Dye-Binding Metal–Organic Cage for Highly Efficient Multiphoton Activation of C(sp3)–H Bonds

Enzymes facilitate chemical conversions through the integrated activity of multicomponents, but the aggregation of multiactive sites with molecular containers to emulate enzymatic conversion remains challenging. Herein, we report a new CeIII-based octahedral cage with chloride ligands that boosts C­(sp3)−H photoactivation by marrying a CeIV–Cl photocatalyst and photoredox catalyst to integrate photoinduced electron transfer (PET), ligand-to-metal charge transfer (LMCT), and hydrogen-atom transfer (HAT) events through multiphoton excitation. This molecular cage binds 2-chloro-9H-thioxanthen-9-one (TXO) for boosting PET via a pseudointramolecular pathway to oxidize CeIII–Cl to CeIV–Cl and form TXO•–. The LMCT excitation of CeIV–Cl is triggered to form Cl• that activates C­(sp3)−H via HAT, resulting in the regeneration of CeIII–Cl and the formation of an alkyl radical. TXO•– reduces the reaction intermediate, which transforms C­(sp3)−H and facilitates recovery of TXO for subsequent recycling. This approach offers a feasible strategy for creating highly electrophilic radicals resembling enzymes and demonstrates their potential for C­(sp3)−H functionalization.