THE DMSO SOLVATED OCTAHEDRO-[W6CL12I]CL-6(A) CLUSTER-MOLECULE

Octahedro-hexatungsten octadecachloride, W6Cl18, is soluble in dimethy l sulfoxide (DMSO). Brownish black crystals of W6Cl18(DMSO)(4) are for med from the brown solution by evaporation of DMSO under dynamic vacuu m. The compound crystallizes monoclinically in the space group P2(1)/n (no. 14) with a = 10.420 Angstrom, b = 9.271 Angstrom, c = 20.828 Ang strom, beta = 91.10 degrees and Z = 2. The crystal structure is formed by isolated cluster molecules [W6Cl12i]Cl-6(a) of the hexameric tungs ten trichloride and DMSO molecules. It is the first hierarchical varia nt of the tetragonal BaAl4 type of structure where all atoms of the in termetallic phase are substituted by neutral molecules. The mean bond lengths are d(W-W) = 2.878 Angstrom, d(W-Cl-i) = 2.391 Angstrom and d( W-Cl-a) = 2.447 Angstrom. They will be discussed in relation to analog ous clusters. The two crystallographically independent DMSO molecules (d(S-O) = 1.53-1.55 Angstrom, d(S-C) = 1.65-1.78 Angstrom) form a 3D n et of condensed [4(8)6(4)] dodecahedra which envelopes the clusters.