Solvation Thermodynamics of Solutes in Water and Ionic Liquids Using the Multiscale Solvation-Layer Interface...

Area of Science:

• Computational chemistry
• Molecular modeling
• Thermodynamics

Background:

• Molecular assembly in solution is governed by thermodynamics.
• Explicitly modeling bulk solvent is computationally inefficient.
• Accurate solvation free energy calculations are crucial for molecular design.

Purpose of the Study:

• Develop and assess novel multiscale solvation models.
• Improve the prediction of solvation thermodynamic properties.
• Enable accurate calculations for complex molecular systems.

Main Methods:

• The SLIC/CDC model combines continuum electrostatics (SLIC) with statistical thermodynamics for hydrogen bonding and nonpolar interactions (CDC).
• The SLIC/SASA model integrates the SLIC electrostatic model with solvent-accessible surface area (SASA) for nonpolar energy.
• Both models were parametrized and validated using experimental data and explicit-solvent molecular dynamics simulations for 500 solutes.

Main Results:

• The SLIC/CDC model achieved an average accuracy better than 1 kcal/mol for Gibbs energies of solvation in water compared to experiments.
• SLIC/CDC showed better than 0.8 kcal/mol accuracy against explicit-solvent simulations.
• The improved SLIC/SASA model demonstrated better than 1.4 kcal/mol accuracy in aqueous systems and 1.6 kcal/mol in ionic liquids.

Conclusions:

• Both SLIC/CDC and SLIC/SASA models provide accurate predictions of solvation Gibbs energies.
• These models are the first implicit solvation models capable of predicting solvation entropies and heat capacities.
• The developed models significantly advance the computational prediction of solvation thermodynamics.