Enhancing the Stability and Catalytic Performance of Gold Subnanoclusters Mediated by Au···H–C Hydrogen Bonding and Au···π Interactions

TL;DR

This paper explores how weak interactions like Au···H–C and Au···π can stabilize gold subnanoclusters, improving their catalytic performance and practical use.

Contribution

The study introduces a novel stabilization mechanism for AuSNCs using Au···H–C and Au···π interactions, supported by experimental and computational evidence.

Findings

Au···H–C and Au···π interactions significantly enhance the stability of AuSNCs.

DFT and NCI analyses reveal the role of weak interactions in stabilizing transition states during catalysis.

Functional groups influence the stabilization ability of the AuSNCs system.

Abstract

Gold subnanoclusters (AuSNCs) exhibit remarkable catalytic
activity;
however, their short-lived transient existence and strong tendency
for self-aggregation remain disadvantageous for practical application.
Considering that weak secondary interactions, such as Au···H–C
or Au···π, could enhance the stability of the
subnanocluster system, we have assessed their influence on the stabilization
through a combination of experimental and computational analyses.
We have evaluated the stabilization ability of different functional
groups toward the AuSNCs system. Matrix-assisted laser desorption/ionization-time
of flight (MALDI-TOF) experiments, density functional theory (DFT)
calculations, and topological tools (QTAIM and NCI) provide decisive
insights into the mechanism of stabilization of the short-lived AuSNCs
species. Additionally, we extended the stabilization analysis to an
application in catalysis. By conducting a complete NCI analysis of
an optimized energy pathway, we demonstrate how an Au3 subnanocluster
can be stabilized by a series of weak secondary interactions, including
hydrogen bonds to gold (Au···H–C) as well as
Au···π interactions in intermediates and transition
states.

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