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.

Tianyi Yang

PhD Candidate (2021)

She is very casual most of the time, and occasionally very obsessed with something.

Haoyuan Qu

PhD Candidate (2022)

This student is a genuine Changchun native, friendly and approachable.

Guanglu Wu

Professor

Research interests: multi-component functional assemblies, noncovalent dimerization, supramolecular catalysis, and smart soft matter