Acta Cryst. (2008). E64, o1080 [ doi:10.1107/S1600536808013901 ]
The title compound, C7H4Cl2O2, exhibits a layer crystal structure; molecules within each layer are linked by weak C-H
O intermolecular hydrogen bonds. There is also an intramolecular O-HO hydrogen bond.
The title compound was obtained as received. Single crystals suitable for X-ray diffraction measurement were formed after 6 days in methanol by slow evaporation at room temperature in air. Analysis calculated for C7H4O2Cl2: C 44.02, H 2.11%. Found: C 44.18, H, 2.24%. FT—IR (KBr pellets, cm-1): 3066(versus), 2856(s), 1666(versus), 1604(m), 1428(s), 1375(versus), 1276(s), 1208(s), 1171(s), 1103(m), 935(s), 891(versus), 735(s), 703(s), 566(m), and 515(m).
The H atoms were placed in geometrically idealized positions (C—H = 0.93 Å and O—H = 0.82 Å) and refined as riding atoms, with Uiso(H) = 1.2Ueq(C) and Uiso(H) = 1.5Ueq(O).
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./at2566fig1thm.gif)
| Fig. 1. An ORTEP drawing of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. |
![[Figure 2]](./at2566fig2thm.gif)
| Fig. 2. A perspective view of the intralayer intermolecular hydrogen-bond contacts among molecules in the title compound. Hydrogen bonds and Cl···Cl interactions are shown as dashed lines. [Symmetry codes: (i) x+1, y, z; (ii) -x + 1, y+1/2, -z+1/2; (iii) -x+2, y - 1/2, -z + 1/2]. |
![[Figure 3]](./at2566fig3thm.gif)
| Fig. 3. A perspective view of the layer packing structure of (I) together with the unit cell. |
| C7H4Cl2O2 | F000 = 384 |
| Mr = 191.00 | Dx = 1.666 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 1691 reflections |
| a = 8.3359 (16) Å | θ = 2.7–26.8º |
| b = 13.884 (3) Å | µ = 0.79 mm−1 |
| c = 7.2341 (14) Å | T = 291 (2) K |
| β = 114.519 (2)º | Block, yellow |
| V = 761.7 (3) Å3 | 0.14 × 0.12 × 0.10 mm |
| Z = 4 |
| Bruker SMART CCD area-detector diffractometer | 1487 independent reflections |
| Radiation source: fine-focus sealed tube | 1181 reflections with I > 2σ(I) |
| Monochromator: graphite | Rint = 0.055 |
| T = 291(2) K | θmax = 26.0º |
| φ and ω scans | θmin = 2.7º |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −10→10 |
| Tmin = 0.898, Tmax = 0.925 | k = −16→16 |
| 4063 measured reflections | l = −7→8 |
| 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)] = 0.036 | H-atom parameters constrained |
| wR(F2) = 0.097 | w = 1/[σ2(Fo2) + (0.0536P)2] where P = (Fo2 + 2Fc2)/3 |
| S = 0.99 | (Δ/σ)max < 0.001 |
| 1487 reflections | Δρmax = 0.27 e Å−3 |
| 101 parameters | Δρmin = −0.23 e Å−3 |
| Primary atom site location: structure-invariant direct methods | Extinction correction: none |
| C7H4Cl2O2 | V = 761.7 (3) Å3 |
| Mr = 191.00 | Z = 4 |
| Monoclinic, P21/c | Mo Kα |
| a = 8.3359 (16) Å | µ = 0.79 mm−1 |
| b = 13.884 (3) Å | T = 291 (2) K |
| c = 7.2341 (14) Å | 0.14 × 0.12 × 0.10 mm |
| β = 114.519 (2)º |
| Bruker SMART CCD area-detector diffractometer | 1487 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | 1181 reflections with I > 2σ(I) |
| Tmin = 0.898, Tmax = 0.925 | Rint = 0.055 |
| 4063 measured reflections |
| R[F2 > 2σ(F2)] = 0.036 | 101 parameters |
| wR(F2) = 0.097 | H-atom parameters constrained |
| S = 0.99 | Δρmax = 0.27 e Å−3 |
| 1487 reflections | Δρmin = −0.23 e Å−3 |
Experimental. The structure was solved by direct methods (Bruker, 2000) and successive difference Fourier syntheses. |
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 | ||
| C1 | 0.4748 (2) | 0.35190 (14) | 0.2605 (3) | 0.0419 (5) | |
| C2 | 0.5509 (2) | 0.26110 (14) | 0.2721 (3) | 0.0383 (4) | |
| C3 | 0.7213 (2) | 0.25643 (14) | 0.2822 (3) | 0.0379 (4) | |
| C4 | 0.8119 (2) | 0.33830 (13) | 0.2774 (3) | 0.0422 (5) | |
| H4 | 0.9261 | 0.3341 | 0.2858 | 0.051* | |
| C5 | 0.7313 (2) | 0.42742 (15) | 0.2599 (3) | 0.0422 (5) | |
| C6 | 0.5658 (3) | 0.43474 (15) | 0.2547 (3) | 0.0445 (5) | |
| H6 | 0.5145 | 0.4949 | 0.2474 | 0.053* | |
| C7 | 0.2987 (3) | 0.35981 (17) | 0.2606 (3) | 0.0536 (6) | |
| H7 | 0.2525 | 0.4210 | 0.2579 | 0.064* | |
| Cl1 | 0.81885 (7) | 0.14449 (4) | 0.29976 (9) | 0.0542 (2) | |
| Cl2 | 0.84604 (7) | 0.52989 (4) | 0.24617 (10) | 0.0612 (2) | |
| O1 | 0.21042 (19) | 0.29062 (13) | 0.2640 (3) | 0.0678 (5) | |
| O2 | 0.46796 (18) | 0.17843 (10) | 0.2737 (2) | 0.0519 (4) | |
| H2 | 0.3694 | 0.1904 | 0.2670 | 0.078* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0364 (10) | 0.0424 (12) | 0.0505 (11) | 0.0021 (8) | 0.0216 (9) | 0.0031 (9) |
| C2 | 0.0405 (10) | 0.0354 (11) | 0.0423 (10) | −0.0011 (8) | 0.0206 (8) | 0.0018 (8) |
| C3 | 0.0389 (10) | 0.0360 (11) | 0.0428 (10) | 0.0048 (8) | 0.0209 (8) | 0.0000 (8) |
| C4 | 0.0357 (10) | 0.0470 (14) | 0.0483 (12) | 0.0007 (8) | 0.0218 (9) | 0.0033 (9) |
| C5 | 0.0410 (11) | 0.0383 (11) | 0.0492 (11) | −0.0052 (8) | 0.0209 (9) | 0.0034 (9) |
| C6 | 0.0432 (11) | 0.0367 (11) | 0.0568 (12) | 0.0050 (8) | 0.0240 (10) | 0.0045 (9) |
| C7 | 0.0427 (12) | 0.0502 (14) | 0.0746 (15) | 0.0042 (10) | 0.0310 (11) | 0.0076 (11) |
| Cl1 | 0.0576 (4) | 0.0406 (3) | 0.0719 (4) | 0.0126 (2) | 0.0344 (3) | 0.0019 (2) |
| Cl2 | 0.0515 (3) | 0.0438 (4) | 0.0914 (5) | −0.0092 (2) | 0.0327 (3) | 0.0102 (3) |
| O1 | 0.0463 (8) | 0.0642 (12) | 0.1052 (13) | −0.0007 (8) | 0.0437 (8) | 0.0073 (9) |
| O2 | 0.0475 (8) | 0.0370 (8) | 0.0773 (10) | −0.0056 (6) | 0.0319 (8) | 0.0020 (7) |
| C1—C6 | 1.388 (3) | C4—H4 | 0.9300 |
| C1—C2 | 1.398 (3) | C5—C6 | 1.369 (3) |
| C1—C7 | 1.472 (3) | C5—Cl2 | 1.740 (2) |
| C2—O2 | 1.342 (2) | C6—H6 | 0.9300 |
| C2—C3 | 1.393 (2) | C7—O1 | 1.217 (3) |
| C3—C4 | 1.373 (3) | C7—H7 | 0.9300 |
| C3—Cl1 | 1.7340 (19) | O2—H2 | 0.8200 |
| C4—C5 | 1.388 (3) | ||
| C6—C1—C2 | 120.59 (18) | C5—C4—H4 | 120.3 |
| C6—C1—C7 | 119.71 (18) | C6—C5—C4 | 120.85 (18) |
| C2—C1—C7 | 119.68 (18) | C6—C5—Cl2 | 120.63 (16) |
| O2—C2—C3 | 118.51 (17) | C4—C5—Cl2 | 118.52 (14) |
| O2—C2—C1 | 123.29 (16) | C5—C6—C1 | 119.68 (18) |
| C3—C2—C1 | 118.20 (17) | C5—C6—H6 | 120.2 |
| C4—C3—C2 | 121.30 (17) | C1—C6—H6 | 120.2 |
| C4—C3—Cl1 | 119.86 (13) | O1—C7—C1 | 123.6 (2) |
| C2—C3—Cl1 | 118.84 (15) | O1—C7—H7 | 118.2 |
| C3—C4—C5 | 119.34 (17) | C1—C7—H7 | 118.2 |
| C3—C4—H4 | 120.3 | C2—O2—H2 | 109.5 |
| D—H···A | D—H | H···A | D···A | D—H···A |
| O2—H2···O1 | 0.82 | 1.92 | 2.630 (2) | 145 |
| C4—H4···O1i | 0.93 | 2.51 | 3.428 (3) | 168 |
| C6—H6···O2ii | 0.93 | 2.56 | 3.394 (3) | 149 |
| Symmetry codes: (i) x+1, y, z; (ii) −x+1, y+1/2, −z+1/2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| O2—H2···O1 | 0.82 | 1.92 | 2.630 (2) | 145 |
| C4—H4···O1i | 0.93 | 2.51 | 3.428 (3) | 168 |
| C6—H6···O2ii | 0.93 | 2.56 | 3.394 (3) | 149 |
| Symmetry codes: (i) x+1, y, z; (ii) −x+1, y+1/2, −z+1/2. |
WH acknowledges the National Natural Science Foundation of China (No. 20301009) and the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry, for financial suppor.
Bruker (2000). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Fan, Y., You, W., Qian, H.-F., Liu, J.-L. & Huang, W. (2008). Acta Cryst. E64, o799.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
We have newly reported the X-ray single-crystal structure of 3,5-dibromo-2-hydroxybenzaldehyde (Fan et al., 2008). In this paper, we report the X-ray single-crystal structure of 3,5-dichloro-2- hydroxybenzaldehyde.
The molecular structure of (I) is illustrated in Fig. 1. The selected bond distances and bond angles are normal. Different from 3,5-dibromo-2-hydroxybenzaldehyde, there is only one crystallographically independent molecule in the asymmetric unit. The molecular geometry of slicylaldehyde unit of (I) is comparable with that of 3,5-dibromo-2-hydroxybenzaldehyde.
In the crystal packing of (I), there are two sets of molecules with the dihedral angle of 6.52 (2) ° and molecules in every layer are linked by intermolecular CO—H···O hydrogen bondings (Fig. 2). A layer packing structure is formed with the mean interlayer separation of 3.428 (2) Å (Fig. 3.). However, no π–π stacking interactions can be observed in (I), which is different from those in 3,5-dibromo-2-hydroxybenzaldehyde.