Synthesis And Properties Of Fluorescence Sensor Based On Hydrazine Hydrate-diarylethene

With the development of modern industry,increasing industrial emissions containing metal ions have caused serious water pollution,which affects food and agriculture and further threatens human health and the environment.Therefore,qualitative and quantitative analysis of various ions have received considerable attention.So far,although there are many methods to detect ion,but in many metal ions detection method of fluorescent chemical sensor since it has advantages of high selectivity,high sensitivity and real-time detection,has attracted much attention in the field of environmental research and analysis.In the past years,large numbers of photochromism compounds have been reported for ions detection.Photochromic diarylethenes are considered as the most promising photo-switchable molecules on account of their prominent thermal stability,excellent fatigue resistance,and fast response.Under the stimulation of light or chemical substances,the ultraviolet or fluorescence spectrum of the diarylethene compounds will change,which will cause the color change.Therefore,it is applied in the fields of chemical sensing or light control switch.Up to now,some specific functional groups have been introduced into diarylethene,and many sensors have been synthesized for ion detection,which has aroused the interest of many researchers.Hydrazine hydrate was used to detect metal ions,because it was easy to contract with many compounds containing aldehyde groups,and the nitrogen atoms in hydrazine hydrate had lone pair electrons that were easy to coordinate with many metal ions.In this paper,three new diarylethene compounds were synthesized by connecting intermediates with aryl derivatives in a specific way,the photochromic properties,fluorescence switching properties and ion responsiveness of these three compounds under external stimulation in a specific solution were investigated.The main research contents of this paper are as follows:1.The pyrene hydrazine structural unit was connected with the diarylethene in the form of schiff base to obtain the compound DTE-1O.It was found that compound DTE-1O had better photochromic and fluorescence switching properties in acetonitrile solution,and could efficiently and sensitively recognize and distinguish Cd²⁺and Zn²⁺,so it could be used as a fluorescence sensor to recognize Cd²⁺and Zn²⁺.2.DTE-2O was synthesized by connecting pyridazine-hydrazine structural units with diaryl ethylene in the form of schiff base.The ultraviolet and fluorescence properties of compound DTE-2O in acetonitrile:water=9:1 solution were studied.It can selectively recognize Cd²⁺and Zn²⁺,and can be used as a fluorescence sensor to recognize Cd²⁺and Zn²⁺.3.DTE-3O was prepared by linking the diarylethene of hydrazone unit of salicylaldehyde with schiff base.Studies have shown that compound DTE-3O can specifically identify Al³⁺in methanol solution and has good anti-interference,and is almost unaffected by any other ions.It can also be effectively regulated by UV/Vis and Al³⁺/EDTA,which can be used as a specific fluorescent sensor to identify Al³⁺.