The Synthesis And Properties Of A Series Of Novel Cyanide Anion Receptors Containing P-Hydroxyphenol Chalcone

The design,synthesis,and spectral analysis of anion receptors is one of the important contents of anion qualitative and quantitative detection,and it is the frontier science of supramolecular chemistry.Since cyanide ion is extremely toxic,it is easily absorbed by humans or animals through various routes such as muzzle,respiratory system or skin.It affects the blood vessels,nerves,and vision of the human body and is classified as level6 toxic.CN^-is extensively used in various industrial activities,such as fiber fabrication,production of medicine and pesticide,gold mining,,electroplating,and metallurgy,which is great harmful to biology and environment.The World Health Organization?WHO?stipulates that the concentration of cyanide in drinking water does not exceed 1.9×10^-6mol·L^-1.The methods for the detection of CN^-such as chromatographic,electrochemical,chemical titration flow injection analysis,voltammetry have been reported.The colorimetric method/UV-Vis absorption spectrometry has attracted more and more attention due to its advantages such as simplicity,high selective,real-time and visual detection,and are inexpensive.Therefore,the design of simple,highly selective,fast response,and highly sensitive cyanide ion receptors has become a hot spot in the current scientific research.Based on the above reasons,this thesis designed and synthesized a class of cyanide anion receptor molecules containing phenolic hydroxyl chalone,in which the phenolic hydroxyl group serves as the recognition site.The anion recognition performance was investigated using"naked eye"recognition and spectroscopic techniques.The receptors have the characteristics of simple synthesis,fast response and high sensitivity.The results mainly include the following five parts:Chapter 1:This chapter introduces the meaning of supramolecular chemistry and its research content in host-guest chemistry.The source,application and toxic effects of cyanide ions.The research about cyanide anoion receptors in recent years were reviewed according to the recognition mechanism of cyanide anoion receptors such as deprotonation,hydrogen bonds,addition,metathesis with the atom complexes,and other recognition mechanism.The current situation and progress of related research about CN recognition and detection at home and abroad were summarized.Based on the review of the entire literature,the design ideas and research methods of the thesis project were proposed.Chapter 2:Three kinds of chalcone receptors containing p-hydroxyphenol,p-BHR₁,p-BHR₂,and p-BHR₃,were designed and synthesized,and were verified by ¹H-NMR and¹³C-NMR.The anonic response of the three reception in acetonitrile-water?9:1,v/v?were investigated,they show specific recognition toward CN^-over other anions including F^-,Cl^-,Br^-,I^-,AcO^-,HSO₄^-,H₂PO₄^-,and NO₃^-.When CN^-is gradually added to the receptor solution,a distinct change in color from colorless to yellow was immediately observed.The interaction between the receptors and CN^-and limit of detection?LOD?were investigated using titration method.The receptor p-BHR₃ shows a low limit of detection(1.01×10^-6 mol·L^-1).The recognition mechanism and the stoichiometry between receptor and CN^-was determined using a Job'plot and NMR titration.Chapter 3:Two kinds of chalcone receptors containing p-hydroxyphenol and pyridine?p-HPPR₁ and p-HPPR₂?were designed and synthesized.After addition of CN^-in the 10%aqueous ethanol solution of the receptor,the UV-Vis absorption intensity at around 325 nm decreased,and a new strong UV-Vis absorption appears at 404 nm.A color change from colorless to yellow or orange was simultaneously observed upon the addition of CN^-.Unobvious change was observed upon the addition of other anions.The LOD was measured to be 1.50×10^-77 mol·L^-1 by UV-Vis titration.¹H NMR titration shows that the interaction mechanism between receptor and CN^-is deprotonation and intramolecular charge transfer?ICT?.Because of the receptors have the characteristics of simple synthesis,fast response and high sensitivity,the receptors were applied to the rapid detection of CN^-in four kinds of samples water and the functions of logic gates.Chapter 4:Two kinds of anion receptors p-HPPBR₁ and p-HPPBR₂ containing p-hydroxyphenol and pyridine bromide were designed and synthesized.After the addition of CN^-in the acetonitrile-water?19:1,v/v?solution of the receptor,both UV-Vis spectrum and"naked eye"observations showed that the acceptor can selectively recognize CN^-,and the solution changed from colorless to red and blue.The LOD was calculated to be8.20×10^-77 mol·L^-1 and 5.10×10^-77 mol·L^-1.¹H NMR titration shows that the interaction mechanism between receptor and CN^-is deprotonation.Because the receptors have the advantages of rapid response,high sensitivity,and obvious discoloration,the receptor was applied to the rapid detection of CN^-in four kinds of samples water and the functions of logic gates.A test strip containing receptor was also prepared for the rapid detection of CN^-in real water samples.Chapter 5 Summary and outlook.Seven novel CN^-colorimetric receptors have been synthesized and verified.The selectively recognition and mechanism of receptors for cyanide ion were studied by UV-Vis spectroscopy and nuclear magnetic titration.At present,the hydroxyl group-containing CN^-receptor is greatly affected by pH and can only develop color within a certain range of acid and alkalinity,and the solvent requirements are stringent.Researches on CN^-colorimetric receptors mainly focus on the research of responsiveness,and the development of response materials is lagging behind.However,it is rare to apply the fast and convenient CN^-recognition material to the actual samples.This study will provide new ideas for the development of an easy-to-use,fast,efficient and economical CN^-detection material.