Acta Cryst. (2007). E63, o2826 [ doi:10.1107/S1600536807021472 ]
The molecular structure of the title compound, C11H6Br2O3, contains a planar coumarin ring system which makes a dihedral angle of 18.5 (1)° with the bromoacetyl group. The structure is stabilized by intermolecular C-H
O hydrogen bonds and ![[pi]](/logos/entities/pi_rmgif.gif)
- aromatic stacking interactions, with centroid-centroid distances of 3.567 (2) (symmetry code: -x, -y, -z) and 3.642 (2) Å (-x + 1, -y, -z). A short BrBr [3.4605 (8) Å] contact also stabilizes the crystal structure.
To a solution of compound (I) (4.7 g, 0.025 mol) in 20 ml of alcohol free chloroform, bromine (7.9 g, 0.05 mol) was added in 25 ml of chloroform, with intermittent shaking. The mixture was warmed to decompose an addition product. heated for 15 min on a water bath to expel most of the hydrogen bromide, cooled and filtered. The solid on washing with ether gave 6.98 g (81%) of almost pure product, which on crystallization from acetic acid gave colorless crystals of (I).
All the H atoms were located in a difference Fourier map and refined isotropically with C—H bond lengths in the range 0.89 (4)–0.94 (3) Å.
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1999) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: PLATON (Spek, 2003).
![[Figure 1]](./sj2309fig1thm.gif)
| Fig. 1. The structure of (I) drawn with 50% ellipsoidal probability. |
![[Figure 2]](./sj2309fig2thm.gif)
| Fig. 2. Packing diagram of compound (I) highlighting the C—H···O and π···π contacts. Cg1 and Cg2 are the centroids of the pyranone O1/C7 and benzene C1/C6 rings. Hydrogen bonds are drawn and ring centroids are joined by dotted lines. |
| C11H6Br2O3 | Z = 2 |
| Mr = 345.98 | F(000) = 332 |
| Triclinic, P1 | Dx = 2.073 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
| a = 7.1998 (17) Å | Cell parameters from 565 reflections |
| b = 8.969 (2) Å | θ = 1.6–26.4° |
| c = 9.722 (2) Å | µ = 7.30 mm−1 |
| α = 69.094 (5)° | T = 2930 K |
| β = 85.974 (6)° | Block, yellow |
| γ = 71.177 (4)° | 0.25 × 0.20 × 0.20 mm |
| V = 554.4 (2) Å3 |
| Bruker SMART CCD area-detector diffractometer | 2184 independent reflections |
| Radiation source: fine-focus sealed tube | 1885 reflections with I > 2σ(I) |
| graphite | Rint = 0.030 |
| φ and ω scans | θmax = 26.4°, θmin = 2.3° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→8 |
| Tmin = 0.189, Tmax = 0.232 | k = −11→11 |
| 5722 measured reflections | l = −12→12 |
| 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)] = 0.029 | All H-atom parameters refined |
| wR(F2) = 0.076 | w = 1/[σ2(Fo2) + (0.0344P)2 + 0.543P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.05 | (Δ/σ)max < 0.001 |
| 2184 reflections | Δρmax = 0.57 e Å−3 |
| 170 parameters | Δρmin = −0.88 e Å−3 |
| 0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.027 (2) |
| C11H6Br2O3 | γ = 71.177 (4)° |
| Mr = 345.98 | V = 554.4 (2) Å3 |
| Triclinic, P1 | Z = 2 |
| a = 7.1998 (17) Å | Mo Kα radiation |
| b = 8.969 (2) Å | µ = 7.30 mm−1 |
| c = 9.722 (2) Å | T = 2930 K |
| α = 69.094 (5)° | 0.25 × 0.20 × 0.20 mm |
| β = 85.974 (6)° |
| Bruker SMART CCD area-detector diffractometer | 2184 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1885 reflections with I > 2σ(I) |
| Tmin = 0.189, Tmax = 0.232 | Rint = 0.030 |
| 5722 measured reflections | θmax = 26.4° |
| R[F2 > 2σ(F2)] = 0.029 | All H-atom parameters refined |
| wR(F2) = 0.076 | Δρmax = 0.57 e Å−3 |
| S = 1.05 | Δρmin = −0.88 e Å−3 |
| 2184 reflections | Absolute structure: ? |
| 170 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 | 0.13625 (5) | 0.36757 (5) | 0.37268 (4) | 0.04873 (15) | |
| Br2 | −0.32868 (6) | 0.45590 (5) | 0.37414 (4) | 0.05603 (16) | |
| O1 | 0.2817 (3) | −0.0994 (2) | 0.1884 (2) | 0.0345 (5) | |
| O2 | 0.1724 (4) | −0.0165 (3) | 0.3736 (2) | 0.0468 (6) | |
| O3 | −0.1836 (3) | 0.4487 (3) | 0.0802 (2) | 0.0395 (5) | |
| C4 | 0.1934 (4) | 0.0809 (4) | −0.0648 (3) | 0.0282 (6) | |
| C1 | 0.4394 (5) | −0.1793 (5) | −0.1471 (4) | 0.0453 (8) | |
| C2 | 0.3357 (5) | −0.0283 (5) | −0.2541 (4) | 0.0461 (9) | |
| C3 | 0.2151 (5) | 0.1004 (4) | −0.2145 (4) | 0.0381 (7) | |
| C5 | 0.2981 (4) | −0.0728 (4) | 0.0405 (3) | 0.0289 (6) | |
| C6 | 0.4211 (5) | −0.2033 (4) | 0.0004 (4) | 0.0386 (7) | |
| C7 | 0.0709 (4) | 0.2073 (4) | −0.0126 (3) | 0.0262 (6) | |
| C8 | 0.0564 (4) | 0.1833 (3) | 0.1321 (3) | 0.0245 (5) | |
| C9 | 0.1687 (4) | 0.0216 (3) | 0.2422 (3) | 0.0296 (6) | |
| C10 | −0.0809 (4) | 0.3233 (3) | 0.1739 (3) | 0.0283 (6) | |
| C11 | −0.0879 (5) | 0.3081 (4) | 0.3347 (3) | 0.0345 (7) | |
| H1 | 0.517 (5) | −0.277 (4) | −0.164 (3) | 0.035 (8)* | |
| H2 | 0.350 (6) | −0.018 (5) | −0.348 (5) | 0.053 (11)* | |
| H3 | 0.157 (5) | 0.203 (5) | −0.283 (4) | 0.043 (10)* | |
| H6 | 0.484 (6) | −0.300 (5) | 0.072 (4) | 0.054 (11)* | |
| H7 | 0.002 (5) | 0.307 (5) | −0.078 (4) | 0.039 (9)* | |
| H11 | −0.078 (5) | 0.200 (5) | 0.397 (4) | 0.043 (10)* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br1 | 0.0557 (2) | 0.0580 (3) | 0.0382 (2) | −0.01529 (18) | −0.00347 (15) | −0.02506 (17) |
| Br2 | 0.0527 (3) | 0.0579 (3) | 0.0504 (2) | −0.00193 (18) | 0.01973 (17) | −0.02811 (19) |
| O1 | 0.0362 (11) | 0.0262 (10) | 0.0330 (11) | 0.0015 (9) | −0.0035 (9) | −0.0104 (9) |
| O3 | 0.0463 (13) | 0.0281 (11) | 0.0339 (11) | 0.0012 (10) | −0.0012 (10) | −0.0102 (9) |
| C10 | 0.0317 (15) | 0.0268 (14) | 0.0282 (14) | −0.0116 (12) | 0.0053 (11) | −0.0108 (12) |
| C8 | 0.0267 (14) | 0.0221 (13) | 0.0244 (13) | −0.0080 (11) | 0.0018 (10) | −0.0080 (11) |
| C4 | 0.0292 (14) | 0.0297 (14) | 0.0297 (15) | −0.0133 (12) | 0.0058 (11) | −0.0125 (12) |
| C11 | 0.0388 (17) | 0.0306 (16) | 0.0299 (15) | −0.0056 (13) | 0.0095 (12) | −0.0121 (13) |
| C7 | 0.0284 (14) | 0.0221 (13) | 0.0270 (14) | −0.0095 (11) | 0.0013 (11) | −0.0061 (11) |
| C9 | 0.0311 (15) | 0.0263 (14) | 0.0295 (15) | −0.0076 (12) | 0.0015 (11) | −0.0092 (12) |
| C5 | 0.0232 (13) | 0.0326 (15) | 0.0347 (15) | −0.0088 (11) | 0.0025 (11) | −0.0165 (12) |
| O2 | 0.0617 (16) | 0.0375 (12) | 0.0249 (12) | −0.0004 (11) | 0.0004 (10) | −0.0055 (9) |
| C3 | 0.0438 (18) | 0.0430 (19) | 0.0318 (17) | −0.0180 (15) | 0.0075 (14) | −0.0156 (15) |
| C1 | 0.0332 (17) | 0.056 (2) | 0.064 (2) | −0.0149 (16) | 0.0159 (16) | −0.0424 (19) |
| C2 | 0.050 (2) | 0.062 (2) | 0.041 (2) | −0.0258 (18) | 0.0204 (16) | −0.0328 (18) |
| C6 | 0.0262 (15) | 0.0370 (17) | 0.055 (2) | −0.0039 (13) | 0.0006 (14) | −0.0248 (16) |
| Br1—C11 | 1.951 (3) | C11—H11 | 0.92 (4) |
| Br2—C11 | 1.922 (3) | C7—H7 | 0.90 (4) |
| O1—C5 | 1.374 (4) | C9—O2 | 1.199 (4) |
| O1—C9 | 1.375 (3) | C5—C6 | 1.384 (4) |
| O3—C10 | 1.212 (3) | C3—C2 | 1.363 (5) |
| C10—C8 | 1.492 (4) | C3—H3 | 0.90 (4) |
| C10—C11 | 1.519 (4) | C1—C6 | 1.375 (5) |
| C8—C7 | 1.347 (4) | C1—C2 | 1.387 (6) |
| C8—C9 | 1.470 (4) | C1—H1 | 0.94 (3) |
| C4—C5 | 1.395 (4) | C2—H2 | 0.89 (4) |
| C4—C3 | 1.407 (4) | C6—H6 | 0.90 (4) |
| C4—C7 | 1.422 (4) | ||
| C5—O1—C9 | 123.3 (2) | O2—C9—O1 | 116.4 (3) |
| O3—C10—C8 | 120.2 (3) | O2—C9—C8 | 127.2 (3) |
| O3—C10—C11 | 120.5 (3) | O1—C9—C8 | 116.3 (2) |
| C8—C10—C11 | 119.3 (2) | O1—C5—C6 | 117.7 (3) |
| C7—C8—C9 | 119.9 (2) | O1—C5—C4 | 120.7 (2) |
| C7—C8—C10 | 117.6 (2) | C6—C5—C4 | 121.6 (3) |
| C9—C8—C10 | 122.5 (2) | C2—C3—C4 | 120.3 (3) |
| C5—C4—C3 | 118.2 (3) | C2—C3—H3 | 121 (2) |
| C5—C4—C7 | 117.4 (3) | C4—C3—H3 | 118 (2) |
| C3—C4—C7 | 124.5 (3) | C6—C1—C2 | 121.0 (3) |
| C10—C11—Br2 | 111.9 (2) | C6—C1—H1 | 113 (2) |
| C10—C11—Br1 | 105.6 (2) | C2—C1—H1 | 126 (2) |
| Br2—C11—Br1 | 110.47 (15) | C3—C2—C1 | 120.3 (3) |
| C10—C11—H11 | 112 (2) | C3—C2—H2 | 121 (3) |
| Br2—C11—H11 | 107 (2) | C1—C2—H2 | 119 (3) |
| Br1—C11—H11 | 110 (2) | C1—C6—C5 | 118.6 (3) |
| C8—C7—C4 | 122.3 (3) | C1—C6—H6 | 123 (3) |
| C8—C7—H7 | 118 (2) | C5—C6—H6 | 118 (3) |
| C4—C7—H7 | 119 (2) | ||
| O3—C10—C8—C7 | 4.5 (4) | C7—C8—C9—O1 | −1.3 (4) |
| C11—C10—C8—C7 | −174.4 (3) | C10—C8—C9—O1 | 176.6 (2) |
| O3—C10—C8—C9 | −173.4 (3) | C9—O1—C5—C6 | 178.2 (3) |
| C11—C10—C8—C9 | 7.6 (4) | C9—O1—C5—C4 | −2.0 (4) |
| O3—C10—C11—Br2 | 21.6 (4) | C3—C4—C5—O1 | −179.6 (3) |
| C8—C10—C11—Br2 | −159.5 (2) | C7—C4—C5—O1 | 0.1 (4) |
| O3—C10—C11—Br1 | −98.7 (3) | C3—C4—C5—C6 | 0.3 (4) |
| C8—C10—C11—Br1 | 80.3 (3) | C7—C4—C5—C6 | 180.0 (3) |
| C9—C8—C7—C4 | −0.4 (4) | C5—C4—C3—C2 | −0.1 (5) |
| C10—C8—C7—C4 | −178.4 (2) | C7—C4—C3—C2 | −179.7 (3) |
| C5—C4—C7—C8 | 1.0 (4) | C4—C3—C2—C1 | −0.5 (5) |
| C3—C4—C7—C8 | −179.3 (3) | C6—C1—C2—C3 | 0.9 (5) |
| C5—O1—C9—O2 | −177.7 (3) | C2—C1—C6—C5 | −0.7 (5) |
| C5—O1—C9—C8 | 2.5 (4) | O1—C5—C6—C1 | 179.9 (3) |
| C7—C8—C9—O2 | 178.9 (3) | C4—C5—C6—C1 | 0.1 (5) |
| C10—C8—C9—O2 | −3.2 (5) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C11—H11···O2i | 0.92 (4) | 2.46 (4) | 3.278 (4) | 148 (3) |
| Symmetry codes: (i) −x, −y, −z+1. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C11—H11···O2i | 0.92 (4) | 2.46 (4) | 3.278 (4) | 148 (3) |
| Symmetry codes: (i) −x, −y, −z+1. |
The authors thank the Department of Science and Technology for data collection on the CCD facility under the IRHPA-DST scheme. DC thanks CSIR, India, and the IISc for a Senior Research Fellowship.
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Coumarins are an important class of organic compounds with vast structural diversity and find useful applications in synthetic chemistry, medicinal chemistry and photochemistry (Vishnumurthy et al., 1996, 1997, 1999). The formation of [2 + 2] cycloaddition products upon irradiation (Vishnumurthy et al., 2001) of coumarin and its derivatives has demonstrated the importance of preorganization of molecules in the crystalline solid state.
In the title compound, (I) (Fig. 1, Table 1), the coumarin system is planar, with maximum deviations of 0.012 (4)Å and 0.018 (3)Å for atoms C1 and C9 respectively.
The molecules are held by C—H···O intermolecular hydrogen bonds forming dimeric units. A pair of such dimers are stabilized by Br2···Br2 short contacts [d = 3.4605 Å, symmetry code: -x - 1, -y + 1, -z + 1], [Fig. 2]. Furthermore, π···π stacking interactions link Cg1..Cg2, (the centroids of the pyanone O, C4···C9 and benzene C1···C6 rings) with separations of 3.567 (2), [Symmetry code: -x, -y, -z] and 3.642 (2)Å -x + 1, -y, -z] respectively between the centroids, Fig. 2.