Organic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands.
Phys Chem Chem Phys. 2011 Oct 6;13(37):16861-6. doi: 10.1039/c1cp21950b. Epub 2011 Aug 23.
Direct evaluation of the induced π current density in [5]paracyclophane (1) shows that, despite the significant non-planarity (α = 23.2°) enforced by the pentamethylene bridge, there is only a modest (ca. 17%) reduction in the π ring current, justifying the use of shielding-cone arguments for the assignment of (1)H NMR chemical shifts of 1 and the claim that the non-planar benzene ring in 1 retains its aromaticity (on the magnetic criterion).
直接评估[5]轮烷（1）中诱导的π电流密度表明，尽管五亚甲基桥强制产生了显著的非平面性（α = 23.2°），但π环电流仅适度降低（约 17%），这证明了屏蔽锥论点可用于分配 1 的 1H NMR 化学位移，并证明 1 中非平面苯环保留其芳香性（在磁标准上）。
