1-Nitro-7,8-di­aza­pentalene

The structure of 1-nitro-7,8-di­aza­pentalene, C₆H₅N₃O₂, is reported. This is a planar molecule, in which the metrical parameters of the two five-membered rings are substantially altered by the effect of the 1-nitro substituent. Additionally, the parameters of the nitro group itself are also perturbed.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.034
• wR factor = 0.093
• Data-to-parameter ratio = 6.8

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.95
PLAT035_ALERT_1_A No _chemical_absolute_configuration info given .          ?

Alert level B
PLAT031_ALERT_4_B Refined Extinction Parameter within Range ......       1.82 Sigma
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C4     -   C5       =       8.60 su

Alert level C
REFNR01_ALERT_3_C  Ratio of reflections to parameters is < 8 for a
            non-centrosymmetric structure, where ZMAX < 18
            sine(theta)/lambda               -0.4985
            Proportion of unique data used    1.0000
            Ratio reflections to parameters   6.7921
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       6.79
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O1A    -   N1       =       5.51 su

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           66.85
           From the CIF: _reflns_number_total                686
           Count of symmetry unique reflns          720
           Completeness (_total/calc)             95.28%
           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

   2 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   4 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
   3 ALERT type 3 Indicator that the structure quality may be low
   3 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-nitro-7,8-diazapentalene

Crystal data

C6H5N3O2	Dx = 1.563 Mg m^−3
Mr = 151.13	Cu Kα radiation, λ = 1.54178 Å
Orthorhombic, P212121	Cell parameters from 2865 reflections
a = 4.0213 (1) Å	θ = 7.7–133.5°
b = 6.9120 (1) Å	µ = 1.04 mm^−1
c = 23.0998 (3) Å	T = 296 K
V = 642.06 (2) Å^3	Plate, orange
Z = 4	0.36 × 0.20 × 0.02 mm
F(000) = 312

Data collection

CCD area detector diffractometer	686 independent reflections
Radiation source: fine-focus sealed tube	659 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
phi and ω scans	θmax = 66.9°, θmin = 3.8°
Absorption correction: multi-scan (Sheldrick, 1999)	h = −4→4
Tmin = 0.790, Tmax = 0.980	k = −8→8
2994 measured reflections	l = −27→27

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)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.093	w = 1/[σ^2(Fo^2) + (0.0526P)^2 + 0.0922P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
686 reflections	Δρmax = 0.11 e Å^−3
101 parameters	Δρmin = −0.13 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.020 (11)

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	0.7961 (6)	0.3363 (3)	0.84970 (8)	0.0547 (6)
N1	0.6784 (5)	0.1572 (3)	0.85832 (8)	0.0635 (6)
O1A	0.7486 (6)	0.0729 (2)	0.90520 (8)	0.0749 (6)
O1B	0.4976 (6)	0.0793 (3)	0.82050 (8)	0.0944 (7)
C2	0.7576 (7)	0.4705 (4)	0.80390 (9)	0.0721 (8)
H2A	0.6402	0.4500	0.7698	0.087*
C3	0.9218 (8)	0.6336 (4)	0.81865 (11)	0.0780 (9)
H3A	0.9362	0.7451	0.7962	0.094*
C4	1.2512 (7)	0.6965 (4)	0.91371 (13)	0.0745 (8)
H4A	1.3363	0.8214	0.9118	0.089*
C5	1.2904 (7)	0.5695 (3)	0.95839 (11)	0.0688 (7)
H5A	1.4071	0.5929	0.9924	0.083*
C6	1.1278 (6)	0.4014 (3)	0.94442 (8)	0.0565 (6)
H6A	1.1143	0.2907	0.9672	0.068*
N7	0.9907 (5)	0.4261 (2)	0.89134 (7)	0.0496 (5)
N8	1.0661 (5)	0.6076 (2)	0.87288 (8)	0.0604 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0580 (12)	0.0549 (11)	0.0512 (10)	0.0057 (12)	0.0005 (10)	−0.0020 (9)
N1	0.0637 (11)	0.0582 (11)	0.0685 (11)	−0.0013 (11)	−0.0061 (10)	−0.0139 (9)
O1A	0.0886 (13)	0.0535 (9)	0.0827 (10)	−0.0135 (11)	−0.0152 (10)	0.0088 (8)
O1B	0.0970 (15)	0.0948 (14)	0.0915 (12)	−0.0124 (14)	−0.0229 (12)	−0.0335 (10)
C2	0.0738 (15)	0.0921 (18)	0.0504 (11)	0.0253 (18)	0.0065 (12)	0.0106 (11)
C3	0.0829 (17)	0.0714 (15)	0.0797 (15)	0.0211 (17)	0.0248 (15)	0.0292 (13)
C4	0.0622 (14)	0.0477 (11)	0.1136 (19)	−0.0110 (14)	0.0214 (15)	−0.0179 (13)
C5	0.0619 (13)	0.0641 (14)	0.0805 (14)	−0.0057 (14)	0.0015 (13)	−0.0171 (12)
C6	0.0571 (12)	0.0575 (12)	0.0548 (10)	−0.0024 (11)	−0.0027 (9)	−0.0008 (9)
N7	0.0514 (10)	0.0416 (8)	0.0557 (9)	0.0006 (8)	0.0060 (8)	0.0018 (7)
N8	0.0625 (11)	0.0434 (9)	0.0752 (11)	0.0031 (10)	0.0202 (10)	0.0096 (8)

Geometric parameters (Å, º)

C1—N1	1.341 (3)	C4—N8	1.349 (3)
C1—N7	1.386 (3)	C4—C5	1.364 (4)
C1—C2	1.415 (3)	C4—H4A	0.9300
N1—O1B	1.258 (2)	C5—C6	1.372 (3)
N1—O1A	1.262 (2)	C5—H5A	0.9300
C2—C3	1.350 (4)	C6—N7	1.355 (3)
C2—H2A	0.9300	C6—H6A	0.9300
C3—N8	1.392 (3)	N7—N8	1.360 (2)
C3—H3A	0.9300
N1—C1—N7	120.63 (19)	C5—C4—H4A	126.3
N1—C1—C2	132.7 (2)	C4—C5—C6	108.2 (2)
N7—C1—C2	106.7 (2)	C4—C5—H5A	125.9
O1B—N1—O1A	121.9 (2)	C6—C5—H5A	125.9
O1B—N1—C1	119.8 (2)	N7—C6—C5	107.5 (2)
O1A—N1—C1	118.33 (19)	N7—C6—H6A	126.3
C3—C2—C1	107.8 (2)	C5—C6—H6A	126.3
C3—C2—H2A	126.1	C6—N7—N8	108.00 (18)
C1—C2—H2A	126.1	C6—N7—C1	143.24 (19)
C2—C3—N8	108.9 (2)	N8—N7—C1	108.74 (18)
C2—C3—H3A	125.6	C4—N8—N7	108.9 (2)
N8—C3—H3A	125.6	C4—N8—C3	143.1 (2)
N8—C4—C5	107.4 (2)	N7—N8—C3	107.9 (2)
N8—C4—H4A	126.3
N7—C1—N1—O1B	178.80 (19)	C2—C1—N7—C6	178.6 (3)
C2—C1—N1—O1B	0.7 (4)	N1—C1—N7—N8	−177.77 (19)
N7—C1—N1—O1A	0.1 (3)	C2—C1—N7—N8	0.7 (2)
C2—C1—N1—O1A	−177.9 (2)	C5—C4—N8—N7	−0.3 (3)
N1—C1—C2—C3	177.7 (2)	C5—C4—N8—C3	179.2 (3)
N7—C1—C2—C3	−0.5 (3)	C6—N7—N8—C4	0.4 (2)
C1—C2—C3—N8	0.1 (3)	C1—N7—N8—C4	179.04 (19)
N8—C4—C5—C6	0.1 (3)	C6—N7—N8—C3	−179.32 (19)
C4—C5—C6—N7	0.1 (3)	C1—N7—N8—C3	−0.7 (2)
C5—C6—N7—N8	−0.3 (2)	C2—C3—N8—C4	−179.2 (3)
C5—C6—N7—C1	−178.2 (3)	C2—C3—N8—N7	0.3 (3)
N1—C1—N7—C6	0.1 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···O1A^i	0.93	2.41	3.288 (3)	158
C2—H2A···O1B^ii	0.93	2.34	3.143 (3)	145

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