Artificial Light-Harvesting Metallacycle System with Sequential Energy Transfer for Photochemical Catalysis

Highly efficient light-harvesting systems with the sequential energy transfer process are significant for utilizing solar energy in photosynthesis. Herein, we report a quadrilateral platinum­(II) metallacycle containing tetraphenyl­ethylene (M1) as a light-harvesting platform. The M1 assembly serves as an ideal donor because of the aggregation-induced emission (AIE) effect, realizing two-step sequential energy transfer from the M1 assembly to eosin Y (ESY) and then to sulforhodamine (SR101) with high efficiency. ESY was used as a bridge in a relay mode during this process. To better mimic natural photosynthesis, the M1–ESY–SR101 system was utilized as photochemical catalysis for alkylation of C–H bonds in aqueous solution, showing enhanced catalytic activity as compared with the M1–ESY system or ESY/SR101 alone.