Amine-derivatized calix[4]arenes for sensitive extraction of cupric ion and formation of amine radical cation

We report herein some calix[4]arene amine (C[4]A) derivatives, which are the copper(II)-induced fluorescence “turn-off” and “naked eye” chemosensors and the agents for the formation of amine radical intermediates. In this way, concurrently, the sensitive extraction of cupric ions and the formation of amine radical cations with calixarenes have been documented for the first time. These data were confirmed by using some experimental studies such as UV–visible, fluorescence, electron spin resonance, and cyclic voltammetric.