文摘
The synergistic solvent extraction of three selected lanthanoid ions (Ce3+, Eu3+, and Lu3+) with 4-(4-fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one or 3-methyl-4-(4-methylbenzoyl)-1-phenyl-pyrazol-5-one (HL) in combination with N,N-diisobutyl-2-(octylphenylphosphoryl)acetamide (CMPO) or 5,11,17,23-tert-butyl-25,26,27,28-tetrakis(dimethylphosphinoylmethoxy)calix[4]arene, (C4) in four ionic liquids of the imidazolium family [C1Cnim][Tf2N], (n = 4, 6, 8, and 10) has been investigated. The interaction between the extractants in deuterochloroform has been studied by 1H, 13C, and 31P NMR spectra and NOESY. On the basis of the experimental data, the values of the distribution ratios have been calculated. The log D values decrease as a function of n, i.e. with a trend following that of the hydrophobicity of ILs’ cations: 4 > 6 > 8 > 10 using the chelating ligand with the bulkier substituent (−CH3). The influence of the para-substituted 4-acylpyrazolone and the synergistic agent on the extraction process have been discussed. A synergistic effect less than 1 order of magnitude occurs in the extraction of Ln(III) ions with mixtures of HL and CMPO or C4. The values of separation factors of Eu/Ce and Lu/Eu pairs have been evaluated.
