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

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Thorsten G. Lohr - , Professur für Molekulare Funktionsmaterialien (cfaed) (Autor:in)
  • José I. Urgel - , Swiss Federal Laboratories for Materials Science and Technology (Empa), Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia) (Autor:in)
  • Kristjan Eimre - , Swiss Federal Laboratories for Materials Science and Technology (Empa) (Autor:in)
  • Junzhi Liu - , The University of Hong Kong (Autor:in)
  • Marco Di Giovannantonio - , Swiss Federal Laboratories for Materials Science and Technology (Empa) (Autor:in)
  • Shantanu Mishra - , Swiss Federal Laboratories for Materials Science and Technology (Empa) (Autor:in)
  • Reinhard Berger - , Professur für Molekulare Funktionsmaterialien (cfaed) (Autor:in)
  • Pascal Ruffieux - , Swiss Federal Laboratories for Materials Science and Technology (Empa) (Autor:in)
  • Carlo A. Pignedoli - , Swiss Federal Laboratories for Materials Science and Technology (Empa) (Autor:in)
  • Roman Fasel - , Swiss Federal Laboratories for Materials Science and Technology (Empa), Universität Bern (Autor:in)
  • Xinliang Feng - , Professur für Molekulare Funktionsmaterialien (cfaed) (Autor:in)

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.

Details

OriginalspracheEnglisch
Seiten (von - bis)13565-13572
Seitenumfang8
FachzeitschriftJournal of the American Chemical Society
Jahrgang142
Ausgabenummer31
PublikationsstatusVeröffentlicht - 5 Aug. 2020
Peer-Review-StatusJa

Externe IDs

PubMed 32657120