Reticular Synthesis of 3D Metal Cluster‐Based COFs With Record High‐Connectivity for Efficient Photocatalytic H ₂ O ₂ Synthesis

Abstract

Abstract The assembly of metal clusters with organic building units by covalent bonds to form metal cluster‐based covalent‐organic frameworks (MCCOFs) material is a novel strategy in reticular synthesis. However, only 2, 3, and 6 connectivity of MCCOFs have been achieved in reported structures. Developing a higher connectivity remains a great challenge in the MCCOFs due to the difficulties in introducing multiple connecting nodes to the metal cluster. In this work, two 3D [8 + 2]‐connected MCCOFs were synthesized by condensing an 8‐connectivity aluminum cluster‐based building block (termed Al 8 ‐8c) with linear dialdehyde linkers. Furthermore, these AlCCOFs showed efficient photocatalytic O 2 ‐to‐H 2 O 2 conversion due to the suitable energy band structure, efficient photoelectron conversion capability and the AlCCOF‐1 showed H 2 O 2 photosynthetic efficiency of 16794.69 µmol g −1 h −1 using water and benzyl alcohol reaction system. The in situ EPR, in situ FTIR, and DFT calculations were then performed to study the structure‐function relationships on the two AlCCOFs for H 2 O 2 photosynthesis. This work is the first report of high‐connectivity MCCOFs bearing 8‐connected cluster units, showing the great potential of using metal clusters to construct complicate reticular frameworks by covalent linkage.