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

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.