A Complimentary Study of Calixarene Based Bifunctional Receptors for Alkali or Transition Metal Cations and Cr2o72- Anions

The article describes the syntheses and extraction properties of two new calixarene based receptors (3 and 4); the receptor 3 was synthesized from 25,27-diacetonyloxy-26,28-dihydroxy-5,11,17,23-tetra-tert-butylcalix [4] arene 2 by treatment with tetraethylene glycol ditosylate and then the compound 3 was converted to its Schiff base derivative 4 by refluxing 3 with 1,8-diamino-3,6-dioxaoctane. In the synthesis, the lower rim of p-tert-butylcalix[4]arene has been modified in order to acquire soft and hard binding sites for the recognition of metal cations and Cr2O7-2 selected alkali, transition metal cations and Cr2O7-2 anions are reported. It has been observed that receptor 4 is a better extractant 7 for all metal cations, but not selective as compared to the receptor 3. The protonated alkylinium form of 4 is an effective anions from an aqueous into a dichloromethane layer.