sign corresponding to the n-pi* electronic transition. The optically active nitrosamines are configurationally labile compounds and gradually racemize in solution but they are indefinitely stable in the solid state. The first-order kinetics of the racemization in solution allowed us to assign the N-N rotation barriers by simple polarimetric measurements.
通过与旋光性二醇(TADDOLs)的夹杂物结晶,仅由于绕NN键旋转受阻而具有手性的几种
N-亚硝基哌啶被拆分为对映体。客体亚
硝胺的绝对构型是从包合物的X射线晶体结构推导出来的。通过主体二醇与
哌嗪的竞争络合释放包封的亚
硝胺。拆分的亚
硝胺的旋光性由其CD光谱显示。提出了一个简单的手性规则,以合理化观察到的对应于n-pi *电子跃迁的Cotton效应信号。旋光性亚
硝胺是结构不稳定的化合物,并在溶液中逐渐消旋,但在固态中它们无限稳定。