Beyond Rigid Frameworks: A Dynamic 2D Supramolecular Organic Network of Luminescent Radicals in Water

ABSTRACT We report the design and synthesis of a water‐soluble luminescent radical, TTM‐3IMB, which spontaneously assembles with cucurbit[8]uril (CB[8]) into a well‐defined 2D honeycomb supramolecular organic framework (SOF) in aqueous solution. Unlike conventional covalent organic frameworks (COFs) or metal–organic frameworks (MOFs), the resulting SOF exhibits dynamic and reversible assembly behavior. Heating to 90°C triggers disassembly of the framework, while subsequent cooling to room temperature induces reassembly, as confirmed by temperature‐dependent fluorescence and EPR spectra. This reversible process enables modulation of spin–spin interactions and excited‐state dynamics within the framework. The SOF architecture not only enhances the photostability of TTM‐3IMB by four times but also increases its photoluminescence quantum efficiency from 2.0% to 5.0%. Multiscale characterization, including EPR, SEM, SAXS, and SQUID measurements, reveals an ordered honeycomb morphology and weak antiferromagnetic coupling among radical units. This work introduces a dynamic supramolecular strategy for constructing open‐shell 2D materials in water, offering new opportunities for tunable optoelectronic, magnetic, and bioresponsive applications.