Synthesis And Properties Of CN~- Chemosensor Based On Schiff-base Diarylethene

Anions play an important role in biological and environmental fields.Therefore,designing and synthesizing chemical sensors that can selectively recognize anions has become a hot research topic recently.Anion sensors usually have the advantages of simple operation,high sensitivity,and good selectivity.Among many anions,cyanide ion has caused widespread concern due to its high toxicity.Even trace amounts of CN~-can cause organisms poisoning death in a short time.Therefore,it is necessary to design a sensor for rapid detection of cyanide.However,the current research of anion sensors is mainly limited by the following two aspects:one is the complex synthesis method,the other is the poor photosensitivity.Photochromic diarylethenes have shown potential application value in the fields of information storage due to their good thermal stability,fatigue resistance and rapid response.Among them,the most prominent performance is their good photosensitivity,which has been increasingly applied in molecular switches.On this basis,three different diarylethenes were synthesized by introducing specific intermediates into the diarylethenes containing hydrazine through the simplest Schiff base reaction,and their optical properties and selective recognition of cyanide ions were systematically studied.The main research contents are as follows:In Chapter one,the significance of cyanide recognition was introduced and summarized the recognition mechanism of several kinds of cyanide ion chemical sensors.It mainly includes:1.deprotonation based cyanide sensor;2.hydrogen bond based cyanide sensor;3.addition reaction based cyanide sensor;4.metathesis with the atom complexes based cyanide chemical sensors;5.coordination with metals ions complexes based cyanide chemical sensors;6.cyanide chemical sensor based on other principles.In Chapter two,a diarylethene compound 1O modified by pyridoxal was designed and synthesized.Absorption and emission spectra showed that 1O had a specific recognition of cyanide,and its optical properties were characterized.The combination method was studied by nuclear magnetic and mass spectrometry,and it was found that the cyanide caused the deprotonation effect of the hydrogen of the phenolic hydroxyl group to produce a color reaction.In Chapter three,a diarylethene compound 2O modified by2-amino-6-chloro-3-formyl chromone was designed and synthesized.Absorption and emission spectra show that 2O can selective recognition of cyanide ions,while F~-has slight interference,but it does not affect the recognition of CN~-.The binding mode was studied by~1H NMR and Mass spectrometry.It was found that the cyanide made the hydrogen of the imine undergo the deprotonation effect and the color reaction.In Chapter four:a diarylethene compound 3O modified with5-allyl-3-methoxysalicylaldehyde was designed and synthesized.The absorption and emission spectra show that 3O has a specific recognition of cyanide ions without any other interference.Its optical properties were characterized.The binding mechanism was studied by~1H NMR and Mass spectrometry.It was found that the color change of cyanide was caused by deprotonization and nucleophilic addition reaction.Finally,we have successfully applied in actual water sample and cell imaging.