Nishiuchi Tomohiko, Ito Ryuoh, Takada Aya, Yasuda Yuri, Nagata Takaya, Stratmann Erik, Kubo Takashi
Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan.
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Chem Asian J. 2019 May 15;14(10):1830-1836. doi: 10.1002/asia.201801806. Epub 2019 Jan 28.
Anthracene-attached tricyclic aromatic hydrocarbon radicals having different central polygons, Ant-5, Ant-6, and Ant-7, were synthesized to evaluate the role of an anthracene substituent group in the stability and reactivity of tricyclic aromatic hydrocarbon radicals. The bulky anthryl group effectively protects a carbon atom with high spin density, resulting in high persistence of the radicals. On the other hand, the combination of the anthryl group and the tricyclic aromatic scaffold makes the molecular structure drastically change from a twisted form to a folded form and an unpaired electron moves into the anthryl moiety, eventually affording a tail-to-tail σ-dimer.
合成了具有不同中心多边形的蒽连接的三环芳烃自由基Ant-5、Ant-6和Ant-7，以评估蒽取代基在三环芳烃自由基的稳定性和反应性中的作用。庞大的蒽基有效地保护了具有高自旋密度的碳原子，导致自由基具有高持久性。另一方面，蒽基与三环芳烃骨架的结合使分子结构从扭曲形式急剧转变为折叠形式，并且未成对电子移入蒽部分，最终得到尾对尾的σ-二聚体。
