Related Experiment Video
Updated: Nov 21, 2025
09:35
Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
11.8K
Synthesis and characterization of [7]triangulene
Shantanu Mishra1, Kun Xu, Kristjan Eimre
1nanotech@surfaces Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland. roman.fasel@empa.ch pascal.ruffieux@empa.ch.
Nanoscale
|January 14, 2021
Summary
Researchers synthesized the largest triangulene, [7]triangulene, a molecule with potential for organic spintronic devices. On a copper surface, its high-spin state transforms into a closed-shell state due to charge transfer.
Area of Science:
- Organic Chemistry
- Materials Science
- Surface Science
Background:
- Triangulenes are non-Kekulé polyradical frameworks with high-spin ground states.
- These molecules are promising for organic spintronic applications.
Purpose of the Study:
- To synthesize and characterize the largest known triangulene homologue, [7]triangulene.
- To investigate the electronic properties of [7]triangulene on a metal surface.
Main Methods:
- Combined in-solution and on-surface synthesis.
- Low-temperature scanning tunneling microscopy (STM) for structural confirmation.
- Scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations for electronic properties.
Main Results:
- Successful synthesis of [7]triangulene (C78H24), a large polyradical framework.
- STM confirmed the molecular structure of adsorbed [7]triangulene on a Cu(111) surface.
- STS and DFT revealed chemisorption and charge transfer, leading to a closed-shell state, contrary to the predicted open-shell septet ground state in vacuum.
- Observed significant hybridization between the molecular orbitals of [7]triangulene.
Conclusions:
- The study reports the largest triangulene synthesized to date.
- On-surface chemisorption alters the electronic state of [7]triangulene from a predicted high-spin to a closed-shell state.
- This work provides insights into the behavior of polyradical molecules on surfaces, relevant for spintronic device development.
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