A weakly coordinated water ligand is displaced in its place.
Completing the coordination sphere are two water ligands, with Cu-O distances of 2.20 Å (220 pm).
Most such complexes feature an additional water ligand, giving an overall coordination number of nine.
The closeness of these two residues would result in a steric hindrance preventing the water ligand from coordinating with zinc.
Solutions of metal aquo complexes are acidic owing to the ionization of protons from the water ligands.
The rapid exchange of this water ligand with bulk water is a major reason for the signal enhancing properties of the chelate.
Such salts contain a hydroxyl group that is directly bound to the metal ion in place of a water ligand.
In the hexahydrate, the Mg remains octahedral, but is coordinated to six water ligands.
Furthermore, the Na ion, with only a single positive charge, only weakly polarizes its water ligands.
Viewed as a coordination complex, the ion is octahedral, with oxo, four equatorial water ligands, and a monodentate sulfate.
