Abstract
The asymmetric unit of the title compound, 4C3H2N2O4·C6H6, contains two independent dinitropyrazole molecules and half a benzene solvent molecule, which lies on a crystallographic inversion centre. Each pyrazole ring is essentially planar (mean deviations of 0.009 and 0.002 Å), with the two nitro groups rotated out of the plane [dihedral angles = 11.7 (2)/31.1 (1) and 21.8 (2)/25.0 (1)° for the two molecules].
Related literature
For the biological properties of polynitropyrazoles, see: Alejandre-Durán et al. (1986 ▶); Grigor’ev et al. (1998) ▶; Xuan et al. (1999 ▶). For their detonation properties, see: Keshavarz et al. (2007 ▶); Zaitsev et al. (2009) ▶. For the synthesis, see: Katritzky et al. (2005 ▶). 
Experimental
Crystal data
2C3H2N4O4·0.5C6H6
M r = 355.23
Monoclinic,
a = 7.4579 (15) Å
b = 9.787 (2) Å
c = 19.534 (4) Å
β = 94.87 (3)°
V = 1420.7 (5) Å3
Z = 4
Mo Kα radiation
μ = 0.15 mm−1
T = 123 K
0.30 × 0.20 × 0.20 mm
Data collection
Rigaku R-AXIS RAPID IP diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T min = 0.957, T max = 0.971
3454 measured reflections
3256 independent reflections
1267 reflections with I > 2σ(I)
R int = 0.084
Refinement
R[F 2 > 2σ(F 2)] = 0.060
wR(F 2) = 0.105
S = 0.92
3256 reflections
235 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρmax = 0.27 e Å−3
Δρmin = −0.33 e Å−3
Data collection: RAPID-AUTO (Rigaku, 2000 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku, 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: SHELXL97.
Supplementary Material
Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811015996/zs2110sup1.cif
Structure factors: contains datablocks I. DOI: 10.1107/S1600536811015996/zs2110Isup2.hkl
Supplementary material file. DOI: 10.1107/S1600536811015996/zs2110Isup3.cml
Additional supplementary materials: crystallographic information; 3D view; checkCIF report
Acknowledgments
The authors thank the China North Industries Group Corporation for financial support.
supplementary crystallographic information
Comment
Polynitropyrazole systems have been investigated extensively because of their biological activity (Alejandre-Durán et al., 1986; Grigor'ev et al., 1998; Xuan et al., 1999). Recently, these so called "high energy density materials" have attracted renewed attention because of their favorable detonation performance (Keshavarz et al., 2007; Zaitsev et al., 2009). As a potential candidate, 3,4-dinitropyrazole was synthesized by the nitration of pyrazole (Katritzky et al., 2005). Here we report the crystal structure of the title compound, the benzene solvate 4(C3H2N2O4). C6H6 (I).
In the crystal structure of (I) (Fig. 1), the nitro groups are twisted with respect to the pyrazole plane, making dihedral angles of 11.7° (N1/O1, O2), 31.1° (N2/O3, O4) (molecule A) and 21.8° (N5/O5, O6), 25.0° (N6/O7, O8) (molecule B).
Experimental
The title compound was prepared by the nitrification of pyrazole according to the literature method (Katritzky et al., 2005). Single crystals suitable for X-ray diffraction were obtained by evaporation of a solution of the compound in benzene at room temperature.
Refinement
All H atoms were positioned geometrically and treated as riding, with C—H bond lengths constrained to 0.95 Å and Uiso(H) = 1.2Ueq(C), and the N—H bond = 0.87 Å and Uiso(H) = 1.5Ueq(N).
Figures
Fig. 1.
The molecular structure of the asymmetric unit of the title compound with the atom numbering scheme. The benzene molecule has inversion symmetry [symmetry code (i): -x + 2, -y, -z]. Hydrogen atoms are omitted and displacement ellipsoids are drawn at the 30% probability level.
Crystal data
| 2C3H2N4O4·0.5C6H6 | F(000) = 724 |
| Mr = 355.23 | Dx = 1.661 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 3256 reflections |
| a = 7.4579 (15) Å | θ = 2.1–27.5° |
| b = 9.787 (2) Å | µ = 0.15 mm−1 |
| c = 19.534 (4) Å | T = 123 K |
| β = 94.87 (3)° | Block, colorless |
| V = 1420.7 (5) Å3 | 0.30 × 0.20 × 0.20 mm |
| Z = 4 |
Data collection
| Rigaku R-AXIS RAPID IP diffractometer | 3256 independent reflections |
| Radiation source: fine-focus sealed tube | 1267 reflections with I > 2σ(I) |
| graphite | Rint = 0.084 |
| Detector resolution: 10.00 pixels mm-1 | θmax = 27.5°, θmin = 2.1° |
| ω scans | h = −9→9 |
| Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | k = −12→12 |
| Tmin = 0.957, Tmax = 0.971 | l = −25→25 |
| 3256 measured reflections |
Refinement
| 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)] = 0.060 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.105 | w = 1/[σ2(Fo2) + (0.P)2] where P = (Fo2 + 2Fc2)/3 |
| S = 0.92 | (Δ/σ)max < 0.001 |
| 3256 reflections | Δρmax = 0.27 e Å−3 |
| 235 parameters | Δρmin = −0.33 e Å−3 |
| 2 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0081 (6) |
Special details
| 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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| C1 | 0.9887 (4) | 0.1907 (3) | 0.19586 (16) | 0.0327 (8) | |
| C2 | 1.1357 (4) | 0.1088 (4) | 0.19047 (17) | 0.0420 (9) | |
| H2 | 1.2585 | 0.1359 | 0.1953 | 0.050* | |
| C3 | 0.8410 (4) | 0.1014 (3) | 0.18468 (16) | 0.0289 (8) | |
| C4 | 0.5086 (4) | 0.5510 (3) | 0.09984 (17) | 0.0387 (9) | |
| C5 | 0.3685 (4) | 0.6383 (3) | 0.11466 (16) | 0.0344 (8) | |
| C6 | 0.6606 (4) | 0.6268 (4) | 0.10959 (18) | 0.0538 (11) | |
| H6 | 0.7801 | 0.5975 | 0.1045 | 0.065* | |
| C7 | 1.1648 (8) | 0.0615 (7) | 0.0108 (2) | 0.0902 (16) | |
| H7 | 1.2790 | 0.1045 | 0.0180 | 0.108* | |
| C8 | 1.0067 (11) | 0.1372 (5) | 0.0150 (2) | 0.0921 (19) | |
| H8 | 1.0132 | 0.2318 | 0.0258 | 0.111* | |
| C9 | 0.8469 (8) | 0.0760 (7) | 0.0040 (2) | 0.0880 (17) | |
| H9 | 0.7399 | 0.1279 | 0.0063 | 0.106* | |
| N1 | 0.9970 (4) | 0.3361 (3) | 0.20565 (14) | 0.0409 (7) | |
| N2 | 0.6477 (3) | 0.1259 (3) | 0.18791 (15) | 0.0431 (8) | |
| N3 | 1.0721 (3) | −0.0172 (3) | 0.17704 (15) | 0.0415 (8) | |
| N4 | 0.8896 (3) | −0.0246 (3) | 0.17325 (13) | 0.0364 (7) | |
| N5 | 0.5049 (4) | 0.4072 (3) | 0.08235 (17) | 0.0540 (9) | |
| N6 | 0.1748 (3) | 0.6197 (3) | 0.10954 (15) | 0.0422 (7) | |
| N7 | 0.6079 (4) | 0.7520 (4) | 0.12796 (17) | 0.0533 (9) | |
| N8 | 0.4295 (3) | 0.7621 (3) | 0.13217 (14) | 0.0455 (8) | |
| O1 | 1.1467 (3) | 0.3853 (3) | 0.22096 (13) | 0.0593 (8) | |
| O2 | 0.8580 (3) | 0.4027 (3) | 0.19682 (14) | 0.0638 (8) | |
| O3 | 0.6020 (3) | 0.2140 (3) | 0.22658 (13) | 0.0616 (8) | |
| O4 | 0.5471 (3) | 0.0518 (3) | 0.15166 (14) | 0.0585 (8) | |
| O5 | 0.6340 (4) | 0.3642 (3) | 0.05424 (15) | 0.0840 (10) | |
| O6 | 0.3762 (4) | 0.3390 (3) | 0.09674 (17) | 0.0864 (10) | |
| O7 | 0.1130 (3) | 0.5307 (3) | 0.07052 (13) | 0.0636 (8) | |
| O8 | 0.0861 (3) | 0.6953 (3) | 0.14284 (14) | 0.0631 (8) | |
| H7A | 0.684 (5) | 0.820 (4) | 0.127 (3) | 0.17 (2)* | |
| H3 | 1.138 (3) | −0.091 (2) | 0.1735 (17) | 0.052 (11)* |
Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0275 (18) | 0.0321 (19) | 0.038 (2) | −0.0016 (15) | 0.0019 (15) | 0.0026 (17) |
| C2 | 0.0259 (18) | 0.042 (2) | 0.057 (2) | 0.0014 (17) | −0.0032 (16) | −0.004 (2) |
| C3 | 0.0226 (16) | 0.0290 (18) | 0.0343 (18) | 0.0030 (14) | −0.0015 (14) | 0.0029 (16) |
| C4 | 0.0326 (19) | 0.039 (2) | 0.044 (2) | 0.0008 (17) | −0.0042 (15) | −0.001 (2) |
| C5 | 0.0306 (18) | 0.034 (2) | 0.038 (2) | −0.0019 (16) | −0.0017 (14) | −0.0027 (18) |
| C6 | 0.0279 (19) | 0.070 (3) | 0.063 (3) | −0.001 (2) | −0.0027 (18) | 0.013 (3) |
| C7 | 0.112 (5) | 0.101 (5) | 0.056 (3) | −0.015 (4) | −0.007 (3) | 0.007 (3) |
| C8 | 0.177 (6) | 0.047 (3) | 0.047 (3) | −0.006 (4) | −0.019 (4) | −0.001 (3) |
| C9 | 0.127 (5) | 0.089 (5) | 0.046 (3) | 0.043 (4) | −0.004 (3) | −0.002 (3) |
| N1 | 0.0403 (18) | 0.0392 (19) | 0.0422 (18) | −0.0050 (15) | −0.0027 (14) | −0.0002 (16) |
| N2 | 0.0299 (16) | 0.0406 (19) | 0.058 (2) | −0.0009 (15) | −0.0004 (15) | 0.0044 (18) |
| N3 | 0.0257 (15) | 0.042 (2) | 0.056 (2) | 0.0115 (15) | −0.0010 (13) | −0.0006 (17) |
| N4 | 0.0232 (14) | 0.0343 (17) | 0.0511 (18) | 0.0016 (12) | 0.0007 (12) | 0.0042 (15) |
| N5 | 0.051 (2) | 0.048 (2) | 0.061 (2) | 0.0108 (18) | −0.0078 (17) | −0.0066 (19) |
| N6 | 0.0311 (16) | 0.0382 (18) | 0.056 (2) | −0.0012 (15) | −0.0003 (14) | 0.0049 (18) |
| N7 | 0.045 (2) | 0.049 (2) | 0.063 (2) | −0.0178 (18) | −0.0099 (16) | 0.0041 (19) |
| N8 | 0.0431 (18) | 0.0332 (18) | 0.059 (2) | −0.0049 (15) | −0.0009 (15) | −0.0002 (17) |
| O1 | 0.0446 (15) | 0.0533 (17) | 0.0775 (19) | −0.0211 (14) | −0.0100 (13) | −0.0038 (16) |
| O2 | 0.0497 (15) | 0.0403 (16) | 0.099 (2) | 0.0119 (13) | −0.0072 (15) | 0.0013 (16) |
| O3 | 0.0338 (14) | 0.0637 (19) | 0.089 (2) | 0.0096 (14) | 0.0136 (13) | −0.0253 (18) |
| O4 | 0.0272 (13) | 0.0502 (17) | 0.096 (2) | −0.0024 (12) | −0.0094 (12) | −0.0134 (17) |
| O5 | 0.071 (2) | 0.078 (2) | 0.105 (2) | 0.0246 (17) | 0.0199 (17) | −0.030 (2) |
| O6 | 0.082 (2) | 0.0369 (18) | 0.141 (3) | −0.0096 (16) | 0.015 (2) | −0.0024 (19) |
| O7 | 0.0371 (14) | 0.066 (2) | 0.085 (2) | −0.0130 (14) | −0.0100 (13) | −0.0203 (18) |
| O8 | 0.0405 (15) | 0.0539 (18) | 0.098 (2) | 0.0059 (14) | 0.0231 (14) | −0.0095 (18) |
Geometric parameters (Å, °)
| C1—C2 | 1.370 (4) | C8—C9 | 1.335 (7) |
| C1—C3 | 1.409 (4) | C8—H8 | 0.9500 |
| C1—N1 | 1.436 (4) | C9—C7i | 1.377 (7) |
| C2—N3 | 1.339 (4) | C9—H9 | 0.9500 |
| C2—H2 | 0.9500 | N1—O2 | 1.224 (3) |
| C3—N4 | 1.310 (4) | N1—O1 | 1.229 (3) |
| C3—N2 | 1.468 (3) | N2—O3 | 1.214 (3) |
| C4—C6 | 1.355 (4) | N2—O4 | 1.225 (3) |
| C4—C5 | 1.398 (4) | N3—N4 | 1.359 (3) |
| C4—N5 | 1.448 (4) | N3—H3 | 0.876 (10) |
| C5—N8 | 1.328 (4) | N5—O6 | 1.221 (4) |
| C5—N6 | 1.451 (4) | N5—O5 | 1.223 (4) |
| C6—N7 | 1.344 (4) | N6—O8 | 1.217 (3) |
| C6—H6 | 0.9500 | N6—O7 | 1.222 (3) |
| C7—C9i | 1.377 (7) | N7—N8 | 1.344 (4) |
| C7—C8 | 1.401 (7) | N7—H7A | 0.878 (10) |
| C7—H7 | 0.9500 | ||
| C2—C1—C3 | 104.2 (3) | C8—C9—C7i | 120.8 (5) |
| C2—C1—N1 | 124.3 (3) | C8—C9—H9 | 119.6 |
| C3—C1—N1 | 131.3 (3) | C7i—C9—H9 | 119.6 |
| N3—C2—C1 | 106.3 (3) | O2—N1—O1 | 124.5 (3) |
| N3—C2—H2 | 126.8 | O2—N1—C1 | 118.8 (3) |
| C1—C2—H2 | 126.8 | O1—N1—C1 | 116.6 (3) |
| N4—C3—C1 | 112.7 (3) | O3—N2—O4 | 126.1 (3) |
| N4—C3—N2 | 116.7 (3) | O3—N2—C3 | 118.1 (3) |
| C1—C3—N2 | 130.5 (3) | O4—N2—C3 | 115.7 (3) |
| C6—C4—C5 | 105.5 (3) | C2—N3—N4 | 113.3 (3) |
| C6—C4—N5 | 124.4 (3) | C2—N3—H3 | 125 (2) |
| C5—C4—N5 | 130.0 (3) | N4—N3—H3 | 121 (2) |
| N8—C5—C4 | 111.4 (3) | C3—N4—N3 | 103.4 (3) |
| N8—C5—N6 | 116.7 (3) | O6—N5—O5 | 125.4 (3) |
| C4—C5—N6 | 131.7 (3) | O6—N5—C4 | 118.5 (3) |
| N7—C6—C4 | 106.1 (3) | O5—N5—C4 | 116.1 (3) |
| N7—C6—H6 | 127.0 | O8—N6—O7 | 125.0 (3) |
| C4—C6—H6 | 127.0 | O8—N6—C5 | 118.0 (3) |
| C9i—C7—C8 | 119.4 (5) | O7—N6—C5 | 117.0 (3) |
| C9i—C7—H7 | 120.3 | N8—N7—C6 | 113.4 (3) |
| C8—C7—H7 | 120.3 | N8—N7—H7A | 126 (3) |
| C9—C8—C7 | 119.8 (5) | C6—N7—H7A | 119 (3) |
| C9—C8—H8 | 120.1 | C5—N8—N7 | 103.7 (3) |
| C7—C8—H8 | 120.1 | ||
| C3—C1—C2—N3 | 0.1 (4) | C1—C3—N2—O3 | −29.0 (5) |
| N1—C1—C2—N3 | −175.8 (3) | N4—C3—N2—O4 | −31.6 (4) |
| C2—C1—C3—N4 | −0.1 (4) | C1—C3—N2—O4 | 152.5 (3) |
| N1—C1—C3—N4 | 175.4 (3) | C1—C2—N3—N4 | −0.1 (4) |
| C2—C1—C3—N2 | 175.9 (3) | C1—C3—N4—N3 | 0.0 (4) |
| N1—C1—C3—N2 | −8.6 (6) | N2—C3—N4—N3 | −176.6 (3) |
| C6—C4—C5—N8 | 0.5 (4) | C2—N3—N4—C3 | 0.1 (4) |
| N5—C4—C5—N8 | 176.4 (4) | C6—C4—N5—O6 | 155.9 (4) |
| C6—C4—C5—N6 | 175.6 (3) | C5—C4—N5—O6 | −19.3 (6) |
| N5—C4—C5—N6 | −8.5 (6) | C6—C4—N5—O5 | −23.7 (5) |
| C5—C4—C6—N7 | −1.0 (4) | C5—C4—N5—O5 | 161.0 (3) |
| N5—C4—C6—N7 | −177.2 (3) | N8—C5—N6—O8 | −25.2 (4) |
| C9i—C7—C8—C9 | −0.8 (8) | C4—C5—N6—O8 | 159.9 (3) |
| C7—C8—C9—C7i | 0.8 (9) | N8—C5—N6—O7 | 153.1 (3) |
| C2—C1—N1—O2 | 166.3 (3) | C4—C5—N6—O7 | −21.8 (5) |
| C3—C1—N1—O2 | −8.5 (6) | C4—C6—N7—N8 | 1.2 (4) |
| C2—C1—N1—O1 | −12.0 (5) | C4—C5—N8—N7 | 0.3 (4) |
| C3—C1—N1—O1 | 173.2 (3) | N6—C5—N8—N7 | −175.7 (3) |
| N4—C3—N2—O3 | 146.8 (3) | C6—N7—N8—C5 | −0.9 (4) |
Symmetry codes: (i) −x+2, −y, −z.
Footnotes
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZS2110).
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811015996/zs2110sup1.cif
Structure factors: contains datablocks I. DOI: 10.1107/S1600536811015996/zs2110Isup2.hkl
Supplementary material file. DOI: 10.1107/S1600536811015996/zs2110Isup3.cml
Additional supplementary materials: crystallographic information; 3D view; checkCIF report