Excess enthalpies of aqueous solutions of monosaccharides at 298.15 K: Pentoses and 2-deoxy sugars

The heats of dilution in water of some pentoses (D-arabinose, D-lyxose, and D-ribose) and 2-deoxy sugars (2-deoxy-D-ribose, 2-deoxy-D-galactose, and 2-deoxy-D-glucose) were determined at 298.15 K. The calculated excess enthalpies were compared with those of isomeric and enantiomeric monosaccharide solutions and with those of sugar derivatives, oligosaccharides and other oxygenated compounds in water. All the excess thermodynamic properties of sugars and their derivatives show a characteristic behavior among the nonelectrolytes in water and suggest, together with other thermodynamic properties, that their aqueous solutions are ruled predominantly by solute-solvent interactions. Since new data are at present available, a refinement of the results of the Savage and Wood group contribution method is carried out. The group contributions to the second virial coefficients hii of the excess enthalpies of sugars, alcohols, ethers, and ketones in water are now recalculated and critically discussed. The differences among the isomers, which cannot be predicted by the method, are correlated with the differences in the stereochemistry of the solute molecules. © 1983 American Chemical Society.