γ-氨基丁酸和苯甲酸共晶体及其形成条件的振动光谱分析
发布时间：2018-07-24 21:03
【摘要】：使用太赫兹时域光谱(THz-TDS)、傅里叶红外光谱(FTIR)和傅里叶拉曼光谱(FT-Raman)技术在室温下对γ-氨基丁酸(GABA)、苯甲酸(BA)及其研磨和溶剂共晶体进行表征分析。FTIR,FT-Raman及THz光谱都能够分辨原料物质及GABA-BA共晶体。其中THz实验结果显示了GABA-BA研磨和溶剂共晶体位于0.93,1.33,1.57THz的吸收峰明显区别于原料物质,这体现了不同物质在THz波段具有明显的指纹特征。为确认GABA-BA共晶体的晶型结构,分别采用FTIR和FT-Raman光谱进行光谱归属。通过FTIR的光谱归属推断GABA-BA共晶体由GABA中的氨基H_23和BA中的羰基O1构成第一个氢键,氨基中的N18结合BA中的羟基H15形成第二个氢键。FT-Raman光谱中,原料物质GABA中位于576,886,1 250,1 283,1 337,1 423和1 470cm~(-1)处归属于—CH_2,—NH_2弯曲振动的Raman散射峰在GABA-BA共晶体内消失,判定GABA中的氮原子N18亦可作为氢键受体,从而验证了GABA-BA共晶体的晶型结构。此外,为了进一步说明溶剂pH值对GABA-BA共晶体的形成条件的影响,利用THz-TDS,FT-Raman光谱确认了该共晶体在溶剂条件2.00≤pH≤7.20可稳定地生成。这一研究结果同时也为利用THz-TDS,FTRaman光谱技术辨别固体物质晶型结构、晶型形成条件提供了实验及理论依据。
[Abstract]:Terahertz time domain spectroscopy (THz-TDS), Fourier transform infrared spectroscopy (FTIR) and Fourier Raman spectroscopy (FT-Raman) were used to characterize (GABA), benzoic acid (BA) and its grinding and solvent eutectic at room temperature. FTIRFT-Raman and THz spectra can be distinguished. Raw material and GABA-BA eutectic. The experimental results of THz show that the absorption peak of GABA-BA lapping and solvent eutectic is obviously different from that of the raw material at the peak of 0.93 ~ 1.33 THz, which shows that the different substances have obvious fingerprint characteristics in the THz band. In order to confirm the crystal structure of GABA-BA eutectic, FTIR and FT-Raman spectra were used for spectral assignment. It is inferred from the spectral attribution of FTIR that GABA-BA eutectic consists of amino H _ S _ 23 in GABA and carbonyl O _ 1 in BA to form the first hydrogen bond, while N _ (18) in amino group binds to hydroxyl H _ (15) in BA to form a second hydrogen bond. In the raw material GABA, the scattering peak of Raman, which belongs to GABA-BA eutectic, belongs to the flexural vibrational Raman scattering peak located at 1 283C 1 423 and 1 470 cm ~ (-1). It is determined that the nitrogen atom N18 in GABA can also be used as a hydrogen bond receptor, thus validating the crystal structure of GABA-BA eutectic. In addition, in order to further explain the influence of solvent pH value on the formation conditions of GABA-BA eutectic, it is confirmed by THz-TDS FT-Raman spectra that the eutectic can be formed stably under the solvent condition of 2.00 鈮，
本文编号：2142651
[Abstract]:Terahertz time domain spectroscopy (THz-TDS), Fourier transform infrared spectroscopy (FTIR) and Fourier Raman spectroscopy (FT-Raman) were used to characterize (GABA), benzoic acid (BA) and its grinding and solvent eutectic at room temperature. FTIRFT-Raman and THz spectra can be distinguished. Raw material and GABA-BA eutectic. The experimental results of THz show that the absorption peak of GABA-BA lapping and solvent eutectic is obviously different from that of the raw material at the peak of 0.93 ~ 1.33 THz, which shows that the different substances have obvious fingerprint characteristics in the THz band. In order to confirm the crystal structure of GABA-BA eutectic, FTIR and FT-Raman spectra were used for spectral assignment. It is inferred from the spectral attribution of FTIR that GABA-BA eutectic consists of amino H _ S _ 23 in GABA and carbonyl O _ 1 in BA to form the first hydrogen bond, while N _ (18) in amino group binds to hydroxyl H _ (15) in BA to form a second hydrogen bond. In the raw material GABA, the scattering peak of Raman, which belongs to GABA-BA eutectic, belongs to the flexural vibrational Raman scattering peak located at 1 283C 1 423 and 1 470 cm ~ (-1). It is determined that the nitrogen atom N18 in GABA can also be used as a hydrogen bond receptor, thus validating the crystal structure of GABA-BA eutectic. In addition, in order to further explain the influence of solvent pH value on the formation conditions of GABA-BA eutectic, it is confirmed by THz-TDS FT-Raman spectra that the eutectic can be formed stably under the solvent condition of 2.00 鈮，
本文编号：2142651
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