Helical supramolecular polymers with rationally designed binding sites for chiral guest recognition

Abstract

Since various helical supramolecular polymers became available, their application to molecular chirality recognition have been anticipated but not extensively studied. So far, only a few examples of chiral reactions have been reported, but none for chiral separation. Here, we report the application of a helical supramolecular polymer to the enantio-separation of chiral guest molecules. The monomer of this supramolecular polymer is the salt-pair of a dendritic carboxylic acid with an enantiopure amino alcohol. In an apolar solvent, this salt-pair stacks via hydrogen bonds to form a helical polymer. In conjunction with this carboxylic acid, various amino alcohols afford supramolecular polymers, whose helical handedness is determined by the stereochemistry of the amino alcohols. When two salts with the same chirality are mixed, they undergo copolymerization, while those with opposite chirality do not. Owing to this stereoselective copolymerizability, the helical supramolecular polymer could bias the enantiomeric composition of chiral amino alcohols.

Controlling the length of porphyrin supramolecular polymers via coupled equilibria and dilution-induced supramolecular polymerization

“…Enantioselective interactions can reduce the level of complexity in multi-component systems by introducing specificity in the interactions of the components, which can be helpful to isolate effects in the aggregation pathways. Chiral recognition and exchange of chiral information are crucial in biological systems, but also in chemical catalysis 23 – 26 , host-guest complexes 27 – 29 and supramolecular systems 30 – 35 . In the supramolecular polymerizations of homochiral monomers, M- or P- helical fibers are formed.…”

Self-sorting assembly of artificial building blocks

“…[66][67][68][69] Chirality also may affect the rotation of chiral molecules with hydrogen bonds or the stacking of aromatic molecules. 70 George and co-workers reported the chiral recognition of trans-1,2-bis(amido)cyclohexane modified by a pair of naphthalenediimide (NDI) groups. 71 The NDI groups were modified with ethoxy groups as the donor or N-isopropyl amine groups as the acceptor for monitoring their self-assembly behaviour.…”

Mechanism of diastereoisomer-induced chirality of BiOBr

“…Chiral molecule-driven asymmetric structures are ubiquitous in biological organisms 1–3 and have been artificially mimicked to fabricate chiral materials, including organics, 4–9 inorganics, 10–16 and organic–inorganic hybrids. 17–19 The great potential of assembled chiral inorganics in optics, electricity, magnetism, biology, and chemistry has attracted tremendous interest in the chiral molecule-driven assembly of chiral inorganic nanostructures.…”