Vibrational spectra and electrostatic potential surface of 2-fluoro-6-methoxybenzonitrile based on quantum chemical calculations

M. Murugan, V. Balachandran an

Abstract

In this work, the experimental and theoretical stud y on molecular structure and vibrational spectra of 2-fluoro-6- methoxybenzonitrile (FMBN) are studied. The FT-Rama n and FT-IR spectra of FMBN were recorded. Geometri cal parameters and vibrational wavenumbers are calculat ed using ab initio Hartree-Fock (HF) and Density Fu nctional Theory (DFT) levels employing the 6-31G(d,p) basis set. Comparison of the simulated spectra provides i mportant information about the ability of the computational method (B3LYP) to describe the vibrational modes. T he complete assignments are performed on the basis of the total energy distribution (TED). The molecular stability and bond strength were investigated by applying the Natural Bond Orbital (NBO) analysis. The calculated HOMO an d LUMO energies show that charge transfer occur in th e molecule. Information about the size, shape, char ge density distribution and site on chemical reactivity of the molecule was obtained by mapping electron density isosurface with Electrostatic Potential (ESP).