英国牛津大学Gross, Leo团队报道了双反芳香碳同素异形体的表面合成。相关研究成果于2023年10月25日发表在《自然》。

石墨烯、碳纳米管和富勒烯等合成碳同素异形体彻底改变了材料科学，并带来了新技术。研究人员已经讨论了许多假设的碳同素异形体，但很少进行实验研究。最近，动态共价化学和表面合成等非常规合成策略已被用于创造新形式的碳，包括γ-石墨烯、富勒烯聚合物、联苯网络和环碳。环[N]碳是由N个碳原子1组成的分子环；迄今为止已经报道的三种（N=10，14和18）是双芳香性的，这引发了一个问题：是否有可能制备双反芳族版本。

该文中，研究人员报道了通过使用尖端诱导的表面化学合成和表征反芳族碳同素异形体环[16]碳。除了来自原子力显微镜的结构信息外，研究人员还通过扫描隧道显微镜记录轨道密度图来探测其电子结构。环[16]碳中键长变化的观察证实了其双重反芳香性，与理论一致。C16的简单结构使其成为研究芳香性极限的有趣的模型系统，其高反应性使其成为新型碳同素异形体的有前途的前体。

附：英文原文

Title: On-surface synthesis of a doubly anti-aromatic carbon allotrope

Author: Gao, Yueze, Albrecht, Florian, Ronevi, Igor, Ettedgui, Isaac, Kumar, Paramveer, Scriven, Lorel M., Christensen, Kirsten E., Mishra, Shantanu, Righetti, Luca, Rossmannek, Max, Tavernelli, Ivano, Anderson, Harry L., Gross, Leo

Issue&Volume: 2023-10-25

Abstract: Synthetic carbon allotropes such as graphene1, carbon nanotubes2 and fullerenes3 have revolutionized materials science and led to new technologies. Many hypothetical carbon allotropes have been discussed4, but few have been studied experimentally. Recently, unconventional synthetic strategies such as dynamic covalent chemistry5 and on-surface synthesis6 have been used to create new forms of carbon, including γ-graphyne7, fullerene polymers8, biphenylene networks9 and cyclocarbons10,11. Cyclo[N]carbons are molecular rings consisting of N carbon atoms12,13; the three that have been reported to date (N=10, 14 and 18)10,11 are doubly aromatic, which prompts the question: is it possible to prepare doubly anti-aromatic versions Here we report the synthesis and characterization of an anti-aromatic carbon allotrope, cyclo[16]carbon, by using tip-induced on-surface chemistry6. In addition to structural information from atomic force microscopy, we probed its electronic structure by recording orbital density maps14 with scanning tunnelling microscopy. The observation of bond-length alternation in cyclo[16]carbon confirms its double anti-aromaticity, in concordance with theory. The simple structure of C16 renders it an interesting model system for studying the limits of aromaticity, and its high reactivity makes it a promising precursor to novel carbon allotropes15.

DOI: 10.1038/s41586-023-06566-8

Source: https://www.nature.com/articles/s41586-023-06566-8