organic compounds
3,5-Dichlorosalicylaldehyde
aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: seikweng@um.edu.my
The title compound (systematic name: 3,5-dichloro-2-hydroxybenzaldehyde), C7H4Cl2O2, crystallizes as discrete molecules, the conformation of which may be influenced by an intramolecular hydroxy–carbonyl O—H⋯O hydrogen bond.
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).
Supporting information
10.1107/S1600536808011021/lh2606sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808011021/lh2606Isup2.hkl
The compound was purchased from Aldrich Chemical Company; the chemical exists as colorless prismatic crystals. The bulk chemical has a yellow color.
Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 Å) and were included in the
in the riding model approximation, with U(H) set to 1.2U(C). The oxygen-bound H atom was located in a difference Fourier map, and was refined with a distance restraint of O–H 0.84±0.01 Å; its temperature factor was freely refined.Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).Fig. 1. 70% Probability thermal ellipsoid plot of 3,5-dichlorosalicylaldehyde. Hydrogen atoms are drawn as spheres of arbitrary radius. |
C7H4Cl2O2 | F(000) = 384 |
Mr = 191.00 | Dx = 1.736 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3128 reflections |
a = 8.2823 (2) Å | θ = 3.0–28.2° |
b = 13.7412 (3) Å | µ = 0.82 mm−1 |
c = 7.0973 (2) Å | T = 100 K |
β = 115.185 (2)° | Block, colorless |
V = 730.95 (3) Å3 | 0.25 × 0.15 × 0.05 mm |
Z = 4 |
Bruker SMART APEXII diffractometer | 1672 independent reflections |
Radiation source: fine-focus sealed tube | 1303 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.058 |
ω scans | θmax = 27.5°, θmin = 2.7° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −10→10 |
Tmin = 0.701, Tmax = 0.960 | k = −17→17 |
8436 measured reflections | l = −9→9 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.101 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0416P)2 + 0.8939P] where P = (Fo2 + 2Fc2)/3 |
1672 reflections | (Δ/σ)max = 0.001 |
104 parameters | Δρmax = 0.59 e Å−3 |
1 restraint | Δρmin = −0.49 e Å−3 |
C7H4Cl2O2 | V = 730.95 (3) Å3 |
Mr = 191.00 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.2823 (2) Å | µ = 0.82 mm−1 |
b = 13.7412 (3) Å | T = 100 K |
c = 7.0973 (2) Å | 0.25 × 0.15 × 0.05 mm |
β = 115.185 (2)° |
Bruker SMART APEXII diffractometer | 1672 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1303 reflections with I > 2σ(I) |
Tmin = 0.701, Tmax = 0.960 | Rint = 0.058 |
8436 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 1 restraint |
wR(F2) = 0.101 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.59 e Å−3 |
1672 reflections | Δρmin = −0.49 e Å−3 |
104 parameters |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.17794 (9) | 0.14230 (4) | 0.48280 (10) | 0.01972 (18) | |
Cl2 | 0.15345 (9) | 0.53148 (4) | 0.39904 (11) | 0.02166 (19) | |
O1 | 0.5328 (3) | 0.17615 (13) | 0.8080 (3) | 0.0200 (4) | |
H1 | 0.631 (3) | 0.192 (3) | 0.905 (4) | 0.038 (10)* | |
O2 | 0.7916 (3) | 0.28892 (14) | 1.0580 (3) | 0.0252 (4) | |
C1 | 0.4488 (3) | 0.25960 (17) | 0.7232 (4) | 0.0155 (5) | |
C2 | 0.2766 (3) | 0.25497 (17) | 0.5629 (4) | 0.0164 (5) | |
C3 | 0.1851 (4) | 0.33804 (17) | 0.4659 (4) | 0.0168 (5) | |
H3 | 0.0680 | 0.3339 | 0.3572 | 0.020* | |
C4 | 0.2680 (4) | 0.42815 (17) | 0.5306 (4) | 0.0177 (5) | |
C5 | 0.4355 (4) | 0.43592 (17) | 0.6906 (4) | 0.0179 (5) | |
H5 | 0.4890 | 0.4980 | 0.7336 | 0.021* | |
C6 | 0.5266 (3) | 0.35155 (17) | 0.7897 (4) | 0.0160 (5) | |
C7 | 0.7028 (4) | 0.35892 (18) | 0.9634 (4) | 0.0206 (6) | |
H7 | 0.7517 | 0.4220 | 1.0058 | 0.025* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0225 (3) | 0.0110 (3) | 0.0228 (3) | −0.0036 (2) | 0.0068 (3) | −0.0026 (2) |
Cl2 | 0.0204 (3) | 0.0122 (3) | 0.0276 (4) | 0.0029 (2) | 0.0056 (3) | 0.0051 (2) |
O1 | 0.0193 (10) | 0.0111 (8) | 0.0243 (11) | 0.0025 (7) | 0.0042 (9) | 0.0025 (7) |
O2 | 0.0211 (10) | 0.0197 (9) | 0.0272 (11) | 0.0004 (8) | 0.0030 (9) | 0.0033 (8) |
C1 | 0.0182 (13) | 0.0111 (10) | 0.0180 (12) | 0.0028 (9) | 0.0083 (11) | 0.0016 (9) |
C2 | 0.0216 (13) | 0.0106 (10) | 0.0186 (12) | −0.0017 (9) | 0.0100 (11) | −0.0016 (9) |
C3 | 0.0163 (13) | 0.0162 (12) | 0.0172 (13) | −0.0004 (9) | 0.0063 (11) | −0.0007 (9) |
C4 | 0.0201 (14) | 0.0114 (11) | 0.0213 (13) | 0.0038 (9) | 0.0086 (12) | 0.0032 (9) |
C5 | 0.0202 (14) | 0.0108 (11) | 0.0228 (14) | −0.0024 (9) | 0.0093 (12) | 0.0000 (9) |
C6 | 0.0151 (13) | 0.0123 (11) | 0.0195 (13) | −0.0004 (9) | 0.0064 (11) | 0.0003 (9) |
C7 | 0.0212 (14) | 0.0149 (12) | 0.0229 (14) | −0.0029 (10) | 0.0068 (12) | −0.0003 (10) |
Cl1—C2 | 1.730 (2) | C3—C4 | 1.395 (3) |
Cl2—C4 | 1.742 (2) | C3—H3 | 0.9500 |
O1—C1 | 1.343 (3) | C4—C5 | 1.373 (4) |
O1—H1 | 0.840 (10) | C5—C6 | 1.399 (3) |
O2—C7 | 1.223 (3) | C5—H5 | 0.9500 |
C1—C2 | 1.397 (4) | C6—C7 | 1.459 (4) |
C1—C6 | 1.406 (3) | C7—H7 | 0.9500 |
C2—C3 | 1.381 (3) | ||
C1—O1—H1 | 107 (3) | C5—C4—Cl2 | 120.53 (19) |
O1—C1—C2 | 118.7 (2) | C3—C4—Cl2 | 117.9 (2) |
O1—C1—C6 | 122.7 (2) | C4—C5—C6 | 119.4 (2) |
C2—C1—C6 | 118.5 (2) | C4—C5—H5 | 120.3 |
C3—C2—C1 | 121.5 (2) | C6—C5—H5 | 120.3 |
C3—C2—Cl1 | 119.6 (2) | C5—C6—C1 | 120.3 (2) |
C1—C2—Cl1 | 118.96 (18) | C5—C6—C7 | 119.9 (2) |
C2—C3—C4 | 118.7 (2) | C1—C6—C7 | 119.8 (2) |
C2—C3—H3 | 120.6 | O2—C7—C6 | 124.1 (2) |
C4—C3—H3 | 120.6 | O2—C7—H7 | 118.0 |
C5—C4—C3 | 121.6 (2) | C6—C7—H7 | 118.0 |
O1—C1—C2—C3 | −178.3 (2) | Cl2—C4—C5—C6 | −178.17 (19) |
C6—C1—C2—C3 | 2.0 (4) | C4—C5—C6—C1 | 1.3 (4) |
O1—C1—C2—Cl1 | 0.8 (3) | C4—C5—C6—C7 | −178.4 (2) |
C6—C1—C2—Cl1 | −178.90 (18) | O1—C1—C6—C5 | 177.7 (2) |
C1—C2—C3—C4 | 0.1 (4) | C2—C1—C6—C5 | −2.7 (4) |
Cl1—C2—C3—C4 | −179.03 (19) | O1—C1—C6—C7 | −2.6 (4) |
C2—C3—C4—C5 | −1.5 (4) | C2—C1—C6—C7 | 177.1 (2) |
C2—C3—C4—Cl2 | 177.52 (18) | C5—C6—C7—O2 | −179.8 (3) |
C3—C4—C5—C6 | 0.9 (4) | C1—C6—C7—O2 | 0.5 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2 | 0.84 (1) | 1.87 (2) | 2.628 (3) | 149 (3) |
Experimental details
Crystal data | |
Chemical formula | C7H4Cl2O2 |
Mr | 191.00 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 8.2823 (2), 13.7412 (3), 7.0973 (2) |
β (°) | 115.185 (2) |
V (Å3) | 730.95 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.82 |
Crystal size (mm) | 0.25 × 0.15 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEXII diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.701, 0.960 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8436, 1672, 1303 |
Rint | 0.058 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.101, 1.05 |
No. of reflections | 1672 |
No. of parameters | 104 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.59, −0.49 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2 | 0.84 (1) | 1.87 (2) | 2.628 (3) | 149 (3) |
Acknowledgements
We thank the University of Malaya for the purchase of the diffractometer.
References
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Filarowski, A., Koll, A., Kochel, A., Kalenik, J. & Hansen, P. E. (2004). J. Mol. Struct. 700, 67–72. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2008). publCIF. In preparation. Google Scholar
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The intramolecular hydrogen bonds in small molecules such as ortho-hydroxyacetopheonone and its derivatives has been extensively studied, both theoretically and crystallographically. Such compounds can exist in a keto-enol equilibrium. For 3',5'-dichloroacetophenone, geometry-optimization calculations suggest that the presence of two chlorine substituents raises the acidity of the hydroxyl proton and decreases the basicity of the carbonyl function. The O···O distance in the hydrogen bond is 2.567 (3) Å (Filarowski et al., 2004).
The hydrogen bond in the title molecule (I) is longer with an O···O distance of 2.628 (3) Å. 3,5-Dichlorosalicylaldehyde (I) exists as a monomeric compound (Fig. 1); the molecule is flat and all bond dimensions are normal.