氯磺丙脲Ⅰ型与Ⅲ型的红外、拉曼及太赫兹光谱研究

Experimental Study and DFT Calculation of FTIR,FT-Raman and THz-TDS Spectra of Ⅰ and Ⅲ Polymorphs of Chlorpropamide

使用FTIR,FT-Raman和太赫兹时域光谱(terahertz time-domain spectroscopy,THz-TDS)技术在室温下对氯磺丙脲的Ⅰ型与Ⅲ型进行分析与表征。结果显示氯磺丙脲Ⅰ型与Ⅲ型在三种光谱中都表现出明显的差异。红外光谱与拉曼光谱中,Ⅰ型与Ⅲ型的光谱差异主要是吸收峰峰位的移动和峰强的改变;此外,在拉曼光谱中Ⅲ型在100~1 800cm^(-1)的特征峰明显多于Ⅰ型;太赫兹光谱中,Ⅰ型在0.90,1.09和1.29THz处有特征峰,而Ⅲ型在0.92,1.11,1.23和1.63THz处有特征峰,尤其是1.63THz处的一个强峰,明显区别于Ⅰ型。采用密度泛函理论(DFT)对氯磺丙脲两种晶型进行分子模拟,模拟结果与实验光谱较好吻合,同时模拟结果也表明氯磺丙脲Ⅰ型与Ⅲ型在0.9和1.1THz处的多分子振动模式相同,可以为氯磺丙脲其他晶型的太赫兹谱归属提供参考。该结果为药物多晶型的IR,Raman以及太赫兹光谱研究提供了依据。

The absorption spectra of Ⅰ and Ⅲ polymorphs of chlorpropamide were measured with terahertz time-domain spectroscopy（THz-TDS）technique,FT-IR and FT-Raman at room temperature.The results showed that there were distinct differences of Ⅰ and Ⅲ polymorphs of chlorpropamide in those spectra.The IR spectra of two polymorphs of chlorpropamide had showed differences both in the frequencies of the vibrational bands and in the relative band intensities.The obvious differences in Raman spectra of polymorphs of chlorpropamide were that the characteristic peaks ofⅢ-form were more than Ⅰ-form in 100~1 800cm^（-1） region.Absorption peaks observing in the terahertz spectra of Ⅰ-form were at 0.90,1.09 and 1.29 THz and Ⅲ-form were at 0.92,1.11,1.23 and 1.63 THz.The maximum difference between Ⅰ-form and Ⅲ-form was that the strong peak appeared at 1.63 THz of Ⅲ-form.The characteristic absorption bands of two polymorphs of chlorpropamide were assigned based on the simulation results of DFT calculation.The simulation result is in accordance with the experiment.From simulation results,it is found that the vibration modes of Ⅰ-form and Ⅲ-form were similar in IR and Raman spectra,but there were more differences in terahertz spectra.The study can provide experimental and theoretical references for the application of FT-IR,FTRaman and THz-TDS spectra techniques to detect pharmaceutical polymorphs.