Sun Luye, Zheng Wei, Kang Faming, Gao Wenze, Wang Tongde, Gao Guohua, Xu Wei
Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China.
Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
Nat Commun. 2024 Sep 3;15(1):7649. doi: 10.1038/s41467-024-52115-w.
Cyclo[n]carbons have recently attracted significant attention owing to their geometric and electronic structures remaining largely unexplored in the condensed phase. In this work, we focus on two anti-aromatic cyclocarbons, namely C and C. By designing two fully halogenated molecular precursors both including 4-numbered rings, we further extend the on-surface retro-Bergman ring-opening reaction, and successfully produce C and C. The polyynic structures of C and C are unambiguously revealed by bond-resolved atomic force microscopy. More importantly, subtly positioning the C molecule into an atomic fence formed by Cl clusters allows us to experimentally probe its frontier molecular orbitals, yielding a transport gap of 3.8 eV measured from scanning tunneling spectroscopy. Our work may advance the field by easier synthesis of a series of cyclocarbons via on-surface retro-Bergman ring-opening strategy.
环[n]碳由于其在凝聚相中的几何和电子结构在很大程度上尚未被探索，最近引起了广泛关注。在这项工作中，我们聚焦于两种反芳香性环碳，即C和C。通过设计两种均包含四元环的全卤代分子前驱体，我们进一步拓展了表面逆伯格曼开环反应，并成功制备出了C和C。通过键分辨原子力显微镜明确揭示了C和C的多炔结构。更重要的是，将C分子巧妙地置于由Cl簇形成的原子围栏中，使我们能够通过实验探测其前沿分子轨道，从扫描隧道光谱测得的传输能隙为3.8 eV。我们的工作可能通过表面逆伯格曼开环策略更简便地合成一系列环碳来推动该领域的发展。
