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Acta Crystallographica Section E: Structure Reports Online logoLink to Acta Crystallographica Section E: Structure Reports Online
. 2007 Dec 18;64(Pt 1):o280. doi: 10.1107/S1600536807065415

2-Bromo-5-iodo-1,3-dimethyl­benzene

Rui Liu a, Wen-Yuan Wu a, Yu-Hao Li a, Shui-Ping Deng a, Hong-Jun Zhu a,*
PMCID: PMC2915333  PMID: 21200846

Abstract

In the mol­ecule of the title compound, C8H6BrI, the H atoms of methyl groups are disordered; site-occupation factors were fixed at 0.50. The non-H atoms all lie on a crystallographic mirror plane. Weak intra­molecular C—H⋯Br hydrogen bonds result in the formation of two non-planar five-membered rings.

Related literature

For bond-length data, see: Allen et al. (1987).graphic file with name e-64-0o280-scheme1.jpg

Experimental

Crystal data

  • C8H8BrI

  • M r = 310.94

  • Orthorhombic, Inline graphic

  • a = 16.686 (3) Å

  • b = 7.0640 (14) Å

  • c = 8.2130 (16) Å

  • V = 968.1 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 7.37 mm−1

  • T = 294 (2) K

  • 0.40 × 0.20 × 0.10 mm

Data collection

  • Enraf–Nonius CAD-4 diffractometer

  • Absorption correction: ψ scan (North et al., 1968) T min = 0.157, T max = 0.479

  • 1030 measured reflections

  • 1030 independent reflections

  • 659 reflections with I > 2σ(I)

  • 3 standard reflections frequency: 120 min intensity decay: none

Refinement

  • R[F 2 > 2σ(F 2)] = 0.056

  • wR(F 2) = 0.137

  • S = 1.10

  • 1030 reflections

  • 63 parameters

  • H-atom parameters constrained

  • Δρmax = 0.62 e Å−3

  • Δρmin = −0.85 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807065415/hk2261sup1.cif

e-64-0o280-sup1.cif (13.9KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807065415/hk2261Isup2.hkl

e-64-0o280-Isup2.hkl (51.1KB, hkl)

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A D—H H⋯A DA D—H⋯A
C7—H7C⋯Br2 0.96 2.74 3.156 (6) 107
C8—H8C⋯Br2 0.96 2.77 3.115 (5) 102

Acknowledgments

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

supplementary crystallographic information

Comment

The title compound, (I), is a fine organic intermediate, which can be utilized to construct practical functional molecules. We herein report its crystal structure.

In the molecule of (I), (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987). When the crystal structure was solved, H atoms of methyl groups were found to be disordered.

The atoms Br2, I1, C7 and C8 lie in the benzene ring plane. The weak intra- molecular C—H···Br hydrogen bonds (Table 1) result in the formations of two non-planar five-membered rings; B (Br2/C1/C6/C7/H7C) and C (Br2/C1/C2/C8/H8C). Ring A (C1—C6) is, of course, planar.

As can be seen from the packing diagram, (Fig. 2), the molecules are stacked along the b axis.

Experimental

For the preparation of the title compound, 4-iodo-2,6-dimethylaniline (5.0 g, 20 mmol), concentrated sulfuric acid (40 mmol, 2.23 ml) and water (100 ml) were stirred in an ice bath. When the temperature was below 278 K, the solution of sodium nitrite (1.44 g, 21 mmol) in water (100 ml) was added dropwise. Then, the mixture was added to a solution of CuBr (2.86 g, 20 mmol) and hydrobromic acid (20 mmol, 2.71 ml) with stirring. The solid residue was extracted with boiling hexane (40 ml) and hexane was distilled off. Crystals suitable for X-ray analysis were obtained by slow evaporation of ethanol at room temperature for about 20 d.

Refinement

When the crystal structure was solved, the H atoms of methyl groups were found to be disordered over two mirror image sites of the symmetry plane passing through the benzene ring. The occupancies of disordered H atoms were kept fixed as 0.50. H atoms were positioned geometrically, with C—H = 0.93 and 0.96 Å for aromatic and methyl H, respectively, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.2 for aromatic H, and x = 1.5 for methyl H atoms.

Figures

Fig. 1.

Fig. 1.

The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines.

Fig. 2.

Fig. 2.

A packing diagram of (I). Hydrogen bonds are shown as dashed lines.

Crystal data

C8H8BrI Dx = 2.133 Mg m3
Mr = 310.94 Melting point: 307 K
Orthorhombic, Pnma Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ac 2n Cell parameters from 25 reflections
a = 16.686 (3) Å θ = 10–13º
b = 7.0640 (14) Å µ = 7.37 mm1
c = 8.2130 (16) Å T = 294 (2) K
V = 968.1 (3) Å3 Needle, colorless
Z = 4 0.40 × 0.20 × 0.10 mm
F000 = 576.0

Data collection

Enraf–Nonius CAD-4 diffractometer Rint = 0.0000
Radiation source: fine-focus sealed tube θmax = 26.0º
Monochromator: graphite θmin = 2.4º
T = 294(2) K h = 0→20
ω/2θ scans k = 0→8
Absorption correction: ψ scan(North et al., 1968) l = 0→10
Tmin = 0.157, Tmax = 0.479 3 standard reflections
1030 measured reflections every 120 min
1030 independent reflections intensity decay: none
659 reflections with I > 2σ(I)

Refinement

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)] = 0.056 H-atom parameters constrained
wR(F2) = 0.137   w = 1/[σ2(Fo2) + (0.0602P)2 + 1.4567P] where P = (Fo2 + 2Fc2)/3
S = 1.10 (Δ/σ)max < 0.001
1030 reflections Δρmax = 0.62 e Å3
63 parameters Δρmin = −0.85 e Å3
Primary atom site location: structure-invariant direct methods Extinction correction: none

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)

x y z Uiso*/Ueq Occ. (<1)
I1 0.25441 (7) 0.2500 1.15579 (9) 0.0902 (5)
Br2 −0.08058 (5) 0.2500 0.69651 (7) 0.0800 (5)
C1 0.0160 (4) 0.2500 0.8282 (5) 0.055 (3)
C2 0.0066 (4) 0.2500 0.9955 (6) 0.051 (3)
C3 0.0768 (4) 0.2500 1.0850 (6) 0.054 (3)
H3 0.0740 0.2500 1.1981 0.065*
C4 0.1500 (5) 0.2500 1.0117 (6) 0.057 (3)
C5 0.1580 (5) 0.2500 0.8449 (5) 0.055 (3)
H5 0.2085 0.2500 0.7972 0.066*
C6 0.0897 (4) 0.2500 0.7489 (5) 0.050 (3)
C7 0.0984 (4) 0.2500 0.5721 (4) 0.093 (5)
H7A 0.0947 0.1226 0.5322 0.139* 0.50
H7B 0.1496 0.3022 0.5434 0.139* 0.50
H7C 0.0567 0.3252 0.5244 0.139* 0.50
C8 −0.0730 (4) 0.2500 1.0755 (6) 0.077 (4)
H8A −0.0672 0.2878 1.1871 0.116* 0.50
H8B −0.0955 0.1251 1.0709 0.116* 0.50
H8C −0.1078 0.3371 1.0203 0.116* 0.50

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23
I1 0.0675 (6) 0.1300 (10) 0.0731 (6) 0.000 −0.0170 (5) 0.000
Br2 0.0850 (9) 0.0714 (8) 0.0837 (9) 0.000 −0.0394 (8) 0.000
C1 0.065 (7) 0.038 (6) 0.063 (8) 0.000 −0.022 (6) 0.000
C6 0.074 (7) 0.049 (5) 0.047 (6) 0.000 0.006 (5) 0.000
C4 0.068 (7) 0.057 (7) 0.046 (7) 0.000 0.002 (6) 0.000
C3 0.079 (8) 0.053 (6) 0.031 (5) 0.000 0.012 (6) 0.000
C2 0.054 (5) 0.046 (6) 0.052 (7) 0.000 0.010 (5) 0.000
C5 0.060 (6) 0.059 (7) 0.045 (6) 0.000 0.017 (5) 0.000
C7 0.108 (13) 0.098 (10) 0.083 (6) 0.000 0.012 (7) 0.000
C8 0.071 (8) 0.079 (8) 0.082 (9) 0.000 0.003 (7) 0.000

Geometric parameters (Å, °)

I1—C4 2.105 (7) C3—H3 0.9300
Br2—C1 1.941 (6) C2—C8 1.481 (6)
C1—C2 1.383 (6) C5—H5 0.9300
C1—C6 1.392 (6) C7—H7A 0.9600
C6—C5 1.385 (6) C7—H7B 0.9600
C6—C7 1.460 (5) C7—H7C 0.9600
C4—C3 1.362 (6) C8—H8A 0.9600
C4—C5 1.377 (6) C8—H8B 0.9600
C3—C2 1.384 (6) C8—H8C 0.9600
C2—C1—C6 124.4 (5) C4—C5—C6 119.2 (5)
C2—C1—Br2 117.4 (5) C4—C5—H5 120.4
C6—C1—Br2 118.2 (3) C6—C5—H5 120.4
C5—C6—C1 117.4 (4) C6—C7—H7A 109.5
C5—C6—C7 118.9 (5) C6—C7—H7B 109.5
C1—C6—C7 123.6 (5) H7A—C7—H7B 109.5
C3—C4—C5 121.7 (4) C6—C7—H7C 109.5
C3—C4—I1 119.6 (4) H7A—C7—H7C 109.5
C5—C4—I1 118.7 (4) H7B—C7—H7C 109.5
C4—C3—C2 121.6 (5) C2—C8—H8A 109.5
C4—C3—H3 119.2 C2—C8—H8B 109.5
C2—C3—H3 119.2 H8A—C8—H8B 109.5
C1—C2—C3 115.6 (5) C2—C8—H8C 109.5
C1—C2—C8 122.8 (6) H8A—C8—H8C 109.5
C3—C2—C8 121.5 (5) H8B—C8—H8C 109.5
C2—C1—C6—C5 0.000 (3) C6—C1—C2—C8 180.000 (3)
Br2—C1—C6—C5 180.000 (2) Br2—C1—C2—C8 0.000 (3)
C2—C1—C6—C7 180.000 (2) C4—C3—C2—C1 0.000 (3)
Br2—C1—C6—C7 0.000 (2) C4—C3—C2—C8 180.000 (3)
C5—C4—C3—C2 0.000 (3) C3—C4—C5—C6 0.000 (3)
I1—C4—C3—C2 180.000 (3) I1—C4—C5—C6 180.000 (2)
C6—C1—C2—C3 0.000 (3) C1—C6—C5—C4 0.000 (3)
Br2—C1—C2—C3 180.000 (2) C7—C6—C5—C4 180.000 (2)

Hydrogen-bond geometry (Å, °)

D—H···A D—H H···A D···A D—H···A
C7—H7C···Br2 0.96 2.74 3.156 (6) 107
C8—H8C···Br2 0.96 2.77 3.115 (5) 102

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HK2261).

References

  1. 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.
  2. Bruker (2000). SHELXTL Bruker AXS Inc., Madison, Wisconsin, USA.
  3. Enraf–Nonius (1985). CAD-4 Software Version 5.0. Enraf–Nonius, Delft, The Netherlands.
  4. Harms, K. & Wocadlo, S. (1995). XCAD4 University of Marburg, Germany.
  5. North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.
  6. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97 University of Göttingen, Germany.
  7. Spek, A. L. (2003). J. Appl. Cryst.36, 7–13.

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807065415/hk2261sup1.cif

e-64-0o280-sup1.cif (13.9KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807065415/hk2261Isup2.hkl

e-64-0o280-Isup2.hkl (51.1KB, hkl)

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


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