Synthesis, Antioxidant Activity, Spectroscopic, Electronic, Nonlinear Optical (NLO) and Thermodynamic Properties of 2-Ethoxy-4-[(5-oxo-3-phenyl-1,5-dihydro-1,2,4-triazol-4-ylimino)-methyl]-phenyl-4-methoxybenzoate: A Theoretical and Experimental Study

In the present study, the synthesis, antioxidant activity, spectroscopic, electronic, and thermodynamic properties of 2-ethoxy-4-[(5-oxo-3-phenyl-1,5-dihydro-1,2,4-triazol-4-ylimino)-methyl]-phenyl-4-methoxybenzoate (EPM) were examined. The novel 2-ethoxy-4-[(5-oxo-3-phenyl-1,5-dihydro-1,2,4-triazol-4-ylimino)-methyl]-phenyl-4-methoxybenzoate (EPM) compound was successfully synthesized with novel derived biologically important 1,2,4-triazole Schiff base. This biologically active 1,2,4-triazole Schiff base was obtained through condensation of 3-phenyl-4-amino-4,5-dihydro-1 H -1,2,4-triazol-5-one with 2-ethoxy-4-formylphenyl-4-methoxybenzoate. The characterization of the obtained compound was identified utilizing FT-IR, UV–Vis, 1 H-, and 13 C-NMR spectroscopies. The antioxidant activities of the newly synthesized Schiff base were evaluated employing the Oyaizu, Dinis, and Blois techniques. The optimized molecular structure, vibrational frequencies, ultraviolet–visible spectrums, and nuclear magnetic resonance values of the newly synthesized Schiff base were assessed through the use of density functional theory (DFT) with standard B3LYP/6–311++G(d,p) level. The harmonic vibration peaks were performed via comparison of the scaled values with the experimental FT-IR spectrum. The nuclear magnetic resonance chemical shift values were determined by the gauge-independent atomic orbital (GIAO) method. The nuclear magnetic resonance chemical shift values of the newly synthesized Schiff base in various solvents were examined at B3LYP/6–311++G(d,p) level utilizing integral equation formalism polarizable continuum model (IEFPCM). The chemical shift values of EPM were computed and compared with experimental findings. The correlational analysis (R 2 ) and RMSD results were evaluated to demonstrate correction and accuracy between calculated and experimental parameters. The HOMO–LUMO orbital forms and their energies were determined. The molecular electrostatic potential (MEP), Mulliken atomic charges, electronic absorption maximum wavelengths, thermodynamic characteristics (i.e., entropy, thermal capacity, and enthalpy), and nonlinear optical (NLO) properties (i.e., the first hyperpolarizability and polarizability) of the newly synthesized Schiff base were investigated. The correlational analysis results indicated a strong relationship between experimental and theoretical findings. The metal chelating activity of the newly synthesized Schiff base and standards was observed