Conformation and S=O Stretching Absorptions of Simple Sulfoxides

Abstract
The infrared S=O stretching absorptions of several simple sulfoxides have been measured. Some sulfoxides show one absorption maximum, whereas others show two. These results may be attributed to the rotational isomerism about the S–C axis. Convincing evidence for this conclusion has been obtained by the measurement of the spectra of methyl isopropyl sulfoxide at various temperatures.