Photocatalytic technology is widely studied, while it comes with drawbacks such as low sunlight utilization efficiency and high carrier recombination rates. Herein, for the first time, we present two crystalline polyoxometalate (POM)-based metal−organic frameworks (POMOFs), {[Cd(DMF) 2 Ru(bpy) through assembling the photosensitizer [Ru-(bpy) 2 (H 2 dcbpy)]Cl 2 and POMs into a single framework. The assembly not only enhances light absorption in the visible light regime but also improves carrier separation efficiency; atop of that, both POMOFs demonstrate activities in the photocatalytic oxidative coupling of amines. Particularly, PMo-1 enables the quantitative completion of oxidative coupling of benzylamine reaction within 30 min (yield = 99.6%) with a high turnover frequency (TOF = 6631.6 h −1 ). To our knowledge, the PMo-1 catalyst outperforms any other photocatalysts previously reported in similar use cases where TOF values were usually obtained <2000 h −1 .

No abstract

The development of novel high-efficiency photocatalysts to solve the bottleneck problems of low efficiency and harsh conditions of organic oxidation reactions is of vital significance. In this paper, a novel hybrid polyoxometalate (POM) crystal, (C 2 H 8 N) 6 [SiW 11 CdO 39 ][Ru(bpy) 2 (dcbpy)]• DMF•5.5H 2 O (RuCd−SiW), was synthesized by combining the metalloligand [Ru(bpy) 2 (dcbpy)] with the oxidation catalyst POM. The introduction of the metalloligand extended the light absorption range of RuCd−SiW to the visible region, while electrochemical measurements demonstrated its potential as an excellent photocatalyst. Under visible light (λ > 400 nm) irradiation with O 2 as the sole oxidant, RuCd−SiW showed highly efficient photocatalytic activity for the selective oxidation of thioanisole to (methylsulfoxide)benzene with a yield of 99.5%, a turnover number of 497.5, and a turnover frequency of 103 h −1 . Particularly, the yield of (methylsulfoxide)benzene was still higher than 99% after five rounds of recycling, demonstrating its high stability and recyclability.

The development of solar-driven organic synthesis processes as an alternative to conventional thermo-catalytic technologies is of great research significance in academia and industry. Herein, we looked into the photoinduced Baeyer−Villiger oxidation of cyclohexanone based on the Mukaiyama method for the first time. We fabricated a crystalline polyoxometalate-based metal−organic framework photocatalyst, CR-SiW 12 , which represents the first example of trinuclear ruthenium clusters involved in the construction of polyoxometalate-based metal−organic frameworks. The cyclohexanone was efficiently converted to ε-caprolactone under visible light (>400 nm) irradiation with CR-SiW 12 as the catalyst, with a reaction turnover number and turnover frequency recorded as 941 and 274.5 h −1 , respectively, and the apparent quantum yield at 465 nm was measured to be 8.4%. Moreover, CR-SiW 12 exhibited high structural stability and reaction reusability where reaction yield remained high at 91.3% after five consecutive reaction cycles. This work offers a promising strategy for accomplishing Baeyer−Villiger oxidation reactions under green conditions.

No abstract