An Experimental Study on the Effect of Substituents on Aromatic-Aromatic Interactions in Dithia[3,3]-metaparacyclophanes
作者:Jian Long Xia、Sheng Hua Liu、Franco Cozzi、Michele Mancinelli、Andrea Mazzanti
DOI:10.1002/chem.201103639
日期:2012.3.19
Simple model systems based on the 2,11‐dithia[3,3]‐metaparacyclophane skeleton were synthesized to study the effects of substituents on the intramolecular aromatic–aromatic interactions between benzene rings. X‐ray crystallography established that, in their more stable conformations, these metaparacyclophanes featured partially overlapping aromatic rings (interplanar distances of about 3.5 Å), with
合成了一个简单的基于2,11-二硫代[3,3]-间对环磷烷骨架的模型系统,以研究取代基对苯环之间分子内芳香-芳族相互作用的影响。X射线晶体学确定,这些亚对环芳烃具有更稳定的构型,具有部分重叠的芳环(平面间距约3.5Å),且芳族体系的平面排列呈略微倾斜的排列(平面角度范围为5– 19°)。计算表明,这些衍生物后行topomerization通过的翻转元在取代的环段替换一个环,这是两个环采用连续的边对面配置(包括正交的环配置)的过程,该配置比开始的面对面排列不稳定。异构化过程的能垒是通过变温NMR光谱法通过实验确定的,方法是使用内部温度标准评估能量的微小差异(相对实验误差:(±0.1 kJ mol -1)。相互作用环上不同取代基的功能很小,并且显然与取代基对π系统极性的影响无关,基于电荷渗透效应的解释似乎更适合于使观察到的趋势趋于合理化。障碍。