N-Hydroxyamide-Containing Heterocycles. Part 5. Synthesis of Novel Hexadentate Ligands Composed of N-Hydroxy-2(1H)-pyrazinone, Aliphatic Diamine, and 1,1,1-Tris(carboxyethoxymethyl)ethane, and Properties of Their Ferric Complexes

Article abstract of DOI:10.1016/0040-4020(95)00839-Z

Novel hexadental ligands (3HOPRnCMe) containing N-hydroxy-2(1H)-pyrazinone connected to tricarboxylic acid by an aliphatic diamine through amide bonds were synthesized.UV-vis spectra of the 1:1 molar mixtures of 3HOPRnCMe and ferric ion in aqueous solution and the mole ratio plot strongly supported the formation of intramolecular 1:1 ferric complexes.The relative stability constants (log K 20.6-21.7) of the complexes were affected by the spacer length in a molecule.Further, 3HOPRnCMe showed higher iron removal efficiency toward human transferrin than naturally occurring siderophore, desferrioxamine B.