The title compound, 4′-methoxy-α,2,3′,4-tetranitrostilbene, C
15H
10N
4O
9, crystallizes in the centrosymmetric space group
P2
1/
c with one molecule in the asymmetric unit. The phenyl rings are inclined to one another and form a dihedral angle of 57.4 (1)°. The size of this angle is a result of intermolecular C—H
O interactions involving the phenyl H atoms. The torsion angle between the phenyl rings, −7.5 (3)°, indicates a
cis geometry between them. The methoxy group is almost coplanar with the phenyl ring, and the nitro groups are twisted with respect to the phenyl rings because of the short H
O contacts. The crystal packing is stabilized by C—H
O hydrogen bonds, and the intermolecular hydrogen bonds form a
C(12) graph-set chain running along the [010] direction.
Supporting information
CCDC reference: 208029
To 5mM (1.80 g) of 4'-methoxy-2,4-dinitrostilbene, 5.5 ml of fuming nitric acid was added slowly with stirring. The reaction mixture was kept at 363 K for five minutes. After cooling to 298–303 K, the reaction mixture was poured over crushed ice, the crude product was filtered off, washed with water, desiccated over anhydrous CaCl2 and recrystallized from acetone (Saravanan & Srinivasan, 2002).
All the H atoms were geometrically fixed and allowed to ride on their parent atoms, with C—H = 0.93–0.96 Å and Uiso = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for other H atoms.
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: TEXSAN (Molecular Structure Corporation, 1985); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: SHELX97 and PARST (Nardelli, 1995).
4'-methoxy-
α,2,3'4-tetranitrostilbene
top
Crystal data top
C15H10N4O9 | F(000) = 800 |
Mr = 390.27 | Dx = 1.521 Mg m−3 |
Monoclinic, P21/c | Cu Kα radiation, λ = 1.54178 Å |
a = 7.096 (4) Å | Cell parameters from 25 reflections |
b = 8.550 (3) Å | θ = 5.4–67.9° |
c = 28.101 (5) Å | µ = 1.12 mm−1 |
β = 90.87 (3)° | T = 293 K |
V = 1704.7 (12) Å3 | Block, colorless |
Z = 4 | 0.6 × 0.40 × 0.35 mm |
Data collection top
Enraf-Nonius CAD-4 diffractometer | Rint = 0.034 |
Radiation source: fine-focus sealed tube | θmax = 67.9°, θmin = 5.4° |
Graphite monochromator | h = 0→8 |
Non–profiled w/2θ scans | k = −10→10 |
6505 measured reflections | l = −33→33 |
3105 independent reflections | 3 standard reflections every 100 reflections |
2787 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.051 | H-atom parameters constrained |
wR(F2) = 0.153 | w = 1/[σ2(Fo2) + (0.0939P)2 + 0.330P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.001 |
3105 reflections | Δρmax = 0.40 e Å−3 |
255 parameters | Δρmin = −0.21 e Å−3 |
0 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.035 (2) |
Crystal data top
C15H10N4O9 | V = 1704.7 (12) Å3 |
Mr = 390.27 | Z = 4 |
Monoclinic, P21/c | Cu Kα radiation |
a = 7.096 (4) Å | µ = 1.12 mm−1 |
b = 8.550 (3) Å | T = 293 K |
c = 28.101 (5) Å | 0.6 × 0.40 × 0.35 mm |
β = 90.87 (3)° | |
Data collection top
Enraf-Nonius CAD-4 diffractometer | Rint = 0.034 |
6505 measured reflections | 3 standard reflections every 100 reflections |
3105 independent reflections | intensity decay: none |
2787 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.051 | 0 restraints |
wR(F2) = 0.153 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.40 e Å−3 |
3105 reflections | Δρmin = −0.21 e Å−3 |
255 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.1874 (2) | 0.1860 (2) | 0.52822 (6) | 0.0855 (5) | |
O2 | 0.4469 (3) | 0.2238 (2) | 0.56743 (5) | 0.0942 (6) | |
O3 | 1.1528 (3) | −0.0702 (3) | 0.34689 (7) | 0.1049 (7) | |
O4 | 1.2314 (2) | 0.0131 (3) | 0.41697 (7) | 0.1040 (6) | |
O5 | 1.1444 (3) | 0.2907 (3) | 0.32908 (8) | 0.1183 (8) | |
O6 | 1.1386 (3) | 0.2623 (3) | 0.25500 (8) | 0.1344 (9) | |
O7 | 0.3657 (4) | −0.0256 (3) | 0.21271 (7) | 0.1239 (9) | |
O8 | 0.5474 (4) | 0.1373 (2) | 0.17860 (5) | 0.1054 (7) | |
O9 | 0.1993 (2) | 0.43552 (17) | 0.46735 (5) | 0.0709 (4) | |
N1 | 0.3538 (3) | 0.22431 (18) | 0.53070 (5) | 0.0622 (4) | |
N2 | 1.1235 (2) | 0.0062 (2) | 0.38283 (7) | 0.0730 (5) | |
N3 | 1.0710 (3) | 0.2431 (2) | 0.29384 (7) | 0.0737 (5) | |
N4 | 0.5007 (4) | 0.0607 (2) | 0.21280 (6) | 0.0830 (6) | |
C1 | 0.6226 (2) | 0.19939 (19) | 0.47871 (5) | 0.0501 (4) | |
H1 | 0.6785 | 0.1353 | 0.5016 | 0.060* | |
C2 | 0.4501 (2) | 0.26703 (19) | 0.48702 (5) | 0.0507 (4) | |
C3 | 0.3652 (2) | 0.37135 (19) | 0.45504 (6) | 0.0524 (4) | |
C4 | 0.4622 (3) | 0.4054 (2) | 0.41373 (6) | 0.0550 (4) | |
H4 | 0.4127 | 0.4779 | 0.3923 | 0.066* | |
C5 | 0.6306 (2) | 0.3332 (2) | 0.40424 (6) | 0.0526 (4) | |
H5 | 0.6909 | 0.3557 | 0.3759 | 0.063* | |
C6 | 0.7133 (2) | 0.22707 (19) | 0.43592 (5) | 0.0485 (4) | |
C7 | 0.8888 (2) | 0.1438 (2) | 0.42611 (6) | 0.0538 (4) | |
H7 | 0.9696 | 0.1252 | 0.4519 | 0.065* | |
C8 | 0.9433 (2) | 0.0922 (2) | 0.38397 (6) | 0.0533 (4) | |
C9 | 0.8334 (2) | 0.09022 (18) | 0.33887 (6) | 0.0496 (4) | |
C10 | 0.6604 (2) | 0.0123 (2) | 0.33830 (6) | 0.0544 (4) | |
H10 | 0.6183 | −0.0345 | 0.3661 | 0.065* | |
C11 | 0.5508 (3) | 0.0032 (2) | 0.29757 (6) | 0.0595 (5) | |
H11 | 0.4355 | −0.0484 | 0.2977 | 0.071* | |
C12 | 0.6152 (3) | 0.0721 (2) | 0.25666 (6) | 0.0600 (5) | |
C13 | 0.7851 (3) | 0.1492 (2) | 0.25508 (6) | 0.0621 (5) | |
H13 | 0.8268 | 0.1941 | 0.2270 | 0.075* | |
C14 | 0.8908 (3) | 0.15779 (19) | 0.29608 (6) | 0.0546 (4) | |
C15 | 0.1127 (3) | 0.5435 (3) | 0.43490 (9) | 0.0773 (6) | |
H15A | 0.1939 | 0.6321 | 0.4308 | 0.116* | |
H15B | −0.0055 | 0.5777 | 0.4474 | 0.116* | |
H15C | 0.0916 | 0.4931 | 0.4047 | 0.116* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0840 (10) | 0.0847 (10) | 0.0890 (11) | 0.0046 (8) | 0.0348 (8) | 0.0213 (8) |
O2 | 0.1245 (14) | 0.1098 (13) | 0.0486 (8) | 0.0069 (11) | 0.0149 (8) | 0.0170 (8) |
O3 | 0.0861 (11) | 0.1192 (15) | 0.1100 (13) | 0.0423 (10) | 0.0247 (10) | −0.0232 (11) |
O4 | 0.0688 (9) | 0.1294 (16) | 0.1133 (14) | 0.0377 (10) | −0.0148 (10) | 0.0005 (12) |
O5 | 0.1076 (14) | 0.155 (2) | 0.0931 (13) | −0.0649 (14) | 0.0158 (11) | −0.0068 (13) |
O6 | 0.1398 (19) | 0.162 (2) | 0.1027 (14) | −0.0639 (16) | 0.0551 (14) | 0.0205 (14) |
O7 | 0.170 (2) | 0.1087 (15) | 0.0912 (13) | −0.0568 (15) | −0.0463 (13) | 0.0033 (11) |
O8 | 0.187 (2) | 0.0796 (11) | 0.0495 (8) | −0.0126 (12) | −0.0097 (10) | 0.0004 (7) |
O9 | 0.0733 (8) | 0.0713 (9) | 0.0689 (8) | 0.0283 (7) | 0.0235 (6) | 0.0139 (6) |
N1 | 0.0851 (11) | 0.0508 (8) | 0.0514 (9) | 0.0146 (7) | 0.0211 (8) | 0.0070 (6) |
N2 | 0.0569 (9) | 0.0753 (11) | 0.0870 (12) | 0.0183 (8) | 0.0136 (9) | 0.0052 (9) |
N3 | 0.0797 (11) | 0.0624 (10) | 0.0798 (12) | −0.0113 (8) | 0.0280 (9) | 0.0101 (9) |
N4 | 0.1380 (18) | 0.0552 (9) | 0.0553 (10) | −0.0070 (11) | −0.0105 (10) | −0.0090 (8) |
C1 | 0.0642 (10) | 0.0477 (8) | 0.0384 (8) | 0.0075 (7) | 0.0009 (6) | 0.0016 (6) |
C2 | 0.0651 (10) | 0.0451 (8) | 0.0423 (8) | 0.0056 (7) | 0.0113 (7) | 0.0009 (6) |
C3 | 0.0615 (9) | 0.0469 (8) | 0.0490 (9) | 0.0116 (7) | 0.0091 (7) | 0.0001 (7) |
C4 | 0.0676 (10) | 0.0526 (9) | 0.0448 (8) | 0.0144 (8) | 0.0031 (7) | 0.0075 (7) |
C5 | 0.0617 (9) | 0.0552 (9) | 0.0413 (8) | 0.0068 (7) | 0.0100 (7) | 0.0049 (7) |
C6 | 0.0527 (8) | 0.0502 (9) | 0.0427 (8) | 0.0053 (7) | 0.0029 (6) | 0.0000 (6) |
C7 | 0.0520 (9) | 0.0584 (10) | 0.0510 (9) | 0.0060 (7) | 0.0011 (7) | 0.0075 (7) |
C8 | 0.0461 (8) | 0.0539 (9) | 0.0602 (9) | 0.0079 (7) | 0.0093 (7) | 0.0066 (7) |
C9 | 0.0526 (8) | 0.0464 (8) | 0.0504 (9) | 0.0055 (6) | 0.0170 (7) | 0.0005 (6) |
C10 | 0.0584 (9) | 0.0569 (10) | 0.0483 (8) | −0.0025 (7) | 0.0165 (7) | 0.0037 (7) |
C11 | 0.0657 (10) | 0.0550 (10) | 0.0580 (10) | −0.0045 (8) | 0.0082 (8) | −0.0033 (8) |
C12 | 0.0889 (13) | 0.0451 (8) | 0.0459 (9) | 0.0020 (8) | 0.0038 (8) | −0.0068 (7) |
C13 | 0.0943 (14) | 0.0436 (9) | 0.0492 (9) | 0.0002 (9) | 0.0227 (9) | 0.0013 (7) |
C14 | 0.0656 (10) | 0.0436 (8) | 0.0551 (9) | −0.0004 (7) | 0.0215 (8) | 0.0018 (7) |
C15 | 0.0729 (12) | 0.0743 (13) | 0.0850 (14) | 0.0304 (10) | 0.0115 (10) | 0.0122 (11) |
Geometric parameters (Å, º) top
O1—N1 | 1.226 (3) | C4—H4 | 0.9300 |
O2—N1 | 1.217 (2) | C5—C6 | 1.395 (2) |
O3—N2 | 1.223 (3) | C5—H5 | 0.9300 |
O4—N2 | 1.220 (3) | C6—C7 | 1.464 (2) |
O5—N3 | 1.184 (3) | C7—C8 | 1.327 (2) |
O6—N3 | 1.210 (2) | C7—H7 | 0.9300 |
O7—N4 | 1.210 (3) | C8—C9 | 1.478 (3) |
O8—N4 | 1.213 (3) | C9—C10 | 1.397 (2) |
O9—C3 | 1.348 (2) | C9—C14 | 1.400 (2) |
O9—C15 | 1.430 (2) | C10—C11 | 1.376 (3) |
N1—C2 | 1.460 (2) | C10—H10 | 0.9300 |
N2—C8 | 1.476 (2) | C11—C12 | 1.376 (3) |
N3—C14 | 1.474 (3) | C11—H11 | 0.9300 |
N4—C12 | 1.469 (3) | C12—C13 | 1.375 (3) |
C1—C2 | 1.377 (2) | C13—C14 | 1.367 (3) |
C1—C6 | 1.393 (2) | C13—H13 | 0.9300 |
C1—H1 | 0.9300 | C15—H15A | 0.9600 |
C2—C3 | 1.396 (2) | C15—H15B | 0.9600 |
C3—C4 | 1.390 (2) | C15—H15C | 0.9600 |
C4—C5 | 1.374 (2) | | |
| | | |
C3—O9—C15 | 117.88 (14) | C8—C7—C6 | 126.2 (2) |
O2—N1—O1 | 123.87 (17) | C8—C7—H7 | 116.9 |
O2—N1—C2 | 117.28 (18) | C6—C7—H7 | 116.9 |
O1—N1—C2 | 118.80 (17) | C7—C8—N2 | 116.70 (16) |
O4—N2—O3 | 124.22 (18) | C7—C8—C9 | 127.8 (2) |
O4—N2—C8 | 119.51 (18) | N2—C8—C9 | 114.93 (15) |
O3—N2—C8 | 116.27 (18) | C10—C9—C14 | 117.00 (16) |
O5—N3—O6 | 122.1 (2) | C10—C9—C8 | 117.87 (14) |
O5—N3—C14 | 120.36 (17) | C14—C9—C8 | 125.12 (16) |
O6—N3—C14 | 117.5 (2) | C11—C10—C9 | 121.47 (15) |
O7—N4—O8 | 123.6 (2) | C11—C10—H10 | 119.3 |
O7—N4—C12 | 118.05 (18) | C9—C10—H10 | 119.3 |
O8—N4—C12 | 118.3 (2) | C12—C11—C10 | 118.69 (17) |
C2—C1—C6 | 119.92 (15) | C12—C11—H11 | 120.7 |
C2—C1—H1 | 120.0 | C10—C11—H11 | 120.7 |
C6—C1—H1 | 120.0 | C11—C12—C13 | 122.31 (18) |
C1—C2—C3 | 122.36 (15) | C11—C12—N4 | 119.09 (19) |
C1—C2—N1 | 117.79 (15) | C13—C12—N4 | 118.59 (17) |
C3—C2—N1 | 119.84 (15) | C14—C13—C12 | 117.92 (15) |
O9—C3—C4 | 125.07 (15) | C14—C13—H13 | 121.0 |
O9—C3—C2 | 117.70 (15) | C12—C13—H13 | 121.0 |
C4—C3—C2 | 117.18 (15) | C13—C14—C9 | 122.60 (17) |
C5—C4—C3 | 120.76 (15) | C13—C14—N3 | 117.10 (15) |
C5—C4—H4 | 119.6 | C9—C14—N3 | 120.31 (17) |
C3—C4—H4 | 119.6 | O9—C15—H15A | 109.5 |
C4—C5—C6 | 121.81 (15) | O9—C15—H15B | 109.5 |
C4—C5—H5 | 119.1 | H15A—C15—H15B | 109.5 |
C6—C5—H5 | 119.1 | O9—C15—H15C | 109.5 |
C1—C6—C5 | 117.77 (15) | H15A—C15—H15C | 109.5 |
C1—C6—C7 | 119.04 (14) | H15B—C15—H15C | 109.5 |
C5—C6—C7 | 123.2 (1) | | |
| | | |
C6—C1—C2—C3 | −3.8 (3) | O3—N2—C8—C9 | −7.4 (3) |
C6—C1—C2—N1 | 175.10 (16) | C7—C8—C9—C10 | −56.5 (2) |
O2—N1—C2—C1 | 46.2 (2) | N2—C8—C9—C10 | 114.06 (18) |
O1—N1—C2—C1 | −131.25 (18) | C7—C8—C9—C14 | 124.9 (2) |
O2—N1—C2—C3 | −134.81 (19) | N2—C8—C9—C14 | −64.5 (2) |
O1—N1—C2—C3 | 47.7 (2) | C14—C9—C10—C11 | −0.4 (2) |
C15—O9—C3—C4 | 2.0 (3) | C8—C9—C10—C11 | −179.11 (15) |
C15—O9—C3—C2 | 179.5 (2) | C9—C10—C11—C12 | 0.4 (3) |
C1—C2—C3—O9 | −177.61 (16) | C10—C11—C12—C13 | 0.2 (3) |
N1—C2—C3—O9 | 3.5 (3) | C10—C11—C12—N4 | 178.95 (16) |
C1—C2—C3—C4 | 0.0 (3) | O7—N4—C12—C11 | −9.3 (3) |
N1—C2—C3—C4 | −178.91 (16) | O8—N4—C12—C11 | 171.3 (2) |
O9—C3—C4—C5 | −179.76 (17) | O7—N4—C12—C13 | 169.6 (2) |
C2—C3—C4—C5 | 2.8 (3) | O8—N4—C12—C13 | −9.9 (3) |
C3—C4—C5—C6 | −1.9 (3) | C11—C12—C13—C14 | −0.7 (3) |
C2—C1—C6—C5 | 4.7 (2) | N4—C12—C13—C14 | −179.47 (16) |
C2—C1—C6—C7 | −174.90 (15) | C12—C13—C14—C9 | 0.7 (3) |
C4—C5—C6—C1 | −2.0 (3) | C12—C13—C14—N3 | −179.02 (16) |
C4—C5—C6—C7 | 177.63 (17) | C10—C9—C14—C13 | −0.2 (2) |
C1—C6—C7—C8 | 144.2 (2) | C8—C9—C14—C13 | 178.46 (15) |
C5—C6—C7—C8 | −35.4 (3) | C10—C9—C14—N3 | 179.53 (15) |
C6—C7—C8—N2 | −177.96 (16) | C8—C9—C14—N3 | −1.9 (2) |
C6—C7—C8—C9 | −7.5 (3) | O5—N3—C14—C13 | 160.0 (2) |
O4—N2—C8—C7 | −14.9 (3) | O6—N3—C14—C13 | −19.8 (3) |
O3—N2—C8—C7 | 164.2 (2) | O5—N3—C14—C9 | −19.7 (3) |
O4—N2—C8—C9 | 173.47 (19) | O6—N3—C14—C9 | 160.5 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O8i | 0.93 | 2.43 | 3.266 (2) | 149 |
C15—H15B···O1ii | 0.96 | 2.50 | 3.321 (3) | 144 |
C10—H10···O2iii | 0.93 | 2.52 | 3.426 (3) | 164 |
C11—H11···O3iv | 0.93 | 2.46 | 3.226 (3) | 140 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x, −y+1, −z+1; (iii) −x+1, −y, −z+1; (iv) x−1, y, z. |
Experimental details
Crystal data |
Chemical formula | C15H10N4O9 |
Mr | 390.27 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 7.096 (4), 8.550 (3), 28.101 (5) |
β (°) | 90.87 (3) |
V (Å3) | 1704.7 (12) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 1.12 |
Crystal size (mm) | 0.6 × 0.40 × 0.35 |
|
Data collection |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6505, 3105, 2787 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.601 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.051, 0.153, 1.05 |
No. of reflections | 3105 |
No. of parameters | 255 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.40, −0.21 |
Selected geometric parameters (Å, º) topO1—N1 | 1.226 (3) | O8—N4 | 1.213 (3) |
O2—N1 | 1.217 (2) | O9—C3 | 1.348 (2) |
O3—N2 | 1.223 (3) | O9—C15 | 1.430 (2) |
O4—N2 | 1.220 (3) | C6—C7 | 1.464 (2) |
O5—N3 | 1.184 (3) | C7—C8 | 1.327 (2) |
O6—N3 | 1.210 (2) | C8—C9 | 1.478 (3) |
O7—N4 | 1.210 (3) | | |
| | | |
C5—C6—C7 | 123.2 (1) | C7—C8—C9 | 127.8 (2) |
C8—C7—C6 | 126.2 (2) | | |
| | | |
C15—O9—C3—C4 | 2.0 (3) | C1—C6—C7—C8 | 144.2 (2) |
C2—C3—C4—C5 | 2.8 (3) | C6—C7—C8—C9 | −7.5 (3) |
C3—C4—C5—C6 | −1.9 (3) | O4—N2—C8—C7 | −14.9 (3) |
C2—C1—C6—C5 | 4.7 (2) | C7—C8—C9—C10 | −56.5 (2) |
C4—C5—C6—C1 | −2.0 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O8i | 0.93 | 2.43 | 3.266 (2) | 149 |
C15—H15B···O1ii | 0.96 | 2.50 | 3.321 (3) | 144 |
C10—H10···O2iii | 0.93 | 2.52 | 3.426 (3) | 164 |
C11—H11···O3iv | 0.93 | 2.46 | 3.226 (3) | 140 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x, −y+1, −z+1; (iii) −x+1, −y, −z+1; (iv) x−1, y, z. |
Nitro compounds are well known for their uses as explosives, dye intermediates and battery cathodes (Sivasamy et al., 1988; Renuka et al., 2001)·These compounds are excellent precursors for aromatic amines and medicinally important compounds. Some synthetic nitro compounds are used in perfumery. m-Dinitrobenzene has been found to function as an organic cathode material in batteries. The new synthetic methodologies for polynitro compounds are of much importance in the chemical industry and defence research studies. α-Nitrostilbenes are excellent precursors for biologically active β-phenylethylamines and Michael acceptors (Robertson, 1960; Flintoft et al., 1999). A survey of the literature shows that only a few styrenes undergo direct nitration to give β-nitrostyrenes, while there are no reports of side-chain nitration of stilbenes. Against this background, and in order to obtain detailed information on the molecular conformation of nitrostilbenes in the solid state, X-ray studies of the title compound, (I), have been carried out and the results are presented here.
Fig. 1 shows a ZORTEP plot (Zsolnai, 1997) of (I) with the atom-numbering scheme. The phenyl rings are twisted out of the ethylenic bond plane as defined by the torsion angles C1—C6—C7═C8 and C7═C8—C9—C14. Therefore the phenyl rings are inclined to each other; the dihedral angle formed between their mean plane is 57.4 (1)° as a result of the C—H···O intermolecular interactions involving the phenyl H atoms. The bond length C7═C8 is typical of the reported ethylene C═C bond length [1.318 (5)–1.326 (3) Å (Finder et al., 1974; Bernstein,1975)] and of a non-conjugated double bond. The N═O distances of the nitro groups, except N3═O5, are comparable to the literature values Car—NO2 = 1.217 (11) Å (Allen et al., 1987) and also agree with the average value of 1.216 (7) Å reported by Jeyakanthan (2000). Comparing the C7═C8 distance with the expected 1.317 (13) value for a localized double bond (Allen et al., 1987) it seems that there is a tendency to have some lengthening that is indicative of some π conjugation of the two phenyls through the central ethene bridge and agrees with the shortening of the two C6—C7 and C8—C9 bonds whose average distance, 1.471 (4), coincides with the value 1.470 (15) given by Allen et al. (1987) for a Car—Csp2conjugate bond. Similar values have been observed for (Z)-5-(methoxymethyl)-3-[4-phenylethenyl)phenyl]-2-oxazolidinone (Durant et al., 1982).
Because of the high electron-withdrawing capacity of the two NO2 groups, the dinitrophenyl ring causes high polarization of the olefinic double bond and enhanced electron density on the α carbon to the dinitrophenyl group. This mechanism is responsible for nitration on that carbon only. The valence angles between the olefinic double bond and the two phenyl rings, C7═C8—C9 = 127.8 (2) and C6—C7═C8 = 126.2 (2)°, are almost equal and are larger than 120°, which indicates steric repulsion between the two aromatic rings that are in a cis configuration. These values are comparable to the reported values of other cis stilbenes (Tinant et al., 1989, 1983). The methoxy group has an almost coplanar orientation with respect to atoms C2 and C4, as is evident from the torsion angles C2—C3—O9—C15 and C4—C3—O9—C15, respectively.
Nitro group O4═N2═O3 has an almost coplanar orientation with respect to the side chain C6—C7═C8—C9, as is evident from the torsion angles O3═N2—C8—C7 and O4═N2—C8—C7, respectively. The dihedral angle between C9,···,C14 and O5═N3═O6 is 19.9 (1)° and between C1,···,C6 and O1═N1═O2 is 48.1 (1)°. These nitro groups are twisted out of the plane passing through the phenyl rings to which they are attached, whereas the nitro group O7═N4═O8 is nearly coplanar with C9,···,C14 as the dihedral angle is 9.5 (1)°. The twistings of the nitro groups are evidenced by the following short H···O contacts: H1···O2 2.60, H7···O4 2.32, H13···O6 2.41, H13···O8 2.44, H11—O7 2.44 Å. Atoms C7 and C8 deviate from the planes of the respective phenyl rings by 0.094 (2) and 0.025 (2) Å, respectively. The inter torsion angle between the phenyl rings C6—C7═C8—C9 = −7.5 (3)° also indicates a cis geometry between them.
In addition to the van der Waals interactions the crystal packing is stabilized by C—H···O interactions (Table 2). The C4—H4···O8 hydrogen bond forms a graph-set chain C(12) (Bernstein et al., 1995) in a zigzag manner represented by C4—H4···O8═N4—C12—C13—C14—C9—C8═C7—C6—C5 running along the [010] direction (Fig 2).