RESUMEN
Atomically precise gold clusters have attracted considerable research interest as their tunable structure-property relationships have resulted in widespread applications, from sensing and biomedicine to energetic materials and catalysis. In this article, the synthesis and optical properties of a novel [Au6(SbP3)2][PF6]2 cluster are reported. Despite the lack of spherical symmetry in the core, the cluster shows exceptional thermal and chemical stability. Detailed structural attributes and optical properties are evaluated experimentally and theoretically. This, to the best of our knowledge, is the first report of a gold cluster protected via synergistic multidentate coordination of stibine (Sb) and phosphine moieties (P). To further show that the latter moieties give a set of unique properties that differs from monodentate phosphine-protected [Au6(PPh3)6]2+, geometric structure, electronic structure, and optical properties are analyzed theoretically. In addition, this report also demonstrates the critical role of overall-ligand architecture in stabilizing mixed ligand-protected gold clusters.
RESUMEN
We report the first example of a chiral mixed thiolate/stibine-protected gold cluster, formulated as Au18(S-Adm)8(SbPh3)4Br2 (where S-Adm = 1-adamantanethiolate). Single crystal X-ray crystallography reveals the origin of chirality in the cluster to be the introduction of the rotating arrangement of Au2(S-Adm)3 and Au(S-Adm)2 staple motifs on an achiral Au13 core and the subsequent capping of the remaining gold atoms by SbPh3 and Br- ligands. Interestingly, the structure and properties of this new Au18 cluster are found to be different from other reported achiral Au18 clusters and the only other stibine-protected [Au13(SbPh3)8Cl4]+ cluster. Detailed analyses on the geometric and electronic structures of the new cluster are carried out to gain insights into its optical properties as well as reactivity and stability of such mixed monolayer-protected clusters.