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

In the title compound, [Cr(C₂H₆OS)₆]Cl₃, 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⁻ anions take part in the formation of weak C—H...Cl hydrogen bonds, which contribute to the crystal packing stabilization.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](S-C) = 0.004 Å
• R factor = 0.042
• wR factor = 0.135
• Data-to-parameter ratio = 22.7

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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(C₂H₆OS)₆]³⁺ cations and chloride anions. The Cr(III) ion is located on a 3-fold inversion axis being coordinated by the six dimethylsulfoxide ligands in a slightly distorted octahedral geometry (Fig. 1), with Cr—O 1.970 (2)–1.972 (2) Å interatomic distances and O—Cr—O 88.19 (9), 91.81 (9)° bond angles. A search in the Cambridge Structural Database revealed 14 reports of compounds containing transition metal hexakis(dimethylsulfoxide) cations, of which two described the structure of the [Cr(C₂H₆OS)₆]³⁺ cation in [Cr(C₂H₆OS)₆](ClO₄)₃ (Chan et al., 2004) and [Cr(C₂H₆OS)₆](NO₃)₃ (Ohrstrom & Svensson, 2000). The S═O bond lengths in the aforementioned compounds are almost identical, 1.542 (3) Å versus 1.543 (2) Å for the title compound, as well as the O—Cr—O angles, 87.9/92.2° versus 88.19–91.81°. In the present structure the average value of Cr—O—S angles (121.9°) is somewhat smaller than that in [Cr(C₂H₆OS)₆](NO₃)₃ (123.6°). All other angles and bonds of the title compound are very similar to the above mentioned structures.

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.

Related literature

For related literature, see: Chan et al. (2004); Desiraju & Steiner (1999); Ohrstrom & Svensson (2000); Persson et al. (1995, and references therein); Reynolds (1970).

S2. Experimental

Complex (I) was synthesized during the attempt to prepare chromium (III) complex with 1H-pyrazole-3,5-dicarbohydrazide (Fig. 2) by adding CrCl₃.6H₂O (0.3 mmol, 3 ml of 0.1M aqueous solution) to the 1H-pyrazole-3,5-dicarbohydrazide (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).

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. 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, 1/3 - z; (v) 2/3 - x, 4/3 - y, 1/3 - z.]
	Fig. 2. 1H-pyrazole-3,5-dicarbohydrazide

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

Crystal data

[Cr(C2H6OS)6]Cl3	Dx = 1.533 Mg m^−3
Mr = 627.12	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 6073 reflections
Hall symbol: -R 3	θ = 1.0–27.5°
a = 10.5499 (6) Å	µ = 1.20 mm^−1
c = 21.1370 (13) Å	T = 120 K
V = 2037.4 (2) Å^3	Block, green
Z = 3	0.34 × 0.29 × 0.20 mm
F(000) = 981

Data collection

Nonius KappaCCD diffractometer	1044 independent reflections
Radiation source: fine-focus sealed tube	855 reflections with I > 2σ(I)
Horizontally mounted graphite crystal monochromator	Rint = 0.051
Detector resolution: 9 pixels mm^-1	θmax = 27.6°, θmin = 2.4°
ϕ scans and ω scans with κ offset	h = −13→13
Absorption correction: multi-scan (North et al., 1968)	k = −13→13
Tmin = 0.688, Tmax = 0.795	l = −26→27
10865 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.135	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0789P)^2 + 3.3338P] where P = (Fo^2 + 2Fc^2)/3
1044 reflections	(Δ/σ)max < 0.001
46 parameters	Δρmax = 0.82 e Å^−3
0 restraints	Δρmin = −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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cr1	0.3333	0.6667	0.1667	0.0214 (3)
Cl1	0.0000	0.0000	0.0000	0.0324 (5)
Cl2	0.0000	0.0000	0.25064 (7)	0.0416 (4)
S1	0.24193 (8)	0.38772 (8)	0.08860 (4)	0.0261 (3)
O1	0.3687 (2)	0.5325 (2)	0.11455 (10)	0.0270 (5)
C1	0.3083 (4)	0.3721 (4)	0.01371 (16)	0.0336 (7)
H1A	0.3141	0.4485	−0.0145	0.050*
H1B	0.2416	0.2757	−0.0044	0.050*
H1C	0.4058	0.3834	0.0186	0.050*
C2	0.2577 (4)	0.2497 (4)	0.12936 (18)	0.0384 (8)
H2A	0.3576	0.2670	0.1248	0.058*
H2B	0.1883	0.1538	0.1116	0.058*
H2C	0.2360	0.2518	0.1743	0.058*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr1	0.0165 (4)	0.0165 (4)	0.0311 (6)	0.00824 (19)	0.000	0.000
Cl1	0.0245 (6)	0.0245 (6)	0.0480 (11)	0.0123 (3)	0.000	0.000
Cl2	0.0421 (6)	0.0421 (6)	0.0405 (9)	0.0211 (3)	0.000	0.000
S1	0.0221 (4)	0.0207 (4)	0.0346 (5)	0.0099 (3)	−0.0004 (3)	−0.0004 (3)
O1	0.0202 (10)	0.0222 (10)	0.0374 (12)	0.0096 (9)	−0.0015 (8)	−0.0045 (8)
C1	0.0339 (17)	0.0279 (16)	0.0331 (17)	0.0111 (13)	0.0028 (13)	−0.0017 (13)
C2	0.045 (2)	0.0278 (16)	0.044 (2)	0.0196 (15)	−0.0007 (16)	0.0063 (14)

Geometric parameters (Å, º)

Cr1—O1^i	1.972 (2)	S1—C1	1.772 (3)
Cr1—O1^ii	1.971 (2)	C1—H1A	0.9800
Cr1—O1^iii	1.971 (2)	C1—H1B	0.9800
Cr1—O1	1.970 (2)	C1—H1C	0.9800
Cr1—O1^iv	1.971 (2)	C2—H2A	0.9800
Cr1—O1^v	1.971 (2)	C2—H2B	0.9800
S1—O1	1.542 (2)	C2—H2C	0.9800
S1—C2	1.770 (3)
O1^i—Cr1—O1^ii	180.0	O1—S1—C1	102.86 (14)
O1^i—Cr1—O1^iii	91.81 (9)	C2—S1—C1	98.87 (17)
O1^ii—Cr1—O1^iii	88.19 (9)	S1—O1—Cr1	121.86 (12)
O1^i—Cr1—O1	91.81 (9)	S1—C1—H1A	109.5
O1^ii—Cr1—O1	88.19 (9)	S1—C1—H1B	109.5
O1^iii—Cr1—O1	91.81 (9)	H1A—C1—H1B	109.5
O1^i—Cr1—O1^iv	88.19 (9)	S1—C1—H1C	109.5
O1^ii—Cr1—O1^iv	91.81 (9)	H1A—C1—H1C	109.5
O1^iii—Cr1—O1^iv	180.0	H1B—C1—H1C	109.5
O1—Cr1—O1^iv	88.19 (9)	S1—C2—H2A	109.5
O1^i—Cr1—O1^v	88.19 (9)	S1—C2—H2B	109.5
O1^ii—Cr1—O1^v	91.81 (9)	H2A—C2—H2B	109.5
O1^iii—Cr1—O1^v	88.19 (9)	S1—C2—H2C	109.5
O1—Cr1—O1^v	179.999 (1)	H2A—C2—H2C	109.5
O1^iv—Cr1—O1^v	91.81 (9)	H2B—C2—H2C	109.5
O1—S1—C2	104.46 (15)
C2—S1—O1—Cr1	−112.64 (17)	O1^ii—Cr1—O1—S1	140.87 (18)
C1—S1—O1—Cr1	144.52 (16)	O1^iii—Cr1—O1—S1	−131.00 (10)
O1^i—Cr1—O1—S1	−39.13 (18)	O1^iv—Cr1—O1—S1	49.00 (10)

Symmetry codes: (i) −x+y, −x+1, z; (ii) x−y+2/3, x+1/3, −z+1/3; (iii) −y+1, x−y+1, z; (iv) y−1/3, −x+y+1/3, −z+1/3; (v) −x+2/3, −y+4/3, −z+1/3.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···Cl1	0.98	2.75	3.647 (3)	153
C1—H1A···Cl2^vi	0.98	2.64	3.614 (4)	176

Symmetry code: (vi) x+1/3, y+2/3, z−1/3.