(Z)-1,2-Bis(4-nitro­phen­yl)ethene

The title compound, C₁₄H₁₀N₂O₄, is a cis-stilbene derivative with non-crystallographic twofold rotation axis. The two aryl groups reside on the same side of the olefinic bond, and the aryl groups and the olefinic bond are not in the same plane, so the mol­ecule is a non-planar π-conjugate system. The mol­ecules are linked by non-classical C—H...O hydrogen bonds along the b and c directions of the unit cell to form sheets parallel to the bc plane.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.043
• wR factor = 0.116
• Data-to-parameter ratio = 16.2

checkCIF/PLATON results

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Alert level C
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N2     -   C7      ..       6.18 su
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N2

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

In recent years, the stilbene and its derivatives have been the subject of many photophysical investigations (Albota et al., 1998; Reinhardt et al., 1998). Many researches have been directed toward the synthesis of geometrically pure stilbenes, and many perfect methods have been developed (Cella et al., 2006; Ferré-Filmon et al., 2004; Jeffery et al., 2003). Though a number of 4,4'-disubstituted stilbenes are obtained easily, and some trans-stilbene derivatives had been crystallographically characterized (Hulliger et al., 2002; De Borger et al., 2005; Zhang et al., 2005), the crystal stuctures of cis-stilbene derivatives (Traetteberg et al.,1975; Tirado-Rives et al., 1984) has been seldom reported up to the precent, and it is still a challenge topic.

The molecular structure of the title compound is illustrated in Fig. 1, where the molecule adopts a cis configuration with two aryl groups of cis-stilbene resideing on the same side. The bond angles (Table 1) <C(14)—C(13)—C(4) (129.41 (14)°) and <C(13)—C(14)—C(10) (128.71 (13)°) severely deviate from 120° due to the comparatively strong steric hindrance between the two aryl groups. There is a dihedral angle of 56.67° between two planes defined by N(1)/O(1)/O(2)/C(1)—C(6)/C(13) and N(2)/O(3)/O(4)/C(7)—C(12)/C(14). The torsion angles of C(3)—C(4)—C(13)—C(14) (149.55 (16)°) and C(9)—C(10)—C(14)—C(13) (138.17 (17)°) are also significantly deviated from 180°, which indicates that the whole molecule is non-coplanar.

Within the cell of the crystal structure, the molecules are held together by hydrogen bonding interactions (Fig. 2), where the phenyl groups donate hydrogen atoms (H(2) and H(9)) to the oxygen atoms (O(3) and O(4)) to form weak non-classical intermolecular C—H···O hydrogen bonds (Table 2).

Related literature

For synthesis of geometrically pure (cis or trans) stilbenes, see: Cella & Stefani (2006); Ferré-Filmon et al. (2004); Jeffery & Ferber (2003); Shi & Xu (2002). For photophysical investigations on stilbenes and their derivatives, see: Albota et al. (1998); Reinhardt et al. (1998). For related trans-stilbene structures, see: Hulliger et al. (2002); De Borger et al. (2005); Zhang et al. (2005). For rarely reported cis-stilbene structures, see: Traetteberg & Frantsen (1975); Tirado-Rives et al. (1984).

S2. Experimental

The title compound, (I) was synthesized starting from 4-nitrobenzyl(triphenyl) phosphonium chlorine (II) (2.2 mmol), which was obtained by reacting 4-nitrobenzyl chlorine with triphenylphosphite (Shi et al., 2002), In compound (II), 4-nitrobenzaldehyde (2.0 mmol) and NaOH (3.0 mmol) were added to. The mixture was thoroughly ground in an open mortar at room temperature, next it was heated about 15 min at 45–50° C in an oven, and next it was ground again for 1–2 min. Above-mentioned procedure was repeated until the reaction was completed by TLC monitoring. After the mixture was cooled down to the room temperature, water (20 ml) was added to. Then the mixture was extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. Subsequently it was filtered and concentrated. The yellow product was collected and then was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 40:1). Suitable crystals of the title compound were obtained by evaporation of an acetonitrile solution, yield: 7.5% (based on 4-nitrobenzaldehyde). IR (cm^-1, KBr, pellet): v_(C=C) 3081(m), 1591(s), 1488(s), 715(s). ¹HNMR (CDCl₃)(400 MHz; TMS p.p.m.), δ(p.p.m.): 6.83(s, 2H, –C=C–), 7.24–7.35(m, 4H, Ar), 8.10–8.12(d, 4H, Ar).

S3. Refinement

H atoms bonded to C were located geometrically; they were treated as riding, with distances C—H = 0.93 Å and U_iso(H)=1.2 times U_eq(C).

Computing details

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2003); software used to prepare material for publication: SHELXTL (Bruker, 2003).

Figures

	Fig. 1. The structure of the title compound, showing 30% probability ellipsoids and the atom-numbering scheme.
	Fig. 2. A packing diagram for the title compound. Hydrogen bonds are indicated as dashed lines.

(Z)-1,2-Bis(4-nitrophenyl)ethene

Crystal data

C14H10N2O4	F(000) = 560
Mr = 270.24	Dx = 1.426 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 195 reflections
a = 6.8922 (4) Å	θ = 2.0–27.5°
b = 22.8669 (13) Å	µ = 0.11 mm^−1
c = 8.0727 (5) Å	T = 298 K
β = 98.469 (2)°	Block, yellow
V = 1258.41 (13) Å^3	0.50 × 0.20 × 0.19 mm
Z = 4

Data collection

Bruker SMART CCD APEXII diffractometer	2951 independent reflections
Radiation source: fine-focus sealed tube	2179 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
Detector resolution: 8.4 pixels mm^-1	θmax = 27.8°, θmin = 1.8°
ω scans	h = −9→8
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	k = −26→29
Tmin = 0.973, Tmax = 0.981	l = −10→9
9077 measured 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) = 0.116	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0487P)^2 + 0.1997P] where P = (Fo^2 + 2Fc^2)/3
2951 reflections	(Δ/σ)max = 0.001
182 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.16 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
C1	0.2049 (2)	0.73977 (6)	0.61613 (16)	0.0503 (3)
N2	0.74204 (17)	0.46581 (6)	1.07266 (16)	0.0558 (3)
C12	0.7579 (2)	0.56150 (6)	0.93698 (17)	0.0509 (3)
H12A	0.7621	0.5794	1.0409	0.061*
C7	0.74826 (19)	0.50148 (6)	0.92206 (16)	0.0461 (3)
C6	0.2168 (2)	0.67990 (6)	0.63390 (18)	0.0511 (3)
H6A	0.1232	0.6594	0.6824	0.061*
N1	0.0403 (2)	0.77052 (6)	0.67462 (16)	0.0642 (4)
C2	0.3426 (2)	0.77145 (6)	0.54582 (18)	0.0576 (4)
H2A	0.3333	0.8119	0.5367	0.069*
C5	0.3704 (2)	0.65114 (6)	0.57828 (18)	0.0510 (3)
H5A	0.3801	0.6107	0.5900	0.061*
O2	−0.07476 (19)	0.74209 (6)	0.74400 (18)	0.0808 (4)
C10	0.75668 (19)	0.56807 (6)	0.63870 (17)	0.0467 (3)
C11	0.7613 (2)	0.59447 (6)	0.79455 (18)	0.0517 (3)
H11A	0.7667	0.6350	0.8027	0.062*
C4	0.5118 (2)	0.68122 (6)	0.50478 (16)	0.0479 (3)
O4	0.7539 (2)	0.49014 (6)	1.20713 (14)	0.0825 (4)
C9	0.7531 (2)	0.50730 (6)	0.63014 (18)	0.0553 (4)
H9A	0.7554	0.4890	0.5275	0.066*
C13	0.6705 (2)	0.65123 (7)	0.43457 (18)	0.0557 (4)
H13A	0.7087	0.6689	0.3407	0.067*
C8	0.7464 (2)	0.47360 (6)	0.77084 (19)	0.0558 (4)
H8A	0.7408	0.4330	0.7637	0.067*
C3	0.4939 (2)	0.74179 (6)	0.48956 (18)	0.0558 (4)
H3A	0.5863	0.7626	0.4403	0.067*
C14	0.7668 (2)	0.60270 (6)	0.48576 (18)	0.0547 (4)
H14A	0.8520	0.5886	0.4159	0.066*
O3	0.7226 (2)	0.41327 (5)	1.05662 (17)	0.0904 (5)
O1	0.0264 (3)	0.82307 (6)	0.6530 (2)	0.1119 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0558 (8)	0.0524 (8)	0.0401 (7)	0.0075 (6)	−0.0014 (6)	0.0029 (6)
N2	0.0534 (7)	0.0586 (8)	0.0569 (8)	0.0048 (6)	0.0129 (5)	0.0068 (6)
C12	0.0553 (8)	0.0506 (8)	0.0465 (7)	0.0015 (6)	0.0065 (6)	−0.0062 (6)
C7	0.0421 (7)	0.0482 (7)	0.0481 (7)	0.0033 (5)	0.0070 (5)	0.0044 (6)
C6	0.0507 (8)	0.0504 (8)	0.0512 (8)	−0.0043 (6)	0.0040 (6)	0.0036 (6)
N1	0.0750 (9)	0.0613 (8)	0.0553 (7)	0.0157 (7)	0.0059 (6)	0.0005 (6)
C2	0.0779 (11)	0.0422 (7)	0.0512 (8)	0.0033 (7)	0.0042 (7)	0.0103 (6)
C5	0.0537 (8)	0.0424 (7)	0.0559 (8)	−0.0028 (6)	0.0051 (6)	0.0042 (6)
O2	0.0701 (8)	0.0792 (8)	0.0976 (9)	0.0015 (7)	0.0268 (7)	−0.0105 (7)
C10	0.0443 (7)	0.0483 (7)	0.0476 (7)	0.0032 (6)	0.0072 (5)	−0.0004 (6)
C11	0.0595 (9)	0.0410 (7)	0.0545 (8)	0.0008 (6)	0.0074 (6)	−0.0025 (6)
C4	0.0526 (8)	0.0488 (7)	0.0406 (6)	−0.0002 (6)	0.0012 (5)	0.0073 (5)
O4	0.1144 (11)	0.0847 (9)	0.0501 (7)	−0.0059 (7)	0.0176 (6)	0.0030 (6)
C9	0.0694 (10)	0.0494 (8)	0.0475 (8)	0.0031 (7)	0.0096 (7)	−0.0072 (6)
C13	0.0613 (9)	0.0585 (9)	0.0491 (8)	−0.0027 (7)	0.0138 (6)	0.0099 (6)
C8	0.0693 (10)	0.0406 (7)	0.0576 (8)	0.0020 (6)	0.0101 (7)	−0.0024 (6)
C3	0.0639 (9)	0.0515 (8)	0.0515 (8)	−0.0042 (7)	0.0074 (6)	0.0155 (6)
C14	0.0574 (9)	0.0575 (9)	0.0514 (8)	0.0016 (7)	0.0157 (6)	0.0016 (6)
O3	0.1400 (13)	0.0519 (7)	0.0849 (9)	0.0025 (7)	0.0352 (8)	0.0156 (6)
O1	0.1440 (14)	0.0671 (8)	0.1377 (14)	0.0428 (9)	0.0643 (12)	0.0231 (8)

Geometric parameters (Å, º)

C1—C6	1.378 (2)	C5—C4	1.3948 (19)
C1—C2	1.381 (2)	C5—H5A	0.93
C1—N1	1.4709 (19)	C10—C9	1.3913 (19)
N2—O4	1.2119 (16)	C10—C11	1.3916 (19)
N2—O3	1.2135 (17)	C10—C14	1.477 (2)
N2—C7	1.4700 (18)	C11—H11A	0.93
C12—C11	1.378 (2)	C4—C3	1.394 (2)
C12—C7	1.3785 (19)	C4—C13	1.473 (2)
C12—H12A	0.93	C9—C8	1.379 (2)
C7—C8	1.376 (2)	C9—H9A	0.93
C6—C5	1.376 (2)	C13—C14	1.327 (2)
C6—H6A	0.93	C13—H13A	0.93
N1—O1	1.2158 (17)	C8—H8A	0.93
N1—O2	1.2231 (18)	C3—H3A	0.93
C2—C3	1.376 (2)	C14—H14A	0.93
C2—H2A	0.93
C6—C1—C2	122.03 (14)	C9—C10—C11	118.43 (13)
C6—C1—N1	118.60 (13)	C9—C10—C14	119.78 (13)
C2—C1—N1	119.38 (13)	C11—C10—C14	121.70 (13)
O4—N2—O3	122.82 (13)	C12—C11—C10	121.08 (13)
O4—N2—C7	118.66 (13)	C12—C11—H11A	119.5
O3—N2—C7	118.51 (13)	C10—C11—H11A	119.5
C11—C12—C7	118.57 (13)	C3—C4—C5	117.97 (13)
C11—C12—H12A	120.7	C3—C4—C13	119.32 (13)
C7—C12—H12A	120.7	C5—C4—C13	122.61 (13)
C8—C7—C12	122.21 (13)	C8—C9—C10	121.31 (13)
C8—C7—N2	118.63 (13)	C8—C9—H9A	119.3
C12—C7—N2	119.16 (12)	C10—C9—H9A	119.3
C5—C6—C1	118.53 (13)	C14—C13—C4	129.41 (13)
C5—C6—H6A	120.7	C14—C13—H13A	115.3
C1—C6—H6A	120.7	C4—C13—H13A	115.3
O1—N1—O2	123.27 (15)	C7—C8—C9	118.35 (13)
O1—N1—C1	118.33 (15)	C7—C8—H8A	120.8
O2—N1—C1	118.40 (13)	C9—C8—H8A	120.8
C3—C2—C1	118.50 (13)	C2—C3—C4	121.48 (14)
C3—C2—H2A	120.8	C2—C3—H3A	119.3
C1—C2—H2A	120.8	C4—C3—H3A	119.3
C6—C5—C4	121.48 (13)	C13—C14—C10	128.73 (13)
C6—C5—H5A	119.3	C13—C14—H14A	115.6
C4—C5—H5A	119.3	C10—C14—H14A	115.6
C11—C12—C7—C8	1.5 (2)	C14—C10—C11—C12	−177.96 (13)
C11—C12—C7—N2	−179.22 (12)	C6—C5—C4—C3	0.3 (2)
O4—N2—C7—C8	176.23 (14)	C6—C5—C4—C13	−176.04 (13)
O3—N2—C7—C8	−4.7 (2)	C11—C10—C9—C8	2.5 (2)
O4—N2—C7—C12	−3.1 (2)	C14—C10—C9—C8	179.12 (14)
O3—N2—C7—C12	175.97 (14)	C3—C4—C13—C14	149.55 (16)
C2—C1—C6—C5	−0.5 (2)	C5—C4—C13—C14	−34.2 (2)
N1—C1—C6—C5	179.65 (12)	C12—C7—C8—C9	−0.5 (2)
C6—C1—N1—O1	−177.33 (16)	N2—C7—C8—C9	−179.73 (13)
C2—C1—N1—O1	2.8 (2)	C10—C9—C8—C7	−1.6 (2)
C6—C1—N1—O2	3.4 (2)	C1—C2—C3—C4	−1.1 (2)
C2—C1—N1—O2	−176.45 (14)	C5—C4—C3—C2	0.4 (2)
C6—C1—C2—C3	1.1 (2)	C13—C4—C3—C2	176.81 (14)
N1—C1—C2—C3	−179.03 (12)	C4—C13—C14—C10	−7.1 (3)
C1—C6—C5—C4	−0.2 (2)	C9—C10—C14—C13	138.17 (17)
C7—C12—C11—C10	−0.5 (2)	C11—C10—C14—C13	−45.4 (2)
C9—C10—C11—C12	−1.5 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O3^i	0.93	2.45	3.3606 (18)	166
C9—H9A···O4^ii	0.93	2.58	3.4381 (18)	153

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