| Metal-organic frameworks?MOFs?are coordinational networks containing potential voids and organic ligands,which are usually constructed by inorganic metal ions and organic linkers through coordinational bonds.Due to their diverse structures and functionalized pores,MOFs have important potential applications in the fields such as adsorption,separation,sensing,and optics.With the aim to design novel MOFs with expected properties,we have synthesized the semi-rigid organic ligand 5,5',5''-?1,3,5-triazine-2,4,6-triyl?tris?azanediyl?triisophthalate?H6TATAT?.Five MOFs crystal materials have been constructed by the coordination of H6TATAT with d10 transition metal ion and lanthanide ions(Ln3+),considering the following merits of H6TATAT:?1?the H6TATAT molecule can form chiral conformations by rotating flexible imino groups,which favors to synthesize chiral MOFs using the achiral ligand;?2?the triazine ring and imino group N atoms in the H6TATAT molecule are potential Lewis basic sites,thus the MOFs constructed by the H6TATAT are candidates to adsorb and detect Lewis acids through the Lewis acid-base interaction;?3?the H6TATAT molecule has highly conjugated systems and photoluminescence properties,which can coordinate with d10 transition metal ions or lanthanide ions to form luminescent MOFs.The main works of this thesis are as follows:1.The chiral Zn-MOF,[?CH3?2NH2]5[Zn1.5?Zn3O??TATAT?2]·9DMF·17H2O,has been constructed by H6TATAT and d10 transition metal Zn2+.Based on the selective chiral symmetry breaking,we have obtained a non-random handedness excess of Zn-MOF?Zn-MOF-P>>Zn-MOF-M?using achiral raw materials.This phenomenon is found and confirmed by single-crystal X-ray diffraction and solid-state circular dichroism spectroscopy.In addition,the Zn-MOF exhibits ligand-based light emission and displays high selectivity and sensitivity for luminescence detection of Fe3+and nitro explosive molecules?especially3-nitrophenol?.2.Four isostructural anionic Ln-MOFs,[?CH3?2NH2]1.5[Ln1.5?TATAT??H2O?4.5]·x?solvent?(Ln3+=Tb3+,Eu3+,Dy3+,and Gd3+),have been formed by H6TATAT and lanthanide ions.The surface of the two channels?window sizes:8.9×8.9?and 4.3×4.3??in the Ln-MOFs has exposed Lewis basic N sites.The anionic framework properties of Ln-MOFs enable them to selectively adsorb and separate cationic dyes?such as methylene blue?by cation exchange.Tb-MOF and Eu-MOF can be used for naked eye detection and identification of ethanol,acetonitrile and diethyl ether via solvatochromism.In addition,the Ln-MOFs have excellent luminescence properties.Among them,Tb-MOF shows highly selective luminescence sensing Co2+ion. |
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