Synthesis And Properties Of Force And Photoresponsive Fluorescent Derivatives Based On Carbazole,Fluorene Or Diallylene Groups

Up to now,organic luminescent materials have attracted much attention in the fields of sensors,memory,safe ink biology and medical applications due to their high-efficiency luminescent properties.Among them,mechanical force-induced materials,as a kind of intelligent materials,have attracted more and more attention of researchers because of their stimulating response to external mechanical forces.However,traditional fluorescent materials will cause aggregation fluorescence quenching?ACQ?in the aggregation state.Fortunately,Academician Tang Benzhong and others discovered an interesting aggregation induced luminescence?AIE?phenomenon in 2001.Contrary to the phenomenon of aggregation fluorescence quenching,fluorescent materials with AIE effect hardly emit light in dilute solution,but their fluorescence intensity is greatly enhanced in the aggregation state.More interestingly,most compounds with AIE effect usually also have mechanical color-changing properties,which is of great significance to the development of mechanical color-changing materials with obvious solid-state luminescence and color contrast.In addition,photochromic materials,as stimulus response materials,have extremely high application prospects in optical information storage.Among many photochromic materials,diarylethene derivatives have attracted much attention of scientists in colorimetric detection and fluorescence detection due to their excellent color-changing performance and fatigue resistance.To sum up,the main body of this paper.The first chapter introduces the research background of AIE phenomenon and its mechanism and classification.In addition,the contents of mechanical photochromic materials and photochromic materials are also reviewed.Through a brief summary of two kinds of intelligent materials with stimulus response,the research content of this paper is put forward.In the second chapter,four new fluorescent compounds containing carbazole and fluorene units are designed and prepared.Experimental studies show that,compounds M-1,M-2,M-3 and M-4 have obvious solid-state fluorescence characteristics and reversible mechanical discoloration properties.Among them,illuminants M-1 and M-2 show reversible mechanical fluorescence conversion between blue-green and yellow-brown emission colors,and illuminants M-3 and M-4 show color changes from green or yellow to yellow-brown.In addition,the repeatability of the mechanical discoloration phenomenon of the four compounds is very good.This work provides valuable reference for the development of high contrast mechanical color-changing materials.In the third chapter,,two novel diarylethene chemical sensors DT-1O and DT-2O were synthesized by heck reaction.They have excellent photochromic properties under UV/visible light irradiation.Moreover,the two probes showed rapid colorimetric sequential reactions to Hg²⁺/Sn²⁺.Due to the formation of the 1:1ligand/metal complex,the fluorescence intensity of the diarylethene mercury complex was significantly quenched.Interestingly,DT-1O-Hg²⁺can be further used as a new platform for rapid detection of Sn²⁺through fluorescence enhancement caused by replacing Hg²⁺.According to the"off-on-off"fluorescent switching behavior of 10,a complex logic circuit is constructed with ultraviolet/visible light,Hg²⁺/Sn²⁺combined stimulus as input and 560 nm fluorescence intensity as output.