Synthesis and molecular modelling of new donor-π-acceptor benzothiazole-carbazole-pyridine-based fluorescent chromophore

• The benzothiazole-carbazole-pyridine dye (ThCzPy) was synthesized and characterized by IR, 1 H/ 13 C NMR and Mass spectroscopy. • The DFT molecular modeling presented a nonplanar structure of the synthesized derivative. • The emission of chromophore ThCzPy exhibited valuable Stokes’ shift ( Δ ν ¯ = 4653 cm −1 ). • The chromophore inhibited E. coli and K. pneumoniae bacteria, with MIC values < 124 µg/mL and < 51 µg/mL, respectively. The targeted benzothiazole-carbazole-pyridine dye ( ThCzPy ) was synthesized using a synthetic approach completed by the condensation of 6-(benzothiazol-2-yl)-3-formyl-9-hexyl-9 H -carbazole ( 4 ) with 4-aminopyridine ( 5 ). The absorption and emission spectra of the chromophore ThCzPy , in DMSO, displayed good Stokes’ shift ( Δ ν ¯ = 4653 cm −1 ). The DFT configuration of the frontier molecular orbits in gas and solvated ground state (S o ) were compared to the solvated excited state (S 1 ). Furthermore, the new chromophore’s antimicrobial efficacy was evaluated as minimum inhibitory concentration (MIC) against a panel of Gram’s positive, negative, and fungi using ampicillin and fluconazole as reference drugs, where it exhibited comparable activity. The SwissADME study revealed that ThCzPy has a bioavailability score 0.55 and meets Lipinski’s criteria for drug similarity.