Document Type

Article

Publication Date

4-1-2025

Department

Department of Physics

Abstract

The synthesis of ligand-conjugated gold nanoclusters has attracted significant attention due to its ability to achieve precise control over cluster size selectivity. Among these, Au25(SR)18-, where R represents an alkyl group, is one of the earliest being synthesized with a very high yield, although its growth mechanism is yet to be fully understood. Using density functional theory, we present the results of a theoretical investigation on the growth process of Au25(SR)18-, beginning from Au13(SR)12-. Our findings indicate that the sulfur atoms in the core structure of Au13(SR)12- preferentially bond with Au-thiol monomers. Monomers attached to two adjacent triangular faces form a staple motif of the gold-sulfur chain, releasing a single linear thiol radical. These reactions occur along the six mutually perpendicular ridges of the Au13 core. The remaining eight triangular faces, linked with linear alkyl parts, cannot bind additional Au-thiol monomers, stopping cluster growth. Furthermore, the capping gold-sulfur chains play a protective role for the core, facilitating the stable formation of the Au25(SR)18-cluster, as confirmed experimentally.

Publisher's Statement

Publisher's record: https://doi.org/10.1021/acsomega.4c11441

© 2025 The Authors. Published by American Chemical Society

Publication Title

ACS Omega

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