Construction Of Cucurbit[6]uril Based Supramolecular Fluorescent Probes For The Detection Of Moleculars/ions

With the development and deepening of supramolecular chemistry,it involves an extremely wide range of fields.Among them,cucurbit[n]uril（CB[n]s）molecules,as an important member of supramolecular chemistry,play an important role in environmental pollution analysis and detection due to their unique rigid structure,simple synthesis methods,and inexpensive synthetic materials.The large-scale discharge of factory production residues and industrial wastewater,which generates pollutants（molecules/ions）,can cause serious ecological problems and affect public environmental health.Most traditional detection methods have problems such as high cost,time-consuming,and cumbersome operations,making it difficult to meet the needs of detecting multiple pollutants.This article uses solvothermal method was developed for the synthesis of cucurbit[6]uril with 8-Aminonaphthalene-1,3,6-trisulfonic acid disodium salt（Na₂ANS）and8-Hydroxyquinoline-5-sulfonic Acid（HQDS）as the main ligands,two novel CB[6]-based supramolecular complexes have been successfully synthesized.The structure was characterized by single crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,fluorescence spectrum and scanning electron microscopy,the recognition of organic pollutant molecules（antibiotics,nitro compounds）and metal ions（cations,anions）by two Supramolecular assembly as fluorescent probes was also studied.The specific contents of the thesis are as follows:1.[Na₂K₂（CB[6]）₂（ANS）₂]·4H₂O（1）Using Na₂ANS as structure guide with the participation of Na⁺and K⁺,a novel supramolecular complex 1 based on CB[6]was successfully synthesized.The structural analysis showed that two CB[6]molecular ports were formed by the ligand of two K⁺[（CB[6]）₂-（K）₂]₂,and[（CB[6]）₂-（K）₂]₂ and ANS^2-were connected by Na⁺.The results of fluorescence analysis indicated that complex 1 can be used as a fluorescence probe to realize nitro compounds 2,4,6-trinitrophenol（TNP）and heavy metal cation(Ba²⁺)sensitively and rapidly,with limits of detection（LOD）were 0.013、0.14μM,respectively.At the same time,it has been used for the detection of TNP and Ba²⁺in real lake water samples,and has a good recovery rate.The security pattern of complex 1 was successfully prepared to realize the visual detection of TNP/Ba²⁺.2.[Cd（QDS）₂]·CB[6]₂（2）Using HQDS as the structural directing agent and Cd²⁺as the central ion,a novel supramolecular complex 2 based on CB[6]was successfully synthesized.Structural analysis shows that in the structure of complex 2,Cd²⁺coordinates with four oxygen atoms and two nitrogen atoms,where the oxygen atoms come from two HQDS molecules and two water molecules,resulting in a six coordinated twisted polyhedral geometric structure.Studies on the fluorescence properties of complex 2 have shown that as a fluorescent probe,it efficiently detects nitroaromatic explosives 2,4,6-trinitrophenol（TNP）and 4-nitrophenol（4-NP）,furan antibiotics Nitrofurazone（NFZ）and Nitrofurantoin（NFT）,and anions(Cr₂O₇^2-,Mn O₄^-)with detection limits were 72、74、113、132、95、89 ppb,respectively,and exhibits excellent selectivity and sensitivity.