物理化学学报 >> 1996, Vol. 12 >> Issue (01): 12 -17 .doi: 10.3866/PKU.WHXB19960104

研究论文 上一篇    下一篇

卟啉酞菁模型化合物光致电子转移研究

陈建新, 田宏健, 张红灏, 周庆复, 许慧君, 徐广智   

  1. 北京分子动态及稳态结构国家重点实验室|中国科学院化学研究所|北京 100080;中国科学院感光化学研究所|北京 100101
  • 收稿日期:1994-11-05 修回日期:1995-05-09 发布日期:1996-01-15
  • 通讯作者: 陈建新

Study on the Intramolecular Electron Transfer of TTP-(CH2)n-Pc

CHEN Jian-Xin, TIAN Hong-Jian, ZHANG Hong-Hao, ZHOU Qiang-Fu, HU Hui-Jun, XU Guang-Zhi   

  1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080;Institute of Photographic Chemistry,Chinese Academy of Sciences,Beijing 100101
  • Received:1994-11-05 Revised:1995-05-09 Published:1996-01-15
  • Contact: Chen Jian-Xin

摘要:

本文采用时间相关单光子计数对卟啉酞菁TTP-(CH2)n-PC模型化合物的光致电子转移进行了研究.发现激发Pc时,呈现单指数衰减,n=4时电子转移速率最快,激发TTP时呈现双指数衰减,表明除能量转移外,同时存在电子转移,随n的增大电子转移速率减小,活化能、重排能增加, 电子转移效率下降,电子转移反应△GCS与电荷分离活化络合物衰变速率kCT,按以下规律:
△G CS (5) >△G CS (3) >△G CS (4) >△G CS (2)
kCS (2) >kCS (3) >kCS (4) >kCS (5)
其△G CS (4) 与△G CS (3)倒置可按Marcus理论中重排能啬使活化能增加得以解释。

关键词: 卟啉酞菁, 电子转移, 事件相关单光子计数, 荧光

Abstract:

The intramolecular electron transfer of TTP-(CH2)n-Pc was studied by means of time correlated single-photon counting method. When the Pc subunit of the compound is excited, the fluorescence of the compound is quenched by intramolecular electron transfer and the electron transfer is most favorable in the compound with n=4. When the TTP subunit of the compound is excited, the fluorescence decay of the compound will be biexponential, which shows the existence of an electron transfer process. Some kinetic parameters were derived from the experimental data. With n increasing, the activation energy and the reorganization energy increases whereas the electron transfer rate decreases. Moreover, the free enthalpy change of electron transfer reaction △G CS and the charge-separated rate kCS are in the order of:
△G CS (5) >△G CS (3) >△G CS (4) >△G CS (2)
kCS (2) >kCS (3) >kCS (4) >kCS (5)
The difference between the order of △G CS and of electron transfer rate can be interpreted according to Marcus theory.

Key words: Porphyrin-phthalocyanine, Electron transfer, Time correlated single photon couting, Fluorescence