86996-83-0Relevant 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
supporting information; experimental part, p. 1473 - 1484 (2011/04/15)
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.
Modulating large-area self-assembly at the solid-liquid interface by pH-mediated conformational switching
Piot, Luc,Meudtner, Robert M.,Malah, Tamer El,Hecht, Stefan,Samori, Paolo
supporting information; experimental part, p. 4788 - 4792 (2009/12/05)
The two-dimensional ordering of molecules adsorbed on surfaces at the solid-liquid interface that are capable to undergo large conformational changes upon the application of an external chemical stimulus was investigated. Large-area self-assembly at the solid-liquid interface was modulated using pH-mediated conformational switching. Scanning tunneling microscopy (STM) visualization was attempted for the first time to examine and visualize large conformational changes of a responsive molecular building block resulting in its altered self-assemble behavior at the solid-liquid interface. It was observed that protonation can work effectively to overcome the repulsive interaction between certain 2,6-bis (1-aryl-1,2,3-triazol-4-yl) pyridine (BTP) molecules and also in the formation of an extended conformation on a HOPG surface. The method has encouraged the efforts towards development of reversible pH triggered switches at the solid-liquid interface.
