Liquid Crystalline Silsesquioxanes

Abstract

In order to study the effects of calamitic mesogenic units on the self-assembly of liquid crystalline phases in silsesquioxane supermolecules, various di- and tri- substituted silsesquioxane supermolecules have been prepared. They contain incompletely condensed silsesquioxanes substituted with a variety of alkyl chains. These moieties contain various calamitic mesogenic units including two-ring and three-ring terminally appended mesogenic units as well as laterally appended mesogenic units. These mesogenic units were prepared using hydrosilylation chemistry and the properties of these new compounds were elucidated using polarized optical microscopy, differential scanning calorimetry and single crystal X-ray diffraction techniques.

A novel octasilsesquioxane core has been prepared with two distinct moieties covalently bonded to it in order to study the effect of a non-mesogenic chiral entity along with a calamitic mesogenic group on the self-assembly of this mesogenic moiety in the liquid crystalline phase. This compound has been prepared using standard hydrosilylation techniques and its properties have been elucidated using polarized optical microscopy and differential scanning calorimetry.