Characterization of Crystal Chirality in Amino Acids Using Low-Frequency Raman Spectroscopy.
Characterization of Crystal Chirality in Amino Acids Using Low-Frequency Raman Spectroscopy.
复制标题
使用低频拉曼光谱表征氨基酸晶体手性。
DOI：
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发表时间：
2017
影响因子：
2.9
通讯作者：
Y. Tischler
中科院分区：
文献类型：
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作者：
Hagit Aviv;I. Nemtsov;Y. Mastai;Y. Tischler
本文提出了一种区分外消旋晶体和对映体纯晶体的新方法。最近，光学滤波器的发展使得能够容易地使用拉曼光谱来检测低频振动（LFV）模式。在这里，我们第一次使用拉曼光谱来表征由手性分子组成的结晶有机材料的LFV模式。外消旋和对映体纯晶体的LF-拉曼光谱表现出显着的变化，我们归因于不同的手性晶体结构中的氢键网络。在一组代表性的氨基酸中，我们观察到，当比较外消旋晶体与对映体纯晶体时，可用的LFV模式及其相对散射强度是侧链极性的强函数。因此，LF-拉曼可以用作与目前使用的表征晶体手性的方法互补的方法，这是由于更简单、更快和更灵敏的测量，沿着所需的小样品尺寸，其受到焦点中的激光束直径的限制。
We present a new method for differentiating racemic crystals from enantiopure crystals. Recently, developments in optical filters have enabled the facile use of Raman spectroscopy to detect low-frequency vibrational (LFV) modes. Here, for the first time, we use Raman spectroscopy to characterize the LFV modes for crystalline organic materials composed of chiral molecules. The LF-Raman spectra of racemic and enantiopure crystals exhibit a significant variation, which we attribute to different hydrogen-bond networks in the chiral crystal structures. Across a representative set of amino acids, we observed that when comparing racemic versus enantiopure crystals, the available LFV modes and their relative scattering intensity are strong functions of side chain polarity. Thus, LF-Raman can be used as a method that is complementary to the currently used methods for characterizing crystal chirality due to simpler, faster, and more sensitive measurements, along with the small sample size required, which is limited by the laser-beam diameter in the focus.