Supermolecular Liquid Crystals - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 51

drimers [102-105], shape-persistent macromolecules [106], and polar col-
loidal particles [107] are abiotic examples of such materials that self-organize,
like proteins, in a pre-programmed fashion.
A recent molecular design, “Janus” liquid-crystalline molecular materi-
als in the form of segmented structures that contain two different types of
mesogenic units has recently been reported [108, 109]. Janus materials fa-
vor different types of mesophase structure, grafted onto the same scaffold,
to create giant molecules that contain different hemispheres (“Janus” refers
to materials with two faces, such as fluorocarbon/hydrocarbon or hydro-
philic/hydrophobic, etc., for example Janus amphiphilic dendrimers have
been reported [110-114]).
The complementary materials 52 and 53 , based on a central scaffold made
up of pentaerythritol and tris(hydroxymethyl)aminomethane units linked
together, where one unit carries three cyanobiphenyl (CB) (smectic prefer-
ring), see Fig. 61, and the other three chiral phenyl benzoate (PB) (chiral
nematic preferring) mesogenic moieties, see Fig. 62, or vice-versa were inves-
tigated [115], see Fig. 63.
Fig. 61 Janus liquid crystal 52
Fig. 62 Janus liquid crystal 53