Rotational analysis of naphthol-aromatic ring complexes stabilized by electrostatic and dispersion interactions

Area of Science:

• Physical Chemistry
• Molecular Spectroscopy
• Supramolecular Chemistry

Background:

• Aromatic complexes exhibit diverse geometries influenced by substitution.
• Understanding intermolecular forces is key to predicting complex structures.

Purpose of the Study:

• Investigate the structural impact of heteroatoms and alkyl groups in naphthol-aromatic ring complexes.
• Analyze the role of intermolecular forces, such as hydrogen bonding and π-π interactions, in complex formation.

Main Methods:

• Broadband rotational spectroscopy was employed to determine the precise structures of three naphthol-aromatic ring complexes.
• Symmetry-adapted perturbation theory (SAPT) calculations were performed to analyze interaction energies.

Main Results:

• Experimentally determined structures revealed O-H⋯O/O-H⋯π interactions as dominant.
• The nature of the heteroatom in the five-membered ring significantly altered complex symmetry and intermolecular interactions.
• SAPT calculations indicated similar contributions of dispersion and electrostatic forces to complex stabilization.

Conclusions:

• Heteroatom and alkyl group substitutions demonstrably influence the geometry and intermolecular interactions of naphthol-aromatic complexes.
• Hydrogen bonding and dispersion forces play crucial roles in the aggregation of substituted aromatic systems.