Chiral Au22(SR)17-: A New Ligand-Binding Strategy for Structural Prediction of Thiolate-Protected Gold Nanocluster

A new atomic structure of chiral thiolate-protected gold nanocluster Au22(SR)17- is predicted on the basis of the new ligand-binding strategy, namely, redistributing the Au-S “staple” motifs on the well-known Au10 core from previously laboratory-determined Au21(SR)15 crystal structure. Density functional theory calculations show that the predicted Au22(SR)17- exhibits high chemical and thermal stabilities. The computed optical absorption spectrum and fluorescent emission spectrum of predicted Au22(SR)17- can well reproduce the experimental measurements, suggesting that this structure is very likely the realistic structure for the synthesized Au22(SR)17-. The new structure of Au22(SR)17- not only offers new chemical insights into the interaction between gold core and thiolate ligands, and validates the new ligand-binding strategy to predict stable thiolate-protected gold nanocluster, but also will motivate future experimental crystallization of the Au22(SR)17- cluster to confirm our prediction.