Design,Synthesis And Properties Of Organic Mechanochromic Molecules Based On Conjugated Structure

With the rapid development of modern science and technology,various functional materials have attracted more and more attention.Due to its unique advantages(such as Mechanical force,response,reversibility,etc.),mechanochromic materials have broad application prospects in trademark anti-counterfeiting,information storage,and stress sensing.Such functional fluorescent materials can change the stacking method of molecules and the spatial configuration of molecules when they are subjected to external stimuli(mechanical force,heat,etc.),thereby exhibiting reversible color and fluorescence changes.The purpose of this article is to study the D-?-A organic chromic molecules that can exhibit large fluorescence changes under the stimuli of force,heat,solvent.Chapter 1:The regulation mechanism and types of solid-state fluorescent compounds are reviewed,with emphasis on the types and research status of organic mechanochromic materials.Chapter 2:This chapter designs and synthesizes 4 cyano substituted styrene compounds(P-CNV-PMO,PBu O-CNV-PBu O,PC₁₂O-CNV-PMO,PPh C₂O-CNV-PMO).These compounds have no obvious mechanochromic properties at room temperature,but emit monomeric green fluorescence when heated to a molten state;after being doped with glucose,these compounds can be transformed from excimer to Single state under the action of mechanical force.This research is expected to be able to predict the mechanochromic properties of compounds through theoretical calculations,and be used to guide the design and synthesis of new high-contrast mechanochromic compounds.Chapter 3:In this chapter,three Cy3 compounds were designed and synthesized,named Cy3-d Ph-M,Cy3-d T-M,Cy3-d Ph-d PM,and all three compounds have AIEE properties and good dyschromic properties.In addition,these cyanine dyes can distinguish cancer cells from normal cells and target mitochondria in cancer cells with high selectivity.In vivo animal experiments with mice as a model showed that the cyanine nanoprobe showed the ability to target tumors in mice and has potential application value in tumor monitoring.Chapter 4:In this chapter,3 compounds PM-TP-CN,PMO-TP-CN and Ph₂N-TP-CN have been designed and synthesized,2 of which have good mechanochromic properties,and all 3 compounds have excellent AIE properties,The experimental results are basically consistent with the predicted results,and it is expected that the design principles of high-contrast organic photochromic molecules and AIE can be established through in-depth research.Chapter 5:Thesis summary and outlook.In this thesis,a total of 10 mechanochromic compounds were designed and synthesized,and their properties and mechanisms were studied;and Cy3 mechanochromic cyanine dyes can target mitochondria in cancer cells,and have good application prospects.