ELECTROCHEMICAL BEHAVIOR OF URANIUM IN ANHYDROUS FLUORIDE SOLUTIONS

在氟化铯饱和的无水氟化氢和无水HF-CsF中研究铀的光谱和电化学的简便方法。该溶剂的阳极电位极限（在Pt电极上对Cu/CuF_2为2.4 V，对SCE为2.2 V）超过了水的阳极电位极限，并为UF_4提供了高溶解度。溶解度研究包括选定的镧系和锕系盐和氧化物。人们发现它是研究铀的各种氧化态的有用溶剂。铀在无水HF-CsF介质中表现出不同于水溶液中的光谱和电化学行为。U （IV）在未完全饱和CsF的无水氟化氢中氧化为U (V)，只需加热混合物即可完成。分别在Pt、Ni和Cu/CuF_2参比电极上记录了U (V) /U （IV）对的循环伏安图。用控制电位电解法研究了U (VI) /U (V)和U (VI) /U （IV）对。铀(V)以UF_6^-的形式存在于无水HF-CsF中。这与水溶液中已知的U (V)以UO_2^+离子的形式存在的情况相反。

Convenient methods have been developed for spectroscopic and electrochemical studies of uranium in anhydrous hydrogen fluoride saturated with cesium fluoride, anhydrous HF-CsF.This solvent exhibits and extended anodic potential limit (2.4 V vs. Cu/CuF_2 or 2.2 V vs. SCE at a Pt electrode) over that for water, and provides high solubility for UF_4. Solubility studies included selected lanthanide and actinide salts and oxides. It was found to be a useful solvent for studies on the various oxidation states of uranium. Uranium displayd spectroscopic and electrochemical behavior in anhydrous HF-CsF medium which was quite different from that in aqueous solutions. The oxidation of U (IV) to U (V) in anhydrous hydrogen fluoride which was not completely saturated with CsF was accomplished by simply heating the mixture. Cyclic voltammograms of the U (V) /U (IV) couple were recorded at Pt and Ni vs. Cu/CuF_2 reference electrode. The U (VI) /U (V) and U (VI) /U (IV) couples were also investigated by means of controlled-potential electrolysis. Uranium (V) apprently exists as UF_6^- in anhydrous HF-CsF.This is in contrast to aqueous solution where the U (V) species is konwn to exist as the UO_2^+ ion.