Extraction of metal ions from water with tetrapyrazolic macrocycles found to Merrifield resin and silica gel

Two macrocyclic tetrapyrazolic compounds having internal cavities of differ ent sizes of were covalently bound both to a porous silica gel and to a Mer rifield resin. The ability of these sorbents to extract heavy and akali met al ion from water by a solid-liquid extraction process was studied and comp ared to results of classical liquid-liquid extraction with the unbound pyra zole compounds. The grafting at the surface of silica does not affect the c omplexing properties of the ligands. However, the hydrophobic nature of the Merrifield resin has a marked effect, especially on the selectivity of ext raction between the alkali metals. (C) 2000 John Wiley & Sons, Inc.