NMR Study of Hydrothermal Reactions of Dichloromethane with and without Alkali.
NMR Study of Hydrothermal Reactions of Dichloromethane with and without Alkali.
复制标题
二氯甲烷有碱和无碱的水热反应的核磁共振研究。
DOI：
10.1246/bcsj.73.2687
复制
发表时间：
2000
影响因子：
4
通讯作者：
M. Nakahara
中科院分区：
文献类型：
--
作者：
Y. Yamasaki;H. Enomoto;N. Yamasaki;M. Nakahara
通过使用间歇反应器（例如高压釜和密封玻璃管），在 150-300 °C 的温度范围内，研究了相当浓缩（约 1 M；M = mol dm-3）二氯甲烷 CH2Cl2 的水热反应，无论是否有碱。在室温下获取 1H、2H 和 13C NMR 谱作为反应时间的函数，以分析淬灭的反应物、中间体和产物。在 2 M NaOH 存在下，250 °C 下 270 分钟和 300 °C 下 60 分钟即可完全脱氯。歧化产物HCOO-分解产生CO、CO2和H2等气态副产物。在没有碱的情况下，CH2(OH)2 可以通过 1H 和 13C NMR 检测到，作为 CH2Cl2 水解的中间体，然后形成甲醇和甲酸根离子等 Cannizzaro 产物。从水解中间体CH2(OH)2 的角度讨论了CH2Cl2 的水热反应机理。
Hydrothermal reactions of considerably concentrated (ca. 1 M; M = mol dm-3) dichloromethane, CH2Cl2, were investigated with and without alkali in the temperature range of 150—300 °C by using batch reactors, such as an autoclave and sealed glass tubes. 1H, 2H, and 13C NMR spectra were taken at room temperature as a function of reaction time to analyze the quenched reactants, intermediates, and products. In the presence of NaOH at 2 M, the complete dechlorination was achieved in 270 min at 250 °C and in 60 min at 300 °C. Such gaseous by-products as CO, CO2, and H2 were generated by the decomposition of the disproportionation product, HCOO-. Without alkali, CH2(OH)2 could be detected by 1H and 13C NMR as an intermediate in the hydrolysis of CH2Cl2, before such Cannizzaro products as methanol and formate ion were formed. The mechanism of the hydrothermal reactions of CH2Cl2 is discussed in terms of the hydrolysis intermediate, CH2(OH)2.