REDUCTION OF ORGANOMETALLIC URANIUM (IV) BY MEANS OF CONTROLLED-POTENTIAL ELECTROLYSIS.

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07680523
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: エネルギー学一般・原子力学
• Research Institution: TOHOKU UNIVERSITY
• Principal Investigator: HARA Mitsuo TOHOKU UNIVERSITY INSTITUTION FOR MATERIALS RESEARCH, 金属材料研究所, 助手 (90005918)
• Project Period (FY): 1995 – 1996
• Keywords: Tetracyclopentadienyluranium (IV) / Cyclic valtammetry / Controlled-potential electrolysis / Uranium metal

Research Abstract

A compact, stainless steel glove box has bee prepared. The main and side chambers can be independently evacuated and then filled with inert gas. The main chamber has inlet and outlet for circulating cooling water. As the differential pressure in the main chamber is often changed with the use of organic materials and for loading something not be resisted in vacuum, the inert gas can be contaneously passed through two chambers. The apparatus for handling cyclopentadienyl compounds and electrochemical studies were prepared to be assembled in the main chamber.
The dimer dicyclopentadiene was depolymerized, and the resulting cyclopentadiene was distillled and stocked in a freezing box to prevent the repolymerization prior to use. In a three-necked flask, equipped with a reflux condensor and a capillary for argon gas bubbling, diethylether and pieces of potassium metal were placed, and cyclopentadiene in a limitted amounts was added. After the solvent was evaporated, the potassium complex was stocked under vacuum.
Uranium peroxide, precipitated from uranyl nitrate solution by the addition of hydrogen peroxide, was filtered and washed and it was converted into amorphous uranium (VI) oxide by heating in air at 400ﾟC.Uranium (IV) chloride, prepared by a reaction of amorphous uranium (VI) oxide with hexachloropropene, was filtered and washed, and it was used for the preparation of tetracyclopentadienyluranium (IV) by a reaction with cyclopentadienyl-potassium in tetrahydrofuran. The excess potassium complex was removed by extraction with n-pentane. The yield of uranium (IV) complex was very low, and an attemped improvement of the yield was still unsuccessful.
Another study on the redox reactions of uranium in organic solvents containing tetracyclopentadienyluranium (IV) was carried out by means of cyclic voltammetry. Platinum wires were used as working and counter electrodes, and silver wire was used as a reference electrode. Cyclic voltammogram recorded for uranium (III) /uranium (IV) couple showed the reversibility of the redox couple, and some information conerning uranium (IV) /uranium (V) redox couple was obtained.