物理化学学报 >> 1997, Vol. 13 >> Issue (08): 680-684.doi: 10.3866/PKU.WHXB19970802

研究论文 上一篇    下一篇

给体-受体体系分子内光致电子转移反应研究

李顺来,董晓阳,许慧君   

  1. 中国科学院感光化学研究所,北京 100101
  • 收稿日期:1996-12-02 修回日期:1997-04-08 发布日期:1997-08-15
  • 通讯作者: 许慧君

Intramolecular Photoinduced Electron Transfer in Donor-BA-Acceptor Systems

Li Shun-Lai,Dong Xiao-Yang,Xu Hui-Jun   

  1. Institute of Photographic Chemistry,The Chinese Academy of Sciences,Beijing 100101
  • Received:1996-12-02 Revised:1997-04-08 Published:1997-08-15
  • Contact: Xu Hui-Jun

摘要:

对一类以9,10-二甲氧基蒽为给体,双酚A为连接链连接不同受体的电子给体-受体体系,通过单光子计数法测定荧光寿命,计算了各体系内的光致电子转移反应速率常数,通过测定氧化还原电位,计算出各电子给体-受体体系电子转移反应的自由能变化.并根据电子转移反应理论对光致电子转移速率常数与自由能变化关系进行了理论计算分析,发现本文各体系的光致电子转移速率常数的实验值与电子转移反应理论曲线吻合得比较好,同时也揭示在该类给体-受体体系中未出现电子转移反转区的原因在于电子转移过程自由能变化(-ΔG)没有足够大.

关键词: 光致电子转移, 9, 10-二甲氧基蒽, 双酚A

Abstract:

Intramolecular photoinduced electron transfer in a series of donor-acceptor systems consisting of 9,10-dimethoxyanthracene and differently substituted benzoic esters have been investigated. From fluorescence life-time measurements using single-photon counting technique, the rate constants of electron transfer ket were obtained. The free energy changes ΔG of electron transfer from the first excited state of 9,10-dimethoxyanthracene were obtained by determining the redox potentials of the donor and the acceptors and the first excitation energy. The dependence of photoinduced electron transfer rates on the exothermicity of the reaction has been studied by the theoretical analysis based on quantum mechanical treatments of electron transfer. The results show that the experimental values coincide well with that obtained by theoretical calculations. Although the inverted region is not seen in our results, the present treatment predicts that the inverted region would be observed at still lower values of ΔG than so far examined.

Key words: Photoinduced electron transfer, 9,10-dimethoxyanthracence, Bisphenol A