近日，中国科学技术大学王冰团队实现了通过五元环的区域选择性环化，在Clar的杯状石墨烯纳米带中定制近费米能级拓扑平带。相关论文发表在2025年9月11日出版的《美国化学会志》上。

通过金属表面催化的C-C键形成进行表面合成，为设计具有原子精度的石墨纳米材料提供了独特的优势。遵循这种方法，在石墨烯纳米带（GNR）中植入非平凡的拓扑和平带结构已成为一种引人注目的追求，通过拓扑状态和强相关性的相互作用，成为实现物质奇异量子相的平台。然而，对这些有趣性质的探索在很大程度上受到能够在GNR中产生拓扑平带的有限已知表面反应的限制。

在这项工作中，研究组促进了隐藏的非凯库伦纳米石墨烯的分子间氧化偶联，以在Au（111）表面构建拓扑平带GNR和GNR异质结。利用Clar的杯状物作为概念证明，研究组证明了具有高区域选择性的重复分子间环脱氢形成五边形嵌入的GNR。Clar杯状物中零模的耦合产生了扩展的电子态，它们之间有明显的节点，这是由固有的拓扑挫折引起的，从而产生了接近费米能级的拓扑平带和拓扑保护的末端态。

研究组使用扫描隧道显微镜和非接触式原子力显微镜获得的原子分辨测量结果，辅以密度泛函理论和紧束缚模型计算，说明了表面反应级联和设计产品的电子特性。这些发现为低维碳基量子材料的表面构建开辟了重大机遇。

附：英文原文

Title: Tailoring Near Fermi-Level Topological Flatbands in Clar’s Goblet Graphene Nanoribbons through Regioselective Cyclization of Five-Membered Rings

Author: Ruoting Yin, Xinyong Meng, Xin-Jing Zhao, Jianing Wang, Xiaoqing Wang, Qi Chen, Jie Meng, Zhengya Wang, Yifan Liang, Yuan-Zhi Tan, Bin Li, Wei Hu, Qunxiang Li, Shijing Tan, Chuanxu Ma, Jinlong Yang, Bing Wang

Issue&Volume: September 11, 2025

Abstract: On-surface synthesis via metal-surface-catalyzed C–C bond formation presents unique advantages for the design of graphitic nanomaterials with atomic precision. Following this approach, the coimplantation of nontrivial topology and flatband structures in graphene nanoribbons (GNRs) has emerged as a compelling pursuit, serving as platforms for realizing exotic quantum phases of matter through the interplay of topological states and strong correlations. However, the exploration of these intriguing properties has been largely constrained by the limited known on-surface reactions capable of creating topological flatbands in GNRs. In this work, we promote the intermolecular oxidative coupling of concealed non-Kekuléan nanographenes to construct topological flatband GNRs and GNR heterojunctions on the Au(111) surface. Utilizing Clar’s goblet as a proof of concept, we demonstrate repetitive intermolecular cyclodehydrogenation with high regioselectivity to form pentagon-embedded GNRs. The coupling of the zero modes in Clar’s goblets generates extended electronic states with evident nodes between them, arising from inherent topological frustration, thus resulting in topological flatbands close to the Fermi level and topologically protected end states. Our atomically resolved measurements obtained using scanning tunneling microscopy and noncontact atomic force microscopy, complemented by density functional theory and tight-binding model calculations, illustrate the on-surface reaction cascade and the electronic properties of the designed products. These findings open significant opportunities for the on-surface construction of low-dimensional carbon-based quantum materials.

DOI: 10.1021/jacs.5c03736

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c03736