Does Thermochemical Mimicry Extend to Gibbs Energies? The Differences of K+ and NH4+, and of Na+ and H3O+
Springer Verlag (Germany)
A while ago we presented the concept of thermochemical mimicry  in the context of the energetics of complexation of K+ and NH4+ in a variety of environments and showed there was a remarkable similarity . The difference of enthalpies of formation of salts as found in the solid state and in aqueous solution were shown to be nearly the same, and additionally nearly equal to the value for the free gaseous ions. The lattice energies of these salts were also shown to be nearly identical as were the complexation energy of these gaseous ions with a variety of type and number of ligands. The ion mobility of K+ and NH4+ as found as salts in a variety of media were also shown to be very nearly the same. Recently we have become acquainted with yet another, though quite old and conceptually unique, similarity: These two ions have comparable effects on food thickeners . This result excited us and so encouraged a relooking at these two ions and their energetics.
Does Thermochemical Mimicry Extend to Gibbs Energies? The Differences of K+ and NH4+, and of Na+ and H3O+ J.F. Liebman, S. Scheiner Struct. Chem. 1999 10 391-392