Hierarchical Supramolecular Nanostructures of Cyclic Hydrogen-Bonding Catemers in Dibenzo[ a , c ]phenazinecarboxylic Acid Discotic Liquid Crystals

The hydrogen-bonding motif of dibenzo[a,c]phenazinecar-boxylic acids can be enforced to form hierarchical cyclic hydrogen -bonded trimers for creating a 3D Colh assembly at the mesophase, as demonstrated by X-ray diffraction. Scanning tunneling microscopy was used to characterize the formation of the cyclic trimers. Atomic force microscopy revealed the formation of nanopillars on a hydrophilized sil-ica surface upon annealing from isotropic to room temperature.