Synthesis and Structure of the Ionic Complexes [Ph3PEt][Au(CN)2Cl2] and [Ph3PCH2CH2Br][Au(CN)2Br2]

The reactions of potassium dichloro- and dibromodicyanoaurate with appropriate ethyl and (2-bromoethyl)triphenylphosphonium halides in water gave new dihalodicyanoaurate complexes [Ph3PE-t][Au(CN)(2)Cl-2] (I) and [Ph3PCH2CH2Br][Au(CN)(2)Br-2] (II), which were characterized by X-ray diffraction (CCDC nos. 1963511 (I) and 2060274 (II)). According to X-ray diffraction data, complexes I and II consist of tetrahedral organyltriphenylphosphonium cations and two types of crystallographically independent square planar dihalodicyanoaurate anions with similar geometric parameters. The phosphorus atoms in the phosphonium cations have a slightly distorted tetrahedral coordination. The centrosymmetric crystallographically independent anions [Au(CN)(2)Cl-2](-) in I have a nearly undistorted square planar geometry, whereas the geometry of the [Au(CN)(2)Br-2](-) anions in II is substantially distorted (the CAuBr cis-angles vary in the range of 74.5(9)degrees-105.5(9)degrees). The spatial organization in the crystals of I and II is formed by the C-H center dot center dot center dot N equivalent to C hydrogen bonds and, in the case of complex II, also by additional inter-ion C-H center dot center dot center dot Br-Au contacts.