Solvent-driven reversible transformation between electrically neutral thiolate protected Ag 25 and Ag 26 clusters

Two atom-precise silver nanoclusters [Ag 25 Cl 2 (Tab) 14 (PhCOO) 11 (DMF) 4 ](PF 6 ) 12 ( Ag 25 , DMF= N,N -dimethylformamide) and [Ag 26 Cl 2 (Tab) 14 (PhCOO) 13 (DMAc) 4 ](PF 6 ) 11 (Ag 26 , DMAc= N , N -dimethylacetamide) were synthesized based on the electrically neutral thiolate protective ligand, 4-(trimethylammonio)benzenethiolate (Tab). The weak Ag-S interaction in Tab-protected silver nanoclusters allows to insert or leave a single silver atom in the Ag-S skeleton through solvent-trigger core fragmentation and re-arrangement, thereby realizing the reversible conversion of Ag 25 and Ag 26 for the first time.