Novel mono-and bis-azo dyes containing the azulen-1-yl moiety:Synthesis,characterization,electronic spectra and basicity

摘要

3-and 4-[(Azulen-1-yl)-azo]-azo-benzenes were obtained in good yields using the buffered coupling reaction between several alkyl-substituted azulenes and diazotized phenylazo-phenylamines in dichloroacetic acid.The coupling products were characterized and the recorded electronic spectra are discussed.The isosbestic points obtained by protonation enabled the determination of their pK_a values.