PHOTOREACTION OF CRYSTAL VIOLET IN SOLUTION

Lightfastness of basic dyes and cationic dyes depends on substrates surrounding dyes. In order to learn origin we studied the photoreaction of Crystal Violet (CV) in alcohol and acetonitrile solutions as a model of substrate. Under degassed condition the photoreaction of CV was reduction to give its leuco compound in all used solvents. The photoreaction showed a remarkable dependence on wavelength of irradiated light, and CV excited state with ultraviolet irradiation is more active than that with visible light. In aerated solvents the photoreaction of CV was oxidation in acetonitrile, while reduction in alcohol.