Tautomerism (as prototropy) involving migration of a cation; the
breaking off of an ion, such as a hydrogen ion or metal ion, from a
molecule so that a negative ion remains in equilibrium.
Cationotropy refers to the ability of a molecule or ligand to change its coordination number around a central cation based on its chemical environment. This can lead to different possible coordination geometries for the cation depending on the molecules or ligands surrounding it.