2-Hy­dr­oxy­methyl-1,3-di­methyl-1H-benzimidazol-3-ium iodide

In the cation of the title compound, C₁₀H₁₃N₂O⁺·I⁻, all non-H atoms, with the exception of the O atom, are essentially coplanar, with a maximum deviation of 0.04 (1) Å. In the crystal, the cations and anions are arranged in layers parallel to (100). The cations are connected to the anions via an O—H⋯I hydrogen bond and there are significant π–π stacking inter­actions between cation layers, with centroid–centroid distances in the range 3.606 (5)–3.630 (5) Å. A weak intra­molecular C—H⋯O hydrogen bond is also observed. The crystal studied was an inversion twin with refined components of 0.52 (5) and 0.48 (5).

Related literature

For applications of this class of compounds, see: Tonelli et al. (2010); Preston (1974); Hazelton et al. (1995); Kucukguzel et al. (2001); Islam et al. (1991); Li et al. (2003); Abboud et al. (2006). For our previous work on imidazole derivatives, see: Bahnous et al. (2012); Zama et al. (2013); Chelghoum et al. (2011).

Experimental

Crystal data

• C₁₀H₁₃N₂O⁺·I⁻

• M_r = 304.12

• Orthorhombic, P 2₁ n b

• a = 6.5690 (7) Å

• b = 10.1342 (10) Å

• c = 16.9357 (19) Å

• V = 1127.4 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 2.81 mm⁻¹

• T = 150 K

• 0.14 × 0.13 × 0.12 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2002) T_min = 0.647, T_max = 0.747

• 10018 measured reflections

• 4002 independent reflections

• 3243 reflections with I > 2σ(I)

• R_int = 0.02

Refinement

• R[F² > 2σ(F²)] = 0.027

• wR(F²) = 0.068

• S = 1.05

• 4002 reflections

• 131 parameters

• 1 restraint

• H-atom parameters constrained

• Δρ_max = 1.34 e Å⁻³

• Δρ_min = −0.72 e Å⁻³

• Absolute structure: Flack (1983), 1518 Friedel pairs

• Absolute structure parameter: 0.48 (5)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯I1^i	0.82	2.66	3.473 (3)	171
C5—H5A⋯O1	0.96	2.52	3.170 (5)	125
Symmetry code: (i) x+1, y, z.

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

Supporting information

S1. Comment

Benzimidazole, is isosteric with indole and purine nuclei, which are present in a number of fundamental cellular components and bioactive compounds. This structural similarity means the benzimidazole molecule is endowed with a variety of interesting biological properties (Kucukguzel, et al., 2001; Islam et al., 1991; Tonelli et al., 2010). Some of these compounds are marketed as antifungal, (Preston, 1974), antihelmintic, (Hazelton et al., 1995). Furthermore, benzimidazole derivatives can be also used as epoxy resin curing agents, catalysts, and metallic surface treatment agents (Li et al., 2003; Abboud et al., 2006). In previous work, we have reported the synthesis and structure determination of some new heterocyclic compounds bearing an imidazole unit (Bahnous et al., 2012; Zama et al., 2013; Chelghoum et al., 2011). Herein, we describe the synthesis and the structure determination of 1,3-dimethyl-2-hydroxymethylbenzimidazolium iodide (I) resulting from the quaternization reaction of 1-methyl-2-hydroxymethylbenzimidazole with methyl iodide.

The molecular structure of (I) is shown in Fig. 1. The asymmetric unit contains a 1,3-dimethyl-2-hydroxymethylbenzimidazolium cation and an iodide anion. All non-H atoms in the cation, with the exception of the O atom, are essentially co-planar with a maximum deviation of 0.04 (1)Å for N1. In the crystal, the cations and anions are arranged in layers parallel to (100) (Fig. 2). The cations are hydrogen bonded to the anions via an O—H···I hydrogen bond and there are significant π—π stacking interactions between cation layers with centroid-centroid distances in the range 3.606 (5) - 3.630 (5)Å.

Related literature

For applications of this class of compounds, see: Tonelli et al. (2010); Preston (1974); Hazelton et al. (1995); Kucukguzel et al. (2001); Islam et al. (1991); Li et al. (2003); Abboud et al. (2006). For our previous work on imidazole derivatives, see: Bahnous et al. (2012); Zama et al. (2013); Chelghoum et al. (2011).

S2. Experimental

To a solution of 1-methyl-2-hydroxymethylbenzimidazole derivatives (10 mmol) in 20 ml of acetonitrile, was added 30 mmol of methyl iodide. The reaction mixture was refluxed. When the reaction was over (TLC), the solvent volume was reduced and the crude product was then filtered off and washed with cold acetonitrile. Suitable crystals for X-ray analysis were obtained by slow evaporation of a water solution of (I).

S3. Refinement

Approximate positions for all H atoms were first obtained from the difference electron density map. However, the H atoms were ultimately placed in idealized positions and treated as riding. The applied constraints were as follows: 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 H_hydroxy) = 1.5U_eq(C_methyl or O_hydroxy) or U_iso(H_aryl or H_methylene) = 1.2 U_eq(C_aryl or C_methylene). The crystal used is an inversion twin with refined components 0.52 (5) and 0.48 (5).

Computing details

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (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 structure of (I) with displacement ellipsoids drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radius. Hydrogen bonds are shown as dashed lines.
	Fig. 2. Alternating layers of (I) viewed along the b axis showing hydrogen bonds as dashed lines.

2-Hydroxymethyl-1,3-dimethyl-1H-benzimidazol-3-ium iodide

Crystal data

C10H13N2O^+·I^−	F(000) = 592
Mr = 304.12	Dx = 1.792 Mg m^−3
Orthorhombic, P21nb	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2bc 2a	Cell parameters from 4274 reflections
a = 6.5690 (7) Å	θ = 2.4–34.0°
b = 10.1342 (10) Å	µ = 2.81 mm^−1
c = 16.9357 (19) Å	T = 150 K
V = 1127.4 (2) Å^3	Cube, colorless
Z = 4	0.14 × 0.13 × 0.12 mm

Data collection

Bruker APEXII CCD diffractometer	3243 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.02
CCD rotation images, thin slices scans	θmax = 34.2°, θmin = 3.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −9→10
Tmin = 0.647, Tmax = 0.747	k = −16→15
10018 measured reflections	l = −26→19
4002 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.027	H-atom parameters constrained
wR(F^2) = 0.068	w = 1/[σ^2(Fo^2) + (0.0263P)^2 + 1.1204P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.003
4002 reflections	Δρmax = 1.34 e Å^−3
131 parameters	Δρmin = −0.72 e Å^−3
1 restraint	Absolute structure: Flack (1983), 1518 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.48 (5)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	1.0638 (4)	0.0386 (3)	0.05918 (17)	0.0303 (8)
N1	0.9055 (15)	0.3459 (2)	0.11990 (13)	0.0203 (5)
N2	0.9033 (12)	0.2982 (2)	−0.00606 (12)	0.0168 (5)
C1	0.893 (2)	0.1018 (3)	0.0837 (2)	0.0284 (9)
C2	0.9025 (18)	0.2473 (2)	0.06700 (14)	0.0192 (5)
C3	0.9014 (18)	0.4343 (2)	−0.00046 (14)	0.0165 (5)
C4	0.9022 (15)	0.4649 (2)	0.07953 (15)	0.0179 (6)
C5	0.9046 (16)	0.2214 (3)	−0.07961 (15)	0.0226 (7)
C6	0.893 (2)	0.3340 (3)	0.20631 (18)	0.0326 (11)
C7	0.901 (2)	0.5947 (2)	0.10657 (18)	0.0239 (6)
C8	0.9001 (18)	0.6923 (2)	0.0495 (2)	0.0277 (7)
C9	0.9004 (16)	0.6620 (3)	−0.03096 (19)	0.0255 (7)
C10	0.9028 (14)	0.5327 (2)	−0.05820 (16)	0.0218 (6)
I1	0.3999 (3)	0.08238 (2)	0.21526 (1)	0.0330 (1)
H1	1.15370	0.04750	0.09236	0.0454*
H1A	0.77590	0.06427	0.05712	0.0341*
H1B	0.87606	0.08812	0.13999	0.0341*
H5A	0.98363	0.14266	−0.07223	0.0339*
H5B	0.76764	0.19799	−0.09352	0.0339*
H5C	0.96352	0.27334	−0.12114	0.0339*
H6A	0.83795	0.24932	0.21993	0.0487*
H6B	1.02677	0.34281	0.22861	0.0487*
H6C	0.80648	0.40223	0.22679	0.0487*
H7	0.90136	0.61465	0.16017	0.0287*
H8	0.89907	0.78024	0.06512	0.0333*
H9	0.89902	0.73060	−0.06745	0.0306*
H10	0.90517	0.51273	−0.11180	0.0262*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0335 (14)	0.0250 (11)	0.0324 (14)	0.0107 (11)	−0.0066 (12)	−0.0073 (10)
N1	0.0282 (11)	0.0161 (8)	0.0166 (9)	−0.002 (3)	0.000 (4)	−0.0013 (7)
N2	0.0179 (9)	0.0168 (8)	0.0158 (9)	−0.011 (2)	0.001 (3)	−0.0022 (7)
C1	0.045 (2)	0.0144 (10)	0.0258 (13)	0.009 (3)	0.004 (4)	0.0015 (9)
C2	0.0215 (10)	0.0150 (8)	0.0210 (10)	0.003 (3)	0.003 (5)	−0.0004 (8)
C3	0.0142 (8)	0.0155 (9)	0.0197 (10)	−0.001 (3)	0.001 (5)	−0.0004 (7)
C4	0.0179 (10)	0.0152 (9)	0.0206 (11)	0.006 (3)	−0.003 (4)	−0.0020 (8)
C5	0.0248 (13)	0.0236 (11)	0.0194 (11)	−0.010 (3)	−0.003 (4)	−0.0061 (9)
C6	0.053 (3)	0.0289 (12)	0.0158 (12)	0.003 (4)	−0.001 (4)	−0.0010 (9)
C7	0.0250 (11)	0.0174 (9)	0.0292 (13)	0.005 (4)	0.001 (6)	−0.0065 (9)
C8	0.0222 (11)	0.0130 (9)	0.0480 (17)	0.000 (4)	−0.001 (6)	−0.0015 (10)
C9	0.0183 (11)	0.0205 (10)	0.0377 (15)	−0.008 (3)	−0.003 (5)	0.0089 (10)
C10	0.0188 (10)	0.0226 (10)	0.0240 (12)	0.002 (4)	−0.001 (5)	0.0059 (9)
I1	0.0493 (1)	0.0319 (1)	0.0177 (1)	−0.0001 (3)	−0.0001 (4)	−0.0009 (1)

Geometric parameters (Å, º)

O1—C1	1.357 (11)	C9—C10	1.389 (4)
O1—H1	0.8200	C1—H1A	0.9700
N1—C4	1.387 (3)	C1—H1B	0.9700
N1—C6	1.471 (4)	C5—H5A	0.9600
N1—C2	1.342 (3)	C5—H5B	0.9600
N2—C3	1.383 (3)	C5—H5C	0.9600
N2—C5	1.469 (3)	C6—H6A	0.9600
N2—C2	1.341 (3)	C6—H6B	0.9600
C1—C2	1.503 (4)	C6—H6C	0.9600
C3—C10	1.397 (3)	C7—H7	0.9300
C3—C4	1.390 (3)	C8—H8	0.9300
C4—C7	1.393 (3)	C9—H9	0.9300
C7—C8	1.383 (4)	C10—H10	0.9300
C8—C9	1.397 (5)
C1—O1—H1	109.00	C2—C1—H1A	109.00
C2—N1—C4	108.6 (2)	C2—C1—H1B	109.00
C2—N1—C6	127.0 (2)	H1A—C1—H1B	108.00
C4—N1—C6	124.1 (2)	N2—C5—H5A	109.00
C2—N2—C3	108.69 (19)	N2—C5—H5B	109.00
C2—N2—C5	125.4 (2)	N2—C5—H5C	109.00
C3—N2—C5	125.9 (2)	H5A—C5—H5B	109.00
O1—C1—C2	111.8 (8)	H5A—C5—H5C	109.00
N1—C2—C1	127.3 (2)	H5B—C5—H5C	109.00
N2—C2—C1	123.5 (2)	N1—C6—H6A	109.00
N1—C2—N2	109.24 (19)	N1—C6—H6B	109.00
N2—C3—C10	131.6 (2)	N1—C6—H6C	109.00
C4—C3—C10	121.5 (2)	H6A—C6—H6B	109.00
N2—C3—C4	106.82 (19)	H6A—C6—H6C	110.00
N1—C4—C7	131.3 (2)	H6B—C6—H6C	109.00
C3—C4—C7	122.1 (2)	C4—C7—H7	122.00
N1—C4—C3	106.66 (19)	C8—C7—H7	122.00
C4—C7—C8	116.5 (3)	C7—C8—H8	119.00
C7—C8—C9	121.6 (2)	C9—C8—H8	119.00
C8—C9—C10	122.1 (3)	C8—C9—H9	119.00
C3—C10—C9	116.2 (2)	C10—C9—H9	119.00
O1—C1—H1A	109.00	C3—C10—H10	122.00
O1—C1—H1B	109.00	C9—C10—H10	122.00
C2—N1—C4—C7	179.2 (12)	C3—N2—C2—C1	176.7 (11)
C6—N1—C4—C7	4.8 (19)	O1—C1—C2—N2	66.5 (13)
C4—N1—C2—N2	1.8 (13)	O1—C1—C2—N1	−115.6 (11)
C6—N1—C2—N2	175.9 (10)	N2—C3—C10—C9	−179.9 (11)
C4—N1—C2—C1	−176.4 (11)	C4—C3—C10—C9	−1.4 (15)
C6—N1—C2—C1	−2 (2)	C10—C3—C4—C7	1.1 (17)
C6—N1—C4—C3	−175.6 (10)	N2—C3—C4—N1	0.3 (12)
C2—N1—C4—C3	−1.2 (12)	N2—C3—C4—C7	179.9 (10)
C5—N2—C2—N1	178.8 (9)	C10—C3—C4—N1	−178.6 (10)
C5—N2—C2—C1	−3.0 (17)	N1—C4—C7—C8	179.2 (11)
C3—N2—C2—N1	−1.6 (13)	C3—C4—C7—C8	−0.4 (17)
C5—N2—C3—C4	−179.6 (9)	C4—C7—C8—C9	0.0 (18)
C2—N2—C3—C10	179.5 (12)	C7—C8—C9—C10	−0.4 (18)
C2—N2—C3—C4	0.8 (12)	C8—C9—C10—C3	1.1 (15)
C5—N2—C3—C10	−0.9 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···I1^i	0.8200	2.6600	3.473 (3)	171.00
C5—H5A···O1	0.9600	2.5200	3.170 (5)	125.00

Symmetry code: (i) x+1, y, z.