Thermodynamics of complex formation with linear aliphatic tetramines. II. Heats and entropies of the reactions of 3,7-diaza-1,9-nonane-1,9-diamine with hydrogen ions and bivalent transition-metal ions

Free energies, enthalpies, and entropies of formation of Ni(II), Cu(II), Zn(II), and proton complexes of H2N(CH2)2NH(CH2)3NH(CH2)2NH2 were detd. calorimetrically at 25°. The high stability of the metal complexes was due to the enthalpy term even when the entropy term was favorable.