Chromogenic sensing, biological, and optical properties of Schiff bases of 2-amino-6-methoxybenzothiazole.

• Schiff Base with methoxy and both methoxy - bromine showed higher antioxidant activity. • All studied compounds are a colorimetric sensor for F−, CN−, AcO−, H 2 PO 4 − and OH− anions under UV lamp and daylight. • Performed fluorescence measurements showed that the compounds ligand and including NO 2 group showed emission signal. • The triplet state of studied compounds ligand and with methoxy and with NO 2 group individually is observed. In this study, a new series of Schiff base benzothiazole derivatives were synthesized and their structures were characterized by elemental analysis, FTIR, UV–VIS and NMR spectroscopy. The biological, sensory and photophysical properties of the benzothiazole derivatives were investigated. The sensing properties of the compounds were investigated UV–VIS spectroscopically, calorimetrically and theoretically. All compounds showed colorimetric, fluorometric and spectroscopic sensor properties for F−, CN−, AcO−, H 2 PO 4 − and OH− anions. Furthermore, DNA binding, DNA cleavage and antioxidant activities of compounds 1 - 4 were investigated. All compounds affected pBR322 DNA both hydrolytically and oxidatively, interacted with DNA in electrostatic mode, and also compounds 1 and 2 exhibited antioxidant activity close to standard BHT. In addition, the effects of electron donating and accepting substituents on the emission properties and charge transfer dynamics were investigated by fluorescence and femtosecond transient absorption spectroscopy measurements, respectively. According to fluorescence measurements, compounds 3 and 4 showed emission signal, while compounds 1 and 2 showed fluorescence quenching and weaker emission signal. [ABSTRACT FROM AUTHOR]