Year: 2026
Type: preprint
Abstract: Ligand exchange reactions provide a route to modify the monolayers of atomically precise gold clusters, but the structural dynamics of the process remain poorly understood. In this work, we use collision-initiated direct dynamics driven by a semiempirical electronic-structure method to study ligand exchange on Au38(PET)24, where PET denotes 2-phenylethanethiolate. The incoming ligands are thiophenol and two para-substituted derivatives, each considered in both its thiol and thiophenolate forms. The trajectories resolve the proposed associative mechanism as a sequence of ligand addition and elimination, followed by substantial restructuring of the core-monolayer interface and incorporation of the incoming ligand into the monolayer. The displaced PET ligand remains associated with the cluster, making desorption a distinct subsequent step required to form fully separated products. Comparisons among the incoming ligands show that both protonation state and para substitution influence how far the trajectories progress. These simulations provide a direct atomistic view of ligand exchange and show that the process involves extensive reorganization of the cluster–monolayer interface.
Source: ChemRxiv
Authors: Jesse Delmage, Irina Paci
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7213985231