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Published on: September 18, 2016
Aromaticity of closed-shell charged polybenzenoid hydrocarbons
Nicolás Ramos-Berdullas1, Slavko Radenković, Patrick Bultinck
1Department of Physical Chemistry, University of Vigo, Lagoas-Marcosende s/n, 36310 Vigo, Spain.
The Journal of Physical Chemistry. A
|May 17, 2013
Summary
Charged polybenzenoid hydrocarbons (PBHs) exhibit significant aromatic stabilization, comparable to neutral PBHs. These aromatic cations show substantial electron delocalization and may form in combustion conditions and interstellar environments.
Area of Science:
- Physical Chemistry
- Theoretical Chemistry
- Aromaticity Studies
Background:
- Polybenzenoid hydrocarbons (PBHs) are organic molecules with complex aromatic structures.
- Understanding the aromaticity of charged species is crucial for predicting their stability and reactivity.
- Previous studies have focused on neutral PBHs, leaving charged variants less explored.
Purpose of the Study:
- To investigate the aromatic stabilization of closed-shell charged polybenzenoid hydrocarbons (PBHs).
- To compare the aromaticity of these cations with their neutral counterparts.
- To explore the potential role of these aromatic cations in astrophysical environments and photoluminescence.
Main Methods:
- Energetic and magnetic aromaticity criteria were employed.
- Direct measures of electron delocalization, including topological resonance energies, ring current maps, and multicenter delocalization indices, were calculated.
- Graph theoretical models were used to analyze the aromatic features.
Main Results:
- Closed-shell polybenzenoid cations exhibit a degree of aromaticity comparable to neutral PBHs.
- Significant electronic delocalization and aromatic stabilization were observed in all investigated cations.
- A strong diatropic peripheral electron current was detected, indicating robust aromaticity.
- Graph theoretical models successfully described the aromatic features, relating them to neutral PBHs.
Conclusions:
- Closed-shell charged PBHs are significantly aromatic and stabilized.
- These findings support the potential existence and stability of such species under combustion conditions and in the interstellar medium.
- The study suggests that these aromatic fragments could be involved in phenomena like extended red emission.
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