Olefin Photooxidation within Rhenium and Ruthenium-Doped Nanoporous Metal–Organic Frameworks

Abstract

Metal–organic frameworks (MOFs) are nanoporous materials with exceptional stability, tunability, and high surface area, making them remarkable candidates for heterogeneous catalysis. UiO-67, a zirconium-based MOF, has been shown to be a good host for catalytic reactions, but is limited by poor photoactivity. Doping UiO-67 with photoactive molecules, such as ruthenium and rhenium complexes, can promote diverse photocatalytic transformations. This study explores Ru-UiO-67 and Re-UiO-67 (UiO-67 MOFs doped with ruthenium and rhenium complexes, respectively) as photocatalysts for the oxidation of olefins with molecular oxygen under visible light. Here, cyclohexene was employed as a model substrate to characterize and optimize the photocatalytic system, thereby expanding the use of these photoactive nanoporous MOFs to aerobic olefin oxidation. We further demonstrate that the photooxidation selectivity can be tuned by changing the reaction parameters. The experimental results show that the MOFs efficiently generate singlet oxygen and superoxide species, offering a sustainable, heterogeneous alternative to conventional photocatalysts. Beyond demonstrating efficient olefin photooxidation, this work provides key insights into the relationship between the MOF structure, photophysical properties, and photocatalytic activity. By leveraging the inherent tunability of MOFs, this research lays the groundwork for future innovations in photocatalysis, enabling the design of advanced nanomaterials for sustainable chemical transformations.