MicroED structure of Au146(p-MBA)57 at subatomic resolution reveals a twinned FCC cluster

TL;DR

This study reveals the atomic structure of a gold cluster Au146(p-MBA)57 at subatomic resolution, showing a twinned FCC core and detailed surface motifs, advancing understanding of metallic cluster structures.

Contribution

The paper presents the first subatomic resolution structure of Au146(p-MBA)57, combining MicroED and X-ray diffraction to elucidate its twinned FCC core and surface motifs.

Findings

Revealed a twinned FCC structure in Au146(p-MBA)57

Identified the core and surface atom organization

Observed the smallest gold particle with a stacking fault

Abstract

Solving the atomic structure of metallic clusters is fundamental to understanding their optical, electronic, and chemical properties. We report the structure of Au$_{\text{146}}$(p-MBA)$_{\text{57}}$ at subatomic resolution (0.85 {\AA}) using electron diffraction (MicroED) and atomic resolution by X-ray diffraction. The 146 gold atoms may be decomposed into two constituent sets consisting of 119 core and 27 peripheral atoms. The core atoms are organized in a twinned FCC structure whereas the surface gold atoms follow a C$_{2}$ rotational symmetry about an axis bisecting the twinning plane. The protective layer of 57 p-MBAs fully encloses the cluster and comprises bridging, monomeric, and dimeric staple motifs. Au$_{\text{146}}$(p-MBA)$_{\text{57}}$ is the largest cluster observed exhibiting a bulk-like FCC structure as well as the smallest gold particle exhibiting a stacking fault.