Synthesis And Properties Of Diarylene Fluorescence Sensor Based On N-(2-(hydrazinocarbonyl)phenyl)benzamide Unit

Compared with the traditional analysis and detection tools and instruments,the fluorescence sensor has the advantages of fast response,strong specificity,high sensitivity and easy operation,and has been widely studied and reported by a large number of researchers.Now it has been applied in various aspects of chemical analysis,environmental monitoring,and biological cell imaging.With the continuous improvement of people’s production and living standards,various metal ions are closely related to our production and life,and because of their long existence and easy accumulation in organisms,they can cause certain pollution to the environment and ecosystem.As a result,more and more fluorescent sensors are developed that can monitor metal ions in organisms and in the environment.Among the many reported sensors,the fluorescence sensor based on diarylethylene has attracted much attention due to its multi-response function with controllable fluorescence and rapid response time.Compared with other types of photochromic materials,it has more excellent photochromic properties,and has good thermal stability and excellent fatigue resistance.It has been studied by scientific and technical personnel,It is expected to become a photochromic organic molecule that occupies a certain application space in the field of fluorescence sensors.Therefore,modifying or introducing other structural molecules on the diarylethene structure to enable detection of specific analytical objects is our routine method.Generally speaking,we combine the groups with specific recognition and the structural units with multiple complexing sites and the diarylidene parent molecule through some specific connection methods to construct the corresponding diarylidene fluorescent chemical sensor.,This is by far the simplest and most effective method.N-（2-（hydrazinocarbonyl）phenyl）benzamide compounds are important precursors for the synthesis of various drugs,such as anticancer drugs,anti-inflammatory and antibacterial drugs,and various inhibitors.Moreover,it has the advantages of cheap and easy to obtain synthetic raw materials,few synthesis steps,high reaction yield,etc.At the same time,it contains more N,O atoms to provide coordination ability,which has attracted our attention.Therefore,in this paper,starting with different diarylethylene precursors to connect with the unit,designed and synthesized three new types of fluorescence sensors that respond to different metal ions,the photochromic properties of these three new types of fluorescence sensors and their response to Al³⁺,Ca²⁺/Sr²⁺and Zn²⁺were studied.the fluorescence switch performance under different conditions of stimulation,and the binding mechanism with the corresponding ions,and they have been expanded and applied.The main contents of this paper are:In Chapter 1:Briefly explained the structure and background of fluorescent chemical sensors,briefly described the characteristics of diarylethylene and its application in fluorescent sensors,briefly summarized the research progress of corresponding metal ion fluorescent sensors,and briefly introduced N-（2-（The relevant characteristics and advantages of hydrazinocarbonyl）phenyl）benzamide compounds,so the subject research of this thesis is drawn.In Chapter 2:We connected the N-（2-（hydrazinocarbonyl）phenyl）benzamide unit with the diarylethylene parent molecule containing the salicylaldehyde group through a simple Schiff base reaction.DTE-1O,a diarylethylene fluorescence sensor specifically recognized by Al³⁺.Studies have shown that its photochromic performance is good.The addition of Al³⁺can significantly increase the fluorescence of methanol solution.The photochromic performance and fluorescence response performance of DTE-1O after the action of Al³⁺have been systematically studied.According to the characteristics of the binding mechanism,the Al³⁺in the actual water sample was studied.In Chapter 3:The N-（2-（hydrazinocarbonyl）phenyl）benzamide unit and the pyridyl aldehyde structure-containing diarylethene precursor were connected by Schiff base to synthesize DTE-2O.Studies have confirmed its excellent photochromic properties and can ability to detect Ca²⁺and Sr²⁺at the same time based on fluorescence in acetonitrile and distinguished by fluorescence spectrum.In addition,the combination of Ca²⁺and Sr²⁺with DTE-2O and the fluorescent switching behavior exhibited under other conditions have been systematically studied,and they have been applied to construct molecular logic gate circuits.It has also been successfully applied to filter paper experiments,which shows its potential in fluorescent dyes,and can quickly detect Ca²⁺and Sr²⁺in the field.In Chapter 4:We synthesized the compound DTE-3O by linking the diarylethene parent with a pyridylaldehyde group but changing its left-side structure to the N-（2-（hydrazinocarbonyl）phenyl）benzamide unit.DTE-3O can specifically recognize Zn²⁺by fluorescence in methanol,and has excellent anti-interference performance.We systematically studied the mechanism of action between them and the fluorescent switching behavior under physical and chemical stimuli.It has also been applied to construct molecular logic gates and to detect Zn²⁺in actual water samples around cities,demonstrating its great application potential as a Zn²⁺fluorescence sensor.