作者:Tadeusz Polonski、Maria J. Milewska、Andrzej Katrusiak
DOI:10.1021/ja00077a045
日期:1993.12
suhstituted N-nitrosopyrrolidines were prepared and their chiroptical spectra studied. The circular dichroism of monocyclic compounds depends on substituents, solvents, and temperature changes. Some of these N-nitrosamines exhibit bisignate CD curves in the region of n-π * transition. On the contrary, conformationally restrictcd bi- and tricyclic compounds show monosignate Cotton effects, the magnitudes
制备了几种取代的 N-亚硝基吡咯烷并研究了它们的手性光谱。单环化合物的圆二色性取决于取代基、溶剂和温度变化。这些 N-亚硝胺中的一些在 n-π * 跃迁区域表现出双信号 CD 曲线。相反,构象受限的双环和三环化合物表现出单信号棉花效应,其大小几乎与溶剂无关。双标志 CD 曲线是由处于平衡状态的吡咯烷环的两个半椅构象异构体产生的,并有助于相反的 CD 符号。棉花效应迹象可以通过我们之前制定的“降低对称性”扇区规则来预测