SF₆ Negative Ion Formation in Charge Transfer Experiments

Area of Science:

• Physical Chemistry
• Chemical Physics
• Atomic and Molecular Collisions

Background:

• Extends previous ion-pair formation studies on K + SF6 collisions.
• Addresses the complex intramolecular energy redistribution in temporary negative ions.

Purpose of the Study:

• To update and extend previous ion-pair formation studies of K + SF6 collisions.
• To investigate fragment anion formation and energy loss spectra.
• To support experimental findings with quantum chemical calculations.

Main Methods:

• Time-of-flight mass spectrometry to detect fragment anions.
• Collisions conducted over a wide energy range (10.7–213.1 eV).
• Quantum chemical calculations for unoccupied molecular orbitals.

Main Results:

• SF5- is the dominant anion (>70% yield), followed by SF6- and F-.
• Minor anions include SF3- and F2-, with trace S-.
• Energy loss spectrum of potassium cations provides insights into collision dynamics.

Conclusions:

• Experimental and theoretical results elucidate the mechanisms of anion formation in K + SF6 collisions.
• The role of resonances and Rydberg states in anion formation is highlighted.
• Provides a comprehensive understanding of the collision dynamics and fragmentation pathways.