure was 1862 Pa. Based on the high level ab initio calculations, the mechanism of this reaction was proved to be a typical addition-elimination reaction. The temperature and pressure dependences of the total reaction rate constant were calculated by applying RRKM-TST model. The calculations could provide a well consistent description for our experimental work.

Key words: HCF(X~1A’) radical, laser photolysis/laser induced fluorescence, reaction rate constant, pressure dependence, temperature dependence