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Photoelectron angular distribution in valence shell ionization of heteroaromatic molecules studied by the continuum
Yoshi-Ichi Suzuki1, Toshinori Suzuki
1Chemical Dynamics Laboratory, RIKEN, Wako 351-0198, Japan.
The Journal of Physical Chemistry. A
|January 4, 2008
Summary
Photoelectron angular distributions were calculated for heteroaromatic molecules. Results show energy-dependent asymmetry in pi orbitals and invariant sigma orbitals, aligning with experiments.
Area of Science:
- Quantum Chemistry
- Molecular Physics
- Spectroscopy
Background:
- Understanding electron behavior in molecules is crucial for chemistry and physics.
- Photoelectron spectroscopy provides insights into molecular electronic structure.
- Heteroaromatic molecules are fundamental in various chemical and biological systems.
Purpose of the Study:
- To calculate and analyze photoelectron angular distributions for valence shell ionization of key heteroaromatic molecules.
- To investigate the energy dependence of asymmetry parameters for different orbital types (pi, sigma, nonbonding).
- To compare theoretical calculations with experimental findings and interpret observed trends.
Main Methods:
- Utilizing the continuum multiple scattering Xalpha (MS-Xα) method for theoretical calculations.
- Focusing on valence shell ionization processes.
- Analyzing asymmetry parameters (beta values) derived from photoelectron angular distributions.
Main Results:
- Calculated asymmetry parameters show strong energy dependence for ionization from pi orbitals.
- Asymmetry parameters are nearly invariant with energy for ionization from sigma orbitals.
- Ionization from nonbonding orbitals generally yields higher asymmetry parameters compared to bonding orbitals.
- Theoretical results demonstrate good agreement with available experimental data.
Conclusions:
- The study successfully models photoelectron angular distributions in heteroaromatic systems.
- Observed trends in asymmetry parameters are explained by Coulomb phase and molecular frame photoelectron angular distribution.
- The findings enhance the understanding of electronic structure and ionization dynamics in these important molecules.
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