Synthesis, spectroscopic characterization and dyeing properties of new metal complexed azo dyes derived from gallic acid

New metal Mn (II), Fe (II), Ni (II), Cu (II), Zn (II) complexes of the dyes (Ligand I and Ligand II) obtained by coupling gallic acid with diazonium salt of 4-nitroaniline and p-aminophenol were obtained. The structures of the compounds were elucidated by spectroscopic methods (UV-VIS, FT-IR and MS), magnetic susceptibility and thermal analysis (TGA/DTG). According to the results of UV-VIS spectra obtained from DMF, methyl alcohol at pH: 2 and pH: 12, it was observed that the hydrazone tautomer structure was dominant in DMF and pH: 12, while the azo tautomer structure was dominant in pH: 2 and methyl alcohol. The existence of Octahedral geometry of the metal complexes was theoretically and experimentally supported by Tanabe-Sugano method and magnetic susceptibility, respectively. All synthesized dyes were applied to wool and polyester fabrics as reactive dyes using temperature and 1:20 Flotte ratio. Washing, rubbing (wet and dry) and light fastness were performed according to standard procedures, and fastness analysis results were dedected well to very well. In this study, fabrics were dyed with azo dyes and its metal complexes produced from gallic acid for the first time and the color codes, fastness properties of the dyed fabrics were revealed. The results of the present study indicated that the new azo derivative and their divalent metal complexes can be used as a future strategy for dyeing textile fibers and hightech applications.