Carbohydrates as ligands: coordination equilibria and structure of the metal complexes

Simple sugars and their derivatives - with oxygen, nitrogen, sulphur or phosphorous anchoring donor groups - form metal ion complexes of various composition and stability. The emergence of new experimental methods allowed the assignment of the metal binding sites in the different isomeric complexes of these multidentate ligands, and also the determination of the most effective chelating isomers of the ligands - being present as a mixture of different conformational and/or configurational isomers in solution. We review the literature on the metal ion complexes of carbohydrate type ligands with the emphasis on the past 20 years, discussing the equilibria and structure in aqueous solution together with the structures determined for the solid state complexes. Stability and structural data are collected for comparison. (C) 2000 Elsevier Science S.A. All rights reserved.