A novel series of nickel (II) azo dye complexes of 5-(4-methoxyphenylazo)-2-thioxo-
4-thiazolidinone (HL 1), 5-(4-methylphenylazo)-2-thioxo-4-thiazolidinone (HL 2), 5-
(phenylazo)-2-thioxo-4-thiazolidinone (HL 3) and 5-(4-nitrophenylazo)-2-thioxo-4-
thiazolidinone (HL 4) were prepared and characterized elemental analyses, IR, UV–Visible 
spectra, X-ray diffraction analysis and mass spectra as well as thermogravimetric analysis 
(TGA)