The Structure and Properties of Gold Clusters with Substitution and Attachment of Thiol Groups

Previous theoretical and experimental studies of metal Au n clusters with defined numbers of gold atoms (the so-called magic numbers n = 18, 20, 32, 42, and 72) revealed that they have symmetric hollow structures. The theoretical analysis of the electronic structure of these particles shows that clusters with the given number of transition metal atoms form one common pseudoatom with a completely filled outer electron shell. At the same time, the experimental data indicate that gold nanoclusters with ligands attached to the metal core by thiol terminal groups have a bulk (not hollow) structure. In this study, the geometry of clusters and the energy of the attachment of the SH group to the hollow-cage and bulk Au n structures is theoretically studied, with the number of gold atoms n varying around 18 and 32. It was found that the attachment of several SH groups to the Au n structures transforms them from cage-like to bulk.