The Synthesis And Properties Of Stable MOFs Constructed Based On The Multi-site Ligand Strategy

Metal-organic frameworks?MOFs?are a class of novel materials that are self-assembled by coordination of metal ions with organic ligands.In the research of metal organic frameworks,the stability of MOFs has always been a problem to be solved for scientists.Keep the stability of MOFs in mind,a series of novel organic ligands with carboxyl group and pyridyl group as the terminal group,which are bridged by 1,3,4-oxadiazole and 4-amino-1,2,4-triazol were synthesized and characterized.The self-assembly chemistry of the synthesized ligand with different metal ions was studied.In this thesis,17 new MOFs and coordination polymers with novel structures were synthesized by hydrothermal method and diffusion method,and characterized by IR and X-ray single crystal diffraction.Also,the thermal stability,the stability in acid-base environment and the fluorescence properties of some MOFs,were studied by TGA,XRD and fluorescence spectrometer.1.One new fluorene-bridged organic ligand with 2-pyridinecarboxylic acid as terminal group was synthesized and characterized.Three novel MOFs were prepared from the above ligand and Eu?NO₃?₃,Tb?NO₃?₃,ErCl₃ salts characterized by IR and X-ray single crystal diffraction.The thermal stability and the fluorescence properties were studied by TGA,XRD and fluorescence spectrometer.One new xylene-bridged organic ligand with carboxyl as terminal group was synthesized and characterized.Two novel MOFs were prepared from the above ligand and Cd?NO₃?₂,Pb?NO₃?₂ salts characterized by IR and X-ray single crystal diffraction.The thermal stability,the stability in acid-base environment and the fluorescence properties were studied by TGA,XRD and fluorescence spectrometer.2.One new 1,3,4-oxadiazole-bridged organic ligand with 2-pyridinecarboxylic acid as terminal group was synthesized and characterized.Three novel MOFs were prepared from the above ligand and Nd?NO₃?₃,Zn?OAC?₂,Cd?NO₃?₂ salts characterized by IR and X-ray single crystal diffraction.The thermal stability was studied by TGA.3.Four new 4-amino-1,2,4-triazol-bridged organic ligand with pyridine and quinoline as terminal group was synthesized and characterized.Nine novel MOFs were prepared from the above ligand and Ag?I?,Cu?I?and Cu?II?ions characterized by IR and X-ray single crystal diffraction.The thermal stability and the fluorescence properties were studied by TGA,XRD and fluorescence spectrometer.