1,3,4-Tri­nitro-7,8-di­aza­pentalene

The structure of 1,3,4-tri­nitro-7,8-di­aza­pentalene, C₆H₃N₅O₆, is reported. In this mol­ecule, while the 7,8-di­aza­pentalene skeleton is planar, the nitro groups are twisted with respect to and deviate from this plane. The metrical parameters of the monosubstituted and disubstituted five-membered rings differ.

Key indicators

• Single-crystal X-ray study
• T = 93 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.048
• wR factor = 0.110
• Data-to-parameter ratio = 5.5

checkCIF/PLATON results

No syntax errors found





Alert level A
ABSTM02_ALERT_3_A  The ratio of expected to reported Tmax/Tmin(RR') is < 0.50
            Tmin and Tmax reported:      0.190     0.981
            Tmin' and Tmax expected:      0.943     0.979
            RR' =      0.201
            Please check that your absorption correction is appropriate.
DENSX01_ALERT_1_A  The ratio of the calculated to measured crystal density
            lies outside the range 0.80 <> 1.20
            Calculated density =      1.829
            Measured density   =      0.000
PLAT061_ALERT_3_A Tmax/Tmin Range Test RR' too Large .............       0.20

Alert level B
REFNR01_ALERT_3_B  Ratio of reflections to parameters is < 6 for a
            non-centrosymmetric structure, where ZMAX < 18
            sine(theta)/lambda                0.3033
            Proportion of unique data used    1.0000
            Ratio reflections to parameters   5.4903
PLAT031_ALERT_4_B Refined Extinction Parameter within Range ......       1.50 Sigma
PLAT089_ALERT_3_B Poor Data / Parameter Ratio (Zmax .LT. 18) .....       5.49
PLAT430_ALERT_2_B Short Inter D...A Contact  O41    ..  N8       =       2.80 Ang.

Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.102
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.10
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT128_ALERT_4_C Non-standard setting of Space group Pca21   ....    Pc21b
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          6
PLAT430_ALERT_2_C Short Inter D...A Contact  O11    ..  O42      =       2.89 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C6 H3 N5 O6

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.35
           From the CIF: _reflns_number_total                851
           Count of symmetry unique reflns          852
           Completeness (_total/calc)             99.88%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present           no

   3 ALERT level A = In general: serious problem
   4 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   7 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Sheldrick, 1999); 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.

1,3,4-trinitro-7,8-diazapentalene

Crystal data

C6H3N5O6	Dx = 1.829 Mg m^−3 Dm = 0 Mg m^−3 Dm measured by not measured
Mr = 241.13	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pc21b	Cell parameters from 2958 reflections
a = 7.0098 (15) Å	θ = 5.8–50.6°
b = 9.363 (2) Å	µ = 0.17 mm^−1
c = 13.344 (3) Å	T = 93 K
V = 875.8 (3) Å^3	Chunk, red
Z = 4	0.35 × 0.22 × 0.13 mm
F(000) = 488

Data collection

Bruker SMART CCD area-detector diffractometer	851 independent reflections
Radiation source: fine-focus sealed tube	795 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.102
φ and ω scans	θmax = 25.4°, θmin = 2.9°
Absorption correction: multi-scan (Sheldrick, 1999)	h = −8→8
Tmin = 0.190, Tmax = 0.981	k = −11→10
4530 measured reflections	l = −16→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.048	H-atom parameters constrained
wR(F^2) = 0.110	w = 1/[σ^2(Fo^2) + (0.0594P)^2 + 0.2676P] where P = (Fo^2 + 2Fc^2)/3
S = 1.18	(Δ/σ)max < 0.001
851 reflections	Δρmax = 0.28 e Å^−3
155 parameters	Δρmin = −0.34 e Å^−3
1 restraint	Extinction correction: SHELXTL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.006 (4)

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
C1	−0.0210 (6)	1.1250 (5)	0.5789 (3)	0.0172 (10)
N1	0.0540 (5)	1.2135 (4)	0.5012 (3)	0.0189 (9)
O11	−0.0596 (5)	1.2597 (4)	0.4384 (3)	0.0261 (8)
O12	0.2252 (4)	1.2397 (4)	0.5033 (3)	0.0238 (8)
C2	0.0634 (6)	1.0841 (5)	0.6673 (3)	0.0164 (10)
H2A	0.1884	1.1067	0.6897	0.020*
C3	−0.0710 (6)	1.0033 (5)	0.7165 (3)	0.0159 (10)
N3	−0.0744 (5)	0.9723 (4)	0.8205 (3)	0.0188 (8)
O31	0.0808 (5)	0.9590 (4)	0.8621 (2)	0.0274 (8)
O32	−0.2306 (4)	0.9651 (4)	0.8632 (2)	0.0265 (8)
C4	−0.4099 (6)	0.9341 (5)	0.6507 (3)	0.0174 (10)
N4	−0.4639 (5)	0.8143 (4)	0.7092 (3)	0.0176 (9)
O41	−0.3388 (4)	0.7534 (4)	0.7570 (3)	0.0238 (8)
O42	−0.6315 (5)	0.7768 (4)	0.7045 (3)	0.0286 (9)
C5	−0.4948 (6)	0.9825 (5)	0.5614 (3)	0.0156 (9)
H5A	−0.6193	0.9603	0.5379	0.019*
C6	−0.3633 (6)	1.0679 (5)	0.5149 (3)	0.0171 (9)
H6A	−0.3805	1.1159	0.4528	0.021*
N7	−0.2042 (5)	1.0722 (4)	0.5725 (3)	0.0158 (8)
N8	−0.2325 (5)	0.9916 (4)	0.6578 (3)	0.0148 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.022 (2)	0.014 (2)	0.016 (2)	−0.0018 (19)	0.0039 (19)	−0.0024 (18)
N1	0.025 (2)	0.015 (2)	0.0170 (19)	0.0001 (17)	0.0069 (19)	0.0014 (17)
O11	0.0347 (19)	0.028 (2)	0.0156 (17)	−0.0029 (16)	−0.0030 (14)	0.0056 (15)
O12	0.0247 (18)	0.0202 (18)	0.0264 (17)	−0.0045 (15)	0.0070 (15)	0.0015 (14)
C2	0.019 (2)	0.015 (2)	0.015 (2)	0.0016 (18)	−0.0015 (17)	−0.0024 (19)
C3	0.020 (2)	0.018 (3)	0.009 (2)	0.001 (2)	−0.0029 (15)	−0.0069 (18)
N3	0.026 (2)	0.018 (2)	0.0119 (17)	−0.0019 (16)	−0.0035 (16)	0.0020 (16)
O31	0.0328 (17)	0.030 (2)	0.0194 (16)	−0.0039 (15)	−0.0133 (14)	0.0033 (16)
O32	0.0334 (18)	0.031 (2)	0.0152 (16)	−0.0018 (16)	0.0036 (14)	0.0017 (14)
C4	0.016 (2)	0.017 (2)	0.020 (2)	−0.001 (2)	0.0038 (17)	−0.0024 (19)
N4	0.022 (2)	0.019 (2)	0.0122 (17)	−0.0014 (17)	0.0005 (16)	0.0041 (16)
O41	0.0293 (16)	0.0189 (17)	0.0233 (16)	0.0003 (15)	0.0001 (16)	0.0053 (15)
O42	0.0271 (19)	0.034 (2)	0.0244 (17)	−0.0133 (17)	−0.0017 (15)	0.0069 (16)
C5	0.0147 (19)	0.017 (2)	0.0155 (19)	0.0024 (19)	−0.0026 (16)	−0.0030 (19)
C6	0.020 (2)	0.021 (2)	0.0108 (19)	0.004 (2)	−0.0011 (17)	0.0006 (19)
N7	0.0224 (19)	0.0156 (19)	0.0092 (17)	0.0036 (16)	0.0032 (14)	0.0018 (15)
N8	0.0224 (19)	0.0119 (18)	0.0099 (17)	0.0023 (16)	0.0033 (14)	0.0021 (15)

Geometric parameters (Å, º)

C1—C2	1.375 (6)	C4—N8	1.359 (5)
C1—N7	1.379 (6)	C4—C5	1.407 (6)
C1—N1	1.428 (6)	C4—N4	1.417 (6)
N1—O12	1.225 (5)	N4—O41	1.226 (5)
N1—O11	1.234 (5)	N4—O42	1.227 (5)
C2—C3	1.375 (6)	C5—C6	1.369 (7)
C2—H2A	0.9500	C5—H5A	0.9500
C3—N8	1.381 (5)	C6—N7	1.355 (5)
C3—N3	1.418 (6)	C6—H6A	0.9500
N3—O31	1.228 (5)	N7—N8	1.380 (5)
N3—O32	1.236 (5)
C2—C1—N7	110.7 (4)	C5—C4—N4	127.5 (4)
C2—C1—N1	128.8 (4)	O41—N4—O42	125.3 (4)
N7—C1—N1	120.4 (4)	O41—N4—C4	117.6 (4)
O12—N1—O11	125.3 (4)	O42—N4—C4	117.0 (4)
O12—N1—C1	117.4 (4)	C6—C5—C4	106.7 (4)
O11—N1—C1	117.3 (4)	C6—C5—H5A	126.6
C3—C2—C1	105.5 (4)	C4—C5—H5A	126.6
C3—C2—H2A	127.2	N7—C6—C5	108.3 (4)
C1—C2—H2A	127.2	N7—C6—H6A	125.8
C2—C3—N8	109.6 (4)	C5—C6—H6A	125.8
C2—C3—N3	126.2 (4)	C6—N7—C1	144.3 (4)
N8—C3—N3	121.7 (4)	C6—N7—N8	109.5 (3)
O31—N3—O32	124.8 (3)	C1—N7—N8	106.2 (3)
O31—N3—C3	116.7 (3)	C4—N8—N7	106.9 (3)
O32—N3—C3	118.5 (3)	C4—N8—C3	145.2 (4)
N8—C4—C5	108.5 (4)	N7—N8—C3	107.8 (3)
N8—C4—N4	121.3 (4)
C2—C1—N1—O12	13.0 (7)	C5—C6—N7—C1	177.8 (6)
N7—C1—N1—O12	−169.4 (4)	C5—C6—N7—N8	−1.0 (5)
C2—C1—N1—O11	−165.7 (5)	C2—C1—N7—C6	179.0 (6)
N7—C1—N1—O11	12.0 (6)	N1—C1—N7—C6	1.0 (9)
N7—C1—C2—C3	0.3 (5)	C2—C1—N7—N8	−2.1 (5)
N1—C1—C2—C3	178.1 (4)	N1—C1—N7—N8	179.8 (4)
C1—C2—C3—N8	1.8 (5)	C5—C4—N8—N7	−1.6 (5)
C1—C2—C3—N3	−160.3 (4)	N4—C4—N8—N7	161.2 (4)
C2—C3—N3—O31	−33.5 (7)	C5—C4—N8—C3	177.1 (6)
N8—C3—N3—O31	166.4 (4)	N4—C4—N8—C3	−20.1 (9)
C2—C3—N3—O32	144.3 (5)	C6—N7—N8—C4	1.7 (5)
N8—C3—N3—O32	−15.8 (6)	C1—N7—N8—C4	−177.6 (3)
N8—C4—N4—O41	−8.9 (6)	C6—N7—N8—C3	−177.6 (4)
C5—C4—N4—O41	150.4 (4)	C1—N7—N8—C3	3.2 (5)
N8—C4—N4—O42	173.9 (4)	C2—C3—N8—C4	178.2 (6)
C5—C4—N4—O42	−26.8 (7)	N3—C3—N8—C4	−18.8 (9)
N8—C4—C5—C6	1.0 (5)	C2—C3—N8—N7	−3.1 (5)
N4—C4—C5—C6	−160.4 (4)	N3—C3—N8—N7	159.9 (4)
C4—C5—C6—N7	0.0 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O42^i	0.95	2.47	3.280 (5)	143
C5—H5A···O32^ii	0.95	2.56	3.275 (5)	132

Symmetry codes: (i) x+1, y+1/2, −z+3/2; (ii) −x−1, y, z−1/2.