Synthesis, spectroscopic characterisation, corrosion inhibition studies and dyeing properties of lanthanide(III) complexes of 1-[(3-carboxyethyl-4,5-dimethylthiophen-2-yl)azo]-2-naphthol

Abstract

Ligational behaviour of the heterocyclic ligand obtained by coupling of diazotized 2-amino-3-carboxyethyl-4,5-dimethylthiophene with β-naphthol towards some selected lanthanide(III) ions has been studied. Various spectral and physico-chemical techniques have been used to confirm the coordination sites of the ligand (HTAN) and its lanthanide(III) complexes. It has been observed that these ligands coordinate to the metal ions in a neutral tridentate fashion. Thermal stability of metal chelates and structural stability of the chelating agent has been studied by thermal analysis. As lanthanides and azo dyes are reported as good corrosion inhibitors we have examined the corrosion inhibition activities of HTAN and its metal complexes. Also dyeing properties of the azo dye and some of its selected complexes towards cotton fabrics has been evaluated, as the traditional application field of the synthetic azo dyes still remains in the textile industry.