Design, mesomorphic properties, and supramolecular organization of [60]fullerene-containing thermotropic liquid crystals

Two concepts have been developed for the design of [60]fullerene-containing thermotropic liquid crystals, namely, the covalent and non-covalent concepts. In the covalent approach, C-60 was functionalized with liquid-crystalline addends (malonate and aldehyde derivatives) by applying either the Bingel reaction or the 1,3-dipolar cycloaddition reaction. In the non-covalent approach, a liquid-crystalline inclusion complex was obtained from mesomorphic cyclotriveratrylene (CTV) derivatives and C-60. All of the covalent C-60 derivatives showed smectic A phases. In one case, an additional nematic phase was detected. The [C(60)subset of(CTV)(2)] complex gave rise to nematic-like and cubic phases. The covalent and noncovalent approaches demonstrate the various possibilities for C-60 to give rise to mesomorphic materials.