Same Magic Number but Different Arrangement: Alkynyl‐Protected Au₂₅ with <i>D</i>₃ Symmetry

Abstract

Abstract Two homoleptic alkynyl‐protected gold clusters with compositions of Na[Au 25 (C≡CAr) 18 ] and (Ph 4 P)[Au 25 (C≡CAr) 18 ] (Na⋅ 1 and Ph 4 P⋅ 1 , Ar=3,5‐bis(trifluoromethyl)phenyl) were synthesized via a direct reduction method. 1 is a magic cluster analogous to [Au 25 (SR) 18 ] − in terms of electron counts and metal‐to‐ligand ratio. Single‐crystal structure analysis reveals that 1 has an identical Au 13 kernel to [Au 25 (SR) 18 ] − , but adopts a distinctly different arrangement of the six peripheral dimer staple motifs. The steric hindrance of alkynyl ligands is responsible for the D 3 arrangement of Au 25 . The introduction of alkynyl also significantly changes the optical absorption features of the nanocluster as supported by DFT calculations. This magic cluster confirms that there is a similar but quite different parallel alkynyl‐protected metal cluster universe in comparison to the thiolated one.