Sensitive recognition of cyanide through supramolecularly complexed new calix[4]arenes†
Abstract
Two new calix[4]arene based fluorescence sensors (L1 and L2) have been synthesized and characterized. L1 was found to selectively quench fluorescence intensity upon addition of Cu2+ ions through host–guest complexation and display “on–off” behavior while L2 was not that efficient. The in situ generated L1·Cu2+ complex could further recognize CN− from the anionic broth with a distinct “off–on” behavior in the fluorescence titration.