Integration of an Electron Donor-Acceptor Pair into MOF for Photocatalytic Aerobic Oxidation

Molecular organization of electron donor and acceptor chromophores both as ligands within a metal-organic framework (MOF) with improved charge transfer efficiency is of paramount interest in artificial photosynthesis yet remains a major challenge. In this work, an electron donor-acceptor (D-A) pair consisting of 5,15-di(p-benzoato)porphyrin (H₂DPBP, donor) and naphthalene diimide (NDI, acceptor) with similar geometry and connectivity was integrated into a highly stable and porous MOF (UiO-66) via a facile one-pot synthetic approach. Benefiting from the efficient photoinduced electron transfer (PET) from the donor H₂DPBP ligand to the acceptor NDI ligand and the energy transfer gifted by the photosensitizer H₂DPBP ligand upon light irradiation, which contribute to the abundant generation of reactive oxygen species of superoxide radical (O₂^•-) and singlet oxygen (¹O₂), respectively, the resulting heteroligand D-A MOF UiO-66-H₂DPBP-NDI exhibits excellent photocatalytic activities toward aerobic oxidation reactions involving the hydroxylation of arylboronic acids and homocoupling of amines under mild conditions. This work presents a new avenue to construct efficient D-A systems by cointegration of electron donor and acceptor both as ligands into one MOF for advanced artificial photosynthesis.