Synthesis And Properties Investigation Of Methyl And Amino Functional Metal-organic Frameworks

As an emerging class of highly ordered crystalline porous materials,metal–organic frameworks?MOFs?have become a new research hotspot in chemistry and materials science during the last few decades,which is mainly attributed to their exceptionally high surface area,tunable pores,as well as intriguing functionalities.When compared to traditional zeolites and carbon-based porous materials,MOFs perform excellently in potential various applications,such as greenhouse gas adsorption and separation,energy gas storage,fluorescent probes,asymmetric catalysis in the domain of the space limit,transfer of drug molecules and molecular magnetic.Design and synthesis of functional MOFs is particularly important to better implement application of MOFs in these areas.In this thesis,we focus on the design and sythesis of organic ligand,by carefully selection reaction conditions and using post-synthesis modification successful synthesis of the ten metal-organic frameworks.The structures and properties of the MOFs are characterized by X-ray single crystal diffraction,elemental analysis,thermogravimetric analysis and infrared analysis,X-ray powder diffraction and gas adsorption test.The main contents include the following points:?1?Methyl functionalization.Using methyl steric hindrance effect of two kinds of non coplanar fragrance four carboxylic acid ligands H₄L¹ and H₄L²,self-assembly with Cd²⁺got complexes 1 and 2.Complex 1 is a 2-dimensional?2D?layer with two rectangular macrocycles,whereas complex 2 features a 3-dimensional?3D?3,4-connected with 2-fold interpenetrating tfa network.Complex 2 is porous and exhibits selective adsorption of CO₂over CH₄,indicating its potential applications in selective gas separation.?2?Amino functionalizaition.UMCM-151 was synthesized based on aromaticity tricarboxylic acid ligand H₃L⁴ with Cu²⁺.Complex 3 synthesized based on a new amino-functionalized tricarboxylic acid ligand H₃L³.Compared with UMCM-151,the amino-functional 3 shows the higher gas adsorption capacity for CO₂.By substituted the coordinated water molecule with pyz molecule,complex 3 turned into 4 as well as complex UMCM-151 turned into 5,which implementation two kinds of the SCSC transformation.Complexes 3,4 and UMCM-151 both show a 3,3,4,4,4-c network with fmj topology,while complex 5 shows a new topology structure?sdf-2?,exihibiting a higher gas adsorption capacity.?3?Using ligands contain methyl and nitrogen carboxylic acid H₂L⁵,H₂L⁶,H₂L⁷ and H₂L⁸,self-assembly with Pb²⁺got complexes 6-10:[Pb?L⁵??DMF?]?6?,[Pb?L⁵??DMF?]?7?,[Pb?L⁶?]?8?,[Pb₃?L⁷?₂?Cl^-?₂]?9?and[Pb₂?L⁸?]·4DMF·H₂O?10?.There are 1D zigzag chain of6,2D wavelike layer of 7,3D Pb-O-C based layer of 8,3D Pb-O-Cl based chain of 9 and 3D non-interpenetrating porous structure of 10.Complex 10 shows the higher gas adsorption capacity for N₂,H₂,CO₂,CH₄,which exhibits selective adsorption of CO₂ over CH₄.