在线红外光谱研究乌洛托品成盐机理

发布时间：2018-07-17 01:15

【摘要】：为了解乌洛托品(HA)和硝酸(NA)体系的成盐反应过程,明确成盐机理,采用在线红外技术跟踪监测分析了HA与NA生成乌洛托品一硝酸盐(HAMN)和乌洛托品二硝酸盐(HADN)过程中主要官能团特征吸收峰随时间的变化,用计算化学方法研究了HA与NA之间的相互作用。结果表明,在HA的成盐过程中,HNO_3与HA生成HAMN的反应很快,而HAMN到HADN的反应相对较慢。当硝酸达到5.97 mol·L~(-1)时,才有HADN生成。在HAMN红外光谱中,1002,1236,690,806 cm_(-1)处出现了颠倒峰,这些峰为HA中C—N键的特征吸收峰。由于生成了HAMN,引起了C—N键的力常数的改变,在倒峰左右两边对应处出现了波数为979,1024,1219,1259 cm~(-1)的吸收峰。当有HADN析出时,不滴加硝酸,依然有HADN生成并析出,且溶液中硝酸的量呈现缓慢上升趋势。在HAMN生成在过程中,HAMN吸附了周围的硝酸分子,当有HADN生成时,释放硝酸分子到溶液中,供给HAMN分子继续反应生成新的HADN分子。用高斯软件得到了HA和NA、HA与H_2O的优化结构和计算结合能值,显示HA的硝酸体系更稳定,该结果与实验结果一致。
[Abstract]:In order to understand the process of salt formation in the system of urotropine (HA) and nitric acid (na), the mechanism of salt formation was clarified. The changes of the absorption peaks of the main functional groups during the formation of urotropin-nitrate (HAMN) and urotonin dinitrates (HADN) from HA and na were analyzed by on-line infrared technique. The interaction between HA and na was studied by computational chemistry. The results showed that HNO3 reacted quickly with HA to produce HAMN in the process of HA salt formation, but the reaction from HAMN to HADN was relatively slow. When nitric acid reached 5.97 mol L ~ (-1), HADN was produced. The inversion peaks appeared at 1236690806 cm _ (-1) in HAMN infrared spectrum. These peaks are characteristic absorption peaks of C-N bond in HA. As a result of the formation of HAMN, the force constant of C-N bond is changed, and an absorption peak with a wave number of 979 ~ 1024 ~ 121919 ~ (59) cm ~ (-1) appears at the left and right sides of the inverted peak. When there is HADN precipitation, there is still HADN formation and precipitation without dropping nitric acid, and the amount of nitric acid in the solution shows a slow upward trend. During the formation of HAMN, HAMN adsorbs the surrounding nitric acid molecules. When there is HADN formation, the nitric acid molecules are released into the solution and the supply molecules continue to react to form new HADN molecules. The optimized structure and calculated binding energy of HA, NAHA-H _ 2O and H _ 2O were obtained by Gao Si software. The results show that the nitric acid system of HA is more stable, and the results are in agreement with the experimental results.
【作者单位】：中北大学化工与环境学院;
【分类号】：O657.33;TQ560.1

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