Extraction of rhodium(III) by a bisacylated diethylenetriamine derivative from hydrochloric acid solutions

The extraction of rhodium(III) with a bisacylated diethylenetriamine derivative from hydrochloric acid solutions was studied. Optimum conditions for rhodium(III) extraction were determined. It was found that, at a contact time to 10 min, the extraction occurred by an ion-association mechanism. At a contact time longer than 10 min, rhodium(III) was extracted by a mixed mechanism with the insertion of an extractant molecule into the inner coordination sphere of the rhodium(III) ion. The composition of the extracted compound was determined using electronic, 1H and 13C NMR, and IR spectroscopy and elemental analysis, and the structure of this compound was proposed.