Structural prediction of anion thiolate protected gold clusters of [Au28+7n(SR)17+3n]- (n = 0-4).

Abstract

Structural prediction of thiolate-protected gold nanoclusters (AuNCs) with diverse charge states can enrich the understanding of this species. Untill now, the number of anion AuNCs is still deficient. In this work, a series of gold nanoclusters with negative total charge, including [Au28(SR)17]-, [Au35(SR)20]-, [Au42(SR)23]-, [Au49(SR)26]-, and [Au56(SR)29]-, are designed. Following a crystallized [Au23(SR)16]- prototype structure, the inner core of the newly predicted clusters is obtained through packing crossed Au7. Next, proper protecting thiolate ligands are arranged to fulfill the duet rule to obtain Au3(2e) and Au4(2e). Extensive analysis indicates that these clusters own high stabilities. Molecular orbital analysis shows that the orbitals for the populations of the valence electron locate at each Au3(2e) and Au4(2e), which demonstrates the reliability of the grand unified model. This work should be helpful for enriching the structural diversity of AuNCs.