Oxygen Activation‐Driven Selective Oxidation Over Spatially π‐Extended Triphenylene Frameworks

ABSTRACT The selective oxidation of hydrocarbons with molecular oxygen (O 2 ) is a pivotal but energy‐intensive process, with the primary energy consumption arising from the activation of the robust O═O bond. While emerging organic photocatalysts offer a sustainable route for O 2 activation under mild conditions, the prevailing mental model often involves first generating H 2 O 2 as an intermediate oxidant. Consequently, the scalable construction of efficient metal‐free systems capable of directly coupling O 2 activation with selective transformations remains a formidable challenge. Herein, a 3D, spatially π‐extended triphenylene framework (HCP‐TP‐FDA) is synthesized scalably via a simple Friedel–Crafts reaction. This hyper‐cross‐linked polymer bypasses complex monomer design and exhibits outstanding photocatalytic performance in O 2 activation. This unique capability enables efficient H 2 O 2 production (5.57 mmol g −1 h −1 ) and selective oxidation of cyclohexane to KA oil (515 µmol g −1 h −1 ) and the hydroxylation of phenol to dihydroxybenzene (167 µmol g −1 h −1 ). Mechanistic studies reveal that the synergy between electron‐rich triphenylene units and 3D conjugation facilitates directional charge migration along organized π–π stacks—a mechanism reminiscent of natural light‐harvesting systems. This process effectively promotes exciton dissociation and O 2 activation, leading to the versatile generation of reactive oxygen species.