Structurally Enhanced Colloidal Molecules via Carbene-Mediated Covalent C─H Insertion Crosslinking

Achieving high structural stability of colloidal molecules (CMs) is crucial for their implementation in constructing functional materials and devices, but remains challenging. Here, we develop a universal strategy based on nonspecific covalent crosslinking of surface ligands for markedly enhancing the stability of CMs while fully preserving their structural integrity and physicochemical properties. The resulting crosslinked CMs exhibit exceptional resistance to alkaline conditions (up to pH = 12), high salt concentrations (150 mM), external electric fields, and hydrogen-bonding perturbations. These achievements stem from the rational design of the crosslinker 3G, which involves shielding aliphatic C-H bonds, extending the spacing between reactive sites, and increasing the number of active sites, thereby enabling efficient bridging of adjacent particles within CMs under mild reaction conditions. The nonspecific nature of this 3G-based approach affords broad applicability, setting it apart from conventional stabilization methods that require purpose-designed crosslinkable ligands. This stabilization approach can be readily extended to CMs with complex three-dimensional architectures, expanding opportunities for exploiting diverse CM libraries across a wide range of applications.