Thiolated Disc Nanoclusters with Pseudo-6-fold Symmetry

The formation of core-shell metal nanoclusters (NCs) with high symmetry remains significantly challenging. Here, we report the first synthesis and atomically precise structures of two discoidal clusters, <b>Ag</b>_<b>69</b> and <b>Ag</b>_<b>78</b>, protected by mixed thiol ligands, both exhibiting rare pseudo-6-fold symmetry, with crystallographic disorder considered. While their sizes and skeletons are similar, the key difference arises from the introduction of Cl^- ions from in situ decomposition of CH₂Cl₂ in the assembly of <b>Ag</b>_<b>69</b>. Replacing Cl^-, S^2- ions occupy the same positions in <b>Ag</b>_<b>78</b>, leading to stronger silver-sulfur coordination and closer silver-silver distances. Notably, within the crystal lattice of <b>Ag</b>_<b>69</b>, an additional Ag78 forms at the same location. <b>Ag</b>_<b>69</b> and <b>Ag</b>_<b>68</b> share an identical outer shell of Ag₅₄S₆(^<i>t</i>BuS)₂₄(^<i>t</i>BuPhS)₂₄, but differ at the core, with <b>Ag</b>_<b>69</b> having Ag₁₅Cl₆(^<i>t</i>BuPhS)₂ and <b>Ag</b>_<b>68</b> having Ag₁₄Cl₆(^<i>t</i>BuS)₂. We also discuss the photoluminescent properties, and the photocatalytic degradation of organic dyes is also discussed. This work provides valuable insights into the formation of high-symmetry metal NCs and their potential applications in photochemistry.