Total Structure Determination of Au₁₆(S-Adm)₁₂ and Cd₁Au₁₄(S<i>t</i>Bu)₁₂ and Implications for the Structure of Au₁₅(SR)₁₃

Abstract

Ultrasmall nanoclusters (e.g., Au₁₅(SR)₁₃) are crucial in not only real applications such as bioapplication but also in understanding the structure transition from gold complexes to gold nanoclusters. However, the determination of these transition-sized gold nanoclusters has long been a major challenge. In this work, two new nanoclusters in the transition regime, including the thus far smallest thiolated alloy nanocluster Cd₁Au₁₄(S tBu)₁₂ and the homogold nanocluster Au₁₆(S-Adm)₁₂, are obtained and their atomic structures are fully determined by single crystal X-ray diffraction. Moreover, based on the structures of Cd₁Au₁₄(SR)₁₂ and Au₁₆(SR)₁₂, we perform DFT calculations to predict the structure of the "transformation" nanocluster, Au₁₅ (Au₁₅(SR)₁₂^- and Au₁₅(SR)₁₃). Overall, this work bridges the gaps between gold complexes and nanoclusters.