Auration of an aryltris[(triarylphosphine)aurio(I)]phosphonium(+) cation to give a hypercoordinate aryltetrakis[(triarylphosphine)aurio(I)]phosphonium(2+) dication

Treatment of (2-methylphenyl)phosphine with tris[(triphenylphosphine)aurio(I)]oxonium(+) tetrafluoroborate(-) affords colorless, air-stable (2-methylphenyl)tris[(triphenylphosphine)aurio(I)] phosphonium(+) tetrafluoroborate(-): (2-MeC 6 H 4 )[Ph 3 PAu] 3 P + BF 4 - (1); Me=methyl, Ph=phenyl. The crystal structure features tetrahedral cations with a central phosphorus atom surrounded by three gold atoms and one carbon atom.