LIGHTFASTNESS AND SPECTROSCOPIC PROPERTIES OF N-SUBSTITUTED 1-AMINOANTHRAQUINONES

The fluorescence spectra and quantum yields of 1-acetylamino-, 1-monochloroacetylamino-, 1-benzoylamino- and 1-anilinoanthraquinones have been recorded in a variety of solvents. The dyes have also been examined using microsecond flash photolysis in ethyl acetate and 2-propanol. Fluorescence is observed from all the dyes except the 1-anilino derivative. On flash photolysis, all the dyes give strong transient absorption in 2-propanol whereas no transient absorption is observed in ethyl acetate. Interestingly, the 1-anilino derivative gives a very strong transient absorption due to the semiquinone radical (QH·) whereas the other three dyes give a strong transient absorption due to the radical anion (Q·-. These results are discussed in relation to the lightfastness of the dyes on polyester and nylon fibres. © 1979.