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.

The creation of cyclodextrin patterns on a fluorescent reporter surface by microcontact printing provides a versatile orthogonal surface modification method. The alkyne-beta-cyclodextrin surface is prepared through a "click" reaction on alkyne-terminated coumarin monolayers. The resulting alkyne-beta-cyclodextrin surface can be functionalized through supramolecular microcontact printing on cyclodextrin host patterns and by reactive microcontact printing-induced click chemistry on the alkyne-terminated patterns. The orthogonal covalent and supramolecular "host-guest" functionalization of the surface, and its specificity as well as selectivity, is demonstrated by sequential and one-step printing procedures.

The use of complementary 2,4,6-triarylamino-1,3,5-triazines and benzoic acids has allowed the preparation of a variety of disklike supramolecules with different substitution patterns around an H-bonded aromatic core. Most of the complexes obtained show columnar mesomorphism promoted by an efficient columnar packing of the aromatic cores surrounded by a minimum of six peripheral tails. The steric requeriments for the appearance of mesomorphic behavior in these supramolecular complexes have been established by X-ray diffraction studies and density calculations based on the parameters of the liquid crystalline organization.

The synthesis and photopolymerization of various liquid crystalline dioxetanes is described. The effects of the spacer length, structure of the mesogenic group and oxetane group on the liquid crystalline properties, polymerization behaviour and optical properties (birefringence) of the oriented and crosslinked network formed in photo-polymerization are discussed. Thermally stable films with birefringence values up to 0.13 can be formed from these materials. The dioxetanes show significantly lower polymerization shrinkage than do structurally related diacrylates.

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The work described here concerns a challenge of general interest in supramolecular chemistry: the achievement of chiral helical organizations with controlled structures. This work provides a strategy to obtain supramolecular polymers in which a chiral helical conformation has been induced by a noncovalent association, that is, through hydrogen bonding. Polycatenar 2,4,6-triarylamino-1,3,5-triazines, which organize into columnar mesophases and are susceptible to H-bonding interactions, were chosen as a starting point to build up the chiral supramolecular structure. The stacking of these mesogens has been forced to wind in a helical way by means of H-bond association with (R)-3-methyladipic acid, within the mesophase. The optically active columnar organization has been studied in depth by optical microscopy, differential scanning calorimetry (DSC), X-ray diffraction, and circular dichroism. Formation of stable complexes between the triazine units and (R)-3-methyladipic acid has also been investigated by means of NMR diffusion-ordered spectroscopy (DOSY) experiments in chloroform.

The possibility of achieving chiral helical superstructures in the columnar mesophase of H-bonded complexes of 2,4,6-triarylamino-1,3,5-triazines and chiral benzoic acids is pursued in this work. A series of heterodimeric complexes have been prepared and their mesomorphic states studied by polarized optical microscopy, differential scanning calorimetry, X-ray diffraction, and circular dichroism. It is concluded that steric requirements strongly influence the mesomorphism of these H-bonded complexes. Hence, well-defined columnar arrangements, characterized by high transition enthalpies and a large number of X-ray diffraction rings, are exhibited by complexes with a given number of peripheral tails and a steric compromise between the sizes of the triazine and the acid partners. Optical activity derived from a chiral columnar organization within the mesophase appears for these well-defined hexagonal columnar mesophases.

The present work describes a series of H-bonded complexes consisting of a melamine derivative and polycatenar acids that show columnar liquid crystalline behaviour. Chirality has been transferred from the molecular blocks (either the acids, A3* and A4*, or the melamine, T2*) to the columnar organization. Particular effort and attention has been paid to structural characterization by NMR techniques [1D NMR spectroscopy and diffusion-ordered spectroscopy (DOSY) experiments] of the complexes in solution. The mesomorphic arrangements of all the complexes have been studied by polarizing optical microscopy (POM), differential scanning microscopy (DSC) and powder X-ray diffraction. The chiral nature of the supramolecular organization in the mesophase has been confirmed by circular dichroism spectroscopy on neat samples over a range of temperatures.