Methanol Negative Ion Fragmentation Probed in Electron Transfer Experiments.

Area of Science:

• Atomic and Molecular Physics
• Chemical Physics
• Physical Chemistry

Background:

• Electron transfer processes are fundamental in chemical reactions.
• Understanding negative ion formation is crucial for various fields, including atmospheric chemistry and materials science.
• Methanol is a simple alcohol with significant chemical relevance.

Purpose of the Study:

• To comprehensively investigate negative ion formation from electron transfer in potassium-methanol collisions.
• To determine the types of negative ions produced and their energy dependence.
• To elucidate the underlying mechanisms of collision-induced fragmentation.

Main Methods:

• Experimental: Time-of-flight mass spectrometry was used to analyze negative ions formed.
• Experimental: Potassium cation energy loss spectra were measured.
• Theoretical: Quantum chemical calculations were performed on methanol's electronic states.

Main Results:

• Negative ions CH3O-, OH-, and O- were identified.
• Anion formation showed strong energy dependence, particularly at lower collision energies.
• OH- and CH3O- were the most intense fragment anions observed.
• Vertical electron affinities for accessible electronic states were determined to be -8.26 ± 0.20 and -10.36 ± 0.2 eV.
• Theoretical calculations supported the experimental findings regarding electronic states.

Conclusions:

• Potassium atom collisions effectively induce electron transfer and fragmentation in methanol molecules.
• The study provides detailed insights into the energy-dependent dynamics of negative ion formation.
• The findings contribute to a deeper understanding of fundamental atomic and molecular collision processes.