第35卷，第10期 2015年10
光谱学与光谱分析 Spectroscopy and Spectral Analysis
Vol.35,No.10-pp2946-2951
October,2015
Terahertz Spectroscopy of Biotin and Pyridoxine
JIANG Ling, LI Miao', LI Chun', SUN Hai-jun
XU L?, LIU Yun-fei*
1. College of Information Science and Technology , Nanjing Forestry University , Nanjing210037, China 2. Advanced Analysis and Testing Center, Nanjing Forestry University , Nanjing 210037 , China
Abstract Terahertz (THz) absorption spectra of the biotin and pyridoxine were studied using Fourier trans form 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 ahsorp tion 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 spec-tral 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 .
Keywords Fourier transform infrared spectroscopy : Biotin Pyridoxine : DFT method
中图分类号：0657.3
Introduction
文献标识码：A
D0I; 10. 3964 /i. issn. 1000-0593 (2015 )10-2946-06
demonstrated to have similar sensitivity as THz time domain spectroseopy (TDS) in the low frequency THz region . Be-side low-frequency THz range , the far-infrared at higher fre-
Terahertz (THz ) spectra exhibit absorptions that are characteristic of the three-dimensional arrangement and low frequency motions of the atoms in a molecule, and are also sensitive to the molecule's interaction with its environment. In the low frequency range between O and 10 THz , non-cova-lent, intermolecular interactions such as electrostatic, Van der Waals and hydrogen bonds are dominated . To investigate the impact of hydrogen bonding + we measured and modeled the THz absorption spectra of two kinds of vitamin : biotin and py ridoxine .
Fourier transform infrared spectroscopy (FTIR ) is a use-ful method for evaluating the optical properties of materials and biological molecules in infrared range, which has been
Received : 2014-10-21 ; accepted : 2015-02-08
quencies , middle-infrared and near-infrared region are very important to study the molecular vibrations and determine the presence of certain characteristic groups in biological mole-cules[2. 3] , which can be measured by FTIR spectroscopy -
We studied the THz spectra of two kinds of vitamin , i. e ., biotin and pyridoxine by using FTIR spectroscopy . Allis et al . investigated the assignment of the low-frequency THz absorption signatures in the biotin] . Korter et al. employed continuous-wave T Hz spectroscopy to study the impact of me-chanical anharmonicity and temperature dependence on the ab-sorption spectra of the biotin[5.] , Above research mainly fo-cuses on the investigation of low-frequency characteristic of the biotin below 3 THz , and made few study on the mecha-
Foundation item : the National Natural Science Foundation of China under Contracts 31170668 and 31200541 , by the Natural Science Founda
tion of Jiangsu province under contract BK2012417 , by the Priority Academic Program Development of Jiangsu Higher Edu-cation Institutions (PADD)
Biography : JIANG Ling , (1979—), female, Associate professor in College of Information Science and Technology , Nanjing Forestry University
Corresponding author
e-mail : lyl@ njfu .edu -en