Sur l'identification par infrarouge des groupes immonium

Abstract

The identification by I.R of the cation CN +H is usually based on the immonium bands and on the CN + stretching vibration. An extensive literature survey and our own results in the 2-pyrazolinium series, show that these criteria are questionable and cannot be extensively applied, especially in the case of protonation site assignment of the nitrogenous bases [1]. Lastly we have given the exact assignment of the NH deformation bands for the immonium group belonging to a non aromatic molecule.