Structural and Electronic Evolution of Ethanolamine upon Microhydration: Insights from Hyperfine Resolved Rotational...

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Ethanolamine is a crucial molecule in various chemical and biological processes.
• Understanding the hydration of ethanolamine is key to elucidating its behavior in aqueous environments.
• Previous studies have explored water clusters, but the specific hydration of ethanolamine requires detailed investigation.

Purpose of the Study:

• To identify and characterize ethanolamine hydrates with varying numbers of water molecules.
• To investigate the structural and electronic changes in ethanolamine upon hydration.
• To correlate hydrogen bond strength with spectroscopic properties.

Main Methods:

• Rotational spectroscopy was employed to identify ethanolamine hydrates.
• Accurate quantum chemical methods, including anharmonic vibrational corrections, were utilized for structural analysis.
• Nuclear quadrupole coupling constants of ¹⁴N were determined.

Main Results:

• Ethanolamine hydrates, from mono- to hepta-hydrates, were successfully identified.
• Significant conformational changes and formation of stable hydrogen bond networks were observed.
• A strong correlation was found between ¹⁴N nuclear quadrupole coupling constants and hydrogen bond strength.
• The seventh water molecule addition significantly increased ionicity towards protonated amine formation.

Conclusions:

• Microhydration plays a critical role in modifying the electronic environment of ethanolamine.
• The study provides insights into amine hydration dynamics and the influence of water on molecular structure.
• These findings contribute to a deeper understanding of solvation effects in chemical systems.