Based On The Biphenyls Organic Ligands Polymer Synthesis, Characterization And Nature Study

Metal-organic framworks (MOFs) are a kind of compounds with periodic network structure which are constructed by small molecular ligands and metal ions or clusters through self-assemble process. As an important new kind of porous material, it is more controllable in pore size and shape and the synthesis condiction is mild. These materials have been intently investigated due to their structureal diversities as well as potential applications in areas such as catalysis, separations, storage, photoluminescence, magnetism and nonlinear materials.There are two parts in this thesis: First, we designed and synthesized a novel carboxylate ligand 3,4'-biphenyldicarboxylic acid (3,4'-bpdc). In order to synthesis porous MOF, we chose Cu (Ⅱ) to coordinate with 3,4'-bpdc and got three MOFs: [Cu(OOCC₆H₄C₆H₄COO)(H₂O)·DMF·2H₂O]_n (CC-1), [Cu(OOCC₆H₄ C₆H₄COO)(H₂O)·2DMF·4.5H₂O]_n (CC-2), [Cu(OOCC₆H₄ C₆H₄ COO) (C₅NH₅)₂·(C₃H₇NO)_0.5]_n (CC-3). We got other four MOFs by the reactions with 3,4'-bpdc and transition metal salts, showed as:[Co(OOCC₆H₄C₆H₄COO)(C₅NH₅)₂]_n (CC-4), [Mn(OOCC₆H₄ C₆H₄ COO)(C₅NH₅)₂]_n (CC-5), [Zn(OOCC₆H₄C₆H₄COO)(H₂O)]_n (CC-6), [Cd(OOCC₆H₄C₆H₄COO)(C₃H₆NO)]_n(CC-7). Second, we designed and synthesized a novel phosphonic acid ligand 4'-phosphonobiphenyl-4-carboxylic acid (4,4'-pbpca). We got two MOFs by the reactions with 4,4'-pbpca and Zn(Ⅱ): [(Zn_2.5O₂)(O₃PC₆H₄C₆H₄COO)]_n(CP-1), CP-X. X-ray single-crystal diffraction, elemental analysis (EA), infrared spectroscopy (IR) and thermogravimetric analysis (TGA) were performed. The crystalline phase purity of each sample was independently confirmed by powder X-ray diffraction.CC-1 and CC-2 are supramolecular isomers both constructed from the Cu(Ⅱ) paddle-wheel units [Cu₂(O₂CR)₄] and the biphenyl linkers. Although the binuclear paddle-wheel unit has been reported as a common building block for metal-carboxylate frameworks construction, in those two structures, the two Cu(Ⅱ) paddle-wheels are distinct due to the different coordination modes of the carboxylate groups from different positions. Those two polymorphs CC-1 and CC-2 possess diamond and NbO net topologies, respectively. In spite of the structural interpenetrating, they exhibit 1-D large channels and show the abilities to adsorb H₂. CC-3 can translate to CC-1 as desorption of pyridine. CC-4 and CC-5 are isostructures with the same structure. Co (Ⅱ) (Mn) are coordinated by two pyridine, two O from the 3-position of the carboxyl groups and one O from the 4'-position of the carboxyl groups. The structure of CC-4 and CC-5 are 2-dimension (2-D) layers. In CC-6, Zn (Ⅱ) is coordinated by two O from the 3-position of the carboxyl groups and one O from the 4'-position of the carboxyl groups and one H₂O forming 1-D chain. CC-7 is also 2-D layers constructed by Cd and 3,4'-bpdc.CP-1 is a traditional pillar-layered structure in which the distance between inorganic layers is 12(?). CP-1 is thermally stable to 470℃. We confirmed the existence of CP-X by IR and XRD, and we found CP-1 and CP-X can translate into each other at the different temperature.