物理化学学报 >> 2006, Vol. 22 >> Issue (10): 1191-1195.doi: 10.3866/PKU.WHXB20061004

研究论文 上一篇    下一篇

Br2+Cl2=2BrCl反应机理的理论和实验研究

袁丽霞;杨郭英;孙德升;王遵尧;池清清   

  1. 嘉兴学院生物与化学工程学院, 浙江 嘉兴 314001; 南京工业大学化学化工学院, 南京 210009
  • 收稿日期:2006-03-24 修回日期:2006-04-27 发布日期:2006-10-11
  • 通讯作者: 王遵尧 E-mail:wangzun315cn@163.com

Theoretical and Experimental Study on the Reaction Mechanism of Br2+Cl2=2BrCl

YUAN Li-Xia;YANG Guo-Ying;SUN De-Sheng;WANG Zun-Yao;CHI Qing-Qing   

  1. School of Biological and Chemical Engineering, Jiaxing University, Jiaxing 314001, P. R. China; School of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China
  • Received:2006-03-24 Revised:2006-04-27 Published:2006-10-11
  • Contact: WANG Zun-Yao E-mail:wangzun315cn@163.com

摘要: 用(U)MP2方法, 取6-311G*基组, 研究了反应Br2+Cl2=2BrCl的机理, 求得四中心和三中心的过渡态, 通过比较反应通道的活化能的大小, 得到如下结论: 双分子基元反应的最小活化能小于Cl2和Br2的离解能, 在没有光引发的条件下, 标题反应将以分子与分子作用形式完成; 若有光引发, Br2或Cl2先解离成原子, 再经过Br原子与Cl2反应或Cl原子与Br2反应, 能较快完成标题反应. 分别测定了光照和避光两种条件下的反应体系在412 nm处吸光度的变化, 证实了理论研究的结果.

关键词: 溴, 氯, 氯化溴, 过渡态, 反应机理, 分光光度法

Abstract: The gas phase reaction mechanism of Br2+Cl2=2BrCl had been investigated by (U)MP2 at 6-311G* level, and a series of four-centered and three-centered transition states were obtained. Comparing the activation energies of three reaction paths, the result was achieved as follows: the minimum activation energy of the bimolecular elementary reaction Br2+Cl2=2BrCl was less than the dissociation energies of Br2 and Cl2. It was thus theoretically proved that the titled reaction occurred more easily in the bimolecular form without light initiation. However, if the reaction system was initiated by light, the titled reaction was completed quickly through the reaction path of Br atom reacting with Cl2 or Cl atom reacting with Br2. The theoretical result was further verified by determination of the absorbency (with or without light initiation) at 412 nm.

Key words: Bromine, Chlorine, Bromine chloride, Transition state, Reaction mechanism, Spectrophotometry