Preparation And Properties Of Perylene Diimide Derivatives Containing Siloxane Groups

Perylene diimide(PDI)derivatives are a kind of polycyclic aromatic hydrocarbons with strong?-?conjugation,good molecular coplanarity,high photo,thermal and chemical stability and high fluorescence quantum yield.Thus they are a kind of photoelectric materials with excellent performance and widely used in fluorescent probes,organic light-emitting diodes and solar cells and so on.In this dissertation,we used 3,4,9,10-perylenetetracarboxylic dianhydride as the starting material to prepare three PDI derivatives with different siloxane groups through condensation reaction.Then through multiple synthesis reactions and hydrosilylation,we successfully fabricated another siloxane molecule with longer alkyl chains and siloxane substituents.The chemical structures and thermal stability of these synthetic compounds were characterized by~1H NMR and TGA respectively.Basedontheseresults,weusedfluorescencespectroscopy,DSC,one-dimensional X-ray diffraction and two-dimensional X-ray diffraction to study the self-assembly behavior,aggregation structure and photoelectric properties of these prepared compounds.From the experiments,we knew that the sample with longer siloxane chains first develops into a columnar liquid crystal structure at room temperature and then a highly ordered crystal structure after cold crystallization with temperature increasing.Based on this,we further tested the carrier transport performance of this sample.The results showed that when the sample is in the liquid crystal structure,no obvious signal is found.But after cold crystallization treatment,the carrier transport performance is significantly improved and the carrier mobility value is 1.41x10~-33 m~2/Vs measured by time of flight experiment.In addition,we introduced sulfur atoms at the bay positions of perylene diimide molecules and prepared two different derivatives.On the dual role reactions of fluoride-triggered Si-O bond cleavage and electron transfer,fluorescence intensity of S-heterocyclic annulated perylene diimide(SPDI)in tetrahydrofuran solution was significantly decreased,even quenched after adding fluoride ions observed through fluorescence spectroscopy.However the addition of other ions did not cause significant changes in fluorescence intensity.Therefore,SPDI has the advantages of high sensitivity and selectivity,and quick response in the detection process of fluoride ions,and is expected to be made into fluorescent probes for rapid detection of fluoride ions.