Synthesis And Fluorescent Property Investigations Of Metal-Organic Complexes Based On Aromactic Carboxylic Ligands

Metal-organic frameworks?MOFs?as a younger junior among porous materials,are receiving more and more people's attention,mainly because it has unique properties and structural characteristics when comparing to the traditional porous materials,such as high specific surface area,and easily regulatory skeleton structures and pore structures.The unique properties of MOFs make them exhibit potential applications in the gas adsorption and separation,catalysis,thin film devices,magnetic and fluorescent identification and so on.Because of the recent national security and environmental concerns,the metal-organic frameworks have attracted wide attention in fluorescence recognition.Hence,construction of fluorescent metal-organic complexes have always been one of the most important research directions in this field.In this thesis,the fluorescent metal-organic complexes were designed and synthesized by the introduction of metal ions with fluorescent emission function.Eight novel MOFs were obtained by self-assembly of H₄L¹,H₂L²,H₃L³ and Zn²⁺with d¹00 electronic configuration or lanthanide metal ions(Tb³⁺,Dy³⁺,Gd³⁺,Tm³⁺),and characterized by X-ray diffraction,XRD,thermal analysis,infrared and luminescent spectroscopies.For some MOFs with ideal and stable structures,we also focus on the investigations in their fluorescent recognition properties.The main contents of this thesis include the following points:1.Four new metal-organic complexes?1-4?with isomorphism were synthesized by using H₄L¹ ligands and lanthanide ions(Tb³⁺,Dy³⁺,Gd³⁺,Tm³⁺).Since complex 1 shows a clear characteristic peak of Tb³⁺,we also investigate its fluorescent sensing for small organic molecule,metal cations and nitroaromatic compounds.The results show that the complex 1can quickly identify nitroaromatic compounds,especially for 4-NP.2.Four porous metal-organic complexes?5-8?were synthesized by the self-assembly of organic ligands?H₂L²,H₃L³?and Zn²⁺under different conditions,and characterized by X-ray diffraction,XRD,TG,IR,solid-state fluorescence characterization.In this chapter,we focus on the study of the adsorption properties and the fluorescent sensing for the metal ions and nitro-containing aromatic compounds by complex 5.The results show that complex 5 not only has moderate selectivity for Fe³⁺,but also can quickly identify nitrophenol?4-NP?and dinitrophenylhydrazine?4-NPH?.