Synthesis And Properties Investigation Of Hydrogen Bonded Organic Frameworks

As an emerging class of highly ordered crystalline porous materials,hydrogen-bonded organic frameworks?HOFs?with high surface area,tunable pores,and low density have become a new research hotspot in chemistry and material science.Similar to the traditional zeolites and carbon-based porous materials,HOFs exhibit excellent potentials in gas adsorption and separation,molecular device,fluorescent probes,proton conduction,and transfer of drug molecules.Therefore,design and synthesis of functional HOFs is particularly important.In this thesis,based on the special suitability of hydrogen bond donor and receptor,we have successfully synthesized five hydrogen-bonded organic frameworks by carefully selecting reaction conditions.The structures and stabilities of the HOFs were characterized by X-ray single crystal diffraction,elemental analysis?EA?,thermogravimetric analysis?GA?,infrared spectra?IR?and X-ray powder diffraction?PXRD?.Meanwhile,the gas adsorption tests and proton conduction properties for some HOFs were also conducted.The main contents include the following points:?1?Two hydrogen-bonded organic frameworks,[?SDX??1,5-NSA?_2.5]·4H₂O?HOF-1?and[?SDX??H₂SO₄?₄]·4H₂O?HOF-2?,were preparedby theassemblyof2,3,6,7,14,15-hexaamoniumtriptycene hexachloride?SDX?with 1,5-naphthalenedisulfonic acid?1,5-NSA?and sulfuric acid,respectively.X-ray single crystal diffraction shows that HOF-1 and HOF-2 both bear three-dimensional?3D?framework structures,which are connected by multi-mode hydrogen bonds.GA and variable temperature XRD tests display that the frameworks of HOF-1 and HOF-2 can keep stable till 220^oC and 130^oC,respectively.Meanwhile,HOF-2 has hexagonal pores.BET tests show that it can adsorb H₂,N₂ and CO₂.?2?Two hydrogen-bonded organic frameworks,[?C₃H₈N₆?²⁺?SO₄?^2-]?HOF-3?and[?C₃H₇N₆?₂²⁺(C₁₀H₁₀O₈)^2-]·2H₂O?HOF-4?,were also prepared by the assembly of Melamine?C₃H₆N₆?with sulfuric acid and 1,2,4,5-Cyclohexanetetracarboxylic acid(C₆H₁₄O₈),respectively.X-ray single crystal diffraction shows that HOF-3 and HOF-4 also bear three-dimensional framework structures,which are also connected by multi-mode hydrogen bonds.Meanwhile,HOF-4 possesses one-dimensional pores along a axis and c axis.GA and variable temperature XRD tests display that the frameworks of HOF-3 and HOF-4 can keep stable till 150^oC and 200^oC,respectively.?3?In order to explore the formation modes of hydrogen bond between amido and sulfate,HOF-5 was synthesized by the self-assembly of 2,4,5,6-tetraaminopyrimidine sulfate.X-ray single-crystal diffraction analysis show that HOF-5 also bear three-dimensional framework structure.GA and variable temperature XRD tests display that the frameworks of HOF-5 can keep stable till 100^oC,and then produce phase change.Meanwhile,impedance tests exhibit that it has good proton conduction property.