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Structural progression in clusters of ionized water, (H2O)n=1-5(+)
Jonathan D Herr1, Justin Talbot, Ryan P Steele
1Henry Eyring Center for Theoretical Chemistry, Thatcher Building for Biological and Biophysical Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States.
The Journal of Physical Chemistry. A
|January 8, 2015
Summary
Oxidized water clusters show that hydronium cations and hydroxyl radicals separate in clusters of five or more molecules. This separation is driven by water
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Chemical Physics
Background:
- Ionized water clusters model water-splitting and postradiolytic events.
- Understanding ionized water cluster behavior is crucial for energetic applications and condensed-phase systems.
Purpose of the Study:
- To investigate the structures, properties, and energies of oxidized water clusters (H2O)n=1-5(+).
- To determine the size-dependent behavior of ionized water clusters and the factors influencing ion-radical pair separation.
Main Methods:
- Utilized equation-of-motion coupled-cluster theory approaches for theoretical calculations.
- Analyzed cluster energetics and solvation effects.
Main Results:
- Identified the formation of an ion-radical contact pair (OH···H3O+) in small clusters (n=1-4).
- Observed a propensity for ion-radical separation in clusters with n=5 molecules, consistent with experimental data.
- Determined preferential solvation of the hydronium cation by water as the primary driver for pair separation.
Conclusions:
- The transition to n=5 marks a critical size for ion-radical separation in oxidized water clusters.
- Preferential solvation is the key mechanism driving this separation, expected to continue in larger clusters and bulk water.
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