Modeling of the structure and IR spectrum of methyl-?-D-glucopyranoside by the density functional method

摘要

A theoretical study has been made of the structure and IR spectrum of methyl-?-D-glucopyranoside with allowance for the influence of a hydrogen bond on them. Structural dynamic models of a free methyl-?-D-glucopyranoside molecule and its simplest complexes with the hydrogen bond, which represent variously structured dimmers, have been constructed by a density-functional method using a B3LYP functional in a 6-31G (d) basis. Energies have been minimized; structures, electrooptical parameters, force constants, and frequencies of normal modes in a harmonic approximation and their intensities in IR spectra have been calculated; hydrogen-bond energy has been evaluated. From the calculation results, the IR spectrum of a methyl-?-D-glucopyranoside sample has been interpreted and the conclusions on its structure and spectrum formation, and also on the capabilities of the employed method of densityfunctional theory have been drawn.