Infrared and raman spectroscopy of carbohydrates

Abstract Laser-Raman spectra have been obtained from aqueous solutions of d -glucose, cellobiose, maltose, and dextran [(1 → 6)-α- d -glucan]. These four carbohydrates consist of one or more d -glucose residues, and their vibrational spectra are very similar. Comparison of the spectra of their solutions in water and deuterium oxide indicates that the Raman lines at approximately 1349, 1071, 1021, and 913 cm −1 (figures for d -glucose) for all four materials can be assigned modes related to the COH group. In addition, a number of modes related to CH have been identified by comparison of the infrared spectra of α- d -glucose and three C-deuterated d -glucoses in the solid state. Bands at 1457, 1337, 1219, and 1011 cm −1 for α- d -glucose are assigned to CH 2 -related modes, and those at 1404, 1360, 1250, 1076, 1047, 911, and 836 cm −1 to CH-related modes. The ratio of the frequency of an OH or CH deformation mode to that of the corresponding new band produced by deuteration is in the range 1.19±0.02 in most cases.