Selective mass transfer of iron(III) in supported liquid membrane using highly acidic extractants, 3-phenyl-4-acyl-5-isoxazolones

Ion-size recognition of three trivalent metal ions (Fe(III), Al(III), Cr(III)) with 3-phenyl-4-acyl-5-isoxazolones derivatives has been studied by the liquid-liquid extraction method. The diffusion of the corresponding complexes with Fe(III) in supported liquid membrane (SLM) system has been evaluated. It was found that the selectivity improves as the 4-acyl groups become bulkier. This improvement could be attributed to the narrowed distance between the two donating oxygens (“bite size”). The comparison of transport experiments of Fe(III) ions by the three acylisoxazolones having different bite size and acidity has showed best results with 3-phenyl-4-benzoyl-5isoxazolone.

The ability of acylisoxazolone derivatives HL1–HL3 as carriers in the transport across a supported liquid membrane was studied only for Fe(III). In fact, the extraction of Al(III) and Cr(III) The investigation by extraction method of the ions Fe(III), Al(III), Cr(III) has showed that the distance do-o and the acidity of these compound plays a central role in the separation of these ions, but for Al(III) and Cr(III) the extraction times are very long in comparison with Fe(III). Therefore, transport experiments have been carried out only with Fe(III). Among all carriers studied in this work, HL3 is the best carrier for Fe(III) ions. The order of transport ability reflects the acidity values of the acylisoxazolones, i.e.HL3>HL1>HL2.