From Monolayer-Protected Gold Cluster to Monolayer-Protected Gold-Sulfide Cluster: Geometrical and Electronic Structure Evolutions of Au60Sn(SR)36 (n = 0–12)

Thiolate-monolayer-protected gold clusters are usually formulated as Au N SR[Au(I)-SR] x , where Au N and SR[Au(I)-SR] x ( x = 0, 1, 2, ...) are the inner gold core and outer protection motifs, respectively. In this work, we theoretically envision a new family of S-atom-doped thiolate-monolayer-protected gold clusters, namely, Au 60 S n (SR) 36 ( n = 0-12). A distinct feature of Au 60 S n (SR) 36 nanoclusters (NCs) is that they show a gradual transition from the monolayer-protected metal NC to the SR[Au(I)-(SR)] x oligomer-protected gold-sulfide cluster with the increase of the number of doping S atoms. The possible formation mechanism of the S-atom-doped thiolate-protected gold cluster is investigated, and the size-dependent stability and electronic and optical absorption properties of Au 60 S n (SR) 36 are explored using density functional theory (DFT) calculations. It is found that doping of S atom significantly tails the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap and optical absorption properties of thiolate-protected gold cluster, representing a promising way to fabricate new monolayer-protected gold nanoparticles.