Electronic Structural Approach to Novel Redox Behavior of Uranium to Explore Chemical Aspects of Nuclear Energy Systems

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02663
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 31010:Nuclear engineering-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Takao Koichiro 東京工業大学, 科学技術創成研究院, 准教授 (00431990)
• Co-Investigator(Kenkyū-buntansha): 津島 悟 東京工業大学, 科学技術創成研究院, 特任准教授 (80312990)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 錯体化学 / ウラン / 酸化還元反応 / ノンイノセント配位子 / 電子構造論

Outline of Final Research Achievements

Redox behavior of uranium is one of essential fundamentals in nuclear chemistry. Recently, metal complexes in which ligand itself exhibits redox activity have been reported, implying that describing redox reactions of U complexes solely by a change in the valence of the center metal is no longer appropriate. Therefore, it is important to deepen our detailed understanding by introducing electronic structure theory, which deals with correlation between molecular structure and electronic state of a complex of interest. In this study, we have clarified redox behavior of several U complexes bearing redox-active ligands as well as determining factors of redox active sites in these molecular structures by combining experimental approach (e.g., molecular design of ligands, synthesis and characterization of U complexes, and electrochemical measurements) with theoretical analysis using quantum chemical calculations.

Free Research Field

アクチノイド錯体化学

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた成果は、使用済み核燃料や放射性廃棄物の処理・処分および福島原発事故復旧といった原子力化学における重要な共通基盤であるウランの酸化還元挙動の新たな局面を切り拓くものであり、提案時に目的とした原子力化学における学術基盤強化に大きく貢献するものである。また、学術面だけに留まらず、レドックスアクティブ配位子に誘起されるウラン錯体の新規反応性開拓など更なる機能創出など劣化ウランの有効活用および資源化のための重要な技術基盤の構築にもつながる重要な知見が得られた。