The 1-acetyl-3-methyl-4-[3-methoxy-4-(4-methylbenzoxy)benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-one molecule investigated by a joint spectroscopic and quantum chemical calculations

• The compounds containing 1,2,4-triazol, their derivatives and synthesis.
• Antioxidant activities of the synthesized compound.
• FT-IR, micro-Raman and UV spectroscopies of the synthesized compound.
• Quantum chemical calculations of the synthesized compound.

In this study, the synthesis, spectroscopic (FT-IR, micro-Raman and UV–Vis) investigations and antioxidant activity of 1-acetyl-3-methyl-4-[3-methoxy-4-(4-methylbenzoxy)benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-one molecule have been verified. The quantum chemical computations (molecular structure, vibrational frequencies, electronic absorption maximum wavelengths in gas phase and ethanol solvent, HOMO–LUMO, molecular electrostatic potential (MEP) and natural bond orbital (NBO) analyses, nonlinear optical (NLO) and thermodynamic properties and atomic charges of the title compound have been performed using the DFT/B3LYP method with 6-31G(d) basis set. The energetic behavior of title molecule in different solvent media was investigated at the B3LYP/6-31G(d) level by using the integral equation formalism polarizable continuum model (IEFPCM). A comparison between the calculated results and experimental data exhibits a very good agreement.