Synthesis And Host-Guest Recognition Properties Of Double-Arm Hydrazone Supramolecular Compounds

Supramolecular functional materials are new materials based on weak intermolecular interactions In recent years,supramolecular functional materials have been widely concerned by researchers because of their good stimulus response,self-repair,biocompatibility and other advantages.Metal ions and anions have always played an important role in biological systems and production activities.At present,common ion detection methods usually require complex operations and expensive instruments.therefore,the development of metal ion and anion detection methods with high sensitivity,high selectivity,rapid response,simple operation and low cost is of great significance to ecological stability and human health.Based on the development of supramolecular chemistry,we introduce Hydrazone group into supramolecular sensor to provide good coordination ability,and design the target sensor with double-arm structure,through the synergistic action of benzene ring,naphthalene ring and Hydrazone group in the double-arm structure,realize the highly sensitive and selective detection of anions and metal ions,which provides a new idea and method for supramolecular colorimetric/fluorescence sensors to identify metal ions and anions.This paper will be divided into four parts to discuss the preparation and host-guest recognition performance of Hydrazone supramolecular sensors.1.Research progress of supramolecular sensors and their application in ion recognition in hydrazone derivatives:The significance of ion recognition research and the latest research progress of metal ion and anionic sensors are introduced;Overview of aggregate induced Luminescence（AIE）and research progress of AIE sensors;Research progress of ionic sensors containing hydrazone;Subject proposal and research content.2.The fluorescence sensor BNH was synthesized by the reaction of 1,4-phthalaldehyde and 1-naphthylacetylhydrazine.The sensor shows good AIE performance in DMSO-H₂O mixed solution.In addition,BNH can achieve sensitive single detection of Fe³⁺in the mixed solvent of DMSO-H₂O（V/V=1:1）,so that the blue fluorescence of BNH under 365nm fluorescence is quenched,and the detection limit is 4.46×10^-7M.The recognition process is basically not affected by other metal ions.Interestingly,in the mixed solvent of DMSO-H₂O（V/V=1:1）,F^-and H₂PO₄^-can reopen the fluorescence of BNH-Fe³⁺,and the detection limits are 2.21x10^-6 M and 2.20x10^-6 M,respectively,thus realizing the continuous recognition of Fe³⁺and F^-/H₂PO₄^-.We also show the supramolecular force in the process of BNH recognition of Fe³⁺by quantitative calculation,which can also support our proposed recognition mechanism.3.A colorimetric sensor BPFH based on pentafluorophenyl hydrazone was synthesized by the reaction of 1,4-phthalaldehyde and Pentafluorophenylhydrazine.BPFH can realize the single recognition of F^-in DMSO,and it is observed that the solution of BPFH changes from colorless to pink under natural light.Through calculation,the detection limit is 1.63×10^-7M.Through ¹H NMR titration and FT-IR experiments,the results show that BPFH recognizes F^-by hydrogen bond and anion-πinteraction.The theoretical calculation results also support the mechanism obtained by the experiment,which provides a new method with easy operation and strong visualization for the identification of F^-.4.Based on the fact that the sensor BPFH can selectively recognize F^-,we have developed a supramolecular colorimetric sensor BPFH-F which can selectively recognize Ag⁺.Under natural light,the sensor BPFH-F in DMSO appears pink,and when Ag⁺is added,the solution changes to yellow.Through the strong affinity of BPFH-F to Ag⁺,we provide a convenient,selective,sensitive,and visible detection method for Ag⁺.The detection limit is calculated to be 1.99×10^-7M.