Adsorption Properties Of Metal-Organic Frameworks Materials Assembled By Hetero Pyridine And Carboxylate Ligands

Metal-organic frameworks（MOFs）have been widely pursued for their large surface area,diverse architectures and functional pores.By reasonably designing organic ligand and selecting metal source,MOFs materials with desire architecture and chemical functionality can be synthesized.As a new type of functional porous material,MOFs materials indicate potential applications in gas adsorption and separation,chemical sensor,proton conduction and drug deliver,etc.As for these applicaitons,gas adsorption and separation is regarded as the most valuable for the properties could be improved by introducing open metal sites（OMSs）,Lewis basic sites（LBSs）or interpenetration.Hence,MOFs is a type of good materials for the practical application of CO2 capture,gas storage and natural gas purification.Therefore,we have launched a serious of research about the gas adsorption and separation for MOFs materials.In this thesis,by using powerful synthesis strategies of secondary building unit（SBU）and supermolecular building block（SBB）,we have successfully synthesized eleven novel MOFs materials based on two organic ligands（H₂BCPPy = 3,5-bis（4’-carboxyl-phenyl）pyridine,H₄ BDCPPy = 2,6-dis（3’,5’-dicarboxylphenyl）pyridine）and different kinds of metal sources.According to attentive analysis of the structures,we investigated their properties for gas adsorption and separation,iodine adsorption and release,organic dyes adsorption and separation and so forth.The main achievements are mainly focus on the following aspects:（1）By using H₂ BCPPy as organic ligand which possesses pyridine and dicarboxylate groups simultaneously,we have synthesized five novel MOFs materials with different copper salts and named them as compounds 1-5.Copper nitrate is used as the metal source to synthesize compounds 1 and 2.By modulating the kinds of reaction solvents,two novel MOFs materials are synthesized which consist of the same inorganic SBUs of classical Cu-paddlewheel.Copper iodide is used as the metal source to synthesize compounds 3 and 4.By introducing iodine ionic in the synthetic system and modulating the molar ratio of metal source and ligand,two different novel MOFs materials are synthesized which consist of the same inorganic SBUs of classical Cu-paddlewheel and Cu4I4 cluster.Compound 3 possesses the largest sustainable pore volume among the MOFs based on Cu4I4 clusters.Moreover,it exhibits commendable selectivity for O2 over N2,and C3H8 over CH₄.Additionally,compound 4 exhibits impressive performance for I2 sorption and release in solvents.The metal source to synthesize compound 5 is copper sulphate.By introducing sulphate in the synthetic system,compound 5 possesses a rarely reported inorganic SBU of hexa-nuclear [Cu6O2（SO4）6L4] cluster and the classical Cu-paddlewheel.The whole 3D framework possesses a large window size of 25.3 ? with high solvent-accessible volume accounting for approximately 75.8% of the cell volume.On the basis of the anionic framework and large pore volume,compound 5 could efficiently adsorb cationic dyes（MLB,MV,Rh B）and neutral dye（NR）,but exclude anionic dyes（MO and Orange II）.With respect to the proportional mixture dyes with different charges for MO & MLB and Orange II & MLB,compound 5 could be able to selectively adsorb the cationic dye MLB efficiently.（2）By using the same H₂ BCPPy ligand,four novel MOFs materials with high stabilities have been synthesized（compounds 6-9）.Compounds 6 and 7 are analogues and both of them comprise of the same inorganic SBU which possesses 9-connected trinuclear metal cluster.The 9-connected trinuclear [In3O（CO2）6N3] SBU is rare occurrence.Compound 6 shows high stabilities in water vapor and good performance for gas adsorption and separation.By modulating the reaction solvent of compound 7,2D layered compound 8 with infinite metal chain is successfully synthesized,which possesses unique luminescence properties for the metal-to-ligand charge transfer（MLCT）.Compound 9 exhibits outstanding performance for sieving small gases owing to its ultramicropores of 3.5 ?.（3）By using H₄ BCPPy as organic ligand which possesses pyridine and tetracarboxylate groups simultaneously,we have synthesized two novel MOFs materials 10 and 11 via supermolecular building blocks（SBBs）method.Both of them display rare occurrence of linear bi-paddlewheel tetranuclear cluster and possess intriguing metal-organic polyhedron（MOP）cage.Compound 10 shows high BET surface areas and good performance for gas adsorption and separation.Compound 11 displays a rare high 48-connected MOP cage.In summary,by using the powerful strategy of SBUs and SBBs,we have synthesized eleven novel MOFs with two kinds of organic ligands which possess both pyridine and carboxylate groups.In addition,taking advantage of the high porosity of the compounds,their applications for gas adsorption and separation,I2 adsorption and release,organic dyes adsorption and separation were investigated by combining the experimental and theoretical simulation.All of the compounds which are reported in this thesis would enlarge the family of MOFs materials.