Mixed-Ligand Complexes of Manganese(II), Cobalt(II), Nickel(II), Zinc(II), and Copper(II) with ATP and Threonine

Complex formation in the systems M(II)-ATP-L-threonine-water, where M(II) is Mn(II), Co(II), Ni(II), Zn(II), or Cu(II), was studied by potentiometric titration. The stability constants for the complexes of the composition 1:1:1 were determined. Mixed-ligand complexes M(C10H15N5P3O13)(C 4H8NO3) ·4H2O were synthesized from aqueous solutions of the ligands and metal hydroxides. According to IR spectroscopy (400-4000 cm-1), the ligands are coordinated to the metal ions: chemical equation presented.