Deprotonation patterns of disaccharides in coordinating cellulose solvents: A status report

Crystals of metal complexes of deprotonated open-chain oligosaccharides which may serve as models for the action of coordinating cellulose solvents on the polysaccharide molecule, are generally harder to obtain in a quality suitable for X-ray analysis than in the case of monosaccharides. Four preliminary crystal structure analyses are presented which settle the significance of intramolecular hydrogen bonds towards the metal ligating accepters. The metal binding sites of sucrose include both 1,2- and I,3-diolato complex formation, whereas alpha,alpha-trehalose has been found in the 1,2-diolato coordination mode.