Anomalous Chiral Transfer: Supramolecular Polymerization in a Chiral Medium of a Mesogenic Molecule. Issue 10 (5th April 2022) - Zhang, Xu‐Jie
Abstract: Here, we report a medium‐to‐polymer anomalous chiral transfer in the supramolecular polymerization of a tetraphenylporphyrin‐based achiral hydrogen‐bonding monomer (TPP ) in a chiral medium of 5‐cyanobiphenyl CB* . A mixture of TPP in ( R )‐CB* ([TPP ]=7.7 mol %) at 40 °C gave a columnar oblique LC mesophase, where the individual columns were composed of an optically active helical supramolecular polymer of TPP as a consequence of a successful medium‐to‐polymer chiral transfer. Meanwhile, upon dilution of CB* with achiral 5‐cyanobiphenyl CB, the optical activity of the system showed an anomalous bell‐shaped dependency on the composition of CB* /CB, where the g abs value of 0.049 at CB* /CB =50/50 was 6.0 times larger than the g abs value of CB* alone. Such anomalous chiroptical amplification in CD is most likely due to a change in the stacking geometry of TPP in the oblique columnar LC upon lateral compression. Abstract : A medium‐to‐polymer anomalous chiral transfer in the supramolecular polymerization of an achiral monomer (TPP ) in a chiral medium of CB* is reported. The optical activity was maximized when half of CB* was replaced with achiral CB where the g abs value of 0.049 was 6.0 times larger than the g abs value of CB* alone, as a consequence of inter‐polymer interaction.