The Structure and Optical Properties of the [Au18(SR)14] Nanocluster

Decreasing the core size is one of the best ways to study the evolution from Au-I complexes into Au nanoclusters. Toward this goal, we successfully synthesized the [Au-18(SC6H11)(14)] nanocluster using the [Au-18(SG)(14)] (SG=L-glutathione) nanocluster as the starting material to react with cyclohexylthiol, and determined the X-ray structure of the cyclohexylthiol-protected [Au-18(C6H11S)(14)] nanocluster. The [Au-18(SR)(14)] cluster has a Au-9 bi-octahedral kernel (or inner core). This Au-9 inner core is built by two octahedral Au-6 cores sharing one triangular face. One transitional gold atom is found in the Au-9 core, which can also be considered as part of the Au-4(SR)(5) staple motif. These findings offer new insight in terms of understanding the evolution from [Au-I(SR)] complexes into Au nanoclusters.