Dissociative electron attachment to benzoic acid (C₇H₆O₂)

Area of Science:

• Physical Chemistry
• Chemical Physics
• Molecular Physics

Background:

• Benzoic acid is an important organic compound.
• Dissociative electron attachment (DEA) is a key process in molecular physics.
• Understanding DEA provides insights into molecular fragmentation.

Purpose of the Study:

• To investigate the dissociative electron attachment (DEA) process in benzoic acid (C6H5COOH).
• To identify the primary dissociation channels and negative ion fragments produced.
• To elucidate the nature of DEA resonances, particularly at higher energies.

Main Methods:

• Experimental setup utilizing a crossed beam apparatus with a quadrupole mass spectrometer and a trochoidal electron monochromator.
• Measurement of relative partial cross sections for DEA to benzoic acid.
• Comparison of experimental DEA data with ultraviolet photoelectron spectroscopy (UPS) of benzoic acid.
• Supportive density functional theory (DFT) calculations for threshold energy determination.

Main Results:

• Identified main dissociation channels for benzoic acid under DEA.
• Observed DEA bands at higher energies were attributed to Feshbach resonances.
• These resonances involve the double occupation of diffuse Rydberg-like orbitals.
• Experimental findings were consistent with DFT calculations of threshold energies.

Conclusions:

• The study clarifies the mechanisms of DEA to benzoic acid.
• Feshbach resonances play a significant role in DEA, especially at higher electron energies.
• The findings contribute to a deeper understanding of electron-molecule interactions and molecular fragmentation pathways.