Electron transfer collisions with oriented trifluoroacetic acid (CF3CO2H)

Area of Science:

• Physical Chemistry
• Chemical Physics
• Molecular Collisions

Background:

• Understanding electron transfer in molecular collisions is crucial for reaction dynamics.
• Steric effects in collisions with oriented molecules provide insights into reaction mechanisms.

Purpose of the Study:

• To investigate electron transfer collisions between potassium (K) atoms and oriented trifluoroacetic acid (CF(3)CO(2)H) molecules.
• To determine the preferred collision orientation and the electronic orbitals involved in electron transfer.

Main Methods:

• Utilized crossed molecular beams to study collisions between neutral K atoms and neutral, oriented CF(3)CO(2)H molecules.
• Analyzed ion products using time-of-flight mass spectrometry at center-of-mass energies from 6 to 18 eV.

Main Results:

• Electron transfer predominantly forms K(+) and trifluoroacetate (CF(3)CO(2)(-)) ions.
• The reaction is favored when K atoms attack the positive (-CO(2)H) end of the molecule, indicating steric asymmetry.
• Evidence suggests initial electron transfer into the pi*(CO) orbital, followed by migration to the sigma*(OH) orbital, leading to O-H bond cleavage.

Conclusions:

• The steric asymmetry in K + CF(3)CO(2)H collisions provides a detailed view of the electron transfer pathway.
• Orbital symmetry and perturbation by the nascent K(+) ion play key roles in directing the reaction and bond breaking.