N-Nitro-1H-pyrrole-2-carboxamide

In the title compound, C₅H₅N₃O₃, the nitro group is twisted with respect to the amide group, with C—N—N—O torsion angles of 29.0 (2) and −153.66 (14)°. In the crystal, mol­ecules are linked through inter­molecular N—H...O and C—H...O hydrogen bonds, forming supra­molecular chains along the a axis. These chains stack in parallel and form distinct layer motifs in the (001) plane.

Key indicators

• Single-crystal X-ray study
• T = 133 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.043
• wR factor = 0.106
• Data-to-parameter ratio = 13.0

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PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          2
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         14

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S1. Comment

Pyrrole derivatives play an important role in heterocyclic chemistry due to their intrinsic biological activities as antimicrobial agents (Mohamed et al., 2009). The structures of these compounds have been reported extensively, such as 2,3,5-substituted pyrrole derivatives (Ferreira et al., 2002), 1-Benzyl-N-methyl-1H-pyrrole-2-carboxamide (Zeng et al., 2010), 2-(4,5-dibromo-1H-pyrrole-2-carboxamido) propionate (Zeng et al., 2007) and Tetraethyl 1,1'-(ethane-1,2-diyl)bis(2,5- dimethyl-1H-pyrrole-3,4-dicarboxylate) (Wang et al., 2010).

The bond length of N2—C5 for the title compound (1.404 (2) Å) is about 0.07 Å longer than compound 1-Benzyl-N-methyl-1H-pyrrole-2-carboxamide (1.334 (3) Å) (Zeng et al., 2010) (Fig. 1). The unit is nearly co-planar with the twist happens at nitro group (C5—N2—N3—O2 = 29.0 (2), C5—N2—N3—O3 = -153.66 (14)), the maximum deviation of other torsions is C3—C4—C5—N2 = -8.6 (3)°.

In the crystal structure (Fig. 2), molecules are connected through N1—H1N···O3, N2—H2N···O1, C3—H3···O1, C3—H3···O3 (Table 1) hydrogen bonds to form one-dimensional supramolecular chains along the a axis. These supramolecular chains stack in parallel and form distinct layer motif in (0 0 1) plane.

Related literature

For applications of pyrrole derivatives as antimicrobials, see: Mohamed et al. (2009). For the structures of similar pyrrole derivatives, see: Zeng et al. (2007, 2010); Wang et al. (2010); Ferreira et al. (2002). For the synthesis of N,N'-dinitrourea (DNU), see: Goede et al. (2001).

S2. Experimental

Pyrrole (0.67 g, 0.01 mol) was added to a solution of N,N'-dinitrourea (DNU) (1.5 g, 0.01 mol) dissolved in acetonitrile (10 ml), stirred at room temperature for 24 h, the crude compound was obtained after acetonitrile was evaporated. Then the products were dissoved in ethyl acetate, colourless crystals suitable for X-ray crystal diffraction were obtained by slow evaporation of the solution at room temperature. DNU was synthesized according to the literautre (Goede et al., 2001).

S3. Refinement

The hydrogen atoms bonded to N1 and N2 were located from a difference Fourier maps and refined isotropically with N—H = 0.88 (3) Å and 0.88 (2) Å respectively. The remaining hydrogen atoms were geometrically positioned (all C—H = 0.9500 Å).

Computing details

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. Thermal ellipsoid plot of C5H5N3O3 at the 50% probability level; Hydrogen atoms are drawn as spheres of arbitrary radius.
	Fig. 2. Hydrogen-bonded layer structure.

N-Nitro-1H-pyrrole-2-carboxamide

Crystal data

C5H5N3O3	F(000) = 640
Mr = 155.12	Dx = 1.666 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 3166 reflections
a = 9.988 (3) Å	θ = 3.2–27.5°
b = 6.4547 (17) Å	µ = 0.14 mm^−1
c = 19.184 (6) Å	T = 133 K
V = 1236.8 (6) Å^3	Platelet, colourless
Z = 8	0.47 × 0.43 × 0.20 mm

Data collection

Rigaku AFC10/Saturn724+ diffractometer	1214 reflections with I > 2σ(I)
Radiation source: Rotating Anode	Rint = 0.034
Graphite monochromator	θmax = 27.5°, θmin = 3.9°
Detector resolution: 28.5714 pixels mm^-1	h = −12→12
ϕ and ω scans	k = −8→8
8849 measured reflections	l = −24→24
1402 independent reflections

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.106	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0596P)^2 + 0.536P] where P = (Fo^2 + 2Fc^2)/3
1402 reflections	(Δ/σ)max < 0.001
108 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.15 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	0.17512 (12)	0.34028 (18)	0.50500 (5)	0.0219 (3)
O2	0.27334 (11)	0.3909 (2)	0.37665 (6)	0.0256 (3)
O3	0.45611 (12)	0.21230 (19)	0.36431 (6)	0.0255 (3)
N1	0.25340 (14)	0.3489 (2)	0.64493 (7)	0.0207 (3)
N2	0.39562 (13)	0.3045 (2)	0.47037 (7)	0.0182 (3)
N3	0.37143 (13)	0.3012 (2)	0.39910 (7)	0.0178 (3)
C1	0.31849 (18)	0.3310 (3)	0.70652 (8)	0.0235 (4)
H1	0.2800	0.3496	0.7514	0.028*
C2	0.44956 (17)	0.2815 (3)	0.69312 (8)	0.0240 (4)
H2	0.5173	0.2581	0.7270	0.029*
C3	0.46594 (16)	0.2715 (2)	0.62056 (8)	0.0198 (4)
H3	0.5464	0.2417	0.5962	0.024*
C4	0.34176 (15)	0.3137 (2)	0.59132 (8)	0.0160 (3)
C5	0.29335 (15)	0.3204 (2)	0.52027 (8)	0.0158 (3)
H1N	0.169 (3)	0.380 (4)	0.6375 (12)	0.049 (7)*
H2N	0.474 (2)	0.250 (3)	0.4794 (11)	0.032 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0140 (6)	0.0339 (7)	0.0177 (5)	−0.0002 (5)	−0.0004 (4)	0.0003 (5)
O2	0.0181 (6)	0.0398 (7)	0.0188 (6)	0.0049 (5)	−0.0022 (4)	0.0071 (5)
O3	0.0198 (6)	0.0381 (7)	0.0187 (6)	0.0050 (5)	0.0027 (5)	−0.0052 (5)
N1	0.0164 (7)	0.0276 (7)	0.0180 (6)	0.0021 (6)	0.0007 (5)	0.0002 (6)
N2	0.0132 (6)	0.0281 (7)	0.0133 (6)	0.0016 (5)	−0.0022 (5)	0.0011 (5)
N3	0.0153 (6)	0.0241 (7)	0.0141 (6)	−0.0022 (5)	0.0004 (5)	0.0013 (5)
C1	0.0273 (9)	0.0286 (9)	0.0145 (7)	−0.0002 (7)	0.0011 (6)	0.0000 (6)
C2	0.0223 (8)	0.0315 (9)	0.0183 (8)	−0.0013 (7)	−0.0053 (6)	0.0015 (6)
C3	0.0146 (7)	0.0257 (8)	0.0191 (8)	−0.0008 (6)	−0.0001 (6)	0.0010 (6)
C4	0.0147 (7)	0.0176 (7)	0.0158 (7)	−0.0013 (6)	0.0003 (6)	−0.0001 (5)
C5	0.0148 (7)	0.0164 (7)	0.0163 (7)	−0.0011 (6)	−0.0002 (5)	−0.0002 (6)

Geometric parameters (Å, º)

O1—C5	1.2234 (19)	N2—H2N	0.88 (2)
O2—N3	1.2167 (17)	C1—C2	1.372 (2)
O3—N3	1.2206 (17)	C1—H1	0.9500
N1—C1	1.354 (2)	C2—C3	1.403 (2)
N1—C4	1.374 (2)	C2—H2	0.9500
N1—H1N	0.88 (3)	C3—C4	1.388 (2)
N2—N3	1.3886 (18)	C3—H3	0.9500
N2—C5	1.404 (2)	C4—C5	1.447 (2)
C1—N1—C4	109.32 (14)	C1—C2—C3	107.93 (15)
C1—N1—H1N	128.4 (16)	C1—C2—H2	126.0
C4—N1—H1N	122.3 (16)	C3—C2—H2	126.0
N3—N2—C5	123.09 (13)	C4—C3—C2	106.72 (14)
N3—N2—H2N	110.2 (14)	C4—C3—H3	126.6
C5—N2—H2N	123.1 (14)	C2—C3—H3	126.6
O2—N3—O3	126.02 (14)	N1—C4—C3	107.68 (13)
O2—N3—N2	118.77 (13)	N1—C4—C5	119.04 (14)
O3—N3—N2	115.15 (13)	C3—C4—C5	133.25 (14)
N1—C1—C2	108.33 (14)	O1—C5—N2	123.14 (14)
N1—C1—H1	125.8	O1—C5—C4	123.46 (14)
C2—C1—H1	125.8	N2—C5—C4	113.39 (13)
C5—N2—N3—O2	29.0 (2)	C2—C3—C4—C5	−177.88 (16)
C5—N2—N3—O3	−153.66 (14)	N3—N2—C5—O1	−2.7 (2)
C4—N1—C1—C2	−0.71 (19)	N3—N2—C5—C4	177.98 (13)
N1—C1—C2—C3	0.9 (2)	N1—C4—C5—O1	−5.8 (2)
C1—C2—C3—C4	−0.67 (19)	C3—C4—C5—O1	172.13 (17)
C1—N1—C4—C3	0.28 (18)	N1—C4—C5—N2	173.46 (13)
C1—N1—C4—C5	178.72 (14)	C3—C4—C5—N2	−8.6 (3)
C2—C3—C4—N1	0.24 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O3^i	0.88 (3)	2.21 (3)	3.001 (2)	150 (2)
N2—H2N···O1^ii	0.88 (2)	2.11 (2)	2.982 (2)	171.5 (19)
C3—H3···O1^ii	0.95	2.39	3.269 (2)	154
C3—H3···O2^ii	0.95	2.48	3.245 (2)	138

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