Dual-catalytic architectures accommodated by titanium-oxo clusters boosting visible-light-driven C–N cross-coupling <i>via</i> intramolecular electron transfer

Developing dual-catalytic architectures integrating photoactive and transition metal sites holds significant potential for light-driven cross-coupling reactions. This study presents a novel strategy to create synergistic dual-catalytic architectures based on surface engineering of Ti₆-oxo clusters for efficient photocatalytic formation of C-N bonds. Ti₆-oxo clusters are precisely decorated with bipyridine ligands through competitive coordination, followed by the anchoring of iridium photo-sensitizers and nickel catalytic centers to the electron-rich nitrogen sites. The obtained Ni-Ir/Ti₆-Bpca exhibits significantly enhanced charge transfer efficiency <i>via</i> an intramolecular electron transfer mechanism. This integrated design not only boosted catalytic activity across diverse substrates but also suppressed metal site leaching and nickel black formation through the coordination protection effect. The Ni-Ir/Ti₆-Bpca system achieved remarkable functional group tolerance with reduced catalyst loading under visible light irradiation (blue light, <i>λ</i> _max = 430 nm). By demonstrating enhanced electron transfer kinetics and operational stability, this work opens up vast opportunities for titanium-oxo clusters in photocatalysis and provides a blueprint for developing sustainable cross-coupling methodologies.