Synthesis and Complexation Behavior of 2-[N, N-Bis (1-naphthylmethyl)-aminomethyl]-18-crown-6

Abstract

2-[N, N-Bis(l-naphthylmethyl)-aminomethyl]-18-crown-6 (3) gave intramolecular exciplex fluorescence, showing that the excited naphthalene chromophore was quenched by the nitrogen atom in the armed crown unit. The ann~ crown ether (3) was found to display unique photophysica1 properties in the presence of metal salts. Complexation of 3 with Zn 2 + increased the fluorescence intensity of the host by a factor of 2.4. IH and l3C NMR analyses of this complexation behavior revealed that Zn 2 + strongly coordinates with the anned crown nitrogen to cause a dramatic decrease in an intramolecular charge-transfer character.