(E)-4-Nitro-benzaldehyde oxime.

In the title compound, C(7)H(6)N(2)O(3), the planes containing the CNO and ONO atoms subtend dihedral angles of 5.47 (5) and 8.31 (5)°, respectively, with the benzene ring. In the crystal structure, inter-molecular O-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers with an R(2) (2)(6) graph-set motif.

Related literature

For oximes as therapeutic agents in organophospho­rus poisoning, see: Jokanovic et al. (2009 ▶); Marrs et al. (2006 ▶). For their use as protecting groups in organic synthesis, see: Greene et al. (1999 ▶); Shinada et al. (1995 ▶). For graph-set notation, see: Etter et al. (1990 ▶); Bernstein et al. (1995 ▶). For bond lengths in similar structures, see: Xing, Ding et al. (2007 ▶); Xing, Wang et al. (2007 ▶).

Experimental

Crystal data

C7H6N2O3

M = 166.14

Monoclinic,

a = 3.7737 (2) Å

b = 7.0363 (3) Å

c = 28.6651 (14) Å

β = 91.237 (3)°

V = 760.96 (6) Å3

Z = 4

Mo Kα radiation

μ = 0.12 mm−1

T = 296 K

0.49 × 0.41 × 0.16 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.945, T max = 0.982

7222 measured reflections

1869 independent reflections

1340 reflections with I > 2σ(I)

R int = 0.031

Refinement

R[F 2 > 2σ(F 2)] = 0.066

wR(F 2) = 0.175

S = 1.09

1869 reflections

110 parameters

H-atom parameters constrained

Δρmax = 0.20 e Å−3

Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; 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 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810013978/hg2672sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810013978/hg2672Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C7H6N2O3	F(000) = 344
Mr = 166.14	Dx = 1.450 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1727 reflections
a = 3.7737 (2) Å	θ = 2.8–25.1°
b = 7.0363 (3) Å	µ = 0.12 mm−1
c = 28.6651 (14) Å	T = 296 K
β = 91.237 (3)°	Block, colorless
V = 760.96 (6) Å3	0.49 × 0.41 × 0.16 mm
Z = 4

Bruker APEXII CCD area-detector diffractometer	1869 independent reflections
Radiation source: fine-focus sealed tube	1340 reflections with I > 2σ(I)
graphite	Rint = 0.031
ω scans	θmax = 28.2°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→4
Tmin = 0.945, Tmax = 0.982	k = −9→9
7222 measured reflections	l = −38→37

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.175	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.060P)2 + 0.435P] where P = (Fo2 + 2Fc2)/3
1869 reflections	(Δ/σ)max < 0.001
110 parameters	Δρmax = 0.20 e Å−3
0 restraints	Δρmin = −0.20 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
O3	0.9103 (8)	0.7939 (3)	−0.02398 (6)	0.0848 (8)
H3	0.9673	0.8950	−0.0359	0.127*
O2	0.2494 (7)	0.1865 (3)	0.14956 (8)	0.0857 (8)
N1	0.3651 (6)	0.3009 (3)	0.17705 (8)	0.0575 (6)
N2	0.8746 (6)	0.8191 (3)	0.02418 (7)	0.0562 (6)
C1	0.5229 (6)	0.4774 (3)	0.15885 (8)	0.0425 (5)
C2	0.5707 (6)	0.4913 (3)	0.11163 (8)	0.0426 (5)
H2	0.5092	0.3912	0.0919	0.051*
C3	0.7126 (6)	0.6576 (3)	0.09400 (8)	0.0415 (5)
C7	0.7669 (7)	0.6696 (3)	0.04381 (9)	0.0529 (6)
H7	0.7205	0.5629	0.0255	0.063*
C6	0.6116 (7)	0.6200 (3)	0.18954 (8)	0.0509 (6)
H6	0.5788	0.6059	0.2214	0.061*
C5	0.7516 (7)	0.7856 (3)	0.17149 (9)	0.0549 (6)
H5	0.8135	0.8850	0.1914	0.066*
C4	0.7997 (6)	0.8040 (3)	0.12444 (8)	0.0474 (6)
H4	0.8922	0.9165	0.1128	0.057*
O1	0.3545 (8)	0.2798 (4)	0.21888 (8)	0.1044 (9)

	U11	U22	U33	U12	U13	U23
O3	0.143 (2)	0.0654 (13)	0.0469 (11)	−0.0300 (13)	0.0171 (12)	0.0024 (9)
O2	0.1130 (19)	0.0472 (11)	0.0966 (17)	−0.0354 (12)	−0.0037 (13)	0.0100 (10)
N1	0.0583 (13)	0.0447 (11)	0.0694 (15)	−0.0043 (10)	0.0033 (11)	0.0160 (10)
N2	0.0732 (15)	0.0490 (11)	0.0467 (11)	−0.0115 (10)	0.0070 (10)	0.0029 (9)
C1	0.0405 (11)	0.0353 (10)	0.0518 (13)	−0.0014 (9)	0.0023 (9)	0.0071 (9)
C2	0.0467 (12)	0.0318 (10)	0.0491 (12)	−0.0054 (9)	−0.0020 (9)	−0.0028 (9)
C3	0.0432 (12)	0.0335 (10)	0.0478 (12)	−0.0031 (9)	−0.0004 (9)	0.0015 (9)
C7	0.0677 (16)	0.0416 (12)	0.0496 (14)	−0.0128 (11)	0.0028 (11)	−0.0025 (10)
C6	0.0586 (15)	0.0501 (13)	0.0442 (12)	0.0019 (11)	0.0022 (10)	0.0012 (10)
C5	0.0706 (17)	0.0410 (12)	0.0528 (14)	−0.0082 (11)	−0.0034 (12)	−0.0077 (10)
C4	0.0543 (14)	0.0332 (10)	0.0544 (14)	−0.0095 (9)	−0.0020 (10)	0.0008 (9)
O1	0.155 (3)	0.0918 (17)	0.0674 (15)	−0.0365 (17)	0.0135 (14)	0.0309 (12)

O3—N2	1.401 (3)	C2—H2	0.9300
O3—H3	0.8200	C3—C4	1.385 (3)
O2—N1	1.202 (3)	C3—C7	1.460 (3)
N1—O1	1.210 (3)	C7—H7	0.9300
N1—C1	1.477 (3)	C6—C5	1.385 (3)
N2—C7	1.264 (3)	C6—H6	0.9300
C1—C6	1.371 (3)	C5—C4	1.371 (3)
C1—C2	1.373 (3)	C5—H5	0.9300
C2—C3	1.387 (3)	C4—H4	0.9300
N2—O3—H3	109.5	C2—C3—C7	118.11 (19)
O2—N1—O1	123.2 (2)	N2—C7—C3	122.7 (2)
O2—N1—C1	118.4 (2)	N2—C7—H7	118.7
O1—N1—C1	118.4 (2)	C3—C7—H7	118.7
C7—N2—O3	111.8 (2)	C1—C6—C5	117.8 (2)
C6—C1—C2	123.0 (2)	C1—C6—H6	121.1
C6—C1—N1	118.9 (2)	C5—C6—H6	121.1
C2—C1—N1	118.1 (2)	C4—C5—C6	120.4 (2)
C1—C2—C3	118.63 (19)	C4—C5—H5	119.8
C1—C2—H2	120.7	C6—C5—H5	119.8
C3—C2—H2	120.7	C5—C4—C3	121.0 (2)
C4—C3—C2	119.1 (2)	C5—C4—H4	119.5
C4—C3—C7	122.78 (19)	C3—C4—H4	119.5
O2—N1—C1—C6	171.2 (2)	C4—C3—C7—N2	−5.0 (4)
O1—N1—C1—C6	−7.8 (4)	C2—C3—C7—N2	175.6 (3)
O2—N1—C1—C2	−8.2 (3)	C2—C1—C6—C5	0.8 (4)
O1—N1—C1—C2	172.8 (3)	N1—C1—C6—C5	−178.6 (2)
C6—C1—C2—C3	−0.5 (3)	C1—C6—C5—C4	−0.2 (4)
N1—C1—C2—C3	178.8 (2)	C6—C5—C4—C3	−0.5 (4)
C1—C2—C3—C4	−0.3 (3)	C2—C3—C4—C5	0.8 (4)
C1—C2—C3—C7	179.1 (2)	C7—C3—C4—C5	−178.6 (2)
O3—N2—C7—C3	179.1 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···N2i	0.82	2.12	2.841 (3)	146

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯N2i	0.82	2.12	2.841 (3)	146

Symmetry code: (i) .