Behavior of mixed systems based on para-substituted 4-aroyl-5-pyrazolones in the presence of phosphorus containing calix[4]arene towards lanthanoids: Synergistic solvent extraction and separation

摘要

Synergistic solvent extraction of selected trivalent lanthanoids (La, Nd, Eu, Ho and Lu) with mixtures of a chelating extractants (HL), either 4-(4-fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one (HPMFBP) or 3-methyl-4-(4-methylbenzoyl)-1-phenyl-pyrazol-5-one (HPMMBP) and 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis-(dimethylphosphinoylmethoxy)calix[4]arene (S) in CHCl3 from chloride medium has been studied. The interaction between the extractants in deuterochloroform has been examined by ~1H, ~(13)C and ~(31)P NMR spectra. The composition of the extracted species has been established as LnL3HL (HL and L~- represent either HPMFBP or HPMMBP and their anions, respectively). It has found that, in the presence of the phosphorus-containing calix[4]arene, the lanthanoids were extracted as LnL3S. On the basis of the experimental data, the values of the equilibrium constants have been calculated. The influence of the para-substituted 4-aroyl-3-methyl-1-phenyl-pyrazol-5-ones on the extraction process has been discussed. The synergistic enhancement and separation factors between metals have been evaluated.