Vibration-spectral studies of compounds formed by the combination of methylformamide and dimethylformamide with some strong acids

Abstract

A determination of the infrared spectra of the solid hydrochlorides of methylformamide and dimethylformamide and of the Raman spectra of their aqueous solutions showed that certain spectral features change with the medium used. The infrared spectra of the two amides in concentrated and in aqueous sulphuric acid, and in concentrated hydrochloric acid (HCl and DCl), are consistent with the existence of two amide/acid reaction products for each amide: one (certainly ionic) form predominates in sulphuric acid solutions; a second form, of unknown structure, is present in the solid hydrochlorides, and in hydrochloric acid the two forms coexist in equilibrium.