Fig. 4.
Schematic illustration of size-conversion reaction dynamics. a Structure of [Au23(SR)16]−, b association of 2 SR-[Au(I)-SR]2, c dissociation of 2 SR-Au(I)-SR, d core structure transformation, e surface rearrangement, and f structure relaxation to [Au25(SR)18]−. SR denotes thiolate ligand. The hub atoms and middle layer of Au13 core in [Au23(SR)16]− are highlighted in blue and green, respectively, for easy identification. The formation of dimeric SR-[Au(I)-SR]2 motifs #1–#3 is shown by glowing belts in e, and the S atoms and Au atoms involved in the formation of such dimeric motif #3 are indicated by wine and orange arrows, respectively. The core structure at each step is shown at left bottom of each panel