Acta Cryst. (2008). E64, o1930 [ doi:10.1107/S1600536808028730 ]
In the centrosymmetric title compound, C18H28Br2O2, the alkyl chains adopt a fully extended all-trans conformation and each of them is almost planar. In addition, the alkyl chains are coplanar with the benzene ring. Intermolecular Br
Br interactions [3.410 (3) Å] are present, resulting in a one-dimensional supramolecular architecture.
The title compound was prepared as described in literature (Maruyama & Kawanishi 2002) and recrystallized from dichloromethane-ethanol at room temperature to give the desired crystals suitable for single-crystal X-ray diffraction.
H atoms attached to C atoms of the title compound were placed in geometrically idealized positions and treated as riding with C—H distances constrained to 0.93 (aromatic CH), or 0.96 Å (methyl CH3), and 0.97 Å (methylene CH2) and constrained to ride on their parent atoms, with Uĩso~(H) = 1.2Ueq(C)(1.5Ueq for methyl H).
Data collection: SMART (Bruker, 2004); cell refinement: SMART (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); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./si2104fig1thm.gif)
| Fig. 1. The molecular structure of the title compound with displacement ellipsoids at the 50% probability level. Inversion related atoms are labelled with an A. (Symmetry code: -x, 1 - y, -z). |
![[Figure 2]](./si2104fig2thm.gif)
| Fig. 2. Partial view of the crystal packing showing the formation of the infinite chains of molecules formed by the intermolecular Br···Br interactions. Intercalated neighboring chains complete the sheets in the structure running parallel to (100). H atoms have been omitted for clarity. |
| C18H28Br2O2 | Z = 1 |
| Mr = 436.22 | F(000) = 222 |
| Triclinic, P1 | Dx = 1.469 Mg m−3 |
| a = 6.9638 (12) Å | Mo Kα radiation, λ = 0.71073 Å |
| b = 8.2581 (14) Å | Cell parameters from 1772 reflections |
| c = 9.7321 (17) Å | θ = 2.3–26.0° |
| α = 107.012 (2)° | µ = 4.12 mm−1 |
| β = 106.981 (2)° | T = 295 K |
| γ = 99.193 (2)° | Block, colourless |
| V = 493.11 (15) Å3 | 0.28 × 0.27 × 0.07 mm |
| Bruker SMART CCD diffractometer | 1818 independent reflections |
| Radiation source: fine-focus sealed tube | 1567 reflections with I > 2σ(I) |
| graphite | Rint = 0.018 |
| phi and ω scans | θmax = 25.5°, θmin = 2.7° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→8 |
| Tmin = 0.391, Tmax = 0.764 | k = −9→9 |
| 3675 measured reflections | l = −11→11 |
| 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)] = 0.025 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.063 | H-atom parameters constrained |
| S = 1.06 | w = 1/[σ2(Fo2) + (0.0346P)2 + 0.0096P] where P = (Fo2 + 2Fc2)/3 |
| 1818 reflections | (Δ/σ)max = 0.001 |
| 101 parameters | Δρmax = 0.31 e Å−3 |
| 0 restraints | Δρmin = −0.23 e Å−3 |
| C18H28Br2O2 | γ = 99.193 (2)° |
| Mr = 436.22 | V = 493.11 (15) Å3 |
| Triclinic, P1 | Z = 1 |
| a = 6.9638 (12) Å | Mo Kα radiation |
| b = 8.2581 (14) Å | µ = 4.12 mm−1 |
| c = 9.7321 (17) Å | T = 295 K |
| α = 107.012 (2)° | 0.28 × 0.27 × 0.07 mm |
| β = 106.981 (2)° |
| Bruker SMART CCD diffractometer | 1818 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1567 reflections with I > 2σ(I) |
| Tmin = 0.391, Tmax = 0.764 | Rint = 0.018 |
| 3675 measured reflections | θmax = 25.5° |
| R[F2 > 2σ(F2)] = 0.025 | H-atom parameters constrained |
| wR(F2) = 0.063 | Δρmax = 0.31 e Å−3 |
| S = 1.06 | Δρmin = −0.23 e Å−3 |
| 1818 reflections | Absolute structure: ? |
| 101 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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 | ||
| Br1 | 0.07253 (4) | 0.51292 (4) | −0.31314 (3) | 0.05768 (13) | |
| O1 | 0.3731 (2) | 0.6878 (2) | 0.00755 (19) | 0.0577 (5) | |
| C1 | −0.1596 (3) | 0.4127 (3) | −0.1410 (3) | 0.0455 (6) | |
| H1 | −0.2656 | 0.3549 | −0.2366 | 0.055* | |
| C2 | 0.0292 (3) | 0.5069 (3) | −0.1316 (3) | 0.0418 (5) | |
| C3 | 0.1932 (3) | 0.5970 (3) | 0.0107 (3) | 0.0426 (5) | |
| C4 | 0.5450 (3) | 0.7726 (4) | 0.1511 (3) | 0.0513 (6) | |
| H4A | 0.5871 | 0.6864 | 0.1944 | 0.062* | |
| H4B | 0.5056 | 0.8560 | 0.2240 | 0.062* | |
| C5 | 0.7229 (3) | 0.8672 (3) | 0.1183 (3) | 0.0528 (6) | |
| H5A | 0.6775 | 0.9504 | 0.0722 | 0.063* | |
| H5B | 0.7610 | 0.7824 | 0.0455 | 0.063* | |
| C6 | 0.9133 (3) | 0.9647 (3) | 0.2665 (3) | 0.0539 (6) | |
| H6A | 0.8755 | 1.0516 | 0.3377 | 0.065* | |
| H6B | 0.9547 | 0.8817 | 0.3143 | 0.065* | |
| C7 | 1.0979 (3) | 1.0563 (3) | 0.2370 (3) | 0.0518 (6) | |
| H7A | 1.1351 | 0.9693 | 0.1653 | 0.062* | |
| H7B | 1.0564 | 1.1394 | 0.1894 | 0.062* | |
| C8 | 1.2870 (4) | 1.1524 (4) | 0.3828 (3) | 0.0662 (8) | |
| H8A | 1.3355 | 1.0679 | 0.4259 | 0.079* | |
| H8B | 1.2471 | 1.2326 | 0.4576 | 0.079* | |
| C9 | 1.4646 (4) | 1.2556 (5) | 0.3548 (4) | 0.0850 (10) | |
| H9A | 1.5032 | 1.1771 | 0.2795 | 0.127* | |
| H9B | 1.5824 | 1.3105 | 0.4494 | 0.127* | |
| H9C | 1.4200 | 1.3442 | 0.3179 | 0.127* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br1 | 0.05214 (17) | 0.0815 (2) | 0.03895 (16) | 0.00640 (13) | 0.01726 (12) | 0.02627 (13) |
| O1 | 0.0382 (9) | 0.0797 (12) | 0.0427 (9) | −0.0082 (8) | 0.0094 (7) | 0.0224 (9) |
| C1 | 0.0369 (12) | 0.0546 (14) | 0.0350 (12) | 0.0026 (10) | 0.0057 (9) | 0.0142 (11) |
| C2 | 0.0414 (12) | 0.0529 (14) | 0.0330 (11) | 0.0089 (10) | 0.0135 (10) | 0.0199 (10) |
| C3 | 0.0354 (11) | 0.0501 (13) | 0.0392 (12) | 0.0049 (10) | 0.0115 (10) | 0.0168 (11) |
| C4 | 0.0368 (12) | 0.0633 (16) | 0.0417 (13) | −0.0004 (11) | 0.0082 (10) | 0.0151 (12) |
| C5 | 0.0383 (12) | 0.0654 (16) | 0.0481 (14) | 0.0015 (11) | 0.0139 (11) | 0.0193 (12) |
| C6 | 0.0399 (13) | 0.0629 (17) | 0.0504 (14) | 0.0023 (12) | 0.0136 (11) | 0.0172 (13) |
| C7 | 0.0404 (13) | 0.0562 (15) | 0.0535 (15) | 0.0043 (11) | 0.0175 (11) | 0.0160 (12) |
| C8 | 0.0437 (14) | 0.0786 (19) | 0.0592 (17) | −0.0001 (13) | 0.0128 (13) | 0.0150 (15) |
| C9 | 0.0468 (16) | 0.095 (2) | 0.086 (2) | −0.0123 (15) | 0.0179 (16) | 0.0156 (19) |
| Br1—C2 | 1.891 (2) | C5—H5B | 0.9700 |
| O1—C3 | 1.367 (2) | C6—C7 | 1.529 (3) |
| O1—C4 | 1.435 (3) | C6—H6A | 0.9700 |
| C1—C3i | 1.377 (3) | C6—H6B | 0.9700 |
| C1—C2 | 1.379 (3) | C7—C8 | 1.514 (3) |
| C1—H1 | 0.9300 | C7—H7A | 0.9700 |
| C2—C3 | 1.406 (3) | C7—H7B | 0.9700 |
| C3—C1i | 1.377 (3) | C8—C9 | 1.525 (4) |
| C4—C5 | 1.522 (3) | C8—H8A | 0.9700 |
| C4—H4A | 0.9700 | C8—H8B | 0.9700 |
| C4—H4B | 0.9700 | C9—H9A | 0.9600 |
| C5—C6 | 1.533 (3) | C9—H9B | 0.9600 |
| C5—H5A | 0.9700 | C9—H9C | 0.9600 |
| C3—O1—C4 | 117.26 (18) | C7—C6—H6A | 109.1 |
| C3i—C1—C2 | 120.9 (2) | C5—C6—H6A | 109.1 |
| C3i—C1—H1 | 119.6 | C7—C6—H6B | 109.1 |
| C2—C1—H1 | 119.6 | C5—C6—H6B | 109.1 |
| C1—C2—C3 | 121.5 (2) | H6A—C6—H6B | 107.9 |
| C1—C2—Br1 | 119.81 (16) | C8—C7—C6 | 112.7 (2) |
| C3—C2—Br1 | 118.73 (16) | C8—C7—H7A | 109.1 |
| O1—C3—C1i | 125.49 (19) | C6—C7—H7A | 109.1 |
| O1—C3—C2 | 116.8 (2) | C8—C7—H7B | 109.1 |
| C1i—C3—C2 | 117.70 (19) | C6—C7—H7B | 109.1 |
| O1—C4—C5 | 107.30 (19) | H7A—C7—H7B | 107.8 |
| O1—C4—H4A | 110.3 | C7—C8—C9 | 112.5 (3) |
| C5—C4—H4A | 110.3 | C7—C8—H8A | 109.1 |
| O1—C4—H4B | 110.3 | C9—C8—H8A | 109.1 |
| C5—C4—H4B | 110.3 | C7—C8—H8B | 109.1 |
| H4A—C4—H4B | 108.5 | C9—C8—H8B | 109.1 |
| C4—C5—C6 | 111.0 (2) | H8A—C8—H8B | 107.8 |
| C4—C5—H5A | 109.4 | C8—C9—H9A | 109.5 |
| C6—C5—H5A | 109.4 | C8—C9—H9B | 109.5 |
| C4—C5—H5B | 109.4 | H9A—C9—H9B | 109.5 |
| C6—C5—H5B | 109.4 | C8—C9—H9C | 109.5 |
| H5A—C5—H5B | 108.0 | H9A—C9—H9C | 109.5 |
| C7—C6—C5 | 112.4 (2) | H9B—C9—H9C | 109.5 |
| C3i—C1—C2—C3 | −0.4 (4) | Br1—C2—C3—C1i | −178.52 (18) |
| C3i—C1—C2—Br1 | 178.49 (18) | C3—O1—C4—C5 | −178.7 (2) |
| C4—O1—C3—C1i | 3.4 (4) | O1—C4—C5—C6 | 179.1 (2) |
| C4—O1—C3—C2 | −176.9 (2) | C4—C5—C6—C7 | 178.1 (2) |
| C1—C2—C3—O1 | −179.4 (2) | C5—C6—C7—C8 | −179.8 (2) |
| Br1—C2—C3—O1 | 1.7 (3) | C6—C7—C8—C9 | −175.4 (2) |
| C1—C2—C3—C1i | 0.4 (4) |
| Symmetry codes: (i) −x, −y+1, −z. |
Ali, B. F., Al-Far, R. H. & Haddad, S. F. (2008). Acta Cryst. E64, m751–m752.
Brammer, L. (2004). Chem. Soc. Rev. 33, 476–489.
Bruker (2004). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Desiraju, G. R. & Parthasarathy, R. (1989). J. Am. Chem. Soc. 111, 8725–8726.
Kuriger, T. M., Moratti, S. C. & Simpson, J. (2008). Acta Cryst. E64, o709.
Maruyama, S. & Kawanishi, Y. (2002). J. Mater. Chem. 12, 2245–2249.
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Noncovalent interactions play an important role in designing superstructures (Brammer, 2004). Among these weak forces, the intermolecular interactions between halogen atoms have been a subject of interest (Desiraju et al., 1989). In order to gain more insight into the structure-regulating ability of intermolecular Br···Br interactions, herein we report the crystal structure of the title compound.
A view of the centrosymmetric molecular structure of the title compound is given in Fig.1. The alkyl chains are in the fully extended all-trans conformation and each of them is almost perfectly planar. The C—C—O—C torsion angles of 3.4 (4)o, indicate that the two alkyl chains are coplanar with the benzene ring. The crystal structure of the titile compound reveals the presence of a near linear C—Br···Br fragment[C—Br···Br=155.6 (3)o], the Br···Br distance (3.410 Å) is shorter than the sum of van der Waals radii(3.72 Å) and those in the other compound [3.634 (4)–3.9527 (9) Å](Kuriger et al., 2008; Ali et al., 2008). Owing to the intermolecular Br···Br interactions, the crystal structure of the title compound is extended to a one-dimensional chain structure. The chains are intercalated by van der Waals forces (Fig.2).