Synthesis And Study Of AIE Compounds With Phenylethene Structure

Recently,organic light-emitting diodes(OLED)have got rapid development.Organic luminescent materials play a vital role in promoting the performance of OLED.Luminescent materials with aggregation-induced emission(AIE)effect are weakly emissive or non-luminescent in dilute solution but will emit efficiently in aggregate state.Because of the efficient luminescent property in solid state,AIE-active materials have been considered as an effective way to obtain high efficiency electroluminescent(EL)materials.For the sake of exploring new EL materials with charge-transport properties and AIE effect,in this thesis,we synthesized and characterized six new arylboron compounds with phenylethene-carbazole skeleton,all these compounds are AIE-active.We fully studied the photophysical properties,thermal properties,electrochemical properties,structure-function relationships of these materials and their applications in OLED devices.The main research contents are as follow:1.Based on related literatures,we obtained useful information about the OLED devices,EL materials,AIE effect and put forward the design philosophy of the whole article.2.The synthesis of the six new materials involves Friedel-Crafts acylation reactions,McMurry coupling reaction,nucleophilic addition reactions,elimination reactions and Suzuki coupling reactions.These arylboron compounds with phenylethene-carbazole skeleton were fully characterized through NMR,MS and elemental analysis.3.The photophysical properties,thermal properties and electrochemical properties of these compounds were investigated.The results showed that these compounds possess good thermal stability,electrochemical stability,excellent luminescence property and remarkable AIE characteristic.Crystal structure analyses were carried out to reveal the AIE mechanism of thse compounds.Based on the results of crystal analyses,we think that the twisted molecular conformations and hydrogen bonding interactions between molecules promote the AIE characteristic of these compounds.According to the results of photophysical properties and theoretical calculations,we think that the differences in conjugation degrees and link modes affect the intramolecular electron effects,thus photophysical and electroluminescence properties of the compounds are also affected.4.Six non-doped OLED devices were fabricated with these materials as light-emitting layer,the performance of these devices was studied.The six devices showed green,blue and yellow light emission,respectively.All these devices showed low turn-on voltage,high brightness and high current efficiency.These AIE compouds are potential good electroluminescent materials.Our research provides new ideas and methods for the further study of the aggregation-induced luminescent materials and OLEDs.