Fig. 6.

Schematic illustration of surface motif exchange reaction on Ag₄₄ nanoclusters. a Pristine [Ag₄₄(SR)₃₀]⁴⁻; b association of [Au₂(SR′)₂Cl]⁻ to [Ag₄₄(SR)₃₀]⁴⁻; c Ag–S bond deformation in [Au₂(SR′)₂Cl]⁻ associated [Ag₄₄(SR)₃₀]⁴⁻; d dissociation of AgCl and [Au(SR)₂]⁻; e [Ag₄₃Au(SR)₂₈(SR′)₂]⁴⁻ formed by exchange of one SR–Ag(I)–SR motif and f [Ag₃₂Au₁₂(SR)₆(SR′)₂₄]⁴⁻ produced by complete exchange of twelve SR–Ag(I)–SR motifs, where SR and SR′ denote pristine and foreign thiolate ligands, respectively. For an easy and clear presentation, the Ag atoms in Ag₁₂ inner core and Ag₂₀ external core are shown as gray and light blue large balls, respectively; while the other atoms are shown as small dots (color legend: Ag (gray/light blue/purple), Au (yellow), S (orange/magenta), and Cl (light green)). The hydrocarbon tails and carboxylic groups of the protecting ligands are omitted