Reparameterization of Polarizable Force Fields for Studying Ion Transfer across Liquid-Liquid Interfaces

Area of Science:

• Computational Chemistry
• Physical Chemistry
• Materials Science

Background:

• Accurate simulation of liquid-liquid interfaces is crucial for understanding chemical processes.
• Ab initio molecular dynamics (AIMD) provides high accuracy but is computationally expensive.
• Classical polarizable force fields offer a computationally efficient alternative but require accurate parameterization.

Purpose of the Study:

• To develop a general scheme for refining classical polarizable molecular dynamics (MD) force fields for liquid-liquid interfaces.
• To enable accurate and efficient simulations of molecular interactions at interfaces.
• To investigate the mechanism of ion transfer across liquid-liquid interfaces.

Main Methods:

• Parameterization of classical polarizable force fields using AIMD reference data.
• Minimization of relative entropy and root mean squared deviation in atomic forces.
• Application of multiscale models to study chloride ion transfer across water-dichloromethane (DCM) interface.

Main Results:

• Developed accurate classical polarizable force fields for liquid-liquid interfaces.
• Calculated free-energy barrier for ion transfer across water-DCM interface, consistent with existing results.
• Demonstrated that electronic polarizability is key for phase-transfer catalysts to lower ion transfer barriers.

Conclusions:

• The developed parameterization scheme is a general route for modeling various liquid-liquid interface systems.
• Accurate force fields are essential for understanding interfacial phenomena and designing new catalysts.
• This method allows for efficient simulations of complex interfacial systems where AIMD is infeasible.