On-Surface Synthesis of Non-Benzenoid Nanographenes by Oxidative Ring-Closure and Ring-Rearrangement Reactions

Lohr, Thorsten G.; Urgel, José I.; Eimre, Kristjan; Liu, Junzhi; Di Giovannantonio, Marco; Mishra, Shantanu; Berger, Reinhard; Ruffieux, Pascal; Pignedoli, Carlo A.; Fasel, Roman; Feng, Xinliang (2020). On-Surface Synthesis of Non-Benzenoid Nanographenes by Oxidative Ring-Closure and Ring-Rearrangement Reactions. Journal of the American Chemical Society, 142(31), pp. 13565-13572. American Chemical Society 10.1021/jacs.0c05668

Preview	Text Ring-rearrangement_MS_postprint.pdf - Accepted Version Available under License Publisher holds Copyright. Download (1MB) | Preview
	Text jacs.0c05668.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (9MB)

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.

Interest & Impact

Downloads

278 since deposited on 03 Feb 2021
84 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item