In this work, the density functional theory (DFT) calculation combined with a polarizable continuum model (PCM) was used to study the solvent media effects on the electrical and geometrical behaviors of the Schiff-base derivative, (E)-4-[({4-[(pyridin-2-ilmetilideno)amino]phenyl}amino)-metil]fenol (EPAF). The linear and nonlinear optics parameters, as the dipole moment, linear polarizability, and first and second hyperpolarizabilities, were calculated at DFT/B3LYP/6-311+G(d) level, for the EPAF molecule in several solvent media. The dynamic behavior of the Hyper-Rayleigh Scattering (HRS) first hyperpolarizability was studied as function of the electric field frequency. The results presented for HRS first hyperpolarizability suggest that the studied crystal has good nonlinear optical properties. In addition, the gap energy was calculated from the HOMO-LUMO energies difference in several solvent media. The EPAF crystal intermolecular interactions were studied by the Hirshfeld surface analysis. The third-order electric susceptibility χ(3) of the crystal EPAF was also calculated, indicating the EPAF crystal as a promising candidate for NLO applications in photonic and optoelectronic devices.

The use of organic as nonlinear optical materials has been intensively explored in the recent years due to the ease of manipulation of the molecular structure and the synthetic flexibility regarding the change of substituent groups. In the present work, the linear and nonlinear properties of two chalcones derivatives (E)-1-(4-methylphenyl)-3-phenylprop-2-en-1-one (4MP3P) and (E)-1-(4-Nitrophenyl)-3-phenylprop-2-en-1-one (4NP3P), that differ by the substituent position at the phenyl ring, were studied in the presence of protic and aprotic solvents simulated by the Polarizable Continuum Model (PCM) at DFT/B3LYP/6-311+G(d) level. The static and dynamic (1064 nm) molecular parameters as the dipole moment, linear polarizability, first and second hyperpolarizabilities were studied as function of the solvent dielectric constant value. The geometrical behavior as the chemical bond angles, torsion angles, and partial charges distribution of the compounds were studied, including calculations of gap energies in various solvents. The obtained results revealed that the substituent change of CH3 (4MP3P) to NO2 (4NP3P) benefits the nonlinear optical properties of the compounds in the presence of the solvent media, the absolute values of the parallel first hyperpolarizability were the ones that present the greater variation.