3,3′-Dimethyl-1,1′-methyl­ene­diimidazolium dibromide

Liu, J.; Wei, X.; Wei, Z.; Liu, J.; Zheng, L.

doi:10.1107/S1600536809028967

organic compounds

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ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page o2027

doi:10.1107/S1600536809028967

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3,3′-Dimethyl-1,1′-methylenediimidazolium dibromide

Jie Liu,^a,^b Xilian Wei,^b Zengbin Wei,^b Jiuqiang Liu ^b and Liqiang Zheng ^a ^*

^aKey Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan 250100, People's Republic of China, and ^bCollege of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, People's Republic of China
^*Correspondence e-mail: lqzheng@sdu.edu.cn

(Received 4 July 2009; accepted 22 July 2009; online 29 July 2009)

In the crystal structure of the title compound, C₉H₁₄N₄²⁺·2Br⁻, the cation and anions have crystallographic mirror symmetry, with the mirror plane running through the central CH₂ group for the cation. The latter are stacked along the a axis, forming channels hosting the bromide anions. The crystal packing is stabilized by C—H⋯Br hydrogen-bonding interactions, generating a two-dimensional network.

Related literature

For related structures, see: Jin et al. (2007 ); Eicher et al. (2003 ).

Experimental

Crystal data

C₉H₁₄N₄²⁺·2Br⁻
M_r = 338.06
Monoclinic, P 2₁ /m
a = 4.7310 (5) Å
b = 11.3861 (12) Å
c = 11.8419 (15) Å
β = 93.672 (1)°
V = 636.59 (12) Å³
Z = 2
Mo Kα radiation
μ = 6.34 mm⁻¹
T = 298 K
0.32 × 0.10 × 0.07 mm

Data collection

Bruker SMART diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.227, T_max = 0.638
3349 measured reflections
1188 independent reflections
928 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.028
wR(F²) = 0.066
S = 1.07
1188 reflections
74 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯Br1ⁱ	0.93	2.84	3.724 (3)	158
C3—H3⋯Br1ⁱⁱ	0.93	2.81	3.699 (3)	160
C1—H1A⋯Br1ⁱⁱⁱ	0.97	2.76	3.723 (4)	172
C2—H2⋯Br2^iv	0.93	2.82	3.627 (3)	146
C1—H1B⋯Br2^iv	0.97	2.81	3.652 (5)	146
Symmetry codes: (i) -x+1, -y+1, -z; (ii) x+1, y, z; (iii) -x, -y+1, -z; (iv) x-1, y, z.

Data collection: SMART (Siemens, 1996 ); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809028967/rz2350sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809028967/rz2350Isup2.hkl

checkCIF report

Comment top

The title compound was synthesized as the precursor of a chelating N-heterocyclic carbene ligand, which can be generated by deprotonating the ring between the two N atoms of the two imidazolium cations.(Jin et al., 2007).

The structure consists of dimethylethylenediimidazolium cations and bromide anions (Fig. 1). The cation has crystallographically imposed mirror symmetry, with atom C1 located on a mirror plane. Both independent bromide anions also lie on a mirror plane. The C1—N1 bond length is 1.455 (4) Å, and the N1—C1—N1 bond angle is 111.0 (4)°. The C2—N1—C4 bond angle of 108.4 (3)° is similar to those observed in free imidazole (Eicher et al., 2003). The relative orientation of the imidazolium ring with respect to the other imidazolium ring can be described by the value of -95.4 (4)° of the C2—N1—C1—N1 torsion angle. In the crystal, the cations are stacked along the a axis forming channels that are occupied by the bromide anions (Fig. 2). Adjacent molecules are connected into a two-dimensional network through C—H···Br hydrogen interactions (Table 1).

Related literature top

For related structures, see: Jin et al. (2007); Eicher et al. (2003).

Experimental top

A mixture of 1-methylimidazole (0.1 mol) and dichloromethane (0.05 mol) was reacted under nitrogen atmosphere with stirring at 350 K for 48 h. The resulting clear solution was evaporated under vacuum. Colourless crystals suitable for X-ray analysis were obtained by slow evaporation of a ethyl acetate solution over a period of two weeks. (yield 83%) Anal. Calcd (%) for C₉H₁₄Br₂N₄ (Mr = 338.06): C, 32.03; H, 4.09; N, 16.62. Found (%): C, 31.95; H, 4.14; N, 16.57.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the compound, with atom labels and 50% probability displacement ellipsoids. Unlabelled atoms are related to labelled atoms by (x, 0.5-y, z)
	Fig. 2. Crystal packing of the compound, showing the two-dimensional network structure formed by C—H···Br hydrogen bonds (dashed lines).

3,3'-Dimethyl-1,1'-methylenediimidazolium dibromide top

Crystal data top

C₉H₁₄N₄²⁺·2Br⁻	F(000) = 332
M_r = 338.06	D_x = 1.764 Mg m⁻³
Monoclinic, P2₁/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yb	Cell parameters from 1657 reflections
a = 4.7310 (5) Å	θ = 2.5–26.3°
b = 11.3861 (12) Å	µ = 6.34 mm⁻¹
c = 11.8419 (15) Å	T = 298 K
β = 93.672 (1)°	Block, colourless
V = 636.59 (12) Å³	0.32 × 0.10 × 0.07 mm
Z = 2

Data collection top

Bruker SMART diffractometer	1188 independent reflections
Radiation source: fine-focus sealed tube	928 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
ϕ and ω scans	θ_max = 25.0°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→5
T_min = 0.227, T_max = 0.638	k = −13→10
3349 measured reflections	l = −14→13

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.066	H-atom parameters constrained
S = 1.07	w = 1/[σ²(F_o²) + (0.0319P)²] where P = (F_o² + 2F_c²)/3
1188 reflections	(Δ/σ)_max < 0.001
74 parameters	Δρ_max = 0.63 e Å⁻³
0 restraints	Δρ_min = −0.27 e Å⁻³

Crystal data top

C₉H₁₄N₄²⁺·2Br⁻	V = 636.59 (12) Å³
M_r = 338.06	Z = 2
Monoclinic, P2₁/m	Mo Kα radiation
a = 4.7310 (5) Å	µ = 6.34 mm⁻¹
b = 11.3861 (12) Å	T = 298 K
c = 11.8419 (15) Å	0.32 × 0.10 × 0.07 mm
β = 93.672 (1)°

Data collection top

Bruker SMART diffractometer	1188 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	928 reflections with I > 2σ(I)
T_min = 0.227, T_max = 0.638	R_int = 0.031
3349 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.028	0 restraints
wR(F²) = 0.066	H-atom parameters constrained
S = 1.07	Δρ_max = 0.63 e Å⁻³
1188 reflections	Δρ_min = −0.27 e Å⁻³
74 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.14906 (11)	0.7500	0.12842 (4)	0.04708 (18)
Br2	0.86811 (10)	0.2500	0.43062 (4)	0.04621 (18)
N1	0.3731 (5)	0.3553 (2)	0.18410 (19)	0.0333 (6)
N2	0.5612 (5)	0.5023 (2)	0.2736 (2)	0.0375 (6)
C1	0.2048 (10)	0.2500	0.1615 (4)	0.0410 (11)
H1A	0.1319	0.2500	0.0831	0.049*
H1B	0.0447	0.2500	0.2088	0.049*
C2	0.3825 (7)	0.4151 (3)	0.2809 (2)	0.0361 (8)
H2	0.2796	0.3978	0.3431	0.043*
C3	0.6745 (7)	0.4977 (3)	0.1702 (3)	0.0450 (8)
H3	0.8081	0.5490	0.1436	0.054*
C4	0.5580 (7)	0.4061 (3)	0.1145 (3)	0.0421 (8)
H4	0.5953	0.3814	0.0421	0.050*
C5	0.6396 (9)	0.5872 (3)	0.3625 (3)	0.0699 (13)
H5A	0.4742	0.6296	0.3820	0.105*
H5B	0.7764	0.6412	0.3360	0.105*
H5C	0.7197	0.5466	0.4280	0.105*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0526 (4)	0.0461 (3)	0.0433 (3)	0.000	0.0087 (2)	0.000
Br2	0.0433 (3)	0.0484 (3)	0.0471 (3)	0.000	0.0040 (2)	0.000
N1	0.0389 (16)	0.0264 (14)	0.0339 (14)	0.0034 (12)	−0.0035 (12)	0.0049 (12)
N2	0.0483 (17)	0.0230 (14)	0.0405 (15)	−0.0001 (14)	−0.0022 (13)	−0.0011 (12)
C1	0.041 (3)	0.037 (3)	0.043 (3)	0.000	−0.008 (2)	0.000
C2	0.043 (2)	0.0321 (18)	0.0327 (16)	0.0052 (16)	0.0014 (14)	−0.0011 (14)
C3	0.053 (2)	0.0311 (18)	0.051 (2)	−0.0003 (17)	0.0103 (17)	0.0093 (17)
C4	0.055 (2)	0.0358 (18)	0.0355 (17)	0.0082 (17)	0.0063 (16)	0.0059 (16)
C5	0.109 (4)	0.042 (2)	0.058 (3)	−0.019 (2)	0.003 (2)	−0.0142 (19)

Geometric parameters (Å, º) top

N1—C2	1.331 (3)	C1—H1B	0.9700
N1—C4	1.368 (4)	C2—H2	0.9300
N1—C1	1.455 (4)	C3—C4	1.334 (4)
N2—C2	1.311 (4)	C3—H3	0.9300
N2—C3	1.370 (4)	C4—H4	0.9300
N2—C5	1.459 (4)	C5—H5A	0.9600
C1—N1ⁱ	1.455 (4)	C5—H5B	0.9600
C1—H1A	0.9700	C5—H5C	0.9600

C2—N1—C4	108.4 (3)	N1—C2—H2	125.8
C2—N1—C1	124.6 (3)	C4—C3—N2	107.4 (3)
C4—N1—C1	127.0 (3)	C4—C3—H3	126.3
C2—N2—C3	108.7 (3)	N2—C3—H3	126.3
C2—N2—C5	126.1 (3)	C3—C4—N1	107.0 (3)
C3—N2—C5	125.1 (3)	C3—C4—H4	126.5
N1—C1—N1ⁱ	111.0 (4)	N1—C4—H4	126.5
N1—C1—H1A	109.4	N2—C5—H5A	109.5
N1ⁱ—C1—H1A	109.4	N2—C5—H5B	109.5
N1—C1—H1B	109.4	H5A—C5—H5B	109.5
N1ⁱ—C1—H1B	109.4	N2—C5—H5C	109.5
H1A—C1—H1B	108.0	H5A—C5—H5C	109.5
N2—C2—N1	108.5 (3)	H5B—C5—H5C	109.5
N2—C2—H2	125.8

C2—N1—C1—N1ⁱ	−95.4 (4)	C2—N2—C3—C4	0.6 (4)
C4—N1—C1—N1ⁱ	80.7 (4)	C5—N2—C3—C4	177.6 (3)
C3—N2—C2—N1	−1.1 (3)	N2—C3—C4—N1	0.2 (4)
C5—N2—C2—N1	−178.2 (3)	C2—N1—C4—C3	−0.9 (4)
C4—N1—C2—N2	1.2 (3)	C1—N1—C4—C3	−177.5 (3)
C1—N1—C2—N2	177.9 (3)

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···Br1ⁱⁱ	0.93	2.84	3.724 (3)	158
C3—H3···Br1ⁱⁱⁱ	0.93	2.81	3.699 (3)	160
C1—H1A···Br1^iv	0.97	2.76	3.723 (4)	172
C2—H2···Br2^v	0.93	2.82	3.627 (3)	146
C1—H1B···Br2^v	0.97	2.81	3.652 (5)	146

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

Experimental details

Crystal data
Chemical formula	C₉H₁₄N₄²⁺·2Br⁻
M_r	338.06
Crystal system, space group	Monoclinic, P2₁/m
Temperature (K)	298
a, b, c (Å)	4.7310 (5), 11.3861 (12), 11.8419 (15)
β (°)	93.672 (1)
V (Å³)	636.59 (12)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	6.34
Crystal size (mm)	0.32 × 0.10 × 0.07

Data collection
Diffractometer	Bruker SMART diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.227, 0.638
No. of measured, independent and observed [I > 2σ(I)] reflections	3349, 1188, 928
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.028, 0.066, 1.07
No. of reflections	1188
No. of parameters	74
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.63, −0.27

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···Br1ⁱ	0.93	2.84	3.724 (3)	158.1
C3—H3···Br1ⁱⁱ	0.93	2.81	3.699 (3)	159.6
C1—H1A···Br1ⁱⁱⁱ	0.97	2.76	3.723 (4)	172.0
C2—H2···Br2^iv	0.93	2.82	3.627 (3)	145.7
C1—H1B···Br2^iv	0.97	2.81	3.652 (5)	146.1

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

Acknowledgements

We acknowledge financial support by the National Natural Science Foundation of China (20773081, 20873074) and the National Basic Research Program (2007CB808004, 2009CB30101).

References

Eicher, T., Hauptmann, S. & Speicher, A. (2003). The Chemistry of Heterocycles: Structures, Reactions, Synthesis and Applications, 2th ed. Weinheim: Wiley-VCH. Google Scholar
Jin, H.-S., Wang, H.-J., Zhang, Y., Zuo, Y.-J. & Zhong, C.-M. (2007). Acta Cryst. E63, o1880–o1881. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar