Synthesis And Properties Of High Flourescent ?-cyanostilbenzene Ligands And Organic Boron Compounds Liquid Crystal

Fluorescent liquid crystal materials means that the liquid crystal material with excellent luminescent property in the liquid crystal phase of the compound,and its remarkable characteristics is high fluorescence and high quantum yield.This property requires that the material itself must overcome the aggregation induced quenching(ACQ)effect,means high fluorescence retained in aggregation state.The purpose is to realize the high efficiency and energy conservation of the liquid crystal display device by the luminescence property.In these liquid crystal materials,cyanostilbene derivative attracts wide attention with the typical aggregation induced emission property and strong fluorescence in high concentration state.According to the international research progress on the luminescent liquid crystal materials,Schiff base unit with excellent liquid crystalline property,introduced into ?-cyanostilbene structure.A series of liquid crystal ?-cyanostilbene derivatives were designed and synthesized with the molecular ratio of length to diameter is adjusted by changing the length of the flexible chain in the end.And by introducing the electron deficient boron atoms,modifying the structure of Schiff base,a series of high fluorescent organic boron ?-cyanostilbene derivatives were designed and synthesized.Their photophysics properties were investigated by absorption spectra and fluorescence spectra,their liquid crystal properties and luminescence anisotropy were investigated by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC)and polarized light microscopy(POM).The main research contents are as follow:1.A series of Schiff base cyanostilbene derivatives were designed and synthesized and a series of organic boron compounds were preparation in this paper.The target compounds were characterized by FT-IR,1H-NMR and 13C-NMR.2.The photophysics properties of Schiff base a-cyanostilbene derivatives were investigated with absorption spectra and fluorescence spectra.The liquid crystal properties and luminescence anisotropy of Schiff base a-cyanostilbene derivatives were investigated with thermogravimetric analysis,differential scanning calorimetry and polarized light microscopy.The results show that Schiff base a-cyanostilbene derivatives include the characteristics of high thermal stability,wide liquid crystal phase and more liquid crystal phase.The rule of liquid crystal phase width with the change of the length of flexible chain:increased and then decreased,and the phase transition points were gradually reduced to near room temperature.Some Schiff base compounds retained the characteristics of high solid fluorescence and polarized luminescence.3.The photophysics properties of organic boron compounds a-cyanostilbene derivatives showed that the compounds with the characteristics of high molar absorption coefficient,strong solution and solid-state luminescence and high quantum yield.thermogravimetric analysis(TGA),differential scanning calorimetry(DSC)and polarized light microscopy(POM)show that organic boron compounds have excellent thermal stability,stable liquid crystalline phase and strong fluorescence.And most of them possess obvious self assembly process and the good response to electric field.