| Metal-organic frameworks?MOFs?are a class of promising crystalline microporous materials usually formed by self-assembly of metal ions/clusters and bridging organic ligands with functional groups via coordination bonds and weak interactions.In past few several decades,they have attracted great interest of scientific research workers,not only because of their fascinating structures,but also owing to their tremendous potential applications,such as magnetism,gas storage/separation,,fluorescence,ion exchange and catalysis,and so on.Due to their high specific surface area,high porosity,structure and functional diversity,this paper mainly studies their applications in adsorption,solid state luminescent,and fluorescence sensing.In this article,the author choosed 2-?1H-1,2,4-triazol-1-yl?terephthalic acid?H2L?as organic ligand to construct MOFs by reacting with transition metal?Zn?II??and lanthanide metal ions.Under the solvothermal reaction,eight MOFs have been successfully constructed:{[Sm?L?1.5?H2O?]·4H2O}n?1?,{[Eu?L?1.5?H2O?]·4H2O}n?2?,{[Gd?L?1.5?H2O?]·4H2O}n?3?,{[Tb?L?1.5?H2O?]·4H2O}n?4?,{[Dy?L?1.5?H2O?]·4H2O}n?5?,{[Zn?L?]·DMA}n?6?,[Zn?L??H2O?]n?7?,and{[Zn?L??bpe?0.5]·3H2O}n?8?.Their structures have been determined by X-ray single crystal diffraction,and their properties of powder X-ray diffraction?PXRD?,infrared spectra?IR?,thermogravimetry?TG?and elemental analysis?EA?have been studied,and the fluorescence performance of 1-7 has been tested focusedly.This paper is consisted of three chapters as follow:In the first chapter,firstly,a brief overview of the concept of MOFs is given;secondly,the applications of MOFs are introduced;finally,the purpose and significance of this thesis are summarized.In the second chapter,we introduces the structure and basic properties of five isomorphic Ln-MOFs based on H2L and rare earth metal salts?Sm,Eu,Gd,Tb,Dy?.The fluorescence properties of the complexes 1-5 were tested and studied,the fluorescence sensing properties of complex 4 are mainly studied because of its extremely high quantum yield and excellent green light,and the mechanism of luminescence and quenching have been studied in depth.Interestingly,the isomorphic 2 and 4 were doped,and then a series of bimetallic doped Eu/Tb-MOFs were obtained,which realized the tuning of luminescent color for bimetallic doped Eu/Tb-MOFs.In the third chapter,we introduces the structures and basic properties of three Zn-MOFs constructed by H2L and Zn2+ions under the solvothermal reaction.The compound 6 is a three-dimensional framework containing binuclear paddle-wheel zinc clusters.The structure of 6 has one-dimensional rhombic channels decorated by open N-donor sites,which provide conditions for gas storage and separation.Therefore,we studied the adsorption properties of 6for N2,H2,CO2 and C1/C2/C3 alkanes.The solid fluorescence properties of 6 and 7 were also characterized and analyzed,compared to H2L,6 blue-shifted more than 7.The compound 8 is constructed by introducing 1,2-bi?pyridin-4-yl?ethene,which is a three-dimensional framework of 2-fold interpenetrating.In addition,the author studied the effects of auxiliary ligand?1,2-bi?pyridin-4-yl?ethane?and solvents on the configuration of the main ligand H2L and crystal structure.In the last part,the author summarizes the thesis briefly. |
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