Current Status of AMOEBA-IL: A Multipolar/Polarizable Force Field for Ionic Liquids.

Erik Antonio Vázquez-Montelongo,G Andrés Cisneros,José Enrique Vázquez-Cervantes

doi:10.3390/ijms21030697

Erik Antonio Vázquez-Montelongo, G Andrés Cisneros + Show 1 more

Open Access

https://doi.org/10.3390/ijms21030697

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Abstract

Computational simulations of ionic liquid solutions have become a useful tool to investigate various physical, chemical and catalytic properties of systems involving these solvents. Classical molecular dynamics and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations of IL systems have provided significant insights at the atomic level. Here, we present a review of the development and application of the multipolar and polarizable force field AMOEBA for ionic liquid systems, termed AMOEBA–IL. The parametrization approach for AMOEBA–IL relies on the reproduction of total quantum mechanical (QM) intermolecular interaction energies and QM energy decomposition analysis. This approach has been used to develop parameters for imidazolium– and pyrrolidinium–based ILs coupled with various inorganic anions. AMOEBA–IL has been used to investigate and predict the properties of a variety of systems including neat ILs and IL mixtures, water exchange reactions on lanthanide ions in IL mixtures, IL–based liquid–liquid extraction, and effects of ILs on an aniline protection reaction.

Highlights

The study of ionic liquid (IL) solutions by means of molecular dynamics (MD) or Monte Carlo (MC) computational simulations have become a useful tool to study these systems
A large number of studies have been devoted to the modeling of ILs by MD based on these force fields (FFs) [10,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66]
These two possible mechanisms were studied using two different configurations for the system: configuration 1 was obtained by restraining the distance of one IL ion pair to the solute in the quantum mechanical/molecular mechanical (QM/MM) optimization of snapshots taken from MD simulations

Summary

Introduction

The study of ionic liquid (IL) solutions by means of molecular dynamics (MD) or Monte Carlo (MC) computational simulations have become a useful tool to study these systems These approaches can provide significant insights on structural, thermodynamic and transport properties. Most FFs for ILs approximate the intermolecular electrostatic interaction by using a collection of fixed (generally atom–centered) point charges This approximation results in the neglect of important effects including charge density anisotropy, charge density overlap, induction and other many body effects. One approach to implicitly introduce these effects involves the use of ab initio Born–Oppenheimer MD to calculate average partial charges for a variety of ILs, resulting in non–integer values on each ion This approach has shown significant charge transfer occurs and calculated properties are in better agreement than integer atomic partial charges [60,78]. The use of AMOEBA–IL to simulate the MM environment in the QM/MM investigation of an aniline protection reaction is presented in Section 6, followed by concluding remarks

AMOEBA–IL Parametrization

Water Exchange Dynamics on Lanthanide Cations

Liquid–liquid Extraction of Benzene from Dodecane–Benzene Mixture

Findings

Conclusions