Hexa-peri-hexabenzo[7]helicene: Homogeneously π-Extended Helicene as a Primary Substructure of Helically Twisted Chiral Graphenes,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Hexa-peri-hexabenzo[7]helicene: Homogeneously π-Extended Helicene as a Primary Substructure of Helically Twisted Chiral Graphenes
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2018-03-19 , DOI: 10.1021/jacs.7b13412
Yusuke Nakakuki ₁ , Takashi Hirose ₁ , Hikaru Sotome ₂ , Hiroshi Miyasaka ₂ , Kenji Matsuda ₁

Affiliation

Helically twisted graphenes can be considered as a promising candidate for the nanometer-sized molecular inductors in molecular electronics and molecular spring materials in nanomechanics. Here, we report the synthesis of hexa- peri-hexabenzo[7]helicene, which represents a primary substructure of the helical graphenes. The helically twisted polycyclic aromatic hydrocarbon was synthesized by a tetrasubstituted alkene formation using McMurry coupling followed by stepwise photocyclodehydrogenation and aromatization reactions. The π-extended helicoid structure with a noticeable intramolecular π-π interaction was unambiguously determined by X-ray crystallography. The primary helical nanographene molecule has a small HOMO-LUMO band gap evidenced by the absorption edge that appeared at ca. 800 nm, which exhibits an excellent chiroptical property with a dissymmetry factor of circular dichroism of | gCD| = 0.016 at 680 nm. The femtosecond transient absorption spectroscopy revealed the ultrafast excited-state dynamics of the helical nanographene molecule, with a lifetime of only few picoseconds in the lowest-energy excited (S1) state.

中文翻译：

Hexa-peri-hexabenzo[7] helicene：作为螺旋扭曲手性石墨烯的主要亚结构的均质 π-扩展的 Helicene

螺旋扭曲的石墨烯可以被认为是分子电子学中的纳米级分子电感器和纳米力学中的分子弹簧材料的有希望的候选者。在这里，我们报告了六周六苯并 [7] 螺旋烯的合成，它代表了螺旋石墨烯的主要亚结构。螺旋扭曲的多环芳烃是通过使用 McMurry 偶联形成四取代烯烃，然后逐步光环脱氢和芳构化反应合成的。X 射线晶体学明确确定了具有显着分子内 π-π 相互作用的 π 延伸螺旋结构。主要的螺旋纳米石墨烯分子具有小的 HOMO-LUMO 带隙，这由出现在约 800纳米，其圆二色性的不对称因子为 | 唱片| = 0.016 在 680 nm。飞秒瞬态吸收光谱揭示了螺旋纳米石墨烯分子的超快激发态动力学，在最低能量激发 (S1) 状态下的寿命仅为几皮秒。

更新日期：2018-03-19

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11