Construction Of Metal Organic Frameworks Based On Nitrogen Heterocyclic/Carboxylic Acid Ligands And Their Applications In Adsorption And Catalysis

Metal-organic frameworks（MOFs）is an organic-inorganic hybrid material,which is built from organic ligands and metal centers assembled by coordination bonds.Due to their porosity and functionality,MOFs show the potential application in many areas,such as gas storage,separation,catalysis,sensing,and luminescence.Currently,however,for MOF chemistry,the development of novel structure,as well as the exploration between structure and performance remain the urgent issues.In this paper,based on the design and combination of building blocks,we obtained 9 novel MOFs by using multiple solvothermal synthesis methods.These MOFs were structurally characterized by single-crystal X-ray diffraction,and their performance measurements and analyses in catalysis,adsorption,or solid-state fluorescence were carried out.（1）Three kinds of novel metal-organic framework materials were prepared using two ligands:4,4’,4’’-tricarboxylic acid triphenylamine（H₃L）and 1,4-bis（pyridin-4-yl）benzene（bpb）.（RH-1～RH-3）.We investigated their catalytic performance for the cycloaddition of carbon dioxide and the selective carbon dioxide adsorption performance of RH-1.RH-1 not only exhibits excellent selective CO₂ adsorptions over CH₄ and N₂,but also show certain catalytic activity in CO₂ cycloaddition with epoxides.（2）Using 3-pyrazinyl-1,2,4-triazole（Hpzta）,trimesic acid（H₃btc）,2-nitro-1,4-phthalic acid（H₂nth）,and 2,5-bis（1H-Imidazol-1-yl）terephthalic acid（H₂dtpa）as the ligand,four metal-organic framework materials with different structures and novel structures were prepared.We explored the catalytic performance and recyclability of 4-nitrophenol for hydrogenation.The experimental results show that RH-4,RH-5 and RH-6 can effectively catalyze the hydrogenation experiments of 4-nitrophenol,and have good cycle stability,which can still maintain high efficiency after 10 cycles of testing active.（3）Using1,3,5-trimethyl-2,4,6-tris（4-pyridyl）benzene（TPB）,2,2-biphenyldicarboxylic acid（H₂bpy）,and 2-（1H-1,2,4-Triazol-1-yl）benzene-1,3,5-tricarboxylic acid（H₃typt）as ligands,two metal-organic framework materials with three-dimensional structure and novel structure were prepared and explored their absorption and separation properties of organic dyes.The experimental results show that RH-8 can efficiently adsorb anionic methyl orange dye,and selectively adsorb methyl orange in the mixed solution of methyl orange and rhodamine B.