Synthesis And Structure Analysis Of Uranyl Compounds

Uranium, as the most representative actinide element, has received considerable attention because of its diverse chemical compositions and various architectures as well as its physicochemical properties involved in the nuclear fuel cycle. The coordination chemistry of uranium is dominated by U(VI), in the form of uranyl cation UO22+, which features two axial oxygen atoms and favors4-6additional coordination sites in the equatorial plane, yielding tetragonal, pentagonal, and hexagonal bipyramidal geometries. The UO22+species with inactive U=O double bonds generally is coordinated through the equatorial ligands, yielding infinite chains or sheets, while three-dimensional (3-D) framework structures are formed occasionally. As3-D frameworks usually exhibit many outstanding properties such as porous adsorption, photoelectronic effects, nonlinear optical properties, and superior thermal stability to low-dimensional structures, the construction of3-D uranyl frameworks is highly desirable. Popular strategy to isolate3-D uranyl compounds is heteroatom incorporation by introducing extra metal ions to the reaction systems and designing three-dimensional coordination ability of the ligands.This thesis is committed to the synthesis and properties of functional uranyl compounds. The compounds have been prepared under hydrothermal conditions, which yield fourteen uranyl organic coordination polymers. Six three-dimensional structure of the compounds have been successfully prepared due to the theory of three-dimensional uranyl compounds, and the influence of the spatial configuration of ligands and the hetero atom on the compound structure have been studied, the fluorescence properties of the compounds have been explored in this paper. Uranyl ion favors the variety configuration in our study, reflecting its rich coordination characteristics.