Vibrational spectra analysis, NBO, HOMO-LUMO, and nonlinear optical behavior studies on 3-(3,4-dimethoxyphenyl)-1-(pyridin-2-yl)prop-2-en-1-one

A combined experimental and theoretical study on molecular structure, vibrational spectra, HOMO-LUMO analysis, and hyperpolarizability of organic nonlinear optical crystal 3-(3,4-dimethoxyphenyl)-1-(pyridin-2-yl)prop-2-en-1-one is reported. Vibrational wavenumbers with Raman intensities and infrared absor ption intensities have been calculated in the ground state by the density functional theory method using 6-31G(d,p) basis set and Becke's three-parameter hybrid functional (B3LYP). Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis. The natural bond orbital analysis was performed to study the intramolecular bonding, interactions among bonds, and delocalization of unpaired electrons. Electrostatic potential surface and HOMO-LUMO are reported along with global reactivity descriptors. First, hyperpolarizability of the molecule was also calculated and nonlinear behavior of the molecule analyzed using computed data.