A naphthalimide-calixarene as a two-faced and highly selective fluorescent chemosensor for Cu2+ or F−

A new naphthalimide-calix[4]arene was synthesized as a two-faced and highly selective fluorescent chemosensor for Cu2+ or F−. This chemosensor displayed a selective fluorescence quenching effect only with Cu2+ among the various metal ions. On the other hand, among the various anions, the title chemosensor displayed a selective fluorescence quenching effect only with F−. The binding mode with F− was further investigated using fluorescence changes and 1H NMR experiments.