Triphenylamine‐Based Dual Chemosensor for Cu²⁺ and Co²⁺ Ions and Volatile Acid Vapour Sensor, DFT Calculations

ABSTRACT In this work, a novel fluorescent chemosensor 3‐(2‐(2‐(4‐(diphenylamino)phenyl)‐4,5‐diphenyl‐1 H ‐imidazol‐1‐yl)thiazol‐4‐yl)‐2 H ‐chromen‐2‐one ( TCCM ) was effectively synthesized and characterized through NMR and Mass spectrum. An approach towards the recognition of Cu 2+ and Co 2+ ions using a turn‐off fluorescence technique was developed. The chemosensor TCCM also exhibited colorimetric and fluorometric sensing behaviour with a visible colorimetric response to trifluoroacetic acid (TFA). Upon the addition of TFA to TCCM , a new peak formation at 500 nm in the absorption spectra along with the visible colour change from colourless to brown. In addition, it exhibits high selectivity towards Cu 2+ and Co 2+ ions with a limit of detection of 4.2 and 3.9 μM, respectively. It was discovered that the sensor was quite selective for Cu 2+ and Co 2+ ions that had a lot of competing ions. Further, the studies were supported by DFT analysis and NBO studies.