Pérez-Elvira Elena, Wu Fupeng, Hwang Jeong Ha, Ma Ji, Palomino-Ruiz Lucia, Canola Sofia, Barragán Ana, Lauwaet Koen, Gallego José M, Miranda Rodolfo, Perrin Mickael L, Écija David, Gallardo Aurelio, Borin Barin Gabriela, Feng Xinliang, Urgel José I
IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid, 28049, Spain.
Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany.
Angew Chem Int Ed Engl. 2025 Sep 8;64(37):e202506803. doi: 10.1002/anie.202506803. Epub 2025 Jul 25.
Structural, chemical, and extrinsic modifications of graphene-based nanostructures enable bandgap tuning, optoelectronics, spintronics, and quantum materials design. A well-known approach to modify their electronic properties involves introducing nonbenzenoid ring topologies in their ideal sp-hybridized hexagonal lattice, such as azulene or Stone-Wales (SW) defects. However, despite the unique structural and electronic characteristics that these nonalternant defects induce, their systematic incorporation in graphene-based nanostructures remains challenging. Here, we demonstrate the on-surface synthesis of one-dimensional SW-based polymers linked through cumulene bonds on the Au(111) surface via thermal and visible-light-induced reactions of a tailored molecular precursor. Scanning tunneling and noncontact atomic force microscopies reveal the nonplanar structure of SW-based units within the polymer chain, while the chemical structure of the polymer has been verified by Raman spectroscopy in combination with theoretical modeling. Additionally, scanning tunneling spectroscopy measurements show an experimental bandgap of 1.8 eV, which significantly differs from its isostructural cumulene-bridged bisanthene analogs. Our results highlight the critical role of SW defects in the structural and electronic properties of carbon-based conjugated polymers, advancing their design with prospects in next-generation optoelectronic devices.
基于石墨烯的纳米结构的结构、化学和外在修饰能够实现带隙调控、光电子学、自旋电子学以及量子材料设计。一种用于修饰其电子性质的知名方法是在其理想的sp杂化六边形晶格中引入非苯环拓扑结构，例如薁或斯通-威尔士（SW）缺陷。然而，尽管这些非交替缺陷会诱导出独特的结构和电子特性，但将它们系统地引入基于石墨烯的纳米结构中仍然具有挑战性。在此，我们展示了通过定制分子前驱体的热反应和可见光诱导反应，在Au(111)表面上通过累积双键连接的一维基于SW的聚合物的表面合成。扫描隧道显微镜和非接触原子力显微镜揭示了聚合物链中基于SW的单元的非平面结构，而聚合物的化学结构已通过拉曼光谱结合理论建模得到验证。此外，扫描隧道光谱测量显示实验带隙为1.8 eV，这与其同构的累积双键桥连双薁类似物有显著差异。我们的结果突出了SW缺陷在碳基共轭聚合物的结构和电子性质中的关键作用，推动了它们在下一代光电器件中的设计应用前景。
