In recent years the design of chemical structures of liquid-crystalline materials has developed rapidly, and in many cases changed radically. Since Reinitzer's days, liquid crystals have either been classed as rodlike or disclike, with combinations of the two leading to phasmidic liquid crystals. The discovery that materials with bent molecular structures exhibited whole new families of mesophases inspired investigations into the liquid-crystal properties of materials with widely varying molecular topologies-from pyramids to crosses to dendritic molecules. As a result of conformational change, supermolecular materials can have deformable molecular structures, which can stabilize mesophase formation, and some materials that are non-mesogenic, on complexation form supramolecular liquid crystals. The formation of mesophases by individual molecular systems is a process of self-organization, whereas the mesophases of supramolecular systems are formed by self-assembly and self-organization. Herein we show 1) deformable molecular shapes and topologies of supermolecular and self-assembled supramolecular systems; 2) surface recognition processes of superstructures; and 3) that the transmission of those structures and their amplification can lead to unusual mesomorphic behavior where conventional continuum theory is not suitable for their description.

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The optical behaviour of surface-stabilized ferroelectric liquid crystal samples cannot be described using a uniform director profile. The simplest model based on the chevron layer structure and the surface alignment is a triangular director profile. Analytical expressions for the resulting transmitted light were calculated using the Jones matrix formalism and fitted to experimental data results of a smectic-C host made using an optical multichannel analyser (OMA). This simple model gives an excellent fit, with results that are consistent with X-ray measurements of the chevron structure.

A large flexoelectric polarization might be expected for a bent-core nematic liquid crystal, due to the combination of molecular shape and transverse dipole component. In this study a bent-core nematic compound is doped to be highly chiral, and measurements of the difference in flexoelectric coefficients (e(1)-e(3)) are carried out by exploiting the chiral flexoelectro-optic effect. The measured flexoelectric coefficients are greater than those for many conventional calamitic nematics, but several orders of magnitude lower than recent reports on other bent-core compounds. The influence of the bent molecular shape on the nematic phase is evident from measurements of the elastic constants, where an unusually low ratio of k(3) to k(1) indicates that bend distortions of the director are relatively lower in energy compared to those involving splay.