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A novel biomimetic DNA analogue with fluorescence has been synthesized to generate functional supramolecular architectures. Experimental studies show that triaminopyrimidine nucleoside (2) undergoes a sterically controlled self-assembly into hydrogen-bonded linear tapes and hexameric rosettes. Self-association of the hydrogen-bonded triaminopyrimidine-cyanuric acid complex into elongated, rodlike nanostructures was shown by dynamic light scattering and transmission electron microscopy, suggesting hierarchical formation of higher-order, π-stacked assemblies. The hydrogen-bond self-assembly of the DNA analogue decreased the fluorescence of the nucleosides. This guest-induced fluorescence quenching can be used to develop DNA-hybridization probes. [MM.sup.+] molecular modelling and semi-empirical molecular orbital PM3 calculations (1) predicted the incorporation of triaminopyrimidine nucleoside into new types of artificial DNA strands and triplex formation with natural, complementary DNA strands containing thymine (1). Key words: hydrogen bond, self-assembly, DNA analogues. Dans le but de generer des architectures supramoleculaires fonctionnelles, on a synthetiser un nouvel analogue biomimetique de YARN fluorescent. Les etudes experimentales montrent que le nucleoside de la triaminopyrimidine (2) donne lieu a un autoassemblage sous controle cinetique qui conduit a des bandes lineaires on des rosettes hexameres reliees par liaisons hydrogenes. Faisant appel a la diffusion dynamique de la lumiere et a la microscopie dlectronique de transmission, on a pu ddmontrer que l'autoassociation du complexe triaminopyrimidine-acide cyanurique par des liaisons hydrogenes conduit a des nanostructures allongdes, en forme de baguettes, suggdrant qu' il y a une formation hidrarchique d'un ordee eleve d'assemblages par empilement π. L'autoassemblage par liaisons hydrogenes de l'analogue de l' AND diminue la fluorescence des nucleosides. Cette extinction de la fluorescence induite par l'hote pourrait etre utilisee pour developper des sondes d'hybridation de l'ADN. Des calculs de modelage moleculaire, [MM.sup.+], et des calculs d'orbitales moldculaires semi-empiriques, PM3 (1), permettent de prddire qu'il y aura incorporation du nucleoside de la triaminopyrimidine dans les nouveaux types de brins artificiels d'ADN et formation de triplex des brins naturels compldmentaires d'ADN contenant de la thymine (1). Mots-cles : liaison hydrogene, autoassemblage, analogues de l'ADN. [Traduit par la Redaction], Introduction Hierarchical assembly of low molecular weight building blocks has generated functional supramolecular architectures with high predictability. (1) Molecularly self-assembled photo-responsive systems were constructed by combining strong, directional, hydrogen bonds [...]

Ru(II) diimine complex is examined. The use of a ROMP monomer resulting in a dimer of this complex is described.

A new strategy to effect photoinduced control over molecular self-assembly is reported. This strategy uses the reversible trans-cis photoisomerization of a novel azobenzene system, where the trans- and cis-forms self-assemble into dramatically different higher-order structures. The trans-azobenzene form of this molecule associates into infinite hydrogen-bonded linear tapes, while the cis-azobenzene form undergoes hydrogen-bonded self-assembly into cyclic tetramers. This results in a second level of association, where the cis-hydrogen-bonded supramolecular cycles ultimately form long, rod-like aggregates through stacking interactions.