Crystal structure of cis-tetra­aqua­di­chlorido­cobalt(II) sulfolane disolvate

In the title compound, [CoCl₂(H₂O)₄]·2C₄H₈SO₂, the Co^II cation is located on the twofold rotation axis and is coordinated by four water mol­ecules and two adjacent chloride ligands in a slightly distorted octa­hedral coordination environment. The cisoid angles are in the range 83.27 (5)–99.66 (2)°. The three transoid angles deviate significantly from the ideal linear angle. The crystal packing can be described as a linear arrangement of complex units along c formed by bifurcated O—H⋯Cl hydrogen bonds between two water mol­ecules from one complex unit towards one chloride ligand of the neighbouring complex. Two solvent mol­ecules per complex are attached to this infinite chain via O—H⋯O hydrogen bonds in which water mol­ecules act as the hydrogen-bond donor and sulfolane O atoms as the hydrogen-bond acceptor sites.

1. Related literature

For structures where the Co^II atom exhibits an octahedral geometry and is coordinated by water molecules, see: Waizumi et al. (1990); Sarangarajan et al. (2008). For potential applications of organic–inorganic hybrid compounds, see: Al-Ktaifani & Rukiah (2011). For related structures, see: Bouacida et al. (2005, 2013); Sahbani et al. (2014).

2. Experimental

2.1. Crystal data

• [CoCl₂(H₂O)₄]·2C₄H₈O₂S

• M_r = 442.22

• Monoclinic, C 2/c

• a = 20.062 (2) Å

• b = 9.4284 (10) Å

• c = 10.5882 (13) Å

• β = 118.734 (5)°

• V = 1756.2 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 1.55 mm⁻¹

• T = 295 K

• 0.21 × 0.15 × 0.09 mm

2.2. Data collection

• Bruker APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2002) T_min = 0.649, T_max = 0.748

• 20238 measured reflections

• 5090 independent reflections

• 3409 reflections with I > 2σ(I)

• R_int = 0.061

2.3. Refinement

• R[F² > 2σ(F²)] = 0.043

• wR(F²) = 0.129

• S = 1.01

• 5090 reflections

• 108 parameters

• 4 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.90 e Å⁻³

• Δρ_min = −1.44 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W⋯Cl1^i	0.77 (3)	2.44 (3)	3.1885 (15)	165 (3)
O1W—H2W⋯O11	0.81 (2)	1.99 (2)	2.782 (2)	165 (2)
O2W—H3W⋯Cl1^ii	0.83 (2)	2.41 (2)	3.2289 (16)	171 (2)
O2W—H4W⋯O12	0.79 (3)	2.05 (3)	2.835 (2)	174 (3)
Symmetry codes: (i) -x+1, -y+1, -z; (ii) .

Data collection: APEX2 (Bruker, 2011); cell refinement: SAINT (Bruker, 2011); data reduction: SAINT; program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 2012).

Supporting information

S1. Comment

Organic-inorganic hybrid salts have received considerable attention because of their potential applications in analytical, material and supramolecular chemistry (Al-Ktaifani et al., 2011; Bouacida et al. 2005, 2013; Sahbani et al., 2014). In this work, we report the preparation and the structural investigation of [Co(H₂O)₄Cl₂] × 2 C₄H₈SO₂. Since the central cobalt the Co^II cation is located on the twofold rotation axis the asymmetric unit of (I) consists of one one half of the complex unit and one molecule of sulfolane (Figure 1).

The structure of the compound consists of discrete tetraaquadichlorocobalt(II) complexes stacked in chains parallel to the c axis. The Co^II cation is coordinated by four water molecules and two adjacent chloride ligands in a slightly distorted octahedral geometry. The two Co—Cl distances are 2.510 (6) Å and the Co—O distances are between 2.165 (3) and 2.243 (3) Å in good agreement with that found in mineral compound CoCl₂O₄H₈ (Waizumi et al., 1990) and in the coordination compound [CoCl₂(H₂O)₄]C₄H₆N₂O₂ (Sarangarajan et al., 2008). Cisoid angles around Co atom are in the range of 83.27 (5)° to 99.66 (2)°. In the organic molecule, the S atom is tetrahedrally coordinated by two O and two C atoms. The three bonds C—C are in the range 1.516 (2)–1,531 (3) Å. In the crystal, molecules are linked by O—H···O and O—H···Cl hydrogen bonds forming chains along [001] (Figure 2). The crystal packing can be described as a linear arrangement of complex units along c formed by bifurcated O–H···Cl hydrogen bonds between two water molecules from one complex unit towards one chloride ligand of the neighboring complex. Two solvent molecules per complex are attached to this infinite chain via O–H···O hydrogen bonds in which water molecules act as the hydrogen bond donor and sulfolane oxygen atoms as the hydrogen bond acceptor sites.

Related literature

For the environment of Co^II, see: Waizumi et al. (1990); Sarangarajan et al. (2008). For potential applications of organic–inorganic hybrid compounds, see: Al-Ktaifani & Rukiah (2011); Bouacida et al. (2005, 2013); Sahbani et al. (2014).

S2. Experimental

A solution of CoCl₂ × 2 H₂O (34 mg, 0.2 mmol) in water (10 ml) was added dropwise to a solution of sulfolane (24 mg, 0.2 mmol) in water (10 ml). The mixture was then refluxed with stirring for 3 h and the resulting solution was left to stand at room temperature. After several days, blue crystals were obtained and dried under vacuum (yield: 55%).

S3. Refinement

All non-H atoms were refined with anisotropic displacement parameters. Approximate positions for all H atoms were first obtained from the difference electron density map. However, the H atoms were situated into idealized positions and the H-atoms have been refined within the riding atom approximation with C—H = 0.93 Å and U_iso = 1.2U_eq(C) except for H atoms of water molecules, which were refined isotropically using the following restraints: O—H = 0.84 (2) Å, H···H = 1.45 (2) Å and U_iso = 1.5U_eq(O).

Computing details

Data collection: APEX2 (Bruker, 2011); cell refinement: SAINT (Bruker, 2011); data reduction: SAINT (Bruker, 2011); program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures

	Fig. 1. Molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level. Only the asymmetric unit is labelled. H atoms are represented as small spheres of arbitrary radii.
	Fig. 2. Packing diagram of (I) showing the infinite chains of complex units and solvent molecule along the c axis.

cis-Tetraaquadichloridocobalt(II) sulfolane disolvate

Crystal data

[CoCl2(H2O)4]·2C4H8O2S	F(000) = 916
Mr = 442.22	Dx = 1.673 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 5148 reflections
a = 20.062 (2) Å	θ = 2.5–35.1°
b = 9.4284 (10) Å	µ = 1.55 mm^−1
c = 10.5882 (13) Å	T = 295 K
β = 118.734 (5)°	Prism, blue
V = 1756.2 (3) Å^3	0.21 × 0.15 × 0.09 mm
Z = 4

Data collection

Bruker APEXII diffractometer	5090 independent reflections
Radiation source: sealed tube	3409 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
ϕ and ω scans	θmax = 39.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −34→35
Tmin = 0.649, Tmax = 0.748	k = −16→16
20238 measured reflections	l = −18→14

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.129	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0666P)^2] where P = (Fo^2 + 2Fc^2)/3
5090 reflections	(Δ/σ)max = 0.007
108 parameters	Δρmax = 0.90 e Å^−3
4 restraints	Δρmin = −1.44 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
Co1	0.5	0.47467 (3)	0.25	0.01473 (8)
S1	0.76287 (2)	0.53220 (4)	0.58938 (4)	0.01334 (9)
Cl1	0.43290 (2)	0.30294 (4)	0.04608 (4)	0.01647 (9)
O1W	0.59916 (7)	0.49821 (15)	0.22088 (14)	0.0177 (2)
H1W	0.5953 (15)	0.556 (2)	0.168 (2)	0.027*
H2W	0.6412 (11)	0.483 (3)	0.288 (2)	0.027*
O2W	0.54617 (7)	0.65037 (13)	0.41295 (13)	0.0155 (2)
H3W	0.5200 (12)	0.669 (3)	0.452 (2)	0.023*
H4W	0.5887 (12)	0.631 (3)	0.467 (3)	0.023*
C3	0.90875 (11)	0.5145 (2)	0.7520 (3)	0.0298 (5)
H3A	0.955	0.5538	0.8296	0.036*
H3B	0.9206	0.4724	0.6815	0.036*
C4	0.84886 (10)	0.6288 (2)	0.6830 (2)	0.0240 (4)
H4A	0.8584	0.686	0.6172	0.029*
H4B	0.8475	0.69	0.7554	0.029*
C1	0.79391 (13)	0.3742 (2)	0.6942 (2)	0.0293 (4)
H1A	0.7618	0.3529	0.737	0.035*
H1B	0.7924	0.2945	0.635	0.035*
C2	0.87487 (14)	0.4035 (3)	0.8102 (3)	0.0386 (6)
H2A	0.9047	0.317	0.8342	0.046*
H2B	0.8752	0.4386	0.8966	0.046*
O12	0.70254 (8)	0.60180 (16)	0.60336 (16)	0.0245 (3)
O11	0.74827 (8)	0.50189 (17)	0.44424 (16)	0.0273 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.01483 (14)	0.01815 (15)	0.01223 (15)	0	0.00731 (12)	0
S1	0.01081 (15)	0.01611 (17)	0.01057 (17)	−0.00112 (12)	0.00313 (13)	0.00104 (12)
Cl1	0.02063 (18)	0.01729 (17)	0.01137 (16)	−0.00469 (13)	0.00760 (14)	−0.00251 (13)
O1W	0.0121 (5)	0.0302 (7)	0.0117 (5)	0.0022 (4)	0.0064 (4)	0.0051 (5)
O2W	0.0149 (5)	0.0186 (5)	0.0130 (5)	−0.0020 (4)	0.0067 (4)	−0.0022 (4)
C3	0.0136 (7)	0.0444 (12)	0.0283 (11)	0.0051 (7)	0.0074 (7)	−0.0038 (9)
C4	0.0173 (7)	0.0219 (8)	0.0277 (9)	−0.0067 (6)	0.0068 (7)	−0.0036 (7)
C1	0.0397 (12)	0.0158 (8)	0.0332 (11)	0.0009 (7)	0.0182 (10)	0.0080 (7)
C2	0.0326 (11)	0.0517 (14)	0.0278 (11)	0.0189 (10)	0.0115 (9)	0.0219 (10)
O12	0.0160 (6)	0.0326 (7)	0.0230 (7)	0.0034 (5)	0.0079 (5)	−0.0044 (5)
O11	0.0188 (6)	0.0506 (9)	0.0112 (6)	−0.0003 (6)	0.0060 (5)	−0.0021 (6)

Geometric parameters (Å, º)

Co1—O1W	2.1660 (13)	O2W—H4W	0.79 (2)
Co1—O1W^i	2.1660 (13)	C3—C4	1.515 (3)
Co1—O2W	2.2455 (12)	C3—C2	1.529 (4)
Co1—O2W^i	2.2455 (12)	C3—H3A	0.97
Co1—Cl1	2.5102 (5)	C3—H3B	0.97
Co1—Cl1^i	2.5102 (5)	C4—H4A	0.97
S1—O12	1.4456 (14)	C4—H4B	0.97
S1—O11	1.4478 (16)	C1—C2	1.518 (3)
S1—C4	1.7730 (18)	C1—H1A	0.97
S1—C1	1.7820 (19)	C1—H1B	0.97
O1W—H1W	0.758 (16)	C2—H2A	0.97
O1W—H2W	0.812 (17)	C2—H2B	0.97
O2W—H3W	0.830 (16)
O1W—Co1—O1W^i	168.24 (8)	H3W—O2W—H4W	115 (2)
O1W—Co1—O2W	88.05 (5)	C4—C3—C2	106.16 (18)
O1W^i—Co1—O2W	83.27 (5)	C4—C3—H3A	110.5
O1W—Co1—O2W^i	83.27 (5)	C2—C3—H3A	110.5
O1W^i—Co1—O2W^i	88.05 (5)	C4—C3—H3B	110.5
O2W—Co1—O2W^i	84.92 (7)	C2—C3—H3B	110.5
O1W—Co1—Cl1	95.34 (4)	H3A—C3—H3B	108.7
O1W^i—Co1—Cl1	92.24 (4)	C3—C4—S1	103.73 (13)
O2W—Co1—Cl1	171.61 (4)	C3—C4—H4A	111
O2W^i—Co1—Cl1	87.85 (3)	S1—C4—H4A	111
O1W—Co1—Cl1^i	92.24 (4)	C3—C4—H4B	111
O1W^i—Co1—Cl1^i	95.34 (4)	S1—C4—H4B	111
O2W—Co1—Cl1^i	87.85 (3)	H4A—C4—H4B	109
O2W^i—Co1—Cl1^i	171.61 (4)	C2—C1—S1	105.63 (15)
Cl1—Co1—Cl1^i	99.66 (2)	C2—C1—H1A	110.6
O12—S1—O11	116.50 (9)	S1—C1—H1A	110.6
O12—S1—C4	110.32 (9)	C2—C1—H1B	110.6
O11—S1—C4	109.92 (10)	S1—C1—H1B	110.6
O12—S1—C1	112.01 (10)	H1A—C1—H1B	108.7
O11—S1—C1	109.14 (10)	C1—C2—C3	107.97 (17)
C4—S1—C1	97.26 (10)	C1—C2—H2A	110.1
Co1—O1W—H1W	114 (2)	C3—C2—H2A	110.1
Co1—O1W—H2W	120 (2)	C1—C2—H2B	110.1
H1W—O1W—H2W	118 (3)	C3—C2—H2B	110.1
Co1—O2W—H3W	114.7 (17)	H2A—C2—H2B	108.4
Co1—O2W—H4W	106.8 (18)
C2—C3—C4—S1	−42.0 (2)	O11—S1—C1—C2	115.94 (17)
O12—S1—C4—C3	140.20 (15)	C4—S1—C1—C2	1.88 (19)
O11—S1—C4—C3	−89.99 (17)	S1—C1—C2—C3	−27.0 (2)
C1—S1—C4—C3	23.45 (17)	C4—C3—C2—C1	45.6 (3)
O12—S1—C1—C2	−113.53 (17)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···Cl1^ii	0.77 (3)	2.44 (3)	3.1885 (15)	165 (3)
O1W—H2W···O11	0.81 (2)	1.99 (2)	2.782 (2)	165 (2)
O2W—H3W···Cl1^iii	0.83 (2)	2.41 (2)	3.2289 (16)	171 (2)
O2W—H4W···O12	0.79 (3)	2.05 (3)	2.835 (2)	174 (3)

Symmetry codes: (ii) −x+1, −y+1, −z; (iii) x, −y+1, z+1/2.