Imidazole in Aqueous Solution: Hydrogen Bond Interactions and Structural Reorganization with Concentration

Area of Science:

• Computational chemistry
• Molecular dynamics simulations
• Physical chemistry

Background:

• Existing computational models for imidazole have limitations in accurately describing electrostatic interactions.
• Accurate modeling of imidazole-water interactions is crucial for understanding its behavior in solution.

Purpose of the Study:

• To develop and validate a new, improved force field for imidazole in aqueous solutions.
• To investigate the structural and dynamic properties of imidazole in water at various concentrations.

Main Methods:

• Classical molecular dynamics (MD) simulations.
• Ab initio molecular dynamics (AIMD) simulations, including Car-Parrinello MD.
• Development and reparametrization of a new imidazole force field with an extra site for the lone pair.

Main Results:

• The new force field accurately reproduces imidazole-water hydrogen bonding patterns.
• The model successfully predicts the experimental water/octanol partition coefficient and imidazole crystal structure.
• Simulations reveal detailed insights into imidazole-water and imidazole-imidazole interactions and molecular arrangements.

Conclusions:

• The developed force field offers a significant improvement for simulating imidazole in aqueous environments.
• This work provides a more accurate computational tool for studying imidazole's behavior in solution.
• The findings contribute to a better understanding of solvation effects and molecular interactions of imidazole.