Intriguing Fluorescence Behavior of Diiminic Schiff Bases in the Presence ofin situProduced Noble Metal Nanoparticles

Diiminic Schiff bases (DSBs) with a variety of spacers in between the two imine bonds have been prepared from salicylaldehyde and different diamines. Gold and silver nanoparticles (NPs) are photoproduced as stable hydrosol from the respective metal salts in the presence of alkaline DSBs. In solution, the capping capability of DSBs renders stability toward both the NPs. The phenomenon of capping of noble metal by DSBs is gifted with surprising alteration of the fluorescence property of DSBs. Varying concentration of the local field on the fluorophore as well as the coupling between the molecular dipole of the fluorophore and the surface plasmon band of the metal have been ascribed to be the key point of these stunning phenomena in solution phase.