Chirally Homogeneous and Heterogeneous Dendritic Liquid Crystals

• Published in: Macromolecules Vol. 46; no. 4; pp. 1268 - 1273
• Main Authors: Belaissaoui, A, Saez, I. M, Cowling, S. J, Goodby, J. W
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 26.02.2013
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts; Dendrimer; End group; Optically active polymer; Branched polymer; Aromatic polymer; Ester polymer; Thermotropic state; Chiral compound; Experimental study; Oligomer; Phase transitions; Allylation; Monodispersed polymer; Biphenyl derivatives; Liquid crystal polymers; Preparation; Glycoside
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma3026332

We have coupled methyl α-d-glucoside (G) and methyl α-d-mannoside (M) as the chiral structural variant moieties in the core and at the branching sites within dendritic scaffolds surrounded by 12 cyanobiphenyl mesogens (CB). Systematic studies of the influence of the chiral moieties on thermal and mesomorphic properties were carried out by positional permutation approach of the pyranose units G and M within the core and branching points. The mesomorphic properties of the chirally homogeneous dendrimers GG4/MM4 and the corresponding chirally heterogeneous dendritic homologues GM4/MG4 were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Remarkably, the thermal profile and the mesophase structure of the four dendrimers appear to be significantly independent of the nature of the central chiral core. The outer chirality at the periphery significantly dominates the liquid crystalline properties.