organic compounds
2-Bromo-5-iodo-1,3-dimethylbenzene
aDepartment of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China
*Correspondence e-mail: zhuhj@njut.edu.cn
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.
Experimental
Crystal data
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Refinement
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Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell 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).
Supporting information
https://doi.org/10.1107/S1600536807065415/hk2261sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807065415/hk2261Isup2.hkl
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.
When the
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.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
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.
For bond-length data, see: Allen et al. (1987).
Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell
CAD-4 Software (Enraf–Nonius, 1985); 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).C8H8BrI | Dx = 2.133 Mg m−3 |
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 = 10–13° |
b = 7.0640 (14) Å | µ = 7.37 mm−1 |
c = 8.2130 (16) Å | T = 294 K |
V = 968.1 (3) Å3 | Needle, colorless |
Z = 4 | 0.40 × 0.20 × 0.10 mm |
F(000) = 576.0 |
Enraf–Nonius CAD-4 diffractometer | 659 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 26.0°, θmin = 2.4° |
ω/2θ scans | h = 0→20 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→8 |
Tmin = 0.157, Tmax = 0.479 | l = 0→10 |
1030 measured reflections | 3 standard reflections every 120 min |
1030 independent reflections | intensity decay: none |
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)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0602P)2 + 1.4567P] where P = (Fo2 + 2Fc2)/3 |
1030 reflections | (Δ/σ)max < 0.001 |
63 parameters | Δρmax = 0.62 e Å−3 |
0 restraints | Δρmin = −0.85 e Å−3 |
C8H8BrI | V = 968.1 (3) Å3 |
Mr = 310.94 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 16.686 (3) Å | µ = 7.37 mm−1 |
b = 7.0640 (14) Å | T = 294 K |
c = 8.2130 (16) Å | 0.40 × 0.20 × 0.10 mm |
Enraf–Nonius CAD-4 diffractometer | 659 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.000 |
Tmin = 0.157, Tmax = 0.479 | 3 standard reflections every 120 min |
1030 measured reflections | intensity decay: none |
1030 independent reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.10 | Δρmax = 0.62 e Å−3 |
1030 reflections | Δρmin = −0.85 e Å−3 |
63 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 | 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 |
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 |
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) |
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 |
Experimental details
Crystal data | |
Chemical formula | C8H8BrI |
Mr | 310.94 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 294 |
a, b, c (Å) | 16.686 (3), 7.0640 (14), 8.2130 (16) |
V (Å3) | 968.1 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 7.37 |
Crystal size (mm) | 0.40 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.157, 0.479 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1030, 1030, 659 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.616 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.137, 1.10 |
No. of reflections | 1030 |
No. of parameters | 63 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.62, −0.85 |
Computer programs: CAD-4 Software (Enraf–Nonius, 1985), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXTL (Bruker, 2000).
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7C···Br2 | 0.96 | 2.740 | 3.156 (6) | 107.00 |
C8—H8C···Br2 | 0.96 | 2.770 | 3.115 (5) | 102.00 |
Acknowledgements
The authors thank the Center of Testing and Analysis, Nanjing University, for support.
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. CSD CrossRef Web of Science Google Scholar
Bruker (2000). SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Enraf–Nonius (1985). CAD-4 Software. Version 5.0. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
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.