Design, Synthesis And Properties Of Functionalized Metal-Organic Framework

Metal-Organic Frameworks(MOFs)are a kind of crystalline porous solid materials,constructed from discrete inorganic and organic second building units(SBUs),having the advantages of high porosity,diversity structures and adjustable pores.In recent years,scientists have constructed a series of functionalized MOFs materials from a combination of different types of activity sites,such as metal nodes,functional organic ligands and guests in the porous framework.These functionalized MOFs materials have been widely used in multiple research areas,including gas storage,gas separation,catalysis,sensors,biological imaging,drug delivery,etc.Nowadays,the strategies for constructing functionalized MOFs materials mainly include prefunctionalization approach and post-modification approach.In this thesis,by taking advantage of prefunctionalization approach,three functionalized MOFs materials have been successfully synthesized.Moreover,their potential applications in the adsorption and transformation of CO2,iodine adsorption and dye adsorption have also been investigated,respectively.In the first part of this thesis,two different types of amino functionalized MOFs structures,which belong to Ui O-67 type and bio-MOF-1 type respectively,have been constructed from three different ligands,named L1,L2 and L3.After a series of basic characterization,bio-MOF-1-NH2 and Ui O-67-MIX-0.7-NH2 were selected to study their capacity for the adsorption of CO2 because they had higher porosity than other MOFs.Furthermore,they were both used to catalyze the synthesis of cyclic carbonate from epoxides and CO2,associated with tetrabutyl ammonium bromide(TBAB).It was found that both of them had good catalytic performance,including accelerating the reaction rate,good universality of substrates and recycling for more than five times.In the second part of this thesis,a dual-functionalized MOF named Ui O-67-MIX-0.7-NH2,which contained both amino and pyridine groups,was constructed by using multiple ligands.Then,its capacity for iodine adsorption was studied by various methods,including selecting the most suitable solvents,calculating the maximal adsorption capacity,testing dynamic adsorption curve and adsorption kinetics,attempting adsorption and desorption recycles,and speculating the adsorption mechanism.It was found that the maximum adsorption of iodine was 301.6 mg/g(MOF),and its adsorption dynamics was in accord with Pseudo-second-order-model.Additionally,due to the high stability of the structure,Ui O-67-MIX-0.7-NH2 could be reused for several times.In the third part of this thesis,by combining a calix[4]arene dicarboxylic acid ligand with cadmium ion and zinc ion,respectively,two new MOFs,named Cd-calixarene-MOF-I and Zn-calixarene-MOF–II,were constructed.Single-crystal X-ray analysis shown that both of them were 2D mesh structure.Furthermore,due to the high stability in water,these two MOFs were employed for the adsorption of dye molecules in water.It was found that both of them exhibited good surface adsorption for methylene blue,and the maximum adsorption capacity of MB in Cd-calixarene-MOF-I was higher than Zn-calixarene-MOF-II.