Design, Synthesis And Aggregation Properties Of Perylene Tetracarboxylic Diimide Derivatives With Different Sides Alk Chains

Self-assembled π-conjugated systems have attracted tremendous attention in the past years owing to their potential application in organic electronics. Numerous functional π systems molecules, for example, perylenetetracarboxylic diimide (PDI), porphyrins, phthalocyanines and so on have been intensively investigated aiming to their application as organic semiconductors, solar energy conversion, liquid crystal materials, biological fluorescent probes and solar cells and so on.In recent years, emphasis has been given on the organization of tailored functional π systems by self-assembly leading to one-dimensional stacks of π-π aggregates in solution, in organogels, and in columnar liquid crystalline (LC) phases. Driven by the demands of diverse applications, the modification on molecular structure of PDI aimed at changing the photophysical properties is one of the most active fields of PDI studies. How to find a structure with novel properties has always been a problem in this area. In this paper, in order to find the relationship between structure and properties of PDIs, we introduced some functional groups to the PDI compounds, endowed these molecules with some special functions and studied their influence on the properties. The content of this thesis includesChapter1, the synthesis, properties and applications of perylenetetracarboxylic diimide derivatives have been reviewed. The research progress of supramolecular aggregates based on Perylenetetracarboxylic Diimides is selected as the focus of this research.Chapter2, Two new perylenetetracarboxylic diimide (PDI) erivatives, namely, trimer1and trimer2, composed of three PDI units with different tail groups, are prepared. Solubility of these two trimers is significantly different due to the different tail groups. The aggregation behavior of these two compounds in solution was investigated using absorption and fluorescence spectra. The results indicate that both trimers1and2can form large molecular aggregates via an intermolecular process in either good solvent or poor solvent. Trimer1can form gel in a mixed solvent of methanol and tetrahydrofuran (THF), while trimer2can only form gel in non-polar solvents, such as hexane and toluene. This can be ascribed to the multiple long alkyl chains in trimer2, which have introduced extra hydrophobic interactions besides the π-π interactions between the molecules of trimer2. The morphology examination of the dried gel of trimer1by atomic force microscopy (AFM) reveals simply long fibers. But, the dried gel of timer2shows network-like morphology, which can be ascribed to the hydrophobic interactions between the multiple alkyl chains.Chapter3, Four monomers of perylenetetracarboxylic diimide (PDI) erivatives was prepeared. The aggregation behavior of these compounds in solution was investigated using absorption and fluorescence spectra. The results indicate that four monomers form "H" aggregates in poor solvents. The aggregates prepeared by phase transfer ware examined by SEM, the results indicate that compound1-3form long nonoribbons.while, compound4forms heliciform long nonoribbons, which can be assignable to interdigitation of long branch. The electrical conductivity of them was investigated by conductivity meter, the electrical conductivity suggested that four monomers may be good semiconductor materials.