metal-organic compounds
3,3-Dimethyl-1,1-(propane-1,3-diyl)diimidazol-1-ium tetrabromidocadmate(II)
aDepartment of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China, and bDepartment of Light Chemical Engineering, College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 210009, People's Republic of China
*Correspondence e-mail: kingwell2004@sina.com.cn
The title compound, (C11H18N4)[CdBr4], was prepared by an The dihedral angle between the two planar imidazolium rings in the cation is 74.4 (4)°. The crystal packing is stabilized by weak intermolecular C—H⋯Br hydrogen bonds between the cation and the tetrahedral anion, building up a three-dimensionnal network.
Related literature
For the properties and applications of ionic liquids, see: Welton (1999); Nicholas et al. (2004); Yu et al. (2007). For dicationic ionic liquids, see: Jared et al. (2005); Liang et al. (2008); Song et al. (2009); Geng et al. (2010). For related structures, see: Jared et al. (2005); Liang et al. (2008). For bond-length data, see: Allen et al. (1987).
Experimental
Crystal data
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Refinement
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Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536810031211/dn2593sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810031211/dn2593Isup2.hkl
A solution of 1,3-dibromide propane(10.1 g, 0.05 mol) in methanol(30 ml) was slowly added to a solution of 1-methylimidazole(9.4 g, 0.11 mol) in methanol(30 ml) at room temperature. The reaction mixture was then refluxed for 6 h. After evaporation of the solvent, the residue was washed with diethyl ether and dichloromethane, then dried in vacuum to obtain ionic liquid 3,3-dimethyl-1,1-(propane-1,3-diyl)- diimidazol-1-ium dibromide (a white solid ionic liquid).
A solution of above mentioned dibromide ionic liquid (3.66 g, 0.01 mol) in methanol(20 ml) was slowly added to a methanol solution of cadmium dibromide (3.44 g, 0.02 mol). The reaction mixture was stirred at room temperature for 3 h. After evaporation of the solvent, the residue was washed with methanol, then dried in vacuum to obtain title compound (I), 3,3-dimethyl-1,1-(propane-1,3-diyl)- diimidazol-1-ium tetrabromide cadmium(II)(yield 84%). M.p. 452–454 K.
Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of methanol. 1H NMR (DMSO, δ, p.p.m.) 8.82 (s, 2 H), 7.49 (d, 4 H), 4.37 (t, 4 H), 3.93 (s,6 H), 2.57 (t, 4 H).
All H atoms attached to C atoms fixed geometrically and treated as riding with C—H = 0.96 Å (methyl), 0.97 Å (methylene) or 0.93 Å (aromatic) with Uiso(H) = 1.2Ueq(C) or Uiso(H) = 1.5Ueq(Cmethyl).
Ionic liquids (ILs) are generally formed by an organic cation and a weakly coordinating anion. They have enjoyed considerable research interests in recent years because of their unique properties such as high thermal stability, non-volatility, non-flammability, high
wide electrochemical window and miscibility with organic compounds (Welton, 1999; Nicholas et al., 2004; Yu et al., 2007). Geminal dicationic ionic liquids have been shown to possess superior physical properties in terms of thermal stability and volatility compared to traditional ionic liquids (ILs) (Jared et al., 2005; Liang et al., 2008; Song et al., 2009). As part of our ongoing studies on new Geminal dicationic ionic liquids (Geng et al., 2010), we report here the of the title compound (I).In (I) (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987). The two imidazolium rings are of course planar but make a dihedral angle of 74.4 (4)° which is much larger than the values reported for related compound as C11H18N4.Br2, 21.5° (Jared et al., 2005) or C11H18N4.2PF6 ,6.1 (2)°(Liang et al., 2008). The dication of the title structure has a highly twisted conformation with the two imidazolium rings almost perpendicular to the C3 plane (angles of C5C6C7-N2C4N1C2C3 and C5C6C7-C8C9N4C10N3 are 79.4 (8)° and 86.1 (6)°, respectively), which are significantly lower than those observed in C11H18N4.Br2 (106.8 (7)° and 92.6 (6)°, respectively) (Jared et al., 2005).
Weak intermolecular C—H···Br hydrogen bonds between tetrabromide cadmium anions and imidazolium cations build up a three dimensionnal network. (Table 1, Fig.2).
For the properties and applications of ionic liquids, see: Welton (1999); Nicholas et al. (2004); Yu et al. (2007). For dicationic ionic liquids, see: Jared et al. (2005); Liang et al. (2008); Song et al. (2009); Geng et al. (2010). For related structures, see: Jared et al. (2005); Liang et al. (2008). For bond-length data, see: Allen et al. (1987).
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell
CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).(C11H18N4)[CdBr4] | F(000) = 1200 |
Mr = 638.33 | Dx = 2.282 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 25 reflections |
a = 8.5050 (17) Å | θ = 9–13° |
b = 15.876 (3) Å | µ = 9.78 mm−1 |
c = 13.836 (3) Å | T = 293 K |
β = 96.07 (3)° | Block, white |
V = 1857.7 (6) Å3 | 0.20 × 0.10 × 0.10 mm |
Z = 4 |
Enraf–Nonius CAD-4 diffractometer | 1874 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 25.3°, θmin = 2.0° |
ω/2θ scans | h = −10→10 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→19 |
Tmin = 0.245, Tmax = 0.442 | l = 0→16 |
3383 measured reflections | 3 standard reflections every 200 reflections |
3383 independent reflections | intensity decay: 1% |
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)] = 0.062 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.144 | H-atom parameters constrained |
S = 0.95 | w = 1/[σ2(Fo2) + (0.066P)2] where P = (Fo2 + 2Fc2)/3 |
3383 reflections | (Δ/σ)max < 0.001 |
183 parameters | Δρmax = 0.72 e Å−3 |
0 restraints | Δρmin = −0.77 e Å−3 |
(C11H18N4)[CdBr4] | V = 1857.7 (6) Å3 |
Mr = 638.33 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.5050 (17) Å | µ = 9.78 mm−1 |
b = 15.876 (3) Å | T = 293 K |
c = 13.836 (3) Å | 0.20 × 0.10 × 0.10 mm |
β = 96.07 (3)° |
Enraf–Nonius CAD-4 diffractometer | 1874 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.000 |
Tmin = 0.245, Tmax = 0.442 | 3 standard reflections every 200 reflections |
3383 measured reflections | intensity decay: 1% |
3383 independent reflections |
R[F2 > 2σ(F2)] = 0.062 | 0 restraints |
wR(F2) = 0.144 | H-atom parameters constrained |
S = 0.95 | Δρmax = 0.72 e Å−3 |
3383 reflections | Δρmin = −0.77 e Å−3 |
183 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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. |
x | y | z | Uiso*/Ueq | ||
N1 | 0.2634 (10) | 0.0761 (6) | 0.4518 (6) | 0.045 (2) | |
N2 | 0.2576 (10) | 0.2095 (6) | 0.4221 (7) | 0.052 (2) | |
N3 | 0.5789 (10) | 0.3667 (6) | 0.6079 (7) | 0.060 (3) | |
N4 | 0.8099 (10) | 0.3936 (6) | 0.6694 (6) | 0.047 (2) | |
C1 | 0.2360 (16) | −0.0015 (9) | 0.4950 (10) | 0.095 (5) | |
H1A | 0.2116 | 0.0075 | 0.5604 | 0.142* | |
H1B | 0.3289 | −0.0360 | 0.4959 | 0.142* | |
H1C | 0.1488 | −0.0293 | 0.4584 | 0.142* | |
C2 | 0.3518 (14) | 0.0926 (9) | 0.3730 (9) | 0.066 (4) | |
H2A | 0.4038 | 0.0519 | 0.3400 | 0.079* | |
C3 | 0.3505 (13) | 0.1739 (8) | 0.3527 (9) | 0.064 (4) | |
H3A | 0.3989 | 0.2014 | 0.3045 | 0.076* | |
C4 | 0.2128 (11) | 0.1516 (8) | 0.4794 (8) | 0.050 (3) | |
H4A | 0.1545 | 0.1609 | 0.5315 | 0.060* | |
C5 | 0.2341 (14) | 0.3012 (8) | 0.4287 (9) | 0.068 (4) | |
H5A | 0.1515 | 0.3121 | 0.4704 | 0.081* | |
H5B | 0.1983 | 0.3228 | 0.3646 | 0.081* | |
C6 | 0.3818 (15) | 0.3485 (8) | 0.4682 (9) | 0.074 (4) | |
H6A | 0.4681 | 0.3349 | 0.4304 | 0.089* | |
H6B | 0.3630 | 0.4087 | 0.4637 | 0.089* | |
C7 | 0.4240 (18) | 0.3240 (9) | 0.5717 (11) | 0.096 (5) | |
H7A | 0.4352 | 0.2634 | 0.5770 | 0.115* | |
H7B | 0.3414 | 0.3416 | 0.6106 | 0.115* | |
C8 | 0.5739 (14) | 0.4410 (8) | 0.6537 (8) | 0.057 (3) | |
H8A | 0.4833 | 0.4729 | 0.6583 | 0.068* | |
C9 | 0.7154 (16) | 0.4612 (8) | 0.6906 (9) | 0.067 (4) | |
H9A | 0.7468 | 0.5103 | 0.7240 | 0.080* | |
C10 | 0.7192 (13) | 0.3354 (8) | 0.6172 (8) | 0.055 (3) | |
H10A | 0.7515 | 0.2842 | 0.5934 | 0.065* | |
C11 | 0.9894 (14) | 0.3870 (10) | 0.7007 (12) | 0.107 (6) | |
H11A | 1.0261 | 0.4384 | 0.7320 | 0.160* | |
H11B | 1.0442 | 0.3778 | 0.6444 | 0.160* | |
H11C | 1.0094 | 0.3408 | 0.7450 | 0.160* | |
Cd1 | 0.77770 (8) | 0.15445 (5) | 0.80145 (6) | 0.0423 (2) | |
Br1 | 0.79089 (15) | 0.29343 (8) | 0.89683 (10) | 0.0652 (4) | |
Br2 | 0.50899 (14) | 0.13451 (8) | 0.69780 (10) | 0.0643 (4) | |
Br3 | 1.00029 (15) | 0.14239 (11) | 0.69122 (10) | 0.0832 (5) | |
Br4 | 0.8109 (2) | 0.04053 (11) | 0.92709 (13) | 0.1013 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.048 (6) | 0.046 (6) | 0.043 (5) | −0.003 (5) | 0.011 (4) | −0.003 (4) |
N2 | 0.040 (6) | 0.056 (6) | 0.061 (6) | 0.011 (5) | 0.004 (5) | −0.009 (5) |
N3 | 0.046 (6) | 0.034 (6) | 0.092 (8) | −0.013 (4) | −0.031 (5) | 0.002 (5) |
N4 | 0.044 (5) | 0.057 (6) | 0.042 (5) | −0.002 (5) | 0.010 (4) | 0.021 (5) |
C1 | 0.097 (11) | 0.091 (11) | 0.094 (11) | −0.056 (9) | 0.004 (9) | 0.006 (10) |
C2 | 0.062 (9) | 0.070 (9) | 0.070 (9) | −0.008 (7) | 0.029 (7) | −0.016 (7) |
C3 | 0.054 (8) | 0.077 (10) | 0.063 (8) | −0.019 (7) | 0.020 (6) | −0.018 (7) |
C4 | 0.031 (6) | 0.081 (9) | 0.037 (6) | 0.006 (6) | 0.005 (5) | −0.009 (7) |
C5 | 0.064 (9) | 0.077 (10) | 0.055 (8) | −0.001 (7) | −0.027 (6) | 0.004 (7) |
C6 | 0.094 (10) | 0.073 (9) | 0.056 (8) | 0.005 (8) | 0.009 (7) | 0.000 (8) |
C7 | 0.122 (14) | 0.065 (10) | 0.099 (12) | −0.021 (9) | 0.005 (10) | −0.013 (8) |
C8 | 0.054 (8) | 0.062 (9) | 0.052 (7) | 0.002 (6) | −0.001 (6) | −0.003 (6) |
C9 | 0.103 (11) | 0.043 (7) | 0.052 (7) | 0.010 (8) | 0.004 (7) | −0.009 (6) |
C10 | 0.045 (7) | 0.061 (8) | 0.057 (7) | −0.006 (6) | 0.001 (6) | 0.015 (6) |
C11 | 0.053 (9) | 0.080 (11) | 0.183 (18) | −0.017 (8) | −0.009 (10) | 0.034 (11) |
Cd1 | 0.0313 (4) | 0.0491 (5) | 0.0475 (5) | −0.0006 (4) | 0.0080 (3) | −0.0051 (4) |
Br1 | 0.0724 (9) | 0.0536 (8) | 0.0706 (9) | −0.0055 (6) | 0.0119 (7) | −0.0081 (6) |
Br2 | 0.0457 (7) | 0.0684 (9) | 0.0760 (9) | −0.0047 (6) | −0.0061 (6) | −0.0025 (7) |
Br3 | 0.0583 (8) | 0.1260 (14) | 0.0684 (9) | 0.0112 (9) | 0.0214 (7) | −0.0020 (9) |
Br4 | 0.1088 (13) | 0.0956 (12) | 0.1011 (12) | 0.0178 (10) | 0.0180 (10) | 0.0049 (10) |
N1—C4 | 1.342 (13) | C5—C6 | 1.514 (16) |
N1—C1 | 1.400 (15) | C5—H5A | 0.9700 |
N1—C2 | 1.412 (13) | C5—H5B | 0.9700 |
N2—C4 | 1.297 (13) | C6—C7 | 1.490 (17) |
N2—C3 | 1.423 (14) | C6—H6A | 0.9700 |
N2—C5 | 1.475 (15) | C6—H6B | 0.9700 |
N3—C10 | 1.286 (13) | C7—H7A | 0.9700 |
N3—C8 | 1.341 (14) | C7—H7B | 0.9700 |
N3—C7 | 1.519 (15) | C8—C9 | 1.297 (15) |
N4—C10 | 1.362 (13) | C8—H8A | 0.9300 |
N4—C9 | 1.391 (13) | C9—H9A | 0.9300 |
N4—C11 | 1.545 (14) | C10—H10A | 0.9300 |
C1—H1A | 0.9600 | C11—H11A | 0.9600 |
C1—H1B | 0.9600 | C11—H11B | 0.9600 |
C1—H1C | 0.9600 | C11—H11C | 0.9600 |
C2—C3 | 1.321 (17) | Cd1—Br4 | 2.5036 (19) |
C2—H2A | 0.9300 | Cd1—Br3 | 2.5608 (16) |
C3—H3A | 0.9300 | Cd1—Br1 | 2.5673 (15) |
C4—H4A | 0.9300 | Cd1—Br2 | 2.5858 (16) |
C4—N1—C1 | 126.2 (10) | C7—C6—C5 | 108.9 (11) |
C4—N1—C2 | 105.5 (9) | C7—C6—H6A | 109.9 |
C1—N1—C2 | 128.3 (11) | C5—C6—H6A | 109.9 |
C4—N2—C3 | 110.5 (10) | C7—C6—H6B | 109.9 |
C4—N2—C5 | 127.7 (11) | C5—C6—H6B | 109.9 |
C3—N2—C5 | 121.5 (11) | H6A—C6—H6B | 108.3 |
C10—N3—C8 | 111.6 (9) | C6—C7—N3 | 108.2 (11) |
C10—N3—C7 | 128.6 (11) | C6—C7—H7A | 110.0 |
C8—N3—C7 | 118.6 (11) | N3—C7—H7A | 110.0 |
C10—N4—C9 | 109.1 (10) | C6—C7—H7B | 110.0 |
C10—N4—C11 | 126.2 (11) | N3—C7—H7B | 110.0 |
C9—N4—C11 | 124.7 (12) | H7A—C7—H7B | 108.4 |
N1—C1—H1A | 109.5 | C9—C8—N3 | 109.2 (11) |
N1—C1—H1B | 109.5 | C9—C8—H8A | 125.4 |
H1A—C1—H1B | 109.5 | N3—C8—H8A | 125.4 |
N1—C1—H1C | 109.5 | C8—C9—N4 | 105.0 (11) |
H1A—C1—H1C | 109.5 | C8—C9—H9A | 127.5 |
H1B—C1—H1C | 109.5 | N4—C9—H9A | 127.5 |
C3—C2—N1 | 110.6 (11) | N3—C10—N4 | 105.0 (10) |
C3—C2—H2A | 124.7 | N3—C10—H10A | 127.5 |
N1—C2—H2A | 124.7 | N4—C10—H10A | 127.5 |
C2—C3—N2 | 103.7 (11) | N4—C11—H11A | 109.5 |
C2—C3—H3A | 128.1 | N4—C11—H11B | 109.5 |
N2—C3—H3A | 128.1 | H11A—C11—H11B | 109.5 |
N2—C4—N1 | 109.6 (9) | N4—C11—H11C | 109.5 |
N2—C4—H4A | 125.2 | H11A—C11—H11C | 109.5 |
N1—C4—H4A | 125.2 | H11B—C11—H11C | 109.5 |
N2—C5—C6 | 113.6 (10) | Br4—Cd1—Br3 | 108.87 (6) |
N2—C5—H5A | 108.9 | Br4—Cd1—Br1 | 105.57 (6) |
C6—C5—H5A | 108.9 | Br3—Cd1—Br1 | 112.06 (6) |
N2—C5—H5B | 108.9 | Br4—Cd1—Br2 | 108.95 (6) |
C6—C5—H5B | 108.9 | Br3—Cd1—Br2 | 109.04 (6) |
H5A—C5—H5B | 107.7 | Br1—Cd1—Br2 | 112.23 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7A···Br2 | 0.97 | 2.67 | 3.515 (15) | 145 |
C1—H1C···Br3i | 0.96 | 2.93 | 3.819 (13) | 155 |
C4—H4A···Br3ii | 0.93 | 2.70 | 3.606 (11) | 164 |
C5—H5B···Br3iii | 0.97 | 2.84 | 3.765 (11) | 161 |
C8—H8A···Br4iv | 0.93 | 2.86 | 3.699 (12) | 151 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x−1, y, z; (iii) x−1, −y+1/2, z−1/2; (iv) −x+1, y+1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | (C11H18N4)[CdBr4] |
Mr | 638.33 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 8.5050 (17), 15.876 (3), 13.836 (3) |
β (°) | 96.07 (3) |
V (Å3) | 1857.7 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 9.78 |
Crystal size (mm) | 0.20 × 0.10 × 0.10 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.245, 0.442 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3383, 3383, 1874 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.601 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.062, 0.144, 0.95 |
No. of reflections | 3383 |
No. of parameters | 183 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.72, −0.77 |
Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7A···Br2 | 0.97 | 2.67 | 3.515 (15) | 145.2 |
C1—H1C···Br3i | 0.96 | 2.93 | 3.819 (13) | 155.2 |
C4—H4A···Br3ii | 0.93 | 2.70 | 3.606 (11) | 164.2 |
C5—H5B···Br3iii | 0.97 | 2.84 | 3.765 (11) | 160.7 |
C8—H8A···Br4iv | 0.93 | 2.86 | 3.699 (12) | 150.6 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x−1, y, z; (iii) x−1, −y+1/2, z−1/2; (iv) −x+1, y+1/2, −z+3/2. |
Acknowledgements
This work was supported by the Foundation for Young Teachers Scholarship of Nanjing University of Technology, Jiangsu, China (grant No. 39729005). The authors also thank the Centre of Testing and Analysis, Nanjing University, for the data collection.
References
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Ionic liquids (ILs) are generally formed by an organic cation and a weakly coordinating anion. They have enjoyed considerable research interests in recent years because of their unique properties such as high thermal stability, non-volatility, non-flammability, high ionic conductivity, wide electrochemical window and miscibility with organic compounds (Welton, 1999; Nicholas et al., 2004; Yu et al., 2007). Geminal dicationic ionic liquids have been shown to possess superior physical properties in terms of thermal stability and volatility compared to traditional ionic liquids (ILs) (Jared et al., 2005; Liang et al., 2008; Song et al., 2009). As part of our ongoing studies on new Geminal dicationic ionic liquids (Geng et al., 2010), we report here the crystal structure of the title compound (I).
In (I) (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987). The two imidazolium rings are of course planar but make a dihedral angle of 74.4 (4)° which is much larger than the values reported for related compound as C11H18N4.Br2, 21.5° (Jared et al., 2005) or C11H18N4.2PF6 ,6.1 (2)°(Liang et al., 2008). The dication of the title structure has a highly twisted conformation with the two imidazolium rings almost perpendicular to the C3 plane (angles of C5C6C7-N2C4N1C2C3 and C5C6C7-C8C9N4C10N3 are 79.4 (8)° and 86.1 (6)°, respectively), which are significantly lower than those observed in C11H18N4.Br2 (106.8 (7)° and 92.6 (6)°, respectively) (Jared et al., 2005).
Weak intermolecular C—H···Br hydrogen bonds between tetrabromide cadmium anions and imidazolium cations build up a three dimensionnal network. (Table 1, Fig.2).