Spontaneous Assembly and Three-Dimensional Stacking of Antiaromatic 5,15-Dioxaporphyrin on HOPG
Journal
Angewandte Chemie (International ed. in English)
Journal Volume
61
Journal Issue
48
Pages
e202212726
Date Issued
2022-11-25
Author(s)
Chen, Tsang-Wei Matt
Tanaka, Yuki
Kametani, Yohei
Cheng, Kum-Yi
Lin, Chih-Hsun
Lin, Yi Rick
Hsu, Ting-Rong
Chen, Zuqian
Hao, Jiping
Mori, Shigeki
Shiota, Yoshihito
Yoshizawa, Kazunari
Furuta, Hiroyuki
Shimizu, Soji
Abstract
Antiaromatic compounds have recently received considerable attention because of their novel properties such as narrow HOMO-LUMO gaps and facile formation of mutual stacking. Here, the spontaneous assembly of antiaromatic meso-2-thienyl-substituted 5,15-dioxaporphyrin (DOP-1) is scrutinized at the liquid-solid interface by scanning tunneling microscopy (STM). Polymorphism in monolayers characterized by the orthogonal and parallel assemblies is found at the low concentration of 0.05 mM. The parallel assembly is more stable and dominantly formed at higher concentrations. Aggregation was observed at concentrations >0.2 mM, and the STM images of the aggregates implied the formation of stacked layers. The intrinsic electronic structures of the mutually stacked bilayer generated by applying an electric pulse to the monolayer were probed by scanning tunneling spectroscopy to reveal the narrowing of the HOMO-LUMO gap by about 20 % compared with the monolayer, thus suggesting significant molecular orbital interactions.
Subjects
Antiaromaticity; Heteroporphyrinoids; STM; STS
Publisher
WILEY-V C H VERLAG GMBH
Type
journal article