PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2009 August 1; 65(Pt 8): o1828.
Published online 2009 July 11. doi:  10.1107/S1600536809026324
PMCID: PMC2977381

1,1′,2,2′-Tetra­methyl-3,3′-(p-phenyl­enedimethyl­ene)diimidazol-1-ium dibromide

Abstract

The title imidazolium-based ionic-liquid salt, C18H24N4 2+·2Br, has the cation lying about a center of inversion. The five-membered imidazole ring is disordered over two positions with the major component having a site occupancy of 0.712 (4); the N-bound methyl substituents are ordered. The imidazole ring is approximately perpendicular to the six-membered phenyl­ene ring [dihedral angle = 80.7 (5)° for the major disorder component and 89.8 (3)° for the other; the two components are off-set by 10.1 (6)°].

Related literature

For background to imidazolium-based ionic liquid salts, see: Ganesan et al. (2008 [triangle]). For 2,2′-dimethyl-3,3′-(p-phenyl­enedimethyl­ene)diimidazol-1-ium dibromide, see: Dobrzańska (2005 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-o1828-scheme1.jpg

Experimental

Crystal data

  • C18H24N4 2+·2Br
  • M r = 456.23
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o1828-efi1.jpg
  • a = 8.5689 (4) Å
  • b = 9.8617 (5) Å
  • c = 11.0272 (4) Å
  • β = 93.222 (3)°
  • V = 930.37 (7) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 4.36 mm−1
  • T = 140 K
  • 0.40 × 0.08 × 0.04 mm

Data collection

  • Bruker SMART APEX diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.274, T max = 0.845
  • 5882 measured reflections
  • 2131 independent reflections
  • 1575 reflections with I > 2σ(I)
  • R int = 0.051

Refinement

  • R[F 2 > 2σ(F 2)] = 0.039
  • wR(F 2) = 0.096
  • S = 1.04
  • 2131 reflections
  • 112 parameters
  • 36 restraints
  • H-atom parameters constrained
  • Δρmax = 0.54 e Å−3
  • Δρmin = −0.99 e Å−3

Data collection: APEX2 (Bruker, 2008 [triangle]); cell refinement: SAINT (Bruker, 2008 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: X-SEED (Barbour, 2001 [triangle]); software used to prepare material for publication: publCIF (Westrip, 2009 [triangle]).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809026324/tk2494sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809026324/tk2494Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

We thank the University of Malaya (grant Nos. TA 0009/2008 A and FS343/2008 A) for supporting this study.

supplementary crystallographic information

Experimental

α,α-Dibromo-p-xylene (0.78 g, 3 mmol) and 1,2-dimethylimidazole (0.58 g, 6 mmol) were refluxed in DMF (50 ml) for 3 h. The product that separated from solution was collected and washed with ether. Crystals were grown from its solution in water.

Refinement

The imidazolyl ring is disordered over two positions (the two N-bound methyl groups are ordered); the major component had a site occupancy = 0.712 (4). The ring was refined as a regular pentagon of 1.35 Å sides. The anisotropic displacement parameters of the primed atoms were restrained to those of the unprimed ones; these were further restrained to be nearly isotropic.

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 to 0.99 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2 to 1.5Ueq(C).

Figures

Fig. 1.
Thermal ellipsoid plot (Barbour, 2001) of [C18H24N4]2+ 2Br- at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius. The imidazolyl ring is disordered; the minor component of the disorder is not shown. The non-H atoms comprising ...

Crystal data

C18H24N42+·2BrF(000) = 460
Mr = 456.23Dx = 1.629 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1543 reflections
a = 8.5689 (4) Åθ = 2.8–25.5°
b = 9.8617 (5) ŵ = 4.36 mm1
c = 11.0272 (4) ÅT = 140 K
β = 93.222 (3)°Prism, colorless
V = 930.37 (7) Å30.40 × 0.08 × 0.04 mm
Z = 2

Data collection

Bruker SMART APEX diffractometer2131 independent reflections
Radiation source: fine-focus sealed tube1575 reflections with I > 2σ(I)
graphiteRint = 0.051
ω scansθmax = 27.5°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −11→10
Tmin = 0.274, Tmax = 0.845k = −12→12
5882 measured reflectionsl = −14→14

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.096H-atom parameters constrained
S = 1.04w = 1/[σ2(Fo2) + (0.0403P)2 + 0.5004P] where P = (Fo2 + 2Fc2)/3
2131 reflections(Δ/σ)max = 0.001
112 parametersΔρmax = 0.54 e Å3
36 restraintsΔρmin = −0.99 e Å3

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

xyzUiso*/UeqOcc. (<1)
Br10.46792 (4)0.59691 (4)0.76873 (3)0.02742 (14)
C10.6432 (4)0.0488 (4)0.4669 (3)0.0194 (7)
H10.74140.08230.44450.023*
C20.6148 (4)0.0331 (3)0.5895 (3)0.0194 (7)
H20.69360.05580.65010.023*
C30.4712 (4)−0.0158 (3)0.6230 (3)0.0188 (7)
C40.4343 (4)−0.0353 (4)0.7539 (3)0.0201 (7)
H4A0.3204−0.02460.76150.024*0.712 (4)
H4B0.4631−0.12870.77940.024*0.712 (4)
H4C0.4003−0.13030.76490.024*0.288 (4)
H4D0.34520.02410.77140.024*0.288 (4)
N10.5158 (3)0.0594 (3)0.8328 (3)0.0199 (10)0.712 (4)
C50.4760 (4)0.1910 (3)0.8444 (3)0.0259 (11)0.712 (4)
H50.38620.23360.80720.031*0.712 (4)
C60.5862 (4)0.2513 (2)0.9182 (3)0.0270 (13)0.712 (4)
H60.58750.34390.94210.032*0.712 (4)
N20.6941 (3)0.1570 (3)0.9523 (3)0.0207 (9)0.712 (4)
C70.6507 (4)0.0384 (2)0.8994 (3)0.0203 (11)0.712 (4)
C80.7408 (7)−0.0908 (5)0.9105 (5)0.0256 (12)0.712 (4)
H8A0.8262−0.08890.85490.038*0.712 (4)
H8B0.6714−0.16730.88960.038*0.712 (4)
H8C0.7842−0.10120.99410.038*0.712 (4)
N1'0.5677 (9)−0.0057 (8)0.8456 (6)0.0199 (10)0.288
C5'0.6581 (11)−0.1058 (6)0.8950 (8)0.0259 (11)0.288
H5'0.6480−0.19980.87750.031*0.288 (4)
C6'0.7654 (9)−0.0488 (8)0.9736 (8)0.0270 (13)0.288
H6'0.8440−0.09561.02110.032*0.288 (4)
N2'0.7413 (9)0.0865 (7)0.9728 (7)0.0207 (9)0.288
C7'0.6192 (10)0.1132 (6)0.8937 (7)0.0203 (11)0.288
C8'0.5509 (19)0.2515 (14)0.8644 (14)0.0256 (12)0.288
H8'10.54730.30480.93920.038*0.288 (4)
H8'20.44480.24120.82750.038*0.288 (4)
H8'30.61620.29830.80740.038*0.288 (4)
C90.8342 (5)0.1840 (4)1.0313 (3)0.0293 (9)
H9A0.82780.27551.06540.044*0.712 (4)
H9B0.92720.17700.98400.044*0.712 (4)
H9C0.84100.11751.09750.044*0.712 (4)
H9D0.77980.27151.02790.044*0.288 (4)
H9E0.93300.19190.99120.044*0.288 (4)
H9F0.85550.15771.11640.044*0.288 (4)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br10.0221 (2)0.0266 (2)0.0336 (2)0.00039 (17)0.00258 (14)−0.00512 (16)
C10.0122 (19)0.0253 (17)0.0208 (17)−0.0017 (14)0.0021 (13)0.0009 (13)
C20.016 (2)0.0235 (18)0.0183 (17)0.0002 (14)−0.0025 (13)−0.0002 (13)
C30.019 (2)0.0188 (17)0.0192 (17)0.0022 (14)0.0025 (13)0.0007 (13)
C40.013 (2)0.0275 (18)0.0194 (17)−0.0009 (14)−0.0008 (13)0.0010 (13)
N10.018 (2)0.025 (2)0.0168 (18)−0.0023 (17)0.0016 (16)0.0014 (17)
C50.025 (3)0.030 (3)0.022 (2)0.008 (2)0.000 (2)0.000 (2)
C60.027 (3)0.026 (3)0.028 (3)0.006 (2)0.000 (2)0.002 (2)
N20.020 (3)0.025 (2)0.0164 (19)−0.0032 (18)0.0019 (16)0.0007 (17)
C70.018 (3)0.023 (3)0.021 (2)0.000 (2)0.0055 (18)0.005 (2)
C80.021 (3)0.021 (2)0.034 (3)0.009 (2)0.000 (2)0.012 (2)
N1'0.018 (2)0.025 (2)0.0168 (18)−0.0023 (17)0.0016 (16)0.0014 (17)
C5'0.025 (3)0.030 (3)0.022 (2)0.008 (2)0.000 (2)0.000 (2)
C6'0.027 (3)0.026 (3)0.028 (3)0.006 (2)0.000 (2)0.002 (2)
N2'0.020 (3)0.025 (2)0.0164 (19)−0.0032 (18)0.0019 (16)0.0007 (17)
C7'0.018 (3)0.023 (3)0.021 (2)0.000 (2)0.0055 (18)0.005 (2)
C8'0.021 (3)0.021 (2)0.034 (3)0.009 (2)0.000 (2)0.012 (2)
C90.025 (2)0.034 (2)0.027 (2)−0.0067 (17)−0.0061 (16)0.0026 (16)

Geometric parameters (Å, °)

C1—C3i1.392 (5)C8—H8A0.9800
C1—C21.396 (4)C8—H8B0.9800
C1—H10.9500C8—H8C0.9800
C2—C31.391 (5)N1'—C5'1.3500
C2—H20.9500N1'—C7'1.3500
C3—C1i1.392 (5)C5'—C6'1.3500
C3—C41.507 (4)C5'—H5'0.9500
C4—N11.432 (4)C6'—N2'1.3500
C4—N1'1.512 (7)C6'—H6'0.9500
C4—H4A0.9900N2'—C7'1.3500
C4—H4B0.9900N2'—C91.384 (7)
C4—H4C0.9900C7'—C8'1.513 (15)
C4—H4D0.9900C8'—H8'10.9800
N1—C51.3500C8'—H8'20.9800
N1—C71.3500C8'—H8'30.9800
C5—C61.3500C9—H9A0.9800
C5—H50.9500C9—H9B0.9800
C6—N21.3500C9—H9C0.9800
C6—H60.9500C9—H9D0.9800
N2—C71.3500C9—H9E0.9800
N2—C91.468 (4)C9—H9F0.9800
C7—C81.492 (5)
C3i—C1—C2120.6 (3)N2—C7—C8125.2 (3)
C3i—C1—H1119.7N1—C7—C8126.8 (3)
C2—C1—H1119.7C5'—N1'—C7'108.0
C3—C2—C1120.1 (3)C5'—N1'—C4121.6 (6)
C3—C2—H2120.0C7'—N1'—C4130.4 (6)
C1—C2—H2120.0C6'—C5'—N1'108.0
C2—C3—C1i119.3 (3)C6'—C5'—H5'126.0
C2—C3—C4122.4 (3)N1'—C5'—H5'126.0
C1i—C3—C4118.3 (3)C5'—C6'—N2'108.0
N1—C4—C3112.1 (3)C5'—C6'—H6'126.0
C3—C4—N1'115.1 (4)N2'—C6'—H6'126.0
N1—C4—H4A109.2C7'—N2'—C6'108.0
C3—C4—H4A109.2C7'—N2'—C9124.8 (6)
N1'—C4—H4A129.4C6'—N2'—C9126.8 (6)
N1—C4—H4B109.2N2'—C7'—N1'108.0
C3—C4—H4B109.2N2'—C7'—C8'126.2 (8)
H4A—C4—H4B107.9N1'—C7'—C8'125.8 (8)
C3—C4—H4C108.5C7'—C8'—H8'1109.5
N1'—C4—H4C108.5C7'—C8'—H8'2109.5
C3—C4—H4D108.5H8'1—C8'—H8'2109.5
N1'—C4—H4D108.5C7'—C8'—H8'3109.5
H4C—C4—H4D107.5H8'1—C8'—H8'3109.5
C5—N1—C7108.0H8'2—C8'—H8'3109.5
C5—N1—C4124.6 (3)N2—C9—H9A109.5
C7—N1—C4127.2 (3)N2—C9—H9B109.5
N1—C5—C6108.0H9A—C9—H9B109.5
N1—C5—H5126.0N2—C9—H9C109.5
C6—C5—H5126.0H9A—C9—H9C109.5
N2—C6—C5108.0H9B—C9—H9C109.5
N2—C6—H6126.0N2'—C9—H9D109.5
C5—C6—H6126.0N2'—C9—H9E109.5
C6—N2—C7108.0H9D—C9—H9E109.5
C6—N2—C9124.4 (3)N2'—C9—H9F109.5
C7—N2—C9127.6 (3)H9D—C9—H9F109.5
N2—C7—N1108.0H9E—C9—H9F109.5
C3i—C1—C2—C3−0.1 (6)C4—N1—C7—C8−3.3 (5)
C1—C2—C3—C1i0.1 (6)N1—C4—N1'—C5'170.1 (11)
C1—C2—C3—C4179.8 (3)C3—C4—N1'—C5'−98.3 (6)
C2—C3—C4—N130.3 (5)N1—C4—N1'—C7'−9.2 (5)
C1i—C3—C4—N1−150.0 (3)C3—C4—N1'—C7'82.4 (8)
C2—C3—C4—N1'−3.4 (6)C7'—N1'—C5'—C6'0.0
C1i—C3—C4—N1'176.3 (4)C4—N1'—C5'—C6'−179.5 (8)
C3—C4—N1—C576.5 (4)N1'—C5'—C6'—N2'0.0
N1'—C4—N1—C5178.8 (8)C5'—C6'—N2'—C7'0.0
C3—C4—N1—C7−97.3 (3)C5'—C6'—N2'—C9−173.4 (8)
N1'—C4—N1—C74.9 (7)C6'—N2'—C7'—N1'0.0
C7—N1—C5—C60.0C9—N2'—C7'—N1'173.5 (8)
C4—N1—C5—C6−174.8 (3)C6'—N2'—C7'—C8'179.7 (11)
N1—C5—C6—N20.0C9—N2'—C7'—C8'−6.8 (12)
C5—C6—N2—C70.0C5'—N1'—C7'—N2'0.0
C5—C6—N2—C9179.0 (3)C4—N1'—C7'—N2'179.4 (8)
C6—N2—C7—N10.0C5'—N1'—C7'—C8'−179.7 (11)
C9—N2—C7—N1−179.0 (4)C4—N1'—C7'—C8'−0.3 (12)
C6—N2—C7—C8178.0 (4)C7'—N2'—C9—N26.6 (5)
C9—N2—C7—C8−1.0 (5)C6'—N2'—C9—N2179.0 (11)
C5—N1—C7—N20.0C6—N2—C9—N2'171.4 (8)
C4—N1—C7—N2174.7 (3)C7—N2—C9—N2'−9.8 (7)
C5—N1—C7—C8−177.9 (4)

Symmetry codes: (i) −x+1, −y, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: TK2494).

References

  • Barbour, L. J. (2001). J. Supramol. Chem.1, 189–191.
  • Bruker (2008). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Dobrzańska, L. (2005). Acta Cryst. E61, o4113–o4115.
  • Ganesan, K., Alias, Y. & Ng, S. W. (2008). Acta Cryst. C64, o478–o480. [PubMed]
  • Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Westrip, S. P. (2009). publCIF In preparation.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography