Hexakis(dimethyl sulfoxide-κO)chromium(III) trichloride

In the title compound, [Cr(C2H6OS)6]Cl3, each CrIII ion is located on a three-fold inversion axis and is coordinated by six dimethylsulfoxide ligands [Cr—O = 1.970 (2)–1.972 (2) Å; O—Cr—O = 88.19 (9) and 91.81 (9)°] in a slightly distorted octahedral geometry. The Cl− anions take part in the formation of weak C—H⋯Cl hydrogen bonds, which contribute to the crystal packing stabilization.

In the title compound, [Cr(C 2 H 6 OS) 6 ]Cl 3 , each Cr III ion is located on a three-fold inversion axis and is coordinated by six dimethylsulfoxide ligands [Cr-O = 1.970 (2)-1.972 (2) Å ; O-Cr-O = 88.19 (9) and 91.81 (9) ] in a slightly distorted octahedral geometry. The Cl À anions take part in the formation of weak C-HÁ Á ÁCl hydrogen bonds, which contribute to the crystal packing stabilization.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CV2410).

S1. Comment
Dimethylsulfoxide (dmso) has often been used as solvent and a ligand in inorganic chemistry since the beginning of the 1960th. Dimethylsulfoxide is a monodentate O-,S-donor ligand (Reynolds, 1970). Solvates of some transition metal ions have been prepared and structurally charaterized (Persson et al., 1995 and references therein).
The title compound, (I), is composed of [Cr(C 2 H 6 OS) 6 ] 3+ cations and chloride anions. The Cr(III) ion is located on a 3fold inversion axis being coordinated by the six dimethylsulfoxide ligands in a slightly distorted octahedral geometry In (I), the Cl anions take part in formation of weak C-H···Cl hydrogen bonds (Table 1), which contribute to the crystal packing stabilization.

S2. Experimental
Complex (I) was synthesized during the attempt to prepare chromium (III) complex with 1H-pyrazole-3,5dicarbohydrazide (Fig. 2) by adding CrCl 3 .6H 2 O (0.3 mmol, 3 ml of 0.1M aqueous solution) to the 1H-pyrazole-3,5dicarbohydrazide (0.0552 g, 0.3 mmol) in dimethylsulfoxide solution (6 ml). The mixture was stirred for 30 min at ambient temperature. The resulting green solution was filtered and the filtrate was left to stand at room temperature. Slow evaporation of the solvent during 2 weeks yielded green crystals of (I).

S3. Refinement
The H atoms were positioned geometrically (C-H 0.98 Å) and allowed to ride on their parent atoms, with U iso (H) = 1.5U eq (C).  The molecular structure of (I), showing the atom-numbering scheme and displacement ellipsoids at the 60% probability level [symmetry codes: (i) -x + y, 1 -x, z; (ii) 2/3 + x-y, 1/3 + x, 1/3 -z; (iii) 1 -y, 1 + x-y, z; (iv) -1/3 + y, 1/3 -x + y, 1/3z; (v) 2/3 -x, 4/3 -y, 1/3 -z.]  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.82 e Å −3 Δρ min = −0.48 e Å −3 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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.  (2) C2-H2B 0.9800 S1-O1 1.542 (2) C2-H2C 0.9800 S1-C2 1.770 (3)