Computational Studies and Fluorescent Turn‐off Sensing of Biologically Important Cu2+ Ion in Irrigation Water by Schiff Base

Abstract Numerous chemosensors have been reported for the detection of heavy metal ions in drinking water or in biological system pertaining to health concerns. Here, in the present study we have focused on synthesis of simple, efficient chemosensors for one of such ion i. e . Cu 2+ due to its prevalent importance. Chemosensor (3) has been synthesized from sulfanilamide and nitro‐benzaldehyde which was further characterized with various analyses such as 1 H NMR, 13 C NMR, FT‐IR and mass spectrometry. The absorbance and emission studies results showed that sensor (3) has profound sensitivity and selectivity for Cu 2+ ions in aqueous medium by quenching the emission intensity of the same at 335 nm. Whereas the complexation of sensor (3) with Cu 2+ ion produced the change in color from pale yellow to green, in semi aqueous medium with gradual addition of Cu 2+ . The sensor was also tested against various water samples and found to generate 100.4 % recovery from irrigation water sample. Further computational analyses were performed to verify the sensing mechanism and also different global quantities such as electron affinity ( A ), ionisation potential ( I ), electronegativity (χ), global softness ( S ), hardness ( η ), and electrophilicity ( ψ ) were calculated.