Simple imine linked colorimetric and fluorescent receptor for sensing Zn2+ ions in aqueous medium based on inhibition of ESIPT mechanism

Herein, we report the highly selective binding of Zn2+ ion by the salicylaldimine based Schiff base chromogenic receptor 1 [(N,N′-bis (salicylidine)-o-phenylenediamine]. Receptor 1 senses Zn2+ ion in aqueous medium by colorimetric and fluorescent response in the presence of other metal ions like Pb2+, Hg2+, Sn2+, Cd2+. Receptor 1 on binding with Zn2+ ion exhibits fluorescence enhancement which is due to the inhibition of the (ESIPT) mechanism.