Synthesis and Properties of an Au6 Cluster Supported by a Mixed N-Heterocyclic Carbene-Thiolate ligand

The preparation of a novel Au6 cluster bearing a bidentate mixed carbene-thiolate ligand is presented. The length of linker between the central benzimidazole and thiolate has a strong effect on the formation of cluster products, with a C2 chain giving an Au6 cluster, while a C3 chain results in no evidence of cluster formation. Density functional theory analysis predicts a non-metallic cluster with a large HOMO-LUMO (3.4 eV) and optical gap.