Synergistic Effect of 18-Crown-6 Derivatives on Chelate Extraction of Lanthanoids(III) into an Ionic Liquid with 2-Thenoyltrifluoroacetone

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

“…14,15 Recently, the present authors have reported on the synergistic ionic-liquid extraction of lanthanoids(III) (Ln(III)) with 2-thenoyltrifluoroacetone (Htta) as an acidic chelating extractant and several neutral ligands in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][Tf2N]). [16][17][18] In the Htta-18-crown-6 derivative (CE) systems, 17 a synergistic enhancement of the extractability was found for only light Ln(III) from La to Eu, leading to selective extraction of the lighter Ln, while in the Htta-trioctylphosphine oxide (TOPO) system, 18 the synergistic effect increased with an increase in the atomic number, leading to an improvement in the selectivity among Ln(III) ions. The synergism mentioned above has been ascribed to the ion-exchange extraction of specific cationic ternary complexes such as Ln(tta)2(CE) + and Ln(tta)(CE) 2+ 17 or Ln(tta)2(TOPO)3 + and Ln(tta)(TOPO)3 2+ 18 into the IL.…”

A Fluorous Biphasic Solvent Extraction System for Lanthanides with a Fluorophilic β-Diketone Type Extractant

“…1 H-NMR, 19 F-NMR and 13 C-NMR spectra were recorded at room temperature on a JEOL ECA-500 spectrometer at 500 and 125 MHz, respectively. Chemical shifts of 1 H-NMR are relative to an internal standard of tetramethylsilane (δ = 0.0 ppm), and coupling constants are given in Hz.…”

“…Electronic Supplementary Information (ESI) available: 1 H-NMR spectra, 13 C-NMR spectra, 19 F-NMR spectra. This material is available free of charge on the Web at http://www.jsac.or.jp/ analsci/.…”

“…15 For example, in the extraction of lanthanides with Htta, the dependence of the extraction constant values on the extraction solvents has been confirmed. 7,8,[16][17][18][19] Since the toxic and flammable characteristics of many organic solvents are detrimental to the environment, substitutes have been investigated. As an example, ionic liquids (ILs) have gained attention as candidates for the substitution of organic solvents.…”

A Specific Synergistic Effect in Ionic Liquid Chelate Extraction Based on Neutral Ternary Chloro-complex Formation

“…[1][2][3][4] Unlike molecular organic solvents, ILs have a much high polarity and ability as liquid ion-exchangers. Several coordinatively-unsaturated neutral complexes are extracted into ILs due to the former nature, [5][6][7] and several cationic 8,9 and anionic 5,10,11 complexes are also extracted due to the latter nature. Namely, the use of ILs as extraction solvents can result in a novel extraction separation performance.…”