Benzenoid Polycyclic Hydrocarbons with an Open–Shell Biradical Ground State

This Focus Review describes the recent progress, from both theoretical and experimental perspectives, on four types of benzenoid polycyclic hydrocarbons with an open–shell biradical ground state: 1) acenes, 2) periacenes and anthenes, 3) zethrenes, and 4) extended p‐quinodimethane derivatives. These interesting molecules have provided excellent platforms to investigate the electronic structures of nanographenes and represent promising candidates for the next generation of molecule‐based materials in the field of electronics, spintronics, and non‐linear optics. The focus of this article will be put on the structural significance, the physical properties relevant to the open–shell electronic configurations, and potential applications.