The results of the study presented here show a new example of the use of liquid crystals and the interactions involved in the mesomorphic state to build up complex molecular organizations. We have pursued a design strategy in which hydrogen bonding allows the combination of the pi-stacking tendency of melamine and the lateral interaction capability of V-shaped molecules, which has been extensively demonstrated through nematic, smectic, or columnar mesophases. This combination addresses the formation of columnar arrangements with inherent helical organization. In this work, nonmesomorphic as well as mesomorphic V-shaped acids, with a structure similar to banana liquid crystals, have been complexed to a 2,4,6-triamino-1,3,5-triazine derivative in a proportion 3 to 1, respectively. Hydrogen-bonded supramolecules whose formation and stability in solution have been proven by infrared and NMR techniques have been thus obtained. DOSY experiments have allowed us to assess in solution the presence of the complexes and their tetrameric composition. All the complexes display mesogenic ability, and their mesomorphic organization has been studied by X-ray diffraction and CD spectroscopy. Results allow us to propose a helical columnar model for the mesophase originated from a propeller-like conformation of the supramolecular complexes.

This tutorial review provides insight into helical columnar assemblies based on thermotropic as well as lyotropic liquid crystals on the basis of the structural characteristics that promote hierarchical self-organization. The structural features of molecular materials that can present helical organizations imply the action of different driving forces that include pi-interactions, hydrogen bonding or metal-coordination. In addition, columnar liquid crystals offer the possibility of combining these interactions towards the control of the geometry and orientation of the supramolecular organization leading to well-defined helical columnar assemblies.

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The synthesis of a novel core based on tris(triazolyl)triazine has been accomplished by a one-pot procedure that combines a 3-fold deprotection of alkyne groups and "click chemistry" of the aromatic alkyne and azide precursors. The procedure is straightforward for the preparation of functional materials for organic electronics. Indeed, compounds with low reduction potential are obtained. These compounds also show liquid crystalline behavior, displaying columnar mesophases at room temperature, and are luminescent in the visible region both in solution and in thin films.