Accurate Thermal Resection of Atomically Precise Copper Clusters to Achieve Near‐IR Light‐Driven CO2 Reduction

Abstract Atomically precise copper clusters are desirable as catalysts for elaborating the structure–activity relationships. The challenge, however, lies in their tendency to sinter when protective ligands are removed, resulting in the destruction of the structural integrity of the model system. Herein, a copper‐sulfur‐nitrogen cluster [Cu 8 (S t Bu) 4 (PymS) 4 ] (denoted as Cu 8 SN ) is synthesized by using a mixed ligand approach with strong chelating 2‐mercaptopyrimidine (PymSH) ligands and relatively weak monodentate tert‐butyl mercaptan ligands. A precise thermal‐resection strategy is applied to selectively peel only the targeted weak ligands off, which induces a structural transformation of the initial Cu 8 cluster into a new and more stable Cu–S–N cluster [Cu 8 (S) 2 (PymS) 4 ] (denoted as Cu 8 SN‐T ). The residual bridging S 2− within the metal core forms asymmetric Cu‐S species with a near‐infrared (NIR) response, which endows Cu 8 SN‐T with the capability for full‐spectrum responsive CO 2 photoreduction, achieving a ≈100% CO 2 ‐to‐CO selectivity. Especially for NIR‐driven CO 2 reduction, it has a CO evolution of 42.5 µmol g −1 under λ > 780 nm. Importantly, this work represents the first NIR light‐responsive copper cluster for efficient CO 2 photoreduction and opens an avenue for the precise manipulation of metal cluster structures via a novel thermolysis strategy to develop unprecedented functionalized metal cluster materials.