Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, New York 13244-4100, USA.
J Phys Chem A. 2010 Sep 9;114(35):9570-8. doi: 10.1021/jp105384x.
The influence of cocrystallized H(2)O molecules on the terahertz (THz) spectra and corresponding computational treatment of hydrated molecular crystals was investigated in the study of protonated and deuterium-substituted l-serine.H(2)O. The THz spectra of both solids have been measured in the range of 10 to 90 cm(-1), with simulations of the crystalline structure and THz vibrational modes performed using solid-state density functional theory. Significant and systematic overestimations of the predicted vibrational frequencies were observed in all calculations. Evidence provided by the comparison of the experimental and calculated vibrational frequencies for both the protonated and deuterated l-serine.H(2)O solids indicates the presence of significant anharmonicity in the observed lattice vibrations. The results suggest that vibrational anharmonicity may play a much larger role in the interpretation of the THz spectra of hydrates in contrast to their corresponding anhydrous forms.
研究了质子化和氘取代 l-丝氨酸。H(2)O 水合分子晶体中水合 H(2)O 分子对太赫兹 (THz) 光谱的影响及其相应的计算处理。两种固体的太赫兹光谱在 10 到 90 cm(-1)的范围内进行了测量，使用固态密度泛函理论对晶体结构和太赫兹振动模式进行了模拟。在所有计算中，观察到预测振动频率存在显著且系统的高估。对质子化和氘代 l-丝氨酸。H(2)O 固体的实验和计算振动频率进行比较提供的证据表明，观察到的晶格振动存在显著的非谐性。结果表明，与相应的无水形式相比，振动非谐性可能在水合物的太赫兹光谱解释中发挥更大的作用。
