發(fā)布時間：2018-07-24 21:03

【摘要】：使用太赫茲時域光譜(THz-TDS)、傅里葉紅外光譜(FTIR)和傅里葉拉曼光譜(FT-Raman)技術(shù)在室溫下對γ-氨基丁酸(GABA)、苯甲酸(BA)及其研磨和溶劑共晶體進行表征分析。FTIR,FT-Raman及THz光譜都能夠分辨原料物質(zhì)及GABA-BA共晶體。其中THz實驗結(jié)果顯示了GABA-BA研磨和溶劑共晶體位于0.93,1.33,1.57THz的吸收峰明顯區(qū)別于原料物質(zhì),這體現(xiàn)了不同物質(zhì)在THz波段具有明顯的指紋特征。為確認GABA-BA共晶體的晶型結(jié)構(gòu),分別采用FTIR和FT-Raman光譜進行光譜歸屬。通過FTIR的光譜歸屬推斷GABA-BA共晶體由GABA中的氨基H_23和BA中的羰基O1構(gòu)成第一個氫鍵,氨基中的N18結(jié)合BA中的羥基H15形成第二個氫鍵。FT-Raman光譜中,原料物質(zhì)GABA中位于576,886,1 250,1 283,1 337,1 423和1 470cm~(-1)處歸屬于—CH_2,—NH_2彎曲振動的Raman散射峰在GABA-BA共晶體內(nèi)消失,判定GABA中的氮原子N18亦可作為氫鍵受體,從而驗證了GABA-BA共晶體的晶型結(jié)構(gòu)。此外,為了進一步說明溶劑pH值對GABA-BA共晶體的形成條件的影響,利用THz-TDS,FT-Raman光譜確認了該共晶體在溶劑條件2.00≤pH≤7.20可穩(wěn)定地生成。這一研究結(jié)果同時也為利用THz-TDS,FTRaman光譜技術(shù)辨別固體物質(zhì)晶型結(jié)構(gòu)、晶型形成條件提供了實驗及理論依據(jù)。
[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，

本文編號：2142651