Homoleptic Alkynyl-Protected Gold Nanoclusters: Au₄₄ (PhC≡C)₂₈ and Au₃₆ (PhC≡C)₂₄

For the first time total structure determination of homoleptic alkynyl-protected gold nanoclusters is reported. The nanoclusters are synthesized by direct reduction of PhC≡CAu, to give Au₄₄ (PhC≡C)₂₈ and Au₃₆ (PhC≡C)₂₄ . The Au₄₄ and Au₃₆ nanoclusters have fcc-type Au₃₆ and Au₂₈ kernels, respectively, as well as surrounding PhC≡C-Au-C₂ (Ph)Au-C≡CPh dimeric "staples" and simple PhC≡C bridges. The structures of Au₄₄ (PhC≡C)₂₈ and Au₃₆ (PhC≡C)₂₄ are similar to Au₄₄ (SR)₂₈ and Au₃₆ (SR)₂₄ , but the UV/Vis spectra are different. The protecting ligands influence the electronic structures of nanoclusters significantly. The synthesis of these two alkynyl-protected gold nanoclusters indicates that a series of gold nanoclusters in the general formula Au_x (RC≡C)_y as counterparts to Au_x (SR)_y can be expected.