Synthesis and properties of an aza-coumarin based sensor for detection of Zn2+, Cd2+ and Cu2+

Abstract

By condensation of 7-(dimethylamino)-2-oxo-2H-benzo[b][1,4]oxazine-3-carbaldehyde (T1) and 2-aminomethylpyridine, an aminal NC-1 rather than a Schiff base was synthesized. The synthetic mechanism was likely to be determined by stabilizing effect of intramolecular hydrogen bond, which was proved through density functional theory (DFT) calculations and control molecules NC-2~NC-4. Furthermore, the spectroscopic tests indicated that NC-1 behaves as a fluorescent probe for sensing Cd2+, Zn2+ and Cu2+ by different fluorescence and color changes which can be observed by naked eyes.