Substituted Benzalacetophenone Molecules: A Computational Investigation of Structural, PED & Non-Linear Optical Properties

This protocol presents a complete theoretical study on the substituted benzalacetophenone molecules. In this study, eighteen chalcone derivatives 1-18 were evaluated with respect to their first- and second-order hyperpolarizability parameters. For this purpose, the molecular geometries of 1-18 were optimized using set 631 g (d,p) and hybrid functional B3LYP. Spectroscopic characterizations for 1-18 were executed through the calculations of IR, UV-Vis, H-1 NMR and C-13 NMR spectra. The quantum chemical parameters such as chemical potential, chemical hardness, electronegativity and electrophilicity indexes were obtained using the frontier molecular orbital (FMO) energies. The potential energy distribution (PED) analysis was used to provide a detailed assignment of vibrational bands. Important contributions to electronic absorption bands from FMOs were also evaluated. The distribution of FMOs to the whole molecule was investigated to determine the nature of electronic charge transfers in the target structures. The static and dynamic first- and second-order hyperpolarizability parameters for 1-18 were calculated by using CAM-B3LYP/6-31++G(d,p). The static beta and gamma were calculated at the ranges of 1.348-2.967x10(-29) esu and 82.50-136.2x10(-36) esu. This wide range of beta and gamma values indicates that chalcone derivatives with rational substitution may be promising candidates for first- and second-order NLO applications. The findings of this study contribute to the understanding of the relationships between molecular structure and non-linear optical properties, thus paving the way for the design of new materials with improved non-linear optical properties.