Studies on the relation between chemical constitution and ultraviolet absorption spectra of optically active and racemic compounds

Abstract

The ultraviolet absorption spectra of camphor-β -sulphonyl-phenyl, (o-, m- andp-) tolyl, (α - and β -) naphthylamides have been determined in methyl alcohol, ethyl alcohol, and chloroform. The absorption spectra of all the compounds show two absorption bands: one varying from 267 to 284 mµ, the longer absorption maximum (λ _max) due to selective absorption of the keto group, and the other shorter one, ranging from 226 to 230 mμ , due to general absorption of the saturated molecules. The values of the characteristic wavelengths, λ₀₈ obtained from Drude’s one-term equation, have been compared with the absorption maxima, λ_max., obtained by direct measurements. There are marked discrepancies in the values of λ₀ and λ_max. An explanation of the discrepancies is given. The nature of racemic modifications of the compounds has also been discussed.