Synthesis Structure And Characterizations Of Uranium(Ⅵ) Complexes

Nowadays, compared to fossil fuels, nuclear energy is the clean and efficient energy, its energy density by millions, and do not emit a huge amount of atmospheric pollutants. The uranium is used to fuel nuclear power, and the uranium resources need to be collected from nature resources. The nuclear fuel in the reactor releases energy and, then produces the spent fuel that contains a large amount of radioactive elements, mainly uranium (U) element. The spent fuel needs to be processed (referred to as the spent fuel processing), therefore the nuclear fuel can be achieved utilization. Moreover uranyl compounds have outstanding photoelectric effect, nonlinear optical properties and excellent fluorescence properties. Thus, in recent years, study of uranyl complexes has been widely attracted and paid strong attention.This thesis mainly focuses on the synthesis of UO22+and common phosphoric acid or hydrofluoric acid, and research on the diversity of uranyl inorganic complexes. Meanwhile, the complexes were tested to characterize and explore their properties. And the authors make further study on the exploration of the diversity and novelty of these crystal structures. Our results are as follows:1. The mixed solution that contains uranyl nitrate, phosphoric acid or hydrofluoric acid, alkali metal ions (nitrate) and organic ligans under hydrothermal conditions synthesizes three novel inorganic uranyl compounds. The structures of these three compounds are characterized by X-ray single crystal diffraction technique, and measured by solid-state fluorescence spectroscopy. The compounds have strong fluorescence properties that uranyl compounds do peculiar nature. Here, the organic ligand is no coordinated in the compound, while the ligand play the role of a temporary template agent.2. Under hydrothermal conditions, uranyl nitrate, phosphoric acid and organic solvents (terephthalic acid) with the introduction of transition metal ion Ni2+, synthesize a unique uranyl compound that is, so far, only transition metal ions as the template agent. The property was carried out by elemental analysis, infrared spectroscopy and Raman spectroscopy. Meanwhile the characterizations that the structure was measured by X-ray single-crystal spectroscopy and thermal gravimetric analysis proved that Ni2+in coordination with this compound plays the role of a template agent, is and this compound has a high degree of crystallinity.