Hydroxyl-group functionalized phenanthroline diimides as efficient masking agents for Am(III)/Eu(III) separation under harsh conditions

Yaoyang Liu; Yu Kang; Mingjie Bao; Hong Cao; Chaoqun Weng; Xue Dong; Huaixin Hao; Xiaoyan Tang; Jing Chen; Li Wang; Chao Xu

doi:10.1016/j.jhazmat.2023.132756

Hydroxyl-group functionalized phenanthroline diimides as efficient masking agents for Am(III)/Eu(III) separation under harsh conditions

J Hazard Mater. 2024 Jan 15:462:132756. doi: 10.1016/j.jhazmat.2023.132756. Epub 2023 Oct 11.

Authors

Yaoyang Liu¹, Yu Kang², Mingjie Bao², Hong Cao¹, Chaoqun Weng³, Xue Dong¹, Huaixin Hao¹, Xiaoyan Tang³, Jing Chen⁴, Li Wang⁵, Chao Xu⁶

Affiliations

¹ Institute of Nuclear and New Energy Technology, Tsinghua University, Haidian District, Beijing 100084, China.
² Department of Chemistry, Capital Normal University, Haidian District, Beijing 100048, China.
³ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China.
⁴ Institute of Nuclear and New Energy Technology, Tsinghua University, Haidian District, Beijing 100084, China. Electronic address: jingxia@tsinghua.edu.cn.
⁵ Department of Chemistry, Capital Normal University, Haidian District, Beijing 100048, China. Electronic address: liwang@cnu.edu.cn.
⁶ Institute of Nuclear and New Energy Technology, Tsinghua University, Haidian District, Beijing 100084, China. Electronic address: xuchao@tsinghua.edu.cn.

PMID: 37866146
DOI: 10.1016/j.jhazmat.2023.132756

Abstract

The separation of Lns(III) from radioactive Ans(III) in high-level liquid waste remains a formidable hydrometallurgical challenge. Water-soluble ligands are believed to be new frontiers in the search of efficient Lns/Ans separation ligands to close the nuclear fuel cycles and dealing with current existing nuclear waste. Currently, the development of hydrophilic ligands far lags behind their lipophilic counterparts due to their complicated synthetic procedures, inferior extraction performances, and acid tolerances. In this paper, we have showed a series of hydroxyl-group functionalized phenanthroline diimides were efficient masking agents for Am(III)/Eu(III) separation under high acidity (˃ 1 M HNO₃). Record high SF_{Eu(III)/Am(III)} of 162 and 264 were observed for Phen-2DIC2OH and Phen-2DIC4OH in 1.25 M HNO₃ which represents the best Eu(III)/Am(III) separation performance at this acidity. UV-vis absorption, NMR and TRLFS titrations were conducted to elucidate the predominant of 1:1 ligand/metal species under extraction conditions. X-ray data of both the ligand and Eu(III) complex together with DFT calculations revealed the superior extraction performances and selectivities. The current reported hydrophilic ligands were easy to prepare and readily to scale-up, acid tolerant and highly efficient, together with their CHON-compatible nature make them promising candidates in the development of advanced separation processes.

Keywords: Actinides/lanthanides separations; High acidity; Liquid-liquid extraction; Nuclear waste management.