Novel azobenzothiazole dyes from 2-nitrosobenzothiazoles

Novel azobenzothiazole dyes obtained by condensation of 2-nitrosobenzothiazoles with several substituted anilines were synthesized and characterized. The influence of solvent polarity on absorption spectra was examined, as was the relationship between dye structures and absorption in the UV–visible region. Azobenzothiazole dyes possessing an anilino unit which possessed an o-electron donating group, displayed unique absorption properties as revealed by a second, long wavelength absorption band.