Delocalized π-Electrons and Odours

Abstract

THERE are several natural and synthetic compounds with odours which have been used to identify the substances. It has been noted¹ that for a substance to stimulate the sensory processes of the nerves it is necessary that some molecules leave the main part of the substance and pass into the nasal cavity. Amoore² considers in his steric theory of odours that airborne molecules are smelled when they fit into certain complementary receptor sites in the olfactory nervous system. Dyson³ suggested that there is a correlation between the osmic frequencies and the Raman shifts of the smelling body, because the latter shows evidence of intramolecular vibrations. Dyson¹ classifies smelling substances according to the presence of characteristic groups in the organic compounds.