Ikemoto Koki, Lin Jennie, Kobayashi Ryo, Sato Sota, Isobe Hiroyuki
Department of Chemistry, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
JST ERATO Isobe Degenerate π-Integration Project, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
Angew Chem Int Ed Engl. 2018 Jul 9;57(28):8555-8559. doi: 10.1002/anie.201803984. Epub 2018 Jun 6.
A saddle-shaped macromolecule has been synthesized. The molecule was designed as a geodesic saddle with 1,3,5-trisubstituted benzene (named phenine) as the fundamental unit. The phenines were woven into a polygonal framework that was composed of 168 sp -hybridized carbon atoms. The saddle-shaped structure with unique symmetry showed atypical conformational changes. The biaryl linkages in this molecule had a small energy barrier for rotation, and these structural fluctuations resulted in seven H NMR resonances representing 84 aromatic hydrogen atoms. Nevertheless, the overall saddle shape of the molecule was persistent, and the "up" and "down" orientations of phenine moieties circulated to give average H resonances. The structural characteristics of this molecule, including the anomalous entropy-driven dimerization, may deepen our understanding of defect-rich graphitic sheets.
已合成出一种鞍形大分子。该分子被设计成以1,3,5-三取代苯（称为菲宁）为基本单元的测地线鞍。这些菲宁被编织成一个由168个sp杂化碳原子组成的多边形框架。具有独特对称性的鞍形结构显示出非典型的构象变化。该分子中的联芳基键具有较小的旋转能垒，这些结构波动导致代表84个芳香氢原子的七个¹H NMR共振峰。然而，分子的整体鞍形保持不变，菲宁部分的“上”和“下”取向循环，给出平均¹H共振峰。该分子的结构特征，包括异常的熵驱动二聚化，可能会加深我们对富含缺陷的石墨片的理解。
