Design,synthesis And Properties Of CN~-probe Based On Diarylethene Derivative

Cyanide（CN^-）is a highly toxic anion that is very harmful to human health,but very useful in industrial activities.Therefore,it is urgent to design an efficient and reliable cyanide detection strategy.The chemical dosimetry method is an efficient and selective method for identifying a specific analyte because of its high sensitivity and rapid reaction.The chemical reaction between the molecule and the specific analyte induces an important chemical transition by breaking or forming several covalent bonds,resulting in the observation of changes in absorption wavelength and solution color.Thus,chemical dosimetry methods for colorimetric use require only inexpensive equipment,or no equipment at all,since changes in color can be detected by the naked eye.The observable signal is irreversible and exhibits a cumulative response directly related to analyte concentration.In recent years,chemical dosimetry has attracted wide attention because of its superior detection performance.Due to its unique nucleophilic properties,nucleophilic addition reactions occur between CN^-and the corresponding reactants,such as cyanoalcohol formation,dicyanvinyl-addition,Michael addition,and indole or pyridine addition.The nucleophilic attack of CN^-disrupts electron conjugation,thus altering absorption and fluorescence emission properties.However,as far as we know,these addition reaction processes are based on the structural changes of reactants,and have some shortcomings such as complex synthesis process,weak anti-interference ability and slow sensing speed.Diarylethylene compounds have been paid much attention by researchers because of their remarkable photochemical reactivity,thermal stability and fatigue resistance.Since different groups can be attached to the sides of a diarylvinyl-ethylene compound,the structure and properties of the diaryl-vinyl-ethylene molecule are diverse.Photochromic compounds,as a typical photoswitching unit,have advantages in the recognition of state and sensing information as sensors,thus providing opportunities for the realization of multiple detection of cyanide anions.To date,few vinyl-containing diaromatic ethylene derivatives have been reported for the detection of CN^-.Therefore,in this paper,we designed and synthesized three diaryl vinyl compounds for the detection of CN^-and systematically studied their sensing properties.The specific work of the thesis is as follows:1.In the first chapter,the basic properties and applications of diarylethylene compounds are introduced,and the applications of diarylethylene compounds in three aspects of sensors are emphatically introduced.Since we will study the sensing performance of CN^-,then introduce the research progress of CN^-,finally put forward our topic.2.In the second chapter,we designed and synthesized the diarylethylene compound 1o containing barbituric acid structure.The structure of the compound was characterized by ¹H NMR,¹³C NMR,Mass Spectrometry and other techniques.Then we studied the photochromic properties of 1o in DCM system and its sensing properties to CN^-.The response mechanism was confirmed by NMR titration.3.The third chapter,diarylvinyl compounds containing cyanoethylene structure were designed and synthesized.Due to the concentration effect of 1o,the aggregation fluorescence quenching will occur,thus limiting its application.Therefore,we designed and synthesized the diarylvinyl compound 2o containing cyanoethylene,which solves the above deficiencies well and can realize multiple responses to CN^-in DMSO system.With fast response speed,high sensitivity,low detection line and other advantages,we have successfully used it to detect actual water samples and food.4.The fourth chapter,a diaryl vinyl compound containing imine coumarin was designed and synthesized.We change the diaryl ethylene parent with aldehyde into a diaryl ethylene parent with salicylic aldehyde,and allow the cyanoethylene part to combine with the hydroxyl group to produce imine coumarin,and study the photochromic properties of its DCM system and the sensing properties of CN^-.