Ammonium 1,3,4,6-tetra­nitro-2,5-di­aza­pentalene

The structure of the ammonium salt of the dianion of 1,3,4,6-tetra­nitro-2,5-di­aza­pentalene is reported, viz. 2NH₄⁺·C₆N₆O₈^2-. Only three atoms of the central 2,5-di­aza­pentalene skeleton are unique, as the anion possesses 2/m symmetry. The ammonium cation forms strong hydrogen bonds to the aza N and nitro O atoms, forming a sheet in the ac plane.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.031
• wR factor = 0.085
• Data-to-parameter ratio = 10.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_733  Alert C Torsion Calc     -4.5(3), Rep   -4.46(12) ......       2.50 su-Rat
                     C2  -C1  -C2  -N2     2.556   1.555   1.555   1.555


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Ammonium 1,3,4,6-tetranitro-2,5-diazapentalene

Crystal data

2H4N^+·C6N6O8^2^−	F(000) = 328
Mr = 320.20	Dx = 1.830 Mg m^−3
Monoclinic, C2/m	Cu Kα radiation, λ = 1.54178 Å
a = 12.1938 (3) Å	Cell parameters from 1485 reflections
b = 9.8825 (2) Å	θ = 11.9–133.9°
c = 5.2130 (1) Å	µ = 1.50 mm^−1
β = 112.294 (1)°	T = 294 K
V = 581.24 (2) Å^3	Prism, red
Z = 2	0.10 × 0.04 × 0.03 mm

Data collection

Bruker CCD area-detector diffractometer	545 independent reflections
Radiation source: fine-focus sealed tube	474 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
φ and ω scans	θmax = 66.8°, θmin = 6.0°
Absorption correction: integration (Wuensch & Prewett, 1965)	h = −14→14
Tmin = 0.874, Tmax = 0.959	k = −11→11
2066 measured reflections	l = −6→5

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.085	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0494P)^2 + 0.1754P] where P = (Fo^2 + 2Fc^2)/3
545 reflections	(Δ/σ)max < 0.001
54 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.05900 (11)	0.33887 (11)	0.3283 (3)	0.0490 (4)
O2	0.18353 (10)	0.24196 (11)	0.1845 (2)	0.0429 (4)
N1	0.12489 (14)	0.0000	0.2920 (3)	0.0284 (4)
N2	0.10873 (10)	0.23672 (11)	0.2915 (2)	0.0300 (3)
N3	0.32158 (16)	0.0000	0.1010 (4)	0.0373 (5)
H3A	0.3874	0.0000	0.2656	0.056*
H3B	0.2534	0.0000	0.1397	0.056*
H3C	0.3227	0.0768	0.0001	0.056*
C1	0.0000	0.07236 (18)	0.5000	0.0248 (4)
C2	0.07853 (12)	0.10816 (13)	0.3675 (3)	0.0265 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0649 (8)	0.0241 (6)	0.0748 (8)	0.0074 (5)	0.0453 (7)	0.0058 (5)
O2	0.0518 (7)	0.0324 (6)	0.0619 (8)	−0.0005 (5)	0.0412 (6)	0.0087 (5)
N1	0.0309 (8)	0.0247 (9)	0.0360 (9)	0.000	0.0200 (7)	0.000
N2	0.0346 (7)	0.0230 (6)	0.0374 (6)	−0.0002 (4)	0.0193 (5)	0.0018 (4)
N3	0.0437 (10)	0.0274 (9)	0.0526 (11)	0.000	0.0318 (9)	0.000
C1	0.0286 (9)	0.0184 (9)	0.0309 (9)	0.000	0.0151 (7)	0.000
C2	0.0295 (7)	0.0217 (7)	0.0327 (7)	−0.0004 (5)	0.0166 (6)	0.0011 (5)

Geometric parameters (Å, º)

O1—N2	1.2295 (16)	N3—H3B	0.9264
O2—N2	1.2379 (16)	N3—H3C	0.9264
N1—C2	1.3364 (16)	C1—C2	1.4217 (14)
N1—C2^i	1.3364 (16)	C1—C2^ii	1.4217 (14)
N2—C2	1.4202 (17)	C1—C1^iii	1.430 (4)
N3—H3A	0.9265
C2—N1—C2^i	106.23 (15)	C2—C1—C2^ii	151.18 (17)
O1—N2—O2	121.81 (11)	C2—C1—C1^iii	104.41 (9)
O1—N2—C2	119.72 (11)	C2^ii—C1—C1^iii	104.41 (9)
O2—N2—C2	118.45 (11)	N1—C2—N2	116.74 (12)
H3A—N3—H3B	109.4	N1—C2—C1	112.47 (12)
H3A—N3—H3C	109.4	N2—C2—C1	130.67 (13)
H3B—N3—H3C	109.4
C2^i—N1—C2—N2	−175.89 (7)	O2—N2—C2—C1	177.68 (12)
C2^i—N1—C2—C1	0.7 (2)	C2^ii—C1—C2—N1	179.58 (12)
O1—N2—C2—N1	172.14 (13)	C1^iii—C1—C2—N1	−0.42 (12)
O2—N2—C2—N1	−6.5 (2)	C2^ii—C1—C2—N2	−4.46 (12)
O1—N2—C2—C1	−3.7 (2)	C1^iii—C1—C2—N2	175.54 (12)

Symmetry codes: (i) x, −y, z; (ii) −x, y, −z+1; (iii) −x, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···O1^iv	0.93	2.53	3.197 (2)	129
N3—H3B···N1	0.93	2.01	2.925 (2)	170
N3—H3C···O2^v	0.93	2.02	2.9412 (14)	172

Symmetry codes: (iv) −x+1/2, −y+1/2, −z+1; (v) −x+1/2, −y+1/2, −z.