Synthesis of a Möbius carbon nanobelt
Synthesis of a Möbius carbon nanobelt
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DOI：
10.1038/s44160-022-00075-8
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发表时间：
2022-07-01
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影响因子：
--
通讯作者：
Itami, Kenichiro
中科院分区：
文献类型：
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作者：
Segawa, Yasutomo;Watanabe, Tsugunori;Itami, Kenichiro
创建拓扑碳纳米结构的技术极大地推进了合成有机化学和材料科学。尽管已经构建了具有带拓扑结构的简单分子纳米碳，但由于其高内在应变，尚未合成具有扭曲的类似碳纳米带，更具体地说，莫比乌斯碳纳米带（MCNB）。在这里，我们报告了 MCNB 的合成、分离和表征。应变能的计算表明大型 MCNB 是可以合成的。设计具有奇数个重复单元的大环前体，通过 Z 选择性 Wittig 反应和镍介导的分子内自偶联反应成功合成路线，经过 14 个步骤得到 (25,25)MCNB。核磁共振波谱和理论计算表明，莫比乌斯带的扭曲部分在溶液中的 MCNB 分子周围快速移动。源自莫比乌斯结构的拓扑手性通过手性高效液相色谱分离和圆二色光谱法得到了实验证实。拓扑碳纳米结构的创建策略极大地推进了合成有机化学和材料科学。现在，报道了莫比乌斯碳纳米带的合成，这是一种带状芳香烃扭曲的分子。
Technologies for the creation of topological carbon nanostructures have greatly advanced synthetic organic chemistry and materials science. Although simple molecular nanocarbons with a belt topology have been constructed, analogous carbon nanobelts with a twist-more specifically, Mobius carbon nanobelts (MCNBs)-have not yet been synthesized owing to their high intrinsic strain. Here we report the synthesis, isolation and characterization of a MCNB. Calculations of strain energies suggest that large MCNBs are synthetically accessible. Designing a macrocyclic precursor with an odd number of repeat units led to a successful synthetic route via Z-selective Wittig reactions and nickel-mediated intramolecular homocoupling reactions, which yielded (25,25)MCNB over 14 steps. NMR spectroscopy and theoretical calculations reveal that the twist moiety of the Mobius band moves quickly around the MCNB molecule in solution. The topological chirality that originates from the Mobius structure was confirmed experimentally using chiral HPLC separation and circular dichroism spectroscopy.Strategies for the creation of topological carbon nanostructures have greatly advanced synthetic organic chemistry and materials science. Now, the synthesis of a Mobius carbon nanobelt, a molecule with a twist on belt-shaped aromatic hydrocarbons, is reported.