Toward Understanding the Correlation between the Charge States and the Core Structures in Thiolate-Protected Gold Nanoclusters.

The charge states of thiolate-protected gold nanoclusters (AuNCs) are vital to their stabilities through affecting the number of the valence electrons. However, the origin of the charge states of AuNCs has not been fully understood yet. Herein, through fulfilling the duet-rule derived Au 3 (2 e ) and Au 4 (2 e ) elementary blocks in the grand unified model (GUM), analysis on the substantial crystal structures indicates the charge states of AuNCs can correlate with their core structural packing, especially the number of Au 3 (2 e ) elementary blocks. In addition, aided by the Au 3 (2 e ) block's role in tailoring the population of valence electron, three new AuNCs including Au 18 (SCH 3 ) 14 , Au 30 (SCH 3 ) 20 , and [Au 30 (SCH 3 ) 21 ] - are predicted through controllably specifying the exact number of Au 3 (2 e ) in the core. This work shows that GUM can bridge the gap among the charge states of the cluster, the inner core structure of the cluster, and the detachment of outer ligands via the electron counting rule.