Bulletin of the Chemical Society of Japan · 1977 · 12 citations · 5 references
Natural SciencesChemistryOrganic ChemistrySpectroscopic AnalysisSpectroscopyAbsorption SpectroscopyInfrared SpectroscopyMolecular SymmetryNear-infrared SpectroscopyOptical SpectroscopyVibrational SpectroscopyInfrared Absorption SpectraInfrared SpectraIntermolecular Electron TransferVibrational Band StructureVibrational BandsVibrational FrequenciesVibrational ModesWave Number
Abstract Dimorphic forms were isolated for over ten derivatives of 2-anilino-1,4-naphthoquinone, 2-anilino-3-chloro-1,4-naphthoquinone, and 2-anilino-3-bromo-1,4-naphthoquinone carrying substituents on the phenyl ring. One of the two forms exhibits a relatively sharp vibrational band near 3300 cm−1, the other, a relatively broad band at a lower wave number. The spectra in the region from 700 to 1700 cm−1 are often markedly different from each other. In several instances, the two forms are differently colored. This difference is attributed to the appearance of, or a change in the intensity of, an intermolecular charge-transfer absorption band. Not only the dimorphic forms, but also most of the derivatives examined, could be classified into two groups on the basis of the location and the sharpness of the vibrational band appearing in the region from 3150 to 3350 cm−1.
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