Crystal structures of fourteen halochalcogenylphos-pho-nium tetra-halogenidoaurates(III)

The structures of fourteen halochalcogenyl-phospho-nium tetra-halogen-ido-aurates(III), phosphane chalcogenide derivatives with general formula [R ¹ _3- ² PEX][AuX ₄] (R ¹ = t-butyl; R ² = isopropyl; n = 0 to 3; E = S or Se; X = Cl or Br) are presented. The eight possible chlorido derivatives are: 17 , n = 3, E = S; 18 , n = 2, E = S; 19 , n = 1, E = S; 20 , n = 0, E = S; 21 , n = 3, E = Se; 22 , n = 2, E = Se; 23 , n = 1, E = Se; and 24 , n = 0, E = Se, and the corresponding bromido derivatives are 17 -24 in the same order. Structures were obtained for all compounds except for the tri-t-butyl derivatives 24 and 24 . Isotypy is observed for 18 /18 /22 /22 , 19 /23 , 17 /21 and 19 /23 . In eleven of the compounds, X⋯X contacts (mostly very short) are observed between the cation and anion, whereby the E-X⋯X groups are approximately linear and the X⋯X-Au angles approximately 90°. The exceptions are 17 , 19 and 23 , which instead display short E⋯X contacts. Bond lengths in the cations correspond to single bonds P-E and E-X. For each group with constant E and X, the P-E-X bond-angle values increase monotonically with the steric bulk of the alkyl groups. The packing is analysed in terms of E⋯X, X⋯X (some between anions alone), H⋯X and H⋯Au contacts. Even for isotypic compounds, some significant differences can be discerned.