Structural Expansion of Cycloheptafluorene towards Azulene‐Embedded Non‐Benzenoid Nanographenes

• Published in: Chemistry : a European journal 2023-09, Vol.29 (51)
• Main Authors: Wu, Fupeng, Barragán, Ana, Gallardo, Aurelio, Yang, Lin, Biswas, Kalyan, Écija, David, Jesús I Mendieta‐Moreno, Urgel, José I, Ma, Ji, Feng, Xinliang
• Format: Article
• Language: English
• Subjects: Anthracene; Atomic force microscopy; Azulene; Chemistry; Density functional theory; Dynamic structural analysis; Fabrication; Fluorene; Metal surfaces; Molecular dynamics; Precursors; Reaction products; Scanning tunneling microscopy
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202301739

Non‐benzenoid non‐alternant nanographenes (NGs) have attracted increasing attention on account of their distinct electronic and structural features in comparison to their isomeric benzenoid counterparts. In this work, we present a series of unprecedented azulene‐embedded NGs on Au(111) during the attempted synthesis of cyclohepta[def]fluorene‐based high‐spin non‐Kekulé structure. Comprehensive scanning tunneling microscopy (STM) and non‐contact atomic force microscopy (nc‐AFM) evidence the structures and conformations of these unexpected products. The dynamics of the precursor bearing 9‐(2,6‐dimethylphenyl)anthracene and dihydro‐dibenzo‐cyclohepta[def]fluorene units and its reaction products on the surface are analyzed by density functional theory (DFT) and molecular dynamics (MD) simulations. Our study sheds light on the fundamental understanding of precursor design for the fabrication of π‐extended non‐benzenoid NGs on a metal surface.Dedicated to Professor Maurizio Prato on the occasion of his 70th birthday