Gao Yuan, Hua Xinqiang, Jiang Wei, Sun Chun-Lin, Yuan Chengshan, Liu Zitong, Zhang Hao-Li, Shao Xiangfeng
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Tianshui Southern Road 222, Lanzhou, 730000, Gansu, Province, China.
Angew Chem Int Ed Engl. 2022 Nov 2;61(44):e202210924. doi: 10.1002/anie.202210924. Epub 2022 Oct 5.
Graphene nanoribbons (GNRs) are promising in organic optoelectronic materials, and their properties largely depend on the size, edge, and conformation. Herein, the fully armchair-edged GNRs (AGNRs) with lengths up to 2.65 nm by using a Cu-catalyzed deoxygenative coupling as a key step. The resulting AGNRs (2HBT, 3HBT, and 4HBT) possess highly twisted π-scaffolds, and the torsion angles between the adjacent triphenylene moieties are larger than 32°, as proved by crystallographic analyses. Theoretical and spectroscopic studies show that the butoxy groups endow AGNRs with electron-rich features, the extension of the π-system from 2HBT to 4HBT reinforces S →S excitation, and the distortion of the π-scaffold enhances the fluorescence quantum yield (Φ ). In particular, 4HBT has the lowest oxidation potential (E =0.55 V vs. SCE) and displays red fluorescence with a Φ value of 81 %.
石墨烯纳米带（GNRs）在有机光电子材料领域颇具潜力，其性质很大程度上取决于尺寸、边缘和构象。在此，通过以铜催化的脱氧偶联作为关键步骤，制备出了长度达2.65 nm的全扶手椅边缘GNRs（AGNRs）。晶体学分析表明，所得的AGNRs（2HBT、3HBT和4HBT）具有高度扭曲的π骨架，相邻三亚苯基部分之间的扭转角大于32°。理论和光谱研究表明，丁氧基赋予AGNRs富电子特性，π体系从2HBT到4HBT的延伸增强了S→S激发，并且π骨架的扭曲提高了荧光量子产率（Φ）。特别是，4HBT具有最低的氧化电位（E =0.55 V 对SCE），并呈现出Φ值为81%的红色荧光。
