Large Amplitude Motions of Molecules and Ions Revealed by Supersonic Jet Spectroscopy

Abstract

Several laser electronic spectroscopies are applied for the study of large amplitude motions of aromatic molecules and ions in supersonic jets. The internal rotation of the $CH_{3}$ group in substituted toluenes in ground, excited and ionic states is mainly discussed. Large-amplitude ``butterfly tunneling” motion in 1,2,4,5-tetrafluorobenzene is also described.