Halocuprates(I) crystallising with the Ph3PNPPh3 + cation: preparation and structural characterisation of (Ph3PNPPh3)2[Cu4Br6] and (Ph3PNPPh3)[CuBrCl]

Two halocuprates(I) crystallising with the Ph3PNPPh3 + cation, (Ph3PNPPh3)2[Cu4Br6] (1) and (Ph3PNPPh3)[CuBrCl] (2), have been prepared and characterised by means of crystal-structure determination. The anion in 1 is a tetranuclear species composed of vertex-sharing copper(I)–bromide triangles. It may, alternatively, be described in terms of an octahedron of bromide ions containing a tetrahedron of copper(I) ions. There are two possible orientations of the copper(I) tetrahedron which results in partial occupancy of the crystallographic copper(I) sites. The anion in 2 is also disordered with bromide and chloride occupying the halide sites to differing degrees, resulting in the composition [CuBr1.46Cl0.54]−. In both compounds the Ph3PNPPh3 + cation exhibits an intramolecular claw-like conformation with offset face-to-face orientation of two phenyl rings; but the orientation of the cation claws with respect to the anion differs considerably between the two compounds.