TRIANGULAR W3S-7(4+) AND W3S-4(4+) COMPLEXES

Methods for the synthesis of triangular thiohalogenide complexes of tungsten W3S7X4 (XCl, Br) proceeding from metallic tungsten or WS3 have been developed. Ways have been found for converting these polymeric complexes to triangular W3S7X62- complexes which preserve the architecture of the W3(μ3-S)(μ2-S2)34+ cluster fragment. Heating W3S7X4 in a PPh4X melt or in concentrated acids HX in the presence of Et4NX afforded PPh4+ and Et4N+ salts of W3S7X62- (XCl, Br). The structure of (Ph4P)2W3S7Br6 (III) was established by X-ray diffraction analysis. The crystals of III are orthorhombic, a=18.082(2), b=25.834(3), c=27.370(2) Å, Z=8, Pbca, R (Rw)=0.049 (0.055). The Et4N+ salt of W334S7Br62- has been obtained and a calculation of the normal vibrations has been performed for W3S7Br62-. Interaction of W3S7Br4, with a KNCS melt or an aqueous solution of (NH4)2Sx involves transformation of the cluster fragment W3S74+ to a W3S44+ fragment to produce W3S4(NCS)95- and W3S4(S4)3(NH3)32- complexes. The structure of (NH4)(H)(H2O)3W3S16(NH3)3 (VI) was established by X-ray diffraction analysis. The crystals of VI are trigonal, a=12.508(1), c=10.112(1) Å, Z=2, P31c, R (Rw)=0.029 (0.033). © 1990.