化学学报 ›› 2007, Vol. 65 ›› Issue (15): 1415-1419. 上一篇    下一篇

研究论文

介电常数对Stokes频移时间相关性的影响

许婧, 傅克祥, 李象远*   

  1. (四川大学化工学院 成都 610065)
  • 投稿日期:2006-12-05 修回日期:2007-03-08 发布日期:2007-08-14
  • 通讯作者: 李象远

Influence of Dielectric Constant on Time-dependent Stokes Shift

XU Jing; FU Ke-Xiang; LI Xiang-Yuan*   

  1. (College of Chemical Engineering, Sichuan University, Chengdu 610065)
  • Received:2006-12-05 Revised:2007-03-08 Published:2007-08-14
  • Contact: LI Xiang-Yuan

基于连续介质理论,利用溶剂化能计算了香豆素水溶液单球孔穴模型的Stokes频移响应函数. 将水的介电谱实验数据拟合进而得到介电常数理论公式, 并基于此计算了相关函数. 在考虑了延迟时间后, 相关函数的理论计算结果与实验吻合. 考虑到低频响应在溶剂化驰豫中的重要性, 考察了低频极化对响应函数的影响.

关键词: Stokes频移, 介电谱, 溶剂化相关函数

Based on the continuous medium theory, the Stokes shift response function of coumarin in water was investigated using the solvation energy and the spherical cavity approximation. The experimental data of the dielectric spectrum of water has been fitted to a theoretical formula with which the correlation function is calculated. Introducing a retardation time of emission of fluorescence after the vertical excitation of system led to a desirable agreement between the theoretical calculation and the experiment for the correlation function. Considering the importance of the low-frequency response in the solvation relaxation, the influence of the low-frequency polarization on the correlation function has been discussed.

Key words: Stokes shift, dielectric spectrum, solvation correlation function