Abstract
The article describes the syntheses and extraction properties of new alkylnitrile and alkylamino substituted calix[4]arene based copolymers. These compounds have been synthesized via nucleophilic substitution reactions involving 5,11,17,23‐tetra‐tert‐butyl‐25,27‐bis(cyanomethoxy)‐26,28‐dihydroxycalix[4]arene (3), or 25,27‐bis(cyanomethoxy)‐26,28‐dihydroxycalix[4]arene (4) with 1,5‐dibromopentane and bisphenol‐A, followed by their reduction with sodium borohydride in the presence of CoCl2 · 6H2O. In addition an oligomer containing pendant calix[4]arene units with nitrile functionalities on its lower rim has been synthesized via nucleophilic reaction involving 5,11,17,23‐tetra‐tert‐butyl‐25,27‐bis(cyanomethoxy)‐26,28‐dihydroxycalix[4]arene 3 with p‐dibromoxylene. The extraction properties of polymers 5–9 toward the HCr2O7 − anion are also reported. Due to the higher oxidative stability of nitrile groups, polymers 5–7 have been developed as good extractants for transferring the HCr2O7 − anion from an aqueous into a dichloromethane phase.
Acknowledgments
We are grateful the US National Science Foundation (NSF), the Welch Foundation and the Scientific and Technical Research Council of Turkey (TUBITAK) for the financial support of this work. We thank Dr. Bruce Moyer (ORNL) for helpful discussions.