Abstract L-cysteine hydrochloride monohydrate crystals, C3H7NO2S·HCl·H2O, were studied by Raman spectroscopy as a function of pressure in a diamond anvil cell up to 6.2 GPa in the spectral range 3500−30 cm−1. From the analysis of the results, we inferred that the crystal is structurally stable in this pressure range. Some changes on the Raman spectra were observed for bands related to vibrational modes of the SH, NH3+, CH2, CCN, OH and COH units. These modifications were associated with conformational changes of the molecules in the unit cell undergone at high pressures. Comparing this behavior with those of L-cysteine, DL-cysteine and L-cysteine hydrochloride crystals in the same pressure range, we note greater stability for the hydrochloride monohydrate form. In the L-cysteine hydrochloride monohydrate crystal, the chloride ion and water molecule play an essential role in increasing the number of the hydrogen bonds, improving the structural stability of the crystal.

中文翻译：

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L-半胱氨酸盐酸盐一水合物晶体在高压下的振动特性

摘要 L-半胱氨酸盐酸盐一水合物晶体，C3H7NO2S·HCl·H2O，通过拉曼光谱在3500-30 cm-1 的光谱范围内作为金刚石砧室中压力高达6.2 GPa 的函数进行了研究。从结果分析中，我们推断晶体在该压力范围内结构稳定。对于与 SH、NH3+、CH2、CCN、OH 和 COH 单元的振动模式相关的谱带，观察到拉曼光谱的一些变化。这些修饰与承受高压的晶胞中分子的构象变化有关。将这种行为与相同压力范围内的 L-半胱氨酸、DL-半胱氨酸和 L-半胱氨酸盐酸盐晶体的行为进行比较，我们注意到盐酸盐一水合物形式的稳定性更高。在L-半胱氨酸盐酸盐一水合物晶体中，