Theoretical insights into the separation of Am(III) over Eu(III) with PhenBHPPA.
Due to the similar chemical properties of actinides An(iii) and lanthanides Ln(iii), their separation in spent nuclear fuel reprocessing is extremely challenging. A 1,10-phenanthroline dipicolinamide-based ligand (PhenBHPPA) has been identified to possess a selectivity for Am(iii) over Eu(iii) and could potentially be used for group actinide extraction. In this study, quasi-relativistic density functional theoretical calculations have been used to disclose the interaction mechanisms of Am(iii) and Eu(iii) complexes with PhenBHPPA. The electronic structures, bonding nature, QTAIM (Quantum Theory of Atoms in Molecules) analyses and thermodynamic behaviors of the Am(iii) and Eu(iii) complexes with PhenBHPPA have been explored in detail. According to the Wiberg bond indices (WBIs) and QTAIM analyses, interactions between the ligand and metal cations (Am(iii) and Eu(iii)) exhibit a weakly covalent character. Thermodynamic analyses show that the charged complexes [ML(NO3)2](+) appear to be the most stable species in the complexation processes. Moreover, it is more energetically favorable for PhenBHPPA to bind to Am(iii) compared to Eu(iii). Our study could render new insights into understanding the selectivity of the ligand towards minor actinides and the separation of An(iii) from Ln(iii) via liquid-liquid extraction.
Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. shiwq@ihep.ac.cn.
Han
H
Wu
Qun-Yan
QY
Wu
Cong-Zhi
CZ
Wang
Jian-Hui
JH
Lan
Zhi-Rong
ZR
Liu
Zhi-Fang
ZF
Chai
Wei-Qun
WQ
Shi
D008671:Actinoid Series Elements / Q000302:isolation & purification; D000576:Americium / Q000737:chemistry*; D000577:Amides / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000302:isolation & purification; D059625:Liquid-Liquid Extraction; D008958:Models, Molecular; D015394:Molecular Structure; D010618:Phenanthrolines / Q000737:chemistry*; D010848:Picolinic Acids / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics
D008671:Actinoid Series Elements; D000577:Amides; D056831:Coordination Complexes; D028581:Lanthanoid Series Elements; D010618:Phenanthrolines; D010848:Picolinic Acids; D005063:Europium; C003142:picolinamide; D000576:Americium; C025205:1,10-phenanthroline