Infrared spectroscopic studies on interactions in trifluoroacetic acid-sulfur dioxide systems

The method of frustrated multiple internal reflection (FMIR) infrared spectroscopy was used to study the nature of intermediates that formed upon oxidation of sulfur dioxide in trifluoroacetic acid (TFA) of various concentrations at 30°C. It was established that sulfur dioxide bound to a complex with TFA is oxidized by dissolved oxygen in systems that contain 99.9 and 55.5% trifluoroacetic acid.