The Synthesis, Characterization And Properties Of Metal-organic Frameworks

In recent years, metal-organic frameworks (MOFs) have been attracted intense attention due to their promising properties and great potential applications in the fields of luminescence, magnetism, gas separation/adsorption, catalysis,,and optical properties and their fascinate topologies. How to explore the nature of metal-organic frameworks at the molecular level, and apply them to design and synthesize metal-organic frameworks crystalline materials possessing specific structures and physicochemical properties, further achieve controllable configurations and properties, is significant theme in this field. In this study, four complexes with different kinds of ligands was synthesized and characterized with IR,TG, luminescence and X-ray diffraction. Here are the results:By reacting a flexible tripod ligand,5-(4-(1H-tetrazol-5-yl) phenoxy)isophthalic acid(H3L) with cadmium chloride, we got a new complex{[Cd2L(OH)(H2O)]-2H2O}n, X-ray diffraction crystal structural analysis reveals its crystallizes in triclinic space group of P-1.The adjacent Cd(1) and Cd(2) were connected by μ3-hydroxide anion to form a tetranuclear Cd. The tetranuclear Cds were joined by the ligands to form a3D structure. The complex1exhibits a broad emission band with the maximum intensity at435nm (λex=365nm)By reacting zinc fluoride with isonicotinic acid, we had complex2,[Zn3(Int)2F4]·CH3OH·H2O, The unusual F-ions pillared structure of1exhibits a porous three-dimensional network with a pcu topology. The fluorescent characterization indicates that it is an n excellent candidate for fluorescent materials.By reacting2,2’-bipyrimidine,4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione and rare earth, we got two novel complexes which were binuclear. They formed to one-dimensional chain with hydrogen bonds. Further, they joined together to form a3D framework with Vander Waals force. The luminescent testing shows the complexes are good for red fluorescent materials.In a word, the obtained outcome of this dissertation not only enriches the contents of crystal engineering and materials chemistry, but also provides a new idea and consulting effect to design and prepare metal-organic frameworks crystalline materials with diverse networks and especial properties.