RESUMEN
We report the helix-sense-selective memory polymerization (HSMP) of achiral biphenylylacetylenes bearing carboxy and amino pendant groups in the presence of basic and acidic chiral guests in water, respectively. The HSMP proceeds in a highly helix-sense-selective manner driven by noncovalent chiral ionic interactions between the monomers and guests under kinetic control, producing the one-handed helical polymers with a static memory of helicity in one-pot during the polymerization in a very short time, accompanied by amplification of asymmetry. The carboxy-bound helicity-memorized polymer self-assembles into a cholesteric liquid crystal in concentrated water, in which a variety of basic achiral fluorophores further co-assembles to form supramolecular helical aggregates that exhibit an induced circularly polarized luminescence in a color tunable manner.
RESUMEN
A series of poly(biarylylacetylene)s (PBAs) bearing axially-chiral (S)-and (R)-pyridyl-N-oxide residues with a methoxy, propoxy, or acetyloxy substituent at the 3-position of the biaryl units was synthesized. All the PBAs formed a preferred-handed helix, while the helical sense preference was varied depending on the substituents despite the same twist-sense of the biaryl units. Among them, the propoxy-bound helical PBA showed an exceptionally high chiral recognition ability as a chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC) and efficiently resolved not only various chiral aromatic alcohols, but also a variety of chiral aliphatic alcohols; the latter still remains difficult to resolve by commercially-available CSPs in HPLC. Such practically-useful both handed helical PBA-based CSPs can be produced from the racemic PBA composed of fully racemic monomer units through deracemization of the biaryl units with a chiral alcohol.
