Communication: state mixing by spin-orbit coupling in the anionic chloroiodine dissociations

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Low-energy electron attachment to chloroiodine anion (ICl(-)) forms specific spin-orbit states.
• These states correlate with dissociative limits involving iodine and chlorine fragments.
• Understanding fragment angular distributions is key to probing molecular electronic structure.

Purpose of the Study:

• To investigate the influence of spin-orbit interactions on the electronic states of ICl(-).
• To analyze the symmetry of fragment angular distributions resulting from electron attachment.
• To develop a method for separating contributions from mixed electronic states.

Main Methods:

• Low-energy electron attachment to ICl.
• Analysis of fragment angular distributions.
• Theoretical evaluation of electronic state couplings and spin-orbit interactions.

Main Results:

• Three spin-orbit states of ICl(-) were identified in the Franck-Condon region.
• Significant spin-orbit interaction was found to induce Π-Σ mixing in the symmetry of fragment angular distributions.
• The experimental approach successfully separated contributions from different electronic states.

Conclusions:

• Spin-orbit interactions play a critical role in modifying the electronic state couplings and symmetry of ICl(-).
• The developed experimental method provides a quantitative means to evaluate configuration-interaction wavefunctions.
• This work advances the understanding of electronic structure and dissociation dynamics in molecular anions.