Shiva Mohan Verma

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

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 (λmax) 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, λmax obtained by direct measurements. There are marked discrepancies in the values of λ0 and λmax. An explanation of the discrepancies is given.The nature of racemic modifications of the compounds has also been discussed.