The Preparation And Performance Of MOFs Functional Materials Based On Nitrogen-rich Ligands

Metal-organic frameworks?MOFs?are recognized as one of the most important porous materials,with unique properties and chemical versatility.However,most MOFs have relatively poor stability,which limits their practical applications.Therefore,building stable MOFs have become a research hotspot.In this thesis,stable MOFs were designed and synthesized under solvothermal conditions,mainly using nitrogen-rich ligands and transition metals.The X-ray single crystal diffractometer was used to characterize its coordination environment and spatial structure,and the photoluminescence spectrum was used to characterize the optical properties of the material.In addition,this MOFs material was also tested by UV-visible absorption spectrum and infrared absorption spectrum,and the thermal and chemical stability of MOFs were further researched by means of thermogravimetric analyzer and X-ray diffraction analyzer.The main tasks are as follows:?1?A new two-dimensional?2D? stable cadmium-organic framework,[Cd?btca??2,2'-bpy?]n?1?,has been successfully designed and synthesized by means of solvothermal method?where H₂btca = benzotriazole-5-carboxylic acid,2,2'-bpy = 2,2'-bipyridine?.Complex 1 has been characterized by combining single-crystal X-ray diffraction analysis,elemental analysis and IR spectroscopy.Single-crystal X-ray diffraction analysis reveals that 1 possesses 2D wave-like layered structure,and these 2D wave-like layers are interlinked each other by ?-? stacking interactions to form supramolecular network.Compound 1 is especially stable in air,water,acidic/basic aqueous solutions?p H = 1-13?and common organic solvents.Furthermore,MOF 1 is stable up to 460 °C.Therefore,Compound 1 possesses excellent chemical and thermal stabilities,which makes it possible for practical applications.In addition,the optical property of the complex 1 was investigated.?2?A simple two-dimensional structure of [Zn₂?L?₂?bpzb?]_n?2?was synthesized by using 9H-carbazole-3,6-dicarboxylic acid?H₂L?,1,4-di?1h-pyrazol-4-yl?benzene?H₂bpzb?double ligands and transition metal Zn ion.The structure was analyzed by X-ray single crystal diffraction technology.X-ray single crystal diffraction shows that Compound 2 has a two-dimensional layered structure.These two-dimensional layered structures form a 3D supramolecular framework by AA stacking.