Far-infrared vibrational modes of DNA components studied by terahertz time-domain spectroscopy
Far-infrared vibrational modes of DNA components studied by terahertz time-domain spectroscopy
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DOI：
10.1088/0031-9155/47/21/319
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发表时间：
2002-11-07
影响因子：
3.5
通讯作者：
Jepsen, PU
中科院分区：
文献类型：
--
作者：
Fischer, BM;Walther, M;Jepsen, PU
广泛的有机分子的远红外介电函数主要是由构成分子的大部分原子的振动和与分子间氢键振动相关的运动决定的。由于它们的集体性质，这些模式对分子内和分子间结构高度敏感，从而提供了分子构象状态及其环境影响的独特指纹。我们演示了使用太赫兹时域光谱（THz- tds）来记录形成脱氧核糖核酸（DNA）构建块的四种核碱基和相应核苷的远红外（0.5-4.0太赫兹）介电函数。我们观察到许多不同的光谱特征，分子之间在频率依赖的吸收系数和折射率上都有很大的差异。借助密度泛函计算的结果，我们将观测到的共振解释为分子间氢键的振动。
The far-infrared dielectric function of a wide range of organic molecules is dominated by vibrations involving a substantial fraction of the atoms forming the molecule and motion associated with intermolecular hydrogen bond vibrations. Due to their collective nature such modes are highly, sensitive to the intra- and intermolecular structure and thus provide a unique fingerprint of the conformational state of the molecule and effects of its environment. We demonstrate the use of terahertz time-domain spectroscopy (THz-TDS) for recording the far-infrared (0.5-4.0 THz) dielectric function of the four nucleobases and corresponding nucleosides forming the building blocks of deoxyribose nucleic acid (DNA). We observe numerous distinct spectral features with large differences between the molecules in both frequency-dependent absorption coefficient and index of refraction. Assisted by results from density-functional calculations we interpret the origin of the observed resonances as vibrations of hydrogen bonds between the molecules.