research communications
H-imidazol-3-ium hydrogen oxalate dihydrate
of 2-methyl-1aLaboratoire de Chimie Minérale et Analytique (LACHIMIA), Département de Chimie, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal, and bICMUB UMR 6302, Université de Bourgogne, Faculté des Sciences, 9 avenue Alain Savary, 21000 Dijon, France
*Correspondence e-mail: mouhamadoubdiop@gmail.com, hcattey@u-bourgogne.fr
Single crystals of the title molecular salt, C4H7N2+·HC2O4−·2H2O, were isolated from the reaction of 2-methyl-1H-imidazole and oxalic acid in a 1:1 molar ratio in water. In the crystal, the cations and anions are positioned alternately along an infinite [010] ribbon and linked together through bifurcated N—H⋯(O,O) hydrogen bonds. The water molecules of crystallization link the chains into (10-1) bilayers, with the methyl groups of the cations organized in an isotactic manner.
Keywords: crystal structure; organic salt; monosubstituted imidazolium; hydrogen oxalate; hydrogen bonds.
CCDC reference: 1491387
1. Chemical context
Imidazolium-type building blocks are useful in the field of crystal engineering (MacDonald et al., 2001). With many possibilities of substitution (involving various positions around the five-membered ring) and via the propagation of multidirectional hydrogen-bonding interactions, they easily lead to the self-assembly of poly-dimensional packing networks. In 2010, Callear and co-workers described various topologies based on imidazolium/dicarboxylic acid combinations and showed the crystal-packing effects of substitution in the imidazole ring (Callear et al., 2010). In this context, and for some time, our group has focused on the contribution of the 2-methylimidazolium cation as a in organic (Diop, Diop & Maris, 2016) and organic–inorganic hybrid salts (Diop, Diop & Maris, 2015; Diop, Diop, Plasseraud & Maris, 2015, 2016). Continuing our ongoing studies in this field, we report herein the of a new hydrated organic salt, namely 2-methyl-1H-imidazol-3-ium hydrogen oxalate dihydrate, (I), isolated by reacting 2-methyl-1H-imidazole and oxalic acid in a 1:1 molar ratio in water.
2. Structural comments
The consists of four components, i.e. one 2-methyl-1H-imidazol-3-ium cation, one hydrogen oxalate anion and two solvent water molecules (Fig. 1). The hydrogen oxalate anion is slightly twisted, with O1—C6—C5—O3 and O2—C6—C5—O4 torsion angles of 6.9 (3) and 7.3 (3)°, respectively. The C5—O3 and C5—O4 bonds are almost equal in length [1.249 (2) and 1.245 (2) Å, respectively], whereas C6—O2 is typical for a >C=O group [1.206 (2) Å] and C6—O1 has a normal C—OH bond length [1.306 (2) Å] (Adams, 1978).
of the title molecular salt (I)3. Supramolecular features
Hydrogen-bonding interactions are listed in Table 1 and illustrated in Fig. 2. Both N—H groups of the imidazolium cation are involved in asymmetric bifurcated N—H⋯(O,O) hydrogen bonds with two distinct neighbouring hydrogen oxalate anions, which initiates the propagation of an infinite ribbon along the b-axis direction. Considering the orientation of the methyl groups of the cations along the ribbon, the sequence can be described as `isotactic'. The cations and anions are positioned alternately and are almost coplanar [dihedral angle between adjacent species = 1.15 (9)°].
As well as the cation-to-anion links, the OH group of the anion acts as a hydrogen-bond donor with one molecule of water, which is also the donor for hydrogen-bond interactions with (i) a second molecule of water and (ii) an O atom of a hydrogen oxalate anion involved in a neighbouring ribbon. The second water molecule also bridges two distinct hydrogen oxalate anions through two O—H⋯O hydrogen bonds. Thus, all the O atoms of the hydrogen oxalate anions are involved in the hydrogen-bonding network.
The supramolecular arrangement depicted in Fig. 2 relies on the contributions of the four components of (I) and can be described as resulting from three levels of organization: (i) C4H7N2+ and HC2O4− assembled in infinite ribbons; (ii) parallel ribbons of C4H7N2+/HC2O4− connected together by water molecules, which leads to a staircase–sheet structure; (iii) sheets stacked in pairs which can be described as a two-dimensional bilayer-like arrangement propagating in (10). This final organization is again induced by the formation of hydrogen-bonding interactions between the water molecules contained in each sheet. The inter-sheet distance is about 3.4 Å. Interestingly, all the methyl substituents of the imidazolium rings are oriented in the same direction along the c axis. Thus, the isotacticity observed at the ribbon level is also extended across the supramolecular network.
4. Database survey
To date, 176 structures of hydrogen oxalates have been deposited in the Cambridge Structural Database (CSD; Groom et al., 2016). Among these, five hits describe imidazolium salts or derivatives, i.e. imidazolium hydrogen oxalate [CSD refcodes MEQPAZ (MacDonald et al., 2001) and MEQPAZ01 (Prasad et al., 2002)], (S)-(+)-2-[2-(biphenyl-2-yl)-1-methylethyl]-4,5-dihydro-1H-imidazolium hydrogen oxalate (GAQTOI; Giannella et al., 2005), 1,3-diisopropyl-4,5-dimethylimidazolium hydrogen oxalate (DOHTOK; Abu-Rayyan et al., 2008), (S)-(−)-6-(4-bromophenyl)-2,3,5,6-tetrahydrothiazolo[2,3-b]imidazolium hydrogen oxalate (ROFQAF; Minor & Chruszcz, 2008).
5. Synthesis and crystallization
Equimolar solutions of 2-methyl-1H-imidazole (6.51 g, 79.39 mmol) and H2C2O4·2H2O (10.00 g, 79.39 mmol) in water (100 ml) were mixed together at room temperature (301 K). Needle-shaped colourless crystals of (I) were obtained after one week by evaporation of the solvent at 333 K (yield 10.83 g, 65.5%).
6. Refinement
Crystal data, data collection and structure . All H atoms on C, O and N atoms were placed at calculated positions using a riding model, with aromatic C—H = 0.95 Å and aromatic N—H = 0.88 Å, and with Uiso(H) = 1.2Ueq(C,N), or hydroxy O—H = 0.84 Å, water O—H = 0.85 Å and methyl C—H = 0.98 Å, and with Uiso(H) = 1.5Ueq(O,C).
details are summarized in Table 2
|
Supporting information
CCDC reference: 1491387
https://doi.org/10.1107/S2056989016011038/hb7595sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016011038/hb7595Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989016011038/hb7595Isup3.cml
Data collection: APEX2 (Bruker, 2014); cell
SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).C4H7N2+·C2HO4−·2H2O | F(000) = 440 |
Mr = 208.18 | Dx = 1.451 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 6.7139 (7) Å | Cell parameters from 2578 reflections |
b = 9.5116 (7) Å | θ = 3.5–26.4° |
c = 15.2115 (13) Å | µ = 0.13 mm−1 |
β = 101.151 (6)° | T = 115 K |
V = 953.07 (15) Å3 | Needle, colourless |
Z = 4 | 0.30 × 0.10 × 0.08 mm |
Bruker APEXII CCD diffractometer | 2187 independent reflections |
Radiation source: X-ray tube, Siemens KFF Mo 2K-90C | 1258 reflections with I > 2σ(I) |
TRIUMPH curved crystal monochromator | Rint = 0.063 |
Detector resolution: 1024 x 1024 pixels mm-1 | θmax = 27.5°, θmin = 2.5° |
φ and ω scans' | h = −8→8 |
Absorption correction: multi-scan SADABS (Bruker, 2014) was used for absorption correction. wR2(int) was 0.0622 before and 0.0548 after correction. The Ratio of minimum to maximum transmission is 0.9269. The λ/2 correction factor is 0.00150. | k = −12→12 |
Tmin = 0.691, Tmax = 0.746 | l = −19→19 |
15445 measured reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.043 | H-atom parameters constrained |
wR(F2) = 0.115 | w = 1/[σ2(Fo2) + (0.0448P)2 + 0.3824P] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max < 0.001 |
2187 reflections | Δρmax = 0.40 e Å−3 |
135 parameters | Δρmin = −0.23 e Å−3 |
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. |
x | y | z | Uiso*/Ueq | ||
O4 | 0.3344 (2) | 0.84241 (13) | 0.62704 (8) | 0.0224 (3) | |
O3 | 0.3377 (2) | 0.60714 (13) | 0.62300 (9) | 0.0247 (3) | |
O1 | 0.1928 (2) | 0.60978 (13) | 0.44891 (9) | 0.0254 (4) | |
H1A | 0.1572 | 0.6196 | 0.3932 | 0.038* | |
O6 | 0.3979 (2) | 0.45757 (14) | 0.22494 (10) | 0.0314 (4) | |
H6A | 0.3724 | 0.3954 | 0.1842 | 0.047* | |
H6B | 0.4883 | 0.4270 | 0.2677 | 0.047* | |
O2 | 0.2253 (2) | 0.84212 (14) | 0.44546 (9) | 0.0311 (4) | |
O5 | 0.1121 (3) | 0.61142 (17) | 0.27986 (9) | 0.0357 (4) | |
H5A | 0.1986 | 0.5615 | 0.2599 | 0.054* | |
H5B | 0.0183 | 0.6360 | 0.2367 | 0.054* | |
N2 | 0.2719 (2) | 0.11229 (16) | 0.54620 (11) | 0.0231 (4) | |
H2 | 0.2824 | 0.0244 | 0.5647 | 0.028* | |
N1 | 0.2803 (2) | 0.33729 (17) | 0.54697 (11) | 0.0245 (4) | |
H1 | 0.2970 | 0.4248 | 0.5657 | 0.029* | |
C5 | 0.3089 (3) | 0.7264 (2) | 0.58854 (12) | 0.0186 (4) | |
C6 | 0.2361 (3) | 0.7327 (2) | 0.48607 (12) | 0.0187 (4) | |
C1 | 0.3139 (3) | 0.2239 (2) | 0.59833 (14) | 0.0244 (5) | |
C2 | 0.2138 (3) | 0.2951 (2) | 0.45809 (14) | 0.0287 (5) | |
H2A | 0.1789 | 0.3549 | 0.4074 | 0.034* | |
C4 | 0.3880 (3) | 0.2233 (2) | 0.69571 (13) | 0.0291 (5) | |
H4A | 0.3300 | 0.1428 | 0.7222 | 0.044* | |
H4B | 0.3472 | 0.3106 | 0.7215 | 0.044* | |
H4C | 0.5364 | 0.2160 | 0.7085 | 0.044* | |
C3 | 0.2088 (3) | 0.1547 (2) | 0.45810 (14) | 0.0296 (5) | |
H3 | 0.1696 | 0.0954 | 0.4075 | 0.036* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O4 | 0.0311 (8) | 0.0146 (7) | 0.0198 (7) | −0.0010 (6) | 0.0005 (6) | −0.0023 (6) |
O3 | 0.0375 (9) | 0.0141 (7) | 0.0196 (7) | 0.0018 (6) | −0.0018 (6) | 0.0018 (6) |
O1 | 0.0417 (10) | 0.0159 (7) | 0.0160 (7) | −0.0014 (6) | −0.0010 (7) | −0.0013 (5) |
O6 | 0.0439 (11) | 0.0223 (8) | 0.0224 (8) | 0.0083 (7) | −0.0075 (7) | −0.0045 (6) |
O2 | 0.0568 (11) | 0.0135 (7) | 0.0203 (8) | −0.0004 (7) | 0.0009 (7) | 0.0024 (6) |
O5 | 0.0412 (11) | 0.0421 (10) | 0.0201 (8) | 0.0125 (8) | −0.0030 (7) | −0.0046 (7) |
N2 | 0.0282 (10) | 0.0116 (8) | 0.0285 (10) | −0.0004 (7) | 0.0026 (8) | 0.0012 (7) |
N1 | 0.0280 (10) | 0.0128 (8) | 0.0322 (10) | 0.0004 (7) | 0.0043 (8) | −0.0006 (7) |
C5 | 0.0192 (11) | 0.0153 (9) | 0.0200 (10) | 0.0020 (8) | 0.0010 (8) | 0.0006 (8) |
C6 | 0.0198 (10) | 0.0145 (9) | 0.0209 (10) | 0.0008 (8) | 0.0016 (8) | −0.0011 (8) |
C1 | 0.0218 (11) | 0.0178 (9) | 0.0332 (12) | 0.0000 (9) | 0.0047 (9) | −0.0005 (9) |
C2 | 0.0363 (13) | 0.0221 (11) | 0.0265 (11) | 0.0009 (10) | 0.0029 (10) | 0.0007 (9) |
C4 | 0.0348 (13) | 0.0238 (10) | 0.0282 (11) | −0.0002 (10) | 0.0053 (10) | −0.0016 (9) |
C3 | 0.0395 (14) | 0.0205 (11) | 0.0276 (12) | −0.0001 (10) | 0.0033 (10) | −0.0028 (9) |
O4—C5 | 1.245 (2) | N1—H1 | 0.8800 |
O3—C5 | 1.249 (2) | N1—C1 | 1.325 (3) |
O1—H1A | 0.8400 | N1—C2 | 1.398 (2) |
O1—C6 | 1.306 (2) | C5—C6 | 1.542 (3) |
O6—H6A | 0.8499 | C1—C4 | 1.469 (3) |
O6—H6B | 0.8501 | C2—H2A | 0.9500 |
O2—C6 | 1.206 (2) | C2—C3 | 1.336 (3) |
O5—H5A | 0.8500 | C4—H4A | 0.9800 |
O5—H5B | 0.8500 | C4—H4B | 0.9800 |
N2—H2 | 0.8800 | C4—H4C | 0.9800 |
N2—C1 | 1.323 (2) | C3—H3 | 0.9500 |
N2—C3 | 1.385 (2) | ||
C6—O1—H1A | 109.5 | N2—C1—N1 | 107.91 (17) |
H6A—O6—H6B | 109.5 | N2—C1—C4 | 126.36 (18) |
H5A—O5—H5B | 109.5 | N1—C1—C4 | 125.72 (18) |
C1—N2—H2 | 125.2 | N1—C2—H2A | 126.6 |
C1—N2—C3 | 109.64 (16) | C3—C2—N1 | 106.85 (18) |
C3—N2—H2 | 125.2 | C3—C2—H2A | 126.6 |
C1—N1—H1 | 125.6 | C1—C4—H4A | 109.5 |
C1—N1—C2 | 108.83 (16) | C1—C4—H4B | 109.5 |
C2—N1—H1 | 125.6 | C1—C4—H4C | 109.5 |
O4—C5—O3 | 127.68 (17) | H4A—C4—H4B | 109.5 |
O4—C5—C6 | 115.41 (16) | H4A—C4—H4C | 109.5 |
O3—C5—C6 | 116.90 (17) | H4B—C4—H4C | 109.5 |
O1—C6—C5 | 113.79 (16) | N2—C3—H3 | 126.6 |
O2—C6—O1 | 124.38 (17) | C2—C3—N2 | 106.76 (18) |
O2—C6—C5 | 121.81 (18) | C2—C3—H3 | 126.6 |
O4—C5—C6—O1 | −173.95 (17) | C1—N1—C2—C3 | 0.0 (2) |
O4—C5—C6—O2 | 7.3 (3) | C2—N1—C1—N2 | 0.0 (2) |
O3—C5—C6—O1 | 6.9 (3) | C2—N1—C1—C4 | 179.0 (2) |
O3—C5—C6—O2 | −171.78 (19) | C3—N2—C1—N1 | 0.0 (2) |
N1—C2—C3—N2 | 0.0 (2) | C3—N2—C1—C4 | −179.1 (2) |
C1—N2—C3—C2 | 0.0 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3 | 0.88 | 1.94 | 2.811 (2) | 172 |
N1—H1···O1 | 0.88 | 2.50 | 2.991 (2) | 116 |
N2—H2···O4i | 0.88 | 1.97 | 2.842 (2) | 169 |
N2—H2···O2i | 0.88 | 2.49 | 2.977 (2) | 116 |
O1—H1A···O5 | 0.84 | 1.69 | 2.5234 (19) | 169 |
O6—H6A···O2ii | 0.85 | 2.02 | 2.7893 (19) | 150 |
O6—H6B···O3iii | 0.85 | 1.87 | 2.700 (2) | 166 |
O5—H5A···O6 | 0.85 | 1.82 | 2.672 (2) | 176 |
O5—H5B···O4iv | 0.85 | 1.88 | 2.720 (2) | 167 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1/2, y−1/2, −z+1/2; (iii) −x+1, −y+1, −z+1; (iv) x−1/2, −y+3/2, z−1/2. |
Acknowledgements
The authors gratefully acknowledge the Cheikh Anta Diop University of Dakar (Senegal), the Centre National de la Recherche Scientifique (CNRS, France) and the University of Burgundy (Dijon, France).
References
Abu-Rayyan, A., Abu-Salem, Q., Kuhn, N., Maichle-Mossmer, C., Mallah, E. & Steimann, M. (2008). Z. Naturforsch. Teil B, 63, 1015–1019. CAS Google Scholar
Adams, J. M. (1978). Acta Cryst. B34, 1218–1220. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Bruker (2013). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Callear, S. K., Hursthouse, M. B. & Threlfall, T. L. (2010). CrystEngComm, 12, 898–908. Web of Science CSD CrossRef CAS Google Scholar
Diop, M. B., Diop, L. & Maris, T. (2015). Acta Cryst. E71, 1064–1066. Web of Science CSD CrossRef IUCr Journals Google Scholar
Diop, M. B., Diop, L. & Maris, T. (2016). Acta Cryst. E72, 482–485. Web of Science CSD CrossRef IUCr Journals Google Scholar
Diop, M. B., Diop, L., Plasseraud, L. & Maris, T. (2015). Acta Cryst. E71, 520–522. Web of Science CSD CrossRef IUCr Journals Google Scholar
Diop, M. B., Diop, L., Plasseraud, L. & Maris, T. (2016). Acta Cryst. E72, 355–357. Web of Science CSD CrossRef IUCr Journals Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Giannella, M., Gentili, F., Bruni, B., Messori, L. & Di Vaira, M. (2005). Acta Cryst. E61, o2376–o2378. Web of Science CSD CrossRef IUCr Journals Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CSD CrossRef IUCr Journals Google Scholar
MacDonald, J. C., Dorrestein, P. C. & Pilley, M. M. (2001). Cryst. Growth Des. 1, 29–38. Web of Science CSD CrossRef CAS Google Scholar
Minor, T. & Chruszcz, M. (2008). Acta Cryst. E64, o1954. Web of Science CSD CrossRef IUCr Journals Google Scholar
Prasad, R. A., Neeraj, S., Vaidhyanathan, R. & Natarajan, S. (2002). J. Solid State Chem. 166, 128–141. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.