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 Aux (RC≡C)y as counterparts to Aux (SR)y can be expected.