Experimental and density functional theory studies on (E)-2-[(2-(hydroxymethyl)phenylimino)methyl]benzene-1,4-diol

The Schiff base compound (E)-2-[(2-(hydroxymethyl)phenylimino)methyl]benzene-1,4-diol has been synthesized and characterized by 1H NMR, 13C NMR, IR, UV–Vis and single-crystal X-ray diffraction. Molecular geometry of the title compound in the ground state have been calculated using the density functional method (DFT) with 6-31G(d) basis set and compared with the experimental data. The calculated results show that the optimized geometry can well reproduce the crystal structure. By using TD-DFT method, electronic absorption spectra of the compound have been predicted and a good agreement with the TD-DFT method and experimental one is determined. The energetic behavior of the compound in solvent media has been examined using B3LYP method with the 6-31G(d) basis set by applying the polarizable continuum model (PCM). The total energy of the title compound decreases with increasing polarity of the solvent. In addition, DFT calculations of the compound, molecular electrostatic potential (MEP), natural bond orbital analysis (NBO) and non-linear optical (NLO) properties were performed at B3LYP/6-31G(d) level of theory.

► The compound was characterized by NMR, IR, UV-Vis and X-ray crystallography.
► Molecular geometry was determined by DFT method.
► The electronic properties, HOMO and LUMO energies were determined by TD-DFT method.
► The compound is a good candidate of nonlinear optical material.