Design criteria for tetradentate phenanthroline-derived heterocyclic ligands to separate Am(III) from Eu(III)

Strong Periodic Tendency of Trivalent Lanthanides Coordinated with a Phenanthroline-Based Ligand: Cascade Countercurrent Extraction, Spectroscopy, and Crystallography

Phenanthroline-diamide ligands have been reported in the selective separation of actinides over Eu(III); on the contrary, relevant basic coordination chemistry studies are still limited, and extraction under actual application conditions is rarely involved. In this work, N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline [Et-Tol-DAPhen (L)] was applied to explore the coordination performance of lanthanides in simulative high-level liquid waste. For the first time, cascade countercurrent extraction was conducted with Et-Tol-DAPhen as the extractant, which reveals the periodic tendency of the extraction efficiency of lanthanides to decrease gradually as the atomic number increases. Comparison of elements with similar radii verifies the hypothesis that the increase in the atomic number leads to a decrease in the ionic radius, thus reducing the coordination and extraction capacity of ligands. Slope analysis, electrospray ionization mass spectrometry, and ultraviolet-visible titration results show that the ligand forms 1:1 and 1:2 complexes with lanthanides and the coordination ability follows the tendency of extraction efficiency, and the first crystal structures of Lns(III) with a phenanthroline-diamide ligand, i.e., [LaL(NO₃)₃(H₂O)] and [LaL₂(NO₃)₂][(NO₃)], were obtained, which confirms the conclusions described above. This work promises to enhance our comprehension of the chemical properties of Lns(III) and offer new clues for the design and synthesis of novel separation ligands.

Separation of actinides from lanthanides associated with spent nuclear fuel reprocessing in China: current status and future perspectives

Developing necessary reprocessing techniques to meet the remarkable increase of spent nuclear fuels (SNFs) is crucial for the sustainable development of nuclear energy. This review summarizes recent research progresses related to the SNF reprocessing in China, with an emphasis on actinides separation over lanthanides through three different techniques, hydrometallurgical reprocessing, pyrometallurgical processes, and selective crystallization based separation. Some future perspectives with respect to advanced actinide separation are also given.

Unusual complexation behaviors of R-BTPs with water molecule and Pd(ii) caused by electronic modulation of substituents on BTP backbone: new insights into palladium separation under the framework of minor actinides’ partitioning

A 1 : 1 solid palladium complex with any tridentate bis-triazine ligand has been isolated and structurally characterized for the first time.

Solvent extraction of americium(iii) and europium(iii) with tridentate N,N-dialkyl-1,10-phenanthroline-2-amide-derived ligands: extraction, complexation and theoretical study

Herein, the extraction and complexation of americium(iii) and europium(iii) with three N,N-dialkyl-1,10-phenanthroline-2-amide analogues were investigated, and theoretical calculations were carried out.

Europium, uranyl, and thorium-phenanthroline amide complexes in acetonitrile solution: an ESI-MS and DFT combined investigation

ESI-MS and density functional theory (DFT) methods were combined to elucidate the complexation mechanisms of tetradentate phenanthroline amide ligand with Eu(iii), U(vi), and Th(iv) in an acetonitrile solution.