Heteroligand nickel(II) and palladium(II) complexes with amino acids and ATP

Complexation in the nickel(II) or palladium(II)-ATP-amino acid (α-alanine, serine, aspartic acid, glutamic acid) system was studied by pH titration. The stability constants of the 1:1:1 complexes were determined. Stability of the heteroligand complexes varies in the order Asp > Glu > Ser > Ala. Heteroligand complexes Ni(ATP-)(Ala-) ·2H2O, Ni(ATP-)(Ser-)·2H 2O, Ni(ATP-)(Asp-)·2H2O, Ni(ATP-)(Glu-)·2H2O, Pd(ATP 2-)(Ala), Pd(ATP2-)(Ser), Pd(ATP2-)(Asp), and Pd(ATP2-)(Glu) were synthesized from aqueous solution.