Ultraviolet Absorption Spectra of o-, m- and p-Dinitrobenzene

Abstract In ethanol, m-dinitrobenzene shows the maximum absorption band at shorter wavelengths than nitrobenzene, while p-dinitrobenzene gives the absorption maximum at the wavelength near to that of nitrobenzene. These bands have briefly been discussed from the concept of the intramolecular charge transfer. The absorption curve of o-dinitrobenzene, indicating no absorption maximum but shoulders, are different from those of the other dinitrobenzenes, probably owing to steric hindrance by the adjacent large nitro groups.