Exploration of Multi‐ions Recognition of Donor‐Acceptor Schiff Base Chemosensor and Application in Real Samples, DFT Calculation and Cell Imaging Studies

In this research work, an optical sensor based on donor‐acceptor Schiff base fluorescent chemosensor namely (E)‐4‐(4‐(diethylamino)‐2 hydroxy benzylidene amino)‐2‐(triflromethyl) benzonitrile) ( HL ) was successfully designed and developed for detecting three most essential and abundantly found elements namely Fe 3+ , Zn 2+ , and Cu 2+ . In absorption spectra, HL shows a drastic change in color with a possible to have naked eye detection with Fe 3+ whereas a noticeable isosbestic point was occurred with Zn 2+ . In emission spectra, fluorescence “on‐off” response with Zn 2+ and Cu 2+ was observed which indicates selectively senses of Zn 2+ and Cu 2+ . This sensor displays 2:1 stoichiometric ratio with metal ions by 1 H NMR titration, mass spectra and Job's plot. Moreover, the recyclability of HL was assessed through EDTA showing an efficient fluorescence “off‐on‐off” signal response. Furthermore, the (HL‐Zn 2+ ) ensemble formed was used for selective recognize MnO 4 − . HL achieved an INHIBIT logic function using different inputs and corresponding emission as output. The optimized structures of HL and complexes (HL‐Zn 2+ and HL‐Cu 2+ ) were used to understand spectral properties using DFT which further calculated different reactivity descriptors such as chemical hardness, chemical potential and electrophilicity index. This selective sensitivity of HL towards Zn 2+ were successfully studied and used for detection of Zn 2+ intracellularly in mouse breast adenocarcinoma cell.