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Low-energy electron collisions with thiophene
R F da Costa1, M T do N Varella, M A P Lima
1Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-170 Santo André, São Paulo, Brazil.
The Journal of Chemical Physics
|May 24, 2013
Summary
Low-energy electron collisions with thiophene molecules reveal shape resonances in π∗ anion states. These findings align with experimental data and suggest a general electron attachment feature in similar heterocyclic compounds.
Area of Science:
- Atomic and Molecular Physics
- Quantum Chemistry
- Electron Scattering Theory
Background:
- Understanding electron-molecule interactions is crucial for chemical processes.
- Thiophene, a five-membered heterocyclic compound, exhibits complex electronic structures.
- Previous studies on similar molecules like pyrrole and furan provide context for thiophene's behavior.
Purpose of the Study:
- To investigate elastic integral, momentum transfer, and differential cross sections for low-energy electron collisions with thiophene.
- To identify and characterize shape resonances in thiophene using theoretical calculations.
- To compare the observed resonances with experimental data and related heterocyclic compounds.
Main Methods:
- Utilized the Schwinger multichannel method for scattering calculations.
- Employed static-exchange and static-exchange plus polarization approximations.
- Calculations covered electron energies from 0.5 eV to 6 eV.
Main Results:
- Identified two π∗ shape resonances at 1.00 eV and 2.82 eV (in static-exchange plus polarization approximation).
- Observed a σ∗ shape resonance with d-wave character around 2.78 eV.
- Results show good agreement with experimental electron transmission spectroscopy data.
Conclusions:
- Electron attachment to π∗ molecular orbitals is a characteristic feature of thiophene.
- The findings support the existence of both π∗ and σ∗ shape resonances in thiophene.
- Electron scattering resonances in thiophene are comparable to those in pyrrole and furan, indicating a general trend in five-membered heterocycles.
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