影像科学与光化学 ›› 1992, Vol. 10 ›› Issue (2): 144-150.DOI: 10.7517/j.issn.1674-0475.1992.02.144

• 研究论文 • 上一篇    下一篇

以共价键相连的卟啉-酞菁化合物分子内能量传递及光诱导电子转移

周庆复, 田宏健, 沈淑引, 许慧君   

  1. 中国科学院感光化学研究所, 北京 100010
  • 收稿日期:1990-10-31 修回日期:1991-04-16 出版日期:1992-05-20 发布日期:1992-05-20
  • 通讯作者: 周庆复
  • 基金资助:
    国家自然科学基金;中国科学院长春物理研究所激发态物理开放研究室

INTRAMOLECULAR ENERGY TRANSFER AND PHOTOINDUCED ELECTRON TRANSFER IN A COVALENTLY LINKED PORPHYRIN-PHTHALOCYANINE

ZHOU QING-FU, TIAN HONG-JIAN, SHEN SHU-YIN, XU HUI-JUN, CHEN DE-WEN   

  1. Institute of Photographic Chemistry, Beijing 100101, P.R. China
  • Received:1990-10-31 Revised:1991-04-16 Online:1992-05-20 Published:1992-05-20

摘要: 合成了叶啉与酞菁以共价键连接起来的双发色团分子。测定了它们的吸收光谱,荧光光谱,荧光寿命等。计算了分子内能量传递过程的效率(φEnT)及速率常数(κEnT)。结果表明:在稀溶液中,卟啉与酞菁等克分子混合时,观察不到分子间能量传递过程现象的发生;而双发色团分子的分子内能量传递过程则明显发生了,其效率(φEnT=13~70%)与速率常数(κEnT=1.2×107~2.0×108s-1)取决于分子的结构类型。电子转移与能量传递过程与介质性质有关。在极性溶剂中有利于电子转移过程的进行,而不利于能量传递过程;在非极性溶剂中,则有利于能量传递过程的进行,而不利于电子转移。 选择性激发酞菁发色团,观测到了只有电子转移发生的过程,其电子转移效率达到38%。

关键词: 卟啉, 酞菁, 共价键相连卟啉-酞菁, 分子内能量传递, 分子内电子转移

Abstract: A covalently linked porphyrin-phthalocyanine heterodimer was synthesied, the absorption spectra, fluorescence spectra, fluorescence lifetime and redox potantials were determined. There is a considerable overlap between the fluorescence spectrum of porphyrin and the ground state absorption spectrum of phthalocyanine, indicating that energy transfer should be extremly efficient. The efficiency and rate constant of intramolecular energy transfer (lEnT) from porphyrin moiety to phthalocyaneine in each model was measured in polar and non-polar solvent. Neither fluorescence quenching by dipole-dipole interaction, nor quenching by collision occurs in dilute mixture of monomers (1/1 mixture of TTP & PC). In contrast, selective excitation at 420nm of the heterodimer, a decrease of the porphyrin fluorescence, concomitant with a slight increase of phthalocyanine fluorescence occurs, indicating IEnT reaction takes place. The efficiency and rate constant of IEnT depends on heterodimer.Selective excitation of the phthalocyanine chromophore in heterodimer, intramolecular electron transfer (IET) takes place only. The efficiency of IET is rather high (38%). IEnT and IET process takes place in competition with different solvent. IEnT process is a very efficient in non-polar solvent, but IET process is a very efficient in polar solvent.

Key words: porphyrin, phthalocyanine, porphyrin-phthalocyanine heterodimer, intramolecular energy transfer, intramolecular electron transfer