organic compounds
2,2′-Dimethoxy-6,6′-dinitrobiphenyl
aCollege of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022, People's Republic of China
*Correspondence e-mail: lyhxxjbm@126.com
In the title compound, C14H12N2O6, the half molecule in the of the cell is completed by a crystallographic twofold rotation axis, and the two benzene rings of the complete molecule make a dihedral angle of 60.5 (3)°. Furthermore, intermolecular weak C—H⋯O hydrogen bonds link adjacent molecules, forming a two-dimensional sheet. These sheets are stablized by face-to-face weak π–π contacts [centroid–centroid distance = 3.682 (1) Å] between the nearly parallel [dihedral angle = 0.12 (7)°] benzene rings of the neighboring molecules, resulting in a three-dimensional network.
Related literature
For the synthesis of the title compound, see: Chen et al. (2001). For using chiral ligands with C2 symmetry, see: Jiang et al. (2001); García et al. (2002). For synthetic methods for chiral compounds, see: Brunel (2005); Kočovský et al. (2003). For related biphenyl structures, see: Fischer et al. (2007). For related structural data see: Yang et al. (2005).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2004); cell SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 and PLATON.
Supporting information
10.1107/S1600536809033790/si2193sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809033790/si2193Isup2.hkl
The title compound was synthesized by a reported method (Chen, et al. 2001),namely, a mixture of 2-iodo-3-nitroanisol (14 g, 0.05 mol) and activated copper brone (9.5 g, 0.15 mol), 50 ml of dimethylformamide was stirried at 140°C for 4 h under nitrogen atmosphere. Yellow crystals suitable for X-ray diffraction study were obtained from a solution in acetic ester.
All of the non-hydrogen atoms were refined anisotropically. The hydrogen atoms were assigned with common isotropic displacement factors Uiso(H) = 1.2 times Ueq(C,N) and 1.5 times Ueq(O), respectively, and included in the final
by using geometrical restraints, with C–H distances of 0.93 Å.Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).Fig. 1. ORTEP drawing (30% probability displacement ellipsoids) of a single molecule of the title compound. | |
Fig. 2. three-dimensional structures of the title compound. |
C14H12N2O6 | F(000) = 632 |
Mr = 304.26 | Dx = 1.441 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 1790 reflections |
a = 18.236 (3) Å | θ = 2.5–25.7° |
b = 7.7826 (12) Å | µ = 0.12 mm−1 |
c = 10.9079 (17) Å | T = 294 K |
β = 115.089 (2)° | Block, yellow |
V = 1402.0 (4) Å3 | 0.30 × 0.18 × 0.18 mm |
Z = 4 |
Bruker APEXII CCD area-detector diffractometer | 1298 independent reflections |
Radiation source: fine-focus sealed tube | 1009 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
ϕ and ω scans | θmax = 25.5°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −22→22 |
Tmin = 0.966, Tmax = 0.979 | k = −9→9 |
5102 measured reflections | l = −13→13 |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.097 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0401P)2 + 0.8036P] where P = (Fo2 + 2Fc2)/3 |
1298 reflections | (Δ/σ)max < 0.001 |
101 parameters | Δρmax = 0.14 e Å−3 |
0 restraints | Δρmin = −0.13 e Å−3 |
C14H12N2O6 | V = 1402.0 (4) Å3 |
Mr = 304.26 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 18.236 (3) Å | µ = 0.12 mm−1 |
b = 7.7826 (12) Å | T = 294 K |
c = 10.9079 (17) Å | 0.30 × 0.18 × 0.18 mm |
β = 115.089 (2)° |
Bruker APEXII CCD area-detector diffractometer | 1298 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1009 reflections with I > 2σ(I) |
Tmin = 0.966, Tmax = 0.979 | Rint = 0.019 |
5102 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.097 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.14 e Å−3 |
1298 reflections | Δρmin = −0.13 e Å−3 |
101 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.49134 (9) | 0.22562 (19) | 0.67636 (14) | 0.0387 (4) | |
C2 | 0.54245 (9) | 0.2962 (2) | 0.62577 (15) | 0.0434 (4) | |
C3 | 0.52777 (12) | 0.2896 (2) | 0.49065 (17) | 0.0546 (5) | |
H3 | 0.5639 | 0.3378 | 0.4607 | 0.066* | |
C4 | 0.45847 (12) | 0.2102 (2) | 0.40223 (17) | 0.0588 (5) | |
H4 | 0.4471 | 0.2058 | 0.3107 | 0.071* | |
C5 | 0.40569 (11) | 0.1370 (2) | 0.44656 (16) | 0.0540 (5) | |
H5 | 0.3589 | 0.0835 | 0.3852 | 0.065* | |
C6 | 0.42203 (9) | 0.1426 (2) | 0.58296 (15) | 0.0444 (4) | |
C7 | 0.30000 (13) | −0.0071 (4) | 0.5464 (2) | 0.0944 (8) | |
H7A | 0.2673 | 0.0767 | 0.4817 | 0.142* | |
H7B | 0.2716 | −0.0485 | 0.5971 | 0.142* | |
H7C | 0.3110 | −0.1012 | 0.4998 | 0.142* | |
N1 | 0.61559 (9) | 0.3880 (2) | 0.71661 (15) | 0.0557 (4) | |
O1 | 0.37432 (7) | 0.06986 (18) | 0.63620 (11) | 0.0594 (4) | |
O2 | 0.61327 (8) | 0.47507 (17) | 0.80791 (13) | 0.0615 (4) | |
O3 | 0.67594 (9) | 0.3739 (3) | 0.69543 (17) | 0.0967 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0399 (8) | 0.0425 (8) | 0.0345 (8) | 0.0057 (6) | 0.0166 (7) | 0.0011 (6) |
C2 | 0.0464 (9) | 0.0454 (9) | 0.0426 (8) | 0.0044 (7) | 0.0229 (7) | 0.0023 (7) |
C3 | 0.0722 (12) | 0.0549 (10) | 0.0508 (10) | 0.0071 (9) | 0.0399 (9) | 0.0053 (8) |
C4 | 0.0853 (14) | 0.0566 (11) | 0.0369 (8) | 0.0117 (10) | 0.0283 (10) | 0.0036 (8) |
C5 | 0.0610 (11) | 0.0545 (10) | 0.0372 (8) | 0.0046 (9) | 0.0119 (8) | −0.0031 (8) |
C6 | 0.0452 (9) | 0.0473 (9) | 0.0388 (8) | 0.0033 (7) | 0.0159 (7) | 0.0004 (7) |
C7 | 0.0600 (13) | 0.142 (2) | 0.0750 (14) | −0.0445 (14) | 0.0224 (12) | −0.0253 (15) |
N1 | 0.0500 (8) | 0.0679 (10) | 0.0571 (9) | −0.0031 (7) | 0.0302 (7) | 0.0073 (8) |
O1 | 0.0473 (7) | 0.0794 (9) | 0.0474 (7) | −0.0193 (6) | 0.0162 (6) | −0.0058 (6) |
O2 | 0.0612 (8) | 0.0665 (8) | 0.0570 (7) | −0.0133 (6) | 0.0253 (6) | −0.0081 (7) |
O3 | 0.0604 (9) | 0.1503 (16) | 0.0999 (12) | −0.0197 (10) | 0.0538 (9) | −0.0120 (11) |
C1—C2 | 1.383 (2) | C5—C6 | 1.389 (2) |
C1—C6 | 1.400 (2) | C5—H5 | 0.9300 |
C1—C1i | 1.500 (3) | C6—O1 | 1.3576 (19) |
C2—C3 | 1.383 (2) | C7—O1 | 1.424 (2) |
C2—N1 | 1.466 (2) | C7—H7A | 0.9600 |
C3—C4 | 1.370 (3) | C7—H7B | 0.9600 |
C3—H3 | 0.9300 | C7—H7C | 0.9600 |
C4—C5 | 1.371 (3) | N1—O2 | 1.2200 (18) |
C4—H4 | 0.9300 | N1—O3 | 1.2217 (18) |
C2—C1—C6 | 116.51 (13) | C6—C5—H5 | 120.0 |
C2—C1—C1i | 123.77 (15) | O1—C6—C5 | 124.06 (15) |
C6—C1—C1i | 119.63 (14) | O1—C6—C1 | 115.19 (13) |
C1—C2—C3 | 123.51 (15) | C5—C6—C1 | 120.75 (15) |
C1—C2—N1 | 119.86 (13) | O1—C7—H7A | 109.5 |
C3—C2—N1 | 116.60 (14) | O1—C7—H7B | 109.5 |
C4—C3—C2 | 118.11 (16) | H7A—C7—H7B | 109.5 |
C4—C3—H3 | 120.9 | O1—C7—H7C | 109.5 |
C2—C3—H3 | 120.9 | H7A—C7—H7C | 109.5 |
C3—C4—C5 | 121.01 (15) | H7B—C7—H7C | 109.5 |
C3—C4—H4 | 119.5 | O2—N1—O3 | 123.39 (16) |
C5—C4—H4 | 119.5 | O2—N1—C2 | 119.06 (13) |
C4—C5—C6 | 120.08 (17) | O3—N1—C2 | 117.55 (16) |
C4—C5—H5 | 120.0 | C6—O1—C7 | 118.46 (14) |
C6—C1—C2—C3 | 0.7 (2) | C2—C1—C6—O1 | 178.01 (14) |
C1i—C1—C2—C3 | 177.26 (13) | C1i—C1—C6—O1 | 1.26 (19) |
C6—C1—C2—N1 | 178.92 (14) | C2—C1—C6—C5 | −1.6 (2) |
C1i—C1—C2—N1 | −4.5 (2) | C1i—C1—C6—C5 | −178.36 (13) |
C1—C2—C3—C4 | 0.6 (3) | C1—C2—N1—O2 | −36.5 (2) |
N1—C2—C3—C4 | −177.73 (16) | C3—C2—N1—O2 | 141.90 (16) |
C2—C3—C4—C5 | −0.9 (3) | C1—C2—N1—O3 | 144.16 (17) |
C3—C4—C5—C6 | 0.0 (3) | C3—C2—N1—O3 | −37.5 (2) |
C4—C5—C6—O1 | −178.25 (16) | C5—C6—O1—C7 | −4.5 (3) |
C4—C5—C6—C1 | 1.3 (3) | C1—C6—O1—C7 | 175.90 (18) |
Symmetry code: (i) −x+1, y, −z+3/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7B···O3ii | 0.96 | 2.48 | 3.426 (3) | 169 |
Symmetry code: (ii) x−1/2, y−1/2, z. |
Experimental details
Crystal data | |
Chemical formula | C14H12N2O6 |
Mr | 304.26 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 294 |
a, b, c (Å) | 18.236 (3), 7.7826 (12), 10.9079 (17) |
β (°) | 115.089 (2) |
V (Å3) | 1402.0 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.12 |
Crystal size (mm) | 0.30 × 0.18 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.966, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5102, 1298, 1009 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.097, 1.03 |
No. of reflections | 1298 |
No. of parameters | 101 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.13 |
Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7B···O3i | 0.96 | 2.48 | 3.426 (3) | 169 |
Symmetry code: (i) x−1/2, y−1/2, z. |
Acknowledgements
This work was supported by the Youth Foundation of Luoyang Normal University (No. 10000409).
References
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A large number of chiral compounds with C2-symmetry are widely used as chiral auxiliaries and ligands in asymmetric synthesis and have shown high stereocontrol properties in a wide range of asymmetric transformations (Jiang et al. 2001; García et al. 2002). Design and synthesis of such compounds play a very important role in the development of highly enantioselective asymmetric reactions. Thus, it is not surprising that a lot of methods have been developed to obtain these chiral compounds (Brunel 2005; Kočovský et al. 2003). In this paper, we report the synthesis and crystal structure of the title compound with C2-symmetry.
A view of the molecular structure of the title compound is given in Fig.1. All bond lengths and angles are in the expected range and in good agreement with those reported previously (Yang et al. 2005). The dihedral angle between two benzene rings is 60.5 (3)°, which is considerable larger than those found in other biphenyls (Fischer et al. 2007), possibly due to the concomitant effects of the steric hindrance of adjacent methoxy and nitro groups.
In the crystal structure, each molecule is connected by four adjacent molecules through intermolecular C—H···O hydrogen bonds (Table 1), between methoxy groups and O atoms of the adjacent nitro groups, leading to the formation of a two-dimensional sheet in the ac plane. The sheets are further connected into a three-dimensional network(Fig.2) by the face-to-face weak π–π contacts between nearly parallel benzene rings of the neighboring title molecules. The Cg1···Cg1iii distance is 3.6823 (11) Å, the perpendicular distance between the rings is 3.410 Å, and the slippage between the rings is 1.389 Å. Cg1 is the centroid of the benzene ring C1 - C6, the symmetry code iii = 1 - x, -y, 1 - z.