First Examples of Au^I−X−Ag^I Halonium Cations (X = Cl and Br)

Novel {[(μ-PAnP)(AuX)₂]₂Ag}⁺SbF₆^- halonium ions (X = Cl, Br; PAnP = 9,10-bis(diphenylphosphino)anthracene) were synthesized from the reactions between (μ-PAnP)(AuX)₂ and 1/2 mol equiv of AgSbF₆. The compounds feature an unprecedented distorted Au₄X₄ dodecahedron which encapsulates a silver(I) ion at its center. The halonium ions are stabilized by collective actions of metallophilic Au−Ag, aromatic π−π, and Ag−X interactions.