Obermann Sebastian, Zheng Wenhao, Melidonie Jason, Böckmann Steffen, Osella Silvio, Arisnabarreta Nicolás, Guerrero-León L Andrés, Hennersdorf Felix, Beljonne David, Weigand Jan J, Bonn Mischa, De Feyter Steven, Hansen Michael Ryan, Wang Hai I, Ma Ji, Feng Xinliang
Center for Advancing Electronics Dresden (cfaed), Faculty of Chemistry and Food Chemistry, Technische Universität Dresden D-01069 Dresden Germany
Max-Planck-Institute for Polymer Research D-55128 Mainz Germany.
Chem Sci. 2023 Jul 27;14(32):8607-8614. doi: 10.1039/d3sc02824k. eCollection 2023 Aug 16.
Precise synthesis of graphene nanoribbons (GNRs) is of great interest to chemists and materials scientists because of their unique opto-electronic properties and potential applications in carbon-based nanoelectronics and spintronics. In addition to the tunable edge structure and width, introducing curvature in GNRs is a powerful structural feature for their chemi-physical property modification. Here, we report an efficient solution synthesis of the first pyrene-based GNR (PyGNR) with curved geometry one-pot K-region oxidation and Scholl cyclization of its corresponding well-soluble tetrahydropyrene-based polyphenylene precursor. The efficient AB-type Suzuki polymerization and subsequent Scholl reaction furnishes up to ∼35 nm long curved GNRs bearing cove- and armchair-edges. The construction of model compound 1, as a cutout of PyGNR, from a tetrahydropyrene-based oligophenylene precursor proves the concept and efficiency of the one-pot K-region oxidation and Scholl cyclization, which is clearly revealed by single crystal X-ray diffraction analysis. The structure and optical properties of PyGNR are investigated by Raman, FT-IR, solid-state NMR, STM and UV-Vis analysis with the support of DFT calculations. PyGNR exhibits a narrow optical bandgap of ∼1.4 eV derived from a Tauc plot, qualifying as a low-bandgap GNR. Moreover, THz spectroscopy on PyGNR estimates its macroscopic charge mobility as ∼3.6 cm V s, outperforming several other curved GNRs reported conventional Scholl reaction.
石墨烯纳米带（GNRs）的精确合成引起了化学家和材料科学家的极大兴趣，因为它们具有独特的光电特性以及在碳基纳米电子学和自旋电子学中的潜在应用。除了可调节的边缘结构和宽度外，在GNRs中引入曲率是一种强大的结构特征，可用于修饰其化学物理性质。在此，我们报告了一种高效的溶液合成方法，用于合成首例具有弯曲几何形状的芘基GNR（PyGNR）——通过其相应的可良好溶解的四氢芘基聚苯撑前体的一锅法K区域氧化和肖尔环化反应。高效的AB型铃木聚合反应及随后的肖尔反应可制备出长达约35 nm的带有凹面边缘和扶手椅边缘的弯曲GNRs。由四氢芘基低聚苯撑前体构建模型化合物1作为PyGNR的一个片段，证明了一锅法K区域氧化和肖尔环化反应的概念和效率，单晶X射线衍射分析清楚地揭示了这一点。在密度泛函理论计算的支持下，通过拉曼光谱、傅里叶变换红外光谱、固态核磁共振、扫描隧道显微镜和紫外可见光谱分析对PyGNR的结构和光学性质进行了研究。PyGNR从Tauc图得出的光学带隙约为1.4 eV，较窄，属于低带隙GNR。此外，对PyGNR的太赫兹光谱分析估计其宏观电荷迁移率约为3.6 cm² V⁻¹ s⁻¹，优于其他一些报道的通过传统肖尔反应制备的弯曲GNRs。
