Study On Syntheses, Characterizations And Properties Of Complexes Based On Biphenyltetracarboxylic Acid

Metal-organic frameworks (MOFs) are an interesting class of hybrid materials that are built from metal ion connectors and bridging ligands, allied with potential applications in gas storage, selective absorption, chiral separation, controlled drug release, catalysis and so on. The functionality of these materials can be achievable by judicious selections of inorganic species or organic linkers. Therefore, the rational design to prepare hybrid MOFs with special structures and properties has raised a wide interest among the researchers. In this thesis, we constructed several complexes of three different systems, basing on3,3’,4,4’-biphenyltetracarboxylic acid, one of the arylpolycarboxylate organic ligands. All of them have been characterized by IR, thermal gravimetric analysis, single X-ray crystallography and elemental analyses. We also investigated their properties on themal behaviors, solid state luminescence, chirality and catalysis.1. Three new isostructural3D lanthanide MOFs (Ln(HBPTC)(H2O))(Ln=Tb(1), Pr(2), Nd(3); H4BPTC=3,3’,4,4’-biphenyltetracarboxylic acid) have been synthesized under hydrothermal conditions using imidazole as a structure-directing agent. Compounds1-3exhibit high thermal stability, at least being stable up to410℃. Furthermore, the luminescence studie swere performed on compound1and its dehydrated phase in the solid state at room temperature. The results demonstrate that compound1displays intense green emission, implying its potential application as fluorescence material. And the luminescence of1is quenched when removing the coordinated water molecules.2. Under similar solventhermal conditions, two2D MOFs [Zn2(BPTC)(2DMSO)(2Py)](4) and [Zn2(BPTC)(2DMSO)(2DMF)](5) have been synthesized through achiral precursors. Controlling the reaction temperature, coordinated complexes4and5were produced under different solvothermal conditions. It is demonstrated from vibrational circular dichroism that compound4is chiral, while compound5is not.3. A novel MOFs Cd2(BPTC)(DMF)2(6) has been synthesized under solvothermal conditions. The photocatalytic studies on compound6indicate that it is an active catalyst for the degradation of methyleneblue. The catalytic activity of compound6was investigated in different pH values, and the result indicates that compound6shows certain activity at neutral pH value.