Dithiocarbonate-Protected Au₂₅ Nanorods of a Chiral D₅ Configuration and NIR-II Phosphorescence

Innovative surface-protecting ligands are in constant demand due to their crucial role in shaping the configuration, property, and application of gold nanoclusters. Here, the unprecedented O-ethyl dithiocarbonate (DTX)-stabilized atomically precise gold nanoclusters, [Au₂₅(PPh₃)₁₀(DTX)₅Cl₂]²⁺ (Au-Cl) and [Au₂₅(PPh₃)₁₀(DTX)₅Br₂]²⁺ (Au-Br), were synthesized and structurally characterized. The introduction of bidentate DTX ligands not only endowed the gold nanocluster with unique staggered Au₂₅ nanorod configurations but also generated the symmetry breaking from the D_5d geometry of the Au₂₅ kernels to the chiral D₅ configuration of the Au₂₅ molecules. The chirality of Au₂₅ nanorods was notably revealed through single-crystal X-ray diffraction, and chiral separation was induced by employing chiral DTX ligands. The staggered configurations of Au₂₅ nanorods, as opposed to eclipsed ones, were responsible for the large red shift in the emission wavelengths, giving rise to a promising near-infrared II (NIR-II, >1000 nm) phosphorescence. Furthermore, their performances in photocatalytic sulfide oxidation and electrocatalytic hydrogen evolution reactions have been examined, and it has been demonstrated that the outstanding catalytic activity of gold nanoclusters is highly related to their stability.