Complexing Behavior of New Naphthalene Derivatives Having Amide Groups as Fluorescent Chemosensors for Alkali and Alkaline Earth Metal Ions

New naphthalene derivatives (1NSN, 1NLN, 1NE and 1NcrownN) as fluorescent chemosensors for metal ions using excimer emission were synthesized. We investigated the metal ion recognition of 1NSN, 1NLN, 1NE and 1NcrownN. Large changes in the fluorescence spectra of not only 1NSN and 1NLN but also 1NE were observed with the addition of magnesium ion. However, changes in the fluorescence spectra of 1NcrownN were not observed with the addition of alkali and alkaline earth metal ions.