Terahertz Spectroscopic Investigation of Crystalline β-D-Galactopyranose
ZHANG Tong-jun1,2,CAI Jin-hui2,ZHOU Ze-kui2
1. College of Information and Electrical Engineering, Shandong University of Science and Technology, Qingdao 266510, China 2. Department of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China
Abstract：In order to deeply understand the spectral characteristics of β-D-galactopyranose in the terahertz region, terahertz time-domain spectroscopy was used to measure the absorption coefficient and refractive index in the frequency range 0.3-3.0THz at room temperature, and Fourier transform infrared spectroscopy was also used to obtain the absorption spectrum between 1.5 and 19.5 THz. In parallel with the experimental study, the 6-311+G** basis set and density functional theory(DFT) were applied to obtain the structure and vibrational frequencies of the isolated β-D-galactopyranose molecule at in phase. The observed vibrational spectra were assigned according to the DFT calculations. Results show that the theoretical calculations are in good agreement with the experimental data except somewhat blue shifts due to the intermolecular interactions. The observed resonances at the high frequency above 6 THz originate from distinct intra-molecular vibrational modes, while at the low frequency below 6 THz the observed resonances are dominated by vibrations of hydrogen bonds between the molecules or phonon modes. The comparison of experimental and theoretical studies shows that far-infrared absorption features are highly sensitive to the structure and spatial arrangement of molecules.
Key words：β-D-galactopyranose;Terahertz time-domain spectroscopy;Fourier transform infrared spectroscopy;Density functional theory
[1] Yang L M, Weng S F, Ferraro J R, et al. Vibrational Spectroscopy, 2001, 25: 57. [2] GE Min, ZHAO Hong-wei, JI Te, et al(葛 敏，赵红卫, 吉 特, 等). Science in China, Ser.B(中国科学B辑), 2005, 35(6): 441. [3] Zhbankov R G, Firsov S P, Grinshpan D D, et al. Journal of Molecular Structure, 2003, 645: 9. [4] WANG Xiao-hong, ZHANG Liang-liang, HU Ying, et al(王晓红, 张亮亮, 胡 颖, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(3): 385. [5] ZHANG Tong-jun, CAI Jin-hui, ZHOU Ze-kui. Proceedings of Joint 31st International Conference on Infrared and Millimeter Waves and 14th International Conference on Terahertz Electronics, 2006. 504. [6] ZHANG Tong-jun, ZHANG Guang-xin, ZHOU Ze-kui. Proceedings of the 6th World Congress on Intelligent Control and Automation, 2006. 5200. [7] ZHOU Ze-kui, ZHANG Tong-jun, ZHANG Guang-xin(周泽魁, 张同军, 张光新). Process automation Instrumentation(自动化仪表), 2006, 27(3): 4. [8] SUN Jin-hai, SHEN Jing-ling, ZHANG Cun-lin, et al. Chinese Physics Letters, 2005, 22(12): 3176. [9] GE Min, ZHAO Hong-wei, ZHANG Zeng-yan, et al(葛 敏, 赵红卫, 张增艳, 等). Acta Phys. Chim. Sin.(物理化学学报), 2005, 21(9): 1063. [10] HU Ying, WANG Xiao-hong, GUO Lan-tao, et al(胡 颖, 王晓红, 郭澜涛, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(6): 1008. [11] CHENG Jian-bo, XU Wei-qing, ZHAO Bing, et al(程建波, 徐蔚青, 赵 冰, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(5): 854. [12] WANG Wei-ning, YUE Wei-wei, YAN Hai-tao, et al. Chinese Science Bulletin, 2005, 50(21): 1561. [13] Shi Y L, Wang L. Journal of Physics D: Applied Physics, 2005, 38: 3741. [14] Longchambon F, Ohanessian J, Avenel D, et al. Acta crystallogrphica: Section B, 1975, 31: 2623. [15] Brown G M, Levy H A. Acta Crystallogrphica: Section B, 1979, 35: 656. [16] Wells H A, Atalla R H. Journal of Molecular Structure, 1990, 224: 385.
