Development of Imidazolium-Based Parameters for AMOEBA-IL

Area of Science:

• Computational Chemistry
• Materials Science
• Physical Chemistry

Background:

• Accurate molecular modeling of ionic liquids (ILs) requires precise force fields.
• Developing transferable and efficient parametrization methods for polarizable IL potentials is crucial for expanding their applicability.
• Existing methods may lack efficiency or transferability for novel imidazolium-based cations.

Purpose of the Study:

• To present an efficient fragment-based approach for parametrizing the polarizable ionic liquid potential AMOEBA-IL.
• To develop transferable parameters for a range of imidazolium-based cations.
• To validate the new parameters through molecular dynamics simulations and comparison with experimental data.

Main Methods:

• Utilized Gaussian electrostatic model-distributed multipoles (GEM-DM) and quantum mechanics energy decomposition analysis (QM-EDA) for parameter development.
• Employed a fragment-based strategy to generate parameters for new imidazolium-based cations with varying alkyl chains.
• Validated parameters by comparing calculated intermolecular interactions (SAPT) and molecular dynamics simulation results (density, enthalpy of vaporization, RDF, diffusion coefficients) with QM references and experimental data.

Main Results:

• Successfully developed transferable AMOEBA-IL parameters for new imidazolium-based cations.
• Calculated gas-phase and bulk properties showed good agreement with QM references and experimental data.
• The new parametrization procedure proved straightforward and effective.

Conclusions:

• The proposed fragment-based approach offers an efficient and reliable method for generating AMOEBA-IL parameters for imidazolium-based cations.
• This method facilitates the accurate simulation of diverse ionic liquids, aiding in the design and prediction of their properties.
• The developed parameters enhance the predictive power of molecular simulations for ionic liquid systems.