Solvation dynamics in Ni+ (H2O)n clusters probed with infrared spectroscopy

Area of Science:

• Physical Chemistry
• Spectroscopy
• Materials Science

Background:

• Water clusters are fundamental systems for understanding hydrogen bonding.
• Nickel-water complexes offer a unique platform to study ion-water interactions.
• Infrared photodissociation spectroscopy provides detailed insights into molecular structure and bonding.

Purpose of the Study:

• To investigate the O-H stretching vibrations in mass-selected Ni+(H2O)n clusters.
• To identify the onset and evolution of hydrogen bonding with increasing cluster size.
• To characterize the structural changes and network formation within these complexes.

Main Methods:

• Utilizing infrared photodissociation spectroscopy.
• Analyzing mass-selected Ni+(H2O)n complexes.
• Examining spectral features in the O-H stretching region (up to n=25).

Main Results:

• Evidence for hydrogen bonding appears at n=4, marked by red-shifted bands.
• A broader hydrogen-bonded network evolves with increasing cluster size.
• By n=10, all water molecules are integrated into the hydrogen-bonded network.
• Symmetric OH stretch diminishes, while asymmetric stretch forms a doublet.

Conclusions:

• Nickel-water clusters exhibit significant hydrogen bonding as they grow.
• The formation of a hydrogen-bonded network is observed, distinct from clathrate structures.
• Spectroscopic data provides a detailed molecular-level understanding of water cluster formation around a metal ion.