Syntheses of azulen-1-yl-benzothiazol-2-yl diazenes

Azulen-1-yl-benzothiazol-2-yl diazenes substituted at thiazole and/or at azulene moiety have been prepared by diazotization of the corresponding benzothiazol-2-ylamines in inorganic acid mixtures or dichloroacetic acid followed by diazonium salts' coupling with azulenes. The nitrosyl sulfate was also used for the synthesis of diazonium salts. The systematic substitution of pattern structure enabled us to study the interdependence between the polarity of different obtained chromophores and their physical characteristics such as the electronic and NMR spectra. Because the NLO response of chromophores is related to the compound solvatochromism, this property of diazenes was also taken into account.