Calculation of the structure and IR spectrum of hydrogen-bonded methyl-β-D-glucopyranoside by the density-functional method

The IR spectrum and structure of methyl-β-D-glucopyranoside have been studied theoretically taking into account the influence on them of the hydrogen bond formed in the sample. Density-functional theory with the B3LYP functional in basis 6-31G(d) was used to minimize the energies and calculate the structures, electro-optical parameters, force constants, frequencies of normal harmonic vibrations, and intensities in IR spectra of the simplest H-bonded dimeric complexes of methyl-β-D-glucopyranoside. The calculated spectra of H-bonded complexes were compared with those of the free molecule and the experimental spectrum in the range 400–3700 cm –1 . Conclusions about the structure of methyl-β-D-glucopyranoside were made. The interpretation of its IR spectrum was refined.