An Unsymmetrical bis‐Imine Derivative for Solvent Dependent Rapid Optical Discrimination of Al³⁺, Zn²⁺ and OCl⁻: Combined Experimental and Theoretical Studies

Abstract

An unsymmetrical bis‐imine derivative (A2) selectively detect Al3+, Zn2+ and OCl− in a solvent dependent manner where Al3+ and Zn2+ emit green and blue light in DMSO−H2O media while OCl− emits green‐yellow light in aqueous ethanol. The corresponding florescence enhancements are 8.2 fold, 3.7 fold (chelation enhanced fluorescence and excited state intra‐molecular proton transfer OFF) and 10.6 fold (H‐bonding, excited state intra‐molecular proton transfer OFF) respectively. While the limit of detection (LODs) for Al3+, Zn2+ and OCl− are 49 nM, 35 nM and 74 nM respectively, the corresponding binding/ association constants are 1.79×105 M−1, 1.8×105 M−1 and 3.68×105 M−2. The results of density functional theory (DFT) studies are fairly close to that of experimental findings.