Synthesis And Characterization Of Metal Organic Skeleton Compounds Based On Cage Structure Units

As a new type of functional material, metal organic frameworks, also called coordination polymers metal-organic frameworks(MOFs) have been developing very rapidly due to novel structures and potential applications in chemical research. The thesis consists of five chapters. In chapter1, the introduction part, the definition, structure, and properties of MOFs are introduced followed by the development of the MOFs based on1,3-dicarboxy phenyl fragment containing carboxylate ligands. The research purpose of this thesis is to synthesize MOFs with cage structures as secondary building units using flexible,1,3-dicarboxy phenyl fragment containing octadentate carboxylate ligands. The research goals are to synthesize, characterize and study the properties of these complexes, trying to discover the effect of synthetic conditions on the final structures and the relationships between structures and properties. Chapter2is the core of the thesis. We applied a novel flexible octadentate, carboxylate ligand based on the1,3-dicarboxy phenyl fragment was synthesized, and synthesized a novel two-fold interpenetrated, three-dimentional MOF material built on cages was synthesized and characterized with (X-ray single crystal structure analysis, elemental analysis, X-ray powder diffraction and infrared spectroscopies). It can be stable in air for seven days, but unstable in water. This metal-organic polymer exhibits photoluminescence at room temperature, and the main emission band is at about454nm (λex=340nm). It is also a wide band gap semiconductor with a band gap of3.63eV. In Chapter3, inspired by literature, oxalic acid was added in the synthesis in order to make a non-penetrated MOF of1. Instead, a known oxalate MOF,[(H2NMe2)2Cd3(C2O4)4] which was reported for nonlinear optical (NLO) property. As it was reported for having a porosity of34.7%, we studied its hydrogen storage property and found none. We found this MOF is also a wide band gap semiconductor with a band gap of3.73eV. In Chapter4, MOFs with exceptional high hydrogen storage capability were reviewed. They all have cage SBUs. Other features were also summarized. The synthesis of another flexible octadentate, carboxylate ligand based on the1,3-dicarboxy phenyl fragment was improved. In Chapter5, the work of this thesis was summarized and future work was proposed.