Synthesis of a series of dichloroamino- and dihalosulfonamido-1,3,5-triazines and investigation of their hindered rotation and stereodynamic behaviour by NMR spectroscopy
作者:Stuart A. Brewer、Helen T. Burnell、Ian Holden、Brian G. Jones、Colin R. Willis
DOI:10.1039/a808753i
日期:——
Mono-substituted 1,3,5-triazines (s-triazines) have been prepared and characterised by NMR spectroscopy. The room temperature 13C NMR spectra of dichloroamino-s-triazines show three signals for the triazine ring, clearly indicating that C(2) and C(3) are in inequivalent environments. At elevated temperatures, two of the signals broaden and coalesce. Conversely, a number of dihalosulfonamido-s-triazine compounds were found to display only one signal for C(2) and C(3), indicating that the degree of π-bonding in the exocyclic C–N bond in these compounds is less significant. The low temperature exchange limits for the dihalosulfonamido-s-triazine compounds are reported.
我们制备了单取代的 1,3,5-三嗪(s-三嗪),并利用核磁共振光谱对其进行了表征。二氯氨基-s-三嗪的室温 13C NMR 光谱显示三嗪环有三个信号,清楚地表明 C(2) 和 C(3) 处于不等价的环境中。温度升高时,其中两个信号会变宽并聚合在一起。相反,一些二卤磺酰胺基-s-三嗪化合物的 C(2) 和 C(3) 只显示一个信号,这表明这些化合物中外环 C-N 键的π键程度不太明显。报告了二卤磺酰胺基-s-三嗪化合物的低温交换极限。