33617-43-5Relevant academic research and scientific papers
Synthesis, self-assembly, and characterization of supramolecular polymers from electroactive dendron rodcoil molecules
Messmore, Benjamin W.,Hulvat, James F.,Sone, Eli D.,Stupp, Samuel I.
, p. 14452 - 14458 (2007/10/03)
We report here the synthesis and self-assembly of a series of three molecules with dendron rodcoil architecture that contain conjugated segments of oligo(thiophene), oligo(phenylene-vinylene), and oligo(phenylene). Despite their structural differences, all three molecules yield similar self-assembled structures. Electron and atomic force microscopy reveals the self-assembly of the molecules into high aspect ratio ribbon-like nanostructures which at low concentrations induce gelation in nonpolar solvent. Self-assembly results in a blue-shifted absorption spectrum and a red-shifted, quenched fluorescence spectrum, indicating aggregation of the conjugated segments within the ribbon-like structures. The assembly of these molecules into one-dimensional nanostructures is a route to π-π stacked supramolecular polymers for organic electronic functions. In the oligo(thiophene) derivative, self-assembly leads to a 3 orders of magnitude increase in the conductivity of iodine-doped films due to self-assembly. We also found that electric field alignment of these supramolecular assemblies can be used to create arrays of self-assembled nanowires on a device substrate.
On the verge of axial chirality: Atroposelective synthesis of the AB-biaryl fragment of vancomycin
Bringmann, Gerhard,Menche, Dirk,Muehlbacher, Joerg,Reichert, Matthias,Saito, Nozomi,Pfeiffer, Steven S.,Lipshutz, Bruce H.
, p. 2833 - 2836 (2007/10/03)
(figure presented) Using the "lactone concept", differently substituted AB-biaryl fragments (P)-2 (R = Me, t-Bu) of vancomycin have been synthesized atroposelectively. Their otherwise configurational instability was remedied by inclusion of two chlorine atoms in the B ring to give (M)-29. Starting from a still configurationally unstable lactone-bridged precursor, we obtained this biaryl with high atroposelectivity (dr 94:6) by ring cleavage with dynamic kinetic diastereomeric resolution.
