Lab lore about keeping transition metals happy in solution.
- Phosphate is bad news, as it is forms insoluble complexes with basically any divalent cation.
- Cu(II) likes to form insoluble complexes with chloride and water. Always make up fresh aqueous Cu(II) stocks for measurements.
- Tris, TES, and imidazole all chelate Cu(II) in solution, which will prevent precipitation. In a binding experiment, the energy to remove the metal from solution must be taken into account.