Solvent Effect on Cation⊗3π Interactions: A First-Principles Study

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Biophysics

Background:

• Cation–π interactions are vital in biological systems and materials science.
• The influence of solvation on these interactions is not well understood.

Purpose of the Study:

• To investigate how water molecules affect cation–π interaction strengths.
• To elucidate the mechanisms behind solvation effects on cation–π systems.

Main Methods:

• Examined sequential water molecule attachment to cation–π systems (Li⁺, Na⁺, K⁺).
• Analyzed interaction mechanisms including cation–π, π–π, water–π, water–ion, and water–water interactions.
• Employed Ab initio Molecular Dynamics (AIMD) simulations.

Main Results:

• Solvation of metal cations weakens cation–π interactions; solvation of benzene strengthens them.
• Water molecules modulate Coulombic and charge distribution interactions.
• Water–water interactions generally destabilize the systems, while other interactions enhance stability.

Conclusions:

• Solvation significantly alters cation–π interaction strengths through specific molecular interactions.
• Findings offer insights into the structure and strength of cation–π interactions in aqueous environments.
• AIMD simulations confirm the practical relevance of these findings.