Molecular Crystals and Liquid Crystals, Vol.498, 19-28, 2009
Molecular Organization Realized by Soft Character of Smectic Layer
Liquid-crystalline smectic phases possess a layered structure which is so soft that the structure sometimes deforms and changes into a three dimensional ordered or disordered inter-connected structure. The "sponge'' is a disordered phase, whereas the "smectic Q'' is an ordered one, both of which were found to appear in highly chiral thermotropic systems. The structures and properties of the sponge phase were investigated by the microscopic, X-ray diffraction and visco-elastic measurements and the soft nature of the phase is confirmed. Both of the phases are produced only if the optical purity of the compound is high enough, in which the stability of the smectic Q phase was found to be more sensitive to the optical purity than that of the sponge phase.