【作者】 张娜；

【导师】 吴振奕；

【作者基本信息】 厦门大学 ， 无机化学， 2009， 硕士

【摘要】 近年来,分子内电荷转移化合物的合成及性能研究引起了人们极大的兴趣,这类化合物具有共同的结构特征:即含有电子给体（D）和电子受体（A）。此类化合物具有优良的光电性能转换、非线性光学、离子（蛋白质）识别、光物理、光化学等特性而受到人们极大的关注,已成为科技界研究热点之一。C₆₀具有高度共轭的三维结构、较小的重组能、合适的还原电势等特点,使其成为良好的电子受体（A）。卟啉是一类共轭大环富电子化合物,是理想的电子给予体（D）,而且具有良好的光、热和化学稳定性,在可见光区有很强的电子吸收,在作为半导体、光电功能材料、生物分子材料等方面有着重要的应用。本文合成了一系列共价键连的卟啉-富勒烯化合物,并研究了其光化学性能,希望能为太阳能电池材料的应用研究奠定良好的理论基础。本论文合成了三个系列含有不同推拉电子效应取代基的卟啉-富勒烯化合物。过程如下:首先采用改进的Adler法合成含有三种不同电子效应取代基（-H,-CH₃,-OCH₃）的不对称尾式的羟基卟啉化合物,之后经过酯化反应接枝对羧基苯甲醛得到相应的带醛基卟啉,最后采用1,3-偶极环加成反应,合成了3种具有D-A型电子结构的卟啉—富勒烯配体,并分别与Zn、Cu、Co三种金属离子配位,得到三个系列的Zn、Cu、Co的卟啉—富勒烯配合物,采用质谱（MS）、核磁共振氢谱（¹H NMR）、红外吸收光谱（IR）、紫外-可见吸收光谱（UV-Vis）等多种手段对三个系列12种卟啉富勒烯配合物进行结构分析和表征。通过稳态荧光光谱对含不同电子效应取代基的卟啉（锌卟啉）-富勒烯D-A型化合物的光化学性能进行研究。结果表明:（1）锌卟啉键合富勒烯后,产生了明显的荧光猝灭,表明在光照作用下卟啉—富勒烯化合物发生分子内电荷/能量转移;（2）取代基为-H,-CH₃,-OCH₃的锌卟啉-C₆₀的稳态荧光光谱谱峰波长依次增大并发生红移,这是因为-H,-CH₃,-OCH₃取代基的推电子能力依次增大的缘故。通过循环伏安法研究了卟啉（金属卟啉）-富勒烯化合物的氧化还原性能。结果表明:与富勒烯单体的还原电位相比,卟啉修饰的富勒烯化合物的还原电位均发生明显的负移,这是因为卟啉-富勒烯化合物中电子由卟啉一端向还原中心C₆₀一端的转移,使C₆₀带部分负电荷,得电子能力降低,导致C₆₀更难被还原。结合固体膜紫外可见光谱及循环伏安数据,计算确定各目标产物以及C₆₀、卟啉的能带结构,在此基础上讨论了目标产物中光激发下可能的电子流向,认为卟啉环上电子在光激发后将向C₆₀流动,并形成电荷分离态。这为目标产物作为光电材料的应用奠定了理论基础。更多还原

【Abstract】 In recent years,intramolecular charge transfer compounds attracted great interests of scientists.They share a common structural feature,namely a high degree of delocalization of theπelectronic system connected to the digital electron donor（D） and electron acceptor（A） group.Such molecules are widely used in nonlinear optics, plasma and protein identification,especially in the development and utilization of new energy.Porphyrins are a class of macrocyclic conjugated electron-rich compounds and an ideal electronic donor（D）,moreover,they have a good light,heat and chemical stability,a strong electronic characteristic absorption spectra in the visible region,so the compounds are widely used in the area of semiconductor,photosensitization, optoelectronic functional materials,biological,and so on.Fullerenes,in particular, have been found to make ideal acceptors in model photosynthetic system,due to their unique three-dimensional structure,the remarkable small reorganization energy, photophysical,electrochemical and chemical properties.In recent years,we have made good use of porphyrin complexes and their unique electronic structure and electro-optical performance to design and synthesis the optoelectronic functional materials and devices.It has become a very active research field.So the D-A compounds with its superior performance are widely used in mimicking energy conversion,photophysical,electrochemical and so on.In this paper,we synthesized three series of porphyrin-fullerene compounds. Porphyrin and porphyrin-fullerene ligands with diverse electronic effects substituent groups were synthesized by 1,3-dipolar cycloadditon reaction.Reaction of ligands with M（Ac）₂·nH₂O（M=Zn,Cu,Co） in methanol and chloroform,generating metalloporphyrin-fullerenes.All new compounds were characterized respectively by IR、MS、¹H NMR and UV-Vis.The photochemical properties of porphyrin-fullerene and zincporphyrin-fullerene complexes were measured by steady-state fluorescence spectra.The results showed that:（1） strong quenching in porphyrin-fullerenes was observed obviously in dichloromethane solution.（2） Red shifts in the fluorescence spectra was controlled by different electronic effects substituent groups（i.e.-H,-CH₃,-OCH₃）.The oxidation and reduction properties of the target products were studied by cyclic voltammetry.The results showed that the reduction potentials of the compounds have obviously negative shift compared to that of the pure C₆₀.Because the electric charge easily transferred from porphyrin to redox centers C₆₀ of porphyrin-fullerene compounds,suggested C₆₀ more negative and decreased the electron-accepting ability.As a result,C₆₀ was more difficult to reduced.The energy band structure of the target products were determined by UV-Vis specture and cyclic voltammetry.We also discussed the possible flow of electron direction of target products under excitation of light.We ascribe charge-separate state to the electron of porphyrin ring flow to C₆₀ under photoexitation.This afford potential applications of photoelectric materials of target products to theoretical foundation.更多还原