Total Structure Determination of Au-16(S-Adm)(12) and Cd1Au14(StBu)(12) and Implications for the Structure of Au-15(SR)(13)

Ultrasmall nanoclusters (e.g., Au-15(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(StBu)(12) and the homogold nanocluster Au-16(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 Au-16(SR)(12), we perform DFT calculations to predict the structure of the transformation nanocluster, Au-15(Au-15(SR)(12)(-) and Au-15(SR)(13)). Overall, this work bridges the gaps between gold complexes and nanoclusters.