Li Chenglong, Zhang Chen, Li Pengfei, Jia Yawei, Duan Jiaxian, Liu Meiyan, Zhang Niu, Chen Pangkuan
Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China.
Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les matériaux, UMR CNRS 5254, Université de Pau et des Pays de l'Adour, Avenue de l' Université, 64000, Pau, France.
Angew Chem Int Ed Engl. 2023 Apr 24;62(18):e202302019. doi: 10.1002/anie.202302019. Epub 2023 Mar 24.
We herein present the synthetic approach to a new antiaromatic double aza[7]helicene C that features NN-embedded polycyclic aromatic hydrocarbons (PAHs). This heteroatom-doped helicene showed a rarely obtained long-wavelength emission and far-red circularly polarized luminescence (CPL) in the solid state. These optical and chiroptical properties could be ascribed to both the NN-PAH core structure and the further extension through angular ring fusions. Such a unique electronic structure also culminated in facile chemical oxidations of neutral C to the positively charged chiral radical (C⋅ ) and dication species (C ). Interestingly, DFT computations revealed that the pyridazine central core showed an antiaromaticity-to-aromaticity switching, in contrast to the inversed transition for the helical periphery in cationic states. The reported approaches are anticipated to lead to the development of further redox-active chiral systems for potential applications in chiroptoelectronics, spintronics as well as fluorescent bioimaging.
我们在此展示了一种合成新型反芳香性双氮杂[7]螺旋烯C的方法，该螺旋烯具有嵌入NN的多环芳烃（PAH）。这种杂原子掺杂的螺旋烯在固态下表现出罕见的长波长发射和远红光圆偏振发光（CPL）。这些光学和手性光学性质可归因于NN-PAH核心结构以及通过角环稠合的进一步扩展。这种独特的电子结构还导致中性C易于化学氧化为带正电荷的手性自由基（C⋅ ）和双阳离子物种（C ）。有趣的是，密度泛函理论（DFT）计算表明，哒嗪中心核显示出反芳香性到芳香性的转变，这与阳离子态下螺旋外围的反向转变形成对比。预计所报道的方法将导致进一步开发用于手性光电子学、自旋电子学以及荧光生物成像潜在应用的氧化还原活性手性系统。
