Department of Physics, School of Sciences, Nanchang University, Xuefu Avenue 999, Nanchang City 330031, China.
Department of Physics, School of Sciences, Nanchang University, Xuefu Avenue 999, Nanchang City 330031, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Aug 5;236:118346. doi: 10.1016/j.saa.2020.118346. Epub 2020 Apr 6.
Carbamazepine cocrystals with nicotinamide, saccharin and fumaric acid were synthesized and characterized by time-domain terahertz spectroscopy. Lattice vibrations of cocrystals with their individual constituents were investigated by means of the dispersion-corrected density functional theory with and without cell parameter constraints. The simulated THz spectra successfully reproduce the features of all the crystals in their experimental spectra. A better agreement between experimental and theoretical THz spectra is achieved when the cell parameter constraints are applied in geometry optimization. Some intensive modes of neat carbamazepine and cocrystals were discussed in terms of the motions of hydrogen bonds. The effect of lattice vibration on these cocrystallizations was further examined to gain insights into the thermodynamics. It is found that lattice vibration is favorable for all these cocrystal formations.
采用时域太赫兹光谱法合成了卡马西平与烟酰胺、糖精和富马酸的共晶，并对其进行了表征。通过无和有晶胞参数约束的色散校正密度泛函理论研究了共晶与其各组成部分的晶格振动。模拟的太赫兹光谱成功地再现了所有晶体在实验光谱中的特征。当在几何优化中应用晶胞参数约束时，实验和理论太赫兹光谱之间的一致性得到了更好的改善。根据氢键的运动，讨论了纯卡马西平和共晶的一些强模。进一步考察了晶格振动对这些共晶化的影响，以深入了解热力学。结果发现，晶格振动有利于所有这些共晶的形成。
