Multistate/multifunctional switches based on photochromic Schiff base.

The salicylidene Schiff base derivative, namely, N-salicylidene-(S)-alpha-naphthylethylamine (SNEA) has been synthesized to study the characterization of multistate/multifunctional switches. Upon the stimulations of optical inputs (UV light and visible light) and chemical inputs (pH and Zn(2+)), SNEA undergoes reversible photochromism, deprotonation and complexation reactions. In this case, four chemical species are involved. These interconversions of SNEA between four states have been systematically investigated by the absorption and the emission spectra. Spectroscopic studies indicate that the photochromic switch, pH switch and fluorescent switch can be realized using the single molecular entity of SNEA.