Fujise Kei, Tsurumaki Eiji, Wakamatsu Kan, Toyota Shinji
Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan.
Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama, 700-0005, Japan.
Chemistry. 2021 Mar 8;27(14):4548-4552. doi: 10.1002/chem.202004720. Epub 2021 Jan 15.
Polycyclic aromatic compounds consisting of four or five fused anthracene units were synthesized by PtCl -catalyzed cycloisomerization as novel long expanded helicenes. These compounds have helical structures with significant stacking of the terminal anthracene moieties at 0.33 nm interlayer distance. In the UV-vis and fluorescence spectra, the absorption and emission bands were red-shifted as the number of fused anthracene units was increased. The characteristic broad and long-lived emission bands of the long analogues are explained by the excimer-like stabilization of the excited state. These photophysical data as well as their cyclic voltammetric data are discussed on the basis of the π-conjugation and interlayer π⋅⋅⋅π interactions in the molecular structures and the molecular orbitals. The barrier and mechanism of helical inversion are also reported.
由四个或五个稠合蒽单元组成的多环芳族化合物通过PtCl催化的环异构化反应合成，作为新型的长扩展螺旋烯。这些化合物具有螺旋结构，末端蒽部分在0.33 nm的层间距离处有显著堆积。在紫外可见光谱和荧光光谱中，随着稠合蒽单元数量的增加，吸收和发射带发生红移。长类似物的特征宽且长寿命发射带由激发态的准分子样稳定化来解释。基于分子结构和分子轨道中的π共轭和层间π⋅⋅⋅π相互作用，讨论了这些光物理数据及其循环伏安数据。还报道了螺旋反转的势垒和机理。
