RESONANCE RAMAN-SPECTRUM OF CRYSTAL VIOLET

The preresonance Raman spectra, taken under various conditions, of crystal violet have been obtained using the exciting lines of an Ar+ laser. The analysis of the Raman data and of the IR and UV visible absorption spectra allowed us to determine the structure of the ion (propeller‐like in shape with D3 symmetry), to characterize the unstable single protonated dye cation, and to propose a detailed vibrational assignment in terms of coupled vibrations of the substituted benzenes. In addition, the measurements of the Raman excitation profiles furnished information on the vibronic couplings and provided evidence for a close correlation in the resonance mechanisms between crystal violet and benzene and its monosubstituted derivatives. Copyright © 1979 Heyden & Son Ltd.