2-Hy­dr­oxy­methyl-1,3-di­methyl-1H-imidazol-3-ium triiodide

The crystal packing of the title salt, C₆H₁₁N₂O⁺·I₃⁻, can be described as consisting of alternating layers of cations and anions parallel to the (100) plane along the a-axis direction. The components are linked by O—H⋯I, C—H⋯I and C—H⋯O interactions, generating a three-dimensional network. The O atom deviates from the imidazol ring by 0.896 (2) Å.

Related literature

For the importance of heterocyclic compounds and their applications, see: Pandey et al. (2009); Nasser (2000). For the biological activity of imidazole and imidazolium derivatives, see: Ucucu et al. (2001); Dominianni et al. (1989); Ozkay et al. (2010). For our previous work on imidazole derivatives, see: Bahnous et al. (2012); Zama et al. (2013); Chelghoum et al. (2011).

Experimental

Crystal data

• C₆H₁₁N₂O⁺·I₃⁻

• M_r = 507.87

• Monoclinic, P 2₁ /c

• a = 7.1647 (8) Å

• b = 15.5586 (19) Å

• c = 11.3201 (13) Å

• β = 96.026 (7)°

• V = 1254.9 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 7.44 mm⁻¹

• T = 150 K

• 0.24 × 0.03 × 0.02 mm

Data collection

• Bruker APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2002) T_min = 0.781, T_max = 1.000

• 7061 measured reflections

• 2222 independent reflections

• 2104 reflections with I > 2σ(I)

• R_int = 0.022

Refinement

• R[F² > 2σ(F²)] = 0.015

• wR(F²) = 0.034

• S = 1.15

• 2222 reflections

• 112 parameters

• H-atom parameters constrained

• Δρ_max = 0.45 e Å⁻³

• Δρ_min = −0.47 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯I1^i	0.82	3.03	3.741 (2)	146
C1—H1B⋯I3^ii	0.97	3.05	3.924 (3)	151
C4—H4⋯O1^iii	0.93	2.60	3.421 (4)	148
Symmetry codes: (i) x+1, y, z; (ii) ; (iii) .

Data collection: APEX2 (Bruker, 2006); cell refinement: SMART (Bruker, 2006); data reduction: SMART; 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) and CRYSCAL (T. Roisnel, local program).

Supporting information

S1. Comment

Heterocyclic compounds have so far been synthesized mainly due to the wide range of biological activities. At present, the role of heterocyclic compounds has become increasingly important in designing new class of structural entities of medicinal importance (Pandey et al., 2009; Nasser, 2000). Imidazole is a nitrogen containing heterocyclic ring which possesses biological and pharmaceutical importance (Ozkay, et al., 2010). It forms the main structure of some well known components of human organisms, i.e. the amino acid histidine, Vit-B12, a component of DNA base structure and purines, histamine and biotin (Ucucu, et al., 2001). In other hand, imidazolium salts are known for the wide range of their biological activity. A large variety of these salts have been used as anti-inflammatory, antibacterial, antifungal and thromboxane synthetase inhibitior (Dominianni et al., 1989). In continuation of our studies on imidazole derivatives (Bahnous et al., 2012; Zama et al., 2013 and Chelghoum et al., 2011). We report herein the synthesis and crystal structure of a new imidazolium salt, I, bearing two methyl groups at C-1 and C-3 positions, a hydroxymethyl at C-2 and a triiodide anion that balance the charge.

The molecular geometry and the atom-numbering scheme of (I) are shown in Fig. 1. The asymmetric unit of title molecule, C₆H₁₁N₂O, I₃, contains a 1,3-dimethyl-2-hydroxymethylidazolium cation and triiodide anion. The crystal packing can be described as alternating layers parallel to the (100) plane along the a axis, where triiodide anion is located in these layers (Fig. 2) and they are linked together by O—H···I, C—H···I and C—H···O intermolecular hydrogen bonds As shown in the Figure 2, the imidazol rings of the symmetry related layers are intercalated, however the centroid to centroid distance between the imidazol rings are too long (5.3400 (19) and 5.6641 (19) Å) for considering π-π interactions. These interaction bonds link the molecules within the layers and also link the layers together, reinforcing the cohesion of the ionic structure. Hydrogen-bonding parameters are listed in table 1.

Related literature

For the importance of heterocyclic compounds and their applications, see: Pandey et al. (2009); Nasser (2000). For the biological activity of imidazole and imidazolium derivatives, see: Ucucu et al. (2001); Dominianni et al. (1989); Ozkay et al. (2010). For our previous work on imidazole derivatives, see: Bahnous et al. (2012); Zama et al. (2013); Chelghoum et al. (2011).

S2. Experimental

The treatment of 1,3-dimethyl-2-hydroxymethylimidazolium iodide (Chelghoum et al., 2011) with diluted sulfuric acid solution, during ten days in opened flask for slow evaporation, gave the title compound as a brown crystals. The crystals are filtered off and washed with water. Suitable crystal of compound (I) was selected and X-ray crystallographic analysis confirmed the structural assignment (Fig. 1).

S3. Refinement

Approximate positions for all the 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. The applied constraints were as follow: C_aryl—H_aryl = 0.93 Å; C_methylene—H_methylene = 0.97 Å; C_methyl—H_methyl = 0.96 Å and C_hydroxy—H_hydroxy = 0.82 Å; The idealized methyl group was allowed to rotate about the C—C bond during the refinement by application of the command AFIX 137 in SHELXL97 (Sheldrick, 2008). U_iso(H_methyl or _hydroxy) = 1.5U_eq(C_methyl or _hydroxy) or U_iso(H_aryl or H_methylene) = 1.2 U_eq(C_aryl or C_methylene).

Computing details

Data collection: APEX2 (Bruker, 2006); cell refinement: SMART (Bruker, 2006); data reduction: SMART (Bruker, 2006); 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) and CRYSCAL (T. Roisnel, local program).

Figures

	Fig. 1. The molecular geometry of (I) with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radius.
	Fig. 2. Alternating layers of (I) viewed down the c axis showing hydrgen bond as dashed line.

2-Hydroxymethyl-1,3-dimethyl-1H-imidazol-3-ium triiodide

Crystal data

C6H11N2O^+·I3^−	F(000) = 912
Mr = 507.87	Dx = 2.688 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5058 reflections
a = 7.1647 (8) Å	θ = 2.2–25.1°
b = 15.5586 (19) Å	µ = 7.44 mm^−1
c = 11.3201 (13) Å	T = 150 K
β = 96.026 (7)°	Stick, brown
V = 1254.9 (3) Å^3	0.24 × 0.03 × 0.02 mm
Z = 4

Data collection

Bruker APEXII diffractometer	2104 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
CCD rotation images, thin slices scans	θmax = 25.1°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −8→8
Tmin = 0.781, Tmax = 1.000	k = −18→18
7061 measured reflections	l = −13→13
2222 independent 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)] = 0.015	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.034	H-atom parameters constrained
S = 1.15	w = 1/[σ^2(Fo^2) + 1.5935P] where P = (Fo^2 + 2Fc^2)/3
2222 reflections	(Δ/σ)max = 0.001
112 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.47 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
I2	0.23583 (2)	0.148350 (12)	0.326494 (15)	0.01269 (6)
I1	0.19816 (3)	−0.006510 (12)	0.171029 (17)	0.01684 (6)
I3	0.25836 (3)	0.297933 (14)	0.474053 (18)	0.02126 (6)
N2	0.7383 (3)	0.17050 (16)	0.3419 (2)	0.0144 (5)
O1	0.8099 (3)	0.15052 (14)	0.09130 (18)	0.0177 (5)
H1	0.9119	0.1286	0.0833	0.027*
N1	0.7438 (3)	0.03209 (16)	0.3568 (2)	0.0141 (5)
C2	0.7275 (4)	0.09763 (19)	0.2795 (3)	0.0132 (6)
C5	0.7344 (4)	−0.0598 (2)	0.3266 (3)	0.0209 (7)
H5A	0.61	−0.0738	0.292	0.031*
H5B	0.7643	−0.0933	0.3972	0.031*
H5C	0.8227	−0.0723	0.2707	0.031*
C6	0.7239 (4)	0.2584 (2)	0.2943 (3)	0.0196 (7)
H6A	0.8421	0.2751	0.2686	0.029*
H6B	0.6918	0.2971	0.3551	0.029*
H6C	0.6285	0.2605	0.2282	0.029*
C3	0.7663 (4)	0.0651 (2)	0.4703 (3)	0.0195 (7)
H3	0.7811	0.0336	0.5405	0.023*
C4	0.7630 (4)	0.1512 (2)	0.4610 (3)	0.0171 (7)
H4	0.7751	0.1904	0.5234	0.021*
C1	0.6972 (4)	0.0911 (2)	0.1468 (3)	0.0160 (6)
H1A	0.7269	0.0332	0.1228	0.019*
H1B	0.566	0.1018	0.1204	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I2	0.01199 (10)	0.01601 (11)	0.01018 (10)	−0.00047 (7)	0.00176 (7)	0.00073 (7)
I1	0.02125 (11)	0.01258 (11)	0.01685 (11)	−0.00009 (8)	0.00283 (8)	−0.00207 (8)
I3	0.02175 (11)	0.02351 (12)	0.01884 (12)	−0.00312 (8)	0.00360 (8)	−0.00943 (8)
N2	0.0138 (12)	0.0121 (13)	0.0176 (14)	0.0021 (10)	0.0039 (10)	0.0011 (11)
O1	0.0196 (10)	0.0200 (12)	0.0144 (11)	−0.0001 (9)	0.0058 (8)	0.0043 (9)
N1	0.0139 (12)	0.0159 (13)	0.0122 (12)	−0.0006 (10)	0.0008 (9)	0.0034 (11)
C2	0.0075 (13)	0.0149 (15)	0.0172 (15)	0.0021 (11)	0.0017 (11)	0.0017 (12)
C5	0.0276 (17)	0.0114 (16)	0.0234 (17)	0.0011 (13)	0.0022 (13)	0.0032 (13)
C6	0.0235 (16)	0.0124 (16)	0.0239 (17)	0.0016 (13)	0.0075 (13)	0.0029 (13)
C3	0.0193 (15)	0.0275 (19)	0.0117 (15)	0.0002 (13)	0.0021 (12)	0.0025 (13)
C4	0.0182 (15)	0.0213 (17)	0.0127 (15)	−0.0006 (13)	0.0054 (12)	−0.0039 (13)
C1	0.0158 (14)	0.0176 (16)	0.0141 (15)	−0.0007 (12)	−0.0004 (11)	0.0042 (13)

Geometric parameters (Å, º)

I2—I3	2.8594 (4)	C5—H5A	0.96
I2—I1	2.9792 (4)	C5—H5B	0.96
N2—C2	1.334 (4)	C5—H5C	0.96
N2—C4	1.374 (4)	C6—H6A	0.96
N2—C6	1.470 (4)	C6—H6B	0.96
O1—C1	1.417 (3)	C6—H6C	0.96
O1—H1	0.82	C3—C4	1.344 (5)
N1—C2	1.341 (4)	C3—H3	0.93
N1—C3	1.377 (4)	C4—H4	0.93
N1—C5	1.470 (4)	C1—H1A	0.97
C2—C1	1.499 (4)	C1—H1B	0.97
I3—I2—I1	178.026 (8)	N2—C6—H6B	109.5
C2—N2—C4	109.2 (3)	H6A—C6—H6B	109.5
C2—N2—C6	126.8 (3)	N2—C6—H6C	109.5
C4—N2—C6	124.0 (3)	H6A—C6—H6C	109.5
C1—O1—H1	109.5	H6B—C6—H6C	109.5
C2—N1—C3	108.6 (3)	C4—C3—N1	107.4 (3)
C2—N1—C5	126.1 (3)	C4—C3—H3	126.3
C3—N1—C5	125.3 (3)	N1—C3—H3	126.3
N2—C2—N1	107.7 (3)	C3—C4—N2	107.1 (3)
N2—C2—C1	125.7 (3)	C3—C4—H4	126.4
N1—C2—C1	126.6 (3)	N2—C4—H4	126.4
N1—C5—H5A	109.5	O1—C1—C2	111.7 (2)
N1—C5—H5B	109.5	O1—C1—H1A	109.3
H5A—C5—H5B	109.5	C2—C1—H1A	109.3
N1—C5—H5C	109.5	O1—C1—H1B	109.3
H5A—C5—H5C	109.5	C2—C1—H1B	109.3
H5B—C5—H5C	109.5	H1A—C1—H1B	107.9
N2—C6—H6A	109.5
C4—N2—C2—N1	0.4 (3)	C2—N1—C3—C4	0.2 (3)
C6—N2—C2—N1	−178.8 (2)	C5—N1—C3—C4	−178.4 (3)
C4—N2—C2—C1	178.8 (3)	N1—C3—C4—N2	0.1 (3)
C6—N2—C2—C1	−0.4 (4)	C2—N2—C4—C3	−0.3 (3)
C3—N1—C2—N2	−0.4 (3)	C6—N2—C4—C3	179.0 (3)
C5—N1—C2—N2	178.2 (2)	N2—C2—C1—O1	44.3 (4)
C3—N1—C2—C1	−178.7 (3)	N1—C2—C1—O1	−137.6 (3)
C5—N1—C2—C1	−0.2 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···I1^i	0.82	3.03	3.741 (2)	146
C1—H1B···I3^ii	0.97	3.05	3.924 (3)	151
C4—H4···O1^iii	0.93	2.60	3.421 (4)	148

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