B. Hirani et al., THERMOTROPIC LIQUID-CRYSTALLINE GLUCOSE DERIVATIVES WITH MESOGENIC SIDE-CHAINS, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 288, 1996, pp. 223-236
Many glucose derivatives have been studied so far for their liquid cry
stalline behavior. Penta-O-n-alkanoylglucopyranoses have been reported
to form discotic columnar mesophases. Thermotropic liquid crystals of
glucose with mesogenic side chains, consisting of a mesogen, an alkyl
spacer and a tail, form the subject of this study. The glucose deriva
tives were prepared by complete esterification of the hydroxyl groups
of glucose with the mesogenic side chains. Their characterization was
based on the analysis from cross polarizing microscopy, differential t
hermal calorimetery, wide-angle X-ray diffraction pattern and nuclear
magnetic resonance (both C-13 and H-1) spectra. Smectic and chiral nem
atic (cholesteric) phases have been observed in these macromolecules.
The effect on the phase behavior of varying the tail length in the sid
e chains of the molecule was studied. The structural arrangement of su
ch molecules has been proposed based on the observations. These are re
ported here as the first such observations of liquid crystalline phase
s in completely substituted chiral glucose molecules with mesogenic si
de chains.