Résumé:
A recent experimental study has allowed synthesis of a new organic nonlinear optical material 3-(4-
chlorophenyl)-1-(pyridin-3-yl)prop-2-en-1-one(CPP) with a high second harmonic generation efficiency.
We apply density functional theory (DFT, GGA and B3LYP) and Hartree-Fock (HF) methods to
calculate the vibrational wavenumbers. They are assigned with by using the potential energy distribution
method. The calculated first hyperpolarizability of the title compound is comparable with the reported
values of similar derivatives and 25 times that of the standard NLO material urea. The HOMOeLUMO
calculations lead to consider GGA-PBE as the best functional to determine the electronic band gap of CPP
molecule. We complete this study with assignment of the vibrational modes and perform a comparison
with the experimental results. The analysis of MEP map shows that the most reactive site of the CPP
molecule is the site containing the oxygen atom. Furthermore, because of the enhancement of molecular
vibration within the CPP molecule, the thermodynamic parameters are increasing with the increase of
temperature. The FTIR, Raman and NMR spectra are calculated using DFT approach and corroborate the
experimental available data.
