Molecular Design And Application Of Organic Red Materials

With the continuous development of science and technology,organic photoelectric functional materials have gradually entered human life,like screen display,laser irradiation,and fluorescence imaging are becoming more and more popular.With the increasing demand for these materials in daily life,it's become increasingly important to design and synthesis of more efficient and cheap luminescent materials.Among them,organic red luminescent materials are widely used because of their low fluorescence background interference,strong penetration ability and low excitation energy.However,the band gap of the red light material is narrower than that of the blue and green luminescent,and the exciton is extremely prone to non-radiative transitions that lead to fluorescence quenching,which makes the preparation more difficult.Therefore,the new organic red luminescent material system is expanded to design,and more functions organic red luminescent materials have become the research hotspot of many scholars.In this subject,two types of anthraquinone and porphyrin red organic emitter materials are selected for detailed spectroscopy research and preliminary application exploration in terms of red organic emitter materials OLED and biomedical imaging applications.First of all,five anthraquinone compounds with aggregation-induced emission(AIE)were designed and synthesized of DATPE,TATPE,NTATPE,DA3 CZ and DA9 CZ.The structure was characterized by nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time of flight mass spectrometry.The thermal stability test shows that they have well thermal stability.Through electrochemical tests,HOMO,LUMO and Eg of five compounds are obtained.Through the solvation effect test,it's shown that all five molecules are standard CT state,and the excited state is more sensitive to the polarity of the solvent.The preliminary application of OLED shows that TATPE has excellent external quantum efficiency,its EQE is 10.53%,and its CIE color coordinate is(0.56,0.44).At the same time,choosing the phenyl group at position 3 to be connected to anthraquinone can make the spectrum red-shift and realize the transition from orange-red light color to red light color.In order to obtain better photosensitizers materials for photodynamic therapy,porphyrin compounds of TBPP,TBPP-Zn,TBPP-Ni with strong singlet oxygen generating capacity are designed and synthesized.At the same time,in order to make the light color more red,the introduction of thiophene groups to synthesize TSPP,TSPP-Zn and TSPP-Ni.The structure was characterized by nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time of flight mass spectrometry.The electrochemical tests showed that the introduction of metal Zn significantly changed the electron cloud of TBPP-Zn and TSPPZn,both of which had shallower HOMO and deeper LUMO.The test of the luminescence performance in the aggregation state shows that when the metal Zn is introduced,not only increases the fluorescence intensity at 650 nm,but also changes the molecular conformation,showing weak AIE characteristics.The solvation performance test shows that the porphyrin is particularly large conjugated structure is not affected by the polarity of the solvent,and the introduction of the thiophene group has successfully obtained molecules that emit more red light.The cell imaging experiments show that fluorescence imaging is successfully observed when staining cells at a low concentration of 1 ?mol/L.Through the molecular design of these six compounds,it was proved that the introduction of Zn distorted the molecular conformation and improved the ability to produce singlet oxygen.The non-toxicity of TBPP-Zn made the next functional design more meaningful.