Theoretical Study on Infrared Vibration Spectrum of (SiO2)nO2H4
CAO Juan1,2,XU Can1,2*, ZHU Li-fang1,2,WANG Xi-min3
1. Key Laboratory for Magnetism and Magnetic Materials of the MOE, Lanzhou University, Lanzhou 730000, China 2. School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China 3. No.4 High School of Jingyuan Coal Company Limited, Baiyin 730913, China
Abstract：Infrared vibration spectra of nanosize (SiO2)nO2H4 with line, ring and cage structures were calculated using the density-functional theory (B3LYP) at 6-31G(d) level. For quasi 1D (one dimension) line and ring structure, the frequencies of stronger infrared vibration modes monotonically change as a function of the length, which shows strong size effect. The IR vibration modes in directions parallel and perpendicular to the axis of nanoline or nanoring have opposite size dependence trends, showing the real vibration anisotropy property of nano scale material. Due to constructional complexity, cage structure does not have quasi 1D character. Morever, IR vibration modes increase as structural symmetry decreases. Vibrations of two-membered ring, isolated hydroxyls of three structures and framework SiO4 tetrahedron in cage structure agree well with experimental data. Theoretical calculation result of IR spectra can be used to guide characterization of silicon oxide nano scale materials fabricated in experiment.
Key words：SiO2 nano material;Infrared spectrum;Density-functional theory
[1] Xu C, Wang W, Zhang W, et al. J. Phys. Chem. A, 2000, 104: 9518. [2] Chuang I S, Maciel G E. J. Am. Chem. Soc., 1996, 118: 401. [3] Du M H, Wang L L, Kolchin A, et al. Eur. Phys. J. D, 2003, 24: 323. [4] de Leeuw N H, Du Z, Li J, Yip S, et al. Nano Lett., 2003, 3: 1347. [5] Chiang C M, Zegarski B R, Dubois L H. J. Phys. Chem., 1993, 97: 6948. [6] Ceresoli D, Bernasconi M, Iarlori S, et al. Phys. Rev. Lett., 2000, 84: 3887. [7] Umari P, Gonze X, Pasquarello A. Phys. Rev. Lett., 2003, 90: 027401. [8] Bakaev V A, Steele W A. J. Chem. Phys., 1999, 111: 9803. [9] XU Can, ZHU Li-fang, GAO Chen-yang, et al(徐 灿, 朱莉芳, 高晨阳, 等). Acta Phys. Chim. Sin. (物理化学学报), 2006, 22(2): 152. [10] Wada K, Nakashita M, Bundo M. Chem. Lett., 1998, 1: 765. [11] Becke A D. Phys. Rev. A, 1988, 38: 3098. [12] Lee c, Yang W, Parr R G. Phys. Rev. B, 1998, 37: 785. [13] Frisch, M J, Trucks G W, Schlegel H B, et al. Gaussian 03, Revision C.02. Wallingford CT: Gaussian, Inc., 2004. [14] XU Can, CAO Juan, ZHU Li-fang, et al(徐 灿, 曹 娟, 朱莉芳, 等). Acta Phys. Chim. Sin.(物理化学学报), 2006, 22(4): 451. [15] Civalleri B, Garrone E, Ugliengo P. Chem. Phys. Lett., 1998, 294: 103. [16] WANG Juan, ZHANG Chang-rui, FENG Jian, et al(王 娟，张长瑞，冯 坚，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25, 1045. [17] XU Can, CAO Juan, GAO Chen-yang(徐 灿，曹 娟，高晨阳). Acta Phys. Sin.(物理学报)，2006，55(8)：4221. [18] XU Can, ZHANG Xiao-fang, CHEN Liang, et al(徐 灿，张小芳，陈 亮，等). Atca Phys. Chim. Sin.(物理化学学报)， 待发表.
