Synthesis and crystal structure determination of [PPh4][WO2S2(CuPPh3)] and of [Et4N]2[WS4(CuNCSe)4] with a sheet polymeric anion. Synthesis and characterisation of [PPh4]2[WO2S2(CuNCS)]

Three new copper(I) complexes, [PPh4][WO2S2(CuPPh3)] (1), [PPh4]2[WO2S2(CuNCS)] (2), and [Et4N]2[WS4(CuNCSe)4] (3), have been prepared and characterised. The [WO2S2(CuPPh3)]− anion in 1 represents the first example of copper coordination to the [WO2S2]2− moiety that has been characterised by X-ray crystallography, in contrast to numerous studies involving [WOS3]2− and [WS4]2−. The dithio- and tetrathiotungstate groups in 1 and 3 act as bidentate ligands through two sulphur atoms chelating copper atoms. This is consistent with the infrared spectra, which exhibit low-frequency WSb stretching bands. There is no coordination of oxygen atoms to copper. The copper atom in 1 has trigonal coordination with triphenylphosphine as the third ligand. In 3 the selenocyanate ligands function as bridges, with nitrogen coordinated to one copper atom and selenium to another; pairs of copper atoms are linked by two of these bridges across an inversion centre, to give a two-dimensional polymeric network anion.