Auration of o-trimethylsilyl arylphosphines leads to the formation of gold and gold–silver clusters with orthometalated phosphines displaying 3c–2e Au@C@M bonds (M=Au/Ag). Hexagold clusters [Au6L4](X)2 are obtained by reaction of (L@TMS)AuCl with AgX, whereas reaction with AgX and Ag2O leads to gold–silver clusters [Au4Ag2L4](X)2. Oxo-trigold(I) species [Au3O]+ were identified as the intermediates in the formation of the silver-doped clusters. Other [Au5], [Au4Ag], and [Au12Ag4] clusters were also obtained. Clusters containing PAu@Au@AuP structural motif display good catalytic activity in the