Design And Assembly Of Metal Organic Frameworks Containing Carboxyl Ligands And The Studies Of Luminescent And Catalytic Properties

The metal-organic frameworks（MOFs）compound is a special crystal material with porous structure,which formed by self-assembly of metal ions and organic ligands.Due to the variety of species,the coordination of the channels and the ease of functional structures,it has wide application prospects in gas storage,asymmetric catalysis,separation,magnetic force,fluorescence sensing and so on.In this paper,we designed and synthesized two kinds of carboxylic acid ligands with two different functions,these ligands were further coordinated with different transition metal ions.Six kinds of unrefined porous metal organic frameworks were obtained,are respectively discussed the fluorescence sensing and asymmetric catalysis.Mainly divided into the following two parts:1.In this part,we designed and synthesized a dicarboxylic acid tetramethylsyrene ligand（H₂L1）by using tetramethylsyrene with AIE effects.Meanwhile,the ligand could form a strong luminescent 3D metal organic skeleton compound Zn₄O（L1）₃（I）by coordinating with Zn（II）.Properties such as the X-ray single crystal diffraction,gas desorption,fluorescence properties and thermal stability were studied.The results show that complex I has a microporous structure and its solid absolute quantum yield is 30.0%,which is slightly higher than that of ligand fluorescence quantum yield of 22.0%.Fluorescence sensitivities showed that the volatile organic compounds such as toluene,m-xylene,mesitylene and aniline had a fluorescence enhancement effect on complex I,and nitrobenzene had a fluorescence quenching effect on complex I and a quenching rate of over 95%.2.In this paper,four polycarboxylic acid organic ligands（H₃L2-boc,H₃L2,H₂L3 and H₄L4）containing L-pyrrolidine chiral groups and their five kinds of chiral porous MOFs:[Zn₄O（L2-boc）₂]（II）,[Fe₂CoO（L2）₂]（III）,[Zr₆O4（OH）₄（L3）₆]（IV）,[Zn₄O（L3）₃]（V）and[Cu₂（L4）]（VI）had been synthesized and characterized by IR,NMR,SCXRD,PXRD and thermogravimetry.The catalytic properties of complexes II,III and IV on the asymmetric aldol reaction of cyclohexanone and p-nitrobenzaldehyde were carried out.The experimental results show that the yield of aldol reaction catalyzed by complexes II,III and IV is 51-73%.In contrast to the catalytic effect of L-pyrrolidine derivatives or MOFs containing L-pyrrolidine,the configuration of yield catalyzed by II,III and IV was dominated by cis.The complex IV is subjected to a secondary cycle,which can be reused as a heterogeneous catalyst,and the selectivity of the catalytic product is higher（dr=99:1）.