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

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ISSN: 2056-9890

1-(5,5-Di­meth­­oxy­pent­yl)-3-methyl­imidazolium-2-carboxyl­ate

aIKFT, KIT-Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
*Correspondence e-mail: olaf.walter@kit.edu

(Received 23 September 2013; accepted 1 October 2013; online 5 October 2013)

The title compound, C12H20N2O4, represents one example of a zwitterionic imidazolium salt with a carboxyl­ate group at the 2-position of the imidazolium ring. The dihedral angle between the heterocyclic ring and the carboxyl­ate group is 31.3 (1)°. The side chain linking the N atom of the ring and the methine C atom has a gaucheantianti conformation [torsion angles = −60.3 (2), −175.7 (2) and 178.7 (2)°, respectively]. In the crystal, mol­ecules are linked by short C—H⋯O hydrogen bonds involving the C—H groups in the aromatic ring to generate (001) sheets.

Related literature

For related zwitterionic structures, see: Gurau et al. (2011[Gurau, G., Rodriguez, H., Kelley, S. P., Janiczek, P., Kalb, R. S. & Rogers, R. D. (2011). Angew. Chem. Int. Ed. Engl. 50, 12024-12026.]); Holbrey et al. (2003[Holbrey, J. D., Reichert, W. M., Tkatchenko, I., Bouajila, E., Walter, O., Tommasi, I. & Rogers, R. D. (2003). Chem. Commun. pp. 28-29.]); Smiglak et al. (2007[Smiglak, M., Holbrey, J. D., Griffin, S. T., Reichert, W. M., Swatloski, R. P., Katritzky, A. R., Yang, H., Zhang, D., Kirichenko, K. & Rogers, R. D. (2007). Green Chem. 9, 90-98.]); Reichert et al. (2010[Reichert, W. M., Trulove, P. C. & De Long, H. C. (2010). Acta Cryst. E66, o591.]).

[Scheme 1]

Experimental

Crystal data
  • C12H20N2O4

  • Mr = 256.30

  • Triclinic, [P \overline 1]

  • a = 7.1943 (8) Å

  • b = 7.3259 (8) Å

  • c = 13.2263 (15) Å

  • α = 85.124 (2)°

  • β = 85.542 (2)°

  • γ = 72.938 (2)°

  • V = 662.98 (13) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 200 K

  • 0.3 × 0.15 × 0.15 mm

Data collection
  • Siemens SMART CCD 1000 diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 1997[Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.940, Tmax = 1.000

  • 8022 measured reflections

  • 3192 independent reflections

  • 1962 reflections with I > 2σ(I)

  • Rint = 0.023

Refinement
  • R[F2 > 2σ(F2)] = 0.054

  • wR(F2) = 0.178

  • S = 1.03

  • 3192 reflections

  • 171 parameters

  • Only H-atom displacement parameters refined

  • Δρmax = 0.27 e Å−3

  • Δρmin = −0.32 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H3⋯O2i 0.93 2.30 3.141 (2) 151
C4—H4⋯O1ii 0.93 2.30 3.127 (2) 148
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z.

Data collection: SMART (Bruker, 1997[Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SMART; data reduction: SAINT (Bruker, 1997[Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2013[Sheldrick, G. M. (2013). SHELXL2013. University of Göttingen, Germany.]); molecular graphics: XPMA (Zsolnai, 1996[Zsolnai, L. (1996). XPMA. University of Heidelberg, Germany.]) and ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

1-(5,5-Dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate is one example for only a few in the literature reported zwitterions consisting of a positively charged imidazolium ring carrying in 2-position a carboxylato group (see Figure 1). The C—O bond distances in the carboxylato group are determined to 1.234 (2) and 1.238 (8) Å and are therefor comparable to those of Holbrey et al. (2003), Gurau et al. (2011), or Smiglak et al. (2007). Within the imidazoliumcarboxylate-unit complete delocalization of the π-electrons is possible. However, the embedding of the carboxylato group of 1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate in the formation of intermolecular H-bridge bonds (H3···O2 2.30 Å and H4···O1 2.30 Å) causes a distortion from the planarity (torsion angle N1—C1—C2—O1 -29.6 °, see figure 2, 3). The imidazolium rings are placed approximately in the a,b-plane of the elementary cell around the middle of the c axis and the center of the cell whereas the in 1-position placed 5,5-dimethoxypentyl-substituent is oriented parallelly to the c axis perpendicularly to the imidazole ring monstrating versus the next layer of imidazolium rings in the next cell (figure 3). By this arrangement the 5,5-dimethoxypentyl-substituents form an unpolar region in the cell enabling the formation of van-der-Waals interactions to those of neighboured molecules. Another example of a zwitterionic imidazolium based molecule with to different substituents in 1,3-position of the imidazolium unit is reported in Reichert et al. (2010). In the reported structure the negative charge equilibrating the positive one of the imidazolium ring is a 3-sulfonatopropyl-group. The charges are separated, due to this and the shortness of the propyl-group the complete molecular arrangment in the cell is different and not comparable. However a comparison of the structural features of the imidazolium ring in 1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate to those of the other in the literature reported imidazolium based carboxylates show a general and high congruency.

Related literature top

For related zwitterion structures, see: Gurau et al. (2011); Holbrey et al. (2003); Smiglak et al. (2007); Reichert et al. (2010).

Experimental top

1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate is obtained from the reaction of 2.0 g (7.8 mmol) 1-(5,5-dimethoxypentyl)-imidazole heated to 120° C in an autoclave for 3 h together with 10 ml of methanol and 10 ml of dimethylcarbonate after removal of the solvent and re-crystallization from small amounts of methanol in 55% yield. 1-(5,5-dimethoxypentyl)-imidazole has been prepared by alkylation of imidazole with 1-chloro-5,5-dimethoxypentane.

Refinement top

The positions of all H atoms are calculated on geometrical positions according to the hybridization of the atoms they are bound to. The isotropic U values of the hydrogen atoms are refined group-wisely.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2013); molecular graphics: XPMA (Zsolnai, 1996) and ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. : View to the molecular structure of 1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate; ellipsoids at 50% probability level
[Figure 2] Fig. 2. : Visualization of the H-bridge bond system of 1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate in the crystal; ellipsoids at 50% probability level
[Figure 3] Fig. 3. : Molecular arrangement of 1-(5,5-dimethoxypentyl)-3-methyl-imidazolium-2-carboxylate in the cell; ellipsoids at 50% probability level
1-(5,5-Dimethoxypentyl)-3-methylimidazolium-2-carboxylate top
Crystal data top
C12H20N2O4Z = 2
Mr = 256.30F(000) = 276
Triclinic, P1Dx = 1.284 Mg m3
a = 7.1943 (8) ÅMo Kα radiation, λ = 0.71073 Å
b = 7.3259 (8) ÅCell parameters from 49 reflections
c = 13.2263 (15) Åθ = 2.8–42.3°
α = 85.124 (2)°µ = 0.10 mm1
β = 85.542 (2)°T = 200 K
γ = 72.938 (2)°Block, colourless
V = 662.98 (13) Å30.3 × 0.15 × 0.15 mm
Data collection top
Siemens SMART CCD 1000
diffractometer
3192 independent reflections
Radiation source: fine-focus sealed tube1962 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
Detector resolution: 8 pixels mm-1θmax = 28.3°, θmin = 1.6°
ω scanh = 99
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
k = 99
Tmin = 0.940, Tmax = 1l = 1717
8022 measured reflections
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)] = 0.054Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.178Only H-atom displacement parameters refined
S = 1.03 w = 1/[σ2(Fo2) + (0.1021P)2]
where P = (Fo2 + 2Fc2)/3
3192 reflections(Δ/σ)max < 0.001
171 parametersΔρmax = 0.27 e Å3
0 restraintsΔρmin = 0.32 e Å3
Crystal data top
C12H20N2O4γ = 72.938 (2)°
Mr = 256.30V = 662.98 (13) Å3
Triclinic, P1Z = 2
a = 7.1943 (8) ÅMo Kα radiation
b = 7.3259 (8) ŵ = 0.10 mm1
c = 13.2263 (15) ÅT = 200 K
α = 85.124 (2)°0.3 × 0.15 × 0.15 mm
β = 85.542 (2)°
Data collection top
Siemens SMART CCD 1000
diffractometer
3192 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
1962 reflections with I > 2σ(I)
Tmin = 0.940, Tmax = 1Rint = 0.023
8022 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0540 restraints
wR(F2) = 0.178Only H-atom displacement parameters refined
S = 1.03Δρmax = 0.27 e Å3
3192 reflectionsΔρmin = 0.32 e Å3
171 parameters
Special details top

Experimental. Spectroscopic data: 1H NMR (CDCl3): δ = 6.93, s (br), 1H, CH(arom); 6.91 (br), s, 1H, CH(arom); 4.51, t, 3JHH= 7.4 Hz, 2H, NCH2; 4.26, t, 3JHH= 5.5 Hz, 1H, COH; 4.06, s (br), 3H, NCH3; 3.24, s, 6H, OCH3; 1.84, p, 3JHH= 7.4 Hz, 2H, CH2; 1.56, m, 2H, CH2; 1.35, m, CH2.

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. The structure was solved by direct methods and refined to an optimum R1 value with SHELXL. The data of the structure have been deposited at the CCDC with the reference number 962824.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.1515 (2)0.2046 (2)0.42195 (13)0.0450 (4)
O20.3946 (2)0.4369 (2)0.35645 (13)0.0472 (4)
O30.2709 (3)0.4306 (3)0.04153 (13)0.0594 (5)
O40.2379 (3)0.1828 (3)0.13125 (14)0.0745 (6)
N10.3940 (2)0.0490 (2)0.36421 (11)0.0254 (4)
N20.6433 (2)0.1977 (2)0.38760 (11)0.0252 (4)
C10.4498 (3)0.1435 (2)0.37745 (13)0.0239 (4)
C20.3182 (3)0.2742 (3)0.38566 (15)0.0298 (5)
C30.5536 (3)0.1147 (3)0.36567 (15)0.0297 (5)
H30.55450.24180.35720.030 (4)*
C40.7090 (3)0.0391 (3)0.38158 (14)0.0303 (5)
H40.83660.03770.38740.030 (4)*
C50.7684 (3)0.3936 (3)0.40763 (17)0.0357 (5)
H5A0.72510.44680.47070.050 (4)*
H5B0.90050.39160.41170.050 (4)*
H5C0.76160.47040.35350.050 (4)*
C60.1956 (3)0.1756 (3)0.34690 (15)0.0304 (5)
H6A0.19400.30760.35100.040 (2)*
H6B0.10560.14650.39990.040 (2)*
C70.1284 (3)0.1521 (3)0.24391 (16)0.0374 (5)
H7A0.12520.02100.24160.040 (2)*
H7B0.00360.23450.23740.040 (2)*
C80.2543 (3)0.1980 (3)0.15374 (17)0.0438 (6)
H8A0.26560.32580.15800.040 (2)*
H8B0.38380.10890.15660.040 (2)*
C90.1725 (4)0.1868 (4)0.05333 (18)0.0491 (6)
H9A0.04140.27340.05180.040 (2)*
H9B0.16350.05810.04910.040 (2)*
C100.2915 (4)0.2362 (4)0.03937 (18)0.0577 (7)
H100.42880.16720.03030.042 (6)*
C110.4004 (5)0.4901 (6)0.1162 (2)0.0980 (13)
H11A0.53220.41700.10430.122 (6)*
H11B0.38650.62350.11150.122 (6)*
H11C0.36920.46950.18280.122 (6)*
C120.0419 (5)0.2754 (5)0.1545 (2)0.0674 (8)
H12A0.04350.22220.11000.122 (6)*
H12B0.02420.25700.22370.122 (6)*
H12C0.01250.40980.14550.122 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0251 (8)0.0351 (9)0.0739 (12)0.0105 (6)0.0030 (7)0.0031 (7)
O20.0530 (10)0.0268 (8)0.0648 (11)0.0175 (7)0.0080 (8)0.0088 (7)
O30.0608 (12)0.0811 (14)0.0435 (10)0.0348 (10)0.0001 (8)0.0047 (9)
O40.0951 (16)0.0718 (14)0.0456 (11)0.0059 (12)0.0002 (11)0.0108 (9)
N10.0264 (8)0.0199 (8)0.0290 (8)0.0056 (6)0.0007 (6)0.0009 (6)
N20.0236 (8)0.0233 (8)0.0276 (8)0.0058 (6)0.0001 (6)0.0000 (6)
C10.0248 (9)0.0210 (9)0.0248 (9)0.0053 (7)0.0010 (7)0.0006 (7)
C20.0325 (11)0.0247 (10)0.0336 (11)0.0114 (8)0.0063 (8)0.0051 (8)
C30.0342 (11)0.0243 (10)0.0341 (11)0.0140 (8)0.0013 (8)0.0026 (8)
C40.0285 (10)0.0331 (11)0.0327 (11)0.0147 (9)0.0006 (8)0.0019 (8)
C50.0301 (11)0.0263 (11)0.0453 (13)0.0012 (8)0.0043 (9)0.0042 (9)
C60.0272 (10)0.0211 (9)0.0390 (11)0.0015 (8)0.0019 (8)0.0004 (8)
C70.0345 (11)0.0314 (11)0.0447 (13)0.0078 (9)0.0075 (9)0.0046 (9)
C80.0398 (13)0.0454 (13)0.0421 (13)0.0077 (10)0.0037 (10)0.0043 (10)
C90.0574 (15)0.0446 (14)0.0436 (14)0.0128 (12)0.0061 (11)0.0032 (10)
C100.0615 (17)0.0628 (18)0.0388 (14)0.0021 (14)0.0043 (12)0.0029 (12)
C110.079 (2)0.180 (4)0.0543 (19)0.076 (3)0.0008 (16)0.022 (2)
C120.082 (2)0.082 (2)0.0481 (16)0.0391 (18)0.0070 (15)0.0028 (14)
Geometric parameters (Å, º) top
O1—C21.234 (2)C6—C71.520 (3)
O2—C21.238 (2)C6—H6A0.9700
O3—C101.386 (3)C6—H6B0.9700
O3—C111.433 (3)C7—C81.516 (3)
O4—C121.419 (3)C7—H7A0.9700
O4—C101.421 (3)C7—H7B0.9700
N1—C11.348 (2)C8—C91.512 (3)
N1—C31.371 (2)C8—H8A0.9700
N1—C61.479 (2)C8—H8B0.9700
N2—C11.345 (2)C9—C101.520 (3)
N2—C41.372 (2)C9—H9A0.9700
N2—C51.468 (2)C9—H9B0.9700
C1—C21.524 (3)C10—H100.9800
C3—C41.349 (3)C11—H11A0.9600
C3—H30.9300C11—H11B0.9600
C4—H40.9300C11—H11C0.9600
C5—H5A0.9600C12—H12A0.9600
C5—H5B0.9600C12—H12B0.9600
C5—H5C0.9600C12—H12C0.9600
C10—O3—C11112.8 (2)C6—C7—H7A108.6
C12—O4—C10114.0 (2)C8—C7—H7B108.6
C1—N1—C3109.36 (15)C6—C7—H7B108.6
C1—N1—C6127.21 (16)H7A—C7—H7B107.6
C3—N1—C6123.40 (15)C9—C8—C7112.45 (19)
C1—N2—C4109.59 (15)C9—C8—H8A109.1
C1—N2—C5126.70 (15)C7—C8—H8A109.1
C4—N2—C5123.63 (15)C9—C8—H8B109.1
N2—C1—N1106.65 (15)C7—C8—H8B109.1
N2—C1—C2126.40 (16)H8A—C8—H8B107.8
N1—C1—C2126.86 (16)C8—C9—C10114.3 (2)
O1—C2—O2128.94 (19)C8—C9—H9A108.7
O1—C2—C1115.65 (17)C10—C9—H9A108.7
O2—C2—C1115.39 (17)C8—C9—H9B108.7
C4—C3—N1107.34 (16)C10—C9—H9B108.7
C4—C3—H3126.3H9A—C9—H9B107.6
N1—C3—H3126.3O3—C10—O4112.1 (2)
C3—C4—N2107.05 (16)O3—C10—C9107.4 (2)
C3—C4—H4126.5O4—C10—C9112.8 (2)
N2—C4—H4126.5O3—C10—H10108.1
N2—C5—H5A109.5O4—C10—H10108.1
N2—C5—H5B109.5C9—C10—H10108.1
H5A—C5—H5B109.5O3—C11—H11A109.5
N2—C5—H5C109.5O3—C11—H11B109.5
H5A—C5—H5C109.5H11A—C11—H11B109.5
H5B—C5—H5C109.5O3—C11—H11C109.5
N1—C6—C7111.91 (15)H11A—C11—H11C109.5
N1—C6—H6A109.2H11B—C11—H11C109.5
C7—C6—H6A109.2O4—C12—H12A109.5
N1—C6—H6B109.2O4—C12—H12B109.5
C7—C6—H6B109.2H12A—C12—H12B109.5
H6A—C6—H6B107.9O4—C12—H12C109.5
C8—C7—C6114.69 (18)H12A—C12—H12C109.5
C8—C7—H7A108.6H12B—C12—H12C109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.932.303.141 (2)151
C4—H4···O1ii0.932.303.127 (2)148
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.932.303.141 (2)151
C4—H4···O1ii0.932.303.127 (2)148
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z.
 

Acknowledgements

The author gratefully acknowledges financial support for this work from the Karlsruhe Institute for Technology.

References

First citationBruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals
First citationGurau, G., Rodriguez, H., Kelley, S. P., Janiczek, P., Kalb, R. S. & Rogers, R. D. (2011). Angew. Chem. Int. Ed. Engl. 50, 12024–12026.  Web of Science CSD CrossRef CAS PubMed
First citationHolbrey, J. D., Reichert, W. M., Tkatchenko, I., Bouajila, E., Walter, O., Tommasi, I. & Rogers, R. D. (2003). Chem. Commun. pp. 28–29.  Web of Science CSD CrossRef
First citationReichert, W. M., Trulove, P. C. & De Long, H. C. (2010). Acta Cryst. E66, o591.  Web of Science CSD CrossRef IUCr Journals
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSheldrick, G. M. (2013). SHELXL2013. University of Göttingen, Germany.
First citationSmiglak, M., Holbrey, J. D., Griffin, S. T., Reichert, W. M., Swatloski, R. P., Katritzky, A. R., Yang, H., Zhang, D., Kirichenko, K. & Rogers, R. D. (2007). Green Chem. 9, 90–98.  Web of Science CSD CrossRef CAS
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals
First citationZsolnai, L. (1996). XPMA. University of Heidelberg, Germany.

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