化学学报 ›› 2001, Vol. 59 ›› Issue (3): 360-365. 上一篇    下一篇

研究论文

脉冲直流放电-LIF法CCl~2(A'B~1和a^3B~1)自由基被醇类分子 猝灭动力学研究

高义德;陈从香;裴林森;赵欣;陈汤   

  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.安徽(230026)
  • 发布日期:2001-03-15

Kinetic studies on quenching of CCl~2 (A'B~1 and a^3B~1) by alcohols by pulse-DC-discharge method

Gao Yide;Chen Congxiang;Pei Linsen;Zhao Xin;Chen Tang   

  1. Univ Sci & Technol China, Dept Chem Phys.Anhui(230026)
  • Published:2001-03-15

CCl~4/Ar混合气体进行脉冲高压直流放电产生CCl~2自由基,再用YAG泵浦的染料激光输出的541.52nm激光将电子基态CCl~2激励到电子激发态A^1B~1(0,4,0)模的P^R~1能级上,通过检测激发态CCl~2自由基的时间分辨荧光信号,测得了室温下(293K)激发态CCl~2自由基被醇类分子猝灭的动力学结果,根据我们提出的三能级模型来分析处理这些实验数据,首次获得了激发态CCl~2自由基被醇类分子猝灭的态分辨的速率常数k~q~1,k~q~2和k~q~3的值,并对这些数据与猝灭剂的结构关系进行了分析讨论。

关键词: 醇, 猝灭速率常数, 动力学研究, 二氯化碳

CCl~2 free radicals were produced by DC discharge of CCl~4 (in Ar). Ground state CCl~2 radical was electronically excited to P^R~1 level of A^1B~1(0, 4, 0) state with Nd:YAG laser pumped dye laser at 541.52 nm. Experimental quenching data of CCl~2 (A 1^B~1 and a 3^B~1) by alcohols were obtained by observing time-resolved fluorescence signals from the excited CCl~2 radicals transition, which showed a superposition of two exponential decay components. The state-resolved rate constants k~q~1, k~q~2 and k~q~3 were acquired for the first time by analyzing the data using three-level-model developed by us. The k~q~1, k~q~2 and k~q~3 increase on the whole with increasing the number of C-H bonds in alcohols. A discussion on the effect of OH group and molecular structure in alcohol on the effect of OH group and molecular structure in alcohol on the quenching of excited CCl~2 radical is presented.

Key words: ALCOHOL, KINETIC STUDY

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