Supermolecular Liquid Crystals - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 58

matic medium, provided that enough mesogenic sub-units are available in the
dendritic addend, without markedly suppressing the liquid-crystalline state.
When the number density of the mesogens is increased, thereby reducing
the weight fraction of fullerene units in the supermolecular structure, see 59
in Fig. 69, the liquid crystal phases become increasingly more stable and the
spherical fullerene unit becomes increasingly hidden within the liquid crys-
tal matrix [125]. This result indicates that the liquid crystal units have the
ability to incorporate and organize non-mesogenic functional units into the
self-organizing state, without too much detriment to the liquid crystal itself.
Thus, we can apparently control the periodic ordering of non-mesogenic
functional units through the process of self-organization. Similar approaches
recently have been taken by Sakai and Matile [126] and Zhuravel et al. [127],
but in both of these cases, amino acids were used to induce self-assembly, and
ultimately self-organization.
3.3
Complex Functional Multipedes
Current research by Kato, Stoddart and Sauvage has demonstrated how
the self-organization properties of liquid crystals can be used in the self-
assembling of functional systems to give an oriented and organized bulk
material [128, 129]. Figure 70 shows a novel system, 60 , where the proper-
ties of liquid crystals have been combined with that of rotaxanes to create
a self-organizing molecular switch [128]. This material self-organizes to give
a smectic A phase, which has a temperature range from 7 to 146 ◦ C. Bistable
switching was observed through examination of the electrochemical response
which was characterized by cyclic voltammetry.
Fig. 70 A self-organizing rotaxane system, 60 , which forms a smectic A phase
4
Summary
In this brief review, we have demonstrated the potential for creating a wide
variety of novel supermolecular materials with designer structural and func-
tional properties. In our own development of new materials we have borne in