ritopic tris-calixarene TC4-possessing three divergent cavities linked to a tris-aminophenylamine core-forms, in the presence of tetra-anionic Cu(ii) porphyrins CuTPPS or a combination of different metallo-porphyrins (CuTPPS, NiTPPS and MnTPPS), discrete 3:1 porphyrin/tris-calixarene complexes. The 3:1-(CuTPPS/TC4) complex in particular is shown to be a key building block for the assembly of supramolecular architectures of increasing complexity. Directional (radial vs. stacked) self-assembly of these nanostructures was achieved by alternate addition of selected hetero-components in a programmed fashion. Addition of TC4 and CuTPPS, in turn, leads to a radial growth of the assembly, whereas, addition of single-cavity calixarene C4 stoppers followed by a CuTPPS topping, promotes a stacked growth. In the latter case, the use of chiral (R)- or (S)-C4 stoppers is seen to induce chirality in the whole assembly. Circular dichroism data ultimately suggest that porphyrin molecules located above/below the 3:1 core complex act as a "molecular glue", by making the interaction between chiral calixarenes (R)- or (S)-C4 and the achiral 3:1-(CuTPPS/TC4) complex stronger.
|Titolo:||Porphyrin stack as an efficient glue to induce Chirality in hetero-component calyxarene-porphyrin assemblies|
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||1.1 Articolo in rivista|