Selective Extraction of Fe3+ Cation by Calixarene-Based Cyclic Ligands

Abstract

The selective liquid-liquid extraction of Fe³⁺ cation from the aqueous phase to the organic phase was carried out by using p-tert-butylcalix4]arene L₁], ca-lix4]arene L₂], p-nitro-calix4]arene L₃], calix4]arene p-sulfonic acid L₄], p-(diethylamino)methylcalixt4]arene L₅], tetramethyl-p-tert-butylcalix4]arene tet-raketone L₆], 25,27-dimethyl-26,28-dihydroxy-p-tert-butylcalix4]arene diketone L₇], calix4]arene-bearing dioxime group on the lower rim L₈], and a monooxime L₉]. The effect of varying pH upon the extraction ability of calixarenes substituted with electron-donating and electron-withdrawing groups at their p-position was examined. Observed results were compared with those found for unsubstituted calix4]arene.