Small Gold(I) and Gold(I)-Silver(I) Clusters by C-Si Auration.

Auration of o-trimethylsilyl arylphosphines leads to the formation of gold and gold-silver clusters with ortho-metalated phosphines displaying 3c-2e Au-C-M bonds (M=Au/Ag). Hexagold clusters [Au L ](X) are obtained by reaction of (L-TMS)AuCl with AgX, whereas reaction with AgX and Ag O leads to gold-silver clusters [Au Ag L ](X) . Oxo-trigold(I) species [Au O] were identified as the intermediates in the formation of the silver-doped clusters. Other [Au ], [Au Ag], and [Au Ag ] clusters were also obtained. Clusters containing PAu-Au-AuP structural motif display good catalytic activity in the activation of alkynes under homogeneous conditions.