All-Benzene Carbon Nanocages: Size-Selective Synthesis, Photophysical Properties, and Crystal Structure
All-Benzene Carbon Nanocages: Size-Selective Synthesis, Photophysical Properties, and Crystal Structure
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DOI：
10.1021/ja509880v
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发表时间：
2014-11-19
影响因子：
15
通讯作者：
Itami, Kenichiro
中科院分区：
文献类型：
--
作者：
Matsui, Katsuma;Segawa, Yasutomo;Itami, Kenichiro
介绍了一系列完全由苯环组成的碳纳米笼的设计和合成。碳纳米笼是极具吸引力的分子，不仅因为它们代表了支化碳纳米管的连接单元结构，而且还因为它们作为独特的光电PI共轭材料和客体包裹主体的潜在用途。合成了3种尺寸的应变、共轭[n.n.n]碳纳米笼(1，n=4；2，n=5；3，n=6)，具有良好的尺寸选择性。将含环己烷单元和1，3，5-三取代苯基单元组装成最小应变的双环前驱体，并通过酸催化芳构化成功地转化为相应的碳纳米笼。1的X射线结晶学证实了笼状结构，笼状分子内部有一个近似球形的空洞。目前的研究揭示了碳纳米笼的独特性质，包括应变能、依赖于尺寸的吸收和荧光，以及1-3的电子特征的独特的尺寸依赖关系。
The design and synthesis of a series of carbon nanocages consisting solely of benzene rings are described. Carbon nanocages are appealing molecules not only because they represent junction unit structures of branched carbon nanotubes, but also because of their potential utilities as unique optoelectronic pi-conjugated materials and guest-encapsulating hosts. Three sizes of strained, conjugated [n.n.n]carbon nanocages (1, n = 4; 2, n = 5; 3, n = 6) were synthesized with perfect size-selectivity. Cyclohexane-containing units and 1,3,5-trisubstituted benzene-containing units were assembled to yield the minimally strained bicyclic precursors, which were successfully converted into the corresponding carbon nanocages via acid-mediated aromatization. X-ray crystallography of 1 confirmed the cage-shaped structure with an approximately spherical void inside the cage molecule. The present studies revealed the unique properties of carbon nanocages, including strain energies, size-dependent absorption and fluorescence, as well as unique size-dependency for the electronic features of 1-3.