Identifying the Key Photosensitizing Factors over Metal‐Organic Frameworks for Selective Control of 1O2 and O2•− Generation

The reaction pathway, product selectivity and catalytic efficiency of photo‐oxidation are highly dependent on the specific reactive oxygen species (ROS), such as singlet oxygen (¹O₂) and superoxide (O₂•−), generated via the sensitization of O2 by photosensitizers. Studies on uncovering the role of photosensitizing factors on the selective control of ¹O₂ and O₂•− generation are significant but remain underexplored. Here, we constructed a photosensitizing metal‐organic framework molecular platform (UiO‐1 – UiO‐4) by elaborately engineering Ir(III) complex ligands with pyrenyl group for modulating photosensitizing factors and elucidating their impact on ROS generation. Impressively, the ratios of 1O2 and O2•− generation varied from 0:100 for UiO‐1 to 94:6 for UiO‐4 by modulating photosensitizing factors. UiO‐2 and UiO‐4 were respectively immobilized in a continuous‐flow reactor, achieving gram‐scale photosynthesis of phenol and juglone with high purity (> 94%) via O₂•− and ¹O₂ pathway, respectively. Investigations reveal that UiO‐4 with ligand localized excited state and long excited state lifetime contributed to triggering energy transfer to afford 1O2, whereas UiO‐1 with charge‐transfer state and negative reduction potential facilitates charge transfer to produce O2•−. This work offers a novel insight into regulating ROS generation by modulating the photosensitizing factors at the molecular level.