Shape and Core-Excited Resonances in Thiophene

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Understanding electron-molecule interactions is crucial for fields like plasma physics and atmospheric chemistry.
• Thiophene is a key heterocyclic compound with applications in materials science and pharmaceuticals.

Purpose of the Study:

• To comprehensively investigate resonance formation in electron collisions with thiophene.
• To compare theoretical calculations with experimental measurements for electron impact excitation cross sections.

Main Methods:

• Utilizing the ab initio R-matrix method for detailed theoretical calculations.
• Performing absolute differential cross section measurements for electron impact excitation up to 18 eV.
• Analyzing electron scattering at specific angles (90° and 135°).

Main Results:

• Excellent agreement was found between calculated and measured experimental cross sections.
• Identification and characterization of three known shape resonances (two π* and one σ*) and several core-excited or mixed-character resonances.
• Experimental confirmation of several core-excited resonances.

Conclusions:

• The study validates theoretical models for electron-thiophene interactions.
• Provides experimental evidence for core-excited resonances, linking them to previous dissociative electron attachment (DEA) experiments.
• Enhances the understanding of electron scattering dynamics in heterocyclic molecules.