Novel Mg2+-responsive fluorescent chemosensor based on benzo-15-crown-5 possessing 1-naphthaleneacetamide moiety

A new fluorescent ionophore for Mg2+, 4′-(1-naphthaleneacetamido)benzo-15-crown-5 (1), was synthesized, and its complexation behavior in acetonitrile was investigated by means of UV and fluorescence spectrometry. In the absence of a metal ion, the naphthalene moiety showed quite weak fluorescence emission (fluorescence ‘Off’ state). On the other hand, after the addition of Mg2+, fluorescence emission from the naphthalene moiety increased (fluorescence ‘On’ state).