Toward Stable Superbenzoquinone Diradicaloids

Guangwu Li; Hoa Phan; Tun Seng Herng; Tullimilli Y Gopalakrishna; Chunchen Liu; Wangdong Zeng; Jun Ding; Jishan Wu

doi:10.1002/anie.201700441

Toward Stable Superbenzoquinone Diradicaloids

Angew Chem Int Ed Engl. 2017 Apr 24;56(18):5012-5016. doi: 10.1002/anie.201700441. Epub 2017 Mar 30.

Authors

Guangwu Li¹, Hoa Phan¹, Tun Seng Herng², Tullimilli Y Gopalakrishna¹, Chunchen Liu¹, Wangdong Zeng¹, Jun Ding², Jishan Wu¹

Affiliations

¹ Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore.
² Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore, Singapore.

PMID: 28371126
DOI: 10.1002/anie.201700441

Abstract

Superbenzoquinone (SBQ) is a quinone derived from a classic polycyclic aromatic hydrocarbon (PAH), hexa-peri-hexabenzocoronene (so-called "superbenzene"), and is a challenging synthetic target. Herein we report the successful synthesis and characterization of its derivatives. We reveal that the high reactivity of SBQ is due to its intrinsic open-shell diradical character. Thus, two kinetically blocked SBQs, SBQ-Me and SBQ-Ph, were prepared by different synthetic strategies. 4-tert-Butylphenyl-substituted SBQ-Ph demonstrated good stability and could be isolated in crystalline form. Both compounds have an open-shell singlet ground state and show thermally populated paramagnetic activity. Our studies provide effective strategies toward stable quinone-based diradicaloids.

Keywords: diradicaloids; dyes/pigments; near-infrared dyes; polycyclic aromatic hydrocarbons; quinones.

Publication types

Research Support, Non-U.S. Gov't