BINOL-Based Zirconium Metal–Organic Cages: Self-Assembly, Guest Complexation, Aggregation-Induced Emission, and Circularly Polarized Luminescence

TL;DR

Researchers created chiral metal cages that emit polarized light, which could improve optical devices and sensing technologies.

Contribution

A new chiral metal–organic cage is developed that enhances circularly polarized luminescence through self-assembly and guest complexation.

Findings

The cages show high affinity for anionic guests via electrostatic and hydrogen-bonding interactions.

The system achieves a luminescence dissymmetry factor (|glum|) of 1.2 × 10−3, a five-fold improvement over the unassembled ligand.

The rigid cage framework enhances aggregation-induced emission and acts as an effective chiral amplifier.

Abstract

The development of nanoscale chiral materials with enhanced optical properties holds significant promise for advancing technologies in light-emitting devices and enantioselective sensing. Here, we report the self-assembly of chiral metal–organic cages from an axially chiral, AIE-active binaphthyl dicarboxylate ligand. This supramolecular architecture functions as a multifunctional platform, demonstrating a high affinity for anionic guests through synergistic electrostatic and hydrogen-bonding interactions. The rigid cage framework not only enhances the ligand’s intrinsic aggregation-induced emission (AIE) but also serves as a highly effective chiral amplifier. Notably, MOCs significantly boost the circularly polarized luminescence (CPL), achieving a luminescence dissymmetry factor (|glum|) of 1.2 × 10−3. This value represents an approximately five-fold enhancement over that of the unassembled ligand. The photophysical properties of this chiral supramolecular system provide a strategic blueprint for designing next-generation optical nanomaterials.

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