Molecular structure, spectroscopic, solvatochromic, dyeing performance and biological evaluations of heterocyclic azo dye, 4-[(E)-(4-hydroxy-2-methylphenyl)diazenyl]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one

Abstract

A heterocyclic azo dye derived from 3H-pyrazol-3-one and m-cresol was synthesized and structurally confirmed by single crystal X-ray diffraction (SXRD) analysis along with UV–Vis, FT-IR and NMR spectroscopic techniques. This dye exists in azo tautomeric form which crystallizes in the orthorhombic Pbcn space group. However, in solution state, it predominantly exists in hydrazone tautomeric form as shown in the electronic absorption spectra. The influence of the acidic and basic media on the visible absorption spectra of that dye was also examined. The dyeing performance of the title compound on cotton yarn was appreciably good and show good fastness properties. The mutagenicity of the azo dye was screened by Ames salmonella/microsome assay. A considerable interaction observed with herring sperm-DNA, may be through a partial intercalation mode assessed by using electronic spectra. It also shows considerable biological activities such as antioxidant, anti-inflammatory and anti-arthritic activity with significant IC50 value, make it a promising drug candidate.