PHOTOCHEMICAL DEGRADATION OF SOME AMINOAZOBENZENE AND RELATED 3-AMINO-5-NITRO(2,1)BENZISOTHIAZOLE-BASED DYES IN ETHANOLIC SOLUTION

This paper reports some kinetic measurements of the photofading in ethanol of some aminoazobenzene and related 3-amino-5-nitro(2,1)benzisothiazole-based disperse dyes derived from, as coupling components, derivatives of N-benzyl-N-phenyl-beta-alanine with different substituents in the benzyl or phenyl residue. A fair linear relationship between the measured fading rate and simga0 constants of ortho substituents in the phenyl ring was found. The influence of substituents in the benzyl group on the rate of fading was not noticeable.