Coordination Frameworks Based On Biphenyl-3,3’,5,5’-tetracarboxylic Acid: Synthesis, Crystal Structures And Properties

Metal-Organic Framework as a new class of porous crystalline material is built from inorganic metal ions and organic linkers with periodic network structure. It is mainly assembled with coordination bonds, by the aid of hydrogen bond or molecular interactions, and forms varied structures with unique properties. Metal-Organic Frameworks often have many promising applications in gas adsorption and storage, separation, catalysis. In addition, the incorporation of lanthanide metals can give some fluorescent characteristics which can be used in sensors, molecular probe and other fields. Therefore, it is particularly important to design the MOFs and explore the rule of synthesis between the solvent, temperature and p H value and so on.In this thesis, we use aromatic carboxylic acid ligand, 3,3’,5,5’-biphenyl tetracarboxylic acid(H4bptc) as a ligands, prepared eleven porous metal-organic complexes with transition metals through hydrothermal, solvothermal, ionothermal methods. Also, we determined their crystal structures, carried out a preliminary studies on gas absorption, fluorescence. The research content are as follows:1. We chose 3,3’,5,5’-biphenyl tetracarboxylic acid with transition metal salts and rare earth oxide assembled four porous metal-organic complexes [Zn2(BPTC)]n(1), Er(BPTC)(H2O)n(2), [Tb(BPTC)(HCOO)]n(3), [Ho(BPTC)(HCOO)]n(4). Their porous structures were determined by the structure analysis, and we tested the gas adsorption properties of compounds 1 to characterize single crystal X-ray diffraction, and the result indicates that compound 1 has degree of N2 adsorption.2. The introduction of lanthanide metal oxide Tb4O7, Ho2O3, Gd2O3 with 3,3’,5,5’-biphenyl tetracarboxylic acid assembled three kinds of metal-organic complexes [Tb1.5(BPTC)1.5·2H2O·2CH3CH2OH]n(5), [Ho(BPTC)·5H2O]n(6), {[Gd3(BPTC)2(HCOO)2(H2O)2]NH2(CH3)2}n(7). In this experiment, we used multiple solvents including [EMIM]Br ionic liquids and synthesized three complexes containing object solvents in their structures. Tested their fluorescence properties and found that complex 5 has strong fluorescence.3. We use Mn Cl2·4H2O to reaction with 3,3’,5,5’-biphenyl tetracarboxylic acid in different solvent(DMF, DMA, H2O) and got four different manganese complexes {[Mn2(BPTC)(DMF)2(H2O)]DMF}n(8), {[Mn2(BPTC)(DMA)(H2O)2](DMA)}n(9), [Mn2(BPTC)(H2O)2]n(10), {Mn(BPTC)([EMIM]Br)2·2[EMIM]}n(11). We compared the differences of their structures and thermal stabilities. We discussed the effect of solvents on the structures.