Hexa­kis­(di­methyl sulfoxide-κO)zinc(II) poly­iodide

The title compound, [Zn{(CH₃)₂SO}₆]I₄, is a one-dimensional supra­molecular polymer along a threefold rotation axis of the space group. It is built up from discrete [Zn{(CH₃)₂SO}₆]²⁺ units connected through non-classical hydrogen bonds to linear I₄²⁻ polyiodide anions (C—H⋯I = 3.168 Å). The Zn^II ion in the cation has an octa­hedral coordination geometry, with all six Zn—O bond lengths being equivalent, at 2.111 (4) Å. The linear polyiodide anion contains a neutral I₂ mol­ecule weakly coordinated to two iodide ions.

Related literature

For related structures, see Garzón-Tovar et al. (2013); Long et al. (1999); Tkachev et al. (1994). For supra­molecular polymers formed by non-classical hydrogen bonds, see: Fromm (2001); Huang & Scherman (2012); Youm et al. (2006). For polyiodide compounds, see: Svensson & Kloo (2003).

Experimental

Crystal data

• [Zn(C₂H₆OS)₆]I₄

• M_r = 1041.79

• Triggonal,

• a = 11.8399 (7) Å

• c = 19.7110 (12) Å

• V = 2393.0 (2) ų

• Z = 3

• Mo Kα radiation

• μ = 5.06 mm⁻¹

• T = 298 K

• 0.60 × 0.40 × 0.40 mm

Data collection

• Nonius KappaCCD diffractometer

• Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997) T_min = 0.126, T_max = 0.132

• 3127 measured reflections

• 1512 independent reflections

• 1251 reflections with > 2.0σ(I)

• R_int = 0.036

Refinement

• R[F² > 2σ(F²)] = 0.047

• wR(F²) = 0.104

• S = 1.17

• 1512 reflections

• 48 parameters

• H-atom parameters constrained

• Δρ_max = 1.00 e Å⁻³

• Δρ_min = −1.23 e Å⁻³

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010).

Supporting information

S1. Comment

Supramolecular polymers are defined as polymeric systems that extend beyond the molecule by a process of self-assembly between monomer units directed by noncovalent interactions (Huang & Scherman, 2012). These noncovalent forces, such as hydrogen bonding, coordination bonds, π–π stacking and electrostatic forces act as driving forces to construct a well defined supramolecular architectures (Fromm, 2001); however, there are a few examples where non-classical hydrogen bonds such as C—H···I are used to construct these structures (Youm et al., 2006). Previous studies have suggested that a coordination complex with DMSO such as [Cu(DMSO)₆]²⁺ acts as monomeric units connected through a self-assembly process with tetraiodide ions driven by weak non-classical hydrogen bonds C—H···I to form a one-dimensional supramolecular polymer (Garzón-Tovar et al., 2013). Herein we report the synthesis and structural characterization of a new supramolecular polymer.

In the title compound, [Zn{(CH₃)₂SO}₆]I₄, the Zn(II) ion is located on a 3-fold inversion axis being coordinated by six equidistant oxygen-bonded dimethyl sulfoxide ligands (Fig. 1). The Zn—O bond distances in the [Zn(DMSO)₆]²⁺ complex are 2.111 (4) Å and 87.28 (16), 92.71 (16) ° bond angles. The linear tetraiodide chain presents a neutral I—I molecule with bond distance of 2.8417 (18) Å, weakly coordinated with two iodide (I^-) anions (bond distance 3.335 (1) Å). This result is in agreement with other studies, where the I₄^2- correspond to interaction of two I^- anions with one I₂ molecule (I^δ-(I—I)I^δ-) (Long et al.,1999). The two end-iodide anions build up three weak hydrogen bonds to the hydrogen atoms of the methyl groups with distances of 3.167 Å (Fig. 2) to form a one-dimensional supramolecular polymer.

Related literature

For related structures, see Garzón-Tovar et al. (2013); Long et al. (1999); Tkachev et al. (1994). For supramolecular polymers formed by non-classical hydrogen bonds, see: Fromm (2001); Huang & Scherman (2012); Youm et al. (2006). For polyiodide compounds, see: Svensson & Kloo (2003).

S2. Experimental

Zinc (II) chloride (1.1404 g, 8.3659 mmol) was added to a DMSO (16.506 g, 211.26 mmol) and distilled water (0.199 g, 11.1 mmol) solution. After colorless mixture was ultrasonicated for 20 min, CH₃I (3.420 g, 24.09 mmol) was added, and ultrasonication was continued for an additional 20 min. The resulting yellow solution was kept at 20°C for 8 d, with continuous agitation. The mixture was filtered, and the filtrate was refrigerated at 4°C for 30 d, after which blue crystals with a metallic luster formed. The crystals of [Zn{(CH₃)₂SO}₆]I₄ were filtered and dried under vacuum. The yield obtained was 0.3231 g.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures

	Fig. 1. Molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms represented by small spheres of arbitrary radii.
	Fig. 2. The crystal packing of the title compound viewed along the b axis. The C—H···I hydrogen bonds are shown as dashed lines.

Hexakis(dimethyl sulfoxide-κO)zinc(II) polyiodide

Crystal data

[Zn(C2H6OS)6]I4	Dx = 2.169 Mg m^−3
Mr = 1041.79	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 3127 reflections
Hall symbol: -R 3	θ = 3–30°
a = 11.8399 (7) Å	µ = 5.06 mm^−1
c = 19.7110 (12) Å	T = 298 K
V = 2393.0 (2) Å^3	Plate, 1orange
Z = 3	0.60 × 0.40 × 0.40 mm
F(000) = 1482

Data collection

Nonius KappaCCD diffractometer	1251 reflections with > 2.0σ(I)
Graphite 002 monochromator	Rint = 0.036
ω scans	θmax = 30.0°, θmin = 2.9°
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	h = 0→16
Tmin = 0.126, Tmax = 0.132	k = −14→0
3127 measured reflections	l = −27→27
1512 independent reflections

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	1/[σ^2(Fo^2) + (0.P)^2 + 55.1589P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.047	(Δ/σ)max < 0.001
wR(F^2) = 0.104	Δρmax = 1.00 e Å^−3
S = 1.17	Δρmin = −1.23 e Å^−3
1512 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008)
48 parameters	Extinction coefficient: 0.30E-02
0 restraints

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. Outlier data were removed using a local program based on the method of Prince and Nicholson.

Refinement on F² for ALL reflections except for 0 with very negative F² or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating R_factor_obs 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
I1	0.6667	0.3333	0.59206 (4)	0.0430 (3)
I2	0.0000	0.0000	0.42791 (5)	0.0466 (3)
Zn1	0.6667	0.3333	0.3333	0.0258 (3)
S1	0.62508 (13)	0.54407 (13)	0.40794 (8)	0.0316 (3)
O1	0.7243 (4)	0.5025 (4)	0.3922 (2)	0.0324 (9)
C1	0.6592 (7)	0.6747 (6)	0.3515 (4)	0.0423 (15)
C2	0.6825 (8)	0.6355 (7)	0.4845 (3)	0.0478 (16)
H1A	0.7491	0.7411	0.3559	0.063*
H1B	0.6045	0.7105	0.3625	0.063*
H1C	0.6425	0.6428	0.3057	0.063*
H2A	0.6836	0.5804	0.5199	0.072*
H2B	0.6256	0.6680	0.4972	0.072*
H2C	0.7691	0.7074	0.4776	0.072*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.0445 (3)	0.0445 (3)	0.0400 (4)	0.02223 (15)	0.0000	0.0000
I2	0.0356 (3)	0.0356 (3)	0.0688 (6)	0.01778 (14)	0.0000	0.0000
Zn1	0.0221 (4)	0.0221 (4)	0.0331 (8)	0.0111 (2)	0.0000	0.0000
S1	0.0264 (6)	0.0250 (6)	0.0409 (8)	0.0110 (5)	0.0057 (5)	−0.0013 (5)
O1	0.033 (2)	0.0274 (18)	0.040 (2)	0.0174 (16)	0.0017 (17)	−0.0037 (16)
C1	0.049 (4)	0.038 (3)	0.049 (4)	0.028 (3)	0.005 (3)	0.008 (3)
C2	0.066 (5)	0.044 (4)	0.037 (3)	0.030 (4)	0.003 (3)	−0.009 (3)

Geometric parameters (Å, º)

I2—I2^i	2.8417 (18)	S1—C1	1.780 (6)
Zn1—O1^ii	2.111 (4)	S1—C2	1.782 (7)
Zn1—O1^iii	2.111 (4)	C1—H1A	0.9600
Zn1—O1^iv	2.111 (4)	C1—H1B	0.9600
Zn1—O1	2.111 (4)	C1—H1C	0.9600
Zn1—O1^v	2.111 (4)	C2—H2A	0.9600
Zn1—O1^vi	2.111 (4)	C2—H2B	0.9600
S1—O1	1.515 (4)	C2—H2C	0.9600
O1^ii—Zn1—O1^iii	179.9980 (10)	O1—S1—C2	104.4 (3)
O1^ii—Zn1—O1^iv	87.29 (16)	C1—S1—C2	98.6 (3)
O1^iii—Zn1—O1^iv	92.71 (16)	S1—O1—Zn1	119.0 (2)
O1^ii—Zn1—O1	87.29 (16)	S1—C1—H1A	109.50
O1^iii—Zn1—O1	92.71 (16)	S1—C1—H1B	109.50
O1^iv—Zn1—O1	92.71 (16)	H1A—C1—H1B	109.50
O1^ii—Zn1—O1^v	92.71 (16)	S1—C1—H1C	109.50
O1^iii—Zn1—O1^v	87.29 (16)	H1A—C1—H1C	109.50
O1^iv—Zn1—O1^v	179.9980 (10)	H1B—C1—H1C	109.50
O1—Zn1—O1^v	87.29 (16)	S1—C2—H2A	109.50
O1^ii—Zn1—O1^vi	92.71 (16)	S1—C2—H2B	109.50
O1^iii—Zn1—O1^vi	87.29 (16)	H2A—C2—H2B	109.50
O1^iv—Zn1—O1^vi	87.29 (16)	S1—C2—H2C	109.50
O1—Zn1—O1^vi	180.00	H2A—C2—H2C	109.50
O1^v—Zn1—O1^vi	92.71 (15)	H2B—C2—H2C	109.50
O1—S1—C1	106.1 (3)
C1—S1—O1—Zn1	−101.8 (3)	O1^iv—Zn1—O1—S1	−48.4 (3)
C2—S1—O1—Zn1	154.6 (3)	O1^v—Zn1—O1—S1	131.6 (3)
O1^ii—Zn1—O1—S1	38.74 (19)	O1^vi—Zn1—O1—S1	112 (10)
O1^iii—Zn1—O1—S1	−141.26 (19)

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