Spectroscopic Studies of Cholesterol: Fourier Transform Infra-Red and Vibrational Frequency Analysis

The present paper deals with the experimental and theoretical study on the vibrational spectra of cholesterol molecule. The vibrational and electronic transition analysis of the molecule was performed using Fourier Transform Infra-Red (FT-IR) spectroscopy and UV-Vis spectroscopy. FT-IR spectra were recorded in the spectral regions of 400-4000 cm-1 and the UV-Vis absorption spectrum of the molecule has been recorded in powder form using UV-Vis spectrophotometer in the spectral region 190-1400 nm. The optimized geometry with 6311G (d, p) basis set is used to determine the vibrational spectra of the molecule using Gaussian 09 software. The vibrational harmonic frequencies are scaled using a scale factor, yielding a good agreement between the experiment and the theory. The Mulliken atomic charges have also been computed. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule.