Synthesis, characterization, solvatochromic study, and application of new heterocyclic monoazo acid dyes

摘要

Heterocyclic amines were diazotized and coupled with 8-anilinonaphthalene-1-sulfonic add magnesium salt to synthesize some new heterocyclic monoazo dyes, showing ammonium-azonium tautomerism. The structures of the dyes were characterized by H-1-NMR, MALDI, FTIR, and UV-Visible spectroscopy. The solvatochromic behavior of the dyes was assessed in solvents of different polarities. Ammonium-azonium tautomerism was also investigated, and the dyes were found to exist as a mixture of tautomers. In addition, the effect of acid on the visible absorption spectra, and the tautomeric equilibrium was also reported. The resultant dyes were applied on silk at 1/1 standard depth, and were checked for different fastness properties. (C) 2019 Elsevier B.V. All rights reserved.