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 Ce III -based octahedral cage with chloride ligands that boosts C( sp 3 ) − H photoactivation by marrying a Ce IV – 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-9 H -thioxanthen-9-one (TXO) for boosting PET via a pseudointramolecular pathway to oxidize Ce III – Cl to Ce IV – Cl and form TXO •– . The LMCT excitation of Ce IV – Cl is triggered to form Cl • that activates C( sp 3 ) − H via HAT, resulting in the regeneration of Ce III – Cl and the formation of an alkyl radical. TXO •– reduces the reaction intermediate, which transforms C( sp 3 ) − 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( sp 3 ) − H functionalization.