Thermodynamic Investigation and Mixed Ligand Complex Formation of 1,4-Bis-(3-aminopropyl)-piperazine and Biorelevant Ligands

Table 3

Atomic number, ionic radius, electronegativity, and ionization potential of the investigated bivalent metal ion^a.

Metal ion	Co^2+	Ni^2	Cu^2+	Zn^2+
Atomic number	27	28	29	30
Ionic radius (pm)	79	72	71	74
Electronegativity	1.88	1.91	2.00	1.65
Second ionization energy (kJ/mol)	1646	1753	1958	1733

^aValues from [30].