Design And Synthesis Of Amine-linked Frameworks For Energy Storage And Conversion

By linking a series of small organic molecules,clusters into 2D or 3D infinite underlying networks,reticular chemistry has established its unique status in material science.Including Metal-Organic Frameworks(MOFs),Covalent Organic Frameworks(COFs),Zeolite Imidazole Frameworks(ZIFs)etc.,more and more kinds of these crystalline porous inorganic or organic compounds have been successfully synthesized and characterized,enriches this subject to large extent.Specifically,COFs and MOFs have different kind of dynamic chemistry,revisable covalent bonding formation among organic molecules for COFs and revisable coordination bonding formation between organic molecules and metal clusters/metal ions for MOFs(Including ZIFs).The multiple varieties it branches,abundant applications such as gas adsorption recognition and separation,catalysis bio or medical use etc..While small kinds of linkages for COFs have been expended till now,in which dynamic imine chemistry plays a significant row in COF chemistry as its high reversibility imine COFs always have good crystallinity.Thus explore new linkages and combine different kinds of linkages could largely enrich the relationship from structure to function in the chemistry beyond molecules.This dissertation mainly contains two parts:(1)We discovered the appropriate reduce reaction condition through model reaction with N-benzylidene aniline,synthesized 3D imine COF COF-300 and applied the reduction reaction on COF-300 to obtain the amine-linked COF COF-300-AR.The quantitative reduction in solid state was confirmed by Fourier transform infrared and cross-polarization magic angle spinning NMR(both ¹³C and ¹⁵N)spectroscopy.These amine COFs were highly crystalline also they exhibited excellent chemical stability in strong acids and bases.We loaded tetraphenylethylnene into the pores of COF-300-AR,blue fluorescence of TPE was observed across the entire COF crystal showing the good retention of porosity after reduction.The abundant amino groups in the COF-300-AR backbone facilitated the electrochemical reduction of CO₂ on silver electrodes in a concerted manner and led to selective generation of CO in comparison with bare silver electrode.The porosity of COFs favored molecular diffusion to the electrode surface,and the amine functional groups close to the electrode surface promoted CO₂conversion efficiency by forming carbamate intermediates.(2)By using a bifunctional ligand 1-H-pyrazole-4-aldehyde,two kinds of binary linkage frameworks with covalent bond imine and coordination bond Nickel-pyrazole bond were successfully synthesized:Ni-Pz A-hz and Ni-Pz A-TAE.Ni₈O₆Pz₁₂secondary building unite(SBU)together with hydrazine hydrate or tetra(4-aminopthenyl)ethylene were subjected as building block using solvothermal method to give fcu and ftw topology frameworks.Powder X-ray diffraction(PXRD)patterns and Retiveld refinement applied on them showed the good crystallinity of these two frameworks and the conformation of these two structures.High resolution transmittance electron microscopy(TEM)image and electron diffraction also gave some evidences.Nitrogen adsorption isotherms showed the permanent porosity.One of the structures,Ni-Pz A-hz was subjected to water adsorption tests.High amount water uptake up to 0.79 g/g was achieved at 30%humidity,after 69 cycles this material showed less than 5%decay in total water uptake.