Di-AZOCALIX[4]ARENE DERIVATIVES

Nine series of chromogenic mono- (A1-A2) and di- (B1-B7) substituted azocalix[4]arene analogues containing more than one azo group were described. Different chelating agents like ester and ketone moieties were grafted on the lower rim position of azocalix[4]arenes. The selective extraction properties of Fe3+ cation were studied by liquid-liquid extraction. This extraction process was carried out by using compounds A1-A2 and B1-B7. The results proved that coupling of phenylazo groups onto the upper rim of azocalix[4]arenes yielded greater efficiency and selectivity for carrying the Fe3+ cation in the extraction process at pH 2.2