Infrared Absorption in Acetanilide by Solitons

The infrared spectrum of acetanilide shows a new band that is red shifted from the main amide-I maximum by about 15 ${\mathrm{cm}}^{\ensuremath{-}1}$, the intensity of which increases at low temperature. It is suggested that this band may arise from the creation of amide-I solitons that are similar (but not identical) to those proposed by Davydov for the alpha helix in proteins.