Ru Metalloligands Participate in the Construction of POM@MOF for Enhancing the Visible Photoinduced Baeyer-Villiger Oxidation Reaction

Directed synthesis of high-efficiency visible photoinduced Baeyer-Villiger oxidation catalysts is of primary significance. Here, the isopolymolybdate anion [beta-Mo8O26](4-) is for the first time encapsulated with the photosensitive metalloligand [Ru(bpy)(2)(H(2)dcbpy)](2+) (bpy = 2,2 '-bipyridine; H(2)dcbpy = 2,2 '-bipyridine-5,5 '-dicarboxylic acid) to synthesize polyoxometalate@metal-organic frameworks, {(CdDMF)(2)[Ru(bpy)(2)(dcbpy)](3)([beta-Mo8O26])}center dot 5DMF (Ru-Mo-8). The composite photocatalyst Ru-Mo-8 not only has a light absorption of 700 nm but also shortens the photogenerated electron transfer distances and accelerates charge and proton transfer. Ru-Mo-8 can perform the Baeyer-Villiger oxidation with high selectivity and up to 96.7% yield under visible light (lambda > 400 nm) irradiation. The turnover number and turnover frequency of the reaction were computed to be 967 and 548 h(-1), respectively, and the apparent quantum yield was 6.84% by 425 nm. Simultaneously, the radical mechanism of Baeyer-Villiger oxidation of Ru-Mo-8 in the O-2/benzaldehyde system under visible light (lambda > 400 nm) irradiation was proposed.