Structure and vibrational spectroscopic study of alpha-tocopherol

Abstract We report here the vibrational and structural analysis of alpha-tocopherol. The vibrational analysis has been accomplished experimentally by infrared and Raman spectroscopic techniques and theoretically by density functional theory. Two conformers of alpha-tocopherol have been optimized with the help of density functional theory. Energy minimized structures have been further used for vibrational frequencies calculations. Calculated values of molecular parameters of both the conformers have been comparable with the available experimental values in literature. All the observed vibrational bands have been assigned with the help of potential energy distribution calculations and intensity patterns of the simulated spectra. The ultraviolet–visible spectrum has been reported in wavelength range of 200 nm–500 nm. Observed ultraviolet–visible bands have been assigned to various electronic transitions, which have also been calculated using time dependent density functional theory.