Acta Cryst. (2009). E65, o115 [ doi:10.1107/S1600536808041706 ]
In the title salt, C7H8N3+·HSO4-, the benzimdazole ring system is planar [mean deviation 0.0086 (1) Å]. In the crystal, N-H
O and O-HO hydrogen-bond interactions give rise to a layer motif.
The treatment of 2-aminobenzimidazole dissolved in methanol with an excess of hydrochloric acid yields the title compound. Single crystal suitable for X-ray diffraction measurement was obtained after 3 days' slow evaporation of the mother liquid at room temperature in air. Anal. Calcd. For C~7~H~9Ñ~3Õ~4~S: C, 36.36; H, 3.92; O, 27.68%. Found: C, 36.17; H, 4.03; N, 27.74%. Main FT—IR absorptions (KBr pellets, cm-1): 3385 (s), 3194 (m), 1687 (s), 1476 (m), 1286 (m), 1206(s), 1175 (vs), 1070 (m), 1026 (m), 888 (s), and 577 (w).
The non-hydrogen atoms were refined anisotropically, whereas the H atoms bonded with carbon, nitrogen and oxygen atoms were placed in geometrically idealized positions (C—H = 0.93 Å, N—H = 0.86 Å and O—H = 0.82 Å) and refined as riding atoms, with Uiso(H) = 1.2Ueq(C) and 1.2U~eq~(N) and Uĩso~(H) = 1.5U~eq~(O).
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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).
![[Figure 1]](./ng2522fig1thm.gif)
| Fig. 1. An ORTEP drawing of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. |
![[Figure 2]](./ng2522fig2thm.gif)
| Fig. 2. A perspective view of the packing structure of the title compound. Symmetry codes: (i) -x + 1, y - 1/2, -z + 1/2; (ii) x, -y + 3/2, z + 1/2. |
| C7H8N3+·HSO4− | F(000) = 480 |
| Mr = 231.23 | Dx = 1.550 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 1841 reflections |
| a = 10.855 (6) Å | θ = 1.0–1.0° |
| b = 13.049 (7) Å | µ = 0.33 mm−1 |
| c = 7.082 (4) Å | T = 291 K |
| β = 99.025 (7)° | Block, colourless |
| V = 990.7 (9) Å3 | 0.16 × 0.12 × 0.10 mm |
| Z = 4 |
| Bruker SMART diffractometer | 1841 independent reflections |
| Radiation source: fine-focus sealed tube | 1408 reflections with I > 2σ(I) |
| graphite | Rint = 0.057 |
| φ and ω scans | θmax = 25.5°, θmin = 2.5° |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −13→13 |
| Tmin = 0.950, Tmax = 0.968 | k = −11→15 |
| 5083 measured reflections | l = −8→8 |
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
| wR(F2) = 0.103 | w = 1/[σ2(Fo2) + (0.0593P)2] where P = (Fo2 + 2Fc2)/3 |
| S = 0.96 | (Δ/σ)max = 0.001 |
| 1841 reflections | Δρmax = 0.23 e Å−3 |
| 136 parameters | Δρmin = −0.35 e Å−3 |
| 0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008) |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0 |
| C7H8N3+·HSO4− | V = 990.7 (9) Å3 |
| Mr = 231.23 | Z = 4 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 10.855 (6) Å | µ = 0.33 mm−1 |
| b = 13.049 (7) Å | T = 291 K |
| c = 7.082 (4) Å | 0.16 × 0.12 × 0.10 mm |
| β = 99.025 (7)° |
| Bruker SMART diffractometer | 1841 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | 1408 reflections with I > 2σ(I) |
| Tmin = 0.950, Tmax = 0.968 | Rint = 0.057 |
| 5083 measured reflections | θmax = 25.5° |
| R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
| wR(F2) = 0.103 | Δρmax = 0.23 e Å−3 |
| S = 0.96 | Δρmin = −0.35 e Å−3 |
| 1841 reflections | Absolute structure: ? |
| 136 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
Experimental. The structure was solved by direct methods (Bruker, 2000) and successive difference Fourier syntheses. |
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 | ||
| C1 | 0.61393 (19) | 0.67017 (16) | 0.3926 (3) | 0.0400 (5) | |
| C2 | 0.80252 (18) | 0.71967 (16) | 0.5357 (3) | 0.0387 (5) | |
| C3 | 0.9247 (2) | 0.72581 (18) | 0.6229 (3) | 0.0483 (6) | |
| H3 | 0.9725 | 0.6674 | 0.6557 | 0.058* | |
| C4 | 0.9730 (2) | 0.82273 (19) | 0.6594 (3) | 0.0533 (6) | |
| H4 | 1.0555 | 0.8296 | 0.7178 | 0.064* | |
| C5 | 0.9026 (2) | 0.91056 (19) | 0.6120 (3) | 0.0563 (6) | |
| H5 | 0.9382 | 0.9746 | 0.6407 | 0.068* | |
| C6 | 0.7787 (2) | 0.90386 (17) | 0.5216 (3) | 0.0497 (6) | |
| H6 | 0.7310 | 0.9620 | 0.4866 | 0.060* | |
| C7 | 0.73133 (18) | 0.80702 (16) | 0.4872 (3) | 0.0385 (5) | |
| N1 | 0.72523 (15) | 0.63593 (13) | 0.4769 (2) | 0.0410 (4) | |
| H1A | 0.7460 | 0.5725 | 0.4925 | 0.049* | |
| N2 | 0.61415 (15) | 0.77282 (13) | 0.3989 (2) | 0.0429 (5) | |
| H2A | 0.5521 | 0.8116 | 0.3555 | 0.051* | |
| N3 | 0.51968 (16) | 0.61327 (14) | 0.3154 (3) | 0.0534 (5) | |
| H3A | 0.5265 | 0.5476 | 0.3163 | 0.064* | |
| H3B | 0.4511 | 0.6416 | 0.2639 | 0.064* | |
| O1 | 0.21109 (12) | 0.84704 (11) | 0.3128 (2) | 0.0508 (4) | |
| H1B | 0.2450 | 0.8155 | 0.4069 | 0.076* | |
| O2 | 0.32882 (14) | 0.75437 (11) | 0.1058 (2) | 0.0533 (5) | |
| O3 | 0.41587 (12) | 0.90419 (10) | 0.2672 (2) | 0.0494 (4) | |
| O4 | 0.23730 (14) | 0.91989 (11) | 0.0168 (2) | 0.0539 (4) | |
| S1 | 0.30277 (5) | 0.85757 (4) | 0.16657 (8) | 0.0404 (2) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0399 (11) | 0.0385 (12) | 0.0414 (12) | 0.0044 (9) | 0.0057 (10) | −0.0029 (9) |
| C2 | 0.0419 (12) | 0.0400 (12) | 0.0344 (11) | 0.0037 (9) | 0.0069 (9) | −0.0013 (9) |
| C3 | 0.0444 (12) | 0.0581 (15) | 0.0420 (13) | 0.0089 (11) | 0.0057 (10) | 0.0033 (11) |
| C4 | 0.0416 (13) | 0.0658 (17) | 0.0518 (15) | −0.0066 (11) | 0.0051 (11) | −0.0039 (12) |
| C5 | 0.0584 (15) | 0.0548 (16) | 0.0577 (15) | −0.0130 (12) | 0.0151 (12) | −0.0092 (12) |
| C6 | 0.0537 (14) | 0.0407 (13) | 0.0552 (15) | 0.0009 (10) | 0.0103 (12) | −0.0020 (11) |
| C7 | 0.0401 (11) | 0.0386 (12) | 0.0371 (12) | 0.0045 (9) | 0.0073 (9) | −0.0016 (9) |
| N1 | 0.0438 (10) | 0.0322 (10) | 0.0453 (11) | 0.0091 (7) | 0.0017 (8) | −0.0001 (7) |
| N2 | 0.0404 (10) | 0.0343 (10) | 0.0520 (12) | 0.0109 (7) | 0.0013 (8) | −0.0010 (8) |
| N3 | 0.0447 (10) | 0.0400 (11) | 0.0719 (14) | 0.0050 (8) | −0.0019 (10) | −0.0067 (10) |
| O1 | 0.0408 (8) | 0.0495 (10) | 0.0611 (10) | 0.0055 (7) | 0.0047 (8) | 0.0063 (7) |
| O2 | 0.0640 (10) | 0.0331 (9) | 0.0582 (10) | 0.0091 (7) | −0.0047 (8) | −0.0073 (7) |
| O3 | 0.0387 (8) | 0.0372 (9) | 0.0669 (10) | −0.0035 (6) | −0.0086 (7) | 0.0032 (7) |
| O4 | 0.0609 (9) | 0.0381 (9) | 0.0548 (10) | 0.0046 (7) | −0.0153 (8) | 0.0072 (7) |
| S1 | 0.0402 (3) | 0.0288 (3) | 0.0484 (4) | 0.0019 (2) | −0.0045 (2) | 0.0007 (2) |
| C1—N3 | 1.312 (3) | C6—C7 | 1.372 (3) |
| C1—N1 | 1.338 (2) | C6—H6 | 0.9300 |
| C1—N2 | 1.340 (3) | C7—N2 | 1.400 (2) |
| C2—C3 | 1.375 (3) | N1—H1A | 0.8600 |
| C2—C7 | 1.390 (3) | N2—H2A | 0.8600 |
| C2—N1 | 1.401 (3) | N3—H3A | 0.8600 |
| C3—C4 | 1.378 (3) | N3—H3B | 0.8600 |
| C3—H3 | 0.9300 | O1—S1 | 1.5510 (18) |
| C4—C5 | 1.389 (3) | O1—H1B | 0.8200 |
| C4—H4 | 0.9300 | O2—S1 | 1.4549 (16) |
| C5—C6 | 1.398 (3) | O3—S1 | 1.4528 (14) |
| C5—H5 | 0.9300 | O4—S1 | 1.4336 (15) |
| N3—C1—N1 | 126.0 (2) | C6—C7—N2 | 131.49 (19) |
| N3—C1—N2 | 125.21 (19) | C2—C7—N2 | 106.26 (18) |
| N1—C1—N2 | 108.79 (18) | C1—N1—C2 | 109.21 (17) |
| C3—C2—C7 | 121.5 (2) | C1—N1—H1A | 125.4 |
| C3—C2—N1 | 132.04 (19) | C2—N1—H1A | 125.4 |
| C7—C2—N1 | 106.42 (17) | C1—N2—C7 | 109.28 (16) |
| C2—C3—C4 | 116.7 (2) | C1—N2—H2A | 125.4 |
| C2—C3—H3 | 121.7 | C7—N2—H2A | 125.4 |
| C4—C3—H3 | 121.7 | C1—N3—H3A | 120.0 |
| C3—C4—C5 | 122.2 (2) | C1—N3—H3B | 120.0 |
| C3—C4—H4 | 118.9 | H3A—N3—H3B | 120.0 |
| C5—C4—H4 | 118.9 | S1—O1—H1B | 109.5 |
| C4—C5—C6 | 120.8 (2) | O4—S1—O3 | 114.09 (9) |
| C4—C5—H5 | 119.6 | O4—S1—O2 | 113.76 (10) |
| C6—C5—H5 | 119.6 | O3—S1—O2 | 110.13 (9) |
| C7—C6—C5 | 116.5 (2) | O4—S1—O1 | 104.41 (10) |
| C7—C6—H6 | 121.8 | O3—S1—O1 | 106.91 (10) |
| C5—C6—H6 | 121.8 | O2—S1—O1 | 106.88 (10) |
| C6—C7—C2 | 122.2 (2) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N1—H1A···O4i | 0.86 | 2.00 | 2.848 (3) | 167 |
| O1—H1B···O2ii | 0.82 | 1.80 | 2.619 (2) | 176 |
| N2—H2A···O3 | 0.86 | 1.94 | 2.795 (2) | 177 |
| N3—H3A···O3i | 0.86 | 2.09 | 2.899 (3) | 157 |
| N3—H3B···O2 | 0.86 | 2.17 | 2.987 (2) | 158 |
| Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) x, −y+3/2, z+1/2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N1—H1A···O4i | 0.86 | 2.00 | 2.848 (3) | 167 |
| O1—H1B···O2ii | 0.82 | 1.80 | 2.619 (2) | 176 |
| N2—H2A···O3 | 0.86 | 1.94 | 2.795 (2) | 177 |
| N3—H3A···O3i | 0.86 | 2.09 | 2.899 (3) | 157 |
| N3—H3B···O2 | 0.86 | 2.17 | 2.987 (2) | 158 |
| Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) x, −y+3/2, z+1/2. |
WH acknowledges the National Natural Science Foundation of China (No. 20871065) and the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry, for financial aid.
Bruker (2000). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
El-Medania, S. M., Youssef, T. A. & Ramadan, R. M. (2003). J. Mol. Struct. 644, 77–87.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
YeŞilel, O. Z., OdabaŞoğlu, M. & Büyükgüngör, O. (2008). J. Mol. Struct. 874, 151–158.
Several ion-pair adducts of 2-aminobenzimidazole with different organic acids such as picric acid (El-Medania et al., 2003) and squaric acid (YeŞilel et al., 2008) have been reported. Herein, we present a hydrogen sulfate of 2-aminobenzimidazole.
The atom-numbering scheme of the title compound is shown in Fig. 1, while selected bond distances and bond angles are given in Table 1. The benzimidazole skeleton of the title compound is planar and the proton is delocalized within the imidazole ring although it is added to one of the nitrogen atoms. With regard to the hydrogen sulfate anion, the hydrogen atom is added to the O1 atom of SO4 group due to the obviously longer O1–S1 bond length. In the crystal packing, typical π-π stacking can be found between neighbouring aromatic rings with the centroid-to-centroid separation of 3.452 (2) Å. Furthermore, N—H···O and O—H···O hydrogen bonding interactions are found between adjacent molecules to form a three-dimensional network (Fig. 2).