Metalation of Porphyrin to Polarize Electric Field of Conjugated Porous Polymers: Efficient Photooxidation for C sp²–O Radical Cross-Coupling Reaction Assisted by Hydrogen Bonds

In this work, two photosensitive porphyrin-based conjugated porous polymers (PCPPs), namely, Am-TPP and Am-TPP(Cu), were designed and constructed via the Suzuki–Miyaura coupling reaction to function as heterogeneous photoredox catalysts for cross-dehydrogenative coupling (CDC) reaction, enabling the highly efficient synthesis of N -hydroxyphthalimide (NHPI) esters. By implanting Cu(II) in the center of porphyrin ring, the microenvironment of PCPPs was precisely modulated: (1) the exciton binding energy of Am-TPP(Cu) decreased significantly; (2) the electric field of framework was polarized, facilitating the transfer of photogenerated electrons from the Am units to the Cu site of TPP(Cu) units. Based on this, Am-TPP(Cu) exhibited a remarkably catalytic performance for photoredox CDC reaction between aldehyde and NHPI, while simultaneously producing H 2 O 2 . Theoretical and experimental investigations have revealed that the Cu atoms of prophyrin cores adsorbed molecular oxygen and functioned as electron collection centers via ligand-to-metal charge transfer (LMCT) to reduce O 2 . Meanwhile, the Am units anchored aldehyde or NHPI through hydrogen bonding interactions and were further oxidized through photogenerated holes, generating active radical intermediates for the CDC reaction. This work expands the potential applications of photosensitive CPPs in photoredox organic transformation through the microenvironment-modulated strategy.