An Efficient Artificial Light‐Harvesting System Constructed Based on Host–Guest Interactions in Aqueous Environment for Photocatalytic Dehalogenation Reactions

In this study, a strategy for constructing an artificial light-harvesting system (LHS) in an aqueous environment through host-guest interactions is proposed. An amphiphilic anthracene derivative (MVPA), functionalized with two methylated vinylpyridine arms, was designed and synthesized. Upon sequential addition of cucurbit[6]uril (CB[6]) and cucurbit[8]uril (CB[8]), MVPA underwent supramolecular self-assembly to form well-defined polymeric structures exhibiting enhanced fluorescence properties and distinct spherical morphologies, thereby serving as efficient energy donors (MVPA-CB[6] and MVPA-CB[8]). Subsequently, the fluorescent dye Cy5 was introduced into the aqueous solutions of MVPA-CB[6] and MVPA-CB[8] as an energy acceptor. The resulting artificial LHSs demonstrated highly efficient Förster resonance energy transfer from the donor to the acceptor, with an energy transfer efficiency of 81% for the MVPA-CB[8]-Cy5 system. To harness the harvested energy further, MVPA-CB[6] and MVPA-CB[8] assemblies were employed as photocatalysts for dehalogenation reactions in aqueous solutions. At 0.12 mol%, the reaction yields improved to 51% and 68%, respectively, indicating the effective conversion of solar energy into chemical energy. This work not only presents a new approach for constructing high-performance aqueous artificial LHSs but also demonstrates their practical application in photocatalytic transformations, specifically the dehalogenation of α-bromoacetophenone, thus highlighting their potential in mimicking natural photosynthetic processes.