Design,Synthesis,Fluorescence Properties Of Metal-organic Frameworks With Nitrogen,Carboxylic Acid Ligands

This paper focus on the hot research of luminescent metal-organic frameworks(LMOFs),synthesized five new luminescent metal-organic frameworks with 3D network structure under solvothermal conditions by the reaction of a series of nitrogen,carboxylic acid ligands with transition metal ion or lanthanide metal ions.Incorporation with the widely use of pincer ligands in the field of catalyst,we designed and then synthesized a novel tridentate pincer ligand.Based on the new ligand,two new MOFs have been prepared via solvothermal reaction with transition ions.The main work is as the follows:1.In this section,we selected 1,3-bis(3,5-dicarboxyphenyl)imidazolium(H4BDIZ)as the organic linkers to synthesize two isostructural MOFs with lanthanide metal ions:[Eu(BDIZ)-2H20]n(1)and[Tb(BDIZ)-2H20]n(2).We explore the luminescence properties of the two compounds through a series of characterization.We found that compound 1 exhibits selectively and sensitivity detection of 2,4,6-trinitrophenol(TNP)and Fe3+ ions in aqueous phase over other nitro-aromatic compounds and metal ions.According to the different luminescent properties of different rare earth metal ion,luminescent metal-organic frameworks(MOFs)with same structure and different metal center could be synthesized by doping with different lanthanide metals.Compound 3 would be prepared after the doping of Tb3+and the substitution of stable compound 1 to the metal center.With the doped Tb3+and Eu3+,the emission characteristic peaks of Eu shift to the emission characteristic peaks of Tb in the fluorescence spectrum.The compound was investigated as selective sensing materials for detection for nitroaromatic compounds.Then the results show that 3 exhibit selective fluorscence quenching toward TNT.2.In this part,we selected semi-rigid:4,4'-bis(pyridyl)diphenyl ether(BDPDE)and H2BDC or H2NDC as the organic linkers to synthesize two MOFs 4 and 5 via solvothermal reaction with d10 transition metal ion Cd2+.We studied the luminescence properties of the two compounds.The result shows that compound 4 have great fluorescence properties in DMF solution,exhibit high sensitively fluorescent identification for organic solvents and metal cations,especially TNP and Fe3+.3.In this section,a novel ligand with three teeth was designed and the structure and properties of the ligand was characterized in detail.Based on the new ligand,two new MOFs compounds 6 and 7 have been synthesized via solvothermal reaction with transition metal Cu and Cd.Through single-crystal X-ray diffraction,the three-dimensional framework of compounds 6 and 7 could be confirmed.