organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

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

aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: puvanes5881@yahoo.com

(Received 16 August 2010; accepted 19 August 2010; online 28 August 2010)

In the solid form of the title imidazolium-based ionic liquid salt, C18H24N42+·2CF3SO3, the complete cation is generated by a crystallographic inversion centre. The five-membered imidazole ring is approximately perpendicular to the six-membered phenyl­ene ring [dihedral angle = 85.11 (11)°]. In the crystal, the components are linked by C—H⋯O interactions.

Related literature

For background to imidazolium-based ionic liquid salts, see: Ganesan et al. (2008[Ganesan, K., Alias, Y. & Ng, S. W. (2008). Acta Cryst. C64, o478-o480.]); Puvaneswary et al. (2009a[Puvaneswary, S., Alias, Y. & Ng, S. W. (2009a). Acta Cryst. E65, o1828.],b[Puvaneswary, S., Alias, Y. & Ng, S. W. (2009b). Acta Cryst. E65, o1829.],c[Puvaneswary, S., Alias, Y. & Ng, S. W. (2009c). Acta Cryst. E65, o1830.]).

[Scheme 1]

Experimental

Crystal data
  • C18H24N42+·2CF3O3S

  • Mr = 594.55

  • Triclinic, [P \overline 1]

  • a = 7.3054 (1) Å

  • b = 8.0645 (2) Å

  • c = 11.3548 (2) Å

  • α = 89.946 (1)°

  • β = 76.653 (1)°

  • γ = 75.213 (1)°

  • V = 628.14 (2) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 100 K

  • 0.31 × 0.19 × 0.04 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.912, Tmax = 0.988

  • 5105 measured reflections

  • 2273 independent reflections

  • 1982 reflections with I > 2σ(I)

  • Rint = 0.021

Refinement
  • R[F2 > 2σ(F2)] = 0.042

  • wR(F2) = 0.103

  • S = 1.16

  • 2273 reflections

  • 174 parameters

  • H-atom parameters constrained

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.37 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C6—H6A⋯O2i 0.99 2.35 3.251 (3) 152
C3—H3A⋯O2ii 0.98 2.59 3.424 (4) 144
C1—H1C⋯O2ii 0.98 2.49 3.296 (3) 139
C1—H1B⋯O1iii 0.98 2.36 3.293 (3) 159
C1—H1A⋯O1iv 0.98 2.52 3.164 (3) 123
Symmetry codes: (i) -x+2, -y, -z+1; (ii) -x+1, -y, -z+1; (iii) x-1, y, z; (iv) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: X-SEED (Barbour, 2001[Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

Crystal structures of similar symmetrical compunds have been reported from our previous studies (Ganesan, et al., 2008; Puvaneswary et al., 2009a; 2009b; 2009c). As part of our ongoing research into imidazolium-based ionic liquids, we have synthesized 1,1',2,2'-tetramethyl-3,3'-(p-phenylenedimethylene)diimidazolium salt with trifluoromethanesulfonate anion.

The neighbouring cations in the title compund are held together via C–H···O hydrogen bonds in opposite directions through imidazole rings to CF3SO3- anions and these hydrogen bonds stabilize the crystal structure.

Related literature top

For background to imidazolium-based ionic liquid salts, see: Ganesan et al. (2008); Puvaneswary et al. (2009a,b,c).

Experimental top

α,α-Dibromo-p-xylene (1.26 g, 4.77 mmol) and 1,2-dimethylimidazole (0.96 g, 9.99 mmol) were refluxed in DMF (50 ml) for 3 h. The product that separated from solution was collected and washed with ether. Crystals of the bromide salt were grown from its solution in water (Puvaneswary et al., 2009a).

The bromide salt (0.50 g, 1.10 mmol) and lithium trifluoromethanesulfonate (0.36 g, 2.31 mmol) were stirred in water (100 ml) for 24 h. Colourless crystals were obtained by slow evaporation of the solution (Melting point: 92–94°C).

Refinement top

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

Structure description top

Crystal structures of similar symmetrical compunds have been reported from our previous studies (Ganesan, et al., 2008; Puvaneswary et al., 2009a; 2009b; 2009c). As part of our ongoing research into imidazolium-based ionic liquids, we have synthesized 1,1',2,2'-tetramethyl-3,3'-(p-phenylenedimethylene)diimidazolium salt with trifluoromethanesulfonate anion.

The neighbouring cations in the title compund are held together via C–H···O hydrogen bonds in opposite directions through imidazole rings to CF3SO3- anions and these hydrogen bonds stabilize the crystal structure.

For background to imidazolium-based ionic liquid salts, see: Ganesan et al. (2008); Puvaneswary et al. (2009a,b,c).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Thermal ellipsoid plot of the title compund at the 50% probability level. H atoms are drawn as spheres of arbitrary radius.
1,1',2,2'-Tetramethyl-3,3'-(p-phenylenedimethylene)diimidazol-1-ium bis(trifluoromethanesulfonate) top
Crystal data top
C18H24N42+·2CF3O3SZ = 1
Mr = 594.55F(000) = 306
Triclinic, P1Dx = 1.572 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.3054 (1) ÅCell parameters from 1992 reflections
b = 8.0645 (2) Åθ = 2.6–29.0°
c = 11.3548 (2) ŵ = 0.30 mm1
α = 89.946 (1)°T = 100 K
β = 76.653 (1)°Plate, colourless
γ = 75.213 (1)°0.31 × 0.19 × 0.04 mm
V = 628.14 (2) Å3
Data collection top
Bruker APEXII CCD
diffractometer
2273 independent reflections
Radiation source: fine-focus sealed tube1982 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
φ and ω scansθmax = 25.3°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 88
Tmin = 0.912, Tmax = 0.988k = 99
5105 measured reflectionsl = 1313
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.103H-atom parameters constrained
S = 1.16 w = 1/[σ2(Fo2) + (0.0241P)2 + 1.0056P]
where P = (Fo2 + 2Fc2)/3
2273 reflections(Δ/σ)max < 0.001
174 parametersΔρmax = 0.33 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
C18H24N42+·2CF3O3Sγ = 75.213 (1)°
Mr = 594.55V = 628.14 (2) Å3
Triclinic, P1Z = 1
a = 7.3054 (1) ÅMo Kα radiation
b = 8.0645 (2) ŵ = 0.30 mm1
c = 11.3548 (2) ÅT = 100 K
α = 89.946 (1)°0.31 × 0.19 × 0.04 mm
β = 76.653 (1)°
Data collection top
Bruker APEXII CCD
diffractometer
2273 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1982 reflections with I > 2σ(I)
Tmin = 0.912, Tmax = 0.988Rint = 0.021
5105 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0420 restraints
wR(F2) = 0.103H-atom parameters constrained
S = 1.16Δρmax = 0.33 e Å3
2273 reflectionsΔρmin = 0.37 e Å3
174 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
N10.1441 (3)0.2762 (3)0.18655 (19)0.0160 (5)
N20.3402 (3)0.2113 (3)0.30441 (19)0.0154 (5)
C10.0172 (4)0.3018 (3)0.4080 (2)0.0184 (6)
H1A0.11680.40260.39490.028*
H1B0.02510.32410.48100.028*
H1C0.07180.20220.41840.028*
C20.1513 (4)0.2664 (3)0.3023 (2)0.0153 (5)
C30.0369 (4)0.3301 (4)0.1445 (3)0.0214 (6)
H3A0.11690.24980.17030.032*
H3B0.00500.33040.05580.032*
H3C0.10930.44590.17930.032*
C40.3304 (4)0.2260 (3)0.1129 (2)0.0192 (6)
H40.36510.22140.02680.023*
C50.4525 (4)0.1851 (3)0.1863 (2)0.0191 (6)
H50.59060.14540.16200.023*
C60.4164 (4)0.1924 (3)0.4137 (2)0.0165 (6)
H6A0.53890.09920.39700.020*
H6B0.32140.15750.47960.020*
C70.4564 (3)0.3550 (3)0.4568 (2)0.0144 (5)
C80.4553 (4)0.4977 (3)0.3878 (2)0.0166 (6)
H80.42470.49740.31090.020*
C90.5011 (4)0.3589 (3)0.5692 (2)0.0155 (5)
H90.50180.26240.61730.019*
S11.07181 (10)0.18928 (9)0.76648 (6)0.01802 (18)
F10.7150 (2)0.1636 (2)0.78601 (16)0.0331 (4)
F20.7393 (2)0.3543 (2)0.91048 (16)0.0334 (4)
F30.8292 (2)0.0858 (2)0.94182 (14)0.0272 (4)
O11.0372 (3)0.3265 (3)0.68688 (17)0.0283 (5)
O21.1362 (3)0.0188 (3)0.70802 (19)0.0332 (5)
O31.1741 (3)0.2164 (3)0.85592 (18)0.0262 (5)
C100.8268 (4)0.1991 (3)0.8556 (2)0.0204 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0189 (12)0.0156 (11)0.0150 (11)0.0052 (9)0.0060 (9)0.0006 (9)
N20.0154 (11)0.0174 (12)0.0136 (11)0.0046 (9)0.0035 (9)0.0001 (9)
C10.0180 (14)0.0191 (14)0.0177 (13)0.0044 (11)0.0039 (11)0.0009 (11)
C20.0188 (13)0.0130 (13)0.0162 (13)0.0063 (11)0.0059 (11)0.0002 (10)
C30.0221 (15)0.0233 (15)0.0215 (14)0.0053 (12)0.0111 (12)0.0003 (11)
C40.0247 (15)0.0190 (14)0.0136 (13)0.0081 (12)0.0009 (11)0.0017 (10)
C50.0173 (14)0.0215 (14)0.0174 (14)0.0062 (11)0.0007 (11)0.0032 (11)
C60.0160 (13)0.0192 (14)0.0157 (13)0.0050 (11)0.0060 (10)0.0020 (10)
C70.0073 (12)0.0192 (13)0.0151 (13)0.0022 (10)0.0011 (10)0.0011 (10)
C80.0150 (13)0.0227 (14)0.0123 (12)0.0038 (11)0.0047 (10)0.0009 (10)
C90.0131 (13)0.0171 (13)0.0155 (13)0.0022 (10)0.0041 (10)0.0029 (10)
S10.0180 (4)0.0213 (4)0.0143 (3)0.0061 (3)0.0019 (3)0.0007 (3)
F10.0283 (10)0.0448 (11)0.0367 (10)0.0189 (8)0.0182 (8)0.0115 (8)
F20.0254 (9)0.0241 (9)0.0409 (11)0.0004 (7)0.0038 (8)0.0048 (8)
F30.0329 (10)0.0300 (9)0.0213 (9)0.0150 (8)0.0044 (7)0.0088 (7)
O10.0382 (12)0.0340 (12)0.0190 (10)0.0182 (10)0.0098 (9)0.0098 (9)
O20.0293 (12)0.0287 (12)0.0355 (13)0.0059 (9)0.0024 (10)0.0137 (10)
O30.0222 (11)0.0357 (12)0.0227 (11)0.0089 (9)0.0081 (8)0.0034 (9)
C100.0216 (15)0.0187 (14)0.0209 (14)0.0047 (11)0.0060 (12)0.0023 (11)
Geometric parameters (Å, º) top
N1—C21.329 (3)C6—C71.520 (4)
N1—C41.382 (3)C6—H6A0.9900
N1—C31.471 (3)C6—H6B0.9900
N2—C21.343 (3)C7—C91.390 (4)
N2—C51.386 (3)C7—C81.391 (4)
N2—C61.466 (3)C8—C9i1.392 (4)
C1—C21.475 (4)C8—H80.9500
C1—H1A0.9800C9—C8i1.392 (4)
C1—H1B0.9800C9—H90.9500
C1—H1C0.9800S1—O11.438 (2)
C3—H3A0.9800S1—O31.439 (2)
C3—H3B0.9800S1—O21.442 (2)
C3—H3C0.9800S1—C101.824 (3)
C4—C51.339 (4)F1—C101.338 (3)
C4—H40.9500F2—C101.331 (3)
C5—H50.9500F3—C101.338 (3)
C2—N1—C4109.9 (2)N2—C6—C7113.6 (2)
C2—N1—C3124.5 (2)N2—C6—H6A108.8
C4—N1—C3125.6 (2)C7—C6—H6A108.8
C2—N2—C5109.0 (2)N2—C6—H6B108.8
C2—N2—C6125.6 (2)C7—C6—H6B108.8
C5—N2—C6125.3 (2)H6A—C6—H6B107.7
C2—C1—H1A109.5C9—C7—C8118.8 (2)
C2—C1—H1B109.5C9—C7—C6118.2 (2)
H1A—C1—H1B109.5C8—C7—C6123.0 (2)
C2—C1—H1C109.5C7—C8—C9i120.3 (2)
H1A—C1—H1C109.5C7—C8—H8119.8
H1B—C1—H1C109.5C9i—C8—H8119.8
N1—C2—N2107.0 (2)C7—C9—C8i120.9 (2)
N1—C2—C1126.3 (2)C7—C9—H9119.5
N2—C2—C1126.6 (2)C8i—C9—H9119.5
N1—C3—H3A109.5O1—S1—O3115.23 (12)
N1—C3—H3B109.5O1—S1—O2115.05 (13)
H3A—C3—H3B109.5O3—S1—O2114.61 (13)
N1—C3—H3C109.5O1—S1—C10102.57 (13)
H3A—C3—H3C109.5O3—S1—C10103.71 (12)
H3B—C3—H3C109.5O2—S1—C10103.25 (13)
C5—C4—N1106.8 (2)F2—C10—F3107.4 (2)
C5—C4—H4126.6F2—C10—F1107.8 (2)
N1—C4—H4126.6F3—C10—F1107.1 (2)
C4—C5—N2107.3 (2)F2—C10—S1111.33 (19)
C4—C5—H5126.4F3—C10—S1111.72 (19)
N2—C5—H5126.4F1—C10—S1111.34 (19)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6A···O2ii0.992.353.251 (3)152
C3—H3A···O2iii0.982.593.424 (4)144
C1—H1C···O2iii0.982.493.296 (3)139
C1—H1B···O1iv0.982.363.293 (3)159
C1—H1A···O1i0.982.523.164 (3)123
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+2, y, z+1; (iii) x+1, y, z+1; (iv) x1, y, z.

Experimental details

Crystal data
Chemical formulaC18H24N42+·2CF3O3S
Mr594.55
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)7.3054 (1), 8.0645 (2), 11.3548 (2)
α, β, γ (°)89.946 (1), 76.653 (1), 75.213 (1)
V3)628.14 (2)
Z1
Radiation typeMo Kα
µ (mm1)0.30
Crystal size (mm)0.31 × 0.19 × 0.04
Data collection
DiffractometerBruker APEXII CCD
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.912, 0.988
No. of measured, independent and
observed [I > 2σ(I)] reflections
5105, 2273, 1982
Rint0.021
(sin θ/λ)max1)0.600
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.042, 0.103, 1.16
No. of reflections2273
No. of parameters174
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.33, 0.37

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6A···O2i0.992.353.251 (3)151.6
C3—H3A···O2ii0.982.593.424 (4)143.6
C1—H1C···O2ii0.982.493.296 (3)139.2
C1—H1B···O1iii0.982.363.293 (3)158.8
C1—H1A···O1iv0.982.523.164 (3)122.8
Symmetry codes: (i) x+2, y, z+1; (ii) x+1, y, z+1; (iii) x1, y, z; (iv) x+1, y+1, z+1.
 

Acknowledgements

The authors would like to thank the University of Malaya for the financial support (grant Nos. RG062–09SUS and TA021–2009A).

References

First citationBarbour, L. J. (2001). J. Supramol. Chem. 1, 189–191.  CrossRef CAS Google Scholar
First citationBruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGanesan, K., Alias, Y. & Ng, S. W. (2008). Acta Cryst. C64, o478–o480.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationPuvaneswary, S., Alias, Y. & Ng, S. W. (2009a). Acta Cryst. E65, o1828.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationPuvaneswary, S., Alias, Y. & Ng, S. W. (2009b). Acta Cryst. E65, o1829.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationPuvaneswary, S., Alias, Y. & Ng, S. W. (2009c). Acta Cryst. E65, o1830.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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