Borrisov Boris, Beneventi Giovanni M, Fu Yubin, Qiu Zhen-Lin, Komber Hartmut, Deng Qing-Song, Greißel Phillip M, Cadranel Alejandro, Guldi Dirk M, Ma Ji, Feng Xinliang
Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany.
Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
J Am Chem Soc. 2024 Oct 9;146(40):27335-27344. doi: 10.1021/jacs.4c09224. Epub 2024 Sep 27.
The construction of multiple heptagonal rings in nanographene is the key step for obtaining exotic carbon nanostructures with a negative curvature and intriguing properties. Herein, a novel saddle-shaped nanographene () with four embedded heptagons is synthesized via a highly efficient one-shot Scholl reaction from a predesigned oligophenylene precursor. Notably, a quadruple [6]helicene intermediate was also obtained and isolated by controlling the Scholl reaction conditions. Interestingly, the single crystal structures of display a saddle geometry induced by the four embedded heptagons, resulting in a deep curvature with a width of 16.5 Å and a depth of 8.0 Å. Theoretical calculations at the molecular level suggest a weak antiaromatic character of the heptagons in . Remarkably, compound exhibits dual fluorescence from S and S. The deep-saddle-shaped geometry in defines host-guest interactions with fullerenes, which were explored in titration experiments and by theoretical methods. The resulting are stable and are subject to an electron transfer from photoexcited to . Our current study underscores the influence of heptagon rings on the photophysical, self-assembly, and electron-donating properties of NGs.
在纳米石墨烯中构建多个七元环是获得具有负曲率和有趣性质的奇异碳纳米结构的关键步骤。在此，通过从预先设计的低聚苯撑前体进行高效的一步法肖尔反应，合成了一种具有四个嵌入七元环的新型鞍形纳米石墨烯（）。值得注意的是，通过控制肖尔反应条件，还获得并分离出了一种四重[6]螺旋烯中间体。有趣的是，的单晶结构显示出由四个嵌入七元环诱导的鞍形几何形状，导致深度为16.5 Å、宽度为8.0 Å的深曲率。分子水平的理论计算表明中七元环具有较弱的反芳香性。值得注意的是，化合物从S和S表现出双重荧光。中的深鞍形几何形状定义了与富勒烯的主客体相互作用，通过滴定实验和理论方法对其进行了探索。所得的是稳定的，并且存在从光激发的到的电子转移。我们目前的研究强调了七元环对纳米石墨烯的光物理、自组装和供电子性质的影响。
