680988-06-1Relevant articles and documents
Designing Structural Motifs for Clickamers: Exploiting the 1,2,3-Triazole Moiety to Generate Conformationally Restricted Molecular Architectures
Zornik, Denise,Meudtner, Robert M.,Ela Malah, Tamer,Thiele, Christina M.,Hecht, Stefan
, p. 1473 - 1484 (2011)
Noncovalent interactions, especially hydrogen-bonding interactions as well as electrostatic forces, confined within one macromolecule are the key to designing foldamers that adopt well-defined conformations in solution. In the context of significant recent activities in the area of triazole-connected foldamers, so-called clickamers, we present a fundamental study that compares various model compounds that bear adjacent N-, O-, or F-heteroatom substituents. The interplay of attractive and repulsive interactions leads to rotational constraints around the single bonds attached to both the 1- and 4-positions of the 1,2,3-triazole moiety and should therefore be able to induce well-defined conformational preferences in higher oligomers and polymers, that is, foldamers. Various compounds were synthesized and characterized with regard to their preferred conformations in all three aggregation statesa-that is, in the gas phase, in solution as well as in the solid statea-by employing DFT calculations, NMR spectroscopic experiments, and X-ray crystallography, respectively. On the basis of the thus-obtained general understanding of the conformational behavior of the individual connection motifs, heterostructures were prepared from different motifs without affecting their distinct folding characteristics. Therefore, this work provides a kind of foldamer construction kit, which should enable the design of various clickamers with specific shape and incorporated functionality. A foldamer construction kit: Various heterostructures "clicked" together by structure-directing triazole moieties were investigated with regard to their conformational behavior. Different heteroatoms (X; see graphic) can be used to bias the conformation around the N(1)- and C(4)-connecting single bonds of the triazoles based on tunable noncovalent interactions.
