Sequential Coordination‐Covalent Construction of Designable and Photoredox Microporous Gels Integrating Well‐Defined Titanium‐Oxo Clusters

ABSTRACT Titanium‐oxo clusters (TOCs) are attractive in photocatalysis due to their designable structures and photoredox properties. The use of TOCs as intact building blocks to construct porous matter with tunable physical states is essential to maximize their properties for practical applications, but challenging due to the complex Ti─O condensation during synthesis that easily changes the original TOC structures. Herein, we demonstrate a sequential synthetic strategy to covalently couple preformed TOC units with well‐defined coordinative structures into microporous gels. The covalent assembling is achieved by incorporating functional vinyl groups into the surface of TOCs as reactive sites, which can undergo a light‐/heat‐triggered vinyl polymerization to gelate TOCs without interrupting their structures. The TOC topology and the number of surface vinyl groups can be predesigned, together with the capability of integrating diverse monomers for co‐polymerization, allowing the gel structures and properties to be well‐tuned. We demonstrate the utility of the TOC‐based gels as quasi‐homogeneous photoreactors for dehalogenation, achieving remarkable isolated yields, gram‐scale productivity, and recyclability.