Electron Transfer Mediator–Enabled Modular Control of ¹ O ₂ and O ₂ ^•– Generation in Porphyrin Supramolecular Frameworks for Selective Photosynthesis

Abstract

ABSTRACT The inherent preference of classical type II photosensitizers for generating singlet oxygen ( 1 O 2 ) via energy transfer presents a key challenge in developing type I systems capable of producing superoxide radicals (O 2 •– ) through electron transfer. Herein, we report a porphyrin‐based supramolecular organic framework (SOF, TPP‐BPY‐CB[8]) assembled via host–guest interactions with cucurbit[8]uril (CB[8]), which achieves a significantly enhanced 1 O 2 quantum yield (94.04%) compared to the monomeric unit TPP‐BPY (74.52%). To overcome the energy transfer‐dominated reactive oxygen species (ROS) pathway, a series of electron transfer mediators were introduced to modulate the excited‐state dynamics, resulting in BQ@TPP‐BPY‐CB[8] that effectively switches the ROS pathway from type II to type I. This mediator‐driven modulation not only enables O 2 •– production under hypoxic conditions but also expands the functional diversity of the SOF system. The two ROS pathways are selectively leveraged in photocatalytic applications: TPP‐BPY‐CB[8] excels in 1 O 2 ‐mediated oxidation of organophosphorus compounds, while BQ@TPP‐BPY‐CB[8] facilitates highly efficient thiol‐ene cross‐coupling via O 2 •– promotion. This work presents a robust strategy for tailoring ROS generation in supramolecular photocatalysis, offering a new design paradigm for multifunctional, ROS‐directed photoreactive materials.