Infrared and Raman spectra, conformational stability, ab initio calculations of structure, and vibrational assignment of α and β glucose

alpha and beta Glucose anomers were studied by using density functional/ab initio calculations in vacuum and in the presence of a solvent (water). Calculations in a continuum medium, using the Onsager reaction field model, suggest that alpha glucose is energetically most stable than beta anomer in aqueous solution according with the experimentally reported. We also calculated the vibrational frequencies and optimal geometries for both glucose anomers, showing differences between them, depending on the medium around the molecule. The vibrational frequencies calculated are compared with experimental results obtaining very good agreement. (C) 2004 Elsevier B.V. All rights reserved.