Supermolecular Liquid Crystals - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 31

esting non-linear physical properties, e.g., antiferroelectric, pyroelectric, and
piezoelectric properties.
The next family of materials, which are to be discussed all possess
cyanobiphenyl moieties as the mesogenic units. The systematic studies of the
liquid crystal properties are described in terms of spacer length and peripheral
number density. The first material, 37 , shown in Fig. 35, is an octamer based
on the octasilsesquioxane core unit [86]. This material was prepared and puri-
fiedinsuchawaythatbyHPLCand 29 Si NMR spectroscopy it was shown to be
a single compound without dispersity. The material was found to exhibit smec-
tic polymorphism with SmC and SmA phases being formed. The incorporation
of cyanobiphenyl mesogenic moieties means that the material has interesting
Fig. 35 Octamer of octasilsesquioxane, 37 , bearing cyanobiphenyl moieties