Cluster-Enabled Control of Single-Electron Photoredox Catalysis in Reticular Frameworks

The development of sustainable catalytic strategies for the formation of carbon–carbon bonds is central to the future of synthetic chemistry. Photoredox catalysis has emerged as a powerful alternative to traditional redox chemistry, replacing harsh conditions and stoichiometric reagents with visible light and single-electron transfer (SET) processes. However, most current systems rely on homogeneous catalysts containing iridium or ruthenium complexes, which are expensive, scarce, and difficult to recover. The development of robust, recyclable, and earth-abundant platforms that can operate under photoredox conditions while maintaining high efficiency and selectivity remains a central goal in the field. This work presents a new strategy for achieving photoredox reactivity using heterometallic clusters embedded in reticular frameworks. By integrating titanium and iron into a redox-active metal–oxo cluster, we designed a pristine MOF capable of promoting light-driven single-electron transfer chemistry without the need for any additives, external photosensitizers, or noble metals. The ability to fine-tune the electronic properties of the cluster through metal selection opens the door to a new generation of porous, crystalline materials for photoredox transformations involving the formation of new C–X bonds. In the long term, such systems could support the development of flow-compatible, heterogeneous, and recyclable catalysts for pharmaceutical synthesis, fine chemicals, or sustainable feedstock conversion. Beyond catalysis, this cluster-based approach also provides a design principle for building functional materials that integrate light absorption, charge separation, and redox reactivity in a single solid-state platform.