A grossly warped nanographene and the consequences of multiple odd-membered-ring defects
A grossly warped nanographene and the consequences of multiple odd-membered-ring defects
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DOI：
10.1038/nchem.1704
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发表时间：
2013-09-01
期刊：
影响因子：
21.8
通讯作者：
Itami, Kenichiro
中科院分区：
文献类型：
--
作者：
Kawasumi, Katsuaki;Zhang, Qianyan;Itami, Kenichiro
石墨是元素碳最稳定的形式，由纯碳片组成，像一叠叠纸一样。被称为石墨烯的单个薄片优选平面几何形状，这是由于三角形碳原子的六边形蜂窝状排列构成了它们的二维网络。这种网络中的非六边形环形式的缺陷导致偏离平面性的扭曲。在这里，我们报告一个极端的例子，这种现象。采用分步化学法合成了一种26环C80H30纳米石墨烯，该石墨烯由五个七元环和一个五元环组成，嵌在六方晶格中，经分离、纯化和光谱表征。单晶X射线晶体学揭示了它严重扭曲的结构。一个独立的合成路线，这种新型的“纳米碳”的自由可溶性衍生物也报道。实验数据揭示了如此大的石墨烯亚基的性质如何受到多个奇元环缺陷的影响。
Graphite, the most stable form of elemental carbon, consists of pure carbon sheets stacked upon one another like reams of paper. Individual sheets, known as graphene, prefer planar geometries as a consequence of the hexagonal honeycomb-like arrangements of trigonal carbon atoms that comprise their two-dimensional networks. Defects in the form of non-hexagonal rings in such networks cause distortions away from planarity. Herein we report an extreme example of this phenomenon. A 26-ring C80H30 nanographene that incorporates five seven-membered rings and one five-membered ring embedded in a hexagonal lattice was synthesized by stepwise chemical methods, isolated, purified and fully characterized spectroscopically. Its grossly warped structure was revealed by single-crystal X-ray crystallography. An independent synthetic route to a freely soluble derivative of this new type of 'nanocarbon' is also reported. Experimental data reveal how the properties of such a large graphene subunit are affected by multiple odd-membered-ring defects.