Synthesis and crystal structure determination of [PPh 4][WO 2S 2(CuPPh 3)] and of [Et 4N] 2[WS 4(CuNCSe) 4] with a sheet polymeric anion. Synthesis and characterisation of [PPh 4] 2[WO 2S 2(CuNCS)

Abstract

Three new copper(I) complexes, [PPh 4][WO 2S 2(CuPPh 3)] ( 1), [PPh 4] 2[WO 2S 2(CuNCS)] ( 2), and [Et 4N] 2[WS 4(CuNCSe) 4] ( 3), have been prepared and characterised. The [WO 2S 2(CuPPh 3)] − anion in 1 represents the first example of copper coordination to the [WO 2S 2] 2− moiety that has been characterised by X-ray crystallography, in contrast to numerous studies involving [WOS 3] 2− and [WS 4] 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S b 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.