Intermolecular Coulombic decay in small biochemically relevant hydrogen-bonded systems.

Area of Science:

• Physical Chemistry
• Quantum Chemistry
• Biophysics

Background:

• Intermolecular Coulombic decay (ICD) is a crucial relaxation mechanism for ionized and excited molecules.
• Inner-valence ionization triggers ICD and related phenomena in molecular systems.
• Hydrogen-bonded networks are prevalent in biological systems and influence molecular processes.

Purpose of the Study:

• To investigate intermolecular Coulombic decay (ICD) in various small hydrogen-bonded systems.
• To explore ICD initiated by inner-valence ionization in biologically relevant complexes.
• To estimate the potential genotoxic impact of ICD-emitted electrons in aqueous biological environments.

Main Methods:

• Utilized high-precision ab initio methods for computational analysis.
• Optimized molecular geometries of hydrogen-bonded complexes.
• Computed single- and double-ionization spectra to analyze ICD processes.

Main Results:

• Analyzed ICD in seven types of hydrogen-bonded systems, including water-water and water-solute complexes.
• Determined the energy distribution of emitted ICD electrons.
• Calculated the kinetic energy of fragment ions resulting from ICD.

Conclusions:

• ICD is a significant decay pathway in small hydrogen-bonded systems.
• The study provides insights into ICD processes relevant to biological tissues.
• ICD-emitted low-energy electrons may pose a genotoxic risk in biological systems.