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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 67| Part 4| April 2011| Pages o996-o997
doi:10.1107/S1600536811010774

2-Ethyl-1H-imidazole-4-carboxyl­ate monohydrate

Shi-Jie Li,a Juan-Hua Liu,a Wen-Dong Song,b* Xiao-Fei Lic and Dong-Liang Miaoa

aCollege of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China, bCollege of Science, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China, and cCollege of Agriculture, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China
*Correspondence e-mail: songwd60@163.com

(Received 9 March 2011; accepted 23 March 2011; online 31 March 2011)

In the title compound, C7H8N2O4·H2O, the imidazole N atom is protonated and one of the carboxyl­ate groups is deprontonated, forming a zwitterion. The two carboxyl groups are are approximately coplanar with the imidazole ring [O—C—C—C torsion angles = −176.8 (2) and 2.9 (4)° for one group and −4.6 (3) and 176.4 (2)° for the other] and have an intra­molecular O—H⋯O hydrogen bond between them. The water mol­ecule is linked to the organic mol­ecules via an N—H⋯O hydrogen bonds. Inter­molecular O—H⋯O and N—H⋯O hydrogen bonds are found in the crystal structure.

Related literature

For our past work based on the 2-propyl-1H-imidazole-4,5-carboxyl­ate (H3pimda) ligand, see: Yan et al. (2010[Yan, J.-B., Li, S.-J., Song, W.-D., Wang, H. & Miao, D.-L. (2010). Acta Cryst. E66, m99.]); Li et al. (2010[Li, S.-J., Yan, J.-B., Song, W.-D., Wang, H. & Miao, D.-L. (2010). Acta Cryst. E66, m280.]); Song et al. (2010[Song, W.-D., Yan, J.-B., Li, S.-J., Miao, D.-L. & Li, X.-F. (2010). Acta Cryst. E66, m53.]); He et al. (2010[He, L.-Z., Li, S.-J., Song, W.-D. & Miao, D.-L. (2010). Acta Cryst. E66, m896.]); Fan et al. (2010[Fan, R.-Z., Li, S.-J., Song, W.-D., Miao, D.-L. & Hu, S.-W. (2010). Acta Cryst. E66, m897-m898.]). For related coordination polymers based on H3EIDC (2-ethyl-1H-imidazole-4,5-dicarboxyl­ate), see: Wang et al. (2008[Wang, S., Zhang, L. R., Li, G. H., Huo, Q. S. & Liu, Y. L. (2008). CrystEngComm 10, 1662-1666.]); Zhang et al. (2010[Zhang, F. W., Li, Z. F., Ge, T. Z., Yao, H. C., Li, G., Lu, H. J. & Zhu, Y. Y. (2010). Inorg. Chem. 49, 3776-3788.]); Li et al. (2011[Li, S.-J., Ma, X.-T., Song, W.-D., Li, X.-F. & Liu, J.-H. (2011). Acta Cryst. E67, m295-m296.]). For the synthesis of H3EIDC, see: Sun et al. (2006[Sun, T., Ma, J.-P., Huang, R.-Q. & Dong, Y.-B. (2006). Acta Cryst. E62, o2751-o2752.]).

[Scheme 1]

Experimental

Crystal data

  • C7H10N2O5

  • Mr = 202.17

  • Monoclinic, P 21 /c

  • a = 7.6132 (6) Å

  • b = 14.3779 (16) Å

  • c = 7.9396 (8) Å

  • β = 97.799 (1)°

  • V = 861.04 (15) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.13 mm−1

  • T = 298 K

  • 0.50 × 0.41 × 0.40 mm
Data collection

  • Bruker SMART 1000 CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2007[Bruker (2007). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.936, Tmax = 0.948

  • 4224 measured reflections

  • 1510 independent reflections

  • 1166 reflections with I > 2σ(I)

  • Rint = 0.031
Refinement

  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.106

  • S = 1.05

  • 1510 reflections

  • 129 parameters

  • 3 restraints

  • H-atom parameters constrained

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1⋯O4i 0.86 1.91 2.754 (2) 168
N2—H2⋯O1Wii 0.86 1.89 2.751 (2) 177
O2—H2A⋯O3 0.82 1.63 2.452 (2) 176
O1W—H1W⋯O2iii 0.85 2.05 2.8863 (19) 169
O1W—H2W⋯O1 0.85 2.03 2.849 (2) 163
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iii) -x+2, -y+1, -z.

Data collection: SMART (Bruker, 2007[Bruker (2007). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). SMART, SAINT and SADABS. 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, 1R. DOI: 10.1107/S1600536811010774/jh2272sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811010774/jh2272Isup2.hkl

checkCIF report


Comment top

4,5-imidazoledicarboxylic acid (H3IDC) ligand posesses great potential for coordination interactions and hydrogen bonding, can be deprotonated to generate H2IDC-, HIDC2- and IDC3- anions at different pH values. Up to date, it has been widely studied. 2-propyl-1H-imidazole-4,5-carboxylate (H3pimda) ligand as one derivative of H3IDC with efficient N,O-donors has been used to obtain new metal-organic complexes by our research group(Song et al., 2010; Yan et al., 2010; He et al. 2010; Fan et al. 2010; Li et al. 2010). Recently, an analogue of H3IDC, 2-ethyl-1H-imidazole-4,5-dicarboxylate (H3EIDC)ligand has also been used to construct intriguing coordination polymers (Wang et al., 2008; Zhang et al. , 2010; Li et al., 2011;). However, the crystal structure of H3EIDC ligand has not been determined. Considering that in mind, we focus on obtaining the crystal and its crystal structure will be reported here.

As illustrated in Fig. 1, the title compound, (C7H8N2O4).H2O, crystallizes as a zwitterion in which the imidazole N atom is protonated, one of the carboxylate groups is deprontonated. The two carboxyl groups are approximately coplanar with the imidazole ring, as indicated by the fact that the O1—C1—C2—C3 and O2—C1—C2—C3 torsion angles are -176.8 (2) ° and 2.9 (4) °, respectively; the O3—C4—C3—C2 and O4—C4—C3—C2 torsion angles are -4.6 (3) ° and 176.4 (2) °, respectively. The solvent water molecules are linked to the organic ligands via N—H···O and O—H···O hydrogen bonds(Table 1), which stabilize the three-dimensional network(Fig. 2).

Related literature top

For our past work based on the 2-propyl-1H-imidazole-4,5-carboxylate (H3pimda) ligand, see: Yan et al. (2010); Li et al. (2010); Song et al. (2010); He et al. (2010); Fan et al. (2010). For related coordination polymers based on H3EIDC (2-ethyl-1H-imidazole-4,5-dicarboxylate), see: Wang et al. (2008); Zhang et al. (2010); Li et al. (2011). For the synthesis of H3EIDC, see: Sun et al. (2006).

Experimental top

The organic molecule powder was abtained from 2-ethylbenzimidazole according to a literature procedure (Sun et al. 2006), then the 2-ethyl-1H-imidazole-4,5-dicarboxylate(0.5 mmol, 0.9 g) was disolved in 15 ml of H2O solution with the pH of 6 adjusted by NaOH, colorless crystals was obtained by slow evaporation of the solvent at room temperature.

Refinement top

H atoms of the water molecule were located in a difference Fourier map and refined as riding with an O—H distance restraint of 0.84 (1) Å, with Uiso(H) = 1.5 Ueq. The H···H distances within the water molecules were restraint to 1.39 (1) Å. Carboxyl H atoms were located in a difference map but were refined as riding on the parent O atoms with with O—H = 0.82 Å with Uiso(H) = 1.5 Ueq(O). Carbon and nitrogen bound H atoms were placed at calculated positions and were treated as riding on the parent C or N atoms with C—H = 0.96 (methyl), 0.97 (methylene) and N—H = 0.86 Å, Uiso(H) = 1.2 or 1.5 Ueq(C, N).

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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
[Figure 1] Fig. 1. The structure of the title compound, showing the atomic numbering scheme. Non-H atoms are shown with 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. A view of the three-dimensional network constructed by O—H···O and N—H···O hydrogen bonding interactions
2-Ethyl-1H-imidazole-4-carboxylate monohydrate top
Crystal data top
C7H10N2O5F(000) = 424
Mr = 202.17Dx = 1.560 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1702 reflections
a = 7.6132 (6) Åθ = 2.5–25.9°
b = 14.3779 (16) ŵ = 0.13 mm−1
c = 7.9396 (8) ÅT = 298 K
β = 97.799 (1)°Block, colorless
V = 861.04 (15) Å30.50 × 0.41 × 0.40 mm
Z = 4
Data collection top
Bruker SMART 1000 CCD area-detector
diffractometer		1510 independent reflections
Radiation source: fine-focus sealed tube1166 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
ϕ and ω scansθmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2007)		h = −9→8
Tmin = 0.936, Tmax = 0.948k = −17→13
4224 measured reflectionsl = −9→7
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.038H-atom parameters constrained
wR(F2) = 0.106 w = 1/[σ2(Fo2) + (0.047P)2 + 0.3916P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max < 0.001
1510 reflectionsΔρmax = 0.28 e Å−3
129 parametersΔρmin = −0.21 e Å−3
3 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.060 (5)
Crystal data top
C7H10N2O5V = 861.04 (15) Å3
Mr = 202.17Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.6132 (6) ŵ = 0.13 mm−1
b = 14.3779 (16) ÅT = 298 K
c = 7.9396 (8) Å0.50 × 0.41 × 0.40 mm
β = 97.799 (1)°
Data collection top
Bruker SMART 1000 CCD area-detector
diffractometer		1510 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2007)		1166 reflections with I > 2σ(I)
Tmin = 0.936, Tmax = 0.948Rint = 0.031
4224 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0383 restraints
wR(F2) = 0.106H-atom parameters constrained
S = 1.05Δρmax = 0.28 e Å−3
1510 reflectionsΔρmin = −0.21 e Å−3
129 parameters
Special details top

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 > 2sigma(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
N10.4705 (2)0.42162 (11)0.2301 (2)0.0314 (4)
H10.48600.48050.22080.038*
N20.3607 (2)0.29056 (11)0.2927 (2)0.0305 (4)
H20.29320.24990.33080.037*
O10.7740 (2)0.46097 (10)0.0811 (2)0.0517 (5)
O20.8238 (2)0.31103 (10)0.0434 (2)0.0457 (5)
H2A0.77700.26190.06530.069*
O30.6974 (2)0.16119 (9)0.1124 (2)0.0433 (4)
O40.4800 (2)0.11124 (9)0.2502 (2)0.0436 (4)
O1W0.8455 (2)0.65550 (10)0.0862 (2)0.0501 (5)
H1W0.94760.65820.05430.075*
H2W0.81890.59950.10570.075*
C10.7364 (3)0.37964 (14)0.0950 (3)0.0356 (5)
C20.5789 (3)0.35434 (13)0.1777 (2)0.0295 (5)
C30.5090 (3)0.27125 (13)0.2173 (2)0.0282 (5)
C40.5648 (3)0.17372 (13)0.1935 (3)0.0314 (5)
C50.3383 (3)0.38238 (13)0.2972 (3)0.0310 (5)
C60.1908 (3)0.43371 (15)0.3579 (3)0.0466 (6)
H6A0.12120.46320.26100.056*
H6B0.24030.48270.43400.056*
C70.0694 (3)0.37559 (17)0.4485 (3)0.0528 (7)
H7A0.02210.32570.37580.079*
H7B−0.02590.41350.47730.079*
H7C0.13450.35040.55030.079*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0332 (9)0.0177 (8)0.0455 (11)0.0005 (7)0.0140 (8)0.0015 (7)
N20.0316 (9)0.0200 (8)0.0425 (10)−0.0005 (6)0.0145 (8)0.0011 (7)
O10.0503 (10)0.0288 (9)0.0821 (13)−0.0062 (7)0.0310 (9)0.0027 (8)
O20.0437 (9)0.0295 (8)0.0707 (11)0.0011 (7)0.0321 (8)0.0009 (7)
O30.0479 (9)0.0275 (8)0.0601 (10)0.0068 (6)0.0272 (8)−0.0009 (7)
O40.0460 (9)0.0202 (7)0.0690 (11)0.0006 (6)0.0236 (8)0.0029 (7)
O1W0.0479 (10)0.0283 (8)0.0813 (12)−0.0006 (7)0.0344 (9)−0.0023 (8)
C10.0344 (11)0.0281 (11)0.0466 (13)0.0005 (9)0.0137 (10)0.0017 (9)
C20.0306 (11)0.0234 (10)0.0355 (11)0.0029 (8)0.0087 (9)−0.0001 (8)
C30.0296 (10)0.0222 (10)0.0340 (11)0.0015 (8)0.0090 (9)−0.0005 (8)
C40.0337 (11)0.0227 (10)0.0389 (12)0.0023 (8)0.0092 (9)−0.0002 (9)
C50.0313 (11)0.0222 (10)0.0414 (12)0.0011 (8)0.0124 (9)0.0005 (9)
C60.0433 (13)0.0273 (12)0.0751 (17)0.0048 (9)0.0295 (13)−0.0017 (11)
C70.0468 (14)0.0451 (14)0.0734 (17)0.0080 (11)0.0334 (13)0.0037 (13)
Geometric parameters (Å, º) top
N1—C51.327 (2)O1W—H2W0.8501
N1—C21.372 (2)C1—C21.488 (3)
N1—H10.8600C2—C31.362 (3)
N2—C51.332 (3)C3—C41.485 (3)
N2—C31.376 (2)C5—C61.478 (3)
N2—H20.8600C6—C71.500 (3)
O1—C11.212 (2)C6—H6A0.9700
O2—C11.288 (2)C6—H6B0.9700
O2—H2A0.8200C7—H7A0.9600
O3—C41.281 (2)C7—H7B0.9600
O4—C41.227 (2)C7—H7C0.9600
O1W—H1W0.8500
C5—N1—C2110.02 (16)O4—C4—C3118.07 (17)
C5—N1—H1125.0O3—C4—C3117.11 (17)
C2—N1—H1125.0N1—C5—N2107.67 (16)
C5—N2—C3109.11 (15)N1—C5—C6124.74 (17)
C5—N2—H2125.4N2—C5—C6127.55 (17)
C3—N2—H2125.4C5—C6—C7115.01 (18)
C1—O2—H2A109.5C5—C6—H6A108.5
H1W—O1W—H2W110.3C7—C6—H6A108.5
O1—C1—O2124.86 (19)C5—C6—H6B108.5
O1—C1—C2119.35 (18)C7—C6—H6B108.5
O2—C1—C2115.80 (17)H6A—C6—H6B107.5
C3—C2—N1106.15 (16)C6—C7—H7A109.5
C3—C2—C1132.84 (18)C6—C7—H7B109.5
N1—C2—C1121.01 (17)H7A—C7—H7B109.5
C2—C3—N2107.05 (16)C6—C7—H7C109.5
C2—C3—C4132.14 (17)H7A—C7—H7C109.5
N2—C3—C4120.81 (17)H7B—C7—H7C109.5
O4—C4—O3124.82 (17)
C5—N1—C2—C3−0.7 (2)C5—N2—C3—C4−179.30 (18)
C5—N1—C2—C1179.02 (18)C2—C3—C4—O4176.4 (2)
O1—C1—C2—C3−176.8 (2)N2—C3—C4—O4−3.4 (3)
O2—C1—C2—C32.9 (4)C2—C3—C4—O3−4.6 (3)
O1—C1—C2—N13.5 (3)N2—C3—C4—O3175.56 (18)
O2—C1—C2—N1−176.74 (19)C2—N1—C5—N21.3 (2)
N1—C2—C3—N2−0.1 (2)C2—N1—C5—C6−176.3 (2)
C1—C2—C3—N2−179.8 (2)C3—N2—C5—N1−1.3 (2)
N1—C2—C3—C4−179.9 (2)C3—N2—C5—C6176.2 (2)
C1—C2—C3—C40.4 (4)N1—C5—C6—C7−172.7 (2)
C5—N2—C3—C20.9 (2)N2—C5—C6—C710.2 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O4i0.861.912.754 (2)168
N2—H2···O1Wii0.861.892.751 (2)177
O2—H2A···O30.821.632.452 (2)176
O1W—H1W···O2iii0.852.052.8863 (19)169
O1W—H2W···O10.852.032.849 (2)163
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) −x+2, −y+1, −z.

Experimental details

Crystal data
Chemical formulaC7H10N2O5
Mr202.17
Crystal system, space groupMonoclinic, P21/c
Temperature (K)298
a, b, c (Å)7.6132 (6), 14.3779 (16), 7.9396 (8)
β (°) 97.799 (1)
V (Å3)861.04 (15)
Z4
Radiation typeMo Kα
µ (mm−1)0.13
Crystal size (mm)0.50 × 0.41 × 0.40
Data collection
DiffractometerBruker SMART 1000 CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2007)
Tmin, Tmax0.936, 0.948
No. of measured, independent and
observed [I > 2σ(I)] reflections		4224, 1510, 1166
Rint0.031
(sin θ/λ)max (Å−1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.106, 1.05
No. of reflections1510
No. of parameters129
No. of restraints3
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.28, −0.21

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O4i0.861.912.754 (2)168
N2—H2···O1Wii0.861.892.751 (2)177
O2—H2A···O30.821.632.452 (2)176
O1W—H1W···O2iii0.852.052.8863 (19)169
O1W—H2W···O10.852.032.849 (2)163
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) −x+2, −y+1, −z.
 

Acknowledgements

The work was supported by the Nonprofit Industry Foundation of the National Ocean Administration of China (grant No. 2000905021), the Guangdong Ocean Fisheries Technology Promotion Project [grant No. A2009003–018(c)], the Guangdong Chinese Academy of Science Comprehensive Strategic Cooperation Project (grant No. 2009B091300121), the Guangdong Province Key Project in the Field of Social Development [grant No. A2009011–007(c)], the Science and Technology Department of Guangdong Province Project (grant No. 00087 061110314018) and the Guangdong Natural Science Foundation (No. 9252408801000002).

References

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ISSN: 2056-9890
Volume 67| Part 4| April 2011| Pages o996-o997
doi:10.1107/S1600536811010774
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