On-Surface Synthesis of Non-Benzenoid Nanographenes by Oxidative Ring-Closure and Ring-Rearrangement Reactions
Lohr TG, Urgel J, Eimre K, Liu J, Di Giovannantonio M, Mishra S, Berger R, Ruffieux P, Pignedoli CA, Fasel R, Feng X (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 142
Pages Range: 13565-13572
Journal Issue: 31
DOI: 10.1021/jacs.0c05668
Abstract
Nanographenes (NGs) have gained increasing attention due to their immense potential as tailor-made organic materials for nanoelectronics and spintronics. They exhibit a rich spectrum of physicochemical properties that can be tuned by controlling the size or the edge structure or by introducing structural defects in the honeycomb lattice. Here, we report the design and on-surface synthesis of NGs containing several odd-membered polycycles induced by a thermal procedure on Au(111). Our scanning tunneling microscopy, noncontact atomic force microscopy, and scanning tunneling spectroscopy measurements, complemented by computational investigations, describe the formation of two nonbenzenoid NGs (2A,B) containing four embedded azulene units in the polycyclic framework, via on-surface oxidative ring-closure reactions. Interestingly, we observe surface-catalyzed skeletal ring rearrangement reactions in the NGs, which lead to the formation of additional heptagonal rings as well as pentalene and as-indacene units in 2A,B, respectively. 2A,B on Au(111) both exhibit narrow experimental frontier electronic gaps of 0.96 and 0.85 eV, respectively, and Fermi level pinning of their HOMOs together with considerable electron transfer to the substrate. Ab initio calculations estimate moderate open-shell biradical characters for the NGs in the gas phase.
Involved external institutions
Technische Universität Dresden
Germany (DE)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
University of Hong Kong (HKU) / 香港大學
Hong Kong (HK)
Germany (DE)
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology
Switzerland (CH)
University of Hong Kong (HKU) / 香港大學
Hong Kong (HK)
How to cite
APA:
Lohr, T.G., Urgel, J., Eimre, K., Liu, J., Di Giovannantonio, M., Mishra, S.,... Feng, X. (2020). On-Surface Synthesis of Non-Benzenoid Nanographenes by Oxidative Ring-Closure and Ring-Rearrangement Reactions. Journal of the American Chemical Society, 142(31), 13565-13572. https://doi.org/10.1021/jacs.0c05668
MLA:
Lohr, Thorsten G., et al. "On-Surface Synthesis of Non-Benzenoid Nanographenes by Oxidative Ring-Closure and Ring-Rearrangement Reactions." Journal of the American Chemical Society 142.31 (2020): 13565-13572.
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