Designing Metal-Organic Frameworks with Hierarchical Structure.

摘要

Metal-organic frameworks (MOFs) are hybrid crystalline materials composed of metal ions and organic bridging ligands. MOFs have a variety of potential applications, including gas storage, separation, catalysis, and drug delivery. This work focuses on designing new MOFs with hierarchical pore structures.;In particular, a new magnesium MOF was constructed from a tetracarboxylate ligand and in-situ formed magnesium carboxylate clusters. The structure of the magnesium MOF was fully characterized by single-crystal X-ray crystallography, powder X-ray diffraction, thermal gravimetric analysis, and gas adsorption analysis. The MOF was found to be significantly porous to both N2 and CO2. The design of hierarchical MOFs based on tetra nuclear sulfonylcalixarene complexes was also attempted. A tetranuclear precursor based on cobalt (II) acetate and p-tert-butylsulfonyl calix[4]arene was synthesized following a modified literature procedure.;Compared to the crystal structure described in the literature, the Co-precursor synthesized in this thesis work has a subtly different crystal packing. The Co-precursor was characterized by single-crystal X-ray crystallography, powder X-ray diffraction, and thermal gravimetric analysis and its utility as a building block to construct hierarchical MOFs was examined.