Synthesis, characterization and solvatochromic behaviour of new water-soluble 8-hydroxy-3,6-disulphonaphthyl azohydroxynaphthalenes

A series of five tetracyclic mono azo dyes based on the diazotization 1-amino-8-hydroxynaphthalene-3,6-disulphonic acid and subsequent coupling with substituted (un)sulphonated naphthalene derivatives have been synthesized. The chemical structures were established using UV–visible, IR, NMR as well mass spectrometry. Based number sulphonic other hydrophilic groups they contain, compounds showed varying extent water solubility. Spectroscopic characterization revealed existence azo-hydrazone tautomerism influence solvating solvents equilibrium. Statistical analysis single, dual multiparametric equations Kamlet Abboud Taft parameters that solvent polarity was most significant contributor to observed spectral patterns in pure solvents. could find useful applications solvatochromic probes, food drug colour additives.