Third-Order Nonlinear Optical Properties of a Carboxylic Acid Derivative.

We report a study of the structural and electrical properties of a carboxylic acid derivative (CAD) with structural formula C5H8O2 ((E)-pent-2-enoic acid). Using the M∆ller-Plesset Perturbation Theory (MP2) and the Density Functional Theory (DFT/CAM-B3LYP) with the 6-311++G(d,p) basis set the dipole moment, the linear polarizability and the first and second hyperpolarizabilities are calculated in presence of static and dynamic electric field. Through the supermolecule approach the crystalline phase of the carboxylic acid derivative is simulated and the environment polarization effects on the electrical parameters are studied. Static and dynamic estimation of the linear refractive index and the third-order nonlinear susceptibility of the crystal are obtained and compared with available experimental results. The characteristic vibrational modes and functional groups present in CAD were analyzed by Fourier Transform Infrared Spectrum (FTIR) in the region of 400-4000 cm-1. Through the Hirshfeld surface analysis the molecular structure and the vibrational modes properties of the CAD crystal are explored. The effects of solvent medium on the molecular properties are taken into account through the Polarizable Continuum Model (PCM). Also, the frontiers molecular orbitals, the band gap energy, and the global chemical reactivity descriptors are discussed. All the properties studied suggest that the present material may be considered for nonlinear optical material.