Isomeric Thiolate Monolayer Protected Au92 and Au102 Nanomolecules

We report the results of a study of the isomeric thiolate monolayer capping of two gold nanocluster molecules, namely Au92 and Au102 , both protected by 44 4-tert-butylbenzene thiolate (TBBT) ligands. The finding of an isomeric monolayer of the same ligand in a series of metal nanocluster molecules in this large size range, is unprecedented. Au92 and Au102 possess entirely different structures and properties. The Au92 has an 84 atom face centered cubic (FCC) core whereas Au102 has a 79 atom Marks-decahedral core. Nevertheless, despite the metal core structural diversity and the complexities of the interfacial staples, both of these have the same number of ligands. The Au92 core is protected by 28 bridging ligands and 8 monomeric staple motifs whereas Au102 is protected by 19 monomeric and 2 dimeric staple motifs. The Au92 and Au102 cores have cuboidal and globular structures, respectively. As a result, Au92 has longer {100} facets and exhibits c(2x2) monolayer arrangement for bridging ligands similar to w...