Super-heptazethrene

• Published in: Angewandte Chemie International Edition Vol. 55; no. 30; pp. 8615 - 8619
• Main Authors: Zeng, Wangdong, Sun, Zhe, Herng, Tun Seng, Gonçalves, Théo P., Gopalakrishna, Tullimilli Y., Huang, Kuo-Wei, Ding, Jun, Wu, Jishan
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 18.07.2016; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical properties; Physical Sciences; polycyclic hydrocarbons; quinoids; radicals; Science & Technology; synthetic methods; zethrene; EDGE STATE; GRAPHENE NANORIBBONS; POLYCYCLIC AROMATIC-HYDROCARBON; radicals; zethrene; OPEN-SHELL; polycyclic hydrocarbons; EXTENDED P-QUINODIMETHANES; SINGLET; MOLECULES; KEKULE STRUCTURES; BIRADICAL GROUND-STATE; CHARACTER; quinoids; synthetic methods
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201602997

The challenging synthesis of a laterally extended heptazethrene molecule, the super‐heptazethrene derivative SHZ‐CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ‐CF3 exhibits an open‐shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo‐terrylene SHZ‐2H was also obtained during the synthesis. This study provides a new synthetic method to access large‐size quinoidal polycyclic hydrocarbons with unique physical properties. Expanding horizons: The complex polycyclic hydrocarbon super‐heptazethrene was synthesized using a strategy involving a selective multiple intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Super‐heptazethrene displayed a much larger diradical character (y0) than heptazethrene.