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Acta Crystallogr Sect E Struct Rep Online. 2008 January 1; 64(Pt 1): o153.
Published online 2007 December 6. doi:  10.1107/S1600536807063581
PMCID: PMC2915221

(4,6-Dibromo-m-phenyl­enedimethyl­idyne) tetra­acetate

Abstract

The title mol­ecule, C16H16Br2O8, lies on a crystallographic twofold axis. Weak intra­molecular C—H(...)O hydrogen bonds may, in part, control the conformation of the mol­ecule. In the crystal structure, mol­ecules are connected into a two-dimensional network via weak inter­molecular C—H(...)O hydrogen bonds.

Related literature

For related literature, see: Allen et al. (1987 [triangle]); Mitchell et al. (1995 [triangle]).

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Object name is e-64-0o153-scheme1.jpg

Experimental

Crystal data

  • C16H16Br2O8
  • M r = 496.09
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-64-0o153-efi2.jpg
  • a = 20.639 (4) Å
  • b = 10.150 (2) Å
  • c = 9.0880 (18) Å
  • V = 1903.8 (6) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 4.30 mm−1
  • T = 298 (2) K
  • 0.40 × 0.30 × 0.20 mm

Data collection

  • Enraf–Nonius CAD-4 diffractometer
  • Absorption correction: ψ scan (North et al., 1968 [triangle]) T min = 0.278, T max = 0.480 (expected range = 0.245–0.423)
  • 3687 measured reflections
  • 1877 independent reflections
  • 805 reflections with I > 2σ(I)
  • R int = 0.054
  • 3 standard reflections every 200 reflections intensity decay: none

Refinement

  • R[F 2 > 2σ(F 2)] = 0.067
  • wR(F 2) = 0.130
  • S = 0.96
  • 1877 reflections
  • 107 parameters
  • 29 restraints
  • H-atom parameters constrained
  • Δρmax = 0.58 e Å−3
  • Δρmin = −0.49 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1985 [triangle]); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 [triangle]); molecular graphics: SHELXTL (Bruker, 2000 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807063581/lh2578sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807063581/lh2578Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

supplementary crystallographic information

Comment

The molecular structure of the title compound is shown in Fig. 1. The bond lengths and angles are within normal ranges (Allen et al., 1987).

The asymmetric unit contains one half-molecule; the full molecule being generated by a crystallographic twofold rotation axis. Weak intramolecular C—H···O hydrogen bonds may, in part, control the conformation of the molecule. In the crystal structure, molecules are connected into a two-dimensional network via weak intermolecular C—H···O hydrogen bonds. (Fig. 2).

Experimental

The title compound was prepared by a previously reported method (Mitchell et al., 1995).

The crystals of the title compound, were obtained by dissolving (I) (2.00 g, 4.03 mmol) into acetone (50 ml), and evaporating the solvent slowly at room temperature for about 3 d.

Refinement

H atoms were positioned geometrically, with C—H = 0.93 - 0.98Å and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.5 for methyl H and x = 1.2 for all other H atoms.

Figures

Fig. 1.
The molecular structure, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level. Hydrogen bonds are shown by dashed lines. [Symmetry code: (A) -x + 1, y, -z + 1/2.]
Fig. 2.
The packing of the title compound with C—H···O hydrogen bonds are shown by dashed lines.

Crystal data

C16H16Br2O8F000 = 984
Mr = 496.09Dx = 1.731 Mg m3
Orthorhombic, PbcnMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2n 2abCell parameters from 25 reflections
a = 20.639 (4) Åθ = 10–14º
b = 10.150 (2) ŵ = 4.30 mm1
c = 9.0880 (18) ÅT = 298 (2) K
V = 1903.8 (6) Å3Plate, colourless
Z = 40.40 × 0.30 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometerRint = 0.054
Radiation source: fine-focus sealed tubeθmax = 26.0º
Monochromator: graphiteθmin = 2.0º
T = 298(2) Kh = 0→25
ω/2θ scansk = 0→12
Absorption correction: ψ scan(North et al., 1968)l = 0→11
Tmin = 0.278, Tmax = 0.4803 standard reflections
3687 measured reflections every 200 reflections
1877 independent reflections intensity decay: none
805 reflections with I > 2σ(I)

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.067H-atom parameters constrained
wR(F2) = 0.130  w = 1/[σ2(Fo2) + (0.02P)2 + 0.0P] where P = (Fo2 + 2Fc2)/3
S = 0.96(Δ/σ)max = 0.001
1877 reflectionsΔρmax = 0.58 e Å3
107 parametersΔρmin = −0.49 e Å3
29 restraintsExtinction correction: none
Primary atom site location: structure-invariant direct methods

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 (Å2)

xyzUiso*/Ueq
Br0.61944 (4)0.39329 (6)0.10603 (9)0.0671 (3)
O10.6622 (2)0.6733 (4)0.2433 (6)0.0456 (11)
O20.7386 (3)0.6717 (7)0.0680 (7)0.0852 (19)
O30.6065 (2)0.8406 (5)0.1438 (5)0.049
O40.5702 (3)0.8387 (5)−0.0882 (6)0.0750 (17)
C10.50000.4229 (8)0.25000.042 (2)
H1A0.50000.33130.25000.051*
C20.5520 (3)0.4888 (6)0.1917 (7)0.0390 (16)
C30.5535 (3)0.6316 (6)0.1962 (7)0.0414 (17)
C40.50000.6958 (9)0.25000.037 (2)
H4A0.50000.78740.25000.044*
C50.6135 (3)0.6973 (7)0.1474 (7)0.041
H5A0.62560.66520.04940.049*
C60.7244 (4)0.6543 (8)0.1961 (9)0.052 (2)
C70.7671 (4)0.6004 (9)0.3066 (9)0.084 (3)
H7A0.80980.59060.26610.126*
H7B0.75130.51590.33750.126*
H7C0.76880.65880.38960.126*
C80.5877 (3)0.8970 (7)0.0164 (10)0.063 (2)
C90.5899 (4)1.0491 (6)0.0331 (9)0.060 (2)
H9A0.57611.0896−0.05710.090*
H9B0.63341.07620.05520.090*
H9C0.56161.07570.11160.090*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br0.0785 (5)0.0252 (4)0.0977 (6)0.0028 (4)0.0283 (5)−0.0106 (5)
O10.055 (3)0.033 (2)0.049 (3)0.001 (2)−0.007 (2)−0.009 (3)
O20.064 (4)0.107 (5)0.084 (4)−0.006 (4)0.024 (3)−0.001 (4)
O30.0490.0490.0490.0000.0000.000
O40.095 (4)0.051 (3)0.080 (4)−0.008 (3)−0.023 (3)0.005 (4)
C10.058 (5)0.019 (4)0.049 (5)0.0000.010 (5)0.000
C20.051 (3)0.013 (3)0.053 (4)−0.004 (3)−0.011 (3)−0.016 (3)
C30.058 (4)0.022 (3)0.045 (4)−0.005 (3)−0.008 (3)−0.010 (3)
C40.051 (5)0.021 (4)0.040 (5)0.0000.005 (4)0.000
C50.0410.0410.0410.0000.0000.000
C60.058 (5)0.052 (5)0.046 (5)−0.010 (4)0.010 (4)−0.018 (4)
C70.067 (5)0.095 (8)0.090 (7)0.020 (6)0.000 (5)−0.012 (6)
C80.037 (3)0.059 (5)0.094 (6)0.009 (4)−0.011 (4)−0.055 (6)
C90.077 (5)0.018 (3)0.084 (5)−0.005 (4)0.004 (5)−0.001 (5)

Geometric parameters (Å, °)

Br—C21.866 (6)C3—C51.476 (9)
O1—C51.353 (7)C4—C3i1.372 (8)
O1—C61.366 (8)C4—H4A0.9300
O2—C61.213 (9)C5—H5A0.9800
O3—C81.349 (9)C6—C71.445 (10)
O3—C51.461 (9)C7—H7A0.9600
O4—C81.177 (8)C7—H7B0.9600
C1—C21.371 (7)C7—H7C0.9600
C1—C2i1.371 (7)C8—C91.552 (8)
C1—H1A0.9300C9—H9A0.9600
C2—C31.450 (8)C9—H9B0.9600
C3—C41.372 (8)C9—H9C0.9600
C5—O1—C6121.4 (6)C3—C5—H5A109.6
C8—O3—C5118.0 (5)O2—C6—O1120.5 (7)
C2—C1—C2i121.6 (8)O2—C6—C7125.0 (7)
C2—C1—H1A119.2O1—C6—C7114.1 (6)
C2i—C1—H1A119.2C6—C7—H7A109.5
C1—C2—C3119.6 (6)C6—C7—H7B109.5
C1—C2—Br119.4 (4)H7A—C7—H7B109.5
C3—C2—Br121.0 (5)C6—C7—H7C109.5
C4—C3—C2117.9 (6)H7A—C7—H7C109.5
C4—C3—C5124.6 (6)H7B—C7—H7C109.5
C2—C3—C5117.5 (6)O4—C8—O3124.6 (7)
C3i—C4—C3123.3 (8)O4—C8—C9126.0 (8)
C3i—C4—H4A118.4O3—C8—C9109.3 (6)
C3—C4—H4A118.4C8—C9—H9A109.5
O1—C5—O3105.5 (5)C8—C9—H9B109.5
O1—C5—C3110.4 (5)H9A—C9—H9B109.5
O3—C5—C3112.0 (5)C8—C9—H9C109.5
O1—C5—H5A109.6H9A—C9—H9C109.5
O3—C5—H5A109.6H9B—C9—H9C109.5
C2i—C1—C2—C32.3 (4)C8—O3—C5—O1147.6 (5)
C2i—C1—C2—Br−177.1 (5)C8—O3—C5—C3−92.3 (7)
C1—C2—C3—C4−4.6 (9)C4—C3—C5—O1109.4 (6)
Br—C2—C3—C4174.8 (3)C2—C3—C5—O1−68.3 (8)
C1—C2—C3—C5173.3 (5)C4—C3—C5—O3−7.8 (8)
Br—C2—C3—C5−7.3 (9)C2—C3—C5—O3174.5 (6)
C2—C3—C4—C3i2.2 (4)C5—O1—C6—O27.5 (12)
C5—C3—C4—C3i−175.5 (7)C5—O1—C6—C7−166.4 (6)
C6—O1—C5—O3−96.1 (7)C5—O3—C8—O47.9 (10)
C6—O1—C5—C3142.8 (6)C5—O3—C8—C9−174.6 (6)

Symmetry codes: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C4—H4A···O30.932.462.815 (7)103
C5—H5A···O20.982.342.693 (9)100
C7—H7C···O2ii0.962.373.318 (11)170

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH2578).

References

  • Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
  • Bruker (2000). SHELXTL Bruker AXS Inc., Madison, Wisconsin, USA.
  • Enraf–Nonius (1985). CAD-4 Software Version 5.0. Enraf–Nonius, Delft, The Netherlands.
  • Harms, K. & Wocadlo, S. (1995). XCAD4 University of Marburg, Germany.
  • Mitchell, R. H., Iyer, V. S., Khalifa, N., Mahadevan, R., Venugopalan, S., Weerawarna, S. A. & Zhou, P. Z. (1995). J. Am. Chem. Soc.117, 1514–1532.
  • North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.
  • Sheldrick, G. M. (1997). SHELXS97 and SHELXL97 University of Göttingen, Germany.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography