Benz­aldehyde 2,4-di­nitro­phenyl­hydrazone

Crystals of the title compound, C₁₃H₁₀N₄O₄, were obtained from a condensation reaction of benz­aldehyde and 2,4-di­nitrophenyl­hydrazine. The mol­ecule assumes an approximately planar E configuration. Within the di­nitro­phenyl moiety, the average distance for the aromatic C—C bonds close to the imino group [1.417 (3) Å] is appreciably longer than the average distance for the other aromatic C—C bonds in the same phenyl ring [1.373 (3) Å]. This increased distance may be a result of the overlap of the non-bonding orbital of the imino N atom with the π orbitals of the arene. It is likely that π–π stacking exists in the crystal structure.

S1. Comment

As some phenylhydrazone derivatives have been shown to be potential DNA-damaging or mutagenic agents (Okabe et al., 1993), a series of new phenylhydrazone derivatives has been synthesized in our laboratory in order to investigate their structure/bioactivity relationship. The structure of the title compound, (I), is reported here as an early result in our study of this new series of compounds.

The molecular structure of (I) is shown in Fig. 1. The molecule assumes a flat coplanar structure, with a maximum atomic deviation of 0.066 (3) Å (atom O2).

The title molecule crystallizes in the E conformation, with the C8-phenyl group and the dinitrophenyl group on opposite sides of the C7═N4 double bond. This agrees with the configuration commonly found in phenylhydrazone derivatives (Bolte & Dill, 1998). The N3—N4 bond distance of 1.374 (2) Å is appreciably shorter than a typical N—N single bond, such as that found in free 2,4-dinitrophenylhydrazine [1.405 (6) Å; Okabe et al., 1993] and suggests the existence of the delocalized double bond in the hydrazone moiety.

The N3—C1 bond distance of 1.350 (2) Å suggests a partial double bond between the amine and the phenyl ring. It is notable that both the C1—C2 [1.420 (3) Å] and the C1—C6 [1.414 (3) Å] bond are appreciably longer than the average distance of 1.373 (3) Å for other C—C bonds in the same phenyl ring; these range from 1.356 (3) to 1.387 (3) Å. Compound (I) is comparable to several derivatives of 2,4-dinitrophenylhydrazone reported previously (Bolte & Dill, 1998; Ohba, 1996; Borwick et al., 1997; Naidu et al., 1996; Shan et al., 2002). This similarity is presumably due to the overlap of the non-bonding orbital of the imino N atom with the π orbitals of the arene, which contributes to the iminocyclohexadiene resonance structure.

Both intramolecular and intermolecular hydrogen bonding exists between imino and nitro groups (as shown in Fig. 1 and Table 2), which results in a short contact of 2.757 (3) Å between O4 and O4 (1 − x, −y, 1 − z) atoms. The weak C—H···O hydrogen bonds exist between nitro and phenyl groups and between carbonyl and phenyl groups, as shown in Fig. 1.

As the planar molecules are packed nearly perpendicular to the crystallographic b axis, the molecules related by a screw axis are nearly coplanar, with a dihedral angle of 5.03 (3)°. Via the hydrogen bonding, the nearly coplanar molecules form a parallel-layered supramolecular structure.

A molecular packing diagram (Fig. 2) shows the overlap arrangement of neighboring molecules. The distances from the C2 (1 − x, 1/2 + y, 1/2 − z) and C9 (1 − x, 1/2 + y, 1/2 − z) atoms to the molecular plane that includes the N1 atom are 3.372 (3) and 3.351 (3) Å, respectively. These strongly suggest the existence of the π–π aromatic stacking interaction between neighboring molecules in the crystal.

S2. Experimental

2,4-Dinitrophenylhydrazine (0.4 g, 0.2 mmol) was dissolved in ethanol (10 ml), and then H₂SO₄ solution (98%) (0.5 ml) was slowly dropped into the ethanol solution with stirring. The solution was heated at about 333 K for several minutes until the solution became transparent. Benzaldehyde (0.21 g, 0.2 mmol) was slowly dropped into the above solution with continuous stirring, then the mixture solution was kept at about 333 K for half an hour. When the solution was cooled to room temperature, fine orange crystals appeared. The fine crystals were separated from the solution and washed with water three times. The recrystallization was performed twice, with chloroform and acetone in turn, to obtain well shaped crystals.

S3. Refinement

All H atoms were placed in calculated positions with C—H distances of 0.93 and N—H distances of 0.86 Å. H atoms were included in the final cycles of refinement in riding mode, with U_iso(H)=1.2U_eq of the carrier atoms.

Computing details

Data collection: MSC/AFC (Molecular Structure Corporation, 1992); cell refinement: MSC/AFC; data reduction: TEXSAN (Molecular Structure Corporation, 1985); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The structure of (I) with 30% probability displacement ellipsoids. Dashed lines show the hydrogen bonding. Symmetry codes: (i) 1 − x, −y, 1 − z; (ii) x − 1, y, z; (iii) x − 1, 1/2 − y, z − 1/2.
	Fig. 2. The molecular-packing diagram in the unit cell, showing the π–π stacking between neighboring molecules. Symmetry code: (i) 1 − x, 1/2 + y, 1/2 − z.

(I)

Crystal data

C13H10N4O4	F(000) = 592
Mr = 286.25	Dx = 1.464 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybc	Cell parameters from 24 reflections
a = 13.290 (3) Å	θ = 4.9–10.8°
b = 6.825 (3) Å	µ = 0.11 mm^−1
c = 14.3316 (18) Å	T = 298 K
β = 92.596 (15)°	Prism, orange
V = 1298.6 (7) Å^3	0.45 × 0.40 × 0.20 mm
Z = 4

Data collection

Rigaku AFC-7S diffractometer	Rint = 0.053
Radiation source: fine-focus sealed tube	θmax = 26.0°, θmin = 2.8°
Graphite monochromator	h = 0→16
ω/2θ scans	k = 0→8
2677 measured reflections	l = −17→17
2564 independent reflections	3 standard reflections every 150 reflections
1258 reflections with I > 2σ(I)	intensity decay: 0.2%

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)] = 0.040	H-atom parameters constrained
wR(F^2) = 0.141	w = 1/[σ^2(Fo^2) + (0.0715P)^2 + 0.0073P] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
2564 reflections	Δρmax = 0.18 e Å^−3
191 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.016 (2)

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	1.01944 (13)	0.1347 (4)	0.25135 (15)	0.1147 (10)
O2	1.03126 (14)	0.1295 (4)	0.39982 (15)	0.1215 (10)
O3	0.74168 (12)	0.0892 (3)	0.57597 (9)	0.0638 (5)
O4	0.59199 (10)	0.0913 (2)	0.51373 (10)	0.0560 (4)
N1	0.98211 (15)	0.1281 (4)	0.32660 (17)	0.0754 (7)
N2	0.68439 (12)	0.0935 (3)	0.50696 (10)	0.0409 (4)
N3	0.56126 (12)	0.0945 (2)	0.33133 (11)	0.0405 (4)
H3A	0.5301	0.0856	0.3824	0.049*
N4	0.50861 (12)	0.0994 (2)	0.24659 (11)	0.0415 (4)
C1	0.66282 (13)	0.1039 (3)	0.33295 (13)	0.0368 (5)
C2	0.72528 (14)	0.1011 (3)	0.41597 (12)	0.0363 (5)
C3	0.82919 (14)	0.1075 (3)	0.41344 (14)	0.0440 (5)
H3	0.8688	0.1041	0.4686	0.053*
C4	0.87289 (15)	0.1188 (3)	0.32939 (15)	0.0482 (6)
C5	0.81507 (15)	0.1264 (3)	0.24646 (14)	0.0499 (6)
H5	0.8460	0.1362	0.1897	0.060*
C6	0.71319 (15)	0.1193 (3)	0.24841 (14)	0.0456 (5)
H6	0.6752	0.1247	0.1923	0.055*
C7	0.41286 (14)	0.0933 (3)	0.24870 (13)	0.0403 (5)
H7	0.3826	0.0849	0.3058	0.048*
C8	0.35017 (14)	0.0992 (3)	0.16234 (13)	0.0385 (5)
C9	0.24624 (15)	0.1026 (3)	0.16693 (15)	0.0461 (5)
H9	0.2171	0.0995	0.2247	0.055*
C10	0.18576 (17)	0.1104 (3)	0.08584 (17)	0.0559 (6)
H10	0.1160	0.1125	0.0891	0.067*
C11	0.22892 (19)	0.1150 (3)	0.00054 (17)	0.0591 (6)
H11	0.1882	0.1208	−0.0539	0.071*
C12	0.33218 (18)	0.1110 (3)	−0.00477 (15)	0.0540 (6)
H12	0.3609	0.1132	−0.0627	0.065*
C13	0.39282 (15)	0.1038 (3)	0.07551 (14)	0.0452 (5)
H13	0.4625	0.1020	0.0717	0.054*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0510 (12)	0.211 (3)	0.0847 (14)	−0.0010 (15)	0.0302 (11)	0.0121 (16)
O2	0.0442 (10)	0.235 (3)	0.0837 (14)	−0.0131 (15)	−0.0099 (10)	0.0204 (17)
O3	0.0552 (9)	0.1038 (14)	0.0318 (7)	−0.0042 (10)	−0.0064 (6)	−0.0062 (9)
O4	0.0403 (8)	0.0852 (12)	0.0430 (8)	−0.0009 (9)	0.0077 (6)	−0.0002 (8)
N1	0.0392 (11)	0.117 (2)	0.0709 (14)	−0.0012 (12)	0.0078 (10)	0.0095 (15)
N2	0.0443 (10)	0.0467 (10)	0.0318 (8)	−0.0002 (8)	0.0015 (7)	−0.0033 (8)
N3	0.0378 (9)	0.0525 (11)	0.0310 (8)	−0.0024 (9)	0.0002 (6)	0.0025 (8)
N4	0.0400 (9)	0.0468 (11)	0.0374 (8)	−0.0007 (9)	−0.0028 (7)	0.0016 (9)
C1	0.0365 (10)	0.0374 (11)	0.0363 (10)	0.0000 (10)	−0.0004 (8)	0.0001 (10)
C2	0.0383 (10)	0.0383 (11)	0.0325 (10)	−0.0012 (10)	0.0030 (8)	−0.0003 (9)
C3	0.0408 (11)	0.0507 (13)	0.0399 (11)	−0.0012 (11)	−0.0042 (8)	−0.0004 (11)
C4	0.0350 (10)	0.0584 (15)	0.0515 (12)	−0.0007 (11)	0.0054 (9)	0.0035 (12)
C5	0.0439 (12)	0.0664 (16)	0.0401 (11)	0.0005 (11)	0.0109 (9)	0.0034 (11)
C6	0.0475 (12)	0.0572 (15)	0.0318 (10)	−0.0013 (11)	−0.0012 (8)	0.0008 (10)
C7	0.0396 (11)	0.0437 (12)	0.0377 (10)	−0.0013 (10)	0.0035 (8)	0.0030 (10)
C8	0.0384 (10)	0.0350 (11)	0.0417 (11)	0.0001 (10)	−0.0021 (8)	−0.0001 (10)
C9	0.0405 (11)	0.0482 (13)	0.0495 (12)	0.0008 (11)	0.0008 (9)	−0.0016 (11)
C10	0.0414 (11)	0.0544 (15)	0.0708 (16)	0.0027 (12)	−0.0106 (11)	−0.0028 (13)
C11	0.0663 (15)	0.0547 (15)	0.0539 (13)	0.0056 (13)	−0.0237 (11)	−0.0007 (12)
C12	0.0647 (15)	0.0546 (15)	0.0420 (12)	−0.0004 (13)	−0.0042 (10)	−0.0020 (12)
C13	0.0412 (11)	0.0495 (13)	0.0448 (11)	0.0010 (11)	0.0004 (9)	0.0011 (11)

Geometric parameters (Å, º)

O1—N1	1.208 (3)	C5—C6	1.356 (3)
O2—N1	1.211 (3)	C5—H5	0.930
O3—N2	1.221 (2)	C6—H6	0.930
O4—N2	1.236 (2)	C7—C8	1.461 (3)
N1—C4	1.455 (3)	C7—H7	0.930
N2—C2	1.436 (2)	C8—C9	1.386 (3)
N3—C1	1.350 (2)	C8—C13	1.391 (3)
N3—N4	1.374 (2)	C9—C10	1.384 (3)
N3—H3A	0.860	C9—H9	0.930
N4—C7	1.275 (2)	C10—C11	1.374 (4)
C1—C6	1.414 (3)	C10—H10	0.930
C1—C2	1.420 (3)	C11—C12	1.378 (3)
C2—C3	1.384 (3)	C11—H11	0.930
C3—C4	1.363 (3)	C12—C13	1.375 (3)
C3—H3	0.930	C12—H12	0.930
C4—C5	1.387 (3)	C13—H13	0.930
O1—N1—O2	123.1 (2)	C5—C6—C1	122.13 (19)
O1—N1—C4	118.5 (2)	C5—C6—H6	118.9
O2—N1—C4	118.4 (2)	C1—C6—H6	118.9
O3—N2—O4	121.42 (16)	N4—C7—C8	120.70 (18)
O3—N2—C2	119.25 (16)	N4—C7—H7	119.7
O4—N2—C2	119.33 (15)	C8—C7—H7	119.7
C1—N3—N4	118.85 (15)	C9—C8—C13	119.31 (19)
C1—N3—H3A	120.6	C9—C8—C7	119.44 (18)
N4—N3—H3A	120.6	C13—C8—C7	121.25 (18)
C7—N4—N3	116.55 (16)	C10—C9—C8	120.2 (2)
N3—C1—C6	120.01 (17)	C10—C9—H9	119.9
N3—C1—C2	124.04 (17)	C8—C9—H9	119.9
C6—C1—C2	115.95 (17)	C11—C10—C9	119.9 (2)
C3—C2—C1	121.59 (17)	C11—C10—H10	120.1
C3—C2—N2	116.36 (16)	C9—C10—H10	120.1
C1—C2—N2	122.04 (16)	C10—C11—C12	120.4 (2)
C4—C3—C2	119.39 (18)	C10—C11—H11	119.8
C4—C3—H3	120.3	C12—C11—H11	119.8
C2—C3—H3	120.3	C13—C12—C11	120.1 (2)
C3—C4—C5	121.19 (18)	C13—C12—H12	119.9
C3—C4—N1	119.5 (2)	C11—C12—H12	119.9
C5—C4—N1	119.3 (2)	C12—C13—C8	120.1 (2)
C6—C5—C4	119.73 (19)	C12—C13—H13	119.9
C6—C5—H5	120.1	C8—C13—H13	119.9
C4—C5—H5	120.1
C1—N3—N4—C7	−178.93 (18)	O2—N1—C4—C5	177.0 (3)
N4—N3—C1—C6	0.2 (3)	C3—C4—C5—C6	−1.0 (4)
N4—N3—C1—C2	179.70 (18)	N1—C4—C5—C6	−179.5 (2)
N3—C1—C2—C3	178.80 (19)	C4—C5—C6—C1	−0.1 (4)
C6—C1—C2—C3	−1.7 (3)	N3—C1—C6—C5	−179.1 (2)
N3—C1—C2—N2	−1.9 (3)	C2—C1—C6—C5	1.4 (3)
C6—C1—C2—N2	177.61 (18)	N3—N4—C7—C8	179.53 (17)
O3—N2—C2—C3	−1.4 (3)	N4—C7—C8—C9	−176.7 (2)
O4—N2—C2—C3	178.61 (19)	N4—C7—C8—C13	2.6 (3)
O3—N2—C2—C1	179.25 (19)	C13—C8—C9—C10	0.0 (3)
O4—N2—C2—C1	−0.8 (3)	C7—C8—C9—C10	179.3 (2)
C1—C2—C3—C4	0.7 (3)	C8—C9—C10—C11	0.0 (3)
N2—C2—C3—C4	−178.69 (19)	C9—C10—C11—C12	0.3 (4)
C2—C3—C4—C5	0.8 (4)	C10—C11—C12—C13	−0.5 (4)
C2—C3—C4—N1	179.2 (2)	C11—C12—C13—C8	0.4 (4)
O1—N1—C4—C3	178.7 (3)	C9—C8—C13—C12	−0.2 (3)
O2—N1—C4—C3	−1.5 (4)	C7—C8—C13—C12	−179.5 (2)
O1—N1—C4—C5	−2.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···O4	0.86	2.02	2.628 (2)	127
N3—H3A···O4^i	0.86	2.55	3.331 (2)	151
C9—H9···O1^ii	0.93	2.68	3.306 (3)	125
C10—H10···O1^ii	0.93	2.71	3.319 (3)	124
C11—H11···O2^iii	0.93	2.75	3.418 (3)	129

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