Synthesis and Chromogenic Properties of Some Water-Soluble 5-Nitro-2-pyridylhydrazones

Article abstract of DOI:10.1246/bcsj.63.3398

Four new water-soluble hydrazones, α-(5-nitro-2-pyridyl)hydrazono-α-(2-quinolyl)-3-toluenesulfonic acid, α-(5-nitro-2-pyridyl)hydrazono-α-(2-thiazolyl)-3-toluenesulfonic acid, α-(2-benzothiazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid, and α-(2-benzimidazolyl)-α-(5-nitro-2-pyridyl)hydrazono-3-toluenesulfonic acid, were synthesized.Their proton dissociation constants were determined spectrophotometrically.The chromogenic properties of the synthesized hydrazones and their reactions with metal ions were investigated spectrophotometrically in detail.The results revealed that the synthesized hydrazones react with various metal ions including transition metal ions, especially with cadmium(II), nickel(II), and zinc(II) to form stable colored comoplexes with very large apparent molar absorptivities, so that their were found to be all very useful as highly sensitive spectrophotometric reagents.