Sc(OTf) ₃ -induced, selective removal of alkynyl ligands from heteroleptic Au ₁₃ and Au ₃₈ nanoclusters

The heteroleptic gold nanoclusters [Au₁₃(dppe)₅(PA)₂]³⁺ (dppe = 1,2-bis(diphenylphosphino)ethane; PA^- = phenylacetylide) and [Au₃₈(PPh₃)₄(PA)₂₀]²⁺ underwent the removal of PA^- and an [Au(PA)₂]^- staple unit, respectively, via reaction with the Lewis acid scandium trifluoromethanesulfonate (Sc(OTf)₃). The surface-exposed [Au₃₇(PPh₃)₄(PA)₁₈]³⁺ obtained from the Au₃₈ nanocluster self-assembled into a dimer with two di-isocyanide linker molecules. This non-thermal strategy provides a foundation for the targeted synthesis of novel AuNCs with well-defined naked sites that can act as selective catalysts or building blocks for assembled materials.