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

\Au30S(S-t-Bu)(18) cluster, related closely to the recently isolated "green gold" compound Au-30(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 mu(3)-coordinating position. The chiral gold core has a geometrical component that is identical to the core of the recently reported Au-28(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 Au-28(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.