Highly Selective Synergism for the Extraction of Lanthanoid(III) Ions with β-Diketones and Trioctylphosphine Oxide in an Ionic Liquid

Role of Tf2N− anions in the ionic liquid–water distribution of europium(iii) chelates

“…Acidic chelating reagents such as b-diketones can potentially overcome these problems. [23][24][25][26][27][28][29][30][31] Although it has been found that IL distribution systems for neutral complexes also exhibit high extraction performance compared with conventional organic solvent systems, the cause of the extraction enhancement except the ion-exchange mechanism 23 has yet to be claried. Therefore, in-depth systematic studies on IL distribution systems of metal chelates are required.…”

Synergistic Extraction Equilibrium of Lanthanide(III) Ions with Benzoylacetone and a Neutral Ligand in an Ionic Liquid

“…ionic diameter, coordination number, hydrolysis behavior in solution, and hardness as Lewis acids. We investigated the synergistic extraction of Ln(III) with -diketones and several neutral ligands in a water-IL system [4][5][6]. The synergistic enhancement of the extractability depends largely on the type of the neutral ligand, e.g.…”

“…The synergistic enhancement of the extractability depends largely on the type of the neutral ligand, e.g. selective extraction of lighter Ln(III) was achieved with 18-crown-6 as a synergist [5] while heavier Ln(III) were extracted selectively with trioctyphosphine oxide (TOPO) as a synergist [6]. It was also found that the separation efficiency of Ln(III) varied with the acidity of the diketones using as the extractants, e.g.…”

“…It was also found that the separation efficiency of Ln(III) varied with the acidity of the diketones using as the extractants, e.g. the separation factor between Eu(III) and Lu(III) in the synergistic extraction system using benzoylacetone (Hba) with a higher pK a is significantly larger than those with other -diketones [6]. Although synergistic extraction of Ln(III) in ILs has been investigated by a variety of groups [7][8][9][10], comprehensive understanding of the unique extraction mechanism in ILs has not yet been achieved.…”

Formation of Minimal Third Phase in Ionic Liquid Extraction System with Trioctylphosphine Oxide and Its Possible Application to Extraction Concentration

“…Also in the IL extraction, the possible use of TOPO has been energetically investigated. [7][8][9][10][11][12][13][14] However, Liu et al made mention in their literature 15 that the use of TOPO on the IL extraction resulted in the formation of an "undesirable" third phase.…”