Triaurated Phosphonium Cations [RP(AuPPh)3]⊕ and the Electron‐deficient, Hypercoordinated Phosphonium Dication [P(AuPPh3)5]2⊕

The auration of arylphosphanes by reaction with [(Ph3PAu)3O]BF4 affords the triauriophosphonium salt 1, while reaction of P(SiMe3)3 with this oxonium salt yields 2, which has a hypercoordinated P center. The cation of 1 has an almost ideal tetrahedral geometry about the central P atom. The large radius of the P atom leads to large peripheral Au…︁Au distances of 3.7 Å. R = o-tolyl.