Crystal Structure, Spectroscopic Investigations and Quantum Chemical Computational Study of 5-(diethylamino)-2-((3-nitrophenylimino)methyl)phenol

Abstract

The Schiff base compound, 5-(diethylamino)-2-((3-nitrophenylimino)methyl)phenol, C<inf>17</inf>H<inf>19</inf>O<inf>3</inf>N<inf>3</inf>, was synthesized and characterized by IR, UV–Vis and single-crystal X-ray diffraction (XRD) technique. The title compound prefers enol tautomeric form in solid state as to X-ray, IR and UV–Vis spectra results. Also, using the TD-DFT method, the electronic absorption spectra of the title compound was computed in both the gas phase and ethanol solvent. The calculated results support that the enol form is more stable than keto form. The molecular geometry from the X-ray single-crystal determination of the title compound in the ground state was compared at the B3LYP and B3PW91 levels of the density functional method (DFT) with the 6-311 + G(d,p) basis set. The harmonic vibrational frequencies of the title compound were calculated using the B3LYP and B3PW91 methods with the 6-311G+(d,p) basis set. The calculated results were compared with the experimental determination results of the compound. The potential energy surface scans about important torsion angels were performed by B3LYP/6-311 + G(d,p) level of theory for the title compound. The energetic behaviors of the title compound in the solvent media were also examined using the B3LYP and B3PW91 methods with the 6-311 + G(d,p) basis set applying the Onsager and the polarizable continuum model (PCM). Besides, the molecular electrostatic potential map (MEP), frontier molecular orbitals (FMO) analysis and thermodynamic properties for the title compound were obtained with the same levels of theory. The nonlinear optical properties (NLO) of the title compound were performed in the solvent media using the B3LYP and B3PW91 methods with the 6-311 + G(d,p) level using the PCM model. © 2016 Elsevier B.V.