Direct Observation of Anionic Yields from the Liquid-Vapor Interface by Electron Irradiation

Area of Science:

• Physical Chemistry
• Radiation Chemistry
• Surface Science

Background:

• Dissociative electron attachment (DEA) is crucial for understanding ionizing radiation damage to bioorganic molecules.
• DEA fundamentals are primarily studied in the gas phase, but its behavior in aqueous solutions remains debated.

Purpose of the Study:

• To investigate the mechanisms of DEA processes in liquid methanol.
• To provide experimental evidence for DEA in liquid environments, specifically at the liquid interface.

Main Methods:

• Utilized electron-impact-time-delayed mass spectrometry.
• Studied DEA in liquid methanol, focusing on the liquid interface and bulk.

Main Results:

• Methoxide ion (CH3O-) is the predominant product in liquid methanol DEA, particularly at the liquid interface.
• DEA occurs with both primary and secondary low-energy electrons at the interface.
• Primary low-energy electrons in the liquid bulk tend to be solvated, not directly participating in DEA.

Conclusions:

• The study reveals distinct DEA mechanisms in liquid methanol compared to gas and solid phases.
• Findings offer new insights into radiation chemistry relevant to biological systems.