organic compounds
1H-Imidazol-3-ium-4-carboxylate
aCollege of Chemistry and Life Science, Weinan Normal University, 714000 Weinan, Shaanxi, People's Republic of China, bChemistry and Chemical Engineering College, Yantai University, 264005 Yantai, Shandong, People's Republic of China, cEngineering Company Limited of China Railway and Airport Group, 714000 Weinan, Shaanxi, People's Republic of China, and dShaanxi Railway Institute, 714000 Weinan, Shaanxi, People's Republic of China
*Correspondence e-mail: ytsxzl@126.com
In the title compound, C4H4N2O2, both imidazole N atoms are protonated and carboxylate group is deprotonated, resulting in a zwitterion. The molecule is essentially planar, with an r.m.s. deviation of 0.012 (1) Å. In the crystal, N—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.674 (2) Å] between the imidazole rings link the molecules into a three-dimensional supramolecular network.
Related literature
For general background to the construction of coordination polymers based on 1H-imidazole-4,5-dicarboxylic acid, see: Alkordi, Liu et al. (2008); Alkordi, Brant et al. (2009); Gu et al. (2010); Lu et al. (2006); Nouar et al. (2009); Wang et al. (2010). For related complexes with 1H-imidazole-4-carboxylic acid, see: Haggag (2005); Starosta & Leciejewicz (2006); Gryz et al. (2007); Yin et al. (2009); Shuai et al. (2011); Zheng et al. (2011). For the synthesis of 1H-imidazole-4-carboxylic acid, see: Davis et al. (1982).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; 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.
Supporting information
10.1107/S1600536811052998/ld2040sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811052998/ld2040Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536811052998/ld2040Isup3.cml
The compound was synthesized from 1H-imidazole-4,5-dicarboxylic acid according to the method reported in the literature (Davis et al., 1982). Colourless single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in water at room temperature.
All non-hydrogen atoms were assigned anisotropic displacement parameters in the
The zwitter-ionic structure was established from a difference Fourier synthesis. Consequently, all hydrogen atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 Å and N—H =0.86 Å and with Uiso(H) =1.2 Ueq(C, N). Since this is a light atom structure (does not contain any atoms heavier than Si) and since the data collection was carried out using Mo radiation, it was not possible to unambiguously determine the of this molecule. In the absence of significant effects Friedel pairs have been merged.Data collection: APEX2 (Bruker, 2008); cell
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: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C4H4N2O2 | F(000) = 232 |
Mr = 112.09 | Dx = 1.657 Mg m−3 |
Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2n | Cell parameters from 1380 reflections |
a = 10.474 (6) Å | θ = 2.6–27.0° |
b = 11.676 (7) Å | µ = 0.14 mm−1 |
c = 3.674 (2) Å | T = 298 K |
V = 449.3 (5) Å3 | Block, colourless |
Z = 4 | 0.25 × 0.21 × 0.18 mm |
Bruker APEXII CCD area-detector diffractometer | 510 independent reflections |
Radiation source: fine-focus sealed tube | 480 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
phi and ω scans | θmax = 26.0°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −12→12 |
Tmin = 0.967, Tmax = 0.976 | k = −14→12 |
2280 measured reflections | l = −4→4 |
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)] = 0.029 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.083 | H-atom parameters constrained |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0578P)2 + 0.0406P] where P = (Fo2 + 2Fc2)/3 |
510 reflections | (Δ/σ)max < 0.001 |
73 parameters | Δρmax = 0.12 e Å−3 |
1 restraint | Δρmin = −0.19 e Å−3 |
C4H4N2O2 | V = 449.3 (5) Å3 |
Mr = 112.09 | Z = 4 |
Orthorhombic, Pna21 | Mo Kα radiation |
a = 10.474 (6) Å | µ = 0.14 mm−1 |
b = 11.676 (7) Å | T = 298 K |
c = 3.674 (2) Å | 0.25 × 0.21 × 0.18 mm |
Bruker APEXII CCD area-detector diffractometer | 510 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 480 reflections with I > 2σ(I) |
Tmin = 0.967, Tmax = 0.976 | Rint = 0.023 |
2280 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 1 restraint |
wR(F2) = 0.083 | H-atom parameters constrained |
S = 1.10 | Δρmax = 0.12 e Å−3 |
510 reflections | Δρmin = −0.19 e Å−3 |
73 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C2 | 0.15183 (19) | 0.33109 (16) | 0.6250 (7) | 0.0265 (5) | |
C1 | 0.20900 (19) | 0.44287 (17) | 0.5153 (6) | 0.0268 (5) | |
N2 | 0.10851 (15) | 0.15065 (14) | 0.7501 (6) | 0.0302 (5) | |
H2 | 0.1149 | 0.0774 | 0.7660 | 0.036* | |
C4 | 0.0113 (2) | 0.21278 (18) | 0.8693 (7) | 0.0301 (5) | |
H4 | −0.0610 | 0.1844 | 0.9853 | 0.036* | |
O2 | 0.31910 (13) | 0.43682 (12) | 0.3734 (5) | 0.0361 (5) | |
O1 | 0.14526 (14) | 0.53104 (13) | 0.5736 (6) | 0.0367 (5) | |
N1 | 0.03417 (16) | 0.32279 (14) | 0.7956 (6) | 0.0284 (5) | |
H1 | −0.0158 | 0.3791 | 0.8456 | 0.034* | |
C3 | 0.1970 (2) | 0.22218 (17) | 0.5977 (7) | 0.0280 (5) | |
H3 | 0.2743 | 0.2003 | 0.4940 | 0.034* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C2 | 0.0254 (9) | 0.0223 (10) | 0.0320 (13) | 0.0003 (8) | −0.0016 (10) | 0.0003 (10) |
C1 | 0.0295 (11) | 0.0190 (9) | 0.0319 (13) | 0.0011 (8) | −0.0047 (9) | 0.0035 (9) |
N2 | 0.0323 (9) | 0.0181 (8) | 0.0401 (11) | −0.0007 (7) | −0.0033 (9) | 0.0011 (9) |
C4 | 0.0275 (10) | 0.0271 (10) | 0.0358 (14) | −0.0035 (8) | −0.0004 (9) | 0.0032 (11) |
O2 | 0.0324 (8) | 0.0235 (7) | 0.0524 (12) | −0.0013 (6) | 0.0078 (8) | 0.0043 (9) |
O1 | 0.0352 (8) | 0.0203 (7) | 0.0545 (12) | 0.0047 (6) | −0.0018 (8) | 0.0025 (9) |
N1 | 0.0279 (9) | 0.0203 (8) | 0.0371 (11) | 0.0024 (7) | −0.0016 (9) | −0.0004 (8) |
C3 | 0.0261 (9) | 0.0222 (10) | 0.0357 (14) | −0.0005 (8) | −0.0022 (10) | 0.0017 (10) |
C2—C3 | 1.361 (3) | N2—C3 | 1.368 (3) |
C2—N1 | 1.386 (3) | N2—H2 | 0.8600 |
C2—C1 | 1.491 (3) | C4—N1 | 1.334 (3) |
C1—O1 | 1.246 (3) | C4—H4 | 0.9300 |
C1—O2 | 1.267 (3) | N1—H1 | 0.8600 |
N2—C4 | 1.324 (3) | C3—H3 | 0.9300 |
C3—C2—N1 | 106.10 (17) | N2—C4—N1 | 108.81 (19) |
C3—C2—C1 | 131.2 (2) | N2—C4—H4 | 125.6 |
N1—C2—C1 | 122.71 (17) | N1—C4—H4 | 125.6 |
O1—C1—O2 | 127.19 (19) | C4—N1—C2 | 108.57 (17) |
O1—C1—C2 | 117.49 (18) | C4—N1—H1 | 125.7 |
O2—C1—C2 | 115.32 (18) | C2—N1—H1 | 125.7 |
C4—N2—C3 | 108.78 (17) | C2—C3—N2 | 107.74 (19) |
C4—N2—H2 | 125.6 | C2—C3—H3 | 126.1 |
C3—N2—H2 | 125.6 | N2—C3—H3 | 126.1 |
C3—C2—C1—O1 | −180.0 (3) | C3—C2—N1—C4 | 0.5 (3) |
N1—C2—C1—O1 | −1.9 (3) | C1—C2—N1—C4 | −178.0 (2) |
C3—C2—C1—O2 | −0.5 (4) | N1—C2—C3—N2 | −0.2 (3) |
N1—C2—C1—O2 | 177.6 (2) | C1—C2—C3—N2 | 178.1 (2) |
C3—N2—C4—N1 | 0.4 (3) | C4—N2—C3—C2 | −0.1 (3) |
N2—C4—N1—C2 | −0.6 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2i | 0.86 | 1.82 | 2.648 (2) | 160 |
N1—H1···O1ii | 0.86 | 1.91 | 2.736 (2) | 161 |
Symmetry codes: (i) −x+1/2, y−1/2, z+1/2; (ii) −x, −y+1, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C4H4N2O2 |
Mr | 112.09 |
Crystal system, space group | Orthorhombic, Pna21 |
Temperature (K) | 298 |
a, b, c (Å) | 10.474 (6), 11.676 (7), 3.674 (2) |
V (Å3) | 449.3 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.14 |
Crystal size (mm) | 0.25 × 0.21 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.967, 0.976 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2280, 510, 480 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.083, 1.10 |
No. of reflections | 510 |
No. of parameters | 73 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.12, −0.19 |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2i | 0.86 | 1.82 | 2.648 (2) | 159.9 |
N1—H1···O1ii | 0.86 | 1.91 | 2.736 (2) | 161.1 |
Symmetry codes: (i) −x+1/2, y−1/2, z+1/2; (ii) −x, −y+1, z+1/2. |
Acknowledgements
The authors gratefully acknowledge the Scientific Research Foundation of Weinan Normal University (grant No. 07YKZ027), the Natural Science Foundation of Yantai University (grant No. HY10Z10), the Science and Technology Research Projects of Yantai City (grant No. 2006GGAO00143), the Science and Technology Research Projects of Shandong Province (grant No. 2008 GG10003020) and the National Science and Technology Research Projects (grant No. 2004BA320B) for supporting this work.
References
Alkordi, M. H., Brant, J. A., Wojtas, L., Kravtsov, V. Ch., Cairns, A. J. & Eddaoudi, M. (2009). J. Am. Chem. Soc. 131, 17753–17755. Web of Science CSD CrossRef PubMed CAS Google Scholar
Alkordi, M. H., Liu, Y. L., Larsen, R. W., Eubank, J. F. & Eddaoudi, M. (2008). J. Am. Chem. Soc. 130, 12639–12641. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2008). APEX2 and SAINT. Bruker AXSInc., Madison, Wisconsin, USA. Google Scholar
Davis, D. P., Kirk, K. L. & Cohen, L. A. (1982). J. Heterocycl. Chem. 19, 253–256. CrossRef CAS Google Scholar
Gryz, M., Starosta, W. & Leciejewicz, J. (2007). J. Coord. Chem. 60, 539–546. Web of Science CSD CrossRef CAS Google Scholar
Gu, Z. G., Cai, Y. P., Fang, H. C., Zhou, Z. Y., Thallapally, P. K., Tian, J., Liu, J. & Exarhos, G. J. (2010). Chem. Commun. 46, 5373–5375. Web of Science CSD CrossRef CAS Google Scholar
Haggag, S. S. (2005). Egypt. J. Chem. 48, 27–41. CAS Google Scholar
Lu, W. G., Su, C. Y., Lu, T. B., Jiang, L. & Chen, J. M. (2006). J. Am. Chem. Soc. 128, 34–35. Web of Science CSD CrossRef PubMed CAS Google Scholar
Nouar, F., Eckert, J., Eubank, J. F., Forster, P. & Eddaoudi, M. (2009). J. Am. Chem. Soc. 131, 2864–2870. Web of Science CSD CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shuai, W., Cai, S. & Zheng, S. (2011). Acta Cryst. E67, m897. Web of Science CSD CrossRef IUCr Journals Google Scholar
Starosta, W. & Leciejewicz, J. (2006). Acta Cryst. E62, m2648–m2650. Web of Science CSD CrossRef IUCr Journals Google Scholar
Wang, S., Zhao, T. T., Li, G. H., Wojtas, L., Huo, Q. S., Eddaoudi, M. & Liu, Y. L. (2010). J. Am. Chem. Soc. 132, 18038–18041. Web of Science CSD CrossRef CAS PubMed Google Scholar
Yin, W. P., Li, Y. G., Mei, X. L. & Yao, J. C. (2009). Chin. J. Struct. Chem. 28, 1155–1159. CAS Google Scholar
Zheng, S., Cai, S., Fan, J. & Zhang, W. (2011). Acta Cryst. E67, m865. Web of Science CSD CrossRef IUCr Journals Google Scholar
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The organic ligands containing N and O donors, especially the N-heterocyclic carboxylates, are ideal candidates for constructing novel metal coordination polymers, because of their versatile coordination modes and potential hydrogen bonding donors and acceptors. Particular attention has been paid to the 1H-imidazole-4,5-dicarboxylic acid ligand (H3IDC), because it can coordinate with metal ions in different coordination fashions to offer a series of complexes with diverse structures and interesting properties (Alkordi, Liu et al., 2008; Alkordi, Brant et al., 2009; Gu et al., 2010; Lu et al., 2006; Nouar et al., 2009; Wang et al., 2010). Recently, an analogue of H3IDC, 1H-imidazole-4-carboxylic acid (H2IMC), has also been used to prepare new coordination polymers (Haggag, 2005; Starosta & Leciejewicz, 2006; Gryz et al., 2007; Yin et al., 2009; Shuai et al., 2011; Zheng et al., 2011). However, the crystal structure of H2IMC ligand has not been determined. With this in mind, we attempteted to obtain its crystal structure that is reported here.
As illustrated in Fig. 1, the title compound, C4H4N2O2, crystallizes as a zwitterion in which the imidazole N atom is protonated and the carboxylate group is deprotonateded. In the crystal structure, intermolecular N2—H2···O2i and N1—H1···O1ii hydrogen bonds (Table 1) [symmetry code: (i) -x + 1/2, y - 1/2, z + 1/2; (ii) -x,-y + 1, z + 1/2] between the imidazole N—H groups and carboxylate O atoms link the molecules into a three-dimensional supramolecular network (Fig. 2). Moreover, the crystal structure is further stabilized by π-π stacking interactions between neighbouring imidazole rings [N2—C4—N1—C2—C3 and N2v—C4v—N1v—C2v—C3v, symmetry code: (v) x, y, z + 1], with centroid···centroid distances of 3.674 (2) Å (Fig. 2).