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化学学报
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化学学报 ›› 2002, Vol. 60 ›› Issue (2): 256-260. 上一篇    下一篇

研究论文

CCl2(A^1B1)自由基不同振动态的猝灭动力学

高义德;冉琴;陈yang;陈从香   

  1. 中国科学院选键化学开放实验室.南京(210008);中国科学技术大学化学物理系. 安徽(230026)
  • 发布日期:2002-02-15

The collisional quenching of CCl2(A^1B1) in different vibrational states by quenchers

Gao Yide;Ran Qin;CHEN ya;Chen Congxiang   

  1. Nanjing Inst Geol & Palaeontol, Acad Sinica, Selective Oxidat.Nanjing (210008);Univ Sci & Technol China, Dept Chem Phys.Anhui(230026)
  • Published:2002-02-15

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1

对CCl4/Ar混合气体直流脉冲放电产生CCl2自由基，再分别用波长为550.56nm,541.52nm,532.25nm,524.31nm,523.82nm和523.27nm的激光将电子基态CCl2激励到激发态A^1B1的(0,3,0),(0,4,0),(1,3,0),(0,6,0),(1,4,0),(2,2,0)振动态，激发态CCl2(A^1B1)的不同振动态的时间分辨荧光信号显示该信号呈双指数衰减，测得室温下CCl2(A^1B1)不同振动态被NH3,H2O,CH2Br2,NH(CH3)2,NH(C2H5)2,N(C2H5)3,n-C6H14等分子猝灭的实验结果，用三能级模型分析处理实验数据，获得态分辨速率常数kA和ka值，并对实验结果进行了讨论。

关键词: 自由基反应, 三能级模型, 放电, 二氯卡宾, 振动态, 猝灭, 动力学

CCl2 free radicals were produced by D. C. discharge of CCl4(in Ar). Ground electronic state CCl2 radical was electronically excited to A^1B1 (0, 3, 0), (0, 4, 0), (1, 3, 0), (0, 6, 0), (1, 4, 0) and (2, 2, 0) vibronic states by Nd:YAG laser pumped dye laser at the wavelength of 550.56, 541.52, 532.25, 524.31, 523.82 and 523.37 nm, respectively. Experimental quenching rate data of CCl2(A^1B1 and a^3B1) by NH3, H2O, CH2Br2, NH(CH3)2, NH(C2H5)2, N(C2H5)3, and n-C6H14 were obtained by observign the time resolved fluorescence signals from the excited CCl2 radical transitions, which showed a superposition of two exponential decay components. The state-resolved rate constnats kA and ka were acquired by analyzing and dealing with these data by using three-level- model, which was put forward by us.

Key words: FREE RADICAL REACTION, DISCHARGE, DICHLOROCARBENE, VIBRATIONAL STATE, QUENCHING, DYNAMICS

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