Perylene with Split‐Azulene Embedding

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.