Synergistic Effect in the Solvent Extraction and Separation of Lanthanoids by 4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one in the Presence of Monofunctional Neutral Organophosphorus Extractants

Abstract

4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one (HL) has been synthesized and its complexation properties in solution were examined. Mixed ligand chelate extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) from chloride medium at constant ionic strength μ = 0.1 into C 6 H 6 with HL in combination with one of the three phosphine oxide compounds trioctylphosphine oxide (TOPO), tributylphosphine oxide (TBPO), or triphenylphosphine oxide (TPPO) as well as with tributylphosphate (TBP) was studied. The interaction between the extractants in C 6 H 6 -d 6 has been studied by 1 H, 13 C, and 31 P NMR spectroscopy and its influence on the synergistic extraction of Nd(III) ion has been investigated. The composition of the extracted species was established as LnL 3 3 HL with HL alone and as LnL 3 3 2S in the presence of TOPO, TPPO, and TBP or LnL 3 3 S with the mixture of HLÀTBPO. A synergic effect up to 10 6 was observed for the extraction of the above-mentioned lanthanoid ions with binary mixtures of extractants. The change of the synergistic agent causes a significant increase of the K L,S values. The parameters of the extraction process were determined and the separation factors were calculated.

Comparing extraction, synergism and separation of lanthanoids using acidic and neutral compounds in chloroform and one ionic liquid: is the latter always “better”?

“…An important problem for systems containing mixtures of extractants used for solvent extraction of metals is their possible interaction. 1,7 The unfavorable role of the extractant interaction was noted by Zhang. 42 45 years ago Marcus and Kertes 43 have also pointed out that the interaction between an acidic and a neutral extractant is a reason for the destruction of the synergism.…”

“…The samples were shaken mechanically (Orbital Shaker OS-20, Boeco, Germany, 120 rpm) for 45 minutes at room temperature (22 AE 2 C) which was sufficient to reach equilibrium. [1][2][3][4][5][6][7][8] Aer the separation of the phases, the metal concentration in the aqueous phase was determined spectophotochemically (S-20 Spectrophotometer Boeco, Germany) using Arsenazo III. 38 The concentration of the metal ion in the organic phase was calculated by subtraction of the determined amount in the aqueous phase from the total amount present.…”

“…As part of our systematic work on the synergistic solvent extraction of lanthanoids, [1][2][3][4][5][6][7][8] we performed comparative studies aiming at (i) improving the extraction ability of b-diketone compounds by increasing their acidity, (ii) studying the dependence of the extraction properties on the number of the ligating groups on a calixarene scaffold and nally, (iii) understanding the role of the solvent for extraction, separation and synergism by comparing a traditional molecular solvent, chloroform, and one ionic liquid, namely 1-methyl-3-butylimidazolium bis(triuoromethanesulfonyl)imide, there-aer denoted as [C 1 C 4 im][Tf 2 N]. It is our opinion that the wellassessed strategy based on the individual independent improvements of the extractants used in a synergistic system, which has proven to be quite efficient in molecular solvents, [1][2][3][4][5][6][7][8] may nd some limitations in ionic liquids (ILs). Ionic liquids are studied for an increasing number of applications in various aspects of chemistry and of course liquid-liquid extraction of rare earths and other metals.…”

“…Second, calixarenes are a versatile class of supramolecular compounds widely exploited as molecular platforms for the introduction of specic ligating arms in a reorganized pattern suitable for metal ions complexation. [1][2][3][4][5][6][7][8][24][25][26] Depending on the nature of the ligating groups, on the dimension of the macrocyclic scaffold and on the hydrophobicity, calixarenes have shown immense selectivity in the separation of alkaline and alkaline earth ions, 27 heavy metals 28 and f-elements. 1,29 The latter and the tunable shape of the molecules make them ideal candidates for building blocks and molecular scaffolds in the design of new and more sophisticated ligands.…”

Synergistic Solvent Extraction of Lanthanides(III) with Mixtures of 4-Benzoyl-3-Methyl-1-Phenyl-5-Pyrazolone and Phosphoryl-Containing Podands

“…and neutral donor extractants (e.g. nitrogen-containing compounds, [4][5][6] sulfoxides, 7,8 crown ethers, 3,[9][10][11] diglycolamides, 12 neutral mono-and polydentate organophosphorus compounds, [13][14][15][16][17][18][19][20] etc.) has been studied.…”