Merging Photoredox and Organometallic Catalysts in a Metal-Organic Framework Significantly Boosts Photocatalytic Activities

Abstract

Metal-organic frameworks (MOFs) have been extensively used for single-site catalysis and light harvesting, but their application in multicomponent photocatalysis is unexplored. We report here the successful incorporation of an Ir^III photoredox catalyst and a Ni^II cross-coupling catalyst into a stable Zr₁₂ MOF, Zr₁₂ -Ir-Ni, to efficiently catalyze C-S bond formation between various aryl iodides and thiols. The proximity of the Ir^III and Ni^II catalytic components to each other (ca. 0.6 nm) in Zr₁₂ -Ir-Ni greatly facilitates electron and thiol radical transfers from Ir to Ni centers to reach a turnover number of 38 500, an order of magnitude higher than that of its homogeneous counterpart. This work highlights the opportunity in merging photoredox and organometallic catalysts in MOFs to effect challenging organic transformations.

Keywords: heterogeneous catalysis; metal-organic frameworks; nickel; photochemistry; sulfides.