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-1H-imidazol-1-yl)thiazol-4-yl)-2H-chromen-2-one (TCCM) was effectively synthesized and characterized through NMR and Mass spectrum. An approach towards the recognition of Cu²⁺ and Co²⁺ 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 Cu²⁺ and Co²⁺ ions with a limit of detection of 4.2 and 3.9 μM, respectively. It was discovered that the sensor was quite selective for Cu²⁺ and Co²⁺ ions that had a lot of competing ions. Further, the studies were supported by DFT analysis and NBO studies.