title: Terahertz Spectroscopy of Biotin and Pyridoxine.
abstract: Terahertz (THz) absorption spectra of the biotin and pyridoxine were studied using Fourier transform infrared spectroscopy (FTIR) at room temperature. These spectra exhibit enhanced absorption in THz range because of strong intramolecular and intermolecular vibration modes. In the experiment, the samples were mixed with high density polyethylene powder, which was used as spectrophotometric grid. The absorption spectra show worse consistency at higher frequencies for the high ratio of the samples to polyethylene. It indicates that the absorbance of the biotin and pyridoxine increased with frequency. Molecular vibrational spectral calculations based on density functional theory (DFT) show strong correlation with the experiment. We investigated the absorption spectra of isolated molecules (single molecule, two molecules, three molecules) and unit cell of crystal to clarify the mechanism of the spectra change due to intramolecular and intermolecular vibration and rotation.
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Miao
authors.initials: M
authors.lastname: Li
authors.forename: Chun
authors.initials: C
authors.lastname: Li
authors.lastname: Sun Hai-jun
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Yun-fei
authors.initials: YF
authors.lastname: Liu
mesh_terms: D001710:Biotin; D011736:Pyridoxine; D017550:Spectroscopy, Fourier Transform Infrared; D055068:Terahertz Spectroscopy; D014732:Vibration
chemical_list: D001710:Biotin; D011736:Pyridoxine