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Updated: Jul 4, 2026
06:35
Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Triple Pancake Bonding in Neutral π-Conjugated Dimers: a Computational Study
Li-Juan Cui1, Miklos Kertesz2, Zhong-Hua Cui1,3
1Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
Journal of the American Chemical Society
|July 2, 2026
Summary
Researchers created a neutral molecule that forms a rare triple pancake bond through π-orbital overlap. This discovery offers new insights into high-order π-stacking interactions in molecules.
Area of Science:
- Materials Science
- Quantum Chemistry
- Supramolecular Chemistry
Background:
- High-order pancake bonding is rare in π-conjugated molecules.
- Previous studies on hexaazatrinaphthylene trianions ([HAN]3-) showed triple pancake bonds but were obscured by counterions.
Purpose of the Study:
- To design a neutral hexaazatrinaphthylene derivative for studying intrinsic triple pancake bonding.
- To investigate the nature and stability of intermolecular interactions in the neutral system.
Main Methods:
- Designed a neutral HAN derivative, 1,5,9-trihydro-1,4,5,8,9,12-hexaazatriphenylene (HATH3).
- Utilized computational methods to analyze the electronic structure and bonding in HATH3 dimers.
- Calculated intermolecular separation and interaction energies for cofacial arrangements.
Main Results:
- HATH3 exists in a quartet ground state with three singly occupied π-orbitals.
- HATH3 monomers form stable dimers in trans- and cis-cofacial arrangements with ultrashort intermolecular distances (2.968 and 2.971 Å).
- Triple pancake bonds are formed via three-electron sharing π-orbitals, with significant interaction energies (-158.6 and -135.1 kJ/mol).
Conclusions:
- Neutral HATH3 dimers exhibit genuine triple pancake bonds, clarifying high-order π-stacking interactions.
- Orbital interactions are the primary drivers of stability, supplemented by electrostatic and dispersion forces.
- These findings are crucial for understanding aggregate and crystal formation driven by strong intermolecular forces.
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