A kinetically blocked 1,14:11,12-dibenzopentacene : a persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon

• Main Authors: Li, Yuan, Huang, Kuo-Wei, Sun, Zhe, Webster, Richard David, Zeng, Zebing, Zeng, Wangdong, Chi, Chunyan, Ko, Furukawa, Wu, Jishan
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2018
• Subjects: DRNTU::Science::Chemistry; Benzenoid hydrocarbons; Polycyclic Hydrocarbon
• Online Access: https://hdl.handle.net/10356/87954; http://hdl.handle.net/10220/45702
• Institution: Nanyang Technological University

The synthesis of high-spin polycyclic hydrocarbons is very challenging due to their extremely high reactivity. Herein, we report the synthesis and characterization of a kinetically blocked 1,14:11,12-dibenzopentacene, DP-Mes, which represents a rare persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon. In contrast to its structural isomer 1,14:7,8-dibenzopentacene (heptazethrene) with a singlet biradical ground state, DP-Mes is a triplet diradical as confirmed by ESR and ESTN measurements and density functional theory calculations. DP-Mes also displays intermolecular antiferromagnetic spin interactions in solution at low temperature.