Structure, Conformation, and Stereodynamics of <i>N</i>-Nitroso-2,4-diaryl-3-azabicyclo[3.3.1]nonanes and <i>N</i>-Nitroso-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones<sup>1</sup>
作者:Tadeusz Połoński、Marzena Pham、Maria J. Milewska、Maria Gdaniec
DOI:10.1021/jo9600159
日期:1996.1.1
(1)H, (13)C, and (19)F NMR spectra were measured for the title N-nitrosamines. The observed unusually low N-N rotation barriers (12-15 kcal/mol) result from a significant deviation of the nitrosamino system from planarity. A pyramidal character of the amino nitrogen was confirmed by the X-ray crystal structures of two compounds and by bathochromic shifts of the n-pi absorption bands in the UV spectra
测量了标题N-亚硝胺的可变温度(1)H,(13)C和(19)F NMR光谱。观察到的异常低的NN旋转势垒(12-15 kcal / mol)是亚硝胺系统与平面度的显着偏差造成的。两种化合物的X射线晶体结构以及UV光谱中n-pi吸收带的红移均证实了氨基氮的金字塔特征。亚硝氨基部分的非平面性是由于NNO基团与固定在双环骨架赤道位置的相邻芳基取代基之间的空间相互作用而引起的强拟假A((1,3))应变所致。另外,在低于“冻结”所需的温度下检查了芳基CC旋转的障碍。