Synthesis?structural And Properties Of Cucurbit[6]uril-based Supramolecular Complexes

Cucurbit[n]uron?abbreviated as CB[n]s?is another new type of highly symmetric macrocyclic compound that emerged after the crown ether,cyclodextrin and calixarene in the supramolecular field.Owing to its unique spatial structure and potential application value,it has been deeply concerned by researchers at home and abroad.With the development of coordination chemistry,CB[n]s supramolecular self-assembly has become a hot topic in molecular recognition,ion recognition,molecular switch,detection of nitroaromatic compounds,and identification of antibiotics.In recent years,significant progress has been made in the construction of supramolecular complexes dominated by CB[n]s.However,there are still problems in the selection of experimental conditions,such as the choice of"template agent"or"structural directing agent",solvent,metal ions and acidity and alkalinity of the solution.In this thesis,a novel supramolecular complex based on cucurbit[6]urea was synthesized under solvothermal reaction conditions.The structure of the complex was determined by means of single crystal X-ray diffraction,powder X-ray diffraction,ultraviolet-visible spectroscopy,infrared spectroscopy,fluorescence spectroscopy,thermogravimetry,etc.,and the complexes were investigated for metal cations,anions and antibiotics,nitro aromatic explosives plasma,small molecule recognition.The specific content of the paper is as follows:1.Using cucurbit[6]urea?CB[6]?as the main ligand,1,3,5-benzenetricarboxylic acid?H₃BTC?as an auxiliary ligand,and calcium chloride?CaCl₂·2H₂O?in solvothermal Under the conditions of the reaction,a novel supramolecular complex 1 was synthesized by supramolecular self-assembly.Structural analysis shows that the Ca²⁺ion of complex 1 is coordinated with seven oxygen atoms to form a seven-coordinate polyhedron,wherein three oxygen atoms are derived from the carbonyl group?C=O?in the CB[6]molecule,three oxygens.The atom comes from a coordinating water molecule,and an oxygen atom comes from a molecule of DMF.The coordination polyhedron of Ca²⁺ions is a twisted pentagonal double cone.A DMF molecule is located in the cavity of CB[6]and coordinates with a calcium atom at the port of CB[6].The nature study shows that complex 1 has obvious recognition effect on acetone solvent in common organic solvent molecules.A novel supramolecular complex 2 was synthesized by supramolecular self-assembly using sodium 2,6-naphthalene disulfonate?Na₂NDS?as a structure inducer.Structural analysis shows that supramolecular complex 2 is a one-dimensional nanotubular structure.The?-?stacking and C-H...?interaction between the carbonyl oxygen of CB[6]and the methylene or hypomethylene of the outer wall and the plane of the aromatic naphthalene ring form the supramolecular self-assembly based on CB[6]The main driving force of the body.The study of properties shows that supramolecular complex 2 has significant recognition of inorganic ions?iron ions,anions?and small organic molecules?acetone solvent,berberine,trinitrophenol?.