Through-space interactions between face-to-face, center-to-edge oriented arenes:: importance of polar-π effects
Through-space interactions between face-to-face, center-to-edge oriented arenes:: importance of polar-π effects
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DOI：
10.1039/b208871a
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发表时间：
2003-01-07
影响因子：
3.2
通讯作者：
Siegel, JS
中科院分区：
文献类型：
--
作者：
Cozzi, F;Annunziata, R;Siegel, JS
本文合成了两组构象受限的多环化合物（1-3和4-7），作为研究面对面、中心到边缘（平行偏移）取向芳烃之间通过空间相互作用的模型体系。这些化合物在一个相互作用的环上具有不同的X取代基。通过2D [H-1，H-1] EXSY NMR谱监测1-7中芳基-芳基键周围旋转的DeltaG（不相等）随X的变化，发现从供电子到吸电子取代衍生物的势垒增加。量子力学计算[MP2/DVZ (2d,p)//B3LYP/DVZ(2d,p)]给出了与实验数据一致的势垒值及其变化。结果与静电效应主导的排斥芳烃-芳烃相互作用一致。
Two series of conformation ally restricted polycyclic compounds (1-3 and 4-7) have been synthesized as model systems for studying the through-space interactions between face-to-face, center-to-edge (parallel-offset) oriented arenes. These compounds feature different X substituents on one of the interacting rings. By monitoring the variation of the DeltaG(not equal) for the rotation around the aryl-aryl bond in 1-7 as a function of X by 2D [H-1,H-1] EXSY NMR spectroscopy, it was found that the barriers increase on passing from electron-donating to electron-withdrawing substituted derivatives. Quantum mechanical calculations [MP2/DVZ (2d,p)//B3LYP/DVZ(2d,p)] gave barrier values and variations in agreement with the experimental data. The results are consistent with a repulsive arene-arene interaction dominated by electrostatic effects.