Hydrogen Bond Dynamics in the Solvation Shell on Proton Transfer in Aqueous Solution

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Solution Chemistry

Background:

• Proton transfer (PT) is fundamental in aqueous solutions.
• Understanding hydrogen bond (HB) dynamics is crucial for PT mechanisms.
• The structure of hydronium (H3O+) and its solvation shell influences PT.

Purpose of the Study:

• To investigate the detailed hydrogen bond (HB) dynamics during proton transfer (PT) in aqueous solution.
• To analyze the role of solvation shells in the proton transfer process.
• To elucidate the behavior of water molecules around hydronium (H3O+).

Main Methods:

• Utilizing molecular dynamics (MD) simulations.
• Employing the multistate empirical valence bond (MS-EVB) model.
• Analyzing hydrogen bond dynamics in solvation shells.

Main Results:

• Water molecules in the hydronium (H3O+) first solvation shell break accepted HBs to maintain a distorted Eigen (H9O4+) configuration.
• Cleavage and formation of accepted HBs are critical for driving PT.
• Proton transfer leads to inequivalent water-donated and -accepted HBs around H3O+.

Conclusions:

• The study provides insights into the molecular mechanisms of proton transfer in water.
• Hydrogen bond dynamics in solvation shells are essential for proton transfer events.
• The excess proton significantly influences the hydrogen bonding network around hydronium (H3O+).