| Popis: |
In this paper, we investigate the possibility of scaling, on a reference molecule, the force field computed by means of a semiempirical quantum chemical method, here PM3, and transferring the scaling factors to other parent molecules. The scaling, performed on α- d -glucose, allows good prediction of the vibrational spectra of β- d -glucose, α- d -galactose, α- d -mannose, methyl-α- d -glucopyranoside, methyl-α- d -mannopyranoside, cellobiose and gentiobiose within 20 cm −1 in the high and medium frequency range. Low frequency bands are less well reproduced, but they are also less widely used to characterize these molecules. The influence of the crystal field and intermolecular hydrogen bonds is discussed. The method can be extended to other chemical families. |
Full Text from ScienceDirect