Construction And Properties Of Uranyl-organic Coordination Polymers

This thesis mainly researched on centering around the uranyl ions to synthesis functional uranyl coordination polymers, aiming to further discover and study on the diversity of uranyl coordination polymer and structure, and then their properties and applications were explored.This thesis devotes to study the key effect of construction, and properties of uranyl-organic coordination polymers. Hydrothermal reactions of uranyl nitrate and 4,4′-oxidiphthalic acid(H4L) or(2,5-dimethyl-1,4-phenylene)diphosphonic acid(H4DMPDP) resulted in the formation of five new uranyl-organic framework materials, namely(NH4)2[(UO2)3(L)2]·5H2O(ODPA-U1),(NEt4)[(UO2)3(H2O)(L)(HL)](ODPA-U2),(UO2)7(H2O)2(phen)4(L)2(HL)2(ODPA-U3), [(UO2)3(H2O)2(H2DPTP)2]·2H2O(DPTP-U1), and(H2bbi)[(UO2)4(H2O)2(HDPTP)2](DPTP-U2). The preparation, single-crystal structural analysis, X-ray powder diffraction, infrared analysis and photoluminescent properties of these uranyl-organic materials were elucidated.In ODPA-U1, UO7 polyhedra are linked by hexadentate ligands to form a 3D framework with 1D channels, in which are located NH4+ ions and water molecules. While in ODPA-U2 the organic ligands adopt pentadentate and hexadentate coordination models, ligating UO7 pentagonal bipyramids to create a layered structure with channels filled by NEt4+ ions. For ODPA-U3, uranyl square bipyramids are also accommodated together with pentagonal bipyramids, which are linked by tetradentate carboxylate ligands to produce the layered assemble. Phen molecules also coordinate to the uranyl centers to build up the structure. The carboxyphosphonate ligand has been formed through the in situ oxidation of(2,5-dimethyl-1,4-phenylene)diphosphonic acid mediated by UO22+. Single crystal X-ray diffraction analyses reveal that DPTP-U1 possesses uranyl carboxyphosphonate layers that are separated by protonated dipy cations. Whereas DPTP-U2 is in a 3D framework structure with channels filled by protonated bbi cations.