Proton Tunneling in Acetic Acid Dimers

Abstract
The group theory of nonrigid systems is applied to determine the effects of proton tunneling in the vibrational spectrum of the dimer. It is shown that the doublet observed in the far‐infrared spectrum of the vapor is unlikely to be due to proton tunneling. This conclusion is confirmed by the observation that the doublet remains in the spectrum of (CH3COOD)2.