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

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 Å) 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.

S. Vergara, D. A. Lukes, and M. W. Martynowycz contributed equally to this work. Correspondence to: [email protected], [email protected], and [email protected]