Vibrational and quantum chemical analysis of 3-methyl-2,6-diphenyl piperidin-4-one using HF and DFT methods

Abstract

Characterization of 3-methyl-2,6-diphenylpiperidin-4-one (MDPO) by quantum chemical calculations and spectral techniques has been performed with spectroscopic investigations like FT-IR, FT-Raman and UV techniques. Molecular geometries, FT-IR spectrum (4000-400 cm^-1) and FT-Raman spectrum (4000-100 cm^-1) in solid phase was recorded. The structural and spectroscopic data of the molecule were obtained from HF and B3LYP with 6-311++G(d,p) levels using density functional theory(DFT). The stability and intra-molecular charge transfer have been analyzed by the detailed natural bond orbital (NBO) analysis. The charge transfer occurring in the molecule was verified and found to be stable from smaller energy gap by HOMO-LUMO analysis. Atomic population analysis reveals the percentage of electron distribution in s-and p-subshells. The first order hyperpolarizability of the investigated molecule has been studied theoretically. The calculated results were applied to simulated infrared and Raman spectra of the title molecule which show good agreement with observed spectra.