Lacunary Evolution of Molybdenum Blue Clusters for Efficient and Sustainable Photocatalytic Chemodivergent C─C...

High-nuclearity molybdenum blue (MB) clusters with regular lacunary variation are of great importance for polyoxometalate structure evolution and photocatalytic application study, but their synthesis still remains a huge challenge. Herein, we successfully synthesized a series of high-nuclearity MB clusters, S₂Mo₆₂, SMo₅₃W₇, Mo₅₀W₈, and Mo₄₄W₈, which exhibit regular lacunary variation. More importantly, such structural variation endows these MB clusters with distinct Lewis acidity and redox properties. Consequently, when employed as heterogeneous photocatalysts for the chemodivergent C─C coupling reactions between 1,3-diketones and alkenes, the hexa-lacunary Mo₅₀W₈ and Mo₄₄W₈ with more Lewis acid sites can achieve a 93% 1,5-diketone yield within 12 h, while parent S₂Mo₆₂ with superior oxygen activation can achieve a 99% 1,4-diketone yield within 3 h. Furthermore, Mo₅₀W₈ enables gram-scale and sunlight driven synthesis of diverse 1,5-diketone, and maintains long-term cycling stability over 370 h (16 cycles). This work represents the first report of high-nuclearity MB clusters with regular lacunary variation, and extends their application to sunlight driven photocatalytic C─C coupling reaction, highlighting the innovative research of MB clusters.