A Bifunctional Chromogenic Calix[4]arene Chemosensor for Both Cations and Anions: A Potential Ca2+ and F– Switched INHIBIT Logic Gate with a YES Logic Function

A bifunctional chromogenic calix[4]arene 3, which contains both triazoles and hydroxy azophenols as both cationic and anionic recognition sites and the azophenol moiety as a coloration unit, was designed and synthesized. The recognition of Ca2+ by 3 gave rise to a marked colour change from greenish to bright yellow, whereas the recognition of F– by 3 showed a colour change from light green to bluish. The colour changes of 3 by the inputs of Ca2+ and F– have been implemented to construct a combinational logic circuit at the molecular level.