Aceto­phenone (2,4-di­nitro­phenyl)­hydrazone

Crystals of the title compound, C₁₄H₁₂N₄O₄, were obtained from a condensation reaction of aceto­phenone and 2,4-di­nitro­phenyl­hydrazine. The mol­ecule exhibits a planar structure, with the p-nitro group slightly inclined to the plane. A delocalized double bond is observed in the hydrazone moiety. The separation distances, 3.404 (2) and 3.416 (4) Å, between adjacent parallel phenyl rings indicate π–π aromatic stacking interactions.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.041
• wR factor = 0.142
• Data-to-parameter ratio = 13.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

Some phenylhydrazone derivatives have been shown to be potentially DNA-damaging and mutagenic agents (Okabe et al., 1993). In order to investigate the relationship of the biological activity and the molecular structure, a series of new phenylhydrazone derivatives have been synthesized in this laboratory.

The molecular structure of the title compound, (I), is shown in Fig. 1. The molecule has an approximately planar structure, except for the the N2-nitro group, which is slightly tilted due to intermolcular hydrogen bonding; thus, atoms O3 and O4 deviate from the mean plane of the molecule by 0.284 (3) and −0.199 (3) Å, respectively.

The N3—C1 bond distance of 1.351 (3) Å indicates partial double-bond character. It should be noted that, within the phenyl ring attached to N3, both the C1—C2 bond [1.411 (3) Å] and the C1—C6 bond [1.415 (3) Å] are significantly longer than the average distance of 1.375 (3) Å for the other four C—C bonds; these range from 1.360 (3) to 1.389 (3) Å. A search of the Cambridge Structural Database (Allen & Kennard, 1993) reveals appreciable differences in the C—C distances in free 2,4-dinitrophenylhydrazine (Okabe et al., 1993; Hilgenfeld & Saenger, 1981) and many of its derivatives (Bolte & Dill, 1998; Ohba, 1996; Borwick et al., 1997; Naidu et al., 1996). This is presumably due to the fact that the non-bonding orbital of nitrogen can overlap with the π orbitals of the arene, thus contributing to the iminocyclohexadiene resonance structure.

The N3—N4 bond distance of 1.367 (3) Å is shorter than that found in free 2,4-dinitrophenylhydrazine [1.405 (6) Å; Okabe et al., 1993], while the N4═C7 bond distance of 1.286 (3) Å is longer than the typical N═C bond distance. These values suggest a delocalized double bond in the hydrazone moiety, but not involving C7—C9 [1.480 (3) Å].

The title molecule crystallizes in the E configuration, with the phenyl group (C9–C14) and the N3–2,4-dinitrophenyl group on opposite sides of the C7═N4 double bond; this also means that the methyl group and the N3—H1 bond are on the same side of the N3—N4 bond. The methyl H atoms were located in a difference Fourier map and a torsional parameter was refined for the methyl group. In the present structure, one methyl H atom (H8B) is syn with respect to the C7—C9 bond, the C9—C7—C8—H8B torsion angle being 9.5°. The methyl conformation in this structure is quite different from that calculated by SXGRAPH (Farrugia, 1999) or that reported for p-cyclopropylacetonephenone 2,4-dinitrophenylhydrazone (Drumright et al., 1990). In the former, the H8B···H1 separation is 1.67 Å, whereas in the latter, it is 1.69 Å; in the present structure H8B···H1 is 2.09 Å and thus the methyl conformation better minimizes the steric hindrance between the methyl group and the N3—H1 bond.

An intramolecular hydrogen bond is formed between the N3—H1 group and the adjacent N1-nitro group; this is a common feature of o-nitrophenylhydrazine (Vickery et al., 1985). Intermolecular C—H···O hydrogen bonds exist between the phenyl and nitro groups, as shown in Fig. 1 and Table 2. With the aid of these C—H···O hydrogen bonds, the title molecules are linked to form the supramolecular layered structure. A molecular packing diagram (Fig. 2) shows how neighboring molecules overlap. The separations between adjacent parallel phenyl rings are 3.404 (2) Å (1 − x, −y, −z) and 3.416 (4) Å (2 − x, −y, −z), respectively, indicative of π–π aromatic stacking interactions in the crystal.

S2. Experimental

2,4-Dinitrophenylhydrazine (0.4 g, 0.2 mmol) was dissolved in ethanol (10 ml), then H₂SO₄ solution (98%, 0.5 ml) was added slowly to the ethanol solution with stirring. The solution was heated at about 333 K for several minutes until the solution cleared. Acetophenone (0.24 g, 0.2 mmol) was slowly dropped into the solution with continuous stirring, and the mixture solution was kept at about 333 K for 30 min. When the solution had cooled to room temperature, red powdery crystals appeared. The powdery crystals were separated from the solution and washed with water three times. Recrystallization was performed twice, from chloroform and acetone, respectively, to obtain well shaped crystals.

S3. Refinement

Guided by a difference Fourier map, the methyl H atoms were placed in calculated positions, with C—H = 0.96 Å. A torsional parameter was refined for the methyl group. Other H atoms were placed in calculated positions, with C—H = 0.93 Å and N—H = 0.86 Å; H atoms were included in the final cycles of refinement in the riding mode, with isotropic displacement parameters of 1.2U_eq of the carrier atoms.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; 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: XP (Siemens, 1994); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The structure of (I), with 50% probability displacement ellipsoids. The dashed lines indicate intermolecular hydrogen bonds.
	Fig. 2. A molecular packing diagram, showing the overlap of aromatic rings of neighboring molecules.

(I)

Crystal data

C14H12N4O4	F(000) = 624
Mr = 300.28	Dx = 1.456 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
a = 7.0169 (15) Å	Cell parameters from 24 reflections
b = 13.263 (3) Å	θ = 5.7–12.3°
c = 14.8568 (19) Å	µ = 0.11 mm^−1
β = 97.938 (16)°	T = 298 K
V = 1369.4 (5) Å^3	Prism, orange
Z = 4	0.42 × 0.32 × 0.22 mm

Data collection

Rigaku AFC-7S diffractometer	Rint = 0.025
Radiation source: fine-focus sealed tube	θmax = 26.0°, θmin = 2.1°
Graphite monochromator	h = 0→8
ω/2θ scans	k = 0→16
2921 measured reflections	l = −18→18
2694 independent reflections	3 standard reflections every 150 reflections
1212 reflections with I > 2σ(I)	intensity decay: 0.7%

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)] = 0.041	H-atom parameters constrained
wR(F^2) = 0.142	w = 1/[σ^2(Fo^2) + (0.071P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.96	(Δ/σ)max < 0.001
2694 reflections	Δρmax = 0.17 e Å^−3
201 parameters	Δρmin = −0.15 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: 0.0070 (14)

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	0.7430 (3)	0.37165 (15)	0.12068 (13)	0.0843 (7)
O2	0.8323 (3)	0.22288 (14)	0.16448 (12)	0.0739 (6)
O3	0.5543 (3)	0.45323 (17)	−0.18725 (15)	0.0947 (7)
O4	0.4407 (4)	0.33706 (18)	−0.28025 (15)	0.1042 (9)
N1	0.7623 (3)	0.28222 (17)	0.10492 (14)	0.0583 (6)
N2	0.5239 (4)	0.3645 (2)	−0.20664 (17)	0.0695 (7)
N3	0.7724 (3)	0.07074 (14)	0.05312 (13)	0.0525 (6)
H1	0.8091	0.0879	0.1086	0.063*
N4	0.7777 (3)	−0.02839 (14)	0.02828 (13)	0.0503 (5)
C1	0.7099 (3)	0.14191 (18)	−0.00903 (15)	0.0452 (6)
C2	0.7036 (3)	0.24505 (18)	0.01353 (14)	0.0458 (6)
C3	0.6425 (3)	0.31752 (18)	−0.05165 (17)	0.0501 (6)
H3	0.6406	0.3853	−0.0359	0.060*
C4	0.5853 (3)	0.28758 (19)	−0.13908 (16)	0.0511 (6)
C5	0.5862 (4)	0.1867 (2)	−0.16370 (17)	0.0559 (7)
H5	0.5460	0.1680	−0.2236	0.067*
C6	0.6456 (3)	0.11521 (19)	−0.10039 (16)	0.0513 (6)
H6	0.6439	0.0477	−0.1174	0.062*
C7	0.8440 (3)	−0.09124 (18)	0.09082 (16)	0.0481 (6)
C8	0.9139 (4)	−0.0606 (2)	0.18686 (17)	0.0740 (9)
H8C	0.9744	−0.1172	0.2195	0.089*
H8A	0.8070	−0.0384	0.2156	0.089*
H8B	1.0053	−0.0067	0.1869	0.089*
C9	0.8441 (3)	−0.19816 (18)	0.06226 (17)	0.0481 (6)
C10	0.8947 (4)	−0.2760 (2)	0.12382 (18)	0.0599 (7)
H10	0.9339	−0.2611	0.1847	0.072*
C11	0.8870 (4)	−0.3757 (2)	0.0952 (2)	0.0744 (9)
H11	0.9206	−0.4271	0.1370	0.089*
C12	0.8307 (4)	−0.3987 (2)	0.0064 (2)	0.0731 (9)
H12	0.8249	−0.4657	−0.0123	0.088*
C13	0.7824 (4)	−0.3230 (2)	−0.0559 (2)	0.0684 (8)
H13	0.7456	−0.3388	−0.1168	0.082*
C14	0.7885 (4)	−0.22388 (19)	−0.02818 (17)	0.0558 (7)
H14	0.7549	−0.1733	−0.0707	0.067*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1326 (19)	0.0518 (12)	0.0661 (12)	0.0023 (12)	0.0052 (12)	−0.0176 (10)
O2	0.1090 (15)	0.0635 (12)	0.0453 (10)	0.0068 (11)	−0.0029 (10)	−0.0029 (10)
O3	0.130 (2)	0.0630 (15)	0.0876 (16)	−0.0036 (13)	0.0046 (14)	0.0187 (12)
O4	0.136 (2)	0.1055 (18)	0.0609 (13)	0.0096 (15)	−0.0243 (14)	0.0121 (13)
N1	0.0715 (15)	0.0524 (13)	0.0507 (13)	−0.0041 (12)	0.0080 (11)	−0.0059 (12)
N2	0.0768 (17)	0.0712 (17)	0.0598 (15)	0.0038 (14)	0.0071 (12)	0.0134 (14)
N3	0.0682 (15)	0.0466 (12)	0.0424 (11)	0.0010 (10)	0.0067 (10)	−0.0023 (10)
N4	0.0570 (13)	0.0453 (12)	0.0489 (12)	−0.0008 (10)	0.0085 (10)	−0.0032 (10)
C1	0.0440 (14)	0.0466 (14)	0.0460 (13)	−0.0035 (11)	0.0105 (11)	−0.0032 (12)
C2	0.0487 (14)	0.0483 (14)	0.0403 (12)	−0.0042 (11)	0.0062 (11)	−0.0039 (11)
C3	0.0530 (15)	0.0432 (14)	0.0549 (15)	−0.0033 (12)	0.0107 (13)	−0.0025 (12)
C4	0.0499 (15)	0.0563 (16)	0.0468 (14)	−0.0023 (12)	0.0059 (12)	0.0086 (13)
C5	0.0589 (17)	0.0650 (18)	0.0425 (14)	−0.0063 (14)	0.0030 (12)	−0.0035 (13)
C6	0.0546 (15)	0.0511 (14)	0.0479 (15)	−0.0027 (13)	0.0065 (12)	−0.0071 (12)
C7	0.0441 (14)	0.0543 (16)	0.0462 (14)	0.0034 (12)	0.0069 (11)	0.0019 (12)
C8	0.095 (2)	0.0709 (19)	0.0536 (17)	0.0165 (17)	0.0011 (15)	−0.0049 (14)
C9	0.0401 (13)	0.0500 (15)	0.0550 (15)	0.0027 (11)	0.0094 (11)	0.0042 (12)
C10	0.0576 (17)	0.0598 (18)	0.0613 (16)	0.0042 (14)	0.0049 (13)	0.0087 (14)
C11	0.071 (2)	0.0591 (19)	0.092 (2)	0.0092 (16)	0.0073 (17)	0.0181 (17)
C12	0.0651 (19)	0.0458 (17)	0.107 (3)	0.0031 (14)	0.0068 (17)	−0.0056 (17)
C13	0.0668 (18)	0.0574 (18)	0.0794 (19)	−0.0005 (14)	0.0045 (15)	−0.0138 (16)
C14	0.0608 (17)	0.0493 (15)	0.0562 (16)	0.0036 (13)	0.0040 (13)	0.0010 (13)

Geometric parameters (Å, º)

O1—N1	1.220 (3)	C6—H6	0.9300
O2—N1	1.234 (2)	C7—C9	1.480 (3)
O3—N2	1.223 (3)	C7—C8	1.500 (3)
O4—N2	1.222 (3)	C8—H8C	0.9600
N1—C2	1.450 (3)	C8—H8A	0.9600
N2—C4	1.454 (3)	C8—H8B	0.9600
N3—C1	1.351 (3)	C9—C14	1.389 (3)
N3—N4	1.367 (3)	C9—C10	1.392 (3)
N3—H1	0.8600	C10—C11	1.388 (4)
N4—C7	1.286 (3)	C10—H10	0.9300
C1—C2	1.411 (3)	C11—C12	1.358 (4)
C1—C6	1.415 (3)	C11—H11	0.9300
C2—C3	1.389 (3)	C12—C13	1.376 (4)
C3—C4	1.365 (3)	C12—H12	0.9300
C3—H3	0.9300	C13—C14	1.376 (3)
C4—C5	1.387 (3)	C13—H13	0.9300
C5—C6	1.360 (3)	C14—H14	0.9300
C5—H5	0.9300
O1—N1—O2	121.7 (2)	N4—C7—C9	115.4 (2)
O1—N1—C2	119.1 (2)	N4—C7—C8	123.4 (2)
O2—N1—C2	119.2 (2)	C9—C7—C8	121.3 (2)
O4—N2—O3	122.9 (3)	C7—C8—H8C	109.5
O4—N2—C4	117.9 (3)	C7—C8—H8A	109.5
O3—N2—C4	119.2 (2)	H8C—C8—H8A	109.5
C1—N3—N4	120.39 (19)	C7—C8—H8B	109.5
C1—N3—H1	119.8	H8C—C8—H8B	109.5
N4—N3—H1	119.8	H8A—C8—H8B	109.5
C7—N4—N3	116.7 (2)	C14—C9—C10	117.7 (2)
N3—C1—C2	122.2 (2)	C14—C9—C7	120.1 (2)
N3—C1—C6	120.8 (2)	C10—C9—C7	122.2 (2)
C2—C1—C6	117.0 (2)	C11—C10—C9	120.6 (3)
C3—C2—C1	121.5 (2)	C11—C10—H10	119.7
C3—C2—N1	116.0 (2)	C9—C10—H10	119.7
C1—C2—N1	122.6 (2)	C12—C11—C10	120.4 (3)
C4—C3—C2	118.9 (2)	C12—C11—H11	119.8
C4—C3—H3	120.5	C10—C11—H11	119.8
C2—C3—H3	120.5	C11—C12—C13	120.0 (3)
C3—C4—C5	121.3 (2)	C11—C12—H12	120.0
C3—C4—N2	118.2 (2)	C13—C12—H12	120.0
C5—C4—N2	120.4 (2)	C14—C13—C12	120.1 (3)
C6—C5—C4	120.2 (2)	C14—C13—H13	119.9
C6—C5—H5	119.9	C12—C13—H13	119.9
C4—C5—H5	119.9	C13—C14—C9	121.1 (3)
C5—C6—C1	121.0 (2)	C13—C14—H14	119.4
C5—C6—H6	119.5	C9—C14—H14	119.4
C1—C6—H6	119.5
C1—N3—N4—C7	178.1 (2)	C3—C4—C5—C6	−0.3 (4)
N4—N3—C1—C2	−179.5 (2)	N2—C4—C5—C6	179.3 (2)
N4—N3—C1—C6	1.2 (3)	C4—C5—C6—C1	−0.9 (4)
N3—C1—C2—C3	178.7 (2)	N3—C1—C6—C5	−178.7 (2)
C6—C1—C2—C3	−1.9 (3)	C2—C1—C6—C5	1.9 (3)
N3—C1—C2—N1	−0.4 (4)	N3—N4—C7—C9	178.80 (19)
C6—C1—C2—N1	179.0 (2)	N3—N4—C7—C8	−0.2 (4)
O1—N1—C2—C3	4.9 (3)	N4—C7—C9—C14	4.5 (3)
O2—N1—C2—C3	−174.4 (2)	C8—C7—C9—C14	−176.4 (2)
O1—N1—C2—C1	−175.9 (2)	N4—C7—C9—C10	−174.0 (2)
O2—N1—C2—C1	4.8 (3)	C8—C7—C9—C10	5.0 (4)
C1—C2—C3—C4	0.8 (3)	C14—C9—C10—C11	−0.7 (4)
N1—C2—C3—C4	180.0 (2)	C7—C9—C10—C11	177.8 (2)
C2—C3—C4—C5	0.3 (4)	C9—C10—C11—C12	0.3 (4)
C2—C3—C4—N2	−179.3 (2)	C10—C11—C12—C13	0.5 (5)
O4—N2—C4—C3	−167.0 (2)	C11—C12—C13—C14	−0.9 (4)
O3—N2—C4—C3	11.7 (4)	C12—C13—C14—C9	0.4 (4)
O4—N2—C4—C5	13.4 (4)	C10—C9—C14—C13	0.4 (4)
O3—N2—C4—C5	−167.9 (3)	C7—C9—C14—C13	−178.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H1···O2	0.86	1.97	2.607 (3)	130
C10—H10···O2^i	0.93	2.60	3.450 (3)	153
C14—H14···O4^ii	0.93	2.44	3.174 (4)	136

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