Adsorption Properties Of Metal-organic Frameworks Assembled By Lewis Basic Sites And Tetradental Carboxylate Ligands

Metal-organic frameworks（MOFs）,as one type of porous crystalline materials,have attracted extensive research interests for their diverse applications.Metal-organic polyhedral（MOP）which owns large voids cage and open-channel-type is a prominent building unit to construct MOFs with large pore volume,high surface area and excellent gas uptake capacity.For the sake of constructing polyhedron-based metal organic frameworks（PMOFs）,supermolecular building blocks（SBBs）approach is consider to be an effective strategy which has been used to configure a series of classic PMOFs.In addition,it also indicates that the ligands with functional groups such as amino,imino,amide,urea,imidazole and triazole in the PMOFs may significantly increase the storage and separation performance for CO₂ and other small gases.In this thesis,by using powerful synthesis strategies of SBBs,we have successfully synthesized fifteen novel MOFs materials based on three organic ligands H₄TADIPA,H₄UADIPA and H₄PorTc and different kinds of metal sources.According to attentive analysis of the structures,we investigated their properties for gas adsorption and separation.The main achievements are mainly focus on the following aspects:First,by using H₄TADIPA and H₄UADIPA as orgnic ligands,which possess triazole group and urea group,we have synthesized five novel MOFs materials with the MOP-1 cage and named them as compounds 1-5.Compared with compound 1,by judiciously avoiding the DABCO axial ligand,compound 2 possesses more OMSs and exhibits significant enhancement of CO₂ uptake capacity 210 versus 162 cm³ g^-1at 273 K under 1 bar.Compound 3 has three different sizes of cages,and with the high BET surface areas.By means of modulating the axial ligand and adopting SBBs strategy,which possess high density of LBSs and OMSs,compound 4 and compound5 have been successfully synthesized.Benefiting from the size of axial ligand in compound 5 is smaller than that in compound 4,compound 5 shows larger pore volume and higher BET surface area.It is worthwhile mentioning that both of the two compounds exhibit outstanding adsorption capability for CO₂ ascribed to the introducing of urea groups.Secondly,by using the H₄TADIPA and H₄UADIPA ligands and the same Zinc salt,five novel MOFs materials with high stabilities have been synthesized,which named compounds 6-9.By the benefit from its high density of OMSs and LBSs,compound 6shows good adsorption ability for some small gases and IAST calculation indicates that compound 6 should be a kind of promising material for light gas separation.Compared with compound 7,compound 8 were have good adsorption ability for some small gases.Compound 9 is a three-dimensional framework structure constructed by mononuclear zinc SBUs and the H₄TADIPA organic ligands.Finally,PMOFs material compound 10 has three different sizes and types cages.Compound 10 could efficiently adsorb anionic and neutral dyes,but exclude cationic dyes.By using the post synthetic strategy compound 11 is successfully converted to compound 11’.Compound 11’has higher thermal stability and better capability of gases adsorption and separation than Compound 10.Both compound 12 and compound 13 are 3-D framework,which constructed from mononuclear indium secondary building units and H₄TADIPA organic ligand.However,their have different types and sizes channel.Compound 14 is a double intercalation structure and has good small molecule adsorption properties.Compound 15 possesses a large pore size of channel.In summary,through the single crystal analysis,we carefully analyzed the main structure of each compound.The applications for gas adsorption and separation were examined by combining the experimental and theoretical simulation under the different conditions.