Chiral Competition Reflected by Circularly Polarized Luminescence Signal Inversion in Supramolecular Assembly of...

Chiral competition between carbohydrates and amino acids is crucial for understanding homochirality emergence in biological systems. In this study, the chiral competitive effect between carbohydrates and amino acids through the host-guest complex formation was investigated by employing amino acid modified pyrene derivatives and naturally occurring γ-cyclodextrin (γ-CD) as chiral sources, the circularly polarized luminance (CPL) as indicator. Supramolecular complexes of achiral 1-pyrenebutyric acid and L-amino acid-pyrene derivatives with γ-CD exhibited positive CPL signals, with chirality derived from γ-CD's stereochirality. In contrast, supramolecular complexes formed by D-amino acid-pyrene derivatives with γ-CD showed a negative CPL signal, reflecting chiral competition between D-amino acids and D-glucose in γ-CD. The observed CPL signal inversion confirmed that the amino acids stood out as the dominant chiral source in chiral competition with carbohydrates. Mechanism exploration showed that the depth of insertion and stacking arrangement of the guest molecules within the γ-CD cavity played an essential role for the CPL inversion. Interestingly, chiral competition only occurred between D-amino acids and D-carbohydrates, while cooperation was observed between L-amino acids and D-carbohydrates, which were consistent with the natural chirality bias. This work provides new insights into homochirality emergence and the design of functional chiral materials.