Synthesis of polymer-supported calix[4]arenes and selective extraction of Fe3+

Three polymeric calix[4]arenes were synthesized by reacting chloromethylated polystyrene with 25,26,27-tribenzoyloxy-28-hydroxy calix[4]arene (2a, 3a) and polyacryloyl chloride with 25,26,27,28-tetraacetoxy calix[4]arene (4a). After alkaline hydrolysis of the polymers, they were utilised for selective extraction of some transition metal cations from aqueous phase to organic phase. It was found that the polymeric calix[4]arenes were selective to extract Fe3+ from an aqueous solution which contained Cu2+, Ni2+, Co2+, and Fe3+ cations and it was observed that the polymer supported onto the lower rim calix[4]arene is a more efficient carrier of Fe3+ in the extraction process.