Journal Article

Synergistic Solvent Extraction of Lanthanoids with Traditional Ligands (4-Acylpyrazolone and Bidentate Nitrogen Bases) in a Nontraditional Diluent Confirmed by Slope Analysis and NMR

Todorova, Nina, Simova, Svetlana, Atanassova, Maria

2025

Overview

The synergistic solvent extraction of La(III), Eu(III) and Lu(III) with a chelating extractant, 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HL), and neutral bidentate heterocyclic amines, such as 1,10-phenanthroline (S1 (phen)) or 2,2′-bipyridine (S2 (bipy)) in an ionic liquid of the imidazolium family [C1C4im+][Tf2N−] was investigated. Synergistic effects have been observed to result from the formation of a ternary complex in the organic phase, particularly in cases where the ligand S is a neutral synergistic agent. Examples include La(L)2(S2)2, Eu(L)3(S2) and Lu(L)x(S2)2, as well as La(L)3(S1)2, Eu(L)2(S1) and Lu(L)3(S1)x). The parameters of the solvent extraction process were determined and the influence of the synergistic agent on the extraction process was discussed. Additionally, the synergistic increase and separation factors were determined. The equilibrated organic phases were analyzed using 1H NMR spectroscopy to elucidate the synergism in an extraction mechanism. The role of the ionic diluent in complexation processes and selectivity was investigated with the employment of the two synergistic agents for various metal s-, p-, d- and f-cations in the periodic table, with almost 22 metal ions.

• Publisher: MDPI AG,MDPI
• Subject: 1,10-phenanthroline / 2,2′-bipyridine / 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one / Amines / Chelating agents / Chemistry / lanthanoids / Ligands / Metals / Nitrogen / NMR / Nuclear magnetic resonance spectroscopy / Periodic system / Solvent extraction processes / synergistic extraction