Crystal Structure of Barrel-Shaped Chiral Au₁₃₀(<i>p</i>‑MBT)₅₀ Nanocluster

Abstract

We report the structure determination of a large gold nanocluster formulated as Au₁₃₀(<i>p</i>-MBT)₅₀, where <i>p</i>-MBT is 4-methylbenzene­thiolate. The nanocluster is constructed in a four-shell manner, with 55 gold atoms assembled into a two-shell Ino decahedron. The surface is protected exclusively by –S–Au–S– staple motifs, which self-organize into five ripple-like stripes on the surface of the barrel-shaped Au₁₀₅ kernel. The Au₁₃₀(<i>p-</i>MBT)₅₀ can be viewed as an elongated version of the Au₁₀₂(SR)₄₄. Comparison of the Au₁₃₀(<i>p-</i>MBT)₅₀ structure with the recently discovered icosahedral Au₁₃₃(<i>p-</i>TBBT)₅₂ nanocluster (where <i>p-</i>TBBT = 4-<i>tert</i>-butyl­benzene­thiolate) reveals an interesting phenomenon that a subtle ligand effect in the para-position of benzenethiolate can significantly affect the gold atom packing structure, i.e. from the 5-fold twinned Au₅₅ decahedron to 20-fold twinned Au₅₅ icosahedron