Bis(chlorido)(dimethylsulfoxide-κO)barium(II)

The title compound, [BaCl2(C2H6SO)], forms a Ba6Cl9 cluster in which the BaCl2 units are connected via dimethylsulfoxide (DMSO) and chloride bridges. The central Cl atom of the Ba6Cl9 cluster is located on a threefold inversion axis and is coordinated octahedrally to six barium cations. In the crystal, the clusters are arranged in rows, which are interconnected by the DMSO molecules, forming a three-dimensional network.

The title compound, [BaCl 2 (C 2 H 6 SO)], forms a Ba 6 Cl 9 cluster in which the BaCl 2 units are connected via dimethylsulfoxide (DMSO) and chloride bridges. The central Cl atom of the Ba 6 Cl 9 cluster is located on a threefold inversion axis and is coordinated octahedrally to six barium cations. In the crystal, the clusters are arranged in rows, which are interconnected by the DMSO molecules, forming a three-dimensional network.
The average Ba···Ba distance in the cluster is about 4.69 Å, while the distance between the two bridged barium ions is shorter at 4.3106 (19) Å.
Due to the high symmetry the Ba-DMSO bridge spreads out in all three dimensions (Fig. 3). In the z-dimension wheelshaped structures of the rows of BaCl clusters are visible. The `DMSO-chloride′ bridges are arranged around the wheels.
The closest distance from the BaCl clusters is about 10.6 Å (measured between Cl3 and Cl3 ii ; symmetry code: (ii) 1/3 + y, 2/3 + x, 1/6 -z). There are no classical hydrogen bonds present but there is a small solvent accessible void of ca 63 Å 3 .
A literature search (Allen, 2002) revealed no similar barium-chloride clusters, but there are several examples of barium chloride bridged structures. For instance barium sulfonate complexes with layered structures (Yang et al., 2006) or chloride bridged macrocyclic barium complexes (Arion et al., 2001;Fenske et al. 1993). There exist also clusters of barium and O atoms with a bridging central chloride ion (Drozdov et al., 1994). Furthermore, there exist different examples of barium DMSO complexes (Harrowfield et al., 2004;Pi et al. 2009).

Experimental
The title compound was obtained incidentally as a side-product in the following reaction: Solution A: To a solution of BaCl 2 (1 g) dissolved in methanol (10 ml) was added 1,5 g of tetraethylene glycol. Product B: Phosphomolybdic acid hydrate (0.25 g, 0.54 mmol) was dissolved in acetone (5 ml) and precipitated with an excess of cobaltocenium hexafluorophosphate (0.2 g) in acetonitrile (5 ml).
Product B was then dissolved in acetonitrile (10 ml) and precipitated with solution A. The precipitate was dissolved in hot DMSO (15 ml). After cooling the solution was layered with diethylether. A few colorless crystals the title compound appeared as a side-product after a few weeks.

Refinement
Atoms C1 and C2 were treated isotropically due to thermal disorder. The H atoms were included in calculated positions and treated as rding atoms: C-H = 0.96 Å with U iso (H) = 1.5U eq (C). Potential Solvent Area Volume = 63.2 Å 3 . A small void of less than 1% was found in the crystal structure. It was not considered in the refinement.

Figure 1
A view of the asymmetric unit of the title compound. Three of the four Cl atoms are located on special positions and have partial occupancies of Cl1 1/2, Cl3 1/6 and Cl4 1/3.  A view of the molecular structure of the title compound, with the atom numbering. The displacement ellipsoids are drawn at the 50% probability level. Symmetry codes: (1) -y, x -y, z (2) -x + y, -y, z (3) -x, -y, -z (4) x -y, x, -z (5) y, x + y, -z.

Figure 3
A view along the z-axis of the crystal packing of the title compound.

Bis(chlorido)(dimethylsulfoxide-κO)barium(II)
Crystal data Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.