Bis(2,4 di­bromo­phenyl) ether

organic papers

o1424

Structure Reports Online

ISSN 1600-5368

Bis(2,4-dibromophenyl) ether

Lars Eriksson,a_{* Johan Eriksson}b and Jiwei Huc

a_{Division of Structural Chemistry, Arrhenius}

Laboratory, Stockholm University, S-106 91 Stockholm, Sweden,b_{Department of} Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, andc_{Department of Applied} Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study T= 293 K

Mean(C±C) = 0.005 AÊ Rfactor = 0.029 wRfactor = 0.050

Data-to-parameter ratio = 17.4

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved

Packing effects are shown to be of minor importance in determining the molecular conformation of the title compound, C12H6Br4O, by comparison with a conformational

map calculated with semi-empirical (AM1) calculations.

Comment

The title compound, (I) (Fig. 1), crystallizes with two mol-ecules in the asymmetric unit, a situation not occurring in the other brominated diphenyl ethers with known crystal struc-tures. All four benzene rings are planar to within 0.01 (1) AÊ. No anomalous bond distances or angles are found (Table 1). The two rings of molecule 1, C1±C6 and C7±C12, are inclined at 67.5 (1) _{to each other, and the two rings of molecule 2,}

C13±C18 and C19±C24, are inclined at 62.0 (1)_{to each other.}

The orientational relation between the two unique mol-ecules, shown in Fig. 2, was computed using the program

ROTERA (Norrestam, 2004; Diamond, 1988). The average

deviation between the atoms in the two molecules, one of them rotated to a perfect overlap with the central O and neighbouring C atoms, is 0.22 AÊ. The similarity between the two molecules can also be deduced from the similar torsion angles involving the ether O atom in the two molecules (Table 1). The observed torsion angles de®ning the relative

Received 28 June 2004 Accepted 16 July 2004 Online 31 July 2004

Figure 1

orientation of the aromatic rings can be reproduced by semi-empirical calculations using the AM1 Hamiltonian with

MOPAC-6 (Stewart, 1990), to an average discrepancy

between observed and calculated torsion angles of 10_.

Several broad shallow minima can be detected in the complete torsion map, shown in Fig. 3, computed withMOPAC-6 with 10 _{spacing for the two torsion angles de®ning the}

confor-mation over the ether O atom. Thus, one may draw the conclusion that packing effects are of minor importance in determining the conformations of the molecules comprising (I).

The two shortest intermolecular Br Br contacts are Br2 Br4i _{[3.808 (1) AÊ; symmetry code: (i) 1ÿx, 1ÿy,}

1ÿz] and Br2 Br7i _{[3.779 (1) AÊ]. These intermolecular}

Br Br distances cannot be regarded as short in a comparison with similar intermolecular Br Br contacts for Br-substi-tuted aromatic substances found in a search of the Cambridge Structural Database (CSD, Version 5.25 of November 2003; Allen, 2002; Orpen, 2002; Allen & Motherwell, 2002; Taylor, 2002). The intermolecular Br Br contacts in (I) shorter than 4.15 AÊ are mediating contacts between different molecules in the a direction. The cut-off distance of 4.15 AÊ should be considered long for Br Br interactions when compared with other Br Br contacts found in the CSD. Most of the inter-molecular Br Br Br angles for the above-mentioned contacts shorter than 4.15 AÊ are close to 90_{, and none is less}

than 55_.

Experimental

The synthesis of the title compound has been descibed earlier by Hu (1999). Crystals of (I) were obtained from a solution in ethanol.

Crystal data

C12H6Br4O Mr= 485.81 Monoclinic,P21=c a= 8.5568 (14) AÊ

b= 13.822 (2) AÊ

c= 23.295 (4) AÊ

= 90.842 (19)

V= 2754.9 (8) AÊ3 Z= 8

Dx= 2.343 Mg mÿ3 MoKradiation Cell parameters from 962

re¯ections

= 3.3±52.0

= 11.67 mmÿ1 T= 293 (2) K Prism, colourless 0.260.100.08 mm

Data collection

Stoe IPDS area-detector diffractometer

'scans

Absorption correction: numerical (X-RED; Stoe, 1997)

Tmin= 0.047,Tmax= 0.356

15 424 measured re¯ections

5341 independent re¯ections 3087 re¯ections withI> 2(I)

Rint= 0.095

max= 26.0 h=ÿ10!10

k=ÿ16!16

l=ÿ28!28

Re®nement

Re®nement onF2 R[F2_{> 2(F}2_{)] = 0.029} wR(F2_{) = 0.050} S= 0.86 5341 re¯ections 307 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.0151)2] whereP= (Fo2+ 2Fc2)/3 (/)max= 0.001

max= 0.39 e AÊÿ3

min=ÿ0.31 e AÊÿ3

Table 1

Selected geometric parameters (AÊ,_).

Br1ÐC2 1.885 (3)

Br2ÐC4 1.898 (3)

Br3ÐC8 1.893 (4)

Br4ÐC10 1.891 (3)

Br5ÐC14 1.885 (3)

Br6ÐC16 1.895 (3)

Br7ÐC20 1.896 (3)

Br8ÐC22 1.909 (3)

C1ÐO1ÐC7 118.6 (3)

C2ÐC1ÐO1 115.1 (3)

O1ÐC1ÐC6 124.4 (3)

C12ÐC7ÐO1 122.6 (3)

C8ÐC7ÐO1 117.2 (3)

C13ÐO2ÐC19 120.1 (3)

C18ÐC13ÐO2 123.6 (3)

O2ÐC13ÐC14 116.3 (3)

C20ÐC19ÐO2 115.3 (3)

C24ÐC19ÐO2 124.4 (3)

C7ÐO1ÐC1ÐC2 ÿ155.4 (3)

C7ÐO1ÐC1ÐC6 27.7 (5)

C1ÐO1ÐC7ÐC12 50.0 (5)

C1ÐO1ÐC7ÐC8 ÿ135.7 (3)

C19ÐO2ÐC13ÐC18 47.2 (5)

C19ÐO2ÐC13ÐC14 ÿ139.8 (3)

C13ÐO2ÐC19ÐC20 ÿ159.5 (3)

C13ÐO2ÐC19ÐC24 25.2 (5)

organic papers

Acta Cryst.(2004). E60, o1424±o1426 Lars Erikssonet al. C₁₂H₆Br₄O

o1425

Figure 2

A stereoview of an overlay of the two unique molecules of (I), one of them rotated to a perfect overlap at the O and its two neighbouring C atoms.

Figure 3

A conformational map of (I) with heat of formation as a function of the two torsion angles C2ÐC1ÐO1ÐC7 and C1ÐO1ÐC7ÐC8, or similar torsion angles in the second molecule. The contour levels are marked at 1 kcal molÿ1 _{spacing from 51 to 64 kcal mol}ÿ1 _{(1 kcal mol}ÿ1 ₌

4.184 kJ molÿ1_{). The conformations of the two molecules are indicated}

TheRintvalue is rather high, due in large part to unobserved and/

or weak re¯ections. Neglecting all re¯ections with negative observed intensity (none more signi®cant than 3.5) decreasesRintto 0.073.

Furthermore, if all re¯ections less signi®cant than 3are omitted,Rint

drops to 0.051. This shows clearly that a large number of weak re¯ections make large contributions toRint. H atoms were placed in

geometrical positions and re®ned as riding, with CÐH distances of 0.93 AÊ andUiso(H) = 1.2Ueq(C).

Data collection:EXPOSEinIPDS(Stoe, 1997); cell re®nement:

CELLinIPDS; data reduction:INTEGRATEinIPDS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:DIAMOND(Bergerhoff, 1996); software used to prepare material for publication:EASYPLOT(Karon, 1999)

This work was supported by the Swedish Natural Science Research Council.

References

Allen, F. H. (2002).Acta Cryst.B58, 380±388.

Allen, F. H. & Motherwell, W. D. S. (2002).Acta Cryst.B58, 407±422. Bergerhoff, G. (1996). DIAMOND. Gerhard-Domagk-str. 1, 53121 Bonn,

Germany.

Diamond, R. (1988).Acta Cryst.A44, 211±216.

Hu, J. (1999). PhD thesis, University of JyvaÈskylaÈ, Finland. ISBN 951±39± 0524±1.

Karon, S. (1999).EASYPLOT. Spiral Software, 57 Baker Hill Road, Lyme, NH 03768, http://www.spiralsoftware.com/ep/eplot.html

Norrestam, R. (2004).ROTERA. Division of Structural Chemistry, Stockholm University, Sweden.

Orpen, A. G. (2002).Acta Cryst.B58, 398±406. Sheldrick, G. M. (1990).Acta Cryst.A46, 467±473.

Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany. Stewart, J. J. P. (1990). MOPAC-6 Manual. Quantum Chemistry Program

Exchange (QCPE-455), Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA. http://qcpe.chem.indiana.edu/ Stoe (1997).IPDS(Version 2.87) andX-RED(Version 1.09). Stoe & Cie,

Darmstadt, Germany.

Taylor, R. (2002).Acta Cryst.B58, 879±888.

organic papers

supporting information

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Acta Cryst. (2004). E60, o1424–o1426

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Acta Cryst. (2004). E60, o1424–o1426 [https://doi.org/10.1107/S1600536804017520]

Bis(2,4-dibromophenyl) ether

Lars Eriksson, Johan Eriksson and Jiwei Hu

bis(2,4-dibromophenyl) ether

Crystal data C12H6Br4O Mr = 485.81

Monoclinic, P21/c Hall symbol: -P 2ybc a = 8.5568 (14) Å b = 13.822 (2) Å c = 23.295 (4) Å β = 90.842 (19)° V = 2754.9 (8) Å3 Z = 8

F(000) = 1808 Dx = 2.343 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 962 reflections θ = 3.3–52.0°

µ = 11.67 mm−1 T = 293 K Prism, colourless 0.26 × 0.10 × 0.08 mm

Data collection

Stoe IPDS area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Detector resolution: 6.0 pixels mm-1 φ scans

Absorption correction: numerical (X-RED; Stoe, 1997)

Tmin = 0.047, Tmax = 0.356

15424 measured reflections 5341 independent reflections 3087 reflections with I > 2σ(I) Rint = 0.095

θmax = 26.0°, θmin = 2.3° h = −10→10

k = 0→16 l = 0→28

Refinement Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.029} wR(F2_{) = 0.050} S = 0.86 5341 reflections 307 parameters 86 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H-atom parameters constrained w = 1/[σ2_(F

o2) + (0.0151)2] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max = 0.001

Δρmax = 0.39 e Å−3 Δρmin = −0.31 e Å−3

Special details

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Acta Cryst. (2004). E60, o1424–o1426

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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 Br1 0.22693 (5) 0.10196 (3) 0.444519 (16) 0.07367 (12) Br2 0.52395 (5) 0.39502 (3) 0.317476 (15) 0.07724 (13) Br3 0.52253 (5) 0.12181 (3) 0.640669 (17) 0.07372 (12) Br4 0.24658 (5) 0.42158 (3) 0.769469 (15) 0.08220 (14) O1 0.3457 (3) 0.21903 (19) 0.54409 (10) 0.0805 (8) C1 0.3833 (4) 0.2666 (3) 0.49348 (13) 0.0564 (9) C2 0.3363 (4) 0.2204 (2) 0.44378 (13) 0.0531 (8) C3 0.3774 (4) 0.2603 (3) 0.39112 (13) 0.0555 (9)

H3 0.3473 0.2300 0.3571 0.067*

C4 0.4634 (4) 0.3451 (3) 0.38973 (14) 0.0575 (9) C5 0.5106 (4) 0.3904 (3) 0.43928 (14) 0.0624 (9)

H5 0.5705 0.4465 0.4377 0.075*

C6 0.4694 (4) 0.3527 (3) 0.49095 (15) 0.0666 (10)

H6 0.4985 0.3843 0.5247 0.080*

C7 0.3318 (4) 0.2734 (3) 0.59426 (14) 0.0606 (9) C8 0.4015 (4) 0.2362 (2) 0.64405 (13) 0.0523 (8) C9 0.3764 (4) 0.2815 (3) 0.69600 (12) 0.0509 (8)

H9 0.4215 0.2569 0.7295 0.061*

C10 0.2849 (4) 0.3624 (3) 0.69784 (13) 0.0593 (9) C11 0.2181 (4) 0.4006 (3) 0.64834 (14) 0.0599 (9)

H11 0.1571 0.4562 0.6500 0.072*

C12 0.2426 (4) 0.3558 (3) 0.59699 (14) 0.0651 (10)

H12 0.1984 0.3813 0.5636 0.078*

Br5 0.99674 (5) 0.39707 (3) 0.442417 (16) 0.07397 (12) Br6 0.71024 (5) 0.10467 (3) 0.309574 (15) 0.07971 (13) Br7 0.75034 (5) 0.40544 (3) 0.637591 (16) 0.07185 (12) Br8 1.07147 (5) 0.11760 (4) 0.763727 (15) 0.08180 (14) O2 0.8506 (3) 0.28639 (19) 0.53846 (9) 0.0864 (8) C13 0.8307 (4) 0.2353 (3) 0.48784 (13) 0.0587 (9) C14 0.8853 (4) 0.2795 (2) 0.43851 (13) 0.0499 (8) C15 0.8502 (4) 0.2398 (3) 0.38567 (12) 0.0531 (9)

H15 0.8830 0.2698 0.3522 0.064*

C16 0.7648 (4) 0.1539 (3) 0.38309 (13) 0.0524 (8) C17 0.7147 (4) 0.1085 (3) 0.43131 (13) 0.0604 (9)

H17 0.6600 0.0504 0.4289 0.073*

C18 0.7469 (4) 0.1503 (3) 0.48358 (14) 0.0665 (10)

H18 0.7116 0.1208 0.5168 0.080*

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H21 0.8935 0.2819 0.7259 0.067*

C22 0.9943 (4) 0.1631 (3) 0.69128 (14) 0.0585 (9) C23 1.0241 (4) 0.1120 (3) 0.64270 (14) 0.0655 (10)

H23 1.0747 0.0525 0.6445 0.079*

C24 0.9768 (4) 0.1511 (3) 0.59041 (15) 0.0692 (10)

H24 0.9997 0.1191 0.5564 0.083*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

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Acta Cryst. (2004). E60, o1424–o1426 Geometric parameters (Å, º)

Br1—C2 1.885 (3) Br5—C14 1.885 (3)

Br2—C4 1.898 (3) Br6—C16 1.895 (3)

Br3—C8 1.893 (4) Br7—C20 1.896 (3)

Br4—C10 1.891 (3) Br8—C22 1.909 (3)

O1—C1 1.392 (4) O2—C13 1.383 (4)

O1—C7 1.396 (4) O2—C19 1.395 (4)

C1—C2 1.377 (4) C13—C18 1.379 (5)

C1—C6 1.401 (5) C13—C14 1.389 (4)

C2—C3 1.395 (4) C14—C15 1.377 (4)

C3—C4 1.385 (5) C15—C16 1.395 (4)

C3—H3 0.9300 C15—H15 0.9300

C4—C5 1.369 (4) C16—C17 1.361 (4)

C5—C6 1.363 (4) C17—C18 1.372 (4)

C5—H5 0.9300 C17—H17 0.9300

C6—H6 0.9300 C18—H18 0.9300

C7—C12 1.373 (5) C19—C20 1.393 (4)

C7—C8 1.394 (4) C19—C24 1.394 (5)

C8—C9 1.382 (4) C20—C21 1.383 (4)

C9—C10 1.367 (5) C21—C22 1.385 (5)

C9—H9 0.9300 C21—H21 0.9300

C10—C11 1.384 (4) C22—C23 1.361 (5)

C11—C12 1.366 (4) C23—C24 1.388 (5)

C11—H11 0.9300 C23—H23 0.9300

C12—H12 0.9300 C24—H24 0.9300

C1—O1—C7 118.6 (3) C13—O2—C19 120.1 (3)

C2—C1—O1 115.1 (3) C18—C13—O2 123.6 (3)

C2—C1—C6 120.4 (3) C18—C13—C14 119.8 (3)

O1—C1—C6 124.4 (3) O2—C13—C14 116.3 (3)

C1—C2—C3 118.8 (3) C15—C14—C13 119.5 (3)

C1—C2—Br1 122.3 (3) C15—C14—Br5 119.4 (2)

C3—C2—Br1 118.9 (3) C13—C14—Br5 121.0 (3)

C4—C3—C2 119.8 (3) C14—C15—C16 119.0 (3)

C4—C3—H3 120.1 C14—C15—H15 120.5

C2—C3—H3 120.1 C16—C15—H15 120.5

C5—C4—C3 121.2 (3) C17—C16—C15 121.9 (3)

C5—C4—Br2 120.0 (3) C17—C16—Br6 120.3 (3)

C3—C4—Br2 118.7 (3) C15—C16—Br6 117.8 (2)

C6—C5—C4 119.5 (4) C16—C17—C18 118.4 (3)

C6—C5—H5 120.2 C16—C17—H17 120.8

C4—C5—H5 120.2 C18—C17—H17 120.8

C5—C6—C1 120.3 (3) C17—C18—C13 121.4 (3)

C5—C6—H6 119.8 C17—C18—H18 119.3

C1—C6—H6 119.8 C13—C18—H18 119.3

C12—C7—C8 119.9 (3) C20—C19—C24 120.1 (3)

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Acta Cryst. (2004). E60, o1424–o1426

C8—C7—O1 117.2 (3) C24—C19—O2 124.4 (3)

C9—C8—C7 119.4 (3) C21—C20—C19 120.0 (3)

C9—C8—Br3 120.4 (3) C21—C20—Br7 119.7 (2)

C7—C8—Br3 120.1 (3) C19—C20—Br7 120.3 (3)

C10—C9—C8 119.6 (3) C20—C21—C22 118.0 (3)

C10—C9—H9 120.2 C20—C21—H21 121.0

C8—C9—H9 120.2 C22—C21—H21 121.0

C9—C10—C11 121.1 (3) C23—C22—C21 123.6 (3) C9—C10—Br4 119.2 (3) C23—C22—Br8 119.9 (3) C11—C10—Br4 119.7 (3) C21—C22—Br8 116.5 (3) C12—C11—C10 119.3 (4) C22—C23—C24 118.2 (4)

C12—C11—H11 120.3 C22—C23—H23 120.9

C10—C11—H11 120.3 C24—C23—H23 120.9

C11—C12—C7 120.6 (3) C23—C24—C19 120.1 (3)

C11—C12—H12 119.7 C23—C24—H24 120.0

C7—C12—H12 119.7 C19—C24—H24 120.0