Single Crystal XRD Structure and Theoretical Analysis of the Chiral Au30S(S‑t‑Bu)18 Cluster

• Published in: Journal of the American Chemical Society Vol. 136; no. 13; pp. 5000 - 5005
• Main Authors: Crasto, David, Malola, Sami, Brosofsky, Grace, Dass, Amala, Häkkinen, Hannu
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.04.2014
• Subjects: enantiomers; gold; sulfides; sulfur; X-ray diffraction
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/ja412141j

Au30S(S-t-Bu)18 cluster, related closely to the recently isolated “green gold” compound Au30(S-t-Bu)18, has been structurally solved via single-crystal XRD and analyzed by density functional theory calculations. The molecular protecting layer shows a combination of monomeric (RS-Au-SR) and trimeric (RS-Au-SR-Au-SR-Au-SR) gold–thiolate units, bridging thiolates, and a single sulfur (sulfide) in a novel μ3-coordinating position. The chiral gold core has a geometrical component that is identical to the core of the recently reported Au28(SPh-t-Bu)20. Both enantiomers of Au30S(S-t-Bu)18 are found in the crystal unit cell. The calculated CD spectrum bears a close resemblance to that of Au28(SPh-t-Bu)20. This is the first time when two structurally characterized thiol-stabilized gold clusters are found to have such closely related metal core structures and the results may increase understanding of the formation of gold clusters when stabilized by bulky thiolates.