Diiminic Schiff bases: An intriguing class of compounds for a copper-nanoparticle-induced fluorescence study

摘要

The condensation products of salicylaldehyde and different diamines constitute an important class of diiminic Schiff bases (DSBs). This class of compounds has been rediscovered as reducing as well as capping agents under UV irradiation. UV irradiation of alkaline DSB solutions in the presence of water-soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Intriguing CuNP-stimulated fluorescence behavior of the solution has been observed. Depending upon the nature of the spacer in between two iminic bonds, fluorescence enhancement or quenching is observed. Such surprising fluorescence contrast has been ascribed to far-field radiation and lossy surface waves. Making light of things: UV irradiation of alkaline diiminic Schiff base (DSB) solutions in the presence of water-soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Fluorescence enhancement of the exposed DSBs was observed in the presence of in situ produced Cu~0 (see figure).