What Is Special about Aromatic-Aromatic Interactions? Significant Attraction at Large Horizontal Displacement
Dragan B Ninković1, Jelena P Blagojević Filipović1, Michael B Hall2
1Innovation Center of the Faculty of Chemistry in Belgrade, Studentski trg 12-16, Belgrade 11001, Serbia.
ACS Central Science
|April 2, 2020
Summary
Benzene-cyclohexane interactions are stronger than benzene-benzene at close distances. However, benzene-benzene interactions maintain strength over longer distances, explaining aromatic ring recognition in biological structures.
Area of Science:
- Computational chemistry
- Physical chemistry
- Molecular interactions
Background:
- Aromatic ring interactions are crucial in biological systems, including protein folding and supramolecular assembly.
- Understanding the nature of these interactions at a molecular level is essential for predicting and designing complex structures.
Purpose of the Study:
- To compare the interaction strengths and ranges between benzene-cyclohexane and benzene-benzene systems.
- To elucidate the role of aromatic ring recognition in larger molecular contexts.
Main Methods:
- High-level *ab initio* calculations were employed to model the interactions.
- Analysis of interaction energies and their dependence on horizontal displacement was performed.
Main Results:
- Benzene-cyclohexane stacking is 17% stronger than benzene-benzene at optimal configurations.
- Benzene-benzene interactions retain significant strength at larger horizontal displacements (5.0 Å) compared to benzene-cyclohexane.
- The radius of attraction for benzene-benzene is 250% larger than for benzene-cyclohexane.
Conclusions:
- Aromatic rings exhibit a significant recognition capability over relatively large distances.
- This long-range aromatic recognition mechanism contributes to the stability and function of proteins and supramolecular structures.
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