Synthesis, crystal structure, tautomerism, DFT calculations, nonlinear optical properties, and molecular docking studies of a novel schiff base: (Z)-3-(benzyloxy)-6-(((3-hydroxyphenyl)amino)methylene)cyclohexa-2,4-dien-1-one

Abstract In the present work, the compound imine tautomeric forms in solide state crystalise in keto-amine ( Z )-3 (benzyloxy)-6-(((3-hydroxyphenyl) amino)methylene) cyclohexa-2,4-dien-1-one ( I ). The compound was synthesized via the condensation reaction between the 4-benzyloxy-2-hydroxybenzaldehyde and 1-amino-3-phenol. It was characterized by single-crystal X-ray diffraction analysis, and by infrared, 1 H and 13 C, DEPT-135 and HSQC NMR spectroscopy technicals in powder and solution forms. UV-visible technical confirmed the tautomer phenomenon in different types of solvents. HS analysis and two-dimensional fingerprint plots were used to quantify the interatomic interactions present in the crystal. The molecular structure of compound I in its three tautomeric forms was investigated using DFT calculations at the ωB97X-D/6-311 + G(d) level. Our results exhibit excellent agreement with the optimized geometry and X-ray crystallography structure, with an RMSE of 0.358 Å for I1. Chemical reactivity analysis reveals that I2 is more stable than I1 and I3, and the compounds can be classified as moderate electrophiles. The interaction between the corrosion inhibitor and the copper surface is stronger than with the iron surface in both gas and aqueous phases. Additionally, the first hyperpolarizability decreases in the order I2 > I1 > I3, with $$\:{\beta\:}_{HRS}^{0}$$ values of 992, 557 and 427 a.u., respectively, surpassing the value of urea ( $$\:{\beta\:}_{HRS}^{0}$$ = 38 a.u.). These findings underscore the potential of the title compounds as promising candidates for nonlinear optical applications.