Abstract:
Splitting the five and seven-membered rings of azulene and embedding them separately into a conjugated backbone provides azulene-like polycyclic aromatic hydrocarbons (PAHs), which are of great interest in quantum and material chemistry. However, the synthetic accessibility poses a significant challenge. In this study, we present the synthesis of a novel azulene-like PAH, Pery-57, which can be viewed as the integration of a perylene framework into the split azulene. The compact structure of Pery-57 displays several intriguing characteristics, including NIR II absorption at 1200 nm, a substantial dipole moment of 3.5 D, and head-to-tail alternating columnar packing. Furthermore, Pery-57 exhibits remarkable redox properties. The cationic radical Pery-57•+ readily captures a hydrogen atom. Variable-temperature NMR (VT-NMR) and variable-temperature EPR (VT-EPR) studies reveal that the dianion Pery-572- possesses an open-shell singlet ground state and demonstrates significant global anti-aromaticity. The dication Pery-572+ is also predicted to exhibit diradical character. Despite bearing three bulky substituents, Pery-57 displays p-type transport characteristics with a mobility of 0.03 cm2 V-1 s-1, attributed to its unique azulene-like structure. Overall, this work directs interest in azulene-like PAHs, a unique member of nonalternant PAHs showcasing exceptional properties and applications.
摘要:
分裂azulene的五元和七元环并将它们分别嵌入共轭主链中,提供了类azulene多环芳烃(PAHs),对量子化学和材料化学非常感兴趣。然而,合成的可及性构成了重大挑战。在这项研究中,我们介绍了一种新型的类甘菊环类PAH的合成,Pery-57,可以将其视为将perylene骨架整合到分裂的azulene中。Pery-57的紧凑结构表现出几个有趣的特点,包括1200nm的NIRII吸收,3.5D的大量偶极矩,头对尾交替柱状填料。此外,Pery-57具有显着的氧化还原特性。阳离子自由基Pery-57•+容易捕获氢原子。可变温度NMR(VT-NMR)和可变温度EPR(VT-EPR)研究表明,阴离子Pery-572-具有开壳单线态基态,并显示出明显的全球反芳香性。指示Pery-572+也被预测表现出双自由基特性。尽管带有三个庞大的取代基,Pery-57显示出p型传输特性,迁移率为0.03cm2V-1s-1,这归因于其独特的类azulene结构。总的来说,这项工作引起了人们对类似于azulene的PAHs的兴趣,非交替PAHs的独特成员,展示了卓越的性能和应用。