Functionalized Thorium-Based Metal-Organic Frameworks for the Photocatalytic Oxidation of 1, 5-Dihydroxynaphthalene.

It is still a challenging task to rationally design metal-organic framework (MOF) crystal catalysts with excellent light absorption and charge transfer for efficient photocatalytic reactions. In this work, the hexanuclear thorium clusters, porphyrin derivative ligands, and linear carboxylic acid ligands were assemed into Th-based metal-organic frameworks (Th-TCPP, Th-Co-TCPP, and Th-Ni-TCPP) by the mixed ligand method. The three prepared MOF crystals were applied in the photocatalytic oxidation of 1, 5-dihydroxynaphthalene (1, 5-DHN) for the synthesis of juglone. Among them, Th-TCPP exhibited optimum photodynamic activity for production of reactive oxygen species. Under lillumination, Th-TCPP resulted in photochemical reaction conversion rate up to 95 % for 9, 10-diphenylanthracene (DPA) and 54.5 % for 1, 5-DHN. The good catalytic effect was attributed to the large conjugate system of porphyrin and the enhanced photosensitivity of bipyridine.