Sub‐Stoichiometric Supramolecular Co‐Assembly Strategy Enabling Efficient Chirality Transfer and CPL Amplification

Abstract

ABSTRACT Chirality transfer enables molecular asymmetry to propagate from discrete building blocks into hierarchical assemblies, providing a fundamental framework for engineering functional nanostructures. However, conventional supramolecular co‐assembly typically necessitates stoichiometric or excess guest loading to achieve effective chirality transfer, a requirement that often compromises structural fidelity and chiroptical efficiency due to inefficient stereochemical communication. Here, we report a sub‐stoichiometric co‐assembly strategy wherein trace amounts of an achiral modulator (berberine, BBR) cooperatively intercalate within a chiral supramolecular framework (LPF/DPF; left‐/right‐handed phenylalanine‐based gelators) to induce potent chiroptical amplification. We demonstrate that a minimal guest‐to‐host mole ratio of 0.2 is sufficient to capture and amplify host chirality, yielding luminescence dissymmetry factors (| g lum | ≈ 0.08) an order of magnitude higher than those produced by stoichiometric equivalents. Mechanistic investigations reveal that sparse intercalation at this sub‐stoichiometric threshold preserves the underlying hydrogen‐bonded network while enforcing a precise helical registry through synergistic π–π and electrostatic interactions that ensures thermodynamic stability (Δ G °). While stoichiometric excess results in kinetically trapped, non‐helical aggregates, this sub‐stoichiometric control establishes a robust design principle for translating molecular‐scale interactions into high‐performance chiroptical materials with minimal guest loading.