Solvent and Substituent Effects on the Electronic Spectra of 3-Arylazo-Imidazo[1,2- b ]pyrazolo[4,3- d ]-pyridazines

A series of new 3-arylazo-6-methyl-2,8,9-triphenyl-8H-imidazo[1,2-b]pyrazolo[4,3-d]pyridazines was prepared via reaction of hydrazonoyl halides with 3-hydrazonoacetyl-4-cyano-1,5-diphenylpyrazole. The structures of the compounds prepared were confirmed by spectral and elemental analyses. The solvatochromic and substituent effects on the absorption spectra of these azo dyes were interpreted by correlation of absorption frequencies with Kamlet–Taft and Hammett equations, respectively.