Synthesis And Properties Of Perylene Diimide Derivatives

Perylene diimide（PDI）derivatives are a class of polycyclic aromatic hydrocarbon derivatives with strongπ-πconjugation.These materials have excellent thermal stability and optoelectronic properties and are widely used in field effect transistors,fluorescence sensing and imaging.The introduction of substituents in the bay position or imide can improve the solubility of PDI molecules,and at the same time cause changes in the structure of the aggregated state of PDI derivatives,which in turn gives them new luminescence properties and ion detection performance,and is of great scientific significance and application value.In this dissertation,a series of new PDI derivatives,BPOSS-PDI-Chol,OPOSS-PDI-Chol and Chol-PDI-Chol,were synthesized mainly from1,6,7,12-tetrachloro-3,4,9,10-perylenetetracarboxylic dianhydride,modified by introducing cholesterol（Chol）substituent and caged sesquioxane（POSS）in the imide position.Thermogravimetric experiments showed that all three samples have good thermal stability,and the results of differential scanning calorimetry and X-ray diffraction experiments indicated that Chol-PDI-Chol and BPOSS-PDI-Chol have highly ordered crystal structures.The photophysical properties of the three samples were investigated by UV-Vis absorption spectroscopy,fluorescence emission spectroscopy and circular dichroism spectroscopy,and the results showed that the introduction of modified groups with large steric hindrance,BPOSS and OPOSS,can effectively hinder the intermolecular stacking of PDI and thus improve its fluorescence intensity in the aggregated state.The results of circular dichroism spectroscopy indicated that Chol-PDI-Chol has circular dichroism absorbing properties under specific solvent conditions.In addition,perylene diimide（PDI-TES）derivatives containing siloxane substituents were synthesized by a simple one-step reaction,and the aggregated state structure,self-assembly behavior and fluoride ion detection performance of PDI-TES were investigated by X-ray diffraction,UV-Vis absorption spectroscopy and fluorescence emission spectroscopy.The experimental results showed that based on the silica-oxygen bond-breaking mechanism,PDI-TES can quantitatively detect fluoride ions with high selectivity and sensitivity,and the detection limit is 1.58×10^-6M.It has potential applications in fields such as fluorescence sensing.