Carbohydrate liquid crystals even at ambient temperature

Abstract

The dialkyl dithioacetals of D-glucose, L-rhamnose, o-mannose, o-galactose, D-arabinose, D-xylose, and D-lyxose have been prepared, and with the exception of rhamnose, all exhibit liquid crystalline behaviour; the transition points for phase changes are strongly dependent o n stereochemistry.

Synthesis and mesogenic properties of several homologous series of aldose dialkyl dithioacetals. A model for their behaviour

“…This only holds true for moderate chain lengths. The clearing points reach their maximum for R = n-dodecyl or n-tridecyl [2]. Longer chains have a tendency to coil, which leads to destabilization of the layer.…”

“…We are interested in this relationship between the configuration of the carbohydrate moiety and liquid-crystalline properties. In addition there has been no agreement so far on the nature of the mesophase formed (smectic B [l], smectic A,, [2] or perhaps even a discotic mesophase [3]). We decided therefore to subject the aldose S,S-acetals to a more thorough examination.…”

Glycolipids from natural sources: dry liquid crystal properties, hydrogen bonding and molecular mobility of Palm Kernel oil mannosides

“…Spectroscopic assignation to particular hydroxyl groups within the polar heads is complicated in glycosides, due to the large number of interactions occurring in the polar domains of their smectic layers [55,56,57], which may comprise intramolecular, and intermolecular inter-and intra-layer interactions, see Figure 8 [41,58]. Hence, as an attempt to further discriminate the nature and strength of the different hydrogen bonds in ManPKO, we have fit the 3600-3000 cm -1 region to three Gaussian peaks that account for different hydroxyl groups: free, at high frequencies, v >3500 cm -1 , and weakly and strongly hydrogen bonded,  max~3 410 cm -1 and  max~ cm -1 , respectively, see Figure 9(a).…”

Self-Assembly of Unusually Stable Thermotropic Network Phases by Cellobiose-Based Guerbet Glycolipids

“…Supramolecular network morphologies stemming from the self-assembly of molecular amphiphiles offer opportunities for the bottom-up construction of materials with applications including organic semiconductors and energy storage media, size-selective molecular separations membranes, membrane-bound protein crystallization platforms, , and internally structured lipid nanoparticles for therapeutic delivery. , Exemplified by functional bicontinuous double gyroid (DG), double diamond, and other periodic networks, applications of these materials crucially depend on their interpenetrating, labyrinthine nanochannels with tailored chemical constitutions and physical properties. These intricate self-assembled structures are known to arise from thermotropic self-assembly of various liquid crystal (LC) mesogens comprising chemically dissimilar segments of widely varied structures, including polycatenars, rod-like polyphiles, , wedge-shaped molecules, disk-like molecules, bolamphiphiles, , and glycolipids. − However, these thermotropic phases often form only with restricted molecular compositions and in narrow thermal stability windows, since the negative Gaussian (“saddle splay”) curvature microdomain interfaces of these assemblies exhibit substantial mean curvature deviations that result in molecular packing frustration. − The lack of robust molecular designs that drive mesoscale network self-assembly substantially curtails exciting current and future applications of these nanostructures.…”