Abstract: | Octahedro-hexatungsten octadecachloride, W6Cl18, is soluble in dimethyl sulfoxide (DMSO). Brownish black crystals of W6Cl18(DMSO)4 are formed from the brown solution by evaporation of DMSO under dynamic vacuum. The compound crystallizes monoclinically in the space group P21/n (no. 14) with a = 10.420 Å, b = 9.271 Å, c = 20.828 Å, β = 91.10° and Z = 2. The crystal structure is formed by isolated cluster molecules W6Cl ]Cl of the hexameric tungsten trichloride and DMSO molecules. It is the first hierarchical variant of the tetragonal BaAl4 type of structure where all atoms of the intermetallic phase are substituted by neutral molecules. The mean bond lengths are d(W–W) = 2.878 Å, d(W–Cli) = 2.391 Å and d(W–Cla) = 2.447 Å. They will be discussed in relation to analogous clusters. The two crystallographically independent DMSO molecules (d(S–O) = 1.53–1.55 Å, d(S–C) = 1.65–1.78 Å) form a 3 D net of condensed < 4864 > dodecahedra which envelopes the clusters. |