We report the synthesis of a longitudinally helical molecular nanocarbon, hexabenzoheptacene (HBH), along with its dimethylated derivative (HBH‐Me), which are composed of six benzene rings periodically benzannulated to both zigzag edges of a heptacene core. This benzannulation pattern endows the resulting nanocarbons with a helical heptacene core and local aromaticity, imparting enhanced solubility and stability to the system. The chiral HBH‐Me adopts a more highly twisted conformation with an end‐to‐end twist angle of 95°, enabling the separation of the enantiomers. Both HBH and HBH‐Me can be facilely oxidized into their corresponding dications, which exhibit enhanced planarity and aromaticity upon loss of electrons. Notably, both longitudinally helical nanocarbons readily promote solid state packing into two‐dimensional (2D) arrangement. Single‐crystal microbelts of HBH‐Me show hole mobility up to 0.62 cm2 V‐1 s‐1, illustrating the promising potential of these longitudinally helical molecules for organic electronic devices.

中文翻译：

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六苯并庚烯：具有局部芳香性和增强稳定性的纵向多螺旋烯纳米碳


我们报道了纵向螺旋分子纳米碳六苯并庚苯（HBH）及其二甲基化衍生物（HBH-Me）的合成，它们由六个周期性苯环连接到庚苯核心的两个锯齿形边缘的苯环组成。这种苯环化模式赋予所得纳米碳螺旋庚苯核心和局部芳香性，从而增强了系统的溶解度和稳定性。手性HBH-Me采用更高度扭曲的构象，端到端扭曲角为95°，能够实现对映体的分离。 HBH 和 HBH-Me 都可以很容易地氧化成相应的双阳离子，在失去电子时表现出增强的平面性和芳香性。值得注意的是，两种纵向螺旋纳米碳都很容易促进固态堆积成二维（2D）排列。 HBH-Me 的单晶微带显示出高达 0.62 cm2 V-1 s-1 的空穴迁移率，说明了这些纵向螺旋分子在有机电子器件中的巨大潜力。