Intra- and inter-molecular interaction of 9-cis and all-trans retinal isomers in the 0.45 to 5.5 terahertz region
Abstract
Distinct characteristic spectra of two retinal isomers were obtained in the THz region. Changes in each of the isomer's absorption line assignment as well as variation in intensity were observed. Such changes were attributed to the difference in the extent of intra- and inter-molecular interaction of the isomers near the ground state condition. Density functional theory (DFT) calculations supported the assertion that the shift in the absorption peaks is caused by the difference in the extent of intramolecular interaction.