Molecular structure, vibrational spectra, UV–vis, NBO, and NMR analyses on nevirapine using ab initio DFT methods

Nevirapine is an anti-human immunodeficiency virus (HIV) agent that belongs to the class of the non-nucleosideinhibitors of the HIV-1 virus reverse transcriptase. Spectral characteristics of nevirapine have been probed into bymethods of Fourier transform infrared (FTIR), FT-Raman, UV-visible, and quantum chemistry. The UV spectrum wasmeasured in methanol. In order to gain some valuable insight into the recorded spectrum, the quantummechanical calculations were performed for nevirapine using both ZINDO and time-dependent density functionaltheory at B3LYP/6-31G(d,p) level. The optimized molecular geometry, bond orders, natural bond order analysis, andharmonic vibrational wavenumbers of nevirapine were calculated by restricted Hartree-Fock and density functionalB3LYP methods with the 6-31G(d,p) basis set using Gaussian 03 W program. The harmonic vibrational frequenciescalculated have been compared with experimental FTIR and FT-Raman spectra. The restricted Hartree-Fock anddensity functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, andit was used for assigning the 13C and 1H NMR chemical shifts of nevirapine.

Keywords:

FTIR , FT-Raman and UV spectra , ab initio DFT , Nevirapine , Chemical shift