Binding of metal ions to polysaccharides. VI. Spectroscopic and potentiometric studies of the binding of copper(II) and nickel(II) to some monosaccharide units in acidic,neutral and alkaline aqueous media

Binding of Cu²⁺ and Ni²⁺ to glucosamine, N-acetyl- glucosamine and other derivatives of glucose was investigated in acidic, neutral and alkaline aqueous media using H⁺ and Cu²⁺ potentiometry and ligand- field and ESR spectroscopy. In neutral medium, site binding with copper(II) and nickel(II) occurs when the monosaccharide possesses a potentially coordinating amine or charged group not attached to C-1. At high pH, a coordination entity is only formed if the C-1 hydroxyl group can be deprotonated and other stabilizing groups are present. The role of groups attached to C-1 reflects the different behaviour of monosaccharides compared with polysaccharides.