Simulations of imidazolium ionic liquids: when does the cation charge distribution matter?
R M Lynden-Bell1, T G A Youngs
1Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK.
Summary
Models of dimethylimidazolium chloride (dmimCl) show that cation charge distribution impacts equilibrium properties. However, ion dynamics, like diffusion, are significantly influenced by chloride ion polarizability.
Area of Science:
- Physical Chemistry
- Computational Materials Science
- Ionic Liquids
Background:
- Understanding the behavior of ionic liquids like dimethylimidazolium chloride (dmimCl) is crucial for their application.
- Intermolecular potentials and charge distribution significantly influence material properties.
Purpose of the Study:
- To compare properties of liquid and crystal models of dmimCl using various intermolecular potentials.
- To investigate the impact of cation charge distribution and chloride ion polarizability on dmimCl properties.
Main Methods:
- Development and comparison of multiple force field models for dmimCl.
- Inclusion of 'realistic' and 'unrealistic' cation charge distributions.
- Utilizing shell models to investigate chloride ion polarizability.
Main Results:
- Equilibrium properties (energetics, structure, charge screening) are sensitive to cation charge distribution.
- Polarizability has minimal effect on equilibrium properties.
- Dynamical properties, particularly diffusion, are strongly affected by chloride ion polarizability.
Conclusions:
- Cation charge distribution is a key factor for equilibrium properties in dmimCl.
- Chloride ion polarizability plays a critical role in the dynamics of dmimCl, especially diffusion.
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