CATIONITES BASED ON CALIX[4]RESORCINARENE DERIVATIVES

Abstract

Novel network polymers possessing cation-exchange properties have been synthesized by the catalytic resol polycondensation of calix[4]resorcinarene derivatives with formaldehyde or with furfural and formaldehyde. The ion-exchange capacities of the polymers with respect to Na⁺, Me₄N⁺, Et₄N⁺, Bu₄N⁺cations have been determined. It is shown that the potentiometric titration curves of the polymers are similar to the titration curve of the resorcinol-formaldehyde resin, but they are shifted toward lower pH values and have inflections. The formation enthalpies of calix[4]resorcinarene derivatives and their salts with Na⁺, Me₄N⁺have been calculated by the MNDO/PM3 method. The heat of the reaction simulating the interaction of the polymers with NaOH and Me₄NOH has been determined. It is found out that the inflections of the potentiometric titration curves of the cationites appear when appreciable differences in the changes of the enthalpies of modeling reaction stages are observed.

ACKNOWLEDGMENTS

The authors would like to thank the Russian Foundation for Basic Research for financial supporting of this work (project No. 00-03-32589).

Notes

^#Quantum-chemical calculations were made by the MNDO/PM3 method using the CS MOPAC Std program (version 3.5) with a full optimization of the geometric parameters.

^##Geometric and energy parameters of the structures are presented on the Internet at http://www.kemsc.ru/chemistry.