Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802013582/ya6116sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802013582/ya6116IIsup2.hkl |
CCDC reference: 197460
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (C-C) = 0.003 Å
- R factor = 0.036
- wR factor = 0.091
- Data-to-parameter ratio = 7.9
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry General Notes
REFLT_03 From the CIF: _diffrn_reflns_theta_max 66.70 From the CIF: _reflns_number_total 1442 Count of symmetry unique reflns 1020 Completeness (_total/calc) 141.37% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 422 Fraction of Friedel pairs measured 0.414 Are heavy atom types Z>Si present no WARNING: CuKa measured Friedel data can be used to determine absolute structure in a light-atom study only if the Friedel fraction is large.
A sample of the title compound was synthesized and crystallized by Clifford L. Coon of the Lawrence Livermore National Laboratory, using methods described in Pagoria et al. (1996).
H atoms were placed at ideal (Sheldrick, 1997) tetrahedral positions and allowed to ride on their bonded neighbors during the refinement, with periodic re-idealization. The H-atom displacement parameters were set to be isotropic, with a value equal to 1.2 times the Ueq value of the neighboring C atom.
Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1997); software used to prepare material for publication: SHELXTL.
Fig. 1. A view of the title compound, bicyclo-HMX, with 50% probability displacement ellipsoids. | |
Fig. 2. A view of the packing of the title compound down the b axis. |
C4H6N8O8 | F(000) = 300 |
Mr = 294.17 | Dx = 1.861 Mg m−3 |
Monoclinic, P21 | Cu Kα radiation, λ = 1.54178 Å |
a = 8.5979 (2) Å | Cell parameters from 2531 reflections |
b = 6.9495 (2) Å | θ = 5.0–66.8° |
c = 8.9726 (2) Å | µ = 1.60 mm−1 |
β = 101.783 (2)° | T = 294 K |
V = 524.83 (2) Å3 | Rectangular prism, colorless |
Z = 2 | 0.6 × 0.14 × 0.10 mm |
Bruker 6K CCD area detector diffractometer | 1442 independent reflections |
Radiation source: fine-focus sealed tube | 1400 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
ϕ and ω scans | θmax = 66.7°, θmin = 5.0° |
Absorption correction: multi-scan SADABS, V.2.03 (Bruker, 2001). | h = −9→9 |
Tmin = 0.384, Tmax = 0.853 | k = −6→7 |
2607 measured reflections | l = −9→10 |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.036 | w = 1/[σ2(Fo2) + (0.0562P)2 + 0.0158P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.091 | (Δ/σ)max = 0.007 |
S = 1.15 | Δρmax = 0.22 e Å−3 |
1442 reflections | Δρmin = −0.23 e Å−3 |
182 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.077 (4) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 484 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.1 (3) |
C4H6N8O8 | V = 524.83 (2) Å3 |
Mr = 294.17 | Z = 2 |
Monoclinic, P21 | Cu Kα radiation |
a = 8.5979 (2) Å | µ = 1.60 mm−1 |
b = 6.9495 (2) Å | T = 294 K |
c = 8.9726 (2) Å | 0.6 × 0.14 × 0.10 mm |
β = 101.783 (2)° |
Bruker 6K CCD area detector diffractometer | 1442 independent reflections |
Absorption correction: multi-scan SADABS, V.2.03 (Bruker, 2001). | 1400 reflections with I > 2σ(I) |
Tmin = 0.384, Tmax = 0.853 | Rint = 0.027 |
2607 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | H-atom parameters constrained |
wR(F2) = 0.091 | Δρmax = 0.22 e Å−3 |
S = 1.15 | Δρmin = −0.23 e Å−3 |
1442 reflections | Absolute structure: Flack (1983), 484 Friedel pairs |
182 parameters | Absolute structure parameter: 0.1 (3) |
1 restraint |
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 | 0.1760 (3) | 0.1529 (3) | 0.2716 (2) | 0.0369 (5) | |
H1A | 0.1579 | 0.0436 | 0.3351 | 0.044* | |
N2 | 0.0277 (2) | 0.2328 (3) | 0.1859 (2) | 0.0467 (5) | |
N2A | −0.0923 (3) | 0.1093 (5) | 0.1244 (2) | 0.0601 (7) | |
O2A | −0.2217 (2) | 0.1836 (5) | 0.0775 (2) | 0.0816 (8) | |
O2B | −0.0570 (3) | −0.0609 (4) | 0.1172 (3) | 0.0761 (7) | |
C3 | −0.0147 (3) | 0.4210 (4) | 0.2334 (3) | 0.0509 (6) | |
H3B | −0.1092 | 0.4161 | 0.2766 | 0.061* | |
H3C | −0.0310 | 0.5121 | 0.1497 | 0.061* | |
N4 | 0.1255 (2) | 0.4685 (3) | 0.3480 (2) | 0.0411 (5) | |
N4A | 0.1029 (3) | 0.5762 (3) | 0.4688 (3) | 0.0557 (6) | |
O4A | −0.0202 (3) | 0.6709 (4) | 0.4475 (3) | 0.0750 (7) | |
O4B | 0.2032 (3) | 0.5730 (4) | 0.5844 (3) | 0.0849 (8) | |
C5 | 0.2508 (2) | 0.3261 (3) | 0.3678 (3) | 0.0372 (5) | |
H5A | 0.2887 | 0.2919 | 0.4751 | 0.045* | |
N6 | 0.3803 (2) | 0.3785 (3) | 0.2938 (2) | 0.0441 (5) | |
N6A | 0.5115 (2) | 0.4669 (3) | 0.3746 (3) | 0.0568 (6) | |
O6A | 0.5030 (3) | 0.5300 (4) | 0.4998 (3) | 0.0753 (6) | |
O6B | 0.6228 (2) | 0.4830 (4) | 0.3108 (4) | 0.0868 (8) | |
C7 | 0.3858 (3) | 0.2678 (4) | 0.1574 (3) | 0.0507 (6) | |
H7A | 0.4932 | 0.2260 | 0.1564 | 0.061* | |
H7B | 0.3456 | 0.3421 | 0.0662 | 0.061* | |
N8 | 0.2824 (2) | 0.1037 (3) | 0.1698 (2) | 0.0424 (5) | |
N8A | 0.3583 (3) | −0.0773 (3) | 0.1965 (3) | 0.0516 (5) | |
O8A | 0.2907 (3) | −0.2001 (3) | 0.2538 (3) | 0.0713 (6) | |
O8B | 0.4802 (3) | −0.0977 (3) | 0.1505 (3) | 0.0730 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0357 (11) | 0.0338 (12) | 0.0428 (10) | −0.0018 (8) | 0.0114 (9) | −0.0001 (9) |
N2 | 0.0319 (10) | 0.0551 (13) | 0.0522 (10) | −0.0002 (9) | 0.0063 (7) | −0.0067 (9) |
N2A | 0.0412 (13) | 0.093 (2) | 0.0468 (11) | −0.0141 (11) | 0.0100 (9) | −0.0120 (12) |
O2A | 0.0392 (12) | 0.136 (2) | 0.0637 (11) | −0.0056 (13) | −0.0039 (8) | −0.0003 (13) |
O2B | 0.0696 (13) | 0.0732 (17) | 0.0866 (14) | −0.0237 (13) | 0.0185 (11) | −0.0329 (12) |
C3 | 0.0439 (12) | 0.0584 (16) | 0.0509 (12) | 0.0153 (11) | 0.0106 (10) | 0.0049 (11) |
N4 | 0.0406 (10) | 0.0355 (11) | 0.0516 (10) | 0.0035 (8) | 0.0197 (8) | −0.0017 (7) |
N4A | 0.0587 (14) | 0.0478 (13) | 0.0689 (13) | −0.0044 (10) | 0.0325 (11) | −0.0147 (10) |
O4A | 0.0735 (14) | 0.0643 (14) | 0.0988 (16) | 0.0199 (11) | 0.0445 (12) | −0.0115 (11) |
O4B | 0.0783 (15) | 0.0970 (19) | 0.0768 (13) | 0.0006 (13) | 0.0099 (12) | −0.0435 (13) |
C5 | 0.0343 (11) | 0.0337 (12) | 0.0448 (10) | −0.0028 (9) | 0.0104 (8) | −0.0002 (8) |
N6 | 0.0323 (9) | 0.0412 (11) | 0.0615 (11) | −0.0035 (8) | 0.0158 (8) | −0.0042 (9) |
N6A | 0.0333 (11) | 0.0443 (13) | 0.0910 (17) | −0.0017 (8) | 0.0088 (10) | 0.0059 (11) |
O6A | 0.0593 (12) | 0.0818 (16) | 0.0775 (12) | −0.0232 (11) | −0.0031 (9) | −0.0162 (12) |
O6B | 0.0380 (12) | 0.0825 (17) | 0.146 (2) | −0.0125 (10) | 0.0333 (13) | −0.0024 (16) |
C7 | 0.0498 (15) | 0.0456 (15) | 0.0641 (14) | 0.0011 (10) | 0.0287 (12) | 0.0040 (11) |
N8 | 0.0415 (11) | 0.0377 (11) | 0.0515 (10) | 0.0028 (8) | 0.0176 (8) | −0.0012 (8) |
N8A | 0.0539 (12) | 0.0422 (12) | 0.0614 (12) | 0.0059 (9) | 0.0179 (10) | −0.0048 (9) |
O8A | 0.0890 (14) | 0.0354 (10) | 0.0979 (15) | 0.0046 (9) | 0.0385 (13) | 0.0051 (10) |
O8B | 0.0633 (13) | 0.0661 (14) | 0.0976 (15) | 0.0230 (10) | 0.0351 (11) | −0.0065 (12) |
C1—N2 | 1.457 (3) | N4A—O4A | 1.228 (3) |
C1—N8 | 1.460 (3) | C5—N6 | 1.455 (3) |
C1—C5 | 1.543 (3) | C5—H5A | 0.9800 |
C1—H1A | 0.9800 | N6—N6A | 1.357 (3) |
N2—N2A | 1.369 (3) | N6—C7 | 1.454 (3) |
N2—C3 | 1.446 (4) | N6A—O6B | 1.216 (3) |
N2A—O2A | 1.221 (3) | N6A—O6A | 1.222 (4) |
N2A—O2B | 1.227 (4) | C7—N8 | 1.464 (3) |
C3—N4 | 1.453 (3) | C7—H7A | 0.9700 |
C3—H3B | 0.9700 | C7—H7B | 0.9700 |
C3—H3C | 0.9700 | N8—N8A | 1.415 (3) |
N4—N4A | 1.364 (3) | N8A—O8A | 1.206 (3) |
N4—C5 | 1.447 (3) | N8A—O8B | 1.211 (3) |
N4A—O4B | 1.206 (3) | ||
N2—C1—N8 | 110.59 (18) | N4—C5—N6 | 113.10 (18) |
N2—C1—C5 | 102.56 (17) | N4—C5—C1 | 104.48 (16) |
N8—C1—C5 | 106.84 (17) | N6—C5—C1 | 102.14 (17) |
N2—C1—H1A | 112.1 | N4—C5—H5A | 112.1 |
N8—C1—H1A | 112.1 | N6—C5—H5A | 112.1 |
C5—C1—H1A | 112.1 | C1—C5—H5A | 112.1 |
N2A—N2—C3 | 118.1 (2) | N6A—N6—C5 | 120.0 (2) |
N2A—N2—C1 | 118.7 (2) | N6A—N6—C7 | 121.49 (19) |
C3—N2—C1 | 115.81 (19) | C5—N6—C7 | 114.30 (19) |
O2A—N2A—O2B | 127.4 (3) | O6B—N6A—O6A | 126.9 (2) |
O2A—N2A—N2 | 115.7 (3) | O6B—N6A—N6 | 116.0 (3) |
O2B—N2A—N2 | 116.8 (2) | O6A—N6A—N6 | 117.0 (2) |
N2—C3—N4 | 101.03 (18) | N6—C7—N8 | 102.92 (16) |
N2—C3—H3B | 111.6 | N6—C7—H7A | 111.2 |
N4—C3—H3B | 111.6 | N8—C7—H7A | 111.2 |
N2—C3—H3C | 111.6 | N6—C7—H7B | 111.2 |
N4—C3—H3C | 111.6 | N8—C7—H7B | 111.2 |
H3B—C3—H3C | 109.4 | H7A—C7—H7B | 109.1 |
N4A—N4—C5 | 120.05 (19) | N8A—N8—C1 | 115.36 (18) |
N4A—N4—C3 | 117.05 (19) | N8A—N8—C7 | 116.06 (18) |
C5—N4—C3 | 114.89 (18) | C1—N8—C7 | 109.46 (17) |
O4B—N4A—O4A | 125.9 (2) | O8A—N8A—O8B | 126.1 (2) |
O4B—N4A—N4 | 118.7 (2) | O8A—N8A—N8 | 117.13 (19) |
O4A—N4A—N4 | 115.4 (2) | O8B—N8A—N8 | 116.6 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O8A | 0.98 | 2.25 | 2.661 (3) | 104 |
C7—H7A···O8B | 0.97 | 2.25 | 2.671 (3) | 105 |
C5—H5A···O6Ai | 0.98 | 2.53 | 3.017 (3) | 111 |
C3—H3B···O6Bii | 0.97 | 2.43 | 3.357 (3) | 160 |
Symmetry codes: (i) −x+1, y−1/2, −z+1; (ii) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C4H6N8O8 |
Mr | 294.17 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 294 |
a, b, c (Å) | 8.5979 (2), 6.9495 (2), 8.9726 (2) |
β (°) | 101.783 (2) |
V (Å3) | 524.83 (2) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 1.60 |
Crystal size (mm) | 0.6 × 0.14 × 0.10 |
Data collection | |
Diffractometer | Bruker 6K CCD area detector diffractometer |
Absorption correction | Multi-scan SADABS, V.2.03 (Bruker, 2001). |
Tmin, Tmax | 0.384, 0.853 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2607, 1442, 1400 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.596 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.091, 1.15 |
No. of reflections | 1442 |
No. of parameters | 182 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.22, −0.23 |
Absolute structure | Flack (1983), 484 Friedel pairs |
Absolute structure parameter | 0.1 (3) |
Computer programs: SMART (Bruker, 2001), SMART, SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 1997), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O8A | 0.98 | 2.25 | 2.661 (3) | 104 |
C7—H7A···O8B | 0.97 | 2.25 | 2.671 (3) | 105 |
C5—H5A···O6Ai | 0.98 | 2.53 | 3.017 (3) | 111 |
C3—H3B···O6Bii | 0.97 | 2.43 | 3.357 (3) | 160 |
Symmetry codes: (i) −x+1, y−1/2, −z+1; (ii) x−1, y, z. |
The title compound, (II), was synthesized from the dipropionyl precursor, (I), with the use of powerful and quite dangerous new nitrolysis agents (Pagoria et al., 1996; Gilardi et al., 2002). This synthesis succeeded only after several more direct synthetic routes from simpler precursors had failed, leading often to the decomposition of the tetraaza ring system. Molecule (II) (Fig. 1) was a target material for several US Department of Defense and Department of Energy laboratories because of its close resemblance to HMX, which is one of the most powerful energetic compounds in explosive and propellant formulations used by the military. The density of (II) was expected to be slightly greater than HMX since it contains fewer H atoms, and its heat of formation was expected to be slightly greater due to added ring strain. However, its density, found in this X-ray analysis to be 1.87 Mg m−3, is slightly less than that of β-HMX (1.91 Mg m−3). Since the detonation pressure and velocity of an explosive are closely correlated with the density, this slight difference was enough to make the calculated properties of (II) equivalent to, but no better than, HMX as an energetic material, despite the added strain of the five-membered ring closures. It is difficult to explain a slight difference in density, but the rigid butterfly shape of the ring system in (II) may have led to inefficient packing. There are three short intermolecular distances, shown as dashed lines in Fig. 2, found in the crystal; N8A···O6Ai [symmetry code: (i) 1 − x, y − 0.5, 1 − z] has a distance of 2.843 (4) Å, which is slightly less than van der Waals (3.07 Å) and two intermolecular C—H.·O hydrogen bonds (Table 1), at H···O 2.43 and 2.53 Å versus the van der Waals distance of 2.72 Å (Rowland & Taylor, 1996). The crystal structure of the precursor molecule, (I), is reported in the preceeding article (Gilardi et al., 2002).