Study on recignition and separation of f-block elements by multidentate N,O-hybrid donor ligands

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K18351
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear engineering
• Research Institution: Tokyo Institute of Technology (2017); Japan Atomic Energy Agency (2016)
• Principal Investigator: Nakase Masahiko 東京工業大学, 科学技術創成研究院, 研究員 (70744332)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 溶媒抽出 / 有機合成 / 単結晶X線構造解析 / 放射光EXAFS / f元素 / アクチノイド / ランタノイド

Outline of Final Research Achievements

In the treatment of high-level radioactive waste, the separation of trivalent lanthanides (Ln(III)) from trivalent actinides (An(III)) is effective to minimize the burden for vitrification and deep geological disposal. In this study, crystallography, extended X-ray absorption fine structure and UV titration were performed to elucidate the relationship between complex structure and coordination strength to develop appropriate ligands for specific f-block elements. In case of symmetrical 2,2'-bipyridyl(Bpy) and 1,10-phenanthroline(Phen), the decreasing ionic radius from light to heavy Ln led to decreases in the Ln-N(Bpy) and Ln-N(Phen) distances, while logb simply increased. However, unsymmetrical N-methyl-N-tolyl-1,10-phenanthroline-2-carboxamide(MeTol-PTA) showed a local maximum in logb and the crystal structures indicated that the bulky phenanthroline moiety of MeTol-PTA may not allow N(MeTol-PTA) to come close to Ln which resulted in suitable arrangement of N and O for specific Ln.

Free Research Field

原子力化学