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Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids BPCA
Published on: May 16, 2016
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Coarse-graining the structure of polycyclic aromatic hydrocarbons clusters
J Hernández-Rojas1, F Calvo2, D J Wales3
1Departamento de Física and IUdEA, Universidad de La Laguna, 38205, La Laguna, Tenerife, Spain. jhrojas@ull.es.
Physical Chemistry Chemical Physics : PCCP
|April 9, 2016
Summary
Polycyclic aromatic hydrocarbons (PAHs) form essential soot components. This study models PAH clusters using coarse-grained potentials, revealing 1D columnar structures and unique sandwich motifs in mixed aggregates, crucial for understanding interstellar carbon matter.
Area of Science:
- Computational Chemistry
- Astrochemistry
- Materials Science
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) are significant carbon components in interstellar dust and soot.
- Understanding PAH aggregation is key to modeling interstellar carbon matter and soot formation.
Purpose of the Study:
- To develop and validate a coarse-grained model for simulating PAH molecules and their aggregates.
- To investigate the structural properties of pure and mixed PAH clusters.
- To explore PAH interactions with graphitic surfaces.
Main Methods:
- Parameterization of coarse-grained potentials using all-atom reference data.
- Basin-hopping global optimization for identifying low-energy cluster structures.
- Inclusion of quadrupolar interactions to assess their structural impact.
Main Results:
- Coarse-grained models accurately reproduce atomistic results for coronene and circumcoronene clusters.
- Identified low-energy structures consist of 1D columnar motifs, with π-stacking dominating binary aggregates.
- Predicted novel sandwich motifs in mixed PAH clusters and flat triangular monolayers on graphitic substrates.
Conclusions:
- Coarse-grained modeling provides an efficient method for studying large PAH systems.
- PAH aggregation is primarily driven by π-stacking, forming diverse structures.
- PAHs exhibit stronger binding to graphitic surfaces than to themselves, influencing their arrangement.
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