Energy transfer-mediated multiphoton synergistic excitation for selective C(sp3)–H functionalization with coordination polymer

Abstract Activation and selective oxidation of inert C( sp 3 )–H bonds remain one of the most challenging tasks in current synthetic chemistry due to the inherent inertness of C( sp 3 )–H bonds. In this study, inspired by natural monooxygenases, we developed a coordination polymer with naphthalenediimide (NDI)-based ligands and binuclear iron nodes. The mixed-valence Fe III Fe II species and chlorine radicals (Cl • ) are generated via ligand-to-metal charge transfer (LMCT) between Fe III and chlorine ions. These Cl • radicals abstract a hydrogen atom from the inert C( sp 3 )–H bond of alkanes via hydrogen atom transfer (HAT). In addition, NDI converts oxygen to 1 O 2 via energy transfer (EnT), which then coordinates to Fe II , forming an Fe IV = O intermediate for the selective oxidation of C( sp 3 )–H bonds. This synthetic platform, which combines photoinduced EnT, LMCT and HAT, provides a EnT-mediated parallel multiphoton excitation strategy with kinetic synergy effect for selective C( sp 3 )–H oxidation under mild conditions and a blueprint for designing coordination polymer-based photocatalysts for C( sp 3 )–H bond oxidation.