Effects of Enol-imine/Keto-amine tautomerism and conformational changes on the electronic spectra of a novel 1,2,4-triazole ortho-hydroxyaryl Schiff base in different solvents

•Electronic spectra (absorbance; fluorescence) were studied in different solvents.•Solvents’ polarity and acidity/basicity have a great influence on the spectra.•Conformational changes and tautomerism influence decisively the spectral properties.•Photoinduced enol-imine/keto-amine tautomerism takes place upon UV excitation.