Abstract
A calix[4]arene carboxylic acid derivative alternatively possessing benzoic acid and two acetic acid groups has been prepared to investigate the extraction behavior for the aluminum group of metals, such as aluminum, gallium, and indium from nitrate and chloride media and to compare with the tetraacetic acid derivative. The present extraction reagent exhibits a simple ion-exchange mechanism for all metals. Both extractants show that the selectivity series is In > Ga >> Al in nitrate media, while Ga > In >> Al is found for chloride media due to complexation of indium with chloride anions. The stoichiometry of the gallium complex with both extractants, determined by the continuous variation method, was determined to be 1 : 1. The complexation site of the present extractant for gallium was also determined using 1H-NMR spectroscopy. The extraction ability and separation efficiency of both extractants for the three metal ions were estimated by using the half pH values. Stripping of the metal ions loaded on the present extractant with hydrochloric acid was also investigated.
