Design, Synthesis And Properties Of Diketopyrrolopyrrole-Polvcatenar Molecule And Pyridine-Containing α-Cvanostvrene Molecule

The liquid crystal unites the order of the crystal and the fluidity of the liquid at the molecular level,so that the system can adopt the lowest energy configuration to respond to external stimulation（magnetic field,electric field,chemical and mechanical force）,so the liquid crystal is in many aspects both that it has important applications.We introduce fluorescent groups into the liquid crystal cell,and combine the photophysical properties and order of the liquid crystal,and hope to obtain a multifunctional liquid crystal with excellent properties.Diketopyrrolopyrrole（DPP）,α-cyanostyrene,etc.are all fluorescent groups with excellent photophysical properties,while DPP andα-cyanostyrene derivatives are easy to modify and have high fluorescence quantum yields.And other excellent characteristics.Therefore,the introduction of these conjugated units into liquid crystal molecules is expected to obtain functional liquid crystal compounds with complex self-assembled structures.The first chapter is the design and synthesis of diketopyrrolopyrrole series（D-R）fluorescent probes.The D-R probe system is developed based on the interaction between solvent analytes,DPP fluorescent derivatives and silica matrix.According to the different polarity of the probe,the fluorescence intensity is different in various solvent analytes,so as to achieve the identification of methanol,ethanol,ethylene glycol and water;the cycle quantum yield test with water as the solvent analyte It shows that the fluorescence quantum yield of D-P and D-C can be restored,while the quantum yield of D-B will gradually decrease,and the fluorescence quenching is irreversible.Based on the above research,it is shown that the probe D-R can clearly distinguish ethanol,water and methanol which is harmful to human body and can be recycled.This chapter provides a new way for the research of convenient and affordable probes.The second chapter is based on the synthesis and performance of D-A-D Polycatenar-diketopyrrolopyrrole（DPP）molecule.In this chapter,D-A-D-type Polycatenar-diketopyrrolopyrrole（DPP）molecular series compounds（DPPR）were prepared by Sonogashira-Hagihara coupling reaction,respectively DPPB/14,DPPH/14,DPPO/14,DPPP/10,DPPP/14 and DPPP/16.This chapter studies the liquid crystal properties,photoelectric properties and gel assembly properties of the series of compounds.Studies have found that with the changes of the polar functional groups and alkyl chains of the compounds,the compounds DPPP/14 and DPPP/16can be assembled into columnar liquid crystals(Col_hex/P6mm)at high temperatures and at low temperatures（Cub _V/Ia3d）,DPPP/10 can only formed（Cub _V/Ia3d）,while the compounds DPPB,DPPH,and DPPO do not have liquid crystal properties.In addition,the compound DPPR can form a multi-stimulus-responsive organogel with a spiral morphology,and as the polarity of the solvent increases,the gel formation becomes more orderly.Photophysical studies have shown that these compounds can exhibit a broad and strong absorption band in the range of 275-650 nm,and can emit strong fluorescence in the NIR region（650-850 nm）,and have a low energy gap（1.94e V）.In addition,the test of ion conductivity(the conductivity is 3.9×10^-7 S m^-1)shows that the compound has a certain the resistance.Based on the above research,the compound DPPP/n has excellent liquid crystal assembly properties,optoelectronic properties and gel assembly properties,indicating that this type of multifunctional material has broad application prospects in liquid crystal displays,gel materials,organic optoelectronic materials,and resistive materials.The third chapter is based on the design,synthesis and properties of pyridine andα-cyanostyrene molecules.In this chapter,Knoevenagel condensation and Suzuki coupling reactions are used as key steps to design and synthesizeα-cyanostyrene compounds BD/n,and study the thermal assembly properties,AIE properties and ion recognition properties of the compounds.Studies have found that the compound does not have liquid crystal properties;after adding different ions,it has been found to have a fluorescence response to CN^-and H⁺,the fluorescence of the solution increased and the color changed,indicating that BD/16 can be used as the fluorescence chemistry of CN^-or H⁺sensor.In addition,through research on the AIE effect of the compound BD/16,it is found that the compound has a good AIE effect and has potential applications in optoelectronic materials.Chapter 4 is the conclusion.Chapter 5 is the experimental part,including detailed synthesis steps and spectral data of the compound.