卟啉酞菁模型化合物光致电子转移研究

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＾（５）ＣＳ〉△＾（３）ＣＳ〉△＾（４）ＣＳ〉△＾（２）ＣＳ，ｋ＾（２）ＣＳ〉ｋ＾（３）ＣＳ〉ｋ＾（４）ＣＳ〉ｋ＾（５）ｃｓ。其△Ｇ＾

Study on the Intramolecular Electron Transfer of TTP-(CH_2)n-Pc

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.