Design,Synthesis And Spectroscopic Properties Of Piezochromic Materials Based Tetraphenylethene

With the continuous development and progress of society and technology,the use of materials by humans is not satisfied with traditional static materials,so there is an urgent need to develop intelligent materials with dynamic effects to meet new human needs.Piezochromic materials,as a new type of pressure sensitive intelligent materials,can dynamically and reversibly change the fluorescence wavelength under pressure stimulation,and are widely used in pressure sensing,anti-counterfeiting,inkless writing,information storage,and other fields.There have been many reports on molecules with a single piezochromic behavior and AIE properties.However,the design and development of molecules with bidirectional piezochromic behavior as well as molecules with Aggregation Induced Emission(AIE)/Aggregation Caused Quenching(ACQ)effects are still very difficult.In this thesis,using tetrastyrene as a functional precursor,TPE unit modified into the frameworks of imidazole rings,quinoline rings,anthracene nitrogen-containing heterocycles,and phenanthrene nitrogen-containing heterocycles.Through reasonable molecular design,a series of TPE derivatives were prepared,and the luminescence properties of the compounds were controlled by adding π extension systems,changing different substituents,and isomerization,and optical properties of the compounds were studied.The main contents of this paper are as follows:1.Two tetrastyrene-imidazole derivatives were designed and synthesized using 4,5-bis(4-(1,2,2-tristenyl)phenyl)-1H-imidazole as the core unit and pyridine or quinoline as a πextended system,and their optical properties were studied.The experimental results showed that X-1、X-2 had significant AIE properties and opposite pressure induced fluorescence discoloration behavior.After grinding,the solid fluorescence of dye molecule X-1 changed from blue light at 473 nm to green light at 500 nm,with a reversible red shift of 27 nm.However,the solid fluorescence of the dye molecule X-2 changed from 620 nm red light to 546 nm yellow light after grinding,and the reversible blue shift was 74 nm.The mechanism of the opposite piezochromic behavior of X-1 and X-2 was explained through PXRD,SEM,DSC,single crystal analysis,and theoretical calculations.Finally,dye molecules X-1 and X-2 with excellent luminescent properties were used for dyeing B-16 cells,anti-counterfeiting materials,and writable data storage materials,and very good results were obtained.2.Twenty two tetrastyrene-quinoline derivatives were designed and synthesized through the three component cyclization reaction of 4-(1,2,2-triphenylvinyl)benzaldehyde,aniline derivatives,and phenylacetylene derivatives,and their optical properties were studied.Among them,TQ1-12 had a very significant AIE effect,TQ-4 and TQ-11 had TICT effect and solvation effect.After grinding,except for a slight blue shift in the emission wavelength of TQ-9,the maximum emission wavelengths of other TQ1-12 had all undergone a red shift.The molecule TQ13-22 had strong fluorescence emission and solvation effects in solution,and both TQ13-22 had significant ACQ effects.After grinding,the emission wavelengths of most molecules did not significantly shift,and the emission wavelengths of TQ-15,16,20,and 21 shifted blue.The mechanism of different luminescence behaviors of TQ dye molecules was explained by single crystal analysis and PXRD.Finally,they have were applied for the fields of anti-counterfeiting and inkless writing,due to their excellent panchromatic solid-state luminescence performance of 427 nm to 689 nm.3.Six tetra-styrene-anthracene nitrogen-containing heterocyclic derivatives and six tetrastyrene-phenanthrene nitrogen-containing heterocyclic derivatives were designed and synthesized by three-component ring reaction of 4-(1,2,2-triphenylvinyl)benzaldehyde,pphenylenediamine and phenylacetylene derivatives,and their optical properties were studied.Among them,anthracene isomeric molecules had strong fluorescence emission and solvation effect in solution,and they did not emit light in aggregated state,which has traditional ACQ effect.The solid fluorescence of anthracene isomeric molecules is longer,emitting yellow to red fluorescence.After grinding,the fluorescence emission wavelength had blue shift.However,phenanthrene isomeric molecules have almost no fluorescence in solution,but emitting strong fluorescence in aggregated state,which had obvious AIE effect.The solid fluorescence of phenanthrene isomeric molecules is short,emitting blue to green fluorescence.After grinding,the fluorescence emission wavelength had red shift.The mechanism of different luminescence behaviors of anthracene and phenanthrene heterogeneous was explained by single crystal analysis and PXRD.Finally,in view of the excellent luminescent properties of dye molecules,they have were applied to the fields of anti-counterfeiting and inkless writing.