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利用太赫兹时域光谱(Terahertz time-domain spectroscopy,THz-TDS)技术对呋喃妥因、尿素及其研磨和溶剂共晶体进行表征分析,实验结果显示了呋喃妥因和尿素的研磨和溶剂共晶体位于0.85、1.23、1.60 THz的吸收峰明显区别于原料物质.该结果表明太赫兹光谱技术可以有效鉴别呋喃妥因、尿素及其共晶体.运用密度泛函理论(Density functional theory,DFT)对呋喃妥因和尿素共晶体的2种可能结构进行了结构优化和光谱模拟,模拟结果显示其中的结构A在0.49、0.81、1.25、1.61 THz处具有吸收峰,与实验结果较吻合.推断共晶体氢键的形成位置为尿素中的氨基H6和呋喃妥因上的酰胺基O30,该处形成第一处氢键,而呋喃妥因的酰胺基H31和尿素上的羰基O1形成第二处氢键.同时结合理论模拟结果对呋喃妥因和尿素共晶体分子振动模式进行归属.
The characterization of nitrofurantoin, urea and their milled and solvent cocrystals was performed by means of Terahertz time-domain spectroscopy (THz-TDS). The experimental results showed that both mofetil and urea co-crystals were ground at 0.85 and 1.23 , The absorption peak of 1.60 THz is obviously different from that of the raw materials.The results show that terahertz spectroscopy can effectively identify nitrofurantoin, urea and its eutectic.Using density functional theory (DFT), nitrofurantoin and urea co-crystal 2 The results show that the structure A has absorption peaks at 0.49, 0.81, 1.25 and 1.61 THz, which are in good agreement with the experimental results.It is deduced that the formation position of hydrogen bond in eutectic is urea Amino H6 and nitrofurantoin O30, where the formation of the first hydrogen bond, and nitrofurantoin H31 and urea carbonyl O1 form the second hydrogen bond. Simultaneously with the theoretical simulation results of nitrofurantoin and urea co-crystal molecules Vibration mode is assigned.