Deuterium NMR studies of n-alkyl-β-D-glucopyranosides liquid-crystalline systems

Abstract

Liquid-crystalline systems consisting of n-alkyl-β-D-glucopyranosides (heptyl to dodecyl) and solutes (water, n-octanol, benzene and methylene dichloride) have been studied by measurement of the deuterium NMR quadrupolar splittings. Particular attention was given to the system of n-octyl-β-D-glucopyranoside (OG)-solute for which the OG-water and the OG-benzene phase diagrams were determined. Information about the orientational order of the aliphatic chain was obtained from deuterium NMR measurements of chain deuteriated OG. The order parameter profiles for the chain in this molecule were calculated using a quantitative theoretical model. A qualitative model served to interpret the dependence of the splittings in different solutes upon their concentration. DSC and preliminary X-ray data supplement the NMR measurements