Novel chelating resins containing calix[4]pyrroles: Synthesis and sorptive properties

Chelating resins containing calix[4]pyrroles have been synthesized via: (i) immobilization of calixpyrrole on a polymeric support (VBC/DVB copolymer), (ii) condensation of calixpyrrole with formaldehyde, and (iii) radical copolymerization of calixpyrrole-monomer with methyl methacrylate and divinylbenzene. Insoluble, cross-linked material was obtained in all cases, bearing up to 1.03 mmol of calixpyrrole units per gram resin in case of resin 2. All resins demonstrated a preference for fluoride anions over other halides in static sorption studies in dry acetonitrile, complexing up to 96.5% of fluorides from 10−3 M solutions. Larger anions, like iodides, were not complexed by the resins due to lack of fit between the size of the ion and the size of the binding place. Thus obtained resins can be used as sorbents of anions from non-aqueous media and are promising materials for separation techniques.